A fluid end assembly of a hydraulic fluid pump includes a housing having a first housing bore and a second housing bore offset axially from the first housing bore. A plate is fastened to the housing. The plate has a first plate bore axially aligned with the first housing bore and a second plate bore axially aligned with the second housing bore. A first removable valve cover closes the first housing bore and a second removable valve cover closes the second housing bore. A first retainer engages the first plate bore and abuts the first removable valve cover and a second retainer engages the second plate bore and abuts the second removable valve cover.

A hydraulic machine includes radial cylinders including, oscillating radial cylinders arranged in a crown or star of cylinder-piston units, the pistons of the groups are made slidable on a crankshaft or with a cam, or on interposed members concentric to it, and realizing the reciprocating motion in the oscillating cylinders. The oscillating cylinders are placed in contact with a surface of distribution concentric or corresponding to the surface of oscillation of the respective cylinder on which a distributor body is placed separate from the machine body and housed in a seat in the body, or part fixed to the body, of the hydraulic machine, and each distributor body is mobile in its seat under the action of the pressure of liquid in connection on the back surface of the distributor body against the surface of distribution of the oscillating radial cylinder subject to the distribution.

A positive displacement pump is provided. The pump comprises at least one piston operable to be powered by a power source and to pressurize a fluid. The at least one piston comprises an at least partially hollow piston wherein a flow of fluid is induced into and through the piston and a surrounding piston chamber. The piston preferably comprises a direct-mounted outlet valve for controlling a flow of fluid into and out of the piston.

The pump can have a support having a guide extending around an axis, a radial position of the guide relative the axis varying around the axis, and a first oil passage formed in the support; a rotary assembly mounted to the support via support bearings, and rotatable around the axis, the rotary assembly having a second oil passage and a cylinder, the cylinder extending radially relative the axis, an inlet port fluidly connecting the first oil passage to the cylinder, and an outlet port fluidly connecting the cylinder to the second oil passage, and a piston slidingly mounted in the cylinder, a radially-outer end of the piston further slidingly engaged with the guide.

The pump can have a support having a guide extending around an axis, a radial position of the guide relative the axis varying around the axis, and a first oil passage formed in the support; a rotary assembly mounted to the support via support bearings, and rotatable around the axis, the rotary assembly having a second oil passage and a cylinder, the cylinder extending radially relative the axis, an inlet port fluidly connecting the first oil passage to the cylinder, and an outlet port fluidly connecting the cylinder to the second oil passage, and a piston slidingly mounted in the cylinder, a radially-outer end of the piston further slidingly engaged with the guide.

The disclosure describes a fluid plate assembly that includes a plurality of fluid plates and one or more seals between the plurality of fluid plates. The plurality of fluid plates are coupled together to form a fluid passage. At least one fluid plate of the plurality of fluid plates includes a plurality of holes and one or more fluid channels. The plurality of holes are configured to spray pressurized fluid on at least a portion of one or more components of a rotary machine. The one or more fluid channels that form the fluid passage are configured to direct the pressurized fluid to the plurality of holes.

The disclosure describes a fluid plate assembly that includes a plurality of fluid plates and one or more seals between the plurality of fluid plates. The plurality of fluid plates are coupled together to form a fluid passage. At least one fluid plate of the plurality of fluid plates includes a plurality of holes and one or more fluid channels. The plurality of holes are configured to spray pressurized fluid on at least a portion of one or more components of a rotary machine. The one or more fluid channels that form the fluid passage are configured to direct the pressurized fluid to the plurality of holes.

A pump fluid end having a reciprocating element a discharge valve assembly, a suction valve assembly, and a suction valve stop. The reciprocating element is disposed at least partially within a reciprocating element bore of the pump fluid end. The suction valve assembly is coupled with a front end of the reciprocating element. The suction valve stop is positioned within the reciprocating element bore such that the suction valve stop contacts and applies a closing force to the suction valve assembly when the suction valve assembly is stuck open at the end of a discharge stroke of the reciprocating element.

A control plate (18) of a hydraulic machine is described, the control plate (18) includes a body (21), an arrangement of openings (22, 23), and a contact face (24). In order to operate a hydraulic machine with a low noise level the body (21) is made of a plastic material. The control plate may be used as port plate or as valve plate.