A swash-plate type piston pump includes a cylinder block configured to be rotated with rotation of a driving shaft, a plurality of pistons accommodated in a plurality of cylinders provided in the cylinder block, a swash plate configured to reciprocate the piston so that a volume chamber of the cylinder is expanded/contracted with the rotation of the cylinder block, an biasing mechanism configured to bias the swash plate in a direction where a tilting angle is made larger, a control pin configured to drive the swash plate in a direction where the tilting angle is made smaller in accordance with a rise in a load pressure of a pressure chamber, and a discharge channel configured to discharge the load pressure of the pressure chamber.

A nitriding layer (13) is formed on the front surface side of a base material of a cylinder block (7) including an opening side end surface (7B) and each cylinder hole (12). Then, a piston sliding surface (12A) of each cylinder hole (12) is formed as a compound layer-removed hole (17) by removing a compound layer (16) that is located on the front surface side of the nitriding layer (13) by using polishing means such as, for example, honing and so forth. Further, a compound layer-removed surface (18) is formed on a part (A) where a compound layer-removed hole (17) and a cylinder inlet side tapered surface (12B) of each cylinder hole (12) intersect by using the polishing means such as, for example, the honing and so forth. This compound layer-removed surface (18) is formed as a tapered-state inclined surface of an angle α.

A swash-plate type piston pump motor includes: a rotary shaft; a cylinder block that rotates together with the rotary shaft; a plurality of pistons (5) each of which is inserted so as to be reciprocable in each of a plurality of cylinders formed in the cylinder block; a plurality of piston shoes (6) attached so as to be swingable to an end portion (501) of each piston; a swash plate (7) inclined with respect to an axis of the rotary shaft and having a sliding surface (41) being in contact with a plurality of piston shoes; and a shoe retainer (8) configured to press the piston shoe against the sliding surface. Each piston shoe includes a shoe body (71) being in contact with a sliding surface, and an elastic body (79) provided between the shoe body and the shoe retainer.

A swash-plate type piston pump motor includes: a rotary shaft; a cylinder block that rotates together with the rotary shaft; a plurality of pistons (5) each of which is inserted so as to be reciprocable in each of a plurality of cylinders formed in the cylinder block; a plurality of piston shoes (6) attached so as to be swingable to an end portion (501) of each piston; a swash plate (7) inclined with respect to an axis of the rotary shaft and having a sliding surface (41) being in contact with a plurality of piston shoes; and a shoe retainer (8) configured to press the piston shoe against the sliding surface. Each piston shoe includes a shoe body (71) being in contact with a sliding surface, and an elastic body (79) provided between the shoe body and the shoe retainer.

A rotary type valve plate compressor may include a shaft, a housing through which the shaft passes, a plurality of cylinders mounted in the housing, a piston received in the cylinder and to be moved forward and rearward in response to rotational operation of a swash plate, and a rotary type valve plate to receive a rotational force of the shaft and to open and close a refrigerant passage hole through which refrigerant passes, based on a phase of the piston.

A rotary type valve plate compressor may include a shaft, a housing through which the shaft passes, a plurality of cylinders mounted in the housing, a piston received in the cylinder and to be moved forward and rearward in response to rotational operation of a swash plate, and a rotary type valve plate to receive a rotational force of the shaft and to open and close a refrigerant passage hole through which refrigerant passes, based on a phase of the piston.

A hydrostatic axial piston machine includes a pressing pressure chamber for the cylinder drum which is supplied with pressing pressure from a circular-arc-like elongate hole of a distributor plate or from a plurality of connection channels of the cylinder drum. The pressing pressure chamber is delimited radially outwardly by the cylinder drum and radially inwardly by the drive shaft. The pressing pressure chamber is delimited axially at both sides by seals which are both arranged between the radially inner rotating drive shaft and a radially outer stationary component. The radially outer component may be the cylinder drum or, in the case of the distributor-plate-side seal, also a gap seal between the drive shaft and a bearing bush of the distributor plate. Both seals are arranged at the distributor plate side with respect to a tooth arrangement or a retraction ball.

A hydrostatic axial piston machine includes a pressing pressure chamber for the cylinder drum which is supplied with pressing pressure from a circular-arc-like elongate hole of a distributor plate or from a plurality of connection channels of the cylinder drum. The pressing pressure chamber is delimited radially outwardly by the cylinder drum and radially inwardly by the drive shaft. The pressing pressure chamber is delimited axially at both sides by seals which are both arranged between the radially inner rotating drive shaft and a radially outer stationary component. The radially outer component may be the cylinder drum or, in the case of the distributor-plate-side seal, also a gap seal between the drive shaft and a bearing bush of the distributor plate. Both seals are arranged at the distributor plate side with respect to a tooth arrangement or a retraction ball.

A device, system, and process for turning hydraulic pressure into rotational force and for turning rotational motion into hydraulic pressure. An example of the device/system for performing the process comprises actuators, rotationally positioned between two thrust plates that are fixed in a housing at an angle to a rotational axis and in parallel to each other.

A device, system, and process for turning hydraulic pressure into rotational force and for turning rotational motion into hydraulic pressure. An example of the device/system for performing the process comprises actuators, rotationally positioned between two thrust plates that are fixed in a housing at an angle to a rotational axis and in parallel to each other.