The present disclosure relates to an adjusting device for adjusting the swash plate of an axial piston machine comprising an adjusting piston, which is connected to the swash plate of the axial piston machine via an adjusting lever, and a regulator for adjusting the adjusting pressure acting on the adjusting piston in dependence on a control force acting on a control piston of the regulator, wherein the adjusting piston is connected to the control piston via a feedback spring.

An axial piston machine includes a housing, an actuating piston, and a closing screw. The housing includes a cylinder bore, a recess, and a fluid channel. An end of the bore open to an outside of the housing has an internal thread. The recess is located in a region of the internal thread, and is deeper than a thread depth of the internal thread so that a floor region of the recess is free from thread turns. The piston is linearly moveable in the cylinder bore, and is configured to adjust a displacement volume of the machine. The screw is screwed into the internal thread so as to form a closed chamber between the piston and the screw. The fluid channel opens into the floor region of the recess, and is fluidically connected to the cylinder chamber.

A hydrostatic axial piston machine includes a housing, a connection plate closing the housing, working connections formed on the connection plate, a drive shaft, a swashplate, a cylinder drum coupled to the shaft in the direction of rotation, bores formed in the drum and each including a piston, a control plate against which the drum bears, a retraction plate for removing a piston from the bores, and a retraction ball arranged in front of the first end face of the drum which surrounds a drum neck of the drum and the shaft and by which the retraction plate is loaded in the direction of the swashplate. A pressure chamber is defined by seals between the retraction ball, the drum, and the shaft, and is configured to be acted upon by a pressure above a housing pressure. The retraction ball is sealed against the drum neck and against the shaft.

The invention relates to a device (10) for controlling the displacement of a machine (20) with axial pistons comprising a case (23) that houses a control unit comprising a displacement control spool (110) adapted to be switched between two positions by a control pressure (Ps) according to an axis of sliding (): a working position wherein the control spool (110) provides a connection between at least one inlet (103, 104) that receives a supply pressure and an outlet (105, 106) connected to a cylinder for adjusting the inclination of said machine (31a, 31b), and an idle position wherein the control spool (110) interrupts the connection between said inlet (102, 104) and said outlet (101, 103), and comprising means for switching adapted to vary the position of the adjusting cylinder (31a, 31b), a spring (140), characterised in that: said means of communication comprise a second switching spool (130), coaxial to the control spool (110), a switching pressure (Pm) exerts an axial force on the second spool (130) in the direction of the control spool (110), the spring (140) exerts an axial force on the two spools (110, 130), which tends to move them apart from each other, control pressure (Ps) exerts an axial force on the control spool (110) in the direction of the second tool (130).

A cylinder block includes: a plurality of cylinder bores including respective openings formed on a piston insertion end surface of the cylinder block, pistons being inserted in the respective cylinder bores and being configured to reciprocate and slide in the respective cylinder bores when the cylinder block rotates; and a cooling portion, wherein the cooling portion includes a plurality of cooling holes each formed between the adjacent cylinder bores and extending from the piston insertion end surface in an axial direction of the cylinder block.

A hydraulic unit includes a driving mechanism whose displacement volume is adjustable to two operational states by means of a position-able adjustment element. The adjustment element can be positioned by a servo piston of a servo unit into a first, initial position and a second, operative position. A first front face and a second front face of the servo piston, which are opposing each other, can be pressurized individually with pressurized hydraulic fluid in order to position the servo piston at either end position of a servo cylinder of the servo unit. The servo piston is of a stepped design thereby forming a ring-shaped damping surface opposing the first front face. In the servo cylinder a ring-shaped shoulder surface is formed opposing the damping surface such that a damping volume is formed in the servo cylinder by the damping surface, the shoulder surface and the servo cylinder.

A hydraulic transaxle includes a transaxle casing including an upper transaxle housing and a lower casing, hydrostatic transmission (HST), and an axle. The HST has a hydraulic pump and a hydraulic motor that are fluidly connected to each other. The hydraulic motor has a motor shaft that is drivingly connected to the axle through a reduction gear train that is disposed between the hydraulic pump and the axle. Reduction gear train has a gear shaft supported by the upper transaxle housing via a ball bearing. At least a part of the upper transaxle housing is formed by a gear top cover made of metal and covering the reduction gear train. Ball bearing is supported by the upper transaxle housing and the gear top cover.

A hydrostatic piston engine comprises a housing with a cylinder drum with cylinder bores mounted rotatably therein. Each of the cylinder bores receives a working piston in a longitudinally displaceable manner, via which a hydrostatic working chamber is delimited by the cylinder bore. The hydrostatic working chamber has an opening on an outer surface of the cylinder drum by which, when the cylinder drum rotates, outlets of a high-pressure chamber and of a low-pressure chamber of the piston engine and a reversing surface arranged between the two outlets in the rotational direction can be passed over in alternating fashion. At least one pressurizing medium channel is provided which, on one hand, opens out in the reversing surface and, on the other, into a pressurizing medium trough of the piston engine.

The present disclosure relates to an adjusting device for adjusting the swash plate of an axial piston machine comprising an adjusting piston, which is connected to the swash plate of the axial piston machine via an adjusting lever, and a regulator for adjusting the adjusting pressure acting on the adjusting piston in dependence on a control force acting on a control piston of the regulator, wherein the adjusting piston is connected to the control piston via a feedback spring. In accordance with the present disclosure the feedback spring is at least partly received in a pot-shaped recess of the control piston.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.