A hydrostatic axial piston machine includes a double-acting actuating cylinder configured to adjust the piston displacement. The actuating cylinder has two actuating chambers that are connected to two spatially separated cartridge valves. The two cartridge valves are inserted obliquely into a wall section of the axial piston machine. The wall section on the one hand forms a wall of the housing of the axial piston machine and on the other hand forms a wall of the actuating cylinder.

The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures (40, 42, 44), and a cylinder-capacity selector (21) suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure (42) is connected to one of the main ducts (2), while the first and third enclosures (40, 44) are connected to the other main duct (1), and a small cylinder capacity configuration in which the second and third enclosures (42, 44) are connected to said one of the main ducts (2), while the first enclosure is connected to the other main duct (1). The machine further comprises a safety valve (150) having at least a first port (56) connected to said one of the main ducts (2), and a second port (58) connected to the third enclosure (44). Said safety valve is suitable, when the cylinder-capacity selector (21) is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports (56, 58) from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports (56, 58).

A radial piston device includes a housing, a pintle attached to the housing and having a pintle shaft, a rotor rotatably mounted on the pintle shaft and having cylinders, pistons displaceably received in the cylinders, and a drive shaft coupled to the rotor and rotatably supported within the housing. The radial piston device includes mechanisms for reducing a pressure loss of hydraulic fluid flowing into the pintle shaft.

An axial piston machine may include a rotor having a shaft rotatably mounted in a housing. A plurality of cylinders may be arranged annularly around the rotor. A plurality of pistons may each be disposed within each of the plurality of cylinders and may be constructed and arranged to selectively translate within each of the plurality of cylinders. Each of the plurality of cylinders may be disposed within a cylinder head and may be in operative communication with an inlet opening defined in the cylinder head and at least one outlet opening defined in the housing. An auxiliary outlet rotary slide valve may be operatively connected to the shaft in a rotationally fixed manner. The auxiliary outlet rotary slide valve may comprises an auxiliary outlet rotary opening constructed and arranged to connect to a vent duct of one of the plurality of cylinders based on an angle of rotation, and may vent the one of the plurality of cylinders. At least a portion of the auxiliary outlet rotary slide valve may comprise a material constructed and arranged to reduce a sliding friction resistance, and wherein the material comprises one of a carbon containing material or a polymer containing material.

An axial piston machine may include a shaft and a housing surrounding at least a portion of the shaft. A cylinder arrangement may be disposed within the housing in a circular manner. The cylinder arrangement may include a plurality of cylinders and a plurality of pistons each extending within each of the plurality of cylinders and may be constructed and arranged to drive the shaft. The plurality of cylinders may each include an expansion volume with an inlet and at least one outlet opening for a working medium. A cylinder head may be provided on the housing and may be constructed and arranged to close the plurality of cylinders of the cylinder arrangement. A cavity may be defined around the shaft in a central region of the cylinder arrangement and may be in operative communication with a plurality of auxiliary outlet openings of the expansion volume of each of the plurality of cylinders via a temporary connection. A cylindrical roller slider may rotate within the cavity in the central region of the cylinder arrangement and may be constructed and arranged to drive the shaft. A temporary connection between the cavity and the expansion volume of each of the plurality of cylinders may be formed by at least one of a channel through the cylindrical roller slider and a recess on an outside surface of the cylindrical roller slider. The recess may extend laterally from a casing of the cylindrical roller slider at a height of the plurality of auxiliary outlet openings in each of the plurality of cylinders and at a distance to the cavity in the central region of the cylinder arrangement.

A hydrostatic axial piston machine includes a double-acting actuating cylinder configured to adjust the piston displacement. The actuating cylinder has two actuating chambers that are connected to two spatially separated cartridge valves. The two cartridge valves are inserted obliquely into a wall section of the axial piston machine. The wall section on the one hand forms a wall of the housing of the axial piston machine and on the other hand forms a wall of the actuating cylinder.

A hydrostatic radial piston machine is useable inversely. The hydrostatic radial piston machine has a distributor in which a flushing valve, a pressure-maintaining valve connected downstream of the flushing valve, and two nonreturn valves are arranged.

A radial piston device includes a housing, a pintle attached to the housing and having a pintle shaft, a rotor rotatably mounted on the pintle shaft and having cylinders, pistons displaceably received in the cylinders, and a drive shaft coupled to the rotor and rotatably supported within the housing. The radial piston device includes mechanisms for reducing a pressure loss of hydraulic fluid flowing into the pintle shaft.

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.

A multi piston machine includes a rotor, pistons, a first control valve, and a second control valve. The pistons abut against a cam surface with multiple lobes. The machine is switchable between at least three non-zero displacement volumes using the first and the second control valves. The first control valve is connected to a first and a third fluid chamber. The second control valve is connected to a second and a fourth fluid chamber. The first and the second control valve are connected to first and the second working port respectively. A third number of second control openings is twice a second number of the lobes. There is a first and a second group of the second control openings. Adjacent second control openings belong to a different first or second group. The second control openings of the first group are either connected to the first or the second fluid chamber.