ELONGATED SLIDING SHOE FOR REVOLVING CYLINDERS OF HYDRAULIC POSITIVE-DISPLACEMENT PUMPS AND MOTORS Russian patent published in 2001 - IPC

FIELD: hydraulic machinery engineering; axial-flow piston-type positive-displacement units. SUBSTANCE: cylinder block for hydraulic positive-displacement drive has rotatable housing for pistons with many bores located in housing over circumference. Piston member is slidably received by each bore. Each piston member has outer end which extends from bore. Recess or seat has rounded-off crown portion in outer end of each piston. Sliding shoe of piston having bow-shaped base (sphere) is rotatably mounted in seat. Arm passes in outer direction from sphere and has flat surface passing laterally on other end. Flat surface slidably gets in contact with wobbler having flat control surface. Distance L between center of sphere and flat surface exceeds diameter D of piston member. EFFECT: considerable reduction of pressure exerted on surface of piston between cylinder pistons and bores for pistons; enhanced efficiency of torque of machine driven by proposed drive. 6 cl, 3 dwg