摘要 |
Methods and apparatus are provided for lubricating a piston-to-shoe interface in a hydraulic motor or pump. Piston assemblies are installed in a housing that are each adapted to receive a reciprocating drive force and are each configured, in response thereto, to cyclically move between an intake direction and a discharge direction. Each piston assembly includes a piston and a piston shoe, and the piston, the piston shoe, or both have a plurality of pockets formed in a surface that defines a piston-to-shoe interface. When the pistons cyclically move, liquid is supplied to each piston-to-shoe interface to form a hydrostatic bearing at each piston-to-shoe interface. A portion of the liquid that is supplied to each piston-to-shoe interface is selectively supplied to and from one or more of the plurality of pockets. |