A piston pump includes: a tilting mechanism configured to bias a swash plate in accordance with a control pressure; a support spring configured to support the swash plate; and a regulator configured to control a control pressure guided to the tilting mechanism in accordance with a self-pressure of the piston pump. The regulator has an outer spring and an inner spring configured to be extended and compressed by following tilting of the swash plate; and a control spool configured to be moved in accordance with a biasing force from the outer spring and the inner spring, the control spool being configured to regulate the control pressure, and the outer spring and the inner spring and the support spring are provided adjacent to each other and in parallel with respect to the swash plate.

A piston pump includes: a tilting mechanism configured to bias a swash plate in accordance with a control pressure; a support spring configured to support the swash plate; and a regulator configured to control a control pressure guided to the tilting mechanism in accordance with a self-pressure of the piston pump. The regulator has an outer spring and an inner spring configured to be extended and compressed by following tilting of the swash plate; and a control spool configured to be moved in accordance with a biasing force from the outer spring and the inner spring, the control spool being configured to regulate the control pressure, and the outer spring and the inner spring and the support spring are provided adjacent to each other and in parallel with respect to the swash plate.

A piston pump includes: a tilting mechanism configured to bias a swash plate in accordance with a control pressure; a support spring configured to support the swash plate; and a regulator configured to control a control pressure guided to the tilting mechanism in accordance with a self-pressure of the piston pump. The regulator has an outer spring and an inner spring configured to be extended and compressed by following tilting of the swash plate; and a control spool configured to be moved in accordance with a biasing force from the outer spring and the inner spring, the control spool being configured to regulate the control pressure, and the outer spring and the inner spring and the support spring are provided adjacent to each other and in parallel with respect to the swash plate.

A piston pump includes: a tilting mechanism configured to bias a swash plate in accordance with a control pressure; a support spring configured to support the swash plate; and a regulator configured to control a control pressure guided to the tilting mechanism in accordance with a self-pressure of the piston pump. The regulator has an outer spring and an inner spring configured to be extended and compressed by following tilting of the swash plate; and a control spool configured to be moved in accordance with a biasing force from the outer spring and the inner spring, the control spool being configured to regulate the control pressure, and the outer spring and the inner spring and the support spring are provided adjacent to each other and in parallel with respect to the swash plate.

It includes a plurality of cylinders formed on the cylinder block; a piston slidably inserted into the cylinder; a case accommodating the cylinder block; and a valve plate formed by a core member and a resin layer coating the core member, the valve plate being interposed between the cylinder block and an end cover of the case. The valve plate has a first land portion formed by the resin layer, the first land portion being in sliding contact with the cylinder block; and an outer-side non-contact portion provided closer to an outer side in a radial direction than the first land portion, the outer-side non-contact portion being separated away from the cylinder block. At least a part of the outer-side non-contact portion is an exposed portion where the core member is exposed.

A hydrostatic positive displacement machine has a cylinder drum (4) located in a housing (9) and rotatable around an axis of rotation (2). During rotation of the cylinder drum (4), a piston bore (5) is placed in alternating communication with an inlet side (E) and an outlet side (A). The inlet side (E) and outlet side (A) comprise connections (21; 22) to a control plate (12). A reversing device (30) is located in a reversing area (25; 26) between the connections (21, 22) on the control plate (12). The reversing device (30) damps the pressure adjustment between a displacement chamber (V) and the pressure present in the connection (21; 22). The reversing device (30) includes at least two flow connections which are actuated simultaneously by the displacement chamber (V) as it moves along the reversing area (25; 26).

An axial variable displacement piston pump includes a drive shaft disposed on an axis, a piston barrel comprising a plurality of pistons disposed about the drive shaft, and a swash plate disposed about the drive shaft. Each of the piston barrel and the swash plate are rotationally coupled to the drive shaft such that the drive shaft is configured to simultaneously drive rotation of each of the piston barrel and the swash plate.