ПОДЪЕМНОЕ УСТРОЙСТВО И СПОСОБ ПОДЪЕМА СТРЕЛЫ СТРОИТЕЛЬНОЙ МАШИНЫ, И СТРОИТЕЛЬНАЯ МАШИНА С ТАКИМ ПОДЪЕМНЫМ УСТРОЙСТВОМ

Устройство предназначено для подъема стрелы эксплуатируемой машины. Устройство содержит цилиндр (4) и аккумулятор (7), причем цилиндр (4) содержит верхнюю камеру (4a) и нижнюю камеру (4b), а также шток (2) поршня цилиндра, соединенный со стрелой (1), причем верхняя часть аккумулятора (7) заполнена газом, а нижняя часть аккумулятора (7) заполнена гидравлической жидкостью (19) и сообщена с нижней камерой (4b) цилиндра; регулировочный цилиндр (12), содержащий верхнюю камеру (12a) и нижнюю камеру (12b), а также шток (23) поршня, соединенный со стрелой (1); гидравлический насос (9), с помощью которого, при подаче гидравлической жидкости в верхнюю камеру (12a) регулировочного цилиндра, стрела (1) опускается таким образом, что вес стрелы давит на шток (2) поршня цилиндра для выдавливания гидравлической жидкости из нижней камеры (4b) цилиндра в нижнюю часть аккумулятора, для сжимания газа, находящегося в верхней части аккумулятора для регенерирования потенциальной энергии, а при подаче гидравлическим ...

ПРОПОРЦИОНАЛЬНЫЙ ЭЛЕКТРОГИДРАВЛИЧЕСКИЙ РАСПРЕДЕЛИТЕЛЬ НЕПРЯМОГО ДЕЙСТВИЯ

Изобретение относится к электрогидравлической системе управления исполнительными механизмами проходческих комбайнов. Техническим результатом является расширение арсенала пропорциональных электрогидравлических распределителей непрямого действия во взрывозащищенном рудничном исполнении, при одновременном снижении потребляемой мощности с сохранением габаритно присоединительных и весовых характеристик. Пропорциональный электрогидравлический распределитель непрямого действия содержит пилотный пропорциональный распределитель и силовой золотниковый четырехлинейный трехпозиционный гидрораспределитель. Пилотный пропорциональный распределитель жестко свинчен через дроссельную плиту с регулируемыми дросселями с силовым золотниковым четырехлинейным трехпозиционным гидрораспределителем. Пилотный пропорциональный распределитель состоит из гидравлического корпуса с запрессованной в него гильзой, поворотного золотника, зажатого с одной стороны крышкой с упором и с другой стороны через соединительную возвратную ...

ГИДРАВЛИЧЕСКОЕ ВЕНТИЛЬНОЕ УСТРОЙСТВО

Устройство предназначено для распределения рабочей жидкости к нескольким потребителям. Устройство содержит по меньшей мере два распределительных модуля, каждый из которых подключен к каналу высокого и низкого давления, и рабочие отводы, подключение к потребителю, компенсационное устройство, на которое действует давление, имеющееся в средстве определения нагрузки. При этом средство определения нагрузки по меньшей мере одного распределительного модуля содержит приспособление изменения давления, которое отличается от приспособления изменения давления, имеющегося в средстве определения нагрузки другого распределительного модуля. Технический результат заключается в увеличении числа способов управления гидравлическим распределительным устройством. 3 н. и 8 з.п. ф-лы, 1 ил.

БЛОК ВОЗДУХОРАСПРЕДЕЛИТЕЛЯ ДЛЯ ПНЕВМАТИЧЕСКИХ СИСТЕМ УТИЛИТАРНЫХ ТРАНСПОРТНЫХ СРЕДСТВ

Предметом настоящего изобретения является блок воздухораспределителя для пневматических систем утилитарных транспортных средств, используемый, в частности, для распределения сжатого воздуха по отдельным ресиверам систем пневматических тормозов и системы подвески утилитарных транспортных средств. Блок воздухораспределителя содержит верхний наружный модуль 1, один внутренний модуль 11 и нижний наружный модуль 9. Два установочных болта 14, которые фиксируют модули 1, 9, 11, проходят через два установочных сквозных отверстия 3 каждого модуля 1, 9, 11 параллельно центральной оси модулей 1, 9 и 11. Болты 14 выступают над наружными модулями 1, 9 и оканчиваются на каждой стороне резьбовым концом для соединения с рамой транспортного средства. Модули 1, 9 и 11 блока крепятся гайками 16 и пружинными шайбами 17. Технический результат - компактный дизайн, низкий вес, блок не подвержен коррозии, не требует дополнительной защиты и экономит пространство, необходимое для установки его в транспортном средстве ...

ФУНКЦИЯ ОПУСКАНИЯ СПОЙЛЕРА С МЕХАНИЧЕСКОЙ ОБРАТНОЙ СВЯЗЬЮ ДЛЯ УПРАВЛЕНИЯ ГИДРАВЛИЧЕСКИМ КЛАПАНОМ

Differenzdruckrelais

Umschaltweiche zum Anschluß von unabhängigen, doppeltwirkenden Hydraulikzylindern an ein Steuergerät

Umschaltweiche als 6/3-Wegeventilkombination (1) ausgeführt: 1.1 Weiche dargestellt durch zwei 3-Wegeventile 1.2 Umschaltung einfach-/doppeltwirkend dargestellt durch 2-Wegeventil kombiniert mit Rückschlagventil ...

Ventilvorrichtung für ein Fahrzeug

Ventilvorrichtung für ein Fahrzeug, aufweisend ein Gehäuse (101), das ein offenes Ende und ein geschlossenes Ende aufweist, um einen Innenraum (S) zu bilden, und das eine erste und eine zweite Einlassöffnung (102, 104), die ein Getriebefluid von einem Getriebe (5) und einem Ölkühler (9) aufnehmen, eine Bypassöffnung (103), die das Getriebefluid zu dem Getriebe (5) umleitet, und eine Auslassöffnung (105) aufweist, die das Getriebefluid zu dem Ölkühler (9) abführt, eine innere Kappe (110), die wenigstens teilweise in den Innenraum (S) eingesetzt ist, an dem Gehäuse (101) fixiert ist und eine offene Öffnung (111) aufweist, die in den Innenraum (S) eingesetzt ist, eine Betriebseinheit (120), die zwischen der inneren Kappe (110) und dem geschlossenen Ende des Gehäuses (101) angeordnet ist und sich entsprechend einer Temperatur des Getriebefluids hin- und herbewegt, eine Ventileinheit (140), die an der Betriebseinheit (120) angeordnet ist, um die Bypassöffnung (103) und die Auslassöffnung (105 ...

BREMSVENTIL

Druckmittelsteuerung fuer Arbeitsmaschinen

Hydraulic control device

The invention proposes a hydraulic control device (10) with a directional control valve (12) and an associated changeover valve control (14) which, with the aid of restrictors (23, 25, 30), makes possible fine control without notable pressure excesses in the fine-control range. Connected upstream of the changeover valve (14) is a third restrictor (30), which is connected in parallel with a second restrictor (25) in the feed (15) and enlarges the control pressure drop, caused by the changeover valve, as a function of the increased residual flow via the changeover valve. This leads to shallower flow characteristics (72) as a function of the spool stroke (s) of the control spool (45) and hence to better fine control. ...

Verteiler für eine hydraulische Flüssigkeit unter einem gesteuerten Druck

Verteiler, insbesondere hydraulischer Manipulator mit einem Druckregulierer (150) mit einer Bohrung (121), die einen Stößel (160) aufnimmt, der der Wirkung der Steuereinrichtung (110) und Rückstellkräften (172) ausgesetzt ist, einem Schieber (180), der dem Schub des Stößels (160) gegen die Kraft einer Ausgleichsfeder (188) ausgesetzt ist, und einem Hohlraum (123), der die Bohrung (121) vom Stößel und jenem (126) des Schiebers (160) trennt, der die Ausgleichsfeder (188) aufnimmt und mit dem Ausgang zum Reservoir (101) in Verbindung steht. Die Bohrung (121) begrenzt eine Dämpfungskammer (190), die mit Flüssigkeit gefüllt ist, wobei sich das Volumen der Kammer in Abhängigkeit von der Rückkehrbewegung des Stößels (160) verringert.

Steuersystem, Arbeitsmaschine und Steuerverfahren

Steuersystem (9), das eingerichtet ist, eine Arbeitsmaschine (100) zu steuern, die eine Arbeitseinheit (1) enthält, die eine Vielzahl von Arbeitseinheitskomponenten und eine Vielzahl von Aktoren (20) aufweist, die eingerichtet sind, die jeweiligen Arbeitseinheitskomponenten anzutreiben, wobei das Steuersystem (9) Folgendes umfasst:eine erste Hydraulikpumpe (31) und eine zweite Hydraulikpumpe (32);einen Durchgang (55), der die erste Hydraulikpumpe (31) und die zweite Hydraulikpumpe (32) miteinander verbindet;eine Öffnungs-/Schließ-Vorrichtung (67), die in dem Durchgang (55) vorgesehen und eingerichtet ist, den Durchgang zu öffnen und zu schließen;eine Steuervorrichtung (19), die eingerichtet ist, die Öffnungs-/Schließ-Vorrichtung (67) zu steuern, um zwischen einem Strömungsaufteilungszustand, bei dem der Durchgang (55) geschlossen ist und einem verbundenen Zustand, bei dem der Durchgang (55) offen ist, umzuschalten;einen ersten Aktor (21, 22), dem ein Hydraulikfluid, das in dem Strömungsaufteilungszustand ...

Valve arrangement for reducing pressure

To reduce the system pressure to a lower secondary pressure in a part of a hydraulic circuit, a valve arrangement is proposed in which a common pilot-control valve is provided for the pressure-reducing valve and the pressure-relief valve serving to protect the secondary pressure. Both main valves are constructed as built-in valves so that the valve arrangement is suitable in particular for high flow rates and is simple to manufacture.

Steuerung für die Ölbetriebstemperatur einer hydraulischen Antriebseinrichtung

Eine Steuereinrichtung 12 zum Steuern eines Flussratensteuerventil 11 enthält eine erste Recheneinrichtung zum Bestimmen einer Energiekomponente, die Hydrauliköl erwärmt, eine erste Einstelleinrichtung zum Einstellen eines zweiten Verhältnisses zwischen einer Flussrate durch einen Ölkühler 9 und der Energiekomponente, wie diese gemäß einer experimentell Oder empirisch bekannten eingestellt wird, eines ersten Verhältnisses zwischen der Flussrate durch den Ölkühler 9 und einer Menge einer Wärmestrahlung von dem Ölkühler 9 und wie durch Ersetzen der Menge der Wärmestrahlung von dem Ölkühler 9 in dem ersten Verhältnis zu der Energiekomponente erhalten, und eine zweite Recheneinrichtung zum Bestimmen der Flussrate durch den Ölkühler 9 auf der Grundlage der Energiekomponente, bestimmt durch die erste Recheneinrichtung und das zweite Verhältnis, das durch die erste Einstelleinrichtung eingestellt wird und die eingerichtet ist, um dass Flussratensteuerventil 11 gemäß der Flussrate durch den Ölkühler ...

Lastabhaengiges Ventil,insbesondere fuer ein hydraulisches Betaetigungssystem

Verfahren und Vorrichtung zur Steuerung eines Hubzylinders insbesondere von Arbeitsmaschinen

Switching valve for controlling pressurizing agent connection of two valve connections, has main stage formed as seat valve, where seat valve has controlling pressure area

The switching valve has a main stage (1) formed as a seat valve. The seat valve has a controlling pressure area (12). The controlling pressure area is increased with discharge line of a pre-controlling stage connecting a tank (T). A pre-controlling stage has an electromagnetically operated seat valve.

Vorrichtung zur Ableitung von UEber- oder Unterdruck aus den Arbeitskammern einer hydraulischen Anlage

Kombiniertes An- und Einfahrventil fuer hydraulische Hubeinrichtungen wie Aufzuege und Hebebuehnen

MODULARE VENTILANORDNUNG FÜR UNTERSCHIEDLICHE DURCHFLUSSKATEGORIEN

HYDRAULIK-BREMSVENTILANORDNUNG

Steuervorrichtung

Hydraulic relief valve

IMPROVEMENTS IN FLUID PRESSURE CONTROL VALVES

... 1,262,462. Valves. PRIESTMAN BROS. Ltd. 22 July, 1969 [7 Aug., 1968], No. 37632/68. Heading F2V. A valve of the kind which has two contro' members each having a rest position to which it is resiliently urged and from which it is moved to alter the path of fluid flow, comprises a link 18 pivotally interconnecting both control members 8, 11, and an operating member 23 pivotally connected to the link 18, the arrangement being such that initial movement of the member 23 causes movement of one of the control members 11 to its limiting position, and further movement of the operating member 23 causes the movement of the other control member 8 to its limiting position. For equal forces generated by the springs 17, this is achieved by connecting the operating member 23 nearer to one spool 11 than the other 8. The hand lever 27 pivots about fulcrum 28 and is pivotally connected to the operating member 23 at 26.

CONTROL VALVE MEANS FOR FLUID MOTORS

... 1376063 Valves HYDRAULIC INDUSTRIES Inc 21 Jan 1972 [20 May 1971] 3034/72 Heading F2V A control valve 8 for an hydraulic motor has a pressure-reducing valve 29 to limit the rate at which fluid can be exhausted from the motor through passages 32, 31. The load is thus prevented from driving the motor at a faster rate than desired. In the preferred embodiment, the valve spool 8 connects one of a pair of passages 9, 10 to a high-pressure supply passage 11 while the other is connected to an exhaust passage 12 or 13. Two pressure-reducing valves 29 are provided, the valve in the exhaust line being operated against a spring 34 by fluid pressure applied through passages 37, 36 while the other valve 29 is forced to the fully open position by supply pressure applied through passages 17, 40, 42. When the spool 8 is in neutral the latter passages are connected to exhaust through a further passage 44.

An hydraulic actuator

... 1,133,892. Hydraulic control circuits. GENERAL PRECISION SYSTEMS Inc. Dec. 28, 1966 [Jan.14, 1966], No.57956/66. Heading F1P. The supply of working fluid and hence speed of a double-acting hydraulic piston 102, Fig. 7, is maintained constant against a varying reactor torque exerted by a rock shaft 20 driven by the piston 102, by controlling an adjustable orifice 276, 280, Fig. 13, in a by-pass 264, 262 connecting the delivery passage 76 of a constant flow electric motor driven supply pump 14 to a sealed pressurized return reservoir 36; said orifice being varied by a piston 246 held by a spring 252 in constant abutment with the free end of the rod 238 of a sensing piston 226 which assumes a position determined by the pressure difference between chambers 106, 108 either side the actuator piston 102. Pump delivery is connected to one or other chamber 108, 106 through feed passages 78, 80 of a four-way proportioning valve 89 having a spool 90 adjustably positioned by a plunger 91 controlled ...

Safety valve for hydraulic systems

... 1,145,604. Power steering. DANFOSS A/S. 17 March, 1967 [26 March, 1966], No. 12722/67. Heading B7H. [Also in Division F2] A power steering circuit includes an hydraulic actuator 9, 10, 11, connected to the steered wheels, a control unit 4 connected with a steering wheel, a pump 3 driven by a motor 2, a reservoir 1, and a safety valve 18, see Division P2, to relieve fluid pressure from either one of conduits 16 and, 17 leading to the actuator, when an external force acts upon the steered wheels, e.g. if they strike an obstacle. The valve has a single ball closure (23), Fig. 2 (not shown), loaded by a spring (24), and is arranged, when a pressure builds up in one conduit, to relieve to the other or to the reservoir 1.

Improvements in the manufacture and production of hydrocarbons rich in carbon from those poorer in carbon

In the conversion of normally gaseous hydrocarbons into hydrocarbons of higher carbon content, particularly into acetylene, the initial hydrocarbons are first heated sufficiently to convert them in part into normally liquid, particularly aromatic, hydrocarbons; the latter are then separated, without removing any normally gaseous olefines present, and the residual gases are subjected to partial combustion with free oxygen at a temperature above 1000 DEG C. Suitable initial hydrocarbons are methane, ethane, propane, butane, ethylene, propylene and butylene, and gases containing them such as natural gas, coke oven gas, cracking gases, oil-distillation gases, and waste gases from destructive hydrogenation processes. The temperature to which the gaseous hydrocarbon must be heated for the production of normally liquid hydrocarbons varies with the hydrocarbon and the pressure used; thus, for methane at atmospheric pressure a temperature of 900--1000 DEG C. is required, while for propylene or butylene ...

CONTROL DEVICE FOR LOAD-INDEPENDENT REGULATION OF HYDRAULIC CONSUMERS

... 1396926 Fluid-pressure servosystems KOPPEN & LETHEM TRADING CO AG and APPINGEDAMMER BRONSMOTORENFABRIEK NV 14 June 1972 [29 June 1971] 27853/72 Heading G3P [Also in Divisions Fl and F2] Each of a bank of spool valves 2a-2c mounted between a valve block 1 and an end-plate 3 comprises a manually-operable spool 10 adapted to connect either of work ports 6, 7 to supply passage 48 whilst simultaneously connecting the other work port to a respective exhaust passage 50a or 50c, the latter passages being inter-connected by passage 50b in end-plate 3, Fig. 6. Spool 16 in block 1 is adapted to maintain the pressure in supply passage 48 a constant amount greater than the highest pressure prevailing in the work ports currently connected to the supply passage, and in the embodiment shown this is achieved by subjecting the lower end of the spool to supply pressure via passages 17, Fig. 6, and the upper end to a pilot pressure in chamber 52 representing the highest work port pressure, the latter pressure ...

HYDRAULIC CONTROL CIRCUIT

... 1437199 Hydraulic control circuits CATERPILLAR TRACTOR CO 11 June 1973 [21 June 1972] 27613/73 Heading F1P When the pressure of hydraulic liquid in a closed reservoir 10, Fig. 1 rises above a predetermined level, it is relieved by a check-valve 30 which opens the pass liquid through a spool valve to a ram 11. This increase in pressure occurs when a pump 12 is inoperative and the spool 19 is moved to its L position to lower an implement. In this position fluid from the ram 11 flows to the reservoir through passages 18, 23, 24. When valve 30 opens fluid passes to the other end of the ram through passages 37, 33, 34, 17. A check-valve 21 is provided in the passage from the pump to the spool valve.

Improvements in or relating to control valves

... 678,539. Valves. VANZO, M. Sept. 5, 1950 [Sept. 6, 1949], No. 21896/50. Class 135. In a valve structure of the kind provided with inlet, outlet, and exhaust connections and with the inletoutlet and outlet-exhaust passages controlled by separate but interconnected valve closure members, and wherein the exhaust valve closes before the inlet valve opens, the inlet valve comprises an elastic ring clamped at its centre to a carrier which moves axially with respect to the ring, and the latter co-operates with a seat adjacent its outer edge. In an embodiment 1, Fig. 1, indicates the inlet for a pressure fluid and the outlet 2 is connected to a receptacle. In the position shown, the receptacle is connected to an exhaust opening 36 through a chamber 3, passages 35 in an abutment ring 33 slidable on a spindle 22, the space surrounding the spindle where it passes through a resilient washer or seating 27, and then past a valve 21 ; and the inlet 1 is sealed off by a valve disc 9 of resilient material ...

Locking means for hydraulic control valves

... 1,078,618. Remotely operated fastenings. HYDRAULIC UNIT SPECIALTIES CO. Aug. 3, 1965, No. 33159/65. Heading E2A. [Also in Division F2] In an interlock mechanism suitable for a manually operable valve of the "stacked" type (Fig. I not shown) the valve spool (8) whereof is displaceable in either direction from a neutral position to direct pressure fluid to a motor from an open centre passage (9), via a feeder passage (10) and a check valve (11), to either one of a pair of service passages (13 or 14) and exhaust fluid back to a passage (15), via a throttle (17) to an exhaust passage 16, the exhaust fluid, from passage (15) or other passage is connected at 42 to displace a piston 37, within cylinder 36 connected to the valve body 6, carrying a plunger 25 which is slidable against a spring 40 within an inner tubular extension 21 of cylinder 36 to force balls 23 into locking engagement with grooves 24 of an outer tubular member 22, connected to move with the spool 8, which grooves 24 may correspond ...

Hydraulic actuator with veto

... 1,070,254. Hydraulic actuators. ELLIOTT BROS. (LONDON) Ltd. Jan.1, 1964 [Jan. 4, 1963], No.25554/64. Divided out of 1,070,253. Heading F1P. The subject matter is all contained in Specification 1, 070,253; but the claims relate to a hydraulic actuator and not a control arrangement for aircraft.

VALVE SYSTEM FOR CONTROLLING HYDROSTATIC TRANSMISSION

Hydraulic valve arrangement

Servo control device

... 592,621. Fluid-pressure servomotorcontrol systems. JACK & HEINTZ, Inc. Oct. 27, 1944, No. 20989. Convention date, Oct. 8, 1943. [Class 135] In an automatic pilot including a hydraulic servomotor with a slidable byepass valve which, when opened, interconnects the two sides of the servo-piston to render the latter ineffective, the byepass valve is controlled by a further valve included in a device comprising a manifold with a first chamber provided with an inlet from the pump, an outlet to the servomotor, balanced, oil, control-valve, and an outlet to actuating means for the byepass valve, a second chamber provided with an outlet to' a sump, and a manually-operable valve for opening and closing a passage interconnecting the two chambers. With the diaphragm valve 11 in the open position shown, hydraulic pressure fluid flowing in through pipe 8 -is short-circuited back to the sump through pipe 23. When valve 11 is closed, the pressure fluid is directed through pipes 6, 7 to actuate the servomotor ...

VALVE ASSEMBLY

... 1421037 Valves NORDHYDRAULIC AB 8 Feb 1973 [25 Feb 1972] 6274/73 Heading F2V A valve assembly for controlling a reversible positive-displacement hydraulic motor 11, e.g. for hydraulic cranes, front end loaders and power shovels, comprises a directional control valve 17 associated with supply passages 21, 22, 25, drain passages 19, 20, 26, and transfer passages 23, 24 for directing actuating fluid to and from the motor via ports 28, 30. Moreover, the assembly includes check valves 29, 31, and valves 33, 39 which function as pressure relief anti-cavitation and drain valves. During operation with the pump P supplying pressure fluid to one end 14, 15 of the motor, the pressure differential across ports 28, 30 subjected to a slidable plunger 45 via passages 48, 49 or the pressure differential across passages 23, 24 subjected to the plunger 45 via passages shown in chain lines, causes the plunger to open the appropriate valve 33 or 39 to permit fluid to pass from the other end of the motor to ...

IMPROVEMENTS IN AND RELATING TO CONTROL VALVES

... 1293550 Valves COMMERCIAL SHEARING & STAMPING CO 26 Nov 1969 [4 Aug 1969] 57871/69 Heading F2V A valve of the kind in which movements of a spool 12 selectively connect the ends of double acting motor (not shown) via chambers 15, 16 with either an inlet 100, feeding chambers 17, 18, or an exhaust 65, 73, connected to chambers 13, 14, is characterised by the provision of a spool 50 which is positioned by the pressure differential between chamber 52, connected to inlet 100, and a chamber X which is fed with fluid at outlet pressure. Spool 50 thus effects a variable by-pass flow from inlet 100 to exhaust via chambers 44, 14 and 73, and thereby maintains a constant flow rate to the motor under all loading conditions. Spool 12 is provided with ball check valves 24, 25 which control the flow to chamber X via channels 21, 21a, 49 and 56. The Specification describes in detail the operation of the valve in controlling a pair of hydraulic motors.

FLUID FLOW DIVIDER

CONTROL APPARATUS FOR CONTROLLING THE CONNECTION BETWEEN A PUMP AND A LOAD

Improvements in or relating to control valves for fluid pressure operated mechanisms

... 915,114. Valves. HYDRAULIC UNIT SPECIALTIES CO. March 12, 1959, No. 8660/59. Class 135. A rectangular valve casing 5, Fig. 3, incorporates three parallel bores 12, 13, 14 in a common vertical plane, the two latter housing sliding closure members 16, 17 respectively; the casing has an inlet 19 whilst bore 13 embodies grooves 201, 211 leading to outlets 20, 21, Fig. 4, e.g. connected to a double-acting ram. Another pair of outlets lead to grooves 221, 231, Fig. 3, in the bore 14 to control another similar ram or, if one of the outlets is closed-off, as shown, a single acting ram. The inlet 19, near the top of the casing, communicates directly with an exhaust outlet 26 near the bottom of the casing via a passage 29 from which leads a U-shaped exhaust 35, both limbs 36, 37 of which intersect the bores 12, 13, 14. The bore 13 is also provided with grooves 421, 431 that are interconnected by a U-shaped passage 39, Fig. 4, which is connected ...

AUTOMATIC CHANGE-OVER DEVICE

Improvements brought to the devices hydrolic intended for the alternative displacement of elements for high inertia.

HYDRAULISCHES STEUERVENTIL

HYDRAULIC CONTROL VALVE

IN TWO RELIEF VALVES AN EXHIBITING BLOCK INSERTING OVERLOADING VALVE

HYDRAULIC SERVO ACTUATOR TO SCOLDED FROM COURSES

TRANSFER VALVE.

HYDRAULIC SYSTEM WITH A HYDROMECHANICAL LOCKING MECHANISM FOR THE WORKING POSITION OF A CONTROL VALVE.

HYDROSTATIC TRANSMISSION

Device for the control of Sollwertgebern in devices with a majority of hydraulically operated parts, e.g. excavators

Delay device for hydraulically steered, did not synchronize transmissions of motor vehicles, in particular from catarpillars

Subsea hydraulic control device and a method for producing thereof

The present invention relates to a subsea hydraulic control device (10) for hydraulically controlling a subsea module (2). The control device (10) comprises a hydraulic distribution unit (12) with a valve unit (13) and a manifold unit (50), where hydraulic fluid lines are provided in the valve unit (13) and in the manifold unit (50). The hydraulic distribution unit (12) comprises a low pressure hydraulic input port (21) connectable to a low pressure fluid source (LP) and connected to a low pressure fluid line (22) within the hydraulic distribution unit (12), a high pressure hydraulic input port (31) connectable to a high pressure fluid source (HP) and connected to a high pressure fluid line (32) within the hydraulic distribution unit (12), a return port (41) connectable to a return fluid reservoir (R) and connected to a return fluid line (42) within the hydraulic distribution unit (12) and a number of hydraulic output ports (24, 34) connectable to subsea actuators (A) of the subsea module ...

Hydraulic valve arrangement

Fluid actuator with limit sensors and fluid limit valves

HYDRAULIC FLUID PRESSURE CONTROL

Abstract A hydraulic fluid pressure control system comprising: a hydraulic pump motor having an electrical input configured to receive an AC input signal and a hydraulic fluid 5 output configured to output a pressure proportional to the frequency of the AC input signal; and electronic control circuitry connected to said electrical input, wherein: said electronic control circuitry provides an AC input signal of variable frequency. The electronic control circuitry may comprise an inverter. i~. 7 \..10 Fig. 2 ...

FLOW RATE CONTROL VALVE

FLUID FLOW DIVIDER

POWER TRANSMISSION

POWER TRANSMISSION

HYDRAULIC MAKE-UP VALVE

HYDRAULIC DIRECTIONAL CONTROL VALVE

VALVE BASE WITH INTEGRAL FLOW CONTROLS

A valve base for a fluid-pressure valve system which is provided with integral exhaust flow control valve means which may be selectively mounted in an end of the valve base, or in a side of the valve base, or with an exhaust flow control valve means in an end of the valve base and another exhaust flow control valve means in a side of the valve base.

MAKE-UP VALVE FOR HYDRAULIC CONTROL CIRCUIT

VALVE WITH HYDRAULIC LOCK

POWER TRANSMISSION

HYDRAULIC CONTROL VALVE

PROPORTIONAL PRESSURE CONTROLLER WITH ISOLATION VALVE ASSEMBLY

A proportional pressure controller includes a body having inlet, outlet, and exhaust ports. A fill valve communicates with pressurized fluid in the inlet port. A dump valve communicates with pressurized fluid from the fill valve. An inlet poppet valve opens by pressurized fluid through the fill valve. An exhaust poppet valve when closed isolates pressurized fluid from the exhaust port. An outlet flow passage communicates with pressurized fluid when the inlet poppet valve is open, and communicates with the outlet port and an exhaust/outlet common passage. An isolation valve assembly selectively isolates fluid flow to and from the inlet port or the exhaust port to achieve a zero pressure condition.

VALVE ASSEMBLY WITH INTEGRAL SENSORS

A valve assembly includes an electronics housing (14) and a valve housing assembly (12) engaged to the electronics housing. The valve housing assembly includes a valve body (16) defining a plurality of fluid ports (39) in fluid communication with the valve bore (24). A plurality of fluid dampeners (40) is disposed in the fluid ports. A sensor plate (52) is engaged to the valve body. The sensor plate defines a plurality of sensor ports (76) that are generally aligned with the fluid ports (39) of the valve body. At least four fluid sensors (50) are disposed in the plurality of fluid ports (39) of the valve body. A cover (84) is engaged to the sensor plate (52). The cover defines a cavity. A circuit board (82) is disposed in the cavity of the cover. The circuit board is in electrical communication with the fluid sensors (50).

CONTROL VALVE FOR PRIME MOVER SPEED CONTROL IN HYDRAULIC SYSTEMS

A control valve (10) is provided for mobile or stationary hydraulic equipment for automatically increasing or decreasing speed of a prime mover in response to operation of a hand lever to extend a hydraulic cylinder. A prime mover speed control valve (42) is integrated with a spool (12) in a single housing (10) for the purpose of simultaneously controlling the supply of fluid to a hydraulic cylinder (16) and to a cylinder (61) controlling prime mover speed. When the spool (12) is in the "CYLINDER EXTEND" or "NEUTRAL" position for the implement cylinder, a hydraulic control signal is provided from port (55) to the prime mover control cylinder (61) to signal increased prime over speed and increased output from a hydraulic pump (17). When the spool (12) is in the "CYLINDER RETRACT" position for the implement cylinder (16), the spool (12) blocks the signal from port (55) while allowing fluid to drain from the implement cylinder (16) to a reservoir (29).

Steuereinrichtung für Druckmittelschaltvorrichtungen.

Durch Flüssigkeitsdruck angetriebene Vorrichtung zur Erzielung von Verstellbewegungen.

Valve à trois voies.

Installation de commande à valves pour fluide.

Appareil hydraulique

Steuerventil

Steuervorrichtung an hydraulischen Antrieben

Distributore di un impianto di frenatura pneumatica di un autoveicolo

Einrichtung zur Herabsetzung der Ansprechzeit eines in einem Ventilgehäuse beweglich untergebrachten Kolbenschiebers

Dispositif de commande d'un écoulement de fluide

Sicherheitssteuervorrichtung

Steuergerät

Schaltelement für Kältekompressoren

Mengengeregeltes Wegeventil

Steuervorrichtung für hydraulisch betriebene Einrichtungen

Verzögerungsvorrichtung für hydraulisch gesteuerte, nicht synchronisierte Getriebe von Motorfahrzeugen

Steuerventilblock

Steuerungseinrichtung

Steuervorrichtung für lastunabhängige Durchflussregelung

STEUERGERAET FUER HYDRAULISCHE ARBEITSGERAETE.

Apparecchiatura di entrata con tastiera funzionante a fluido per macchine per l'elaborazione di dati

Anordnung zur Einpassung eines Einbaukühlschrankes in die Einbaunische

Schiebergehäuse für hydraulische Kolbenschiebersteuerungen und Verfahren zu seiner Herstellung

Steuervorrichtung für hydraulisch gesteuerte Anlagen

Dispositif d'amplification de pression

Valve copieuse hydraulique par machine-outil

Hydraulic system for working machine

A pair of dozer control valves V 3, V 6 concurrently operable; a pilot pressure valve V 14 switchable between an independent position 27 where, when only track devices 5 are operated, discharged fluid from one hydraulic-fluid discharge port P 1 is independently supplied to one track control valve and one dozer control valve, and discharged fluid from the other hydraulic-fluid discharge port P 2 is independently supplied to the other track control valve and the other dozer control valve, and a merging position 28 where, when the other control valves are operated, discharged fluid from the one hydraulic-fluid discharge port and from the other hydraulic-fluid discharge port are merged and supplied to the control valves V 1 to 10; and pressure compensation valves V 11 in the control valves and for distributing hydraulic fluid at flow rates based on extent of actuation of the other control valves operated, irrespective of the magnitude of the loads.

Hydraulic valve with pressure limiter

An assembly of valve sections 10 includes an inlet section 12 , an outlet section 14 , a working section 16 , and a working section 18 . The working section 16 is a conventional pressure compensated working section. The working section 18 includes a directional control valve 21 , a pressure compensator valve 50 , and a pressure limiter valve 52 . The valves 50 and 52 are of integral construction, such that each is an essential part to complete the other. The pressure compensator valve 50 includes a pressure compensator spool 60 movable between an opened position (FIGS. 2 and 5 ) and a closed position (FIGS. 4 and 6 ) in response to a pressure differential across the spool. The pressure limiter valve 52 includes a pressure limiter spool 76 that moves to an open position to change the pressure differential and close the pressure compensator valve when a selected limit pressure is reached.

Time delay valve

An on-off valve ( 7 ) opens/closes flow between a port (P) where compressed air is supplied and a port (A) connected to the outside; and a delay mechanism ( 8 ) which opens the on-off valve ( 7 ) after a predetermined period of time. The delay mechanism ( 8 ) includes: a throttle valve ( 22 ); a piston ( 36 ); a pressurizing chamber ( 40 ); and a communicating passage ( 42 ). When a pressure of the compressed air supplied from the first port (P) to the pressurizing chamber ( 40 ) reaches a set pressure, a valve opening force exerted on the piston ( 36 ) exceeds a valve closing force exerted on the on-off valve ( 7 ), and the on-off valve ( 7 ) is opened, so that compressed air from the first port (P) is supplied to the outside through the second port (A).

SELECTABLE FLOW DIVIDER DRIVE SYSTEM

A selectable flow divider drive system includes a hydraulic fluid reservoir and a plurality of drive motors in fluid communication with the hydraulic fluid reservoir. A hydraulic pump is connected between the hydraulic fluid reservoir and the plurality of drive motors and directs hydraulic fluid from the hydraulic fluid reservoir to the plurality of motors. The hydraulic pump is operable in a high flow condition and a low flow condition. A flow divider component is interposed between the hydraulic pump and the plurality of motors. The flow divider component selectively divides hydraulic fluid flow to each of the plurality of drive motors, where a flow divider of the flow divider component is sized for the low flow condition of the hydraulic pump. A bypass valve is disposed upstream of the flow divider that selectively bypasses the flow divider when the hydraulic pump is operated in the high flow condition. 1. A selectable flow divider drive system comprising:a hydraulic fluid reservoir;a plurality of drive motors in fluid communication with the hydraulic fluid reservoir;a hydraulic pump connected between the hydraulic fluid reservoir and the plurality of drive motors, the hydraulic pump directing hydraulic fluid from the hydraulic fluid reservoir to the plurality of motors, wherein the hydraulic pump is operable in a high flow condition and a low flow condition;a flow divider component interposed between the hydraulic pump and the plurality of motors, the flow divider component selectively dividing hydraulic fluid flow to each of the plurality of drive motors, wherein a flow divider of the flow divider component is sized for the low flow condition of the hydraulic pump; anda bypass valve disposed upstream of the flow divider, the bypass valve selectively bypassing the flow divider when the hydraulic pump is operated in the high flow condition.2. A selectable flow divider drive system according to claim 1 , further comprising a bypass solenoid valve in fluid ...

Fluid container having plurality of chambers, valves, and air bag assembly

A fluid container includes a housing unit including a free-fluid chamber, a regulated chamber, and a plurality of valves. The free-fluid chamber is configured to store fluid. The regulated chamber includes an air bag assembly, an outlet, and a plurality of states. The air bag assembly is configured to regulate respective fluid therein and includes at least one air bag including an internal chamber having a volume capacity. The outlet is configured to transport the respective fluid from the regulated chamber. At least one of the plurality of valves is configured to selectively stop fluid communication between the regulated chamber and the free-fluid chamber based on the respective state of the regulated chamber.

FLUID FLOW PATH CONTROL UNIT FOR VEHICLE DRIVE SYSTEM

A fluid flow path control unit includes a fluid supply unit supplying fluid to a hydraulic connection/disconnection unit and a fluid supplied portion, and a flow path selector valve disposed on a fluid flow path between the fluid supply unit and the fluid supplied portion or stradding between a hydraulic path communicating between the fluid supply unit and the hydraulic connection/disconnection unit and the fluid flow path. The selector valve includes a valve element switchable between a first operating position and a second operating position, a restoration member biasing the valve element from the second position toward the first position and a fluid chamber accomodating fluid biasing the valve element from the first position toward the second position. The fluid flow path has a flow path resistance differing between when the valve element is in the first position and when the valve element is in the second position. 1. A fluid flow path control unit for a vehicle drive system , the vehicle drive system including:a motor that generates driving force to drive a vehicle;a hydraulic connection/disconnection unit that is provided on a power transmission line defined between the motor and a wheel that connects and disconnects the transmission of power therebetween; anda fluid supplied portion that is at least one of the motor and the power transmission line and to which fluid that is used for cooling or lubrication is supplied, the fluid flow path control unit including:a fluid supply unit that supplies fluid to the hydraulic connection/disconnection unit and the fluid supplied portion; anda flow path selector valve that is disposed on a fluid flow path that establishes a communication between the fluid supply unit and the fluid supplied portion or is disposed so as to straddle between a hydraulic path that establishes a communication between the fluid supply unit and the hydraulic connection/disconnection unit and the fluid flow path, a valve element that is ...

Flow control valve for construction machine

A flow control valve for a construction machine is provided, which can constantly control a flow rate of hydraulic fluid supplied to a hydraulic actuator through a flow control spool in a spool. The flow control valve for a construction machine, having a valve body in which a supply passage communicating with a pump passage and actuator ports connected to a hydraulic actuator are formed, and a spool installed in the valve body to be shifted, includes a flow control spool shifted in the spool to variably control a cross-sectional area of a passage connected to the one actuator port if a flow rate of the hydraulic fluid that flows through the supply passage is higher than a set flow rate, a first passage formed on the spool to communicate with the supply passage and a second passage formed on the spool to communication with the one actuator port and having a cross-sectional area that is varied depending on the shifting of the flow control spool.

ELECTRO-HYDRAULIC PILOT OPERATED RELIEF VALVE

Provided is a method of and valve assembly for dumping excess fluid during retraction of a cylinder actuator. The method includes pumping fluid with a pump from a piston side of the cylinder to a rod side of the cylinder; opening a first check valve with relatively high pressure fluid from a downstream side of the pump to allow flow into the rod side of the cylinder; and opening an extend relief valve via a first spool with fluid from the downstream side of the pump to allow excess fluid at an upstream side of the pump to return to a reservoir at relatively low pressure. 1. A valve assembly for releasing excess fluid to a reservoir at low pressure comprising:a first spool moveable in a first bore in a valve body having a first side and a second side;a first check valve disposed in the first side of the first bore;an extend relief valve disposed in the second side of the first bore;a second spool moveable in a second bore in the valve body having a first side and a second side; anda second check valve disposed in the second side of the second bore,wherein the first spool is configured to press against and thereby open the first check valve when the first spool is energized by relatively high pressure fluid in the second side of the bore, and is further configured to press against and thereby open the extend relief valve when the first spool is energized by relatively high pressure fluid on the first side, thereby allowing relatively low pressure fluid to flow through the extend relief valve, andwherein the second spool is configured to press against and thereby open the second check valve when the second spool is energized by relatively high pressure fluid in the first side of the second spool.2. The valve assembly of wherein the first check valve has a flow side and a block side and is configured to open when relatively high pressure fluid impinges on the flow side.3. The valve assembly of wherein the extend relief valve has a flow side and a block side and is ...

Compressed air single-action actuator

A compressed air single-action actuator includes an actuator body, a solenoid valve is provided in the actuator body, a solenoid valve plate is provided between the actuator body and the solenoid valve, a gas chamber is provided on the side face of the actuator body, an O-ring seal is provided between the gas chamber and the actuator body; a first inlet passage communicated with the gas chamber is provided on the actuator body, a check valve is provided at one end of the gas chamber of the first gas inlet passage, the other end of the outlet is provided at a right back side of the Namur interface; a second gas inlet passage is provided on the actuator body communicated with the gas chamber, the outlet of the second gas inlet passage is provided at an upper left side of the Namur interface. 1. A compressed gas single-acting actuator , comprises an actuator body , wherein pistons are respectively provided on left and right ends of said actuator body , a rack is provided on each of said pistons , a central axle is provided between said two racks , a plurality of reset springs are provided between said pistons and said actuator body , an internal cavity is formed between said pistons , an external cavity is formed between said pistons and said actuator body , an external cavity gas chamber path communicated with said external cavity is provided on said actuator body , wherein a solenoid valve is provided on a Namur interface of said actuator body , a solenoid valve plate is provided between said Namur interface and said solenoid valve , a gas chamber is provided on said actuator body , a ring seal is provided between said gas chamber and said actuator body; a first gas inlet passage communicated with said gas chamber is provided on said actuator body , a check valve is provided at a first end of said gas chamber of said first gas inlet passage , and a second end of said outlet is provided at a right back side of said Namur interface for corresponding to a second gas ...

Relief Pressure Control Device for Hydraulic Work Machine

A relief pressure control system is provided with a controller for outputting, responsive to an adjustment signal output from a dial switch, a control signal to control a relief pressure of a variable solenoid relief valve, a display unit for displaying, responsive to display signals outputted from the controller, a relationship between a circuit pressure output from a pressure sensor and a pressure required by a hydraulic cylinder, and a control device constituting a start instruction unit for instructing a start of control of the variable solenoid relief valve. Stop valves are arranged in sections of main lines, which communicate a directional control valve and the hydraulic cylinder with each other, to open or close the section. The sections are located between positions on the main lines, where the variable solenoid relief valves are connected to the main lines, respectively, and the hydraulic cylinder.

HYDRAULIC PUMP FOR CONSTRUCTION MACHINERY

Disclosed is a hydraulic pump for construction machinery for controlling to inhibit one-way driving when compound-operating two-way driving and work devices, such as a boom, to enhance operation efficiency. The hydraulic system for the construction machinery of the present invention provides the hydraulic system comprising: an operation device for driving and an operation lever for the work devices; a left driving motor which connects to a first hydraulic pump; a first control valve which is installed on the discharge flow path of the first hydraulic pump; a right driving motor which is connected to a second hydraulic pump; a hydraulic actuator which is connected to the first hydraulic pump and the second hydraulic pump; a second control valve which is installed on the discharge flow path of the first hydraulic pump or the second hydraulic pump; a third control valve which is installed on a flow path that branches from the discharge flow path of the second flow path; a first bypass valve which is connected to the upstream portion of the discharge flow path of the first hydraulic pump; a second bypass valve which is connected to the upstream portion of the discharge flow path of the second hydraulic pump; a confluence valve which is installed on a flow path which connects in parallel the discharge paths of the first and second hydraulic pumps; and a controller for controlling the opening of the first and second bypass valves and the confluence valve according to an operation signal that is input from the operation device for driving and the operation lever for the work device. 1. A hydraulic system for a construction machine comprising:a manipulation device for traveling and a manipulation lever for a work apparatus that are configured to output manipulation signals in proportion to a manipulation amount;first and second hydraulic pumps;a left traveling motor connected to the first hydraulic pump and driven by the manipulation of a manipulation device for left ...

Compressed Air Supply Installation, Pneumatic System and Method for Operating a Pneumatic Installation

The invention relates to a compressed air supply installation () for operating a pneumatic installation (), especially an air suspension installation of a vehicle, comprising a compressed air supply unit (), a compressed air port () towards the pneumatic installation (), a venting port () towards the surroundings, a first pneumatic connection between the compressed air supply () and the compressed air port (), said pneumatic connection having an air drier () and a shut-off valve, and a second pneumatic connection between the compressed air port () and the venting port (). According to the invention, the shut-off valve is designed as a pneumatically pilot-controlled check valve (). 3607052. The compressed air supply installation as claimed in or , characterized in that the main pneumatic line () and the vent line () are connected as separate lines to a common compressed air feed port ().4636460612. The compressed air supply installation as claimed in one of to , characterized in that the pilot-operated nonreturn valve ( , ) is arranged in the main pneumatic line () between the air dryer () and the compressed air port ().560626363. The compressed air supply installation as claimed in one of to , characterized in that the main pneumatic line () has a restrictor () and the pilot-operated nonreturn valve () in a pneumatic series circuit , or the pilot-operated nonreturn valve is in the form of a throttle check valve (′) that can be released.6. The compressed air supply installation as claimed in one of to , further having:{'b': '74', 'a control valve (),'}{'b': 110', '60', '74, 'a pneumatic control line () between the main pneumatic line () and the control valve (), wherein'}{'b': 63', '64', '74', '60', '110, 'the pilot-operated nonreturn valve (, ) can be released by means of the control valve (), using a pressure derived from the main pneumatic line () via the pneumatic control line ().'}86406373640641680. The compressed air supply installation as claimed in one of to ...

Valve assembly, in particular for use in pneumatic networks

A valve assembly for use in a pneumatic network, includes a body having a first inlet port and a first air discharge port. A main duct includes a convergent portion, a restricted-section portion having a variable area of passage, and a divergent portion. An actuator assembly includes an intake volume and a second inlet port in fluid communication with the intake volume by valve means provided for enabling intake of a second fluid flow through the second inlet port and towards the intake volume, wherein the second fluid flow is drained off through the first discharge port together with the first fluid flow.

Hydraulic System and Arrangement for an Access Arrangement

A hydraulic system for an access arrangement having a platform configured for movement between a deployed position and a stowed position, the hydraulic system including: at least one hydraulic power unit configured to urge hydraulic fluid through a hydraulic circuit; at least one hydraulic cylinder directly or indirectly connected to a portion of the platform and configured to urge the platform towards at least one of the stowed position and the deployed position, wherein the at least one hydraulic cylinder is in fluid communication with the hydraulic power unit; and a pressure regulating valve in a path between the at least one hydraulic power unit and the at least one hydraulic cylinder, wherein the pressure regulating valve is operable to prevent the at least one hydraulic cylinder from urging the platform to the stowed position if a load on the platform exceeds a specified threshold.

SOLAR GENERATOR AND HYDRAULIC CONTROL SEAT VALVE

In a solar generator, comprising a reflector and an electrohydraulic sun-position tracking device with at least one hydraulic cylinder and a hydraulic control seat valve, the reflector can be guided via the control seat valve to follow in synchronism with the course of the sun continuously and uninterruptedly. The control seat valve for regulating a pressure medium flow permanently supplied to the hydraulic cylinder comprises a seat surface and a sealing surface permanently pressed against each other with variable contact pressure, with which the pressure medium flow can be generated as controlled leakage. The sealing surface is made of a material that can be deformed by contact pressure. In the control seat valve, the controlled leakage is set in a control position at least substantially without lifting movement exclusively by the relative material deformation of the sealing surface on the seat surface, which deformation is set via the contact pressure. 1. A solar generator comprising:a reflector; andan electrohydraulic sun-position tracking device which is used for the reflector and comprises a hydraulic cylinder and a control seat valve provided between at least one working line of the hydraulic cylinder and a pressure source, the control seat valve including a seat portion that comprises a seat surface and a sealing surface which are permanently adjacent to each other by variable contact pressure without a lifting stroke to supply a regulated pressure medium flow to the hydraulic cylinder, and between which the pressure medium flow can be generated as controlled leakage, the sealing surface being made of a material that can be deformed by contact pressure;wherein the reflector can be guided via the control seat valve to follow in synchronism with the course of the sun continuously and uninterruptedly.2. The solar generator according to wherein the tracking device further includes a solenoid magnet for pressing on the sealing surface at least substantially ...

LIFTING SYSTEM AND LIFTING METHOD FOR JIB OF AN OPERATING MACHINE, AND AN OPERATING MACHINE THEREOF

A lifting system for a jib of an operating machine that includes an energy storage device having an energy storage cylinder and an accumulator, the energy storage cylinder having an upper chamber, a lower chamber, and an energy storage piston rod connected to the jib. The upper part of the accumulator is filled with gas, and the lower part of the accumulator is filled with hydraulic oil and communicates with the lower chamber of the energy storage cylinder. The lifting system also includes a hydraulic pump and a control cylinder for controlling the lifting of the jib, which comprises an upper chamber, a lower chamber, and a control piston rod connected to the jib. 1. A lifting system for a jib of an operating machine , comprising:an energy storage device used for storing the gravitational potential energy during the descending of the jib and lifting the jib by use of the stored energy during the ascending of the jib, the energy storage device includes an energy storage cylinder and an accumulator, the energy storage cylinder comprising an upper chamber and a lower chamber which are separated by an energy storage piston, wherein the energy storage piston comprises an energy storage piston rod operably connected to the jib, wherein an upper volume of the accumulator is filled with a pressurized gas, and a lower volume of the accumulator is filled with a pressurized hydraulic oil and is in fluid communication with the lower chamber of the energy storage cylinder;a control cylinder for controlling the jib lifting, the control cylinder comprising an upper chamber and a lower chamber which are separated by a control piston, wherein the energy storage piston comprises a control piston rod operably connected to the jib; anda hydraulic pump for selectively supplying the pressurized hydraulic oil to the upper chamber of the control cylinder or the lower chamber of the control cylinder through a distributor; wherein when the hydraulic pump supplies the pressurized hydraulic ...

ELECTRO-HYDRAULIC SYSTEM FOR CONTROLLING MULTIPLE FUNCTIONS

Electro-hydraulic systems ( and ) control multiple hydraulic motors without objectionable erratic or jerky motion. The system () includes a variable displacement pump (), an electronic controller (), a direction control valve (), first and second pump outlet valves () and (), and a fluid reservoir (). The pump () does not require or use a load feedback signal to control pump output. The controller () provides electric control signals to a pump control () and to individual hydraulic motors (). A load sense circuit () resolves a highest load sense pressure Ps, which is communicated to the first and second pump outlet valves () and (). The first pump outlet valve () limits the maximum load sense pressure. The second pump outlet valve () limits the maximum pressure differential between the pump outlet and the load sense pressure. 2. (canceled)3. An electro-hydraulic system as set forth in claim 2 , wherein the value of Pis set to be greater than the value of Pand less than the sum of P4. An electro-hydraulic system as set forth in claim 3 , wherein each pump outlet valve discharges hydraulic fluid from the pump outlet to the reservoir.5. An electro-hydraulic system as set forth in claim 1 , wherein the hydraulic pump is a variable displacement pump having a pressure limiting device set to a pump outlet pressure limit value P claim 1 , the hydraulic motors each provide a load sense signal to a logic circuit claim 1 , the logic circuit communicates the highest load sense pressure of the hydraulic motors to the pump outlet valve claim 1 , the pump outlet valve limits the maximum load sense pressure to a pressure limit value P claim 1 , and the value Pis smaller than the value P.6. An electro-hydraulic system as set forth in claim 1 , wherein the hydraulic pump is a variable displacement pump having a pressure limiting device set to a pump outlet pressure limit value P claim 1 , the hydraulic motors each provide a toad sense signal to a logic circuit claim 1 , the logic ...

CONTROL DEVICE OF POWER TRANSMISSION DEVICE

By a control processing of the sliding-mode control using a switching function configured from a first variable component, which is a deviation between an observed value and a desired value of a secondary power imparted to a secondary element () from a primary element () via an elastic deformation member (), and a second variable component which is a temporal change rate of the deviation, so as to sequentially determine a control input to control an actuator () to converge the first variable component to zero on a switching hyperplane. A gradient of the switching hyperplane is set such that a time constant corresponding to the gradient of the switching hyperplane is equal to or larger than a given specific time constant. 1. A control device of a power transmission device equipped with a primary element which displaces by a driving power of an actuator , and a secondary element coupled to the primary element via an elastic deformation member capable of deforming elastically , and which is provided so as to relatively displace with respect to the primary element by the elastic deformation of the elastic deformation member , and to receive a power transmission from the primary element via the elastic deformation member , the control device controlling a secondary power as a power applied to the secondary element by the power transmission to a desired value:wherein the elastic deformation member is a member configured such that an elastic deformation coefficient expressing a rate of change of a generated elastic force of the elastic deformation member with respect to a change in a deformation amount thereof, becomes constant;wherein the control device comprisesa control input determining unit configured to sequentially determine a control input for controlling the driving force of the actuator, with a control processing of a sliding-mode control using a switching function configured taking a deviation between an observed value and the desired value of the secondary ...

AIRCRAFT STORE EJECTOR SYSTEM

An aircraft store ejector systems and subsystems thereof. Embodiments can include a two-reservoir re-pressurization system wherein a remote reservoir is used to maintain desired pressure in a local ejector reservoir. The system can include a release valve having a vent valve and valve piston. The release valve can control release of pressurized gas to a pitch control valve. The pitch control valve can be configured to distribute the pressurized gas between two or more ejector piston assemblies. One or more of the ejector piston assemblies can include multiple concentric piston stages and piston chambers, the piston chambers configured to contain a volume of gas. The ejector piston assemblies can be configured to compress the volume of gas within the piston chambers as the piston stages are extended out from the aircraft. Such compression can provide a return force to the piston stages. 1. An aircraft store ejector system , comprising:a pressurized gas arrangement comprising a remote reservoir and a local ejector reservoir, wherein the remote reservoir has a larger volume than the ejector reservoir and is arranged to supply pressurized gas to the ejector reservoir, a pressure regulation arrangement positioned between the remote reservoir and the ejector reservoir that adjusts a pressure level of the pressurized gas supplied from the remote reservoir to the ejector reservoir;a release valve arrangement comprising a vent valve configured to provide selective fluid communication between the ambient surroundings of the release valve arrangement and one or more ejector passages, a main valve configured to provide selective fluid communication between the ejector reservoir and the one or more ejector passages, and a firing valve, wherein opening of the firing valve closes the vent valve and then opens the main valve, and wherein opening the main valve provides pressurized gas to the ejector passages;an ejection system configured to receive a flow of pressurized gas from ...

METHOD AND SYSTEM FOR COMPENSATION OF AN INSUFFICIENT PRESSURE BUILDUP IN THE BRAKING SYSTEM OF A VEHICLE

A method is described for compensation of an insufficient pressure buildup in the braking system of a vehicle in the event of a failure or malfunction of a brake booster for brake force support when an actuating element of the braking system is actuated, the compensation occurring with the aid of a unit for an additional pressure buildup in the braking system and triggering of this compensation occurring as a function of a position of the actuating element in its adjustment travel. An instantaneous position of the actuating element in the adjustment travel is ascertained continuously or periodically, and the triggering and the additional pressure build-up occur as a function of this ascertained instantaneous position. Also described is a corresponding compensating system. 111.-. (canceled)12. A method for compensating an insufficient pressure buildup in a braking system of a motor vehicle , comprising:performing a compensation with the aid of a unit to achieve an additional pressure buildup in the braking system;triggering of the compensation as a function of a position of an actuating element in an adjustment travel of the actuating element; andone of continuously and periodically ascertaining an instantaneous position of the actuating element in the adjustment travel, wherein the triggering and the additional pressure buildup occur as a function of the ascertained instantaneous position.13. The method as recited in claim 12 , wherein the motor vehicle is a motor vehicle in the event of one of a failure and a malfunction of a brake booster for a brake force support during an actuation of the actuating element of the braking system.14. The method as recited in claim 12 , wherein the compensation is triggered when the instantaneous position one of reaches and exceeds a predefinable triggering position in the adjustment travel.15. The method as recited in claim 12 , wherein the compensation occurs by a vehicle dynamics control system of a driver assistant system of ...

Braking System For a Dual Landing Gear Aircraft

A braking system for use with a dual landing gear aircraft. The braking system pairs outboard brake control into an outboard brake system control unit (BSCU) and inboard brake control into a second inboard brake system control unit (BSCU). Each BSCU is designed with two independent control lanes in which the forward wheel set is paired in one control lane and the aft wheels are paired onto the other. Alternate braking is provided via an alternate brake module installed in a fore-aft wheel pairing.

HYDRAULIC PUMP ASSEMBLY FOR A VEHICLE

A hydraulic pump assembly for a vehicle is provided, comprising an electrical motor, a hydraulic pump driven by the electrical motor, and a centrifugal regulator connected with a pressure overflow valve connected to the oil outlet of the hydraulic pump, characterized in that the pump assembly further comprises at least two input check valves and at least two output check valves arranged such that a first pressure outlet port is formed when the motor is rotating in a first direction, and a second pressure outlet port is formed when the motor is rotating in an opposite direction. 1. A hydraulic pump assembly for a vehicle , comprisingan electrical motor, a hydraulic pump driven by the electrical motor, and a centrifugal regulator in connection with a pressure overflow valve connected to the oil outlet of the hydraulic pump,wherein the pump assembly further comprises at least two input check valves and at least two output check valves arranged such that a first pressure outlet port is formed when the motor is rotating in a first direction, and a second pressure outlet port is formed when the motor is rotating in an opposite direction.2. The hydraulic pump assembly according to claim 1 , wherein an output check valve is arranged between each pressure outlet port and the pressure overflow valve.3. The hydraulic pump assembly according to claim 1 , wherein one of the input check valves is arranged on a first suction side of the pump when the motor is rotating in a first direction claim 1 , and wherein the other input check valve is arranged on the other suction side of the pump when the motor is rotating in an opposite direction.4. A hydraulic actuator claim 1 , comprising a hydraulic pump assembly according to claim 1 , and a first coupling connected to the first pressure outlet port claim 1 , and a second coupling connected to the second pressure outlet port.5. A hydraulic actuator claim 1 , comprising a hydraulic pump assembly according to claim 1 , and a piston claim ...

Electronic Control of Actuator Force and Torque with an Independent Metering Valve

A hydraulic system includes one or more sensors configured to measure a pressure at least one input or end of a hydraulic actuation device, such as a cylinder for example. A control module can be operatively coupled to the sensors and at least one metering valve. The control module can selectively open the metering valve when the pressure at one of the ends of the cylinder reaches a first pressure threshold to control the force on the cylinder rod, to permit flow from the end of the cylinder to the tank. 1. A hydraulic system comprising:a cylinder having a first end and a second end opposite the first end, the cylinder being movable between a retracted position and an extended position;a hydraulic pump hydraulically connected to at least the first end of the cylinder to facilitate movement of the cylinder;a first mechanical relief valve hydraulically connected to the first end of the cylinder;a first valve hydraulically connected to the first end of the cylinder and a tank;a first sensor configured to measure a pressure at the first end of the cylinder; anda control module operatively coupled to the first sensor and the first valve, the control module being configured to selectively open the first valve when the pressure at the first end of the cylinder reaches a first pressure threshold, to permit fluid to flow from the first end of the cylinder to the tank.2. The hydraulic system of claim 1 , wherein the first mechanical relief valve is configured to open when the pressure at the first end of the cylinder reaches a second pressure threshold claim 1 , to permit fluid to flow from the first end of the cylinder to the tank claim 1 , the second pressure threshold being greater than the first pressure threshold.3. The hydraulic system of claim 1 , wherein the control module is configured to determine the first pressure threshold based on whether the first end is a rod-end or a head-end.4. The hydraulic system of claim 1 , further comprising:a second valve hydraulically ...

Lifting Mechanism Suspension and Lifting Mechanism

A hydraulic lifting mechanism suspension has a main valve in the activation position whereof at least one hydraulic accumulator is connected to a connection line of the lifting mechanism suspension acting in the lifting direction or to working line of the lifting mechanism suspension acting in the lifting direction. The lifting mechanism suspension is deactivated via a deactivation position of the main valve, while at the same time a connection for recharging or filling the hydraulic accumulator is opened. 1. A lifting mechanism suspension for a lifting mechanism , the lifting mechanism suspension comprising:a main valve having an activation position in which a hydraulic accumulator or an accumulator line connected to an accumulator is connected to a first connection line that acts in a lifting direction, while a second connection line acting in a lowering direction is connected to a tank line, and a deactivation position in which the first and second connection lines and the tank line are disconnected from one another, while the hydraulic accumulator or the accumulator line is configured to be connected to a pressure medium source via a fifth connection of the main valve.2. The lifting mechanism suspension according to claim 1 , wherein the pressure medium source includes a variable displacement pump that supplies at least one lifting mechanism.3. The lifting mechanism suspension according to claim 1 , wherein:the pressure medium source is connected to the fifth connection of the main valve via a pump line, andone of the pump line and the accumulator line is secured via an adjustable pressure-limiting valve.4. The lifting mechanism suspension according to claim 1 , further comprising:a filler valve which creates a 2-way flow regulator with a throttle, the filler valve arranged between the pressure medium source and the fifth connection.5. The lifting mechanism suspension according to claim 1 , further comprising:an activation valve configured to connect the ...

BOOM POTENTIAL ENERGY RECOVERY OF HYDRAULIC EXCAVATOR

A hydraulic system for recovering potential energy of a load implement of a mobile construction vehicle. The hydraulic system includes first and second actuators and control valving. The first and second actuators are configured to be coupled to the load implement for controlling raising and lowering of the load element. The control valving is operable between a first position at which, during a lowering of the load implement, the control valving directs hydraulic fluid from one of the first and second actuators to an accumulator to charge the accumulator, and a second position at which the control valving directs hydraulic fluid from the accumulator to one or more of the first and second actuators to power the one or more of the first and second actuators to raise the load element. 128-. (canceled)29. A hydraulic system comprising:a first actuator system comprising a first actuator, a first plurality of hydraulic logic elements, and a first proportional valve;a second actuator system comprising a second actuator, a second plurality of hydraulic logic elements, and a second proportional valve;a pump selectively fluidly connectable to the first actuator system through the first proportional valve and selectively fluidly connectable to the second actuator system through the second proportional valve;wherein the first plurality of logic elements control the directionality of a hydraulic fluid between the pump and the first actuator; andwherein the second plurality of logic elements control the directionality of the hydraulic fluid between the pump and the second actuator.3037-. (canceled)38. The hydraulic system of claim 29 , wherein the first actuator includes a cylinder for a load implement and the second actuator includes a motor for a swing drive.39. The hydraulic system of claim 29 , wherein the pump includes a pressure sensor claim 29 , and each actuator is configured to operate at a speed controlled based on the pressure sensed by the pressure sensor.40. The ...

SPEED CONTROLLER

A speed controller is capable of being applied to a cylinder with a short stroke with a simple structure. The speed controller includes a first flow channel and a second flow channel allowing a first port and a second port to communicate with each other, into which pressure fluid is allowed to flow, in which a first valve is arranged in the first flow channel, a second valve is arranged in the second flow channel, a third flow channel and a fourth flow channel are further included, and a third valve is arranged in the third flow channel, allowing only flowing from the first port toward a portion on the piston shaft side with respect to a piston in a cylinder chamber in the third flow channel as well as closing the first flow channel and the fourth flow channel by moving a third valve body in a direction of opening the third flow channel, and opening the first flow channel and the fourth flow channel by moving the third valve body in a direction of closing the third flow channel. 14-. (canceled)5. A speed controller comprising:a first flow channel and a second flow channel allowing a first port and a second port respectively arranged in a body part to communicate with each other, into which pressure fluid is allowed to flow,wherein a first valve is arranged in the first flow channel, regulating a flow rate of flowing pressure fluid by allowing a first valve body arranged on a side where a piston shaft fixed to a piston arranged so as to reciprocate in a cylinder chamber formed in the body part as well as protruding to the outside of the cylinder chamber protrudes to the outside of the cylinder chamber to contact or be separated from a first opening hole formed in the body part,a second valve allowing only flowing from the first port toward the second port is arranged in the second flow channel,a third flow channel allowing the first port to communicate with a portion on a piston shaft side with respect to the piston in the cylinder chamber, into which pressure fluid ...

Distributor block for air distribution in pneumatic systems of commercial vehicles

An air distributor block in pneumatic systems of utility vehicles has at least two modules with a body joined together, at least one mounting hole, at least one through-hole, at least one fastening element and seals placed between the modules is characterized by the fact that it comprises two outer modules: the upper module and the lower module equipped with a central coaxial blind hole with the identical hole in the other modules, and each outer module has at least two mounting through-holes parallel to the central axis of the module, in which bolts are mounted, which protrude above the outer modules, terminated on each side with a threaded tip for connecting to the vehicle frame, where in two opposite side walls of each outer module sockets are made with embedded connector elements or sockets equipped with blinding plugs. 1. An air distributor for pneumatic systems of utility vehicles comprising at least two modules with a body joined together , at least one mounting hole , at least one through hole , at least one fastening element and seals placed between the modules with two external modules:a top module and a bottom module equipped with a central coaxial blind hole with an identically sized hole in other modules,wherein each external module has at least two mounting through-holes parallel to a central axis of the external module, in which bolts are mounted which protrude above the external modules, terminated on each side with a threaded end adapted for connecting to the vehicle frame,and wherein in two opposite side walls of each external module sockets are made with embedded connectors or blinding plugs in an upper wall of the external bottom module and the lower wall of the external top module where there are two recesses equipped with three through holes with sockets made along an edge of each side wall, engaging with a locking element equipped with a crossbeam with embedded three vertical bottom projecting pins and three vertical top projecting pins,and ...

WORKING MACHINE CONTROL SYSTEM

A working machine control system includes: a split-flow fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port; a communication switching valve configured to be switched by a switch signal when any one of a first operation valve and a second operation valve is switched so as to allow a first neutral passage and a second neutral passage to communicate with each other; a neutral cut valve configured to be switched by the switch signal so as to block communication between a tank and one of the first neutral passage and the second neutral passage for the first operation valve or the second operation valve that is not switched; and a discharge flow rate adjusting device configured to adjust the fluid pressure pump so as to reduce a discharge flow rate thereof when the switch signal is inputted from any one of the first operation valve and the second operation valve. 1. A working machine control system configured to control a working machine including a first actuator and a second actuator , the working machine control system comprising:a split-flow fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port;a first circuit system to which the working fluid discharged from the first discharge port is supplied, the first circuit system including a first operation valve and a first neutral passage, the first operation valve being configured to control the first actuator, the first neutral passage allowing the first discharge port to communicate with a tank in a state where the first operation valve is placed at a normal position;a second circuit system to which the working fluid discharged from the second discharge port is supplied, the second circuit system including a second operation valve and a second neutral passage, the second operation valve being configured to control the second actuator, the second neutral passage allowing the second discharge port ...

CONTROL SYSTEM FOR A FELLING SAW AND METHOD OF CONTROL THEREOF

A system for controlling a felling saw in a forestry machine, the felling saw being driven by a hydraulic pump and saw motor circuit. The system includes an instrument for measuring a rotational speed of the felling saw and generating a signal indicative of the rotational speed, a calculator for calculating a power consumption of the hydraulic pump and saw motor circuit adjusted as a function of the signal indicative of said rotational speed, and a controller for adjusting hydraulic settings of the hydraulic pump or/and saw motor circuit based on the calculated power consumption. A method for controlling the felling saw is also disclosed. 1. A system for controlling a felling saw in a forestry machine , the felling saw being driven by a hydraulic pump and saw motor circuit , the system comprising:an instrument for measuring a rotational speed of the felling saw and generating a signal indicative of said rotational speed;a calculator for calculating a power consumption of the saw motor circuit and an adjusted power requirement for the hydraulic pump and saw motor circuit, the power requirement being adjusted as a function of the signal indicative of said rotational speed; anda controller for adjusting hydraulic settings of the hydraulic pump and saw motor circuit based on the calculated adjusted power requirement.2. The system according to claim 1 , wherein the saw motor is an electrically controlled variable displacement saw motor.3. The system according to claim 1 , wherein the hydraulic pump is an electrically controlled variable flow pump.4. The system according to claim 1 , wherein the hydraulic pump is an electrically controlled hydrostatic variable flow pump.5. The system according to claim 1 , wherein the hydraulic pump is a pressure compensated controlled variable flow pump.6. The system according to claim 1 , further comprising a memory for keeping in memory the signal indicative of said rotational speed.7. A method for controlling a felling saw in a ...

HYDRAULIC DEVICE AND PRIME MOVER DEVICE

An object of the present invention is to prevent breakage of a unidirectional filter part for high-pressure oil. A hydraulic device supplies oil to a high-pressure oil channel L and a low-pressure oil channel L from an oil tank via a supply pump The hydraulic device includes an accumulator capable of accumulating a hydraulic pressure of the oil supplied to the high-pressure oil channel from the supply pump; a filter part disposed between the supply pump and a connection point N at which the high-pressure oil channel connects to the accumulator, along a direction in which the oil is supplied; and a check valve capable of preventing a backflow of the oil to the filter part, and disposed between the filter part and the connection point. 1. A hydraulic device configured to supply oil to a high-pressure oil channel and a low-pressure oil channel from an oil tank via a supply pump which supplies the oil to both of the high-pressure oil channel and the low-pressure oil channel , the hydraulic device comprisingan accumulator capable of accumulating a hydraulic pressure of the oil supplied to the high-pressure oil channel from the supply pump, a filter part disposed between the supply pump and a connection point at which the high-pressure oil channel connects to the accumulator, along a direction in which the oil is supplied; and', 'a check valve which prevents breakage of the filter part, the check valve being disposed between the filter part and the connection point, and, 'wherein the high-pressure oil channel includes a check valve capable of preventing a backflow of the oil supplied to the low-pressure oil channel; and', 'a hydraulic-pressure adjustment valve disposed at a downstream side of the check valve and configured to adjust the hydraulic pressure of the oil., 'wherein the low-pressure oil channel includes2. The hydraulic device according to claim 1 , an introduction part for introducing the oil supplied from the supply pump;', 'a filter element having a mesh ...

Aircraft Landing Gear Steering Systems and Methods with Enhanced Shimmy Protection

An example aircraft includes (i) a landing gear having a chassis, an axle, and wheels mounted to ends of the axle; (ii) a hydraulic actuator including a cylinder, a first piston coupled to the chassis, and a second piston coupled to the axle; and (iii) a directional control valve including: inlet ports configured to be fluidly coupled to a source of pressurized fluid, tank ports configured to be fluidly coupled to a tank, and workports configured to be fluidly coupled to the hydraulic actuator. 1. A hydraulic system comprising:a hydraulic actuator comprising: (i) a cylinder, (ii) a partition disposed in the cylinder and configured to divide the cylinder into a first partition and a second partition, (iii) a first piston slidably accommodated in the first partition and having a piston head and a rod extending from the piston head along a longitudinal axis of the cylinder, wherein the rod is configured to be coupled to a chassis of a landing gear of an aircraft, and wherein the piston head divides the first partition into a first chamber and a second chamber, and (iv) a second piston slidably accommodated in the second partition and having a respective piston head and a respective rod extending from the respective piston head along the longitudinal axis of the cylinder, wherein the respective rod is configured to be coupled to an axle of the landing gear of the aircraft, and wherein the respective piston head divides the second partition into a third chamber and a fourth chamber; anda directional control valve comprising: (i) a first inlet port configured to be fluidly coupled to a source of pressurized fluid, (ii) a second inlet port configured to be fluidly coupled to the source of pressurized fluid, (iii) a first tank port configured to be fluidly coupled to a tank, (iv) a second tank port configured to be fluidly coupled to the tank, (v) a first workport configured to be fluidly coupled to the first chamber, (vi) a second workport configured to be fluidly coupled ...

Hydraulic pressure control device for swing motor for construction machinery

The present disclosure relates to a hydraulic pressure control device for a swing motor for construction machinery, and more particularly, to a hydraulic pressure control device for a swing motor for construction machinery, which supplements working fluid in the swing motor when a turning operation of an upper body of construction machinery is performed and then stopped. The hydraulic pressure control device for the swing motor for construction machinery according to the present disclosure including the aforementioned configuration may rapidly secure the amount of makeup fluid required by the swing motor when the swing motor is stopped by directly receiving the working fluid discharged from the hydraulic pump P, thereby improving durability of equipment and preventing a cavitation phenomenon.

Hydraulic Load-Sensing Control Arrangement

A hydraulic load-sensing control arrangement for a first and second hydraulic consumer has a variable displacement pump having load-sensing regulation, to which the highest respective load-sensing pressure of consumers is reported. The first consumer has the highest load pressure in normal operation and therefore the highest load-sensing pressure dependent on the load pressure. A pressure reducing valve is arranged in the pressure medium flow path between the variable displacement pump and the first consumer. A spring force from a regulating spring and a regulating pressure dependent on the load pressure of the first consumer are applied in the opening direction of a valve gate in this pressure reducing valve and pressure is applied directly downstream from the pressure reducing valve in the closing direction thereof. A pressure equivalent of the spring force of the regulating spring and the regulating pressure are greater than a pressure of the variable displacement pump. 1. A hydraulic load sensing control arrangement for a first and second hydraulic consumer , comprising:a hydraulic pump configured to supply the first and second consumers and including a load sensing regulating system to which a respectively highest load sensing pressure of the consumers, which is dependent on a load pressure, is indicated, the first consumer being configured to have the highest load pressure in normal operation of the control arrangement; anda pressure reducing valve located in a pressure medium flow path between the hydraulic pump and the first consumer, said pressure reducing valve having a valve spool configured to be subjected (i) in a closing direction to a pressure downstream of the pressure reducing valve and (ii) in an opening direction to a regulating pressure dependent on the load pressure of the first consumer and to a spring force of a regulating spring,wherein, in normal operation, a pressure equivalent of the spring force together with the regulating pressure is ...

HYDRAULIC DRIVE SYSTEM

A hydraulic cylinder causes a work implement to be lowered due to the exhaust of hydraulic fluid from a first chamber and the supply of hydraulic fluid to a second chamber. A hydraulic fluid flowpath has a first flowpath and a second flowpath. The first flowpath connects a first pump port and the first chamber. The second flowpath connects a second pump port and the second chamber. The hydraulic fluid flowpath configures a closed circuit between a hydraulic pump and the hydraulic cylinder. A bleed-off flowpath branches off from the first flowpath. A portion of hydraulic fluid exhausted from the first chamber when lowering the work implement flows into the bleed-off flowpath. 1. A hydraulic drive system , comprising:a hydraulic pump having a first pump port and a second pump port, the hydraulic pump being switchable between a state of inducting hydraulic fluid from the second pump port and discharging hydraulic fluid from the first pump port, and a state of inducting hydraulic fluid from the first pump port and discharging hydraulic fluid from the second pump port;a driving source configured to drive the hydraulic pump;a work implement;a hydraulic cylinder driven by hydraulic fluid discharged from the hydraulic pump, the hydraulic cylinder having a first chamber and a second chamber, the hydraulic cylinder being configured to lower the work implement by exhausting hydraulic fluid from the first chamber and supplying hydraulic fluid to the second chamber and raise the work implement by supplying hydraulic fluid to the first chamber and exhausting hydraulic fluid from the second chamber;a hydraulic fluid flowpath having a first flowpath connecting the first pump port and the first chamber and a second flowpath connecting the second pump port and the second chamber, the hydraulic fluid flowpath configuring a closed circuit between the hydraulic pump and the hydraulic cylinder;a bleed-off flowpath branching off from the first flowpath, the bleed-off flowpath having ...

FORKLIFT HYDRAULIC CONTROL APPARATUS

An outlet port of a hydraulic pump/motor and a bottom chamber of a lift cylinder are connected to each other by a hydraulic fluid passage. A hydraulic fluid passage that is connected to a hydraulic fluid tank is formed to branch off the hydraulic fluid passage. A flow control valve controls the hydraulic fluid delivered from the lift cylinder when the fork is lowered, thereby regulating the flow rate of hydraulic fluid supplied to the hydraulic pump/motor and the flow rate of hydraulic fluid supplied to the hydraulic fluid tank. If regenerative operation can be performed, the flow control valve is closed and hydraulic fluid is delivered to the hydraulic pump/motor. If regenerative operation cannot be performed, the flow control valve is opened and hydraulic fluid is delivered to the hydraulic fluid tank. In either case, the fork can be lowered at an instructed speed. 1. A hydraulic control apparatus for a forklift having a hydraulic lift cylinder that receives or discharges hydraulic fluid through manipulation of a raising/lowering manipulation member to selectively raise and lower a fork , the apparatus being characterized by:a hydraulic pump/motor;a first fluid passage for delivering hydraulic fluid delivered from the hydraulic lift cylinder to an outlet port of the hydraulic pump/motor when the fork is lowered;an outflow control mechanism provided in the first fluid passage to permit flow of hydraulic fluid from the hydraulic lift cylinder to the hydraulic pump/motor at the time when the fork is lowered but prohibit the flow of hydraulic fluid from the hydraulic lift cylinder to the hydraulic pump/motor at the time when the fork is stopped or raised;a second fluid passage branched from a section of the first fluid passage between the hydraulic pump/motor and the outflow control mechanism, wherein the second fluid passage delivers hydraulic fluid delivered from the hydraulic lift cylinder to a drain side; anda flow control valve provided in the second fluid ...

Mast with hydraulic circuit for assist cylinder

A mast assembly that includes a mast and a hydraulic circuit for moving the mast. The hydraulic circuit includes a primary hydraulic cylinder coupled to the mast to rotate the mast about a pivot axis and a secondary hydraulic cylinder extending from a rod end to a cap end that is fluidly coupled to the primary hydraulic cylinder. A directional valve is fluidly coupled between the primary hydraulic cylinder and secondary hydraulic cylinder to keep a pressure on the cap end of the secondary hydraulic cylinder greater than the pressure on the rod end of the secondary hydraulic cylinder during all operating conditions.

FLUID CONTROL ASSEMBLY AND SYSTEM

A fluid system includes a fluid control assembly in fluid communication with a fluid source in fluid communication with a fluid supply port and the fluid control assembly is in fluid communication with an actuator via an outlet port. A controller controls at least one supply valve and at least one exhaust valve. The at least one supply valve and exhaust valve are in a normally closed position until being actuated by the controller to an open position. The fluid control assembly includes a pressure sensor in communication with the outlet port. Whereby when pressure in the outlet port is less than a predetermined pressure, a controller opens the supply valve to communicate fluid to the actuator via the actuator line and when the pressure in the outlet port is greater than a predetermined pressure the controller opens the exhaust valve to vent the is outside a predetermined range. 1. A fluid control assembly , comprising:a first supply valve having a first supply valve inlet and a first supply valve outlet, the first supply valve being in a normally closed position in which fluid is unable to pass between the first supply valve inlet and the first supply valve outlet until the first supply valve is actuated to an open position in which fluid is able to pass between the first supply valve inlet and the first supply valve outlet;a first exhaust valve having a first exhaust valve inlet and a first exhaust valve outlet, the first exhaust valve being in a normally closed position in which fluid is unable to pass between the first exhaust valve inlet and the first exhaust valve outlet until the first exhaust valve is actuated to an open position in which fluid is able to pass between the first exhaust valve inlet and the first exhaust valve outlet; and a first supply port having a first supply passage in fluid communication with the first supply valve inlet;', 'a first outlet port having a first outlet passage in fluid communication with the first supply valve outlet, the ...

Hydraulic cable tensioning machine

Embodiments of the present invention disclose a hydraulic cable tensioning machine, comprising a tension puller for tensioning a cable, a hydraulic motor for controlling the action of the tension puller, and a hydraulic driving system for driving the hydraulic motor to operate, wherein an output end of the hydraulic driving system is connected to an input end of the hydraulic motor, and a power output end of the hydraulic motor is connected to a power input end of the tension puller.

Work Machine

To provide a work machine capable of efficiently regenerating the energy owned by hydraulic fluid during a swing deceleration. In the present invention, when a swing deceleration detection section 57 a detects the state of a revolving upperstructure 102 being decelerated, when an operation judgment section 57 c judges the state that a double-tilting pump/motor 14 is not supplying hydraulic fluid to any of a boom cylinder 1 and an arm cylinder 3 , and when the number of double-tilting pumps/motors 14, 18 having supplied hydraulic fluid to a swing hydraulic motor 7 in the state before the swing deceleration detection section 57 a detects the state of the revolving upperstructure 102 being decelerated is equal to one or more, a pump valve control section 57 d controls changeover valves 43 a, 45 b, 45 d, 49 d to open and increases the displacements of the double-tilting pumps/motors 14, 18 to the side to make suction pressures become higher than discharge pressures of the double-tilting pumps/motors 14, 18 so that the double-tilting pumps/motors 14, 18 operate as motors.

Control device and control method for solenoid valve

A control device for a solenoid valve that controls a solenoid valve included in a hydraulic control device using a control signal set through feedback control such that an actual current that flows through a solenoid of the solenoid valve matches a command current, including a command current setting device for setting the command current within a range of an upper-limit current. The command current setting device is operable for changing the upper-limit current from a first upper-limit value to a second upper-limit value that is smaller than the first upper-limit value in accordance with a reduction in voltage of a battery that supplies electric power to the solenoid.

DEVICE FOR CONTROLLING REGENERATED FLOW RATE FOR CONSTRUCTION MACHINE AND METHOD FOR CONTROLLING SAME

Disclosed are a device for controlling a regenerated flow rate for a construction machine and a method for controlling the same, the device being able to supply a large chamber of an arm cylinder with a part of operating oil, which is discharged from the arm cylinder to an operating oil tank during arm-in driving, and regenerating the same. The present invention provides a device for controlling a regenerated flow rate for a construction machine, the device being characterized by comprising: a variable capacity-type hydraulic pump and a pilot pump; an arm cylinder driven by operating oil supplied from the hydraulic pump; a variable arm regeneration valve installed in a passage between the arm cylinder and the operating oil tank; and an electronic proportional valve installed in a passage between the pilot pump and the arm regeneration valve. 1. A device for controlling a regeneration flow rate in a construction machine , comprising:a variable displacement hydraulic pump;a pilot pump;an arm cylinder actuated by working fluid supplied by the hydraulic pump;a variable arm regeneration valve disposed on a passage between the arm cylinder and a working fluid tank; andan electronic proportional valve disposed on a passage between the pilot pump and the arm regeneration valve.2. The device of claim 1 , further comprising:pressure sensors measuring levels of pressure in a larger chamber and a smaller chamber of the arm cylinder; anda controller calculating electrical signals corresponding to the levels of pressure measured by the pressure sensors and applying the calculated electrical signals to the electronic proportional valve.3. A device for controlling a regeneration flow rate in a construction machine claim 1 , comprising:a variable displacement hydraulic pump;a pilot pump;an arm cylinder actuated by working fluid supplied by the hydraulic pump;a variable arm regeneration valve disposed on a passage between the arm cylinder and a working fluid tank;an electronic ...

SYNCHRONIZING CYLINDER FOR EXTRUDER

A double-rod ram (), preferably for an extruder, comprising an outer cylinder (), an inner cylinder () installed therein and arranged concentrically therewith, a double-acting work piston () provided in the inner cylinder to be displaceable and a bypass device () with at least one bypass valve (), wherein the work piston () divides the inner cylinder () into two compartments () and can be loaded with a hydraulic fluid from both compartments (), wherein the bypass device () is so arranged that in a bypass position of the bypass valve () a fluid connection between the two compartments () is formed by a direct connection, preferably at least one bypass line, and in a work position of the bypass valve () no such fluid connection is present. 1. A double-rod ram for an extruder , the cylinder comprising:an outer cylinder extending along an axis;an inner cylinder installed therein and coaxial therewith;a double-acting work piston axially displaceable in the inner cylinder and subdividing same into a pair of compartments pressurizable with a hydraulic fluid;a bypass valve movable between a bypass position forming a direct fluid connection between the two compartments and a work position in which no such fluid connection is present.2. The double-rod ram according to claim 1 , wherein the direct connection is a bypass line formed between the outer cylinder and the inner cylinder of the double-rod ram.3. The double-rod ram according to claim 1 , wherein the bypass line is outside the double-rod ram housing.4. The double-rod ram according to claim 1 , wherein the bypass valve is biased by a return spring into the bypass position or the work position.5. The double-rod ram according to claim 4 , wherein the return spring is provided partly or completely inside the outer cylinder.6. The double-rod ram according to wherein the bypass valve is hydraulically actuatable.7. The double-rod ram according to claim 1 , wherein there are two of the bypass valves provided on opposite sides ...

HYDRAULIC TENSIONER WITH MOVING SLEEVE

Provided are tensioners to tension a closed loop chain of a chain drive system. The tensioners can include a housing with an open end, an enclosed end opposite the open end including an inlet supply, a bore extending from the open end to an area directly above the inlet supply to form a housing seat, a movable sleeve formed in the housing bore having an open end adjacent the open end of the housing, a closed end in contact with the housing seat, a sleeve bore extending from the open end to the closed end and a controlled inlet formed through the closed end thereof, a hollow piston disposed in the sleeve bore and a spring disposed in the piston bore to apply a bias on the piston outward from the sleeve bore. 1. A tensioner comprising:a housing having an open end, an enclosed end opposite the open end, an inlet fluid supply formed in the enclosed end, a housing bore extending from the open end through the housing to a seat formed directly above the inlet fluid supply, and a ratchet clip disposed in a groove formed circumferentially around the housing bore adjacent to the open end thereof;a movable sleeve slidingly disposed in the housing bore, the sleeve including an open end adjacent the open end of the housing, a closed end in contact with the seat, a bore extending from the open end through the sleeve to the closed end, and ratchet teeth formed along an outer circumference thereof such that the ratchet clip frictionally engages with consecutive ratchet teeth as the sleeve moves outward of the housing bore; anda piston slidingly disposed in the sleeve bore, the piston having a closed end adjacent the open end of the sleeve, an open end in fluid communication with the sleeve bore to form a high pressure chamber, and a piston spring extending from an inner side of the closed end to the check valve.2. The tensioner according to claim 1 , wherein fluid provided by the inlet fluid supply forces the moveable sleeve and piston to slide away from the housing seat.3. The ...

Actuator Limit Controller

In some applications, a piston of a hydraulic actuator may move at high speeds, and large undesired forces may be generated if the piston reaches an end-stop of the hydraulic actuator at a high speed. The undesired forces may, for example, cause mechanical damage in the hydraulic actuator. A controller may receive information indicative of the piston reaching a first position at a first threshold distance from the end-stop, and, in response, may modify a signal to a valve assembly controlling flow of hydraulic fluid to and from the hydraulic actuator. Further, the controller may receive information indicative of the piston reaching a second position at a second threshold distance closer to the end-stop of the hydraulic actuator, and, in response, the controller may further modify the signal to the valve assembly so as to apply a force on the piston in a away from the end-stop. 1. A method comprising:receiving, at a controller, a command for moving a piston of a hydraulic actuator at a given speed in a given direction, wherein the hydraulic actuator includes a first chamber and a second chamber, and wherein a valve assembly couples a source of pressurized hydraulic fluid to the first chamber and couples the second chamber to a return line;based on the command, the controller providing a signal to operate the valve assembly to provide the pressurized hydraulic fluid to the first chamber and allow hydraulic fluid in the second chamber to flow from the second chamber to the return line so as to cause motion of the piston at the given speed in the given direction;receiving position information indicative of the piston reaching a first position at a first threshold distance from an end-stop of the hydraulic actuator;in response, the controller modifying the signal to the valve assembly so as to reduce a speed of the piston;receiving position information indicative of the piston reaching a second position at a second threshold distance closer to the end-stop of the ...

Loop-flushing-system for hydrostatic apparatus

A hydraulic loop-flushing device ( 50 ) for a hydrostatic apparatus ( 1 ) comprising a valve housing ( 8 ) having a cylindrical valve bore ( 9 ) with a high pressure inlet ( 5 or 6 ), a low pressure inlet ( 6 or 5 ) and a discharge outlet ( 7 ). A first flushing valve spool ( 12 ) is arranged elastically pre-stressed within the valve bore ( 9 ) for enabling a fluid connection between the low pressure inlet ( 6 or 5 ) and the discharge outlet ( 7 ) by means of a first fluid channel ( 16 ). Further, a shuttle valve spool ( 22 ) is arranged elastically pre-stressed within the valve bore ( 9 ) for further enabling the fluid connection between the low pressure inlet ( 6 or 5 ) and the discharge outlet ( 7 ) by means of a fluid passageway ( 29 ). The first flushing valve spool ( 12 ) is moveable into an open position, in which the first fluid channel ( 16 ) is open, if the fluid pressure at the low pressure inlet ( 6 or 5 ) exceeds a first threshold value, and the shuttle valve spool ( 22 ) is moveable into an open position, in which the fluid passageway ( 29 ) is open for connecting the low pressure inlet ( 6 or 5 ) with the discharge outlet ( 7 ), if the pressure difference between the high pressure inlet ( 5 or 6 ) and the low pressure inlet ( 6 or 5 ) exceeds a second threshold value. For this the first flushing valve spool ( 12 ) and the shuttle valve spool ( 22 ) are arranged concentrically and moveable relative to each other, and the fluid connection between the low pressure inlet ( 6 or 5 ) and the discharge outlet ( 7 ) is enabled only, if both the first flushing valve spool ( 12 ) and the shuttle valve spool ( 22 ) are in the respective open positions.

Method for controlling flow rate of hydraulic pump of construction machine

A method is provided for controlling the flow rate of a hydraulic pump of a construction machine, including: a step of detecting the operation amount of a rotation operation lever, and the rotation pressure generated in a swing motor; a step of calculating the flow rate required for rotating, the flow rate corresponding to the operation amount of the rotation operation lever; a step of calculating a rotation acceleration first inclination value for increasing the discharge flow rate of the hydraulic pump to a certain inclination value from a rotation initiation time when the upper rotating body rotates; a step of calculating a second inclination value compensating for the first inclination value by a difference value between the detected rotation pressure value of the swing motor and the reference pressure corresponding to the set pressure of the relief valve of the swing motor; and to step of restricting the discharge flow rate of the hydraulic pump such that the increased amount of the flow rate required for rotating is restricted to the flow rate of the second inclination value.

Valve retaining cup

A valve including a valve housing, a casing, a spring guide, and a retaining cup. The casing may be disposed within the valve housing and may include a bore. The spring guide may be disposed within the bore and the retaining cup may be disposed partially around the casing to engage and retain the spring guide at least partially within the bore of the casing.

GENERATOR MOTOR FLOW CONTROL VALVE

A flow control manifold apparatus includes a housing defining a first flow path from a flow input port to flow output port and a second flow path from a return inlet port to a return outlet port. A first flow regulating valve is placed inline the first flow path and an excess flow path fluidly couples the first flow path to the second flow path. An excess pressure valve is placed inline the excess flow path and is in a closed orientation when the first flow regulating valve is open so that all of the fluid exits through the flow output port. The excess pressure valve is then in a partially open orientation when the first flow regulating valve is partially closed so that a first portion of the fluid exits through the flow output port and a second portion of the fluid exits through the return outlet port. 1. A flow control manifold apparatus comprising:a) a first flow path from a flow input port to flow output port and a second flow path from a return inlet port to a return outlet port;b) a first flow regulating valve inline said first flow path to regulate a flow rate of a fluid through said flow output port;c) an excess flow path fluidly coupling said first flow path to said second flow path; andd) an excess pressure valve inline said excess flow path wherein said excess pressure valve is configured to be in a closed orientation when said first flow regulating valve is open whereby all of the fluid exits through said flow output port, and wherein said excess pressure valve is configured to be in a partially open orientation when said first flow regulating valve is partially closed whereby a first portion of the fluid exits through said flow output port and a second portion of said fluid exits through said return outlet port.2. The flow control manifold apparatus of further comprising a pilot operated relief valve circuit including said excess pressure valve and a relief valve claim 1 , wherein when a fluid pressure of said fluid exceeds a predetermined threshold ...

LOAD-DEPENDENT HYDRAULIC FLUID FLOW CONTROL SYSTEM

The present disclosure relates to a load dependent flow control system for directing hydraulic fluid to a hydraulic actuator. The load dependent flow control system includes a closed-center valve device for controlling hydraulic fluid flow to the actuator. The closed-center valve device includes a valve spool and an electro-actuator that adjusts a position of the valve spool to adjust a rate of the hydraulic fluid flow supplied to the hydraulic actuator. A pressure sensor is provided for sensing a pressure of the hydraulic fluid provided to the hydraulic actuator. The system also includes an electronic controller configured to receive an operator flow command from an operator interface. The operator flow command corresponds to a base flow through the closed-center valve device. The electronic controller interfaces with the electro-actuator of the closed-center valve device and with the pressure sensor. At least when the sensed pressure is above a threshold pressure, the electronic controller uses the operator flow command and the sensed pressure to generate a pressure-modified flow command that is sent to the closed-center valve device to control flow through the closed-center valve device. The pressure-modified flow command corresponds to a pressure-modified flow through the closed-center valve device. The pressure-modified flow is less than the base flow through the closed-center valve device. 1. A load dependent flow control system for directing hydraulic fluid to a hydraulic actuator , the load dependent flow control system comprising:a closed-center valve device for controlling hydraulic fluid flow to the actuator, the closed-center valve device including a valve spool and an electro-actuator that adjusts a position of the valve spool to adjust a rate of the hydraulic fluid flow supplied to the hydraulic actuator;a pressure sensor for sensing a pressure of the hydraulic fluid provided to the hydraulic actuator; andan electronic controller configured to receive ...

PILOT TYPE SWITCHING VALVE

A pilot type switching valve includes: a housing bore formed in a valve body, the housing bore having an opening end; a spool slidably housed in the housing bore, the spool being configured to allow or block a flow of the working fluid to a first relief valve; a pilot chamber to which pilot pressure biasing the spool in the valve opening direction is guided; and a spring configured to bias the spool in the valve closing direction. The spool has a bottom surface on which the pilot pressure acts in such a manner that the spool is biased in the valve opening direction, and the area of the bottom surface is smaller than the sectional area of the housing bore. 1. A pilot type switching valve provided on the upstream side of a relief valve to be opened to discharge a working fluid to a tank when pressure of a supply flow passage connected to a pump reaches a predetermined value , the pilot type switching valve comprising:a valve body;a housing bore formed in the valve body, the housing bore having an opening end;a valve element slidably housed in the housing bore, the valve element being configured to allow or block a flow of the working fluid to the relief valve;a pilot chamber to which pilot pressure biasing the valve element in the valve opening direction is guided; anda bias member configured to bias the valve element in the valve closing direction, whereinthe valve element has a pressure receiving surface on which the pilot pressure acts in such a manner that the valve element is biased in the valve opening direction, andthe area of the pressure receiving surface is smaller than the sectional area of the housing bore.2. The pilot type switching valve according to claim 1 , whereinthe relief valve is provided in the valve body.3. The pilot type switching valve according to claim 1 , whereinthe valve element has an insertion borehole opened on an end surface,a piston is slidably inserted into the insertion borehole, andthe pilot chamber is formed between a bottom ...

PISTON ASSEMBLY FOR REPHASING A FLUID-DRIVEN ACTUATOR

In one aspect, a piston assembly for a fluid-driven actuator may include a piston defining a passage extending between first and second chambers of the actuator. The piston assembly may further include a valve having a valve head and a valve stem. The valve may be positioned within the passage and slidable between an open position and a closed position. The valve stem may extend outward from the passage into the second chamber when the valve is positioned in the closed position. Additionally, the piston assembly may include a spring compressed between the valve head and the piston. The spring may be configured to bias the valve to the closed position. The valve may be configured to move to the open position when a pressure in the second chamber exceeds a pressure threshold or when the valve stem contacts a cylinder of the fluid-driven actuator. 1. A piston assembly for a fluid-driven actuator , the piston assembly comprising:a piston separating first and second chambers of the fluid-driven actuator, the piston defining a passage extending between the first and second chambers;a valve including a valve head and a valve stem, the valve being positioned within the passage and slidable between an open position in which the valve head permits fluid flow through the passage and a closed position in which the valve head occludes fluid flow through the passage, the valve stem extending outward from the passage into the second chamber when the valve is positioned in the closed position; anda spring compressed between the valve head and the piston, the spring being configured to bias the valve to the closed position, wherein the valve is configured to move to the open position when a pressure in the second chamber exceeds a pressure threshold or when the valve stem contacts a cylinder of the fluid-driven actuator.2. The piston assembly of claim 1 , wherein the passage includes a first passage portion and a second passage portion claim 1 , the first passage portion having a ...

ASSEMBLY OF A SERVO PUMP AND A HYDRAULIC MOTOR

An assembly of a servo pump and a hydraulic motor. The assembly has a housing which contains the pump and the motor. The motor has a rotating body which rotates under the motive power of a pressurised motor liquid flow. The motor has a high pressure region which receives the pressurised motor liquid flow, and a low pressure region through which the motor liquid flow leaves the motor. The pump also has a rotating body. The pump has a low pressure region which receives servo liquid flow to be pumped by its rotating body, and a high pressure region through which pressurised servo liquid flow leaves the pump. Each rotating body is mounted on a respective journal. 1. An assembly of a servo pump and a hydraulic motor , wherein:the assembly has a housing which contains the servo pump and the hydraulic motor;{'sub': min', 'mout, 'the hydraulic motor has a rotating body which rotates under the motive power of a pressurised motor liquid flow, whereby the hydraulic motor has a high pressure region (P) which receives the pressurised motor liquid flow, and a low pressure region (P) through which the motor liquid flow leaves the hydraulic motor;'}{'sub': pin', 'pout, 'the servo pump has a rotating body, whereby the servo pump has a low pressure region (P) which receives servo liquid flow to be pumped by its rotating body, and a high pressure region (P) through which pressurised servo liquid flow leaves the servo pump;'}each rotating body is mounted on a respective journal, each journal being supported on one side of its rotating body by a respective first bearing block and being supported on the opposite side of its rotating body by a respective second bearing block, each bearing block having a running face adjacent to its rotating body and a non-running face distal from its rotating body;the assembly has a mechanical linkage having a coupling at one end to the journal of the motor rotating body and a coupling at an opposite end to the journal of the pump rotating body such that ...

ELECTROHYDRAULIC PROPORTIONAL PRESSURE CONTROL FOR OPEN CIRCUIT PUMP

A pump control assembly for controlling a variable displacement hydraulic pump includes a spool mounted within a valve block. The spool is configured to move between a first and a second position within the valve block so as to selectively control the displacement of the attached pump. The pump control assembly further includes first and second chambers that each apply a force to opposite ends of the spool. The first chamber is positioned at a first end of the spool in fluid communication with a pump output port. The second chamber is positioned at a second end of the spool and in fluid communication with a hydraulic tank port and a proportional pressure reducing valve. The second chamber also includes a piston and first and second springs positioned on either side of the piston. The proportional pressure reducing valve provides a regulated pressure to a first side of the piston along with the first spring, and the hydraulic tank port provides a tank pressure on the opposite side of the piston along with the second spring. The pump control assembly also includes a stop structure having a positive stop that limits movement of the piston in a direction toward the first chamber. 112.-. (canceled)13. A pump control assembly for controlling a variable displacement hydraulic pump , the pump control assembly comprising:a valve block defining a spool bore having a central bore axis, the valve block also defining a pump output port, a pump displacement control port, and a tank port;a spool mounted within the spool bore, the spool having a first end and an opposite second end, the spool being movable within the spool bore along the central bore axis between a first position where the tank port is in fluid communication with the pump displacement control port and a second position in which the pump output port is in fluid communication with the pump displacement control port, the spool moving in a first direction along the central bore axis when moving from the first position ...

HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE

The present disclosure relates to a hydraulic system for a construction machine, and more particularly, to a hydraulic system for a construction machine including a plurality of actuators, in which each of the actuators includes a pump/motor, is operated under a control of a corresponding pump/motor, and stores working oil in an accumulator or receives the working oil supplemented from the accumulator in accordance with a difference between a flow rate entering the actuator and a flow rate discharged from the actuator. 1. A hydraulic system for a construction machine , comprising:a pump/motor configured to serve as both a hydraulic pump driven by an engine and discharging working oil and a motor generating rotational force by the working oil;an actuator operated by receiving hydraulic pressure from the pump/motor and provided with first and second ports through which the hydraulic pressure flows in and out;first and second hydraulic pressure lines configured to connect the pump/motor and the actuator;an accumulator configured to store or discharge the working oil through the first and second hydraulic pressure lines and first and second bypass lines;first and second check valve units provided on the first and second bypass lines respectively and configured to allow the working oil to move only to the first and second hydraulic pressure lines; anda control valve unit, of which both pressure receiving portions are connected with the first and second hydraulic pressure lines, and switched so that a hydraulic pressure line having lower pressure between the first and second hydraulic pressure lines communicates with the accumulator.2. (canceled)3. The hydraulic system of claim 1 , wherein the control valve unit comprises an internal flow path comprising a second position connecting the first hydraulic pressure line and the accumulator claim 1 , a third position connecting the second hydraulic pressure line and the accumulator claim 1 , and a first position blocking ...

SLEWING DRIVE APPARATUS FOR CONSTRUCTION MACHINE

Provided is a slewing drive apparatus for a construction machine capable of satisfactory pump-flow-rate control regardless of change in engine speed, including a variable displacement hydraulic pump, a slewing motor, a slewing operation device, a control valve, a relief valve, and a pump-flow-rate control device that performs a relief cut control and includes: a section for detecting an engine revolution number Ne and a slewing speed of a slewing body; a section for determining a target pump flow rate Qo that is a sum of a slewing-speed correspondence flow rate Q and a minimum required relief flow rate Qmin; a section for determining a target pump-tilt-angle qtg obtained by dividing the target pump flow rate Qo by the detected engine revolution number Ne; and a section for adjusting an actual pump-tilt-angle of the hydraulic pump so as to bring the actual pump-tilt-angle to the target pump-tilt-angle qtg. 1. A slewing drive apparatus to be installed on a construction machine including a slewing body to slew the slewing body , the slewing drive apparatus comprising:an engine;a variable displacement hydraulic pump that is driven by the engine to thereby discharge a hydraulic fluid;a slewing motor that slews the slewing body;a slewing operation device that receives an operation for actuating the slewing motor and outputs a slewing command corresponding to the operation;a control valve that makes a valve opening action so as to control the actuation of the slewing motor, in response to the slewing command output by the slewing operation device;a relief valve that defines a maximum pressure of the slewing motor; anda pump-flow-rate control device that controls a pump-tilt-angle determining a pump flow rate that is a discharge flow rate of the hydraulic pump, characterized in that{'b': '1', 'the pump-flow-rate control device performing a relief cut control and including: a section for detecting an engine revolution number Ne and a slewing speed of a slewing body; a ...

Fluid pressure control device

A fluid pressure control device includes a switching valve that has a pilot chamber to which the working oil is supplied from the supply passage through the second control valve, and a first relief valve that is provided on the downstream side of the switching valve. The second control valve allows supply of the working oil to the pilot chamber in a case where a flow of the working oil to a tilt cylinder is allowed, and blocks the supply of the working oil to the pilot chamber in a case where the flow of the working oil to the tilt cylinder is blocked. The switching valve allows a flow of the working oil to the first relief valve in a case where the working oil is supplied to the pilot chamber, and blocks the flow of the working oil to the first relief valve in a case where the supply of the working oil to the pilot chamber is blocked.

Switching unit and pneumatic system

A switching unit may be provided for connecting a first pneumatic unit and a second pneumatic unit of a pneumatic system together. The switching unit comprises a main body having: a channel structure which extends through the main body; a first and a second inlet for introducing a pressure into the channel structure; a first and a second outlet for discharging at least some of the pressure from the channel structure; and a first and a second valve; wherein the first inlet can be brought into a pressure-exchange connection to the first outlet via a first channel by setting a first switch position of the first valve or to the second outlet via a second channel by setting a second switch position of the first valve, and wherein the second inlet can be brought into a pressure-exchange connection to the first outlet via a third channel by setting a first switch position of the second valve or to the second outlet via a fourth channel by setting a second switch position of the second valve.

HYDRAULIC BYPASS CIRCUIT

Disclosed embodiments include hydraulic systems which provide power to lift, tilt and auxiliary (e.g., implement) functions, including high-flow auxiliary functions, with increased efficiency. Disclosed embodiments incorporate a single variable displacement pump that supplies pressurized fluid to a main control valve (e.g., for lift, tilt, and auxiliary functions) and a bypass circuit. The main control valve supplies fluid to control lift, tilt, and auxiliary flow for implements. The bypass circuit combines flow with the output of the auxiliary section of the main control valve to optionally provide high-flow for selected implements. The single variable displacement pump can then be set to different output flow levels, with the bypass circuit functioning differently under different conditions to optimize hydraulic flow to carryout various tasks under various conditions. 1. A circuit of a power machine for providing power to at least one implement actuator of an implement mounted on the power machine , the hydraulic circuit comprising:an implement pump configured to receive hydraulic fluid from a tank through an input conduit and to supply a flow of pressurized hydraulic fluid at an implement pump outlet conduit;a main control valve coupled to the implement pump output conduit and configured to provide pressurized hydraulic fluid from the implement pump to the at least one implement actuator through a control valve output conduit; anda bypass circuit having an inlet conduit coupled to the implement pump outlet conduit to selectively receive a portion of the flow of pressurized hydraulic fluid from the implement pump and to provide the portion of the flow of pressurized hydraulic fluid to the at least one implement actuator at a bypass circuit output conduit coupled to the control valve output conduit such that flow of pressurize hydraulic fluid provided to the at least one implement actuator is a combined flow including flow through the main control valve and flow ...

CONTROL SYSTEM, WORK MACHINE, AND CONTROL METHOD

A control system includes: an engine; a first hydraulic pump and a second hydraulic pump driven by the engine; a switching device provided in a flow path that connects the first hydraulic pump to the second hydraulic pump, and configured to perform switching between a merged state in which the flow path is opened and a separated state in which the flow path is closed; a first hydraulic actuator to which hydraulic fluid discharged from the first hydraulic pump is supplied in the separated state; a second hydraulic actuator to which hydraulic fluid discharged from the second hydraulic pump is supplied in the separated state; a determining unit configured to determine whether output of the engine is limited; and a merging-separating control unit configured to control the switching device so as to perform switching to the merged state when the determining unit determines that output of the engine is limited. 1. A control system comprising:an engine;a first hydraulic pump and a second hydraulic pump driven by the engine;a switching device provided in a flow path that connects the first hydraulic pump to the second hydraulic pump, and configured to perform switching between a merged state in which the flow path is opened and a separated state in which the flow path is closed;a first hydraulic actuator to which hydraulic fluid discharged from the first hydraulic pump is supplied in the separated state;a second hydraulic actuator to which hydraulic fluid discharged from the second hydraulic pump is supplied in the separated state;a determining unit configured to determine whether output of the engine is limited; anda merging-separating control unit configured to control the switching device so as to perform switching to the merged state when the determining unit determines that output of the engine is limited.2. The control system according to claim 1 , further comprising an exhaust gas treatment device configured to treat an exhaust gas of the engine claim 1 ,wherein the ...

Hydraulic apparatus, in particular hydraulic valve or hydraulic regulator

The present invention relates to a hydraulic apparatus, in particular to a hydraulic valve or to a hydraulic regulator, having a housing, at least one piston axially displaceably supported in a housing bore, and a respective at least one compression spring acting on the at least one piston, wherein at least one externally accessible regulating screw is adjustable within the housing bore to set the preload of the compression spring in the axial direction, wherein the adjustment distance of the at least one regulating screw is divided into at least two adjustment ranges and the torque to be applied for the adjustment of the regulating screw is larger in a second adjustment range than in a first adjustment range.

ENERGY RECOVERY SYSTEM HAVING PEAK-SHAVING ACCUMULATOR

An energy recovery system for a machine is disclosed. The energy recovery system may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, an actuator, and an actuator control valve movable to direct pressurized fluid from the pump to the actuator and from the actuator to the tank to move the actuator. The energy recovery system may also have a motor connected to selectively receive fluid discharged from the actuator and mechanically connected to the pump, and an accumulator configured to store fluid discharged from the motor and to direct stored fluid to the motor to drive the pump. 1. An energy recovery system , comprising:a tank;a pump configured to draw fluid from the tank and pressurize the fluid;an actuator;an actuator control valve movable to direct pressurized fluid from the pump to the actuator and from the actuator to the tank to move the actuator;a motor connected to selectively receive fluid discharged from the actuator and mechanically connected to the pump; andan accumulator configured to store fluid discharged from the motor and to direct stored fluid to the motor to drive the pump.2. The energy recovery system of claim 1 , further including a motor control valve disposed downstream of the motor and movable to selectively direct fluid discharged from the motor into the tank or into the accumulator.3. The energy recovery system of claim 2 , further including a charge valve fluidly connected between the actuator and the motor.4. The energy recovery system of claim 3 , further including a check valve located upstream of the charge valve.5. The energy recovery system of claim 3 , further including an accumulator control valve disposed between the accumulator and an inlet of the motor.6. The energy recovery system of claim 5 , wherein:the charge valve and accumulator control valve are variable position valves; andthe motor control valve is a 2-position valve.7. The energy recovery system of claim 5 , further including a ...

ELECTROHYDRAULIC CONTROL DEVICE FOR CONSTRUCTION MACHINE AND METHOD THEREOF

An electro-hydraulic control apparatus for construction machinery includes a control valve installed in a hydraulic line between a hydraulic pump and an actuator to control operations of the actuator according to a displacement amount of a spool therein, a spool displacement adjusting valve configured to output a secondary pressure in proportion to an inputted pressure command signal to the spool of the control valve to control the displacement amount of the spool of the control valve, a pressure sensor to detect the secondary pressure outputted from the spool displacement adjusting valve, and a controller configured to output the pressure command signal to the spool displacement adjusting valve according to a manipulation signal of the construction machinery, and to correct the pressure command signal when a pressure difference between the detected secondary pressure and a design pressure predetermined by the pressure command signal is out of a preset allowable range. 1. An electro-hydraulic control apparatus for construction machinery , comprising:a control valve installed in a hydraulic line between a hydraulic pump and an actuator to control operations of the actuator according to a displacement amount of a spool therein;a spool displacement adjusting valve configured to output a secondary pressure in proportion to an inputted pressure command signal to the spool of the control valve to control the displacement amount of the spool of the control valve;a pressure sensor to detect the secondary pressure outputted from the spool displacement adjusting valve; anda controller configured to output the pressure command signal to the spool displacement adjusting valve according to a manipulation signal of the construction machinery, and to correct the pressure command signal when a pressure difference between the detected secondary pressure and a design pressure predetermined by the pressure command signal is out of a preset allowable range.2. The electro-hydraulic ...

Substance Dispensing System

A substance dispensing system that includes a hydraulic drive system is disclosed. The hydraulic drive system includes a hydraulic valve having a variable pressure setting, the hydraulic valve operable between a closed position in which a hydraulic pump moves hydraulic fluid to a hydraulic cylinder and an open position in which the hydraulic pump moves the hydraulic fluid to a hydraulic reservoir. The substance dispensing system of the present disclosure provides a system that recirculates hydraulic fluid in a hydraulic drive system instead of recirculating a substance back to a container via a pump. The substance dispensing system of the present disclosure allows for precise, accurate, and instantaneous control of an external force in a substance dispensing system. 1. A substance dispensing system , comprising a drive system including a valve having a variable pressure setting , the valve operable between a closed position in which the drive system moves a fluid to an actuation member via a supply line thereby actuating the actuation member and an open position in which the drive system recirculates the fluid to a reservoir via a relief line thereby relieving the fluid moved to the actuation member and stopping movement of the actuation member.2. The substance dispensing system of claim 1 , further comprising a substance containment system in communication with the actuation member of the drive system claim 1 , the substance containment system comprising a container having a deformable wall and defining a container interior adapted to hold a substance claim 1 , the substance contained within the container at a substance pressure claim 1 , wherein the actuation member is movably positionable relative to the container.3. The substance dispensing system of claim 2 , wherein the substance containment system further comprises an interruption means for stopping flow of the substance from the container to provide a resistance that resists movement of the actuation member ...

Oil Return Mechanism

An oil return mechanism includes a base, a control switch, a first blocking ball mounted in the base, an elastic member mounted between the first blocking ball and the base. The base has a liquid storing cavity, a liquid returning cavity, a communicating cavity, a first communicating opening communicating between the liquid returning cavity and the communicating cavity, and a second commit eating opening communicating between the communicating cavity and the liquid storing cavity. The present invention can regulate a speed of a fluid flowing from the liquid returning cavity to the communicating cavity, and has the advantages of simple structure and great reduction of cost.

HYDRAULIC DRIVE

In a hydraulic drive of a tool, a piston is adapted to be acted upon by a pump via a pressure limiting seat valve and a parallel switching seat valve of a valve arrangement. A restriction is provided in a pressure line upstream of the pressure limiting seat valve which is connected to a tank on the flow-off side. A drain line leads from a working chamber of the piston via the switching seat valve to the tank. A closing side is adapted to be acted upon by pressure and an opening side is adapted to be acted upon by a force generated when the pressure limiting seat valve responds. The pump is adapted to be switched off when the maximum operating pressure has been reached, so that the piston will execute a return stroke. A pressure-increasing restriction is provided on the flow-off side of the pressure limiting seat valve. 1. A hydraulic drive for a tool , the hydraulic drive comprising:a pump;a valve arrangement including a pressure limiting seat valve and a parallel switching seat valve;a working chamber;a piston in the working chamber, the piston being adapted to be acted upon on one side thereof against a permanent load by the pump, which is operable in a switch-off mode, via the valve arrangement;a pressure line from the pump to the working chamber;a restriction provided in the pressure line upstream of the pressure limiting seat valve;a tank connected to the pressure limiting seat valve on a flow-off side;a drain line connected to the pressure line downstream of the restriction, the drain line leading from the working chamber via the switching seat valve to the tank;wherein a closing side of the switching seat valve is adapted to have applied thereto pressure from the pressure line upstream of the restriction, an opening side of the switching seat valve is adapted to have applied thereto a force generated when the pressure limiting seat valve responds, the pressure limiting seat valve has on a spring-loaded valve piston a first pressure application surface, which ...

PNEUMATIC BOOSTER AND BRAKE SYSTEM

A pneumatic booster () disposed between a brake pedal () and a master cylinder () includes a cylindrical member () provided on an outer circumferential side of an output rod (). A seal member () seals between an outer circumferential side of the cylindrical member and a cylindrical portion of a front shell, and an O-ring seals between the cylindrical member and the output rod. The cylindrical member causes a differential pressure between a negative pressure chamber (A) and an atmosphere chamber (C) to be applied to a valve body (). One axial side of the cylindrical member is configured to cause an atmosphere pressure to be applied to the valve body by abutting against a cylindrical protruding portion of the valve body, thereby pushing the valve body with the aid of the differential pressure in the direction as a biasing direction of a return spring.

SWITCHING VALVE, SWITCHING HYDRAULIC SYSTEM AND CRANE

The present application relates to a switching valve, a switching hydraulic system, and a crane, in which the switching valve having an oil inlet and an oil outlet comprises at least two pairs of valve oil ports, a pair of cartridge valves provided between each pair of valve oil ports, and the oil inlet and the oil outlet are controlled such that the oil inlet and the oil outlet are capable of shifting between communications with the at least two pairs of valve oil ports. The switching valve switches on and off communication between the oil inlet and the oil outlet and the at least two pairs of valve oil ports by controlling opening or closing of the cartridge valves. 1. A switching valve having an oil inlet and an oil outlet , comprising at least two pairs of valve oil ports , said at least two pairs of valve oil ports comprises a first pair of valve oil ports and a second pair of valve oil ports , said first pair of valve oil ports comprises a first valve oil inlet port and a first valve oil return port , a first cartridge valve is provided between said first valve oil inlet port and said oil inlet , a second cartridge valve is provided between said first valve oil return port and said oil outlet , said second pair of valve oil ports comprises a second valve oil inlet port and a second valve oil return port , a third cartridge valve is provided between said second valve oil inlet port and said oil inlet , a fourth cartridge valve is provided between said second valve oil return port and said oil outlet , said switching valve further comprises:a supplying oil passage for supplying oil to a control port of said first cartridge valve, a control port of said second cartridge valve, a control port of said third cartridge valve and a control port of said fourth cartridge valve;a pressure relief oil passage for relieving pressures on a control port of said first cartridge valve, a control port of said second cartridge valve, a control port of said third cartridge valve ...

Fluid Pump for a Linear Actuator

A fluid pump for a linear actuator is provided. The pump causes a rod in the actuator to extend or retract by controlling the flow of fluid to and from portions of a fluid chamber on either side of a piston disposed within the fluid chamber and supporting the rod. The pump includes a valve structure that enables the pump to redistribute fluid obtained from one portion of the fluid chamber on one side of the piston to the other portion of the fluid chamber on the other side of the piston without first returning the fluid to a fluid reservoir thereby increasing the efficiency of the pump. 1. A fluid pump for a linear actuator , comprising:a housing defining an inlet port configured for fluid communication with a fluid reservoir and first and second outlet ports configured for fluid communication with first and second portions of a fluid chamber formed on opposite sides of a piston disposed within said fluid chamber;a driven pump element disposed within said housing;a first shuttle movable between a first fluid flow position permitting fluid flow between said inlet port and said driven pump element along a first fluid flow path and a second fluid flow position permitting fluid flow between said inlet port and said driven pump element along a second fluid flow path;a first check valve movable between a closed position and an open position permitting fluid flow between said driven pump element and said first outlet port;a second check valve movable between a closed position and an open position permitting fluid flow between said driven pump element and said second outlet port; and, a second shuttle movable between a first position in which said second shuttle causes said first check valve to assume said open position and a second position in which said second shuttle causes said second check valve to assume said open position;wherein rotation of said driven pump element in a first rotational direction results in movement of said first shuttle to said first fluid flow ...

SOD HARVESTER HYDRAULIC SYSTEM FOR ACTUATING COMPONENTS WITH PRECISE TIMING

Sod harvesters can have hydraulic systems that are configured to actuate components with precise timing. The hydraulic system of a sod harvester can be configured to maintain the temperature of hydraulic fluid both during harvesting and while harvesting is paused to thereby eliminate or minimize the occurrence of periods of variation in the timing of actuation of the components that the hydraulic fluid drives. As a result, these components can be consistently actuated with precise timing even after harvesting has been paused. Additionally, such configurations can minimize the amount of time required to warm the hydraulic fluid to a steady operational temperature. 1. A sod harvester comprising:a cutting head for cutting sod from the ground;a stacking conveyor configured to receive the sod;a stacking head configured to remove the sod from the stacking conveyor for stacking; and a pump;', 'an actuator for each hydraulically actuated component, each actuator being configured to actuate the corresponding hydraulically actuated component;', 'a first hydraulic line coupled to one end of each actuator;', 'a second hydraulic line connected to an opposite end of each actuator;', 'a control valve for coupling either the first or the second hydraulic line to the pump; and', 'a bypass valve coupled between the first and second hydraulic lines to thereby allow hydraulic fluid to flow between the first and second hydraulic lines., 'a hydraulic system for controlling at least one hydraulically actuated component of the sod harvester, the hydraulic system including2. The sod harvester of claim 1 , wherein the bypass valve includes a throttle valve and a check valve.3. The sod harvester of claim 1 , wherein the bypass valve is external to the actuator for each hydraulically actuated component.4. The sod harvester of claim 1 , wherein the bypass valve is internal to the actuator for each hydraulically actuated component.5. The sod harvester of claim 4 , wherein the at least one ...

Pressure-regulating valve

A pressure-regulating valve having a valve piston (I 0 ) which is subjected to the action of an energy store and which is guided in longitudinally displaceable fashion in a valve housing ( 12 ), which valve housing has ports such as a supply port ( 14 ), a utility port ( 16 ) and a tank port ( 18 ), which ports can be actuated, by way of a control part ( 20 ) which closes with a sealing action, such that, in the case of a fluidic connection from the supply port to the utility port, a pressure reduction function is realized, and in the case of a fluidic connection from the utility port to the tank port, a pressure-limiting function is realized, characterized in that the control part ( 20 ) has a control rod ( 22 ) with two control bodies ( 24, 26 ) held spaced apart from one another, of which control bodies one ( 24 ) controls at least the fluidic connection between supply port ( 14 ) and utility port ( 16 ), and the other control body ( 26 ) controls at least the fluidic connection between utility port ( 16 ) and tank port ( 18 ).

ELECTRIC HYDRAULIC ACTUATOR

Disclosed is an electric hydraulic actuator including a hydraulic cylinder and the hydraulic power generator. The hydraulic cylinder includes a hollow rod that is connected to a piston and is linearly movable to protrude outward or to retract. The hydraulic power generator includes a motor, a fluid tank, and a gear pump and a pilot check valve disposed in a pump housing. The cylinder housing and the pump housing are directly coupled to each other. The cylinder housing includes a first port through which the working fluid is transferred to a first side of the piston and a second port connected to a return pipe that is provided in the hollow rod. The pump housing includes a third port that is configured to communicate with the first port and a fourth port that is configured to communicate with the second port. 1. An electric hydraulic actuator comprising:a hydraulic cylinder including a hollow rod that is connected to a piston and is linearly movable to protrude outward or to retract when a working fluid is supplied to or discharged from a cylinder housing; anda hydraulic power generator including a motor, a fluid tank, and a gear pump and a pilot check valve disposed in a pump housing, the hydraulic power generator converting a rotational force of the motor into a hydraulic pressure and transferring the hydraulic pressure to the hydraulic cylinder,wherein the cylinder housing and the pump housing are directly coupled to each other,the cylinder housing includes a first port through which the working fluid is transferred to a first side of the piston so that the hollow rod is driven outward to protrude an increased distance from a leading end of the cylinder tube and a second port connected to a return pipe that is provided in the hollow rod and through which the working fluid is discharged from the hollow rod, andthe pump housing includes a third port that is configured to communicate with the first port and through which the working fluid extracted from the fluid ...

CABIN CONTROL VALVE INTEGRATED WITH SOLENOID VALVE

A cabin control valve integrated with solenoid valve comprises solenoid valve which is connected at least one of the ports provided on to cabin control valve. The present invention provides a simple pneumatic or hydraulic circuit for operation of the cabin control valve; efficiently cabin control valve with solenoid valve which is easy to operate. 1100. A cabin control valve integrated with solenoid direction control valve characterised by:{'b': 10', '20, 'a. solenoid direction control valve configured within cabin control valve at port P;'}{'b': 10', '04', '20', '50', '10, 'b. pressurised air enters into solenoid direction control valve from inlet port of the cabin control valve to inlet of solenoid direction control valve at port P;'}{'b': '10', 'c. solenoid direction control valve is configured with monitoring sensors;'}{'b': '10', 'd. solenoid direction control valve allows pressurised air to enter into cylinder for operation after receiving signal from monitoring sensors;'}{'b': 10', '60, 'e. after completion of operation previous pressurised air is discharged from solenoid direction control valve by means of exhaust port ;'}{'b': 10', '50', '20', '60', '10', '10', '50, 'wherein, deenergised condition of solenoid direction control valve prevents pressurised air to enter into cylinder through inlet and previous pressurised air from the cabin control valve escape from exhaust port of the solenoid direction control valve ; energised condition of solenoid direction control valve allows pressurised air to enter into cylinder through inlet for operation.'}2. The cabin control valve integrated with solenoid direction control valve as claimed in claim 1 , wherein sensor detects the position of vehicle parked on flat surface then said sensors triggers to cabin control valve for such operations.3. The cabin control valve integrated with solenoid direction control valve as claimed in claim 1 , wherein solenoid direction control valve which is connected at least one of the ...

FLUID PRESSURE CIRCUIT

A fluid pressure circuit for controlling a rod of a cylinder controlled in accordance with an operation command includes a tank, a fluid pressure actuator configured to pressurize fluid supplied from the tank for extending and retracting the cylinder, a flow control valve arranged between the fluid pressure actuator and the cylinder device configured to switch a flow passage of pressurized fluid and discharge via a first throttle return fluid from the cylinder, a variable regeneration switching valve configured to discharge return fluid from the cylinder to the flow control valve upon non-regeneration and upon regeneration, branch part of the return fluid and discharge via a second throttle the fluid branched, a regenerative motor configured for regeneration by fluid branched by the variable regeneration switching valve, and a third throttle connected in series with the first throttle upon the regeneration to limit flow of return fluid. 1. A fluid pressure circuit for controlling a rod stroke of a cylinder device in accordance with an operation command , the fluid pressure circuit comprising:a tank having a fluid stored therein;a fluid pressure actuator configured to pressurize the fluid supplied from the tank for extending and retracting the cylinder device;a flow control valve arranged between the fluid pressure actuator and the cylinder device and configured to switch a flow passage of the pressurized fluid and to discharge via a first throttle the fluid returned from the cylinder device;a variable regeneration switching valve configured to discharge the fluid returned from the cylinder device to the flow control valve upon non-regeneration of fluid energy and to, upon regeneration of the fluid energy, branch part of the fluid returned from the cylinder device and discharge via a second throttle the fluid branched;a regenerative motor configured to be driven for the regeneration by the fluid brandied by the variable regeneration switching valve; anda third ...

LIFTING ARRANGEMENT

A back-up load retention system includes a retention line which is connected to a load, a counterweight unit which is connected to the retention line, and a double-acting hydraulic cylinder which is connected to the counterweight unit. The counterweight unit maintains a tension force in the retention line. The double-acting hydraulic cylinder brakes and/or stops the load in a case of a failure in a main lifting system. 112-. (canceled)13. A back-up load retention system comprising:a retention line configured to be connected to a load;a counterweight unit connected to the retention line, the counterweight unit being configured to maintain a tension force in the retention line; anda double-acting hydraulic cylinder connected to the counterweight unit, the double-acting hydraulic cylinder being configured to at least one of brake and stop the load in a case of a failure in a main lifting system.14. The back-up load retention system as recited in claim 13 , further comprising:a plurality of sheaves,wherein,the retention line is connected to the counterweight unit via the plurality of sheaves.15. The back-up load retention system as recited in claim 14 , wherein the plurality of sheaves are arranged to provide a gearing ratio between a weight of the counterweight unit and the tension force in the retention line.16. The back-up load retention system as recited in claim 13 , further comprising:at least one guide rail which is configured to support a motion of the counterweight unit.17. The back-up load retention system as recited in claim 13 , wherein claim 13 ,the double-acting hydraulic cylinder comprises a rod side and a piston side, andfurther comprising:at least one hydraulic circuit arranged between the rod side and the piston side of the double-acting hydraulic cylinder, the at least one hydraulic circuit being configured to form at least one connection between the rod side and the piston side.18. The back-up load retention system as recited in claim 17 , wherein ...

HYDRAULIC HYBRID SYSTEMS, COMPONENTS, AND CONFIGURATIONS

An example embodiment includes a hydraulic hybrid system. The hydraulic hybrid system includes a hydraulic system, an energy source configured to produce primary kinetic energy, an output configured to receive at least a first portion of the primary kinetic energy, and a transmission coupled between the energy source and the output and selectively coupled to the hydraulic system. The hydraulic system includes a reservoir, a sequenced accumulator assembly, and a hydraulic pump/motor that is hydraulically coupled to the reservoir and the sequenced accumulator assembly and configured to charge the sequenced accumulator assembly when mechanically driven. The sequenced accumulator assembly includes two or more accumulators, one or more sequence valves, and one or more check valves. The sequenced accumulator assembly is configured to store varying amounts of potential hydraulic energy by introducing and removing one or more of the accumulators from operation. 1. A hydraulic hybrid system comprising:a hydraulic system;an energy source configured to produce primary kinetic energy;an output configured to receive at least a first portion of the primary kinetic energy; and a reservoir;', 'a sequenced accumulator assembly that includes a first accumulator, a second accumulator, and a third accumulator;', 'a hydraulic pump/motor that is hydraulically coupled to the reservoir and the sequenced accumulator assembly and configured to charge the sequenced accumulator assembly when mechanically driven;', 'a reverse free flow check valve;', 'a dump valve; and', 'a sequence valve, wherein the sequence valve is configured to sequentially fill the second accumulator and the third accumulator as pressure in the first accumulator increases and configured to sequence the filling of the second accumulator and the third accumulator smoothly., 'a transmission coupled between the energy source and the output and selectively coupled to the hydraulic system, wherein the hydraulic system includes2 ...

Hydraulic equipment for excavators and operating machines in general

Hydraulic equipment of the type that can be fixed to a moving arm of an operating machine. The equipment has a support structure connected or connectable to a moving arm of an operating machine, at least one hydraulic motor for the rotation of a working element, a feed pipe connected or connectable to a hydraulic circuit of the supporting operating machine to supply a flow of working fluid to the hydraulic motor, and a drainage unit for the drainage of working fluid from the hydraulic motor. The equipment may optionally include a pressure detector in the drainage unit and a shut-off valve operationally associated with the pressure detector in such a way as to interrupt the flow of working fluid to the hydraulic motor when predetermined pressure conditions are detected.

CONTROL SYSTEM FOR CONSTRUCTION MACHINERY

A control system for construction machinery includes a main control valve installed in a hydraulic line between a hydraulic pump and actuators, and including a first group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a first spool for controlling a first group of actuators of the actuators, and a second group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a second spool for controlling a second group of actuators of the actuators, a first pressure sensor configured to detect the secondary pressure outputted from the first group of electro proportional pressure reducing valves and a second pressure sensor configured to detect the secondary pressure outputted from the second group of electro proportional pressure reducing valves, and a controller configured to output pressure command signals to the electro proportional pressure reducing valves corresponding to a manipulation signal of the construction machinery, and configured to compare the secondary pressures detected by the first and second pressure sensors and the pressure command signals to determine to determine whether or not the electro proportional pressure reducing valves fail. 1. A control system for construction machinery , comprising:a main control valve installed in a hydraulic line between a hydraulic pump and actuators, and including a first group of electro proportional pressure reducing valves outputting a first secondary pressure in proportion to a first pressure command signal to a first spool for controlling a first group of actuators of the actuators, and a second group of electro proportional pressure reducing valves outputting a second secondary pressure in proportion to a second pressure command signal to a second spool for controlling a second group of actuators of the actuators;a first pressure sensor configured ...

HYDRAULIC SYSTEM AND A METHOD FOR CONTROLLING A HYDRAULIC SYSTEM

A hydraulic system for a working machine includes a hydraulic actuator and a first hydraulic machine for supplying fluid to the hydraulic actuator. The hydraulic system further includes a hydraulic transformer for supplying fluid to the hydraulic actuator in parallel with the first hydraulic machine, and an accumulator for fluid. The hydraulic transformer includes a first port and a second port and the transformer is adapted to transform a first pressure and a first flow at the first port to a second pressure and a second flow at the second port. The second port of the hydraulic transformer is in fluid communication with the hydraulic actuator and the first port is in communication with the accumulator. 116-. (canceled)17. A hydraulic system for a working machine , the hydraulic system comprisinga hydraulic actuator and a first hydraulic machine for supplying fluid to the hydraulic actuator, anda hydraulic transformer for supplying fluid to the hydraulic actuator in parallel with the first hydraulic machine, and an accumulator for fluid, the hydraulic transformer comprising a first port and a second port and being adapted to transform a first pressure and a first flow at the first port to a second pressure and a second flow at the second port, the second port of the hydraulic transformer being in fluid, communication with the hydraulic actuator and the first port being in communication with the accumulator, anda hydraulic actuator controller being adapted to determine a required hydraulic power for the hydraulic actuator, wherein the hydraulic actuator controller further is adapted to request a first power portion of the required hydraulic power from the hydraulic transformer and a second power portion of the required hydraulic power from the first hydraulic machine.18. The hydraulic system according to claim 17 , wherein the hydraulic system comprises a first conduit assembly and the first hydraulic machine is adapted to supply fluid to the hydraulic actuator via ...

HYDRAULIC CONTROL CIRCUIT FOR A CONSTRUCTION MACHINE

To make it possible to control supply, discharge, and recycled flow rates independently of each other for the stick cylinder in a construction machine comprising first and second stick spool valves respectively connected to first and second hydraulic pumps. [Solution] A poppet valve is provided at upstream side of the first stick spool valve for controlling a supply flow rate from first hydraulic pump, the first stick spool valve is configured to supply hydraulic flow from the poppet valve to the stick cylinder without restricting the flow, and when the stick cylinder is extended, the poppet valve is configured to control supply flow rate from the first hydraulic pump to head side oil chamber, the first stick spool valve is configured to control recycled flow rate from a rod side oil chamber to the head side oil chamber, and the second stick spool valve is configured to control the supply flow rate from second hydraulic pump to head side oil chamber and the discharge flow rate from the rod side oil chamber to an oil tank.

DOUBLE CORRECTOR FOR ASYMMETRICAL MECHANISM COMPENSATION

The invention concerns a method for controlling a mechanism () displaying asymmetrical behaviour, the mechanism () comprising a first operating direction (F+) and a second operating direction (F−), the control method making it possible to generate, using a control module () of a computer (), a control signal (x_com) from a setpoint signal (x_cons), in which—when the setpoint signal (x_cons) indicates that the mechanism () should be operated in the first direction (F+), the control module () applies a first corrector () to the setpoint signal (x_cons) in order to generate a control signal (x_com),—when the setpoint signal (x_cons) indicates that the mechanism () should be operated in the second direction (F−), the control module () applies a second corrector () to the setpoint signal (x_cons) in order to generate a control signal (x_com), and in which the first and second correctors () have different parameters (Kp1, Kp2, Ti1, Ti2), in order to compensate for the asymmetrical behaviour of the mechanism (). 2. The method according to claim 1 , wherein one of the first and second correctors associated with one among the first and second directions is which the mechanism reacts slower than in the other direction is a faster corrector than the other corrector.3. The method according to claim 1 , wherein the correctors are proportional-integral correctors.4. The method according to claim 1 , comprising choosing the corrector by using a hysteresis parameter claim 1 , with different thresholds depending on the first and second directions.5. The method according to claim 1 , comprising choosing the corrector depending on a sign of an error signal corresponding to a difference between the setpoint signal and a measurement signal.6. The method according to claim 1 , wherein parameters of the correctors are variable depending on operating points of the mechanism.7. The method according to claim 1 , wherein the mechanism is a valve of a hydraulic circuit of a turbomachine.8. A ...

HYDRAULIC COMPONENT, COMBINATION MADE FROM HYDRAULIC COMPONENTS, AND HYDRAULIC SYSTEM COMPRISING AT LEAST ONE SUCH HYDRAULIC COMPONENT OR COMBINATION

A hydraulic component includes a piston and a cylinder with a piston receiving space in which the piston is displaceably arranged while defining a chamber, via which a pressure may be applied to a first end face of the piston, from a control chamber, via which pressure may be applied to a second end face of the piston which faces away from the first end face. A first hydraulic line and a second hydraulic line open into the chamber and a control line, which branches off from the first hydraulic line, opens into the control chamber. Due to the respective pressure ratio between the pressure in the chamber and the control chamber, the piston is displaceable from a closed position, in which the first and second hydraulic lines are fluidly decoupled, into an open position, in which the first and second hydraulic lines are fluidly connected, and vice versa. 12. A hydraulic component () comprising:{'b': '4', 'a piston (); and'}{'b': 6', '8', '4', '22', '26', '4', '24', '28', '4', '26, 'a cylinder () with a piston receiving space () in which the piston () is displaceably arranged while defining a chamber (), via which a pressure may be applied to a first end face () of the piston (), from a control chamber (), via which pressure may be applied to a second end face () of the piston () which faces away from the first end face (),'}{'b': 30', '32', '22', '34', '30', '24', '22', '24', '4', '30', '32', '30', '32, 'wherein a first hydraulic line () and a second hydraulic line () open into the chamber () and a control line (), which branches off from the first hydraulic line (), opens into the control chamber (), and due to the respective pressure ratio between the pressure in the chamber () and the control chamber (), the piston () is displaceable from a closed position, in which the first and second hydraulic lines (, ) are fluidly decoupled, into an open position, in which the first and second hydraulic lines (, ) are fluidly connected, and vice versa.'}22363424. The hydraulic ...

Method and apparatus for conversion of single-acting pneumatic actuator to electric power platform

An electric-powered fail-safe actuator for use with a valve, where the actuator stores potential energy for conversion to kinetic energy to close or open the valve to the fail-safe position.

Multi Speed Transmission Device with Hydraulically Actuated Shift Rods

A multi-speed transmission with hydraulically actuated shift rods, wherein an actuating pressure (p_B) is applicable by a valve device () and shuttle valves (C to D) to piston chambers (A to B) of pistons ( to ), the actuating pressure being adjustable by valves (). The piston chambers (A to B) can be brought into operative connection with a low-pressure region () by the shuttle valves (C to D) and a prefilling valve () or by the shuttle valves (C to D), the valve device (), and the valves (). Each of the shuttle valves (C to D) has a spring assembly (E to F), by which the shuttle valves (C to D) are held below a pressure threshold of the actuating pressure (p_B) in an operating state that connects the piston chambers (A to B) to the low-pressure region () by the prefilling valve (). 115-. (canceled)16. A multi-speed transmission , comprising;{'b': 7', '11, 'a plurality of hydraulically actuated shift rods ( to );'}{'b': 2', '6', '2', '6', '2', '6', '7', '11, 'a plurality of piston units ( to ) with a plurality of piston chambers (A to B), the plurality of piston units ( to ) configured for adjusting the plurality of hydraulically actuated shift rods ( to ) to change a transmission ratio of the multi-speed transmission;'}{'b': '15', 'a valve device ();'}{'b': 2', '6', '2', '6', '2', '6, 'a plurality of shuttle valves (C to D), each of the shuttle valves (C to D) having a spring assembly (E to F); and'}{'b': 16', '17, 'a plurality of valves (, ),'}{'b': 15', '2', '6', '2', '6', '2', '6', '16', '17', '2', '6', '2', '6', '52', '2', '6', '32', '33', '2', '6', '15', '16', '17, 'wherein an actuating pressure (p_B) is applicable by the valve device () and the shuttle valves (C to D) to the piston chambers (A to B) of the piston units ( to ), the actuating pressure being freely adjustable by the valves (, ), the piston chambers (A to B) of the piston units ( to ) configured to be brought into operative connection with a low-pressure region () either by the shuttle valves (C ...

Controlled float on an agricultural harvester for header leveling

A header assembly for an agricultural harvesting machine comprises a first frame assembly, a second frame assembly that supports a cutter, and is movable relative to the first frame assembly, a float cylinder coupled between the first frame assembly and the second frame assembly, an accumulator, a controllable reservoir, and fluidic circuitry. The fluidic circuitry comprises a first conduit forming a first fluid path that provides a flow of pressurized fluid under pressure to the float cylinder, so the float cylinder exerts a float force on the second frame assembly, a valve mechanism that is actuatable to inhibit fluid flow along the first fluid path between the accumulator and the float cylinder, a second conduit forming a second fluid path fluidically coupled to the controllable reservoir, the controllable reservoir being controllable to add fluid to the float cylinder.

Work Machine

A connection switching device () connects a bottom-side oil chamber (C) of a boom cylinder () and a bottom-side oil chamber (C) of an arm cylinder () when a boom operating device (A) instructs the contraction of the boom cylinder () and an arm operating device (B) instructs the expansion of the arm cylinder (). The connection switching device () connects the bottom-side oil chamber (C) of the boom cylinder () and a rod-side oil chamber (D) of the arm cylinder () when the boom operating device (A) instructs the contraction of the boom cylinder () and the arm operating device (B) instructs the contraction of the arm cylinder (). 14.-. (canceled)5. A work machine comprising:a front mechanism which is configured to include a boom, a boom cylinder which drives the boom, a first working member, a first working member driving cylinder which drives the first working member, a second working member, and a second working member driving cylinder which drives the second working member,a hydraulic pump which is configured to supply a hydraulic oil to the boom cylinder and the first working member driving cylinder and the second working member driving cylinder,a boom operating device which is configured to instruct the operation of the boom cylinder,a first working member operating device which is configured to instruct the operation of the first working member driving cylinder,a second working member operating device which is configured to instruct the operation of the second working member driving cylinder,a boom directional control valve which is configured to switch flow direction of the hydraulic oil supplied from the hydraulic pump to the boom cylinder in response to the instruction from the boom operating device,a first working member directional control valve which is configured to switch flow direction of the hydraulic oil supplied from the hydraulic pump to the first working member driving cylinder in response to the instruction from the first working member operating ...

Construction Machine

To provide a construction machine that has a hydraulic system mounted thereon in which a closed-circuit pump, and an open-circuit pump and a proportional valve are arranged as a pair, and that makes it possible to use an unused open-circuit pump or proportional valve to accelerate the speed of a single rod hydraulic cylinder when the single rod hydraulic cylinder and a hydraulic motor are driven simultaneously. A controller () controls a cap-side selector valve () and a rod-side selector valve () such that a particular open-circuit pump () not connected to a single rod hydraulic cylinder () is connected to the single rod hydraulic cylinder, and controls an opening area of a particular proportional valve () provided on a flow line that connects a delivery port of the particular open-circuit pump to a tank, when the single rod hydraulic cylinder and a hydraulic motor () are driven simultaneously. 1. A construction machine comprising:a tank that stores hydraulic operating fluid;a plurality of closed-circuit pumps including bidirectionally-tiltable hydraulic pumps;a plurality of open-circuit pumps including unidirectionally-tiltable hydraulic pumps, the number of the unidirectionally-tiltable hydraulic pumps being same as the number of the plurality of closed-circuit pumps;a plurality of hydraulic actuators including at least one single rod hydraulic cylinder, and at least one hydraulic motor;an operation device for giving an instruction about operation of the plurality of hydraulic actuators;a plurality of closed-circuit selector valves that connect the plurality of closed-circuit pumps to the plurality of hydraulic actuators such that closed circuits are formed;a plurality of cap-side selector valves that connect delivery ports of the plurality of open-circuit pumps to a cap chamber of the single rod hydraulic cylinder;a plurality of proportional valves that are provided on flow lines that connect the delivery ports of the plurality of open-circuit pumps to the tank;a ...

Hydraulic circuit for controlling a movable component

Hydraulic circuits for controlling a movable component use one or more of a plurality of fluid supplies. Pressurized fluid flowing from one supply is routed toward the component and is not inadvertently vented into another fluid supply, or into an exit port. A backflow path is provided for fluid returning from the hydraulic component when the component is actuated in a reversed direction. The hydraulic circuits can be used, for example, on blowout preventers in a subsea environment.

SYSTEM FOR HYDRAULIC PRESSURE RELIEF VALVE OPERATION

A hydraulic power unit (HPU) configured for use with a pressure relief valve (PRV) having an open port and a close port is provided. The HPU includes a pneumatic primary pump, a hydraulic fluid reservoir, an accumulator, and a two position solenoid directional valve (TPSDV). The hydraulic fluid reservoir is in fluid communication with the primary pump. The TPSDV is in communication with the primary pump, the reservoir, the accumulator. The TPSDV is configured for fluid communication with the PRV. The HPU is configurable in a PRV fail open configuration and a PRV fail close configuration. 1. A hydraulic power unit (HPU) configured for use with a pressure relief valve (PRV) having an open port and a close port , the HPU comprising:a pneumatic primary pump;a hydraulic fluid reservoir in fluid communication with the primary pump;an accumulator; anda two position solenoid directional valve (TPSDV) in communication with the primary pump, the reservoir, the accumulator, and the TPSDV is configured for fluid communication with the PRV;wherein the HPU is configurable in a PRV fail open configuration and a PRV fail close configuration.2. The HPU of claim 1 , wherein in the PRV fail close configuration claim 1 , the HPU is configured to provide hydraulic fluid at an elevated pressure to the close port of the PRV claim 1 , which elevated pressure is adequate to maintain the PRV in a closed configuration.3. The HPU of claim 2 , further comprising:at least one first fluid line providing fluid communication between the TPSDV and the close port of the PRV;at least one second fluid line providing fluid communication between the TPSDV and the open port of the PRV; andat least one valve in fluid communication with the at least one second fluid line;wherein the at least one valve is configured so that fluid flow from the open port of the PRV is restricted.4. The HPU of claim 3 , wherein the at least one valve includes at least one fluid flow restriction valve and at least one fluid ...

Hydraulic Control Module and Solenoid Assembly Included Therein

A solenoid assembly includes a solenoid adapted to be coupled to a solenoid connecting member, with the solenoid connecting member extending from a support member. The solenoid assembly also includes a retaining bracket having a body portion and a securing portion extending from the body portion. The body portion is adapted to be removably coupled to the solenoid connecting member, and the securing portion is removably coupled to the solenoid. The retaining bracket is moveable between an unsecured position, and a secured position. The securing portion of the retaining bracket provides a spring force to the solenoid when the retaining bracket is in the secured position such that the solenoid is biased toward the solenoid connecting member to secure the solenoid between the solenoid connecting member and the securing portion of the retaining bracket.

Valve Arrangement for the Hydraulic Circuit of a Work Machine

Valve arrangement includes a pilot operated load control valve fluidly having an energized unidirectional state allowing hydraulic fluid to pass from an outlet to an inlet and a de-energized unidirectional state allowing hydraulic fluid to pass from the inlet to the outlet. A pilot conduit is configured to direct pilot hydraulic fluid to actuate the load control valve. A connecting conduit fluidly connects the pilot conduit to the inlet, the connecting conduit including a flow restriction and a check valve configured to allow hydraulic fluid to flow only in a direction from the pilot conduit towards the inlet. 1. A valve arrangement for a hydraulic system for raising and lowering a component of a work machine , comprising:an inlet and an outlet;a pilot operated load control valve fluidly connected between the inlet and the outlet, the load control valve having an energized unidirectional state allowing hydraulic fluid to pass from the outlet to the inlet and a de-energized unidirectional state allowing hydraulic fluid to pass from the inlet to the outlet;a pilot conduit configured to direct pilot hydraulic fluid to actuate the load control valve; anda connecting conduit fluidly connecting the pilot conduit to the inlet, the connecting conduit comprising a flow restriction and a check valve configured to allow hydraulic fluid to flow only in a direction from the pilot conduit towards the inlet.2. A valve arrangement according to claim 1 , wherein the flow restriction in the connecting conduit is an orifice.3. A valve arrangement according to claim 1 , wherein the pilot conduit comprises a flow restriction.4. A valve arrangement according to claim 3 , wherein the flow restriction in the pilot conduit is an orifice.5. A valve arrangement according to claim 1 , further comprising a relief valve connected between the inlet and the outlet in parallel with the load control valve.6. A hydraulic system with component failure protection comprising:a hydraulic fluid source;a ...

Reversible Flow Path Construction

A flow control manifold that routes pressurized fluid from one of a first fluid manifold connection and a second fluid manifold connection of the flow control manifold to an input of a work tool and directs return fluid from an outlet of the work tool to the other of the first and second fluid manifold connections not receiving pressurized fluid. 1. A flow control manifold for connecting a work tool to a work machine , comprising:a first fluid manifold connection and a second fluid manifold connection, the first and second fluid manifold connections in fluid communication with the work machine;an input configured to supply pressurized fluid from the work machine to the work tool and an outlet configured to receive return fluid from the work tool;a first passage fluidly connecting the first fluid manifold connection to the input and conveying pressurized fluid therethrough, the first passage comprising a first check valve that opens in the direction of the input;a second passage fluidly connecting the outlet to the second fluid manifold connection and conveying return fluid therethrough, the second passage comprising a second check valve that opens in the direction of the second fluid manifold connection;a third passage fluidly connecting the second fluid manifold connection to the input and conveying pressurized fluid therethrough, the third passage comprising a directional control valve that opens to permit fluid to flow through the third passage in response to the presence of the pressurized fluid in the third passage and comprising a third check valve that opens in the direction of the input; anda fourth passage fluidly connecting the outlet to the first fluid manifold connection and conveying return fluid therethrough, the fourth passage comprising a fourth check valve that opens in the direction of the first fluid manifold connection.2. The flow control manifold of claim 1 , wherein the first and third passages include a standard orifice adjacent the input.3. ...

HYDRAULIC DRIVE APPARATUS FOR CONSTRUCTION MACHINE

Provided is a hydraulic drive apparatus for a construction machine capable of achieving both of cavitation prevention and improvement of regeneration efficiency. The apparatus includes a regenerative motor configured to regenerate energy of hydraulic fluid discharged from a slewing motor, a first regeneration tank line for returning regeneration discharge fluid from the regenerative motor to a tank through a back pressure valve which is provided in a makeup line, a second regeneration tank line for returning the regeneration discharge fluid directly to the tank so as to bypass the back pressure valve, a regeneration-tank-line selector valve, and a regeneration-tank-line-selection control section configured to shift the regeneration-tank-line selector valve to pass the regeneration discharge fluid through the first regeneration tank line during slewing deceleration and otherwise through the second regeneration tank line. 1. A hydraulic drive apparatus provided in a construction machine including an upper slewing body capable of slewing , the hydraulic drive apparatus comprising:a plurality of hydraulic actuators including a slewing motor that slews the upper slewing body;a hydraulic pump configured to discharge hydraulic fluid for moving the hydraulic actuators;a regenerative motor driven by a part of the hydraulic fluid discharged from the hydraulic actuators to perform regenerative action;a hydraulic brake circuit including a relief valve and configured to perform anti-cavitation action for returning the hydraulic fluid on a meter-out side of the slewing motor to a meter-in side during deceleration of slewing of the upper slewing body to prevent cavitation from occurrence and to perform hydraulic brake action by the relief valve;a makeup line connecting the hydraulic brake circuit to a tank;a back pressure valve provided in the makeup line and configured to generate back pressure in the makeup line;a first regeneration tank line for returning regeneration discharge ...

Construction Machine

A controller sets a target flow rate of a regenerative hydraulic motor at zero or a low flow rate within an extent in which hydraulic pressure in a regeneration hydraulic line does not become negative pressure when a detected pressure PS detected by a pressure sensor is lower than a first set value previously set by overload relief valves, sets the target flow rate of the regenerative hydraulic motor at a value corresponding to the detected pressure when the detected pressure is higher than or equal to the first set value, and controls the revolution speed of a generator/motor in such a manner that a flow rate through the regenerative hydraulic motor equals the target flow rate. With such features, excellent operability equivalent to that in the conventional technology can be secured. 1. A construction machine comprising:a swing structure;a swing hydraulic motor that rotationally drives the swing structure;a regeneration device including a regeneration hydraulic line connected to a pair of actuator hydraulic lines for supplying and discharging hydraulic fluid for the swing hydraulic motor, a regenerative hydraulic motor connected to the regeneration hydraulic line, and a generator/motor that rotates together with the regenerative hydraulic motor;a pressure detection device capable of detecting at least a pressure on a high-pressure side of the pair of actuator hydraulic lines;overload relief valves connected to the actuator hydraulic lines; anda control unit that sets a target flow rate of the regenerative hydraulic motor at zero or a low flow rate within an extent in which hydraulic pressure in the regeneration hydraulic line does not become negative pressure when the detected pressure on the high-pressure side of the pair of actuator hydraulic lines detected by the pressure detection device is lower than a first set value previously set by the overload relief valves, sets the target flow rate of the regenerative hydraulic motor at a value corresponding to the ...

Electric Excavator

An excavator with a boom comprises a main electrical drive system with an electrical power storage unit. The excavator comprises an electrical drive configured to actuate movement of the boom to raise and/or lower part of the boom. The excavator comprises a separate fluid-operated, auxiliary actuation system for storing potential energy of the part of the boom during lowering thereof and for using the stored potential energy to support raising of the part of the boom. The auxiliary actuation system is configured to store the potential energy and to support raising the part of the boom autonomously without interaction with the main electrical drive system. 1. An excavator including a boom , comprising:a main electrical drive system including an electrical power storage unit and an electrical drive configured to actuate movement of the boom to raise and/or lower part of the boom with a pivoting movement; anda separate fluid-operated auxiliary actuation system for storing potential energy of the part of the boom during lowering thereof and for using the stored potential energy to support raising of the part of the boom, wherein the auxiliary actuation system is configured to store the potential energy and to support raising the part of the boom autonomously without interaction with the main electrical drive system.2. The excavator according to claim 1 , wherein the auxiliary actuation system comprises an auxiliary actuator coupled to the boom and at least one accumulator claim 1 , and wherein the auxiliary actuator and the at least one accumulator are coupled such that lowering of the part of the boom pressurizes the at least one accumulator and such that raising of the part of the boom is supported by potential energy stored in the at least one accumulator.3. The excavator according to claim 2 , further comprising a main hydraulic system including a hydraulic actuator for moving the part of the boom and a hydraulic pump for actuating the hydraulic actuator claim 2 , ...

VALVE SYSTEM FOR PNEUMATIC CYLINDERS

A valve system for use with a cylinder having an extensible rod, includes first and second valve assemblies, each including an inlet/outlet port configured to selectively be coupled with a source of pressurized gas, a check valve biased toward a closed state and having a check valve body at least partially receivable within a first port of the cylinder, a flow control valve positioned in series between the inlet/outlet port and the check valve, and an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas. First and second pilot lines extend to the respective inlet pilot ports from respective outlet pilot ports of the opposite ones of the first and second valve assemblies. When pressurized gas is supplied to the inlet/outlet port of a valve assembly, pressurized gas is also supplied to the opposite inlet pilot port. 1. A valve system for use with a double-acting cylinder having an extensible and retractable rod and opposing first and second cylinder ports , the valve system comprising: an inlet/outlet port configured to selectively be coupled with a source of pressurized gas,', 'a check valve biased toward a closed state and having a check valve body defining a cylinder connection port of the first valve assembly that is at least partially receivable within the first cylinder port,', 'a flow control valve positioned in series between the inlet/outlet port and the check valve, and', 'an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas;, 'a first valve assembly including'} an inlet/outlet port configured to selectively be coupled with a source of pressurized gas,', 'a check valve biased toward a closed state and having a check valve body defining a cylinder connection port of the second valve assembly that is at least partially receivable within the second cylinder port,', 'a flow control valve positioned in the second valve assembly in series between ...

HYDRAULIC CONTROL VALVE

A new means of achieving a valve float position in a closed centered hydraulic control valve. The valve has a main spool position whereby pressure compensator load sense control pressure is drained to tank through the main spool. Secondly, a pin acts on the pressure compensator to prevent the main pump flow from reaching the main section spool. Finally, the new spool position adds a connection from the consumer to tank, enabling a float position. 1. A pressure compensated hydraulic control valve comprising:a pair of consumer workports for attachment to a hydraulic implement;a pump port for attachment to a variable displacement pump;a tank port for attachment to a hydraulic fluid tank; a neutral spool position in which the pressure compensated pump flow channel is blocked and the variable displacement pump load sense channel is connected to the tank channel,', 'a first power position connecting the pressure compensated pump flow channel to a first one of the pair of consumer workports, connecting the first one of the pair of consumer workports to the variable displacement pump load sense channel, and connecting a second one of the pair of consumer workports to the tank channel,', 'a second power position connecting the pressure compensated pump flow channel to the second one of the pair of consumer workports, connecting the second one of the pair of consumer workports to the variable displacement pump load sense channel, and connecting the first one of the pair of consumer workports to the tank channel, and', 'a fourth spool position connecting both of the pressure compensated pump flow channel and the tank channel to both of the pair of consumer workports, the fourth spool position further connecting the variable displacement pump load sense channel to the tank channel;, 'a main valve spool including passages to selectively connect a pressure compensated pump flow channel from the pump port, a tank channel to the tank port, a variable displacement pump load sense ...

HYDRAULIC SYSTEM FOR AN AGRICULTURAL IMPLEMENT INCORPORATING IMPLEMENT-BASED HYDRAULIC LOAD SENSING

A hydraulic system includes a supply line, at least one implement-based control valve, an implement-based pressure regulating valve, and a load sensing circuit. The implement-based control valve(s) is fluidly coupled to the supply line and configured to regulate a flow of the pressurized hydraulic fluid supplied through at least one downstream actuator line to at least one hydraulic actuator of the implement. The implement-based pressure regulating valve is fluidly coupled to the supply line upstream of the control valve(s) and configured to regulate a fluid pressure to be equal to or greater than a minimum fluid pressure. The load sensing circuit is fluidly coupled to the pressure regulating valve and provides a line or load pressure to the pressure regulating valve. The pressure regulating valve is configured to regulate the supply of the pressurized hydraulic fluid based on the line pressure. 1. A hydraulic system for regulating the pressure of hydraulic fluid supplied to actuators of an agricultural implement , the hydraulic system comprising:a supply line configured to receive pressurized hydraulic fluid from a fluid source;at least one implement-based control valve fluidly coupled to the supply line, the at least one control valve configured to regulate a flow of the pressurized hydraulic fluid received from the supply line and supplied through at least one downstream actuator line to at least one hydraulic actuator of the implement;an implement-based pressure regulating valve fluidly coupled to the supply line upstream of the at least one control valve, the pressure regulating valve being configured to regulate a fluid pressure of the pressurized hydraulic fluid supplied to the at least one control valve through the supply line such that the fluid pressure is equal to or greater than a minimum fluid pressure; anda load sensing circuit fluidly coupled to the pressure regulating valve, the load sensing circuit providing a line pressure associated with the at ...

Electric hydraulic actuation system for a safety critical application

An actuation system for a component has a plurality of cylinders. A piston is in operable communication with each of the cylinders and is configured to move at least a portion of the component to a desired position. A plurality of pumps are in fluidic communication with the plurality of cylinders, and are each driven by electric motors. The number of pumps is less than a number of cylinders.

Hydraulic Control System of Leveling Oil Cylinder of Loading Head

The invention discloses a hydraulic control system of a leveling hydraulic cylinder of a loading head, characterized by comprising a hydraulic pump, a two-position three-way electronic control reversing valve, a three-position four-way electronic control reversing valve, a three-position four-way cam valve and a hydraulic cylinder. The invention not only can perform leveling by using the electric control system, but also comprises the hydraulic cam valve controlling the hydraulic cylinder for self-leveling, and the two leveling manners can be independently used or switched mutually, thus achieving a better leveling effect. 1. A hydraulic control system of a leveling hydraulic cylinder of a loading head , comprising a hydraulic pump , a two-position three-way electronic control reversing valve , a three-position four-way electronic control reversing valve , a three-position four-way cam valve and a hydraulic cylinder; wherein:an oil inlet of the two-position three-way electronic control reversing valve is connected with the hydraulic pump, one oil outlet of the two-position three-way electronic control reversing valve is connected with an oil outlet of the three-position four-way electronic control reversing valve, and the other oil outlet of the two-position three-way electronic control reversing valve is connected with an oil inlet of the three-position four-way cam valve;two oil outlets of the three-position four-way electronic control reversing valve are respectively connected to a front oil port and a rear oil port of the hydraulic cylinder after passing through a hydraulic lock;two oil outlets of the three-position four-way cam valve are also respectively connected to the front oil port and the rear oil port of the hydraulic cylinder by the hydraulic lock.2. The hydraulic control system of the leveling oil hydraulic cylinder of the loading head of claim 1 , wherein an overflow valve is arranged on an oil line between the hydraulic pump and the two-position ...

HYDRAULIC BALANCING CONTROL VALVE AND RIDE CONTROL SYSTEM INCORPORATNG SAME

A balancing valve includes four ports. While the pressures at a pair of balancing ports of a hydraulic balancing valve are equal, the valve maintains two other ports in a closed position. Upon a pressure differential between the balancing ports, fluid communication can occur between one of the balancing ports and either of the other ports based upon the direction of the pressure differential. A hydraulic ride control system utilizes the balancing valve together with other control valves to provide ride control functionality. 1. A hydraulic balancing valve , comprising:a body, the body defining a bore, a charge port, a pump port, a tank port, and a control port, each of the charge port, the pump port, the tank port, and the control port being in fluid communication with the bore; a first position in which the charge port and the tank port are in fluid communication with each other and the charge port and the pump port are in fluid isolation from each other,', 'a second position in which the charge port, the tank port, and the pump port are in fluid isolation from each other, and', 'a third positon in which the charge port and the pump port are in fluid communication with each other and the charge port and the tank port are in fluid isolation from each other; and, 'a spool, the spool being movably disposed within the bore for directing hydraulic fluid between the charge port and the pump port and between the charge port and the tank port, the spool including a first pressure surface in fluid communication with the charge port and a second pressure surface in fluid communication with the control port, the first and second pressure surfaces facing in opposing relationship to each other, the spool being movable within the bore betweena biasing member, the biasing member operatively connected to the body and spool to bias the spool to the second position and configured to permit movement of the spool to the first position upon a first pressure differential between the ...