Rotation-preventing device for an orbiting piston-type fluid displacement

Abstract

A rotation-preventing/thrust-bearing device for use in an orbiting-member fluid displacement apparatus is disclosed. The rotation-preventing/thrust-bearing device includes a discrete fixed portion, a discrete orbital portion and bearing elements. The fixed portion includes a fixed race and ring placed in a groove in an inner surface of the housing. The fixed race and ring are attached to the housing by pins, and the inner peripheral edge of the groove is caulked to the fixed ring. The orbital portion includes an orbital race and ring placed in a groove in an end plate of the orbiting member. The orbital race and ring are attached to the end plate of the orbiting member by pins, and the outer peripheral edge of the groove in the end plate is caulked to the orbital ring. A plurality of pockets are formed axially in the rings toward the respective races. The pockets of the rings face one another in generally aligned pairs. A bearing element is received in each aligned pair of pockets to prevent the rotation of the orbiting member by the bearing elements interacting with the orbital and fixed rings and to carry the axial thrust load from the orbiting member. The rotation of each ring, which is caused by protation-preventing operation, is prevented by both the pins and the caulked connection.