A rotary fluid pump-motor includes first and second rotor assemblies and a bent cylinder sleeve. The first rotor assembly includes a first rotor, a piston cylinder, and a flange ring with an inclined guide surface. The second rotor assembly includes a second rotor and a piston. The first and second rotors are rotatably movable about inclined first and second rotor axes, respectively. The bent cylinder sleeve receives the piston cylinder and the piston therein through respective sleeve openings to define a piston chamber therebetween. The bent cylinder sleeve is in at least intermittent contacting relationship with the flange ring's inclined guide surface and rotatably movable about the first rotor axis with respect to the inclined guide surface such that the bent cylinder sleeve moves along the first rotor axis relative to the piston cylinder based upon its circumferential position along the inclined guide surface to correspondingly vary the piston chamber's volume.

A rotary fluid pump-motor includes first and second rotor assemblies and a bent cylinder sleeve. The first rotor assembly includes a first rotor, a piston cylinder, and a flange ring with an inclined guide surface. The second rotor assembly includes a second rotor and a piston. The first and second rotors are rotatably movable about inclined first and second rotor axes, respectively. The bent cylinder sleeve receives the piston cylinder and the piston therein through respective sleeve openings to define a piston chamber therebetween. The bent cylinder sleeve is in at least intermittent contacting relationship with the flange ring's inclined guide surface and rotatably movable about the first rotor axis with respect to the inclined guide surface such that the bent cylinder sleeve moves along the first rotor axis relative to the piston cylinder based upon its circumferential position along the inclined guide surface to correspondingly vary the piston chamber's volume.

The disclosure relates to a hydrostatic axial piston machine having a housing, having a drive shaft, to which a flange disc is fastened in a rotationally fixed manner, and having a swash plate, to which a rotor disc, driven by the drive shaft or the flange disc, is rotatably mounted, and having a plurality of displacement units arranged distributed between the flange disc and the rotor disc and around the axis of the drive shaft, each displacement unit comprising a cylinder sleeve and a piston which extends into the cylinder sleeve and has a ball head and a spherical joint head which extends into the cylinder sleeve, wherein during operation, the piston plunges more or less far into the cylinder sleeve.

The disclosure relates to a hydrostatic axial piston machine having a housing, having a drive shaft, to which a flange disc is fastened in a rotationally fixed manner, and having a swash plate, to which a rotor disc, driven by the drive shaft or the flange disc, is rotatably mounted, and having a plurality of displacement units arranged distributed between the flange disc and the rotor disc and around the axis of the drive shaft, each displacement unit comprising a cylinder sleeve and a piston which extends into the cylinder sleeve and has a ball head and a spherical joint head which extends into the cylinder sleeve, wherein during operation, the piston plunges more or less far into the cylinder sleeve.

A hydraulic pressure exchanger comprising a drum rotatable about an axis, a front plate arrangement having a front plate and a pressure shoe, said drum including a plurality of working cylinders, each working cylinder having a front opening and, during rotation of this drum, said front opening sliding over said pressure shoe along a path, said pressure shoe having at least two kidney-shaped openings, said kidney-shaped openings being arranged in said path. The hydraulic pressure exchanger should be operated with low noise. To this end said pressure shoe is arranged between said drum and said front plate and comprises at least one pressure cylinder arranged between two neighboring kidney-shaped openings, a piston being arranged in said pressure cylinder and resting against said front plate, said pressure cylinder being connected with a supply opening in a side of the pressure shoe opposite said front plate, said opening at least partly overlapping said path.

A hydraulic pressure exchanger comprising a drum rotatable about an axis, a front plate arrangement having a front plate and a pressure shoe, said drum including a plurality of working cylinders, each working cylinder having a front opening and, during rotation of this drum, said front opening sliding over said pressure shoe along a path, said pressure shoe having at least two kidney-shaped openings, said kidney-shaped openings being arranged in said path. The hydraulic pressure exchanger should be operated with low noise. To this end said pressure shoe is arranged between said drum and said front plate and comprises at least one pressure cylinder arranged between two neighboring kidney-shaped openings, a piston being arranged in said pressure cylinder and resting against said front plate, said pressure cylinder being connected with a supply opening in a side of the pressure shoe opposite said front plate, said opening at least partly overlapping said path.

A hydraulic device comprises an outer surface of a rotor rotating and facing an outer surface of a port member. The rotor has a plurality of cylinders disposed about an axis and cooperating pistons. The cylinders communicate with respective open ends at the rotor outer surface. Each open end alternatingly communicates with high and low pressure ports. Each two successive cylinders are interconnected via a fluid displacement member having first and second openings communicating with each respective cylinder and a closure element that obstructs either the first or second opening if the pressure in the cylinder that communicates with the second opening is higher or lower than the pressure in the cylinder that communicates with the first opening, respectively. The first opening and the second opening of each two fluid displacement members which communicate with one cylinder are fluidly connected with that cylinder at opposite sides of a flow resistance.

A hydraulic device comprises an outer surface of a rotor rotating and facing an outer surface of a port member. The rotor has a plurality of cylinders disposed about an axis and cooperating pistons. The cylinders communicate with respective open ends at the rotor outer surface. Each open end alternatingly communicates with high and low pressure ports. Each two successive cylinders are interconnected via a fluid displacement member having first and second openings communicating with each respective cylinder and a closure element that obstructs either the first or second opening if the pressure in the cylinder that communicates with the second opening is higher or lower than the pressure in the cylinder that communicates with the first opening, respectively. The first opening and the second opening of each two fluid displacement members which communicate with one cylinder are fluidly connected with that cylinder at opposite sides of a flow resistance.

Methods and systems for a variable balancing piston motor are described. In one example, a hydraulic displacement motor includes a valve plate coupled to at least one piston of a cylinder block, the valve plate comprising a plurality of grooves fluidly coupled to a passage comprising a valve.

Methods and systems for a variable balancing piston motor are described. In one example, a hydraulic displacement motor includes a valve plate coupled to at least one piston of a cylinder block, the valve plate comprising a plurality of grooves fluidly coupled to a passage comprising a valve.