Patent ID: 7322377

Claim:
A hydraulic accumulator, comprising: an accumulator housing extending along a longitudinal axis and having a gas side, a fluid side and a side wall; a piston being movable in said housing along said longitudinal axis, separating said gas side and said fluid side, and having an annular groove on a periphery thereof and a reduced outside diameter section extending from said annular groove at an end of said piston adjacent said fluid side; first and second guide elements on said periphery of said piston interacting with said side wall of said housing and located adjacent said gas side and said fluid side, respectively, said second guide element being a guide belt with a dirt stripper lip extending at least approximately to an end of said piston and with a plain compression ring sitting in said annular groove, said dirt stripper lip lengthening a radially outside surface of said guide belt on one axial end thereof in an axial direction, tapering toward a free end thereof at a 10° angle relative to said longitudinal axis and extending over said reduced outside diameter section, said compression ring being rectangular in transverse cross-section, said dirt stripper lip having a root adjacent said compression ring with a thickness less than one-half a radial thickness of said compression ring; at least one sealing element offset in an axial direction on said periphery of said piston from said gas side and being spaced from and between said guide elements; a pressure equalization channel opening on said periphery of said piston between said second guide element and said sealing element, opening on an axial end of said piston on said fluid side, and providing fluid communication therebetween; and a device in said equalization channel reducing a cross-sectional area thereof.