Ring dampener for rotary fluid pressure device

A rotary fluid pressure device for use as a pump or motor comprising:

• A. a housing member defining a cavity and a pair of confronting axially spaced surfaces;
• B. a rotor located within the cavity and having a plurality of circumferentially spaced radially extending openings;
• C. an element movable within each of said openings;
• D. a chamber partially defined by each element and adjustable in size with movement of said element;
• E. means supporting the rotor relative to the housing member for rotation about an axis;
• F. a confining member disposed between the surfaces, encircling the rotor, engaging the elements, and being movable relative to an axis to adjust the maximum extent of movement in one direction of the elements within the openinga;
• and
• G. means for reducing the vibration of the confining member during rotation of the rotor, said means including
• (1) a shoe supported by one of the members for axial movement into engagement with the other member;
• and
• (2) means for exerting a force on the shoe in an axial direction to move the shoe into engagement with the other member, the magnitude of the exerted force on the shoe being proportional to the magnitude of the pressure of the fluid within certain of said chambers.