Fluid rotary machine

Claim 1

A fluid rotary machine having radial pistons and a shaft with an eccentric cam having a rotational movement relative to the housing, the cam mounting a ring on the exterior thereof and the pistons abutting against the exterior surface of the ring with each piston mounted for sliding movement in the interior of a cylinder, the ring being associated with the distribution of the fluid of the machine to the pistons and cylinders, means immobilizing the ring against rotation relative to the housing and subjugating the ring to an essentially circular translation movement relative to the rotational movement of the eccentric cam on which the ring is mounted, 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, these elastic members being sufficiently strong to oppose the tendency of the ring to rotate with the cam, but on the other hand, having sufficient elasticity to be adaptable to different eccentricities of the cam when the actual displacement of the machine is being changed, said elastic members being such that their flexion is only a fraction of the value of the eccentricity of the cam, characterized by the fact that, between each spring anchored to the housing and the ring, there is provided a rotary lever having asymmetric arms and the fulcrum of which is fixed relative to the housing, one of the arms being connected to the spring and the other being slidably connected to the pivot axis of the ring.