Drill pump hydraulic end

The invention provides a fluid-end of a drilling pump, which belongs to the petroleum drilling machinery equipment field and comprises a drilling liquid cavity, a diaphragm device and a lubricating liquid cavity. The diaphragm device is arranged between the drilling liquid cavity and the lubricating liquid cavity, and a diaphragm divides the fluid-end of the drilling pump into two separate parts which are the drilling liquid cavity and the lubricating liquid cavity, the drilling liquid has no direct contact with a cylinder sleeve and a piston of the lubricating liquid cavity. The curve length of the outer diaphragm surface of the diaphragm device is equal to the curve length of the inner surface in the shell. The shape of the diaphragm is spherical or ellipsoid after full expansion. The advantages of the invention are that the working environment of the piston and the cylinder are improved, the abrasion between the piston and the cylinder sleeve are remarkably reduced and thus the service ...