A hydraulic machine including: a casing rotatably mounted relative to a shaft; first brake means constrained to rotate with the casing; second brake means constrained to rotate with the shaft, and adapted to co-operate with the first brake means; a braking piston associated with return means and tending to exert a braking force; and a brake-release chamber adapted to be connected to a pressure force so as to apply a brake-release pressure selectively to the braking piston, so as to enable the first and second brake means to be separated; said hydraulic machine including a sweeping channel arranged in the shaft so as to define a leakage flow between the brake-release chamber and an internal volume of the casing.

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 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 application is directed to a system for converting linear motion to rotary motion. The system includes at least first and second cylinders. The first and second cylinders are in fluid communication with each other. The system also includes a first piston. The first piston is slidably disposed in the first cylinder. The system further includes a second piston. The second piston is slidably disposed in the second cylinder. The first and second cylinders contain an incompressible fluid. The first piston is in operative connection with the second piston such that movement of the first piston in a first direction causes movement of the second piston in a second direction, wherein the second direction is opposite the first direction.

A rotary hydraulic machine with radial pistons comprising: a rotating shaft (2); a cylinder-housing body (3), having a plurality of housing seatings (4) arranged radially at equal distances from the rotation axis (R) of the rotating shaft (2); a cylinder (5) housed in each of said plurality of housing seatings (4) and rotating relative to the same around an axis (C) concentric with said rotation axis (R) of the rotating shaft (2); a piston (6) slidable in each cylinder (5) and coupled to a crank (7) of the rotating shaft (2); a supply conduit (12), for each cylinder (5), provided with a seal (120) arranged to enable a sealed connection between the supply conduit (12) and the respective cylinder (5). Each seal (120) comprises: a first ring (121), arranged at an end of the supply conduit (12) and placed in contact with the cylinder (5); a second ring (122), concentric to the first ring (121) and interposed between the supply conduit (12) and the first ring (121), wherein the second ring (122) is coupled by interference with the first ring (121) and is inserted by interference into the supply conduit (12) in such a way as to prevent a rotation of the first ring (121) with respect to the supply conduit (12) around a common axis (X).

The present application is directed to a system for converting linear motion to rotary motion. The system includes at least first and second cylinders. The first and second cylinders are in fluid communication with each other. The system also includes a first piston. The first piston is slidably disposed in the first cylinder. The system further includes a second piston. The second piston is slidably disposed in the second cylinder. The first and second cylinders contain an incompressible fluid. The first piston is in operative connection with the second piston such that movement of the first piston in a first direction causes movement of the second piston in a second direction, wherein the second direction is opposite the first direction.

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.

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 low-energy and high pressure, hydraulic, pneumatic engine contains: a casing device, two main-cylinder devices, a holder device, two main-crankshaft devices, two recycle-valve devices, two swing-arm devices, two movable-valve devices, two recycle-cylinder devices, two recycle-crankshaft devices, and two umbrella-shaped gear devices. The engine operates without using gasoline or diesel, thus avoiding discharge of harmful substance or gas and pollution. The high pressure gas forces the hydraulic oil without using gasoline or diesel so as to start the engine, and the hydraulic oil recycles and reuses repeatedly, thus obtaining environmental protection. And the high pressure gas forces the hydraulic oil so as to circulate the hydraulic oil, and the communication of the low-energy and high pressure and the low pressure matches with the circulation space of the fluid operation to produce the torque, hence four strokes cycle of intake, compression, combustion and exhaust are not required.