A hydraulic pump/motor includes: a cylinder block rotating about a rotation axis; a piston in a cylinder bore; and a valve plate facing a cylinder port. The valve plate includes: a high pressure port through which hydraulic oil discharged from the cylinder port flows; a low pressure port through which the oil to be sucked into the cylinder port flows; a region disposed between the high and low pressure ports in a circumferential direction of the rotation axis and including a top dead center position facing the cylinder port of the cylinder bore in which the piston moved to a top dead center is disposed; and a residual pressure release port between the top dead center position and the low pressure port in the region. The residual pressure release port includes first and second ports disposed at a positions different from each other in the radial direction of the rotation axis.

Axial piston machine comprising a drive shaft, a drive mechanism that is connected thereto for conjoint rotation and comprises one or more drive-mechanism pistons, the piston stroke of which can be set by a swash plate, at least one return spring acting on the swash plate and a setting piston supporting on the swash plate, the axial piston machine comprising at least one control or regulating valve or at least one control or regulating unit, characterized in that a setting piston is guided in the connecting plate and a setting lever acts as a coupling member between the setting piston and the swash plate and the setting-piston axis and the setting-lever axis are positioned in a plane E1, in particular in a half plane E1* extending from the drive-shaft axis M.

A thrust bearing assembly is provided for the pistons of a hydrostatic drive motor. The thrust bearing assembly includes first and second retainer components removably interconnected to form a retainer assembly, a thrust bearing captured between and encompassed by the first and second retainer components, and locking tangs extending outward from the first and second retainer components. Corresponding catches are formed on the internal surface of the housing to engage the locking tangs when the thrust bearing assembly is installed in the housing.

A gear shaft assembly for a hydraulic unit is disclosed which includes a gear shaft including a main body portion having a central axis, an outer periphery, an inner periphery and a medial region extending between the outer periphery and the inner periphery, the inner periphery including an annular bearing surface that circumscribes a cylindrical cavity dimensioned to accommodate a roller bearing assembly, and an elongated axial shaft portion extending distally from the main body portion, and a roller bearing assembly arranged within the cylindrical cavity of the main body portion of the gear shaft and including a plurality of circumferentially arranged roller bearing elements in rolling contact with the annular bearing surface.

A flow divider assembly for use with a hydraulic pump provides flow to separate drive motors for use in a vehicle or other application. A pair of flow divider motors may be mounted on a block and have a common axis of rotation. The ratio between the two may be controlled by adjustment of the angles of the respective thrust bearings of the flow divider motors. A valve may connect the outlet of one of the flow divider motors or the outlet of the other flow divider motor. passage to the second outlet passage. Additional bypass valves may be provided to permit direct connection between the hydraulic pump and the separate drive motors.

A hydrostatic axial piston machine includes a pot-like housing, a connection plate that closes the pot-like housing, a rotatably mounted cylinder drum, and pistons arranged in cylinder chambers of the cylinder drum. The cylinder chambers are each alternately connected via a cylinder chamber opening to a low-pressure control opening and a high-pressure control opening of a resting control part. The control part has two switching regions located between the low-pressure and high pressure control openings. A piston reverses its movement direction in a dead center within the two switching regions. In the switching region, the cylinder chambers are connected via a connecting line to a fluid volume arranged in the housing. The fluid volume extends between the connection plate and the housing such that it is sealed to an interior by the connection plate and the housing.

A hydraulic motor includes a motor mechanism that rotates by hydraulic liquid that is supplied/discharged from a hydraulic liquid pressure source through one of a first motor passage and a second motor passage. The hydraulic motor comprises a casing that defines a casing chamber which accommodates the motor mechanism, and a flushing passage that is in communication with the casing chamber and extracts a portion of the hydraulic liquid from a low pressure side among the first motor passage and the second motor passage and leads it to the casing chamber.

A hydrostatic axial piston machine includes a pot-like housing, a connection plate that closes the pot-like housing, a rotatably mounted cylinder drum, and pistons arranged in cylinder chambers of the cylinder drum. The cylinder chambers are each alternately connected via a cylinder chamber opening to a low-pressure control opening and a high-pressure control opening of a resting control part. The control part has two switching regions located between the low-pressure and high pressure control openings. A piston reverses its movement direction in a dead center within the two switching regions. In the switching region, the cylinder chambers are connected via a connecting line to a fluid volume arranged in the housing. The fluid volume extends between the connection plate and the housing such that it is sealed to an interior by the connection plate and the housing.

A hydraulic motor includes a motor mechanism that rotates by hydraulic liquid pressure led from a hydraulic liquid pressure source. The hydraulic motor includes a casing that defines a casing chamber which accommodates the motor mechanism, a brake mechanism that brakes the rotation of the motor mechanism, a brake release actuator that releases the braking of the brake mechanism by a brake release pressure led from the hydraulic liquid pressure source, and a throttle passage that is in communication with the casing chamber and extracts a portion of hydraulic liquid that is led into the brake release actuator and leads it to the casing chamber.