A hydraulic radial piston device is provided with a mechanism for reducing pressure pulsations and providing a smooth pressure transition throughout different displacement operations. In certain examples, the hydraulic radial piston device is configured to maintain an amount of precompression and an amount of decompression of hydraulic fluid trapped in a cylinder chamber to be consistent, respectively, throughout different displacement operations.

A hydraulic radial piston device is provided with a mechanism for reducing pressure pulsations and providing a smooth pressure transition throughout different displacement operations. In certain examples, the hydraulic radial piston device is configured to maintain an amount of precompression and an amount of decompression of hydraulic fluid trapped in a cylinder chamber to be consistent, respectively, throughout different displacement operations.

A hydraulic machine (1) comprising first and second brake elements (92, 93), a spring washer (65) tending to urge the first and second brake elements (92, 93) in a braking direction, and a brake release piston (61) configured to act on the spring washer (65) in a direction opposing the braking direction, the hydraulic machine being characterized in that the brake release piston (61) comprises a primary brake release piston (61a) associated with a primary brake release chamber (62a), and a secondary brake release piston (61b) associated with a secondary brake release chamber (62b), said primary and secondary chambers (62a, 62b) extending radially around the shaft (2) in such a manner that projections of the primary brake release chamber (62a) and of the secondary brake release chamber (62b) onto a plane perpendicular to a longitudinal axis (X-X) defined by the axis of rotation of the hydraulic machine (1) are superposed, at least in part.

A hydraulic machine (1) comprising first and second brake elements (92, 93), a spring washer (65) tending to urge the first and second brake elements (92, 93) in a braking direction, and a brake release piston (61) configured to act on the spring washer (65) in a direction opposing the braking direction, the hydraulic machine being characterized in that the brake release piston (61) comprises a primary brake release piston (61a) associated with a primary brake release chamber (62a), and a secondary brake release piston (61b) associated with a secondary brake release chamber (62b), said primary and secondary chambers (62a, 62b) extending radially around the shaft (2) in such a manner that projections of the primary brake release chamber (62a) and of the secondary brake release chamber (62b) onto a plane perpendicular to a longitudinal axis (X-X) defined by the axis of rotation of the hydraulic machine (1) are superposed, at least in part.

An object is displaced alternately in opposite directions, using a hydraulic power unit having a rotatable body which includes the shaft of a hydraulic machine having electronically commutated valves. A motor drives the rotatable body. The hydraulic machine drives an actuator to displace the object in use. Energy is transformed from rotational kinetic energy of the rotatable body to elastic strain energy or elastic strain and gravitational potential energy of the object during a pumping phase and rotation of the rotatable body slows, but does not change direction. The potential energy then drives the hydraulic machine to motor and the rotatable shaft speeds up again, storing rotational kinetic energy. The displacement of the hydraulic machine is controlled throughout to match a time varying demand taking into account the varying speed of rotation of the rotatable shaft. The motor provides energy to compensate for losses and the process can repeat cyclically.

A hydraulic motor for vehicle wheel includes a hydrodynamic element, a reaction element, an oil distributor rotating as one with the reaction element, and a brake mounted between the two elements to oppose the rotational movement. The hydrodynamic element has a flange that surrounds the oil distributor. On its radially exterior face, it has means for rotationally coupling with the rotary discs of the brake. The brake is thus positioned around the distributor.

A hydraulic motor for vehicle wheel includes a hydrodynamic element, a reaction element, an oil distributor rotating as one with the reaction element, and a brake mounted between the two elements to oppose the rotational movement. The hydrodynamic element has a flange that surrounds the oil distributor. On its radially exterior face, it has means for rotationally coupling with the rotary discs of the brake. The brake is thus positioned around the distributor.

The synchronized roller with freewheels includes a central body which exposes an outer cylindrical rolling surface provided to roll between two rolling tracks lined with a synchronizing unit, each end of the body presenting a smooth axis about which a synchronizing pinion is freely rotatable, the axis having a pinion axial stop unit which prevents the pinion from emerging from the pinion, while a roller axial guide bears on the central body and on the rolling tracks to keep the outer cylindrical rolling surface approximately centered on the tracks.

A hydraulic piston machine including a housing, a shaft that is able to rotate relative to the housing, and a cam secured to one of the housing or the shaft. A cylinder block includes pistons that are able to move in the cylinder block opposite the cam in order to generate relative rotation between the cylinder block and the cam. The cylinder block is linked in rotation to the other of the shaft or the housing. A mechanism forms rotation guide bearings for guiding the rotation of the shaft relative to the housing, which mechanism includes a tapered plain bushing interposed between a housing element and an element linked in rotation with the shaft and in which the tapered plain bushing includes a radial through-slit extending through the entire radial dimension of the bushing.

A hydraulic piston machine including a housing, a shaft that is able to rotate relative to the housing, and a cam secured to one of the housing or the shaft. A cylinder block includes pistons that are able to move in the cylinder block opposite the cam in order to generate relative rotation between the cylinder block and the cam. The cylinder block is linked in rotation to the other of the shaft or the housing. A mechanism forms rotation guide bearings for guiding the rotation of the shaft relative to the housing, which mechanism includes a tapered plain bushing interposed between a housing element and an element linked in rotation with the shaft and in which the tapered plain bushing includes a radial through-slit extending through the entire radial dimension of the bushing.