This invention relates to a piston for reciprocating and simultaneously rotating through a predetermined length of movement within a piston bore having a piston bore surface, and a method for reducing wear on a piston bore surface operatively associated with a piston which is subject to cocking forces. The piston includes a means on its extreme portion for providing continuous, tangential cooperation with the piston bore surface within the predetermined length of piston movement to reduce wear on the piston bore surface.
A piston for use in the cylinder block of a hydraulic power unit. The piston has an elongated cylindrical body with one end configured to connect with a slipper element. The second end of the piston is open with an annular cavity in the piston body defining an elongated stem extending from the head end of the piston and slightly protruding through the open end. The stem is concentrically located within the longitudinal axis of the annular cavity and has an elongated fluid conduit that extends longitudinally through the stem and completely through the piston. The fluid conduit traverses the piston body along the center axis, providing a path for pressurized fluid. The piston is composed of a unitary cast construction.
