An actuating cylinder for an adjustment apparatus of a pivot angle of a hydrostatic axial piston machine has a hydraulic stop which connects an actuating pressure chamber of the actuating cylinder to an interior of the housing of the axial piston machine if the actuating piston is maximally extended. To this end, a channel is provided on the actuating piston side, while a control edge is provided on the housing side. The control edge is formed at the interface of a stop bore with the actuating cylinder bore. The stop bore may also be a leakage bore of the axial piston machine.

An actuating cylinder for an adjustment apparatus of a pivot angle of a hydrostatic axial piston machine has a hydraulic stop which connects an actuating pressure chamber of the actuating cylinder to an interior of the housing of the axial piston machine if the actuating piston is maximally extended. To this end, a channel is provided on the actuating piston side, while a control edge is provided on the housing side. The control edge is formed at the interface of a stop bore with the actuating cylinder bore. The stop bore may also be a leakage bore of the axial piston machine.

An axial piston pump, particularly for hydraulic systems, includes a cylinder drum (1) rotationally driven about an axis (15) in a pump housing (7). Piston cylinder units are arranged in the drum in a circle at an offset. Pistons (21) are at least indirectly supported on a swashplate (3) by their actuation end (31) accessible outside the cylinder drum (1). Between the swept volumes (19) of the piston cylinder units and a stationary fluid inlet and stationary fluid outlet of the pump housing (7), a control device (23) is arranged that has fluid channels (25, 26) for the targeted transfer of fluid from the fluid inlet into the swept volumes (19) and from the swept volumes (19) to the fluid outlet. At least one pressure compensation channel (28, 30) is provided in the control device (23), between the fluid channels (25, 26), to build or release fluid pressure in the swept volumes (19) in a targeted manner.

In a drive device using a hydraulic pump controlled by a rotatable swash plate, the swash plate includes a pocket and a trunnion engaged to the pocket and rotatable about an axis of rotation offset from the swash plate axis of rotation. An interface is formed on a first end of the trunnion, and a first arcuate side of the interface engages a flat portion of the first side of the pocket as the trunnion is rotated in a first direction, and a second arcuate side of the interface engages a flat portion of the second side of the pocket as the trunnion is rotated in the opposite direction. The swash plate may also include at least one protrusion on a top surface extending in a direction perpendicular to swash plate axis of rotation to engage the housing and limit axial movement of the swash plate.

The present invention addresses the problem of providing a swash-plate hydraulic motor or a swash-plate hydraulic pump having a structure in which the swash plate can be stably held without mounting a shoe to the swash plate-side end of a tilt control piston. An example of the embodiment of the present invention is a swash-plate hydraulic motor (1). A spherical section (8b) is integrally formed on the swash plate-side end surface of a tilt piston (8), and a groove (10) into which the spherical section (8b) is fitted in a slidable manner is formed in the support surface (7b) (second support surface (7b2)) of the swash plate (7). The groove (10) is a part of the second support surface (7b2) and has a shape having a predetermined width and having a longitudinal direction which is oriented perpendicularly to the direction which connects two pivots (11).

A hydraulic pump, in particular an adjustable axial piston pump, has at least one piston (22) movable in a reciprocating manner in a longitudinal direction within a pump housing during operation of the hydraulic pump. The piston (22) has a link head (24), a piston top (54) opposite the link head (24), and at least one hollow chamber (60) surrounded at least partially by a piston housing (62) that substantially or completely terminates each hollow chamber (60) towards the outside. A piston (22) for such hydraulic pump is also provided.

A method for coating a pump component (23, 31), in particular, a part of an axial piston pump (7), having the steps of providing a blank of the component (23, 31), providing at least one recess in the blank, filling a powdery coating material into the associated recess, melting the coating material under a protective gas atmosphere and material-removing processing of the blank to form at least one sliding and/or bearing surface (6) from the coating.

An axial piston pump has a swash-plate construction, in particular for hydraulic systems. A cylinder drum (3) can be rotationally driven about a rotational axis (7) in a pump housing (1). Pistons (9) are axially displaceable and support at their actuation ends a swash plate (15). The swash plate can be pivoted by an adjusting device (21) to the desired angles of inclination relative to the rotational axis (7) for adjusting the stroke of the pistons (9) and the fluid pressure generated. The adjusting device has an adjusting piston (35) in a hydraulically actuated adjusting cylinder (31). Their movement can be transmitted to the swash plate (15) by a driven connection having a pivot joint (37, 39; 29, 43). The pivot joint is formed by a ball joint (37, 39) arranged between the piston (35) and the piston rod (41) of the adjusting cylinder (31).