A selection system, comprising: a sheath defining an internal housing extending in a longitudinal direction; a link rod disposed in said internal housing, and extending in the longitudinal direction; and a selection slide mounted to slide in the internal housing, about the link rod; the link rod being held stationary relative to the sheath against movement in translation in the longitudinal direction by stop means; the system being characterized in that the stop means comprise: a base that is a body of revolution and includes a conical portion; and a shell comprising two shell portions each including a conical portion configured to come to bear in plane manner against the conical portion of the base.

An injector generator for use in geomechanical pumped storage systems includes a power end and a fluid end. The fluid end has one or more fluid chambers each having a fluid inlet and outlet that are controlled by rotary valves. The fluid end can function as a pump or as a motor driven by fluid pressure from the geomechanical storage formation.

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 motor (10) to be driven by a pressurized fluid includes a manifold (16) with an arcuate surface (20) defining a valve opening (22) surrounded by a sealing surface. A cylinder (26) has an aperture (30) cooperating with the arcuate surface (20). The cylinder (26) is pivotally mounted so as to be pivotable between a neutral state in which the aperture faces the sealing surface, an inlet state in which the aperture (30) is in fluid connection with the valve opening (22), and an exhaust in which the aperture (30) is in fluid connection with a drainage volume. A piston (34), deployed in the cylinder (26), is driven to extend by pressure within the cylinder. The piston is linked to a crank (36) so that rotation of a crankshaft (38) causes a cyclic motion of the piston (34) and cylinder (26) from the inlet state for an extension power stroke of the piston (34), through the neutral state and to the exhaust state for a return motion of the piston (34). The pivot axis of the cylinder, preferably implemented using a pivot axle (32), is located between the crankshaft axis and the arcuate surface (20).

A hydraulic machine includes radial cylinders including, oscillating radial cylinders arranged in a crown or star of cylinder-piston units, the pistons of the groups are made slidable on a crankshaft or with a cam, or on interposed members concentric to it, and realizing the reciprocating motion in the oscillating cylinders. The oscillating cylinders are placed in contact with a surface of distribution concentric or corresponding to the surface of oscillation of the respective cylinder on which a distributor body is placed separate from the machine body and housed in a seat in the body, or part fixed to the body, of the hydraulic machine, and each distributor body is mobile in its seat under the action of the pressure of liquid in connection on the back surface of the distributor body against the surface of distribution of the oscillating radial cylinder subject to the distribution.

An assembly including a hydraulic device around a second axis of rotation by means of a proximal rolling-element bearing and a distal rolling-element bearing, the hydraulic device including a shaft, a multi-lobe cam, a cylinder block and a distributor, and a pivoting element adapted to be mounted on an axle, and movable in rotation relative to the hydraulic device around a first axis of rotation. Views along a plane defined by the second axis of rotation and the first axis of rotation, the proximal rolling-element bearing and the distal rolling-element bearing are positioned on either side of the first axis of rotation, in that the cylinder block is positioned between the first axis of rotation and the proximal rolling-element bearing.

The hydraulic machine includes a cam and a cylinder block with pistons co-operating with cam lobes, each of which has two ramps extending between top and bottom dead center arcs. The cylinders are connected in alternation to a feed and to a discharge, in sequences separated by switchover stages including an isolation stage during which they are isolated relative to the feed and discharge main ducts. The angular position of the start or of the end of at least one first isolation stage relative to the corresponding dead center arc is different from the angular position of the start or of the end of at least one second isolation stage relative to its corresponding dead center arc, both of these dead center arcs being top dead center arcs or both of them being bottom dead center arcs.

The invention relates to a hydraulic machine (100) comprising:a distribution cover (2.3);a distributor (16);a displacement selection drawer (35) mounted so as to slide between a first position in which the machine is configured to operate with a first displacement and a second position in which the machine is configured to operate with a second displacement different from the first displacement; anda direction changing drawer (26) mounted so as to slide between a first position in which the machine is configured to exert a torque in a first direction about an axis of rotation (10) and a second position in which the machine is configured to exert a torque in a second direction, the direction changing drawer (26) being mounted so as to slide along an axis (42) at a distance from the axis of rotation (10), the direction changing drawer extending:in a wall of the distributor (16); orin a wall of the distribution cover and outside the displacement selection drawer (35).

Provided is a design method for a self-compensation structure of a cam-lobe hydraulic motor plate distribution system, which comprises that follow steps: firstly, establishing a force balance equation, a pressure distribution equation and a flow balance equation for each balance chamber, setting a boundary condition, and setting an expected nominal clearance; selecting a fit clearance for simultaneous solutions, and obtaining a set of solutions of areas; taking a maximum value in this set of solutions as the median, and setting a set of area values in the optimization design; further solving changing curves of the nominal clearance and the total leakage of the distribution system with the rotation angle of the cylinder block, and calculating the average value of various curves after the operation is smooth, and designing the self-compensation structure based on selection of the optimal combination of the fit clearance and area.