Abstract: The invention relates to an axial piston machine in which pistons carry out a stroke movement in cylinders and in which the pistons have a seal ring receptacle for a seal ring. In order to improve robustness, wear resistance, friction and stick-slip behavior, according to the invention, the seal ring is spherical, wherein the curvature radius of the seal ring, which is spherical in regions, substantially corresponds to half the diameter of the cylinder inner wall.

Abstract: The present invention relates to a method for determining a present state of wear of a hydrostatic machine during the operation of the hydrostatic machine. The hydrostatic machine comprises a drive with variable rotational speed and a hydrostatic pump, wherein the drive is designed to drive the hydrostatic pump for generating a volume flow of a fluid, and wherein the hydrostatic machine is connected to a fluid transport channel in which the fluid is transported in a manner driven by the hydrostatic machine. The method has a step for determining a first torque of the drive at a specified drive vector. Furthermore, the method has a step for ascertaining a second torque of the drive at the specified drive vector using a first calculation method, and in addition, the method has a step for determining the present state of wear of the hydrostatic machine using a second calculation method, in order to compare the first determined torque and the second ascertained torque to one another.

Abstract: A method for determining a current wear (w) of a hydrostatic pump, particularly of a radial piston pump, with a variable-speed drive, where the pump is connected to a fluid passage, in which a fluid is pumped by the pump to create a current actual volume flow in the fluid passage. A current actual volume flow (Qact) is determined, by measuring the volume flow in the fluid passage at a predetermined drive-vector, a computed volume flow (Qcomp) is determined, by a first computational method, at the predetermined drive-vector, and the current wear (w) of the pump is determined, by a second computational method, which relates the current actual volume flow (Qact) to the computed volume flow (Qcomp).

Abstract: An electro-hydrostatic drive for realizing a rapid movement during a rapid movement phase, a force-building movement during a force-building movement phase. The apparatus comprises a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-stream of a hydraulic fluid, a first cylinder with a piston chamber, an rod chamber, and a plunger rod, a reservoir, a pressure source, a relief valve, a check valve, a fluid connection between the piston chamber and the hydro-machine, a fluid connection between the rod chamber and the hydro-machine, a fluid connection between the piston chamber and the reservoir, a fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir, a fluid connection, through the relief valve, between the reservoir and the pressure source.

Abstract: The invention relates to a radial reciprocating engine (1) having cylinders (5) arranged in a cylinder carrier (16) and a piston element (21) arranged in each cylinder (5) that is connected to a guide element (22), wherein the guide element (22) runs on a slide surface (14), whereby a stroke movement is imposed on the piston element (21). Since the piston element (21) is spherical at least in the region of the piston element (21) which seals the inner walls (51) of the cylinder (5) during the stroke movements, a linear seal is created, which enables a more compact design in comparison to radial pumps with cylindrical piston elements.

Abstract: An electro-hydrostatic actuation system and a method for driving a hydraulic actuator, e.g. a hydraulic cylinder, are described, wherein the system comprising a leakage branch, and wherein preferably an additional pump is arranged. The system further comprises a source for providing hydraulic liquid; a high-pressure circuit to direct the hydraulic liquid to a hydraulic actuator, such as e.g. a hydraulic cylinder; a low-pressure circuit having several branches; a main pump for hydraulic liquid arranged in the high-pressure circuit, comprising a housing having a high-pressure section and a low-pressure section, separated by gap sealings, wherein the high-pressure section comprises a first outlet and a second outlet to provide the hydraulic liquid flow in the high-pressure circuit; and wherein the low- pressure section comprises a leakage outlet; an electric motor driving the main pump.

Abstract: Electrohydrostatic drive with an electromechanical drive with a rotating drive shaft and a first receiving unit, wherein the electromechanical drive is arranged in the first receiving unit. Furthermore, the electrohydrostatic drive comprises a pump unit and a second receiving unit, wherein the pump unit is arranged in the second receiving unit and the second receiving unit contains a transport fluid, and the first receiving unit and the second receiving unit are arranged in contact with one another, with the result that the electromechanical drive and the pump unit are connected to one another via the drive shaft.

Abstract: A method for determining a current wear (w) of a hydrostatic pump, particularly of a radial piston pump, with a variable-speed drive, where the pump is connected to a fluid passage, in which a fluid is pumped by the pump to create a current actual volume flow in the fluid passage. A current actual volume flow (Qact) is determined, by measuring the volume flow in the fluid passage at a predetermined drive-vector, a computed volume flow (Qcomp) is determined, by a first computational method, at the predetermined drive-vector, and the current wear (w) of the pump is determined, by a second computational method, which relates the current actual volume flow (Qact) to the computed volume flow (Qcomp).

Abstract: An electro-hydrostatic drive for realizing a rapid movement during a rapid movement phase, a force-building movement during a force-building movement phase. The apparatus comprises a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-stream of a hydraulic fluid, a first cylinder with a piston chamber, an rod chamber, and a plunger rod, a reservoir, a pressure source, a relief valve, a check valve, a fluid connection between the piston chamber and the hydro-machine, a fluid connection between the rod chamber and the hydro-machine, a fluid connection between the piston chamber and the reservoir, a fluid connection between the rod-chamber-side port of the hydro-machine and the reservoir, a fluid connection, through the relief valve, between the reservoir and the pressure source.

Abstract: The invention relates to a hydrostatic radial piston motor, in particular a hydrostatic radial piston motor for actuating a differential cylinder. According to the invention, the hydrostatic motor in radial piston configuration comprises a control stud in a housing, the hydrostatic motor having three hydraulic working connections. The first working connection can be connected to the piston-end of a differential cylinder, while the second working connection can be connected to the rod-end of the differential cylinder. Finally, the third working connection can be connected to a tank. Owing to this arrangement, the differential cylinder can be directly operated with the aid of a single hydrostatic motor, with it being possible to forgo interposing proportional or control valves.