A hydraulic radial piston device includes a housing, a pintle having a pintle shaft, a rotor mounted on the pintle shaft and defining a plurality of cylinders, and a plurality of pistons displaceable in the cylinders. The radial piston device further includes a piston ring that provides an interface for the pistons. The radial piston device includes various configurations for improving the performance and efficiency of the device.

A radial piston machine includes a housing, rotor, first braking member, and brake ring with a second braking member. The rotor is mounted in the housing to be rotatable relative to an axis of rotation, and has an end face facing in a direction of the axis of rotation. The first braking member is positioned on the end face. The housing has a body defining a ring-shaped extension relative to the axis of rotation. The brake ring is positioned to surround the extension and is configured to be movable in the direction of the axis of rotation so as to bring the second braking member into braking engagement with the first braking member. The brake ring is further configured to positively engage with an inner radial side of the extension to limit a twisting between the housing and brake ring.

The devices comprises a distributor (16) that presents distribution ducts opening out into a radial distribution face (16A), and a distributor-counterpart engaged in each other in such a manner that two main enclosures (18, 20) are provided between their opposite axially-extending faces. The device comprises a cylinder-capacity selector comprising two slides (24, 26) arranged after the other in a bore (22) of the element engaged in the other, to which are connected the main enclosures (18, 20) and at least some of the distribution ducts (30, 31). The slides are able to adopt at least three distinct configurations establishing different connections between the main ducts (18, 20) and the distribution ducts via the main enclosures, in order to be able to obtain at least three distinct operating cylinder capacities.

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).