A radial piston hydraulic motor comprising a hollow rotating shaft inside the motor, which rotating shaft is arranged to rotate around its axial central axis A for providing torque from the radial piston hydraulic motor, wherein the rotating shaft comprises a piston frame with pistons, which are arranged to move radially, the piston frame comprises a distribution surface, which is a flat surface in parallel plane with the radial movement of the pistons, and a first inner surface extending in axial direction around the axial central axis A, wherein the rotating shaft comprises a half shaft having a second inner surface extending in axial direction around the axial central axis A, wherein piston frame and the half shaft are arranged adjacent to each other so that the first inner surface and the second inner surface form a surface, in axial direction, forming a cavity inside the rotating shaft for receiving a drive shaft.

A hydrostatic axial piston machine (1) has a cylinder barrel (7) with a plurality of piston bores having pistons (10) fastened in an articulated manner to a drive flange (3). For articulated fastening of the pistons (10) to the drive flange (3), ball joints (20) are provided that are formed by a spherical cap-shaped receptacle socket (3a) in an end surface (3b) of the drive flange (3) and a ball head (10a) that is operatively connected with the piston (10). The receptacle sockets (3a) are each in the form of hemispheres that extend to the ball equator, and on one end surface (3b) of the drive flange (3), in the vicinity of the receptacle sockets (3a), there is a retaining web (30) that extends beyond the ball equator of the hemisphere to grip the ball head (10a) at an angle of greater than 180°.

A hydrostatic actuator and an arrangement for attaching it to a receiving component are provided. The hydrostatic actuator has a master cylinder containing a housing and a piston movable axially within the housing which acts on a pressure chamber filled with a pressurizing agent. The piston is driven by a rotary-driven electric motor having a stator and a rotor, by a rolling planetary transmission that converts the rotary drive to an axial motion. In order to be able to produce such a hydrostatic actuator with little need for construction space, cost-effectively and with better quality, a supporting of the rolling planetary transmission is simplified, and the cooling and shielding of an electronic controller and the pressure behavior of the hydrostatic actuator is improved.

A sliding member including, a support layer and a sliding layer provided on a side of one end surface of the support layer configured to slide on a mating member, the sliding layer having a hardness set higher toward an outer side than at a center in an axial direction.

A sliding member including, a support layer and a sliding layer provided on a side of one end surface of the support layer configured to slide on a mating member, the sliding layer having a hardness set higher toward an outer side than at a center in an axial direction.

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 hydraulic piston (1) constitutes a hydraulic chamber (5) with a cylinder (4) and has a cylindrical body (6) connectedfrom the side of the chamber (5)by a link-stop valve (3) to a cooling and lubricating gasket valve (2) which is passed right through by a flow calibration opening (27), the valve (2) being able to move in longitudinal translation over a short stroke with respect to the body (6) or to be held at a distance from the body (6) by the valve link-stop (3), a valve return spring (30) tending to move the valve (2) away from the cylindrical body (6).

A hydrostatic positive-displacement machine, in particular a hydrostatic axial piston machine, having a cylinder drum with at least one cylinder, in which a longitudinally displaceable piston is received, which is supported directly or indirectly by a support portion on an inclined plane of the positive-displacement machine. An outer circumferential surface portion of the piston is in bearing contact with an inner circumferential surface portion of the cylinder.

The hydraulic piston forms a hydraulic chamber with a cylinder and has a cylindrical body which receives a seal and whose external cylindrical surface is housed with little clearance in the cylinder in such a manner as to leave an interstitial space, the cylindrical body being run through by a cooling and lubrication pipe which can be opened or closed by a cooling and lubrication valve which is moved by translation by a valve-actuator in such a manner that fluid can pass via a flow calibration opening from the hydraulic chamber to the interstitial space when the pressure existing in the hydraulic chamber is low and cannot pass when the pressure in the chamber is high.

An axial hydraulic pump-motor, in which a cylinder block having a plurality of cylinder bores on a valve plate having a high-pressure side port and a low-pressure side port for controlling an amount of reciprocation of a piston in each of the cylinder bores, the hydraulic pump-motor includes: a residual pressure release port provided on the valve plate and communicating until the cylinder bore on a top dead center side communicates with the low-pressure side port; a residual pressure acquisition portion obtaining a value of a residual pressure in the cylinder bore on the top dead center side; and a directional switching valve switching a flow path between the residual pressure release port and an hydraulic oil tank and a flow path between the residual pressure release port and the low-pressure side port.