Abstract: There is a fluid rotary machine having radial pistons and a shaft with an eccentric cam having a rotational movement relative to the housing. The cam mounts a ring on the exterior thereof and the pistons abut against the exterior surface of the ring with each piston mounted for sliding movement in the interior of the cylinder. The ring is associated with the distribution of the fluid of the machine to the pistons and cylinders. Means are provided to immobilize the ring against rotation relative to the housing and subjugate the ring to an essentially circular translation movement relative to the rotational movement of the eccentric cam on which the ring is mounted, and is characterized by the fact that the means for maintaining the ring in such a position comprises a plurality of elastic members connecting predetermined points of the ring to anchor points unassociated with the ring.

Abstract: The hydraulic motor has a shaft rotatably mounted in a housing and mounting an eccentric to which is journaled an annular ring. A plurality of radial pistons are adapted for sliding movement within spherical members having cylindrical bores for receiving the radial pistons. Each of the spherical members is adapted for oscillating movement between an annular abutment and a spring-mounted annular ring-type valve seat.The ring acts as a distributor sleeve or and as a conduit for fluid passing to and from the cylinders and a planar distributor.The hydraulic motor can be used either as a pump or a motor at low or high speeds and under high pressures and is reversible.