REFRIGERATION COMPRESSOR

[0001] The invention relates to a refrigerant compressor having a, preferably hermetically sealable, compressor stator; an electric drive unit comprising a rotor and a stator; a rotatably connected with the rotor, having a longitudinal axis and a crankshaft driven piston-cylinder unit from the crankshaft, wherein the electric drive unit is constructed as an external rotor motor and the rotor at least in portions radially outwardly extending support element has a longitudinal axis and the carrier element is attached fixed against rotation to the crankshaft.

[0002] Refrigerant compressor, particularly hermetically enclosed refrigerant compressor, has long been aware and come predominantly in refrigerating cabinets, such as refrigerators or - shelves, for use. The refrigerant process as such is also known for a long time. This energy absorption from the space to be cooled by refrigerant is heated by the refrigerant in an evaporator and finally superheated and compressor, also called refrigerant compressor, pumped through a piston-cylinder unit by a piston moving in a cylinder housing to a higher pressure level translation, where the refrigerant heat and delivers a capacitor via a throttle, a pressure reduction and the cooling of the refrigerant occurs in the, is conveyed back into the evaporator. The movement of the piston is realized through a crank drive comprising a crankshaft driven by an electric drive unit.

[0003] The electric drive unit comprises a stator formed as an external rotor motor, usually of a laminated core and wire windings is formed, and radially inwardly relative to the longitudinal axis, i.e. closer to the crankshaft, is. The drive unit further comprises a rotor, the stator relative to the longitudinal axis disposed outside and around outside at least in sections. A carrier element is used as a connection between the electromagnetic components of the rotor, for example distributed over the circumference, a short ring interconnected by permanent magnets, and the crank drive, in particular of the crankshaft. The carrier element is fixed against rotation, therefore - shape, friction or integrally with the crank drive, in particular with the crankshaft, connected, to drive the crank mechanism by the electromagnetic interaction between the rotor and stator during operation. The carrier element is typically connected with one of the piston-cylinder unit and extending from the end section of the crankshaft based on the crankshaft longitudinal axis radially outwardly. In other words the carrier element is connected to a free, remote from the piston-cylinder unit portion of the crankshaft, the crankshaft mounted in a bearing bush is much during. The carrier element is arranged in the stator or the carrier element normally engages under the oil sump and the oil sump between the facing side of the stator.

[0004] The drive unit is usually formed either as an asynchronous motor, wherein the stator comprises a laminated core and/or copper or aluminum wire windings and the rotor comprises a stack of plates and - aluminum with aluminum shorting rings comprises webs, or formed as a synchronous motor, wherein the stator comprises a laminated core and/or copper or aluminum wire windings and the rotor comprises a plurality of permanent magnets.

[0005] The piston-cylinder unit and the crank drive, in particular the crankshaft, to lubricate during operation, is provided a lubricant conveyor system, by means of which during operation of the refrigerant compressor in a bottom portion of said lubricant from a lubricant sump in the direction of the compressor housing forming during operating piston-cylinder unit is promoted.

[0006] The lubricant conveyor system is generally self-formed at least partially through the crank shaft, wherein the crankshaft at the opposite end of the piston-cylinder unit, preferably on an end face of the crankshaft, at least one axial bore and/or an eccentric bore, because of centrifugal force during rotation of the crankshaft through which lubricant in the direction of the piston-cylinder unit is promoted. Additionally or alternatively the crankshaft has a helical groove formed in a central portion on the circumferential surface often, promotes lubricant on the circumferential surface of the axial bore and/or upwardly and connected to the eccentric bore is.

[0007]Adisadvantage of the prior art is expressed, that is to be overcome by the delivery head of the lubricant, in particular during tapping of the lubricant from the lubricant sump, the entire capacity of the lubricant delivery system is reduced. This reduction of the capacity decreasing with increasing transfer height resulting from the quantity of lubricant can be conveyed by means of a centrifugal force based on the promotion.

[0008] It is therefore a task of the invention to overcome the disadvantages of the state of charge of a refrigerant compressor and the technique as an external rotor motor with a drive unit formed to propose, increasing feed of lubricant from a lubricant sump of a preferably less or reduced overall height of the compressor allows.

[0009] Lubricant in parallel to a longitudinal axis of the crankshaft or inclined to a longitudinal axis extending bore, preferably an eccentric bore arranged eccentrically to the longitudinal axis, the crankshaft introduce, without the end of the crankshaft opposite the piston-cylinder unit far over the rotor and the piston-cylinder unit projects without the opposite end of the crankshaft in the lubricant sump dips, is a sleeve-shaped lubricant receiving the crankshaft itself but not rotatably attached on the carrier element. By the attachment of the lubricant receiving said support member rotates together with the crankshaft in the lubricant receiving operating state, since the carrier element itself is non-rotatably connected to the crankshaft.

[0010] The sleeve-shaped lubricant receiving dips into the oil sump in the operating state a, wherein lubricant, for example via a lubricant inlet opening, into the lubricant receiving can enter. The lubricant receiving conventional manner is made of a metallic material or from a plastic. By the sleeve form of lubricant receiving, therefore the training can be received as a hollow body in the lubricant of the lubricant receiving, by centrifugal force in the lubricant receiving lubricant located pressed against the inner wall of the lubricant receiving, whereby the pressure increases in the direction of the end of the crankshaft is promoted and the lubricant. This forms a lubricant within the lubricant receiving typically parabola or a paraboloidal shaped lubricant column.

[0011] By the connection of the lubricant receiving on the carrier element is not more necessary, that the crankshaft must protrude above said support member, the projecting portion to be fixed to the lubricant receiving order. The delivery head of the lubricant can be lowered by this measure, leading to an increase in the capacity of the lubricant conveyor system. In other words the conveyed lubricant amount based on a period with the novel connection of the lubricant receiving to the support element is higher than a conventional connection of the lubricant receiving to a projecting end of the crankshaft above said support member.

[0012] By the higher capacity at lower speeds may also be a sufficient lubrication of the piston-cylinder unit ensure, as far as possible so that the refrigeration compressor operable energy optimized center.

[0013] According to the invention is therefore provided, on a side facing away from the piston-cylinder unit that a sleeve-shaped of the carrier element for promotion of lubricant from a lubricant receiving zentrifugischen in a floor portion of lubricant sump formed in the direction of the compressor housing piston-cylinder unit is provided, wherein the sleeve-shaped lubricant receiving on the carrier element is connected in a rotationally fixed manner.

[0014] Rotatably attached under I mean, that the lubricant receiving during operation of the refrigerant compressor and rotates together with the crankshaft not relative movement between lubricant receiving and crankshaft occurs. This kinematic connection can be achieved by one hand, and support member are separate components that lubricant receiving and lubricant receiving rotation, therefore - shape, friction or material, secured to the supporting structure. On the other hand the rotationally fixed connection may also be achieve, if carrier element and lubricant receiving are integrally formed.

[0015] In one design variant of the invention, that the support element extending coaxially to the longitudinal axis a, central through opening, wherein the sleeve-shaped lubricant receiving a separate component and a fastening portion of the sleeve in the region of the passage opening is on the carrier element is fixed lubricant receiving. Since represent separate components and lubricant receiving support member, the sleeve-shaped lubricant receiving has a, also usually tubular, fixing portion, via which the lubricant receiving rotatably mounted on the carrier element, so - shape, friction or integrally, .

[0016] The fastening of the fastening portion of the sleeve-shaped lubricant receiving in the region of the passage opening of the lubricant receiving enables effective delivering the lubricant into the bore extending parallel to a longitudinal axis of the crankshaft or inclined to the longitudinal axis, preferably the eccentric bore arranged eccentrically to the longitudinal axis, of the crankshaft.

[0017] The quality of the fixed connection of the carrier element on the crankshaft to improve, in a further embodiment of the invention is provided, that the through opening of the carrier element for the connection of the crankshaft a sleeve-shaped extension is formed. The crankshaft can be either received by the sleeve-shaped extension of the carrier element on which the piston-cylinder unit have formed through hole or end remote from the recess, preferably a bore,, which is received in the sleeve-shaped extension. By the sleeve-shaped extension, which is preferably formed integrally with the support member, the contact surface between crankshaft and strong support element increases, the wall thickness of the support element must be increased without also. The enlarged contact surface by a greater friction force is achieved.

[0018]Aparticularly cost-effective production of the support element together with a sleeve-like extension in a further embodiment of the invention can be achieved by, that the sleeve-shaped extension from the carrier element is formed by a forming operation. For example the sleeve-shaped extension of the carrier element as by a protuberance of the carrier element can be produced - bending or deep produced.

[0019]Apreferred embodiment of the invention refrigerant compressor provides, that the sleeve-shaped extension on the opposite side of the carrier element of the piston-cylinder unit extends, a portion of the crankshaft is rotatably connected to the through-hole and the fastening portion of the sleeve-shaped lubricant receiving at a, relative to the longitudinal axis, of the sleeve-shaped extension outer surface is fixed. In the mounted state a portion of the crankshaft, preferably the end portion of the crankshaft is remote from the piston-cylinder unit, received in the through hole of the support member and non-rotatably connected. Characterized in that the crankshaft is rotationally fixed, for example - or force frictionally, connected to the carrier element.

[0020] The carrier element can for example be shrunk or pressed on the crankshaft. As the sleeve-shaped extension, the forms the, preferably cylindrical, extends through opening, into which the piston-cylinder unit opposite direction, in other words in the direction of the bottom portion of the compressor housing so, it lends itself particularly for receiving the attachment portion of the lubricant receiving. Because of the shape of the projection sleeves of the carrier element in a simple manner the sleeve-like fastening portion of the lubricant receiving bonding to the sleeve-shaped extension of the carrier element can be. The lubricant receiving externally on the sleeve-shaped extension is pushed in and connected rotationally fast to friction, preferably force -, - or positively, with the sleeve-shaped extension of the carrier element. The attachment section can for example be shrunk or pressed onto the sleeve-shaped extension.

[0021] The surface pressure between the mounting portion of the lubricant receiving, particularly an inner surface of the mounting portion, and the outer surface of the sleeve-shaped extension of the carrier element and thus to increase the holding force of the mounting portion with the support member to increase, in a further particularly preferred embodiment variant of the invention is provided, relative to the longitudinal axis that a radially outwardly extending, annular support member surrounding at least a portion of the mounting portion of the sleeve-shaped lubricant receiving. By the radial extension of the supporting ring, i.e. in other words by the wall thickness of the annular support member, this has a high rigidity, which prevents deformation of the mounting portion from the sleeve-shaped extension of the carrier element and releasing said lubricant receiving. Another effect of the annular support member is, the fact that the seat of the support member and the holding force on the crankshaft by the increased stiffness or the elevated surface pressure improved.

[0022] According to a further preferred embodiment variant of the invention refrigerant compressor is provided, the fastening portion of the sleeve that is formed at least in sections from the annular lubricant receiving support element. If annular support member and lubricant receiving are formed integrally, so the support element of the mounting portion is formed as a cross-sectional enlargement, the mounting of the lubricant receiving is facilitated, since the support member need not be mounted separately. At the same time the rigidity of the mounting portion is increased by the support element, the support element is improved so that the holding force of the lubricant receiving and releasing said lubricant receiving more difficult or prevented from the support member.

[0023] In a further preferred embodiment variant of the invention, the annular support member on the mounting portion of the sleeve-shaped lubricant receiving that is shrunk or pressed. The shrunk or pressed radially inwardly toward the longitudinal axis of annular support member exerts a force on an outer peripheral surface of the mounting portion of the lubricant receiving directed, so that the clamping force or the resulting surface pressure is increased. Both in the rotationally fixed, or non-positive connection of the fixing portion to the sleeve-shaped extension - friction of the carrier element and the rotationally fixed, or non-positive connection of the support element is ensured to the crankshaft - friction.

[0024] According to a further particularly preferred embodiment variant of the invention, that a fastening portion of the sleeve-shaped lubricant receiving parallel to the longitudinal axis and the attachment sleeve-type lubricant receiving a subsequent, radially outwardly extending collar section longitudinal axis, wherein the collar portion preferably rests on the support element. The fastening portion of the lubricant housing extends parallel to the longitudinal axis, in other words a circular cylindrical sleeve therefore forms, to enable simple mounting. The collar portion prevents, that the lubricant receiving in the axial direction, i.e. parallel to the longitudinal axis shifts, . Preferably the displacement is prevented by the collar portion abuts the support member.

[0025] Can also simultaneously as a stop for the collar portion mounting the lubricant receiving serve.

[0026] An alternative embodiment variant of the invention provides, that the sleeve-shaped extension on the facing side of the support element of the piston-cylinder unit extends, wherein the sleeve-shaped extension is non-rotatably connected to said crankshaft and that the fastening portion of the sleeve-shaped lubricant receiving in the by the sleeve-shaped extension formed through hole is rotationally fixedly held. This design variant is distinguished by a particularly compact structure, since the fastening portion of the lubricant receiving is not pushed into the passage outside but inserted, preferably pressed.

[0027] In the end face of the piston-cylinder unit can end facing away from the crankshaft have a recess, into which the sleeve-shaped extension of the carrier element is pressed, the rotationally fixed connection between carrier element and produce crankshaft.

[0028] As already mentioned, is also the integral execution of sleeve-shaped lubricant receiving and supporting element is a rotationally fixed connection is. In a further alternative embodiment variant of the invention is therefore provided, sleeve-type lubricant receiving and the carrier element are formed in one piece, wherein the lubricant receiving is formed by means of a forming operation from the carrier element and the piston-cylinder unit that is fixedly retained in the sleeve-like lubricant receiving end is remote from the crankshaft. Lubricant receiving and supporting element are produced from a plate-shaped blank can be supplied by a deep drawing process. The end of the crankshaft in the lubricant receiving to maintain rotation, the carrier element can be pressed onto the crankshaft or shrunk. The assembly is further simplified due to the integrally formed therewith, since the separate mounting deletes the lubricant receiving.

[0029] The invention is now explained in more detail with reference to embodiments. The drawings are exemplary and the present invention should although idea, but it not concentrating or even finally reproducing.

[0030] It showed:

[0031]Asectional view of a first embodiment of a refrigeration compressor 1 figfig. invention;

[0032] Figfig. an enlarged detail view of a bottom portion of said refrigerant compressor 2 figfig. according 1;

[0033] 3 A sectional representation of a bottom portion of a second design variant figfig. the invention refrigerant compressor.

[0034] Figures 1 and 2 show a first embodiment of the invention formed as an external rotor with a refrigerant compressor drive unit, which is arranged inside a compressor housing can be hermetically capsule 6. The drive unit comprises a stator and a rotor to stator and rotor 4 3 3 4th centrally having a longitudinal axis 2 is a crankshaft arranged 1, which crankshaft 1 rotary testing, for example - shape, friction or integrally, with a support member 12 of the rotor 4 is connected, a cyclically compressing refrigerant to the refrigerant compressor piston-cylinder unit 5 drive. The crankshaft 1 is in a bearing bush 17 of a piston-cylinder unit 5 mounted support carrying housing 18. On the outside of the bearing sleeve 17 is fixed to the stator 3, which in a radial direction relative to the longitudinal axis 2, also referred to as sequence in the radial direction, is disposed inside.

[0035] The crankshaft 1 is part of a crank mechanism, which crank drive an eccentrically offset longitudinal axis 2 and connected directly with the crankshaft has crank pin 26 1. The piston-cylinder unit 5 comprises a piston which is guided linearly movable in a cylinder housing 25 24, a connecting rod connecting the piston 25 with the crank pin 26 23, valves 27 and a cylinder head assembly comprising a head assembly connected to the cylinder 27 suction sound damper 28.

[0036] In the present embodiment are the support housing 18 and the cylinder housing 24 integrally, more precisely as a casting, formed. The support housing has several extensions on 18, via which the support housing in a bottom portion of the compressor housing 6 7 18 to 21 is mounted in the compressor housing 6 spring elements. In alternative execution variants can support housing 18 and cylinder housing 24 be in two pieces and be linked together by connection means.

[0037] The rotor 4 comprises, as shown in Figure 2 represented, a plurality of permanent magnets which are arranged radially outside the stator 14 and 15 a short ring 3 are connected with each other in the circumferential direction. The permanent magnets 14 with the crankshaft 1 by means of frictional force - or rotationally fixed to connecting, the rotor extending radially from the crankshaft 4 comprises outwardly extending support member 1 12, which engages under the stator 3. The carrier element 12 is substantially cup-shaped and has a raised, curved edge portion in the direction of the piston-cylinder unit 5, on which the permanent magnets 14 and the short circuit ring 15 are fixed.

[0038] For connection to the crankshaft 1 has a centrally arranged on the carrier element 12 through opening 13, around the rotor 4 coaxially to the longitudinal axis to position 2. The support member 12 in the present embodiments has a sleeve-shaped extension 19 having a circular cylindrical light cross section, which is located centrally and is remote from the piston-cylinder unit 5 on the side of the carrier element 12 extends. The through hole 13 is formed here by the extension 19. Support member 12 and extension 19 are formed integrally in the present embodiment, wherein the extension 19 and the edge portion by means of a deformation process, for example by a deep drawing process, is formed from the carrier element 12. The lower end of the crankshaft 1 is pressed into the through opening 13 here in the present embodiment, the rotationally fixed connection of support member 12 and produce crankshaft 1.

[0039] Around the mounting locations of the crankshaft 1 in the bearing bush 17 and the piston-cylinder unit in an operating state of the refrigerant compressor 5 to lubricate and lubricant from a bottom region of the compressor housing 7 with operating state 6 to supply lubricant sump formed, faces the crankshaft 1 on which the piston-cylinder unit 5 opposite end, i.e. at the lower end, a longitudinal axis extending inclined 2, in other words a substantially axially extending, eccentric bore (not shown) on, which radially disposed eccentrically to the longitudinal axis 2. Lubricant which passes into the eccentric bore due to the centrifugal force during rotation of the crankshaft 1 is to the wall of the eccentric bore and a result of the increased pressure in the direction of the pressed piston-cylinder unit 5 promoted. For example the eccentric bore can as a blind hole and to which the piston-cylinder unit 5 carried out via a radial bore 20 having an end facing the circumferential surface of the crankshaft 1 for delivering the lubricant groove formed 22 connected.

[0040] In alternative execution variants can also be arranged so as to extend parallel to the longitudinal axis the eccentric bore 2 or in place of the eccentric bore may be provided extending axial bore coaxially to the longitudinal axis 2.

[0041] Lubricant from the lubricant sump in the eccentric bore now to the crankshaft 1 without a free end of the crankshaft 1 to the lubricant sump must immersion, a sleeve-shaped lubricant receiving 8 is provided, which on the support element 12 fixed against rotation on the crankshaft 1 and thus is attached. The lower end of the crankshaft 1 is pressed into the through opening 13 of the extension 19 of the carrier element 12 here. In the present embodiment are the sleeve-shaped lubricant receiving 8 and the carrier element 12 formed in two parts, wherein a fixing portion of the support member 12 contacts the lubricant receiving the extension 19 9 8.

[0042] As shown in Figure 2 seen well, the attachment section has a circularly cylindrical internal cross-section on 9, wherein an inner surface of the mounting portion of the sleeve-shaped extension 19 of the support member 12 rests on an outer surface 9. In other words the fixing portion 9 of the sleeve 8 is slid on the lubricant receiving extension 19. A rotationally fixed connection between 8 and 12 produce lubricant receiving support member, the attachment section 9 is the extension 19 of the support member 12 usually pressed or shrunk, so that a non-positive or frictional connection is made.

[0043] On the one hand and on the other hand connection of the support member 12 to the crankshaft 1 of the mounting portion to the extension 19 to improve connection 9 and the surface pressure between support member 12 and between the fastening portion and fastening portion 9 or 9 to increase crankshaft 1, is a portion of the mounting portion 11 formed as an annular support member 9. It is in the present embodiment the carrier element 12 facing the end of the mounting portion, wherein the annular support member extends in the axial direction of the fixing section 11 above about 80% 9 seen. The annular support member 11 has a very high wall thickness on the rest of the lubricant receiving 8, 9 in the region of the support member so that the mounting portion 11 has a high rigidity.

[0044] Is a safe stop in the extension 19 of the mounting portion 9 ensure. In alternative execution variants can the annular support member 11 from the lubricant receiving 8 represent a separate part, which is pressed or shrunk onto the outside on the mounting portion 9. In other words the support element contacts an outer peripheral surface of the mounting portion 11 and exerts radially inwardly in the direction of the longitudinal axis 9 2 directed force on the mounting portion 9 from. This force by increasing the surface pressure and the quality of the connection between the inner surface of the through hole 13 - or frictional force and the crankshaft or between the inner surface of the mounting portion 9 and the outer surface of the extension 19.

[0046] The support member contacts a bottom surface of the carrier element 12 and about 80% in 11 overlaps the extension 19.

[0047] It is understood this of itself, that the annular support member 11 for fastening the lubricant receiving the extension 19 8 is beneficial, but not strictly necessary. Alternatively or additionally the uppermost portion of the supporting element 11 can also have a collar portion 8 lubricant receiving, at least in sections in the extending radially outwardly.

[0048] Via a lubricant inlet opening into a receiving portion 10 of the lubricant receiving a lubricant passage 8. Since the lubricant receiving 8 a rotationally symmetrical shape relative to the longitudinal axis 2 and is arranged coaxially to the longitudinal axis 2, is formed by the rotation of a parabola or a paraboloidal shaped 8 lubricant receiving lubricant in the lubricant receiving lubricant from column 8, at the lower end of the crankshaft 1 into the eccentric bore in the direction of the first radial bore 20 further transfer and there is promoted.

[0049] With increasing distance between a level of the lubricant sump and radial bore 20, also referred to as delivery head, the delivery rate of the lubricant conveyor system decreases. By fixing the sleeve-shaped extension 19 of the support element on the lubricant receiving 8 is a particularly space-saving connection of the lubricant receiving 8 to the crankshaft reaches 1, whereby the transfer height may be reduced and thus the delivery rate, therefore the lubricant flow rate per minute, can be increased. That may explain the increase in capacity, due to the smaller transfer height that the wall thickness of the lubricant in the region of the radial bore 20 is larger and thus more parabola lubricant in the helical groove 22 passes.

[0050] In a not shown alternative embodiment variant of the invention is provided, and support member 12 are integrally formed and said that lubricant receiving 8 8 rotation on the carrier element 12 or in lubricant receiving to the crankshaft 1 is attached. For example can be achieved by the integrity, together with lubricant receiving 8 that the support element 12 is prepared from a plate-shaped raw cut a deep-drawing process. In this embodiment the lower end of the crankshaft 1 is an upper portion of the lubricant receiving 8 is pressed on the lower end of the crankshaft or the lubricant receiving 8 1 shrunk.

[0051] Figure 3 shows a second embodiment of the invention, which differs from the first embodiment in individual aspects, why only on the differences in the sequence is received.

[0052] 19 Of the support member 12 while the sleeve-shaped extension in said first configuration the side facing away from the piston-cylinder unit 5 variant extends, extends the extension 19 in the present embodiment in the direction of the piston-cylinder unit 5 (1 figfig. comparisons). In other words the extension 19 in the present embodiment is upwardly bulged. The extension 19 integrally formed with the support member 12 by means of a bending and in turn can be prepared - or deep-drawing process. In the first embodiment is the lower end of the crankshaft 1 by the sleeve-shaped extension of the carrier element 12 formed through hole 19 in the 13 arranged. In the second embodiment of the lower end of the crankshaft 1 a central recess 29 on end face, in which the sleeve-shaped extension 29 recess 19 is held in a rotationally fixed manner. For example the extension 19 can be pressed into the recess 29. The lubricant receiving 8 here is rotationally fixedly held in the through opening 13. This can also for example be accomplished by pressing the lubricant receiving 8 into the through opening 13.

[0053] In the lubricant receiving 8 can further be arranged a lubricant carrier 16, forming the lubricant and the capacity of the parabola which supports increased oil feeding. In each of the above-described embodiments is therefore a lubricant in the lubricant receiving driver 16 8 arranged, which at least one or more helical surfaces, which the lubricant outwardly towards the inner wall of the lubricant receiving 8 or urging of the lubricant in the axial direction for urging upwardly toward the eccentric bore of the crankshaft 1 are formed. It is also conceivable, that the one or more surfaces of the lubricant driver 16 are planar.

Crankshaft

Longitudinal axis of the crankshaft 1

The stator

A rotor

Piston-cylinder unit compressor housing

Bottom portion of the compressor housing 6 sleeve-shaped lubricant receiving fastening portion of the receiving portion of the support member of the support member 8 8 lubricant receiving lubricant receiving annular permanent magnet rotor 4 through opening

Short ring lubricant driver

Bearing bush

Support housing

sleeve-shaped extension of the carrier element 12 radial bore

Spring element

Helical groove

Connecting rod

Cylinder housing

Piston

Crank pin

Cylinder head arrangement suction sound damper

Recess of the crankshaft 1