A hydraulic machine with oscillating axial cylinders includes a plurality of oscillating axial cylinders, put in synchronous rotation between a first rotating element, a rotating disc, which supports one end of the cylinder, bottom or piston, and a second rotating element, a rotating barrel, which supports the opposite end of the cylinder; each cylinder is connected to said rotating elements with a ball joint towards each of them; each ball joint is holed to allow for the passage and the feeding/discharge through it of the hydraulic liquid. At least the bottom or the piston is connected to the respective rotating element with a ball joint having a spherical surface with a diameter equal to or greater than the cylinder bore.

A hydrostatic axial piston machine has a drive shaft penetrating a housing on either side. In this case, the mechanically weaker of the two shaft ends is strengthened by an undercut being eliminated, said undercut defining the minimum diameter of the shaft end and thus of the entire drive shaft. Instead, the strength of the relevant shaft end is increased by a displacement of a circular bearing surface for a rolling bearing radially outwardly and away from the rolling bearing. In this case, the circular bearing surface is displaced below a compression spring which clamps the cylinder drum against a distributor plate. The resulting spacing between the circular bearing surface and the rolling bearing remaining in place is bridged by a sleeve or by a ring. A concave rounded shaft shoulder is simply formed below the sleeve and/or the ring.

An inclined-axis axial piston machine includes a housing, a drive shaft and a cylinder barrel. The drive shaft is mounted in the housing so as to be rotatable with respect to a first axis of rotation and is integral with a flange. Each piston is coupled to the flange via a ball joint. A multiplicity of counting perforations are arranged in a periodically distributed and continuous manner over an outer circumferential surface of the flange. The housing accommodates a sensor arranged opposite the counting perforations such that rotation of the drive shaft causes a signal change at the sensor. Each counting perforation is formed integrally from the flange, in the form of a recess having a single continuous perimeter. A side wall of the recess, starting from the perimeter, extends uninterruptedly, without sharp bends or offsets, over the entire circumference of the perimeter.

A piston pump includes a first biasing mechanism configured to bias a swash plate in accordance with supplied control pressure, a second biasing mechanism configured to bias the swash plate against the first biasing mechanism, and a regulator configured to control the control pressure led to the first biasing mechanism in accordance with discharge pressure of the piston pump, wherein the second biasing mechanism has a pressure chamber to which the discharge pressure is led, and a control piston configured to be biased toward the swash plate by the discharge pressure led to the pressure chamber, and the regulator has a biasing member configured to bias the control piston toward the swash plate, and a control spool configured to be moved in accordance with biasing force of the biasing member, the control spool being configured to adjust fluid pressure.

A hydrostatic positive displacement machine has an adjustable swept volume, and has a lifting element, a rotor with positive displacement elements supported on the lifting element, and a hydraulic adjusting device that adjusts the swept volume and includes an adjusting piston that is mounted in or on a cylinder, is movable axially rectilinearly in relation to the cylinder, and is adjacent to a pressurizable adjusting chamber. A bearing gap is formed between a circular-cylindrical bearing surface of the adjusting piston and a circular-cylindrical bearing surface of the cylinder. The adjusting piston is mounted hydrostatically, wherein at least three pressure pockets are distributed uniformly in a row over the circumference of a bearing surface. Pressure fluid flows into each pressure pocket via a fixed throttle, which is assigned only to the respective pressure pocket, and flows out of each pressure pocket via the bearing gap.

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 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 present invention relates to a method of manufacturing a drum of an axial piston machine by machining a cylindrical round metal, with the machining comprising a forging and with at least one structural element of the drum being produced or prefabricated by the forging.

A piston pump includes a first biasing mechanism configured to bias a swash plate in accordance with supplied control pressure, a second biasing mechanism configured to bias the swash plate against the first biasing mechanism, and a regulator configured to control the control pressure led to the first biasing mechanism in accordance with discharge pressure of the piston pump, wherein the second biasing mechanism has a pressure chamber to which the discharge pressure is led, and a control piston configured to be biased toward the swash plate by the discharge pressure led to the pressure chamber, and the regulator has a biasing member configured to bias the control piston toward the swash plate, and a control spool configured to be moved in accordance with biasing force of the biasing member, the control spool being configured to adjust fluid pressure.

A hydrostatic axial piston machine has a drive shaft penetrating a housing on either side. In this case, the mechanically weaker of the two shaft ends is strengthened by an undercut being eliminated, said undercut defining the minimum diameter of the shaft end and thus of the entire drive shaft. Instead, the strength of the relevant shaft end is increased by a displacement of a circular bearing surface for a rolling bearing radially outwardly and away from the rolling bearing. In this case, the circular bearing surface is displaced below a compression spring which clamps the cylinder drum against a distributor plate. The resulting spacing between the circular bearing surface and the rolling bearing remaining in place is bridged by a sleeve or by a ring. A concave rounded shaft shoulder is simply formed below the sleeve and/or the ring.