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 hydraulic piston unit including a rotational group for driving or being driven by a driving shaft, and having a tiltable displacement element for adjusting the displacement volume of the rotational group between a minimum or a maximum displacement, wherein, on t valve segment between a kidney-shaped inlet port and a kidney-shaped outlet port at respective dead end positions of reciprocally moveable working pistons first and second control ports are located in fluid connection with cylinder bores in the cylinder block, for controlling the position of the displacement element. The hydraulic piston unit further includes a control valve with a shiftable control valve spool fluidly connected via a high pressure port to a high pressure side of the hydraulic piston unit. The control valve spool is configured to conduct hydraulic fluid from the high pressure side to one of the first or the second control port.

A hydraulic piston unit including a rotational group for driving or being driven by a driving shaft, and having a tiltable displacement element for adjusting the displacement volume of the rotational group between a minimum or a maximum displacement, wherein, on t valve segment between a kidney-shaped inlet port and a kidney-shaped outlet port at respective dead end positions of reciprocally moveable working pistons first and second control ports are located in fluid connection with cylinder bores in the cylinder block, for controlling the position of the displacement element. The hydraulic piston unit further includes a control valve with a shiftable control valve spool fluidly connected via a high pressure port to a high pressure side of the hydraulic piston unit. The control valve spool is configured to conduct hydraulic fluid from the high pressure side to one of the first or the second control port.

A hydraulic machine has a first assembly and a second assembly movable in rotation relative to each other along an axis of rotation. The hydraulic machine has a crankcase defining an internal volume, in which an interface between the fixed assembly and the movable assembly has a housing provided with a first sealing element ensuring the sealing of the internal volume relative to the external environment. A second sealing element is positioned between the internal volume and the housing. The second sealing element is adapted to allow a passage of fluid from the internal volume to the housing when the pressure deviation between the internal volume and the housing is less than or equal to a threshold value, and to isolate the housing from the internal volume when the pressure deviation is greater than the threshold value.

In the hydraulic pump according to the present invention, a straight path among the paths, through which the fluid flows within the hydraulic pump, and a connection point on the straight path are formed to have curvatures, so that it is possible to prevent stress from being concentrated to the connection point, thereby improving durability, and it is possible to manufacture the hydraulic pump by forming a casting shape with a curvature in advance, thereby decreasing additional machining and decreasing costs of a product.

A fluid end having its 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 that each comprise 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 its 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 that each comprise 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.

An axial piston pump has a rotor rotatable around an axis relative to a swashplate; one or more pistons movable within one or more respective sleeves; a fluid inlet port for the inflow of low pressure fluid, and a fluid outlet port for the outflow of high pressure fluid; and a floating element axially positioned between, on the one side, the inlet and outlet ports and, on the other side, a sealing surface of the rotor. Surfaces of the floating element defining an inlet chamber and the outlet chamber are configured such that, in use, the low pressure fluid and the high pressure fluid act on the defining surfaces to produce a net axial force which the axially slidable floating element applies to the rotor to seal the floating element to the sealing surface of the rotor.