A radial piston hydraulic device distributed by pilot operated check valves includes a housing, a plurality of piston assemblies, a main shaft, the rotating shaft, first pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies, and second pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies. The housing includes a plurality of piston chambers, a rotating shaft chamber, a high-pressure oil passage, and a low-pressure oil passage. Each of the plurality of piston assemblies is slidable up and down in a corresponding piston chamber of the plurality of piston chambers. The main shaft is rotatably connected to the housing and is connected to the plurality of piston assemblies in a transmission way.

A pump for exerting a compression action on a fluid, includes a casing for rotatably supporting a shaft having an axis; and an actuating device for actuating the fluid, including a reciprocating device movable in an axial direction. A connection device includes a driving device having a circumferential surface eccentrically extending from the axis and which is rotatable together with the shaft. A device for transmitting a driving motion of the eccentric surface to the actuation device includes a body suitable to convert the rotary motion of the eccentric driving surface into said reciprocating axial motion for the actuating device. A motor includes a drive shaft rotated by a fluid device. The fluid device including reciprocatingly movable thrust devices and a transformation device for transforming movement of the thrust devices, into a rotary motion of the drive shaft.

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 (Q.sub.act) is determined, by measuring the volume flow in the fluid passage at a predetermined drive-vector, a computed volume flow (Q.sub.comp) 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 (Q.sub.act) to the computed volume flow (Q.sub.comp).

The present invention relates to a hydraulic device (10) with radial pistons, comprising: a shaft (12) arranged along an axis (1); a cover (13) forming a casing element, the cover and the shaft being free to rotate with respect to one another; a distribution assembly comprising: a multi-lobe cam (14); a cylinder block (15); a distributor (16) configured to exert a thrust force (P) against the cylinder block (15) along the axis (11) of the shaft; an assembly (22) of mechanical bearings comprising at least one mechanical bearing (22a) mounted in radial contact between the cover (13) and shaft (12), said assembly being configured to take up the thrust force (P) exerted by the distributor (16); and a radial contact ball bearing mounted in radial contact between the cover (13) and the shaft (12).

A radial piston motor comprises cylinder-piston units arranged in a star shape, a housing, an output shaft, an inner axial housing collar, an outer axial shaft collar, an output flange, an output shaft, and a brake positioned at least in certain sections between the inner axial housing collar and the outer axial shaft collar. The output flange is attached to the output shaft. The output flange is attached to the shaft collar radially outside the shaft collar.

A radial piston motor comprises cylinder-piston units arranged in a star shape, a housing, an output shaft, an inner axial housing collar, an outer axial shaft collar, an output flange, an output shaft, and a brake positioned at least in certain sections between the inner axial housing collar and the outer axial shaft collar. The output flange is attached to the output shaft. The output flange is attached to the shaft collar radially outside the shaft collar.

The assembly may include a cylinder block, a plurality of pistons, and a holding element, the holding element extending over all or part of the outer periphery of the cylinder block. The holding element may include a plurality of guide portions, each partially blocking a recess of the cylinder block so as to come into contact with a planar end of the crown of a piston to guide in the translation of each piston in their respective recesses. The holding element may include two indexing means cooperating with two indexing means of the cylinder block so as to hold the holding element under a traction force when positioned around the cylinder block.

A radial piston hydraulic device distributed by pilot operated check valves includes a housing, a plurality of piston assemblies, a main shaft, the rotating shaft, first pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies, and second pilot operated check valves having a same number with the plurality of piston assemblies and one-to-one corresponding to the plurality of piston assemblies. The housing includes a plurality of piston chambers, a rotating shaft chamber, a high-pressure oil passage, and a low-pressure oil passage. Each of the plurality of piston assemblies is slidable up and down in a corresponding piston chamber of the plurality of piston chambers. The main shaft is rotatably connected to the housing and is connected to the plurality of piston assemblies in a transmission way.

Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.