A modular hydraulic device comprising: a housing having a receptacle having a first open end, a second end and a first port, the first port for facilitating an ingress and an egress of hydraulic fluid with respect to the housing; a sleeve configured to be received in the first open end and abut the second end; and an end cap for closing the first open end once the sleeve is inserted in the receptacle; the sleeve having: a body having a fourth lan (L4) positioned in the body for aligning with first port; a main cylinder for holding a main piston for reciprocation about a reciprocation axis; and a first bore portion fluidly coupled to the first lan, the first bore portion for receiving the ingress of the hydraulic fluid and for outputting the egress of the hydraulic fluid; wherein once assembled the main piston is coupled to a cam for facilitating said reciprocation.

The present disclosure discloses a swashplate-type axial plunger pump with multi-channel oil feed and full-flow self-cooling and double-end-face flow distribution. The cooling oil suctioned by the plunger pump firstly cools the friction pair of the cylinder block and the plunger; then, one part of the cooling oil passes through a gap between the pump case and the cylinder block and enters the control chamber by passing by the friction pair of the oil distribution plate and the cylinder block to cool the friction pair of the oil distribution plate and the cylinder block; and the other part of the cooling oil passes through a gap between the pump case and the cylinder block and enters the control chamber by passing by the friction pair of the slipper and the swashplate to cool the friction pair of the slipper and the swashplate.

The present disclosure discloses a swashplate-type axial plunger pump with multi-channel oil feed and full-flow self-cooling and double-end-face flow distribution. The cooling oil suctioned by the plunger pump firstly cools the friction pair of the cylinder block and the plunger; then, one part of the cooling oil passes through a gap between the pump case and the cylinder block and enters the control chamber by passing by the friction pair of the oil distribution plate and the cylinder block to cool the friction pair of the oil distribution plate and the cylinder block; and the other part of the cooling oil passes through a gap between the pump case and the cylinder block and enters the control chamber by passing by the friction pair of the slipper and the swashplate to cool the friction pair of the slipper and the swashplate.

A piston pump includes a rotor member with a bore therein. The bore is defined by an inner surface. The piston pump also includes a piston supported for reciprocating movement in an axial direction within the bore to change a volume of a pump chamber that is cooperatively defined by the piston and the rotor member. The piston has an outer surface that faces the inner surface with a leakage interface defined therebetween. The leakage interface is configured to receive a passive leakage flow of a fluid from the pump chamber through the leakage interface to provide cooling. Moreover, the outer surface includes a relief feature that is recessed into the outer surface to define, with the inner surface, a cooling pocket of the leakage interface. The cooling pocket moves in the axial direction relative to the inner surface with the reciprocating movement of the piston.

A method of closing an externally open segment of a fluid end of a reciprocating pump with a closure assembly includes inserting a non-circular closure element into a segment of a fluid end casing in a first direction while the non-circular closure element is disposed in a first orientation. The non-circular closure element is rotated to a second orientation that is angularly offset from the first orientation with respect to at least one axis of rotation. The non-circular closure element is further moved within the segment of the fluid end casing in a second direction that is opposite the first direction to cause the non-circular closure element to seat within the segment.

A method of closing an externally open segment of a fluid end of a reciprocating pump with a closure assembly includes inserting a non-circular closure element into a segment of a fluid end casing in a first direction while the non-circular closure element is disposed in a first orientation. The non-circular closure element is rotated to a second orientation that is angularly offset from the first orientation with respect to at least one axis of rotation. The non-circular closure element is further moved within the segment of the fluid end casing in a second direction that is opposite the first direction to cause the non-circular closure element to seat within the segment.

A closure element for a fluid end of a reciprocating pump is installable within a segment of a casing of the fluid end to substantially close the segment. The closure element includes a main body that extends from an interior surface to an exterior surface, and at least a portion of the main body has a non-circular cross-sectional shape. A fluid end for the closure element may include a plurality of segments and at least a portion of at least one segment of the plurality of segments may have a non-circular cross-sectional shape configured to receive and secure a closure element with a non-circular cross-sectional shape.

A closure element for a fluid end of a reciprocating pump is installable within a segment of a casing of the fluid end to substantially close the segment. The closure element includes a main body that extends from an interior surface to an exterior surface, and at least a portion of the main body has a non-circular cross-sectional shape. A fluid end for the closure element may include a plurality of segments and at least a portion of at least one segment of the plurality of segments may have a non-circular cross-sectional shape configured to receive and secure a closure element with a non-circular cross-sectional shape.

A fluid end having as fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits, each kit comprising a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A fluid end having as fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits, each kit comprising a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.