The machine comprises distribution ducts connected to respective ones of first, second, and third enclosures (40, 42, 44), and a cylinder-capacity selector (21) suitable for being caused to take up a large cylinder capacity configuration in which the second enclosure (42) is connected to one of the main ducts (2), while the first and third enclosures (40, 44) are connected to the other main duct (1), and a small cylinder capacity configuration in which the second and third enclosures (42, 44) are connected to said one of the main ducts (2), while the first enclosure is connected to the other main duct (1). The machine further comprises a safety valve (150) having at least a first port (56) connected to said one of the main ducts (2), and a second port (58) connected to the third enclosure (44). Said safety valve is suitable, when the cylinder-capacity selector (21) is caused to go into the large cylinder capacity, for being caused to go into a first configuration that isolates the first and second ports (56, 58) from each other, and, when the cylinder-capacity selector is caused to go into its small cylinder capacity, for being caused to go into a second configuration that interconnects the first and second ports (56, 58).

An apparatus can include a housing, a plunger configured to reciprocate along an axis within the housing, and an internal fluid chamber disposed in the housing. A valve, having a valve base and a deformable seal, can also be included in the apparatus. The apparatus can further include a seat having an aperture therein. The valve is configured to move into and out of contact with the seat when the plunger reciprocates within the housing, based upon a fluid pressure in the internal flow chamber. In addition, an outer diameter of the deformable seal of the valve is less than an outer diameter of the seat.

Pump unit (10) comprising an electrically driven hydraulic pump (4) for pressurising a hydraulic actuating system. The pump unit (10) comprises a hydraulic pump (4) in pump chamber (110) of a pump housing (11). The pump (4) is driven by an electric motor (3) which includes a motor rotor body (310) and an assembly of field coils (32) and magnets (33). A clearance (C) is provided around the motor rotor body (310) which is diverging in the axial direction from a small to a large diameter, such that a rotation of the motor rotor body (310) forces hydraulic fluid to flow towards the larger diameter. The fluid outlet (122) at the larger diameter of the clearance allows an exit of the hydraulic fluid, such that a fluid flow is generated which reduces hydraulic friction inside the pump unit to render an increase in pump capacity.

A hydrostatic rotating machine includes an internal element and an external element that revolve with respect to one another about an axis of rotation, a cylinder block, and a hydraulic distributor. The hydraulic distributor includes an insertion section extending axially between a section of lesser diameter and a section of greater diameter, with a first synchronization surface, and fluid distribution ducts which each have an end segment opening transversely at the first synchronization surface, and obliquely with respect to the axis of rotation. The cylinder block includes a reception section complementing the insertion section of the hydraulic distributor, and fluid diffusion ducts which each have an end segment opening transversely at the second synchronization surface, and obliquely with respect to the axis of rotation.

A radial piston pump comprising a rotor mounted for rotation on a pintle. The rotor comprises a plurality of piston chambers, a piston being mounted in each of said chambers for reciprocal movement. The pump comprises at least one auxiliary flow path which connects another component of the pump to the piston chambers. The pintle comprises a plurality of flow galleries comprising at least one supply flow gallery forming part of a supply flow path, at least one exit flow gallery forming part of an exit flow path and at least one auxiliary flow gallery forming part of the auxiliary flow path.

A radial piston pump comprising a rotor mounted for rotation on a pintle. The rotor comprises a plurality of piston chambers, a piston being mounted in each of said chambers for reciprocal movement. The pump comprises at least one auxiliary flow path which connects another component of the pump to the piston chambers. The pintle comprises a plurality of flow galleries comprising at least one supply flow gallery forming part of a supply flow path, at least one exit flow gallery forming part of an exit flow path and at least one auxiliary flow gallery forming part of the auxiliary flow path.