IMPROVEMENTS IN AND RELATING TO HYDRAULIC PUMPS AND MOTORS

摘要

A piston assembly for an axial displacement pump or motor comprises a piston (15) having at one end a ball shaped piston foot (16) and a slipper (41). The rear end of which defines a piston ball seat (42) in which the ball shaped piston foot (16) is received. A slipper pad (44) defines an annular, centrally located recess or pocket at the front end of the slipper (41). The slipper pad (44) comprises an annular ring (44) of polymer material.