A hydraulic machine is described comprising a first part (1, 4) and a second part (7, 8), wherein the first part (1, 4) and the second part (7, 8) are movable relatively to each other in abutting relation, the first part (1, 4) comprises a pressure chamber (2) having a pressure chamber opening (6) in a contact face (5) contacting a sealing face (9) of the second part (7, 8), the second part (7, 8) comprises a low pressure area (10) connected to a low pressure opening (11) in the sealing face (9) and a high pressure area (12) connected to a high pressure opening (13) in the sealing face (9), wherein during a movement of the first part (1, 4) with respect to the second part (7, 8) in a moving direction (14) the pressure chamber opening (6) comes alternatingly in overlap with the low pressure opening (11) and the high pressure opening (13). Such a machine should be flexible in operation with low risk of damages caused by cavitation. To this end a throttling channel (15) in the second part (7, 8) connects the low pressure area (10) with an area in the sealing face (9) in moving direction in front of the low pressure opening (11).

A control plate, for alternatingly fluidically connecting hydrostatic operating chambers, in particular of an oblique axis type axial piston machine, with pressure medium connections, includes a first end face, a second end face, at least a first recess, a first kidney-like control opening, and at least one through-recess. The first face extends transversely to a rotation axis. The second face faces away from the first face. The first recess is bounded in the first end face by the first control opening, and at least partially forms the at least one through recess, which extends toward the second end face from the first end face at an end portion of the first control opening, and which is arranged in or counter to a rotation direction of the rotation axis. An oblique axis construction type axial piston machine includes such a control plate.

A hydraulic axial piston machine (1) is described, the machine comprising a housing, a cylinder block (2) rotatably mounted in the housing about an axis or rotation (7) and having at least one cylinder (3), and a valve arrangement (4) between the cylinder block (2) and the housing, the valve arrangement having a first part (4) rotating with the cylinder block (2) and a second part mounted stationary with respect to the housing. Such a machine should have a high efficiency. To this end the first part (4) comprises an elastically deformable spring section (9).

A hydraulic axial piston machine (1) is described, the machine comprising a housing, a cylinder block (2) rotatably mounted in the housing about an axis or rotation (7) and having at least one cylinder (3), and a valve arrangement (4) between the cylinder block (2) and the housing, the valve arrangement having a first part (4) rotating with the cylinder block (2) and a second part mounted stationary with respect to the housing. Such a machine should have a high efficiency. To this end the first part (4) comprises an elastically deformable spring section (9).

A valve plate assembly (1) of a hydraulic axial piston machine is described, the valve plate assembly comprising a wear plate (2) made of a ceramic material surrounded by a compression ring (4). Such a valve plate assembly should be produced and maintained in a cost-effective manner. To this end, the wear plate (2) is connected to a support plate (3) by means of the compression ring (4).

A hydraulic piston machine is described comprising a piston (1) having a hollow (2) secured by a wall (3) and an insert (4) arranged in the hollow. Such a machine should have a high efficiency at low costs. To this end the insert (4) comprises a section (29) which extends out of the hollow (2).

A hydraulic piston machine is described comprising a piston (1) having a hollow (2) secured by a wall (3) and an insert (4) arranged in the hollow. Such a machine should have a high efficiency at low costs. To this end the insert (4) comprises a section (29) which extends out of the hollow (2).

Hydraulic axial piston unit having a rotational group for driving or being driven by a driving shaft, and a tiltable displacement element for adjusting the displacement volume of the rotational group. The rotational group includes a rotatable cylinder block in which working pistons are mounted reciprocally moveable in cylinder bores for conveying hydraulic fluid from a kidney-shaped inlet port to a kidney-shaped outlet port on a valve segment. At least two control ports are located on the valve segment each between the respective circumferential ends of the kidney-shaped inlet port and the outlet port. The control ports can be brought sequentially in fluid connection with the cylinder bores when the cylinder block is rotating. At least one hydraulic fluid injector is connected fluidly to one control port, for sequentially injecting pressurized hydraulic fluid via the control port into the passing cylinder bores. Via the other control port hydraulic fluid can be drained from passing cylinder bores.

A hydraulic motor apparatus includes a motor housing engaged to an end cap having a first porting system and an adapter connected to an external surface of the end cap and having a second porting system. A filter may be attached to the adapter and connected to the second porting system and a pressure reducing valve in the adapter is connected to the second porting system. The assembly may also include a controller operatively connected to the pressure reducing valve and system sensors measuring parameters affected by the output of the hydraulic motor apparatus, whereby the pressure reducing valve is operatively controlled by the controller in response to input from the system sensors.

A hydraulic motor apparatus includes a motor housing engaged to an end cap having a first porting system and an adapter connected to an external surface of the end cap and having a second porting system. A filter may be attached to the adapter and connected to the second porting system and a pressure reducing valve in the adapter is connected to the second porting system. The assembly may also include a controller operatively connected to the pressure reducing valve and system sensors measuring parameters affected by the output of the hydraulic motor apparatus, whereby the pressure reducing valve is operatively controlled by the controller in response to input from the system sensors.