MOTION OF PISTONS IN PISTON-TYPE HYDRAULIC MACHINES - 3. EXPONENTIAL FUNCTION-TYPE PISTON.

Abstract

To stabilize the motion of pistons, it is possible to use such a piston that the film thickness between the cylinder and the piston varies exponentially with the longitudinal position along the piston. For piston-type hydraulic pumps and motors the numerical results indicate that in such a piston in which the film is thicker on the high pressure side, both stabilization of the motion and creation of film in the clearance are expectable. It is shown that the load capacity increases by expansion of cylinder due to pressure, while it reduces by projection of pistons out of a cylinder block. The leakage flow rate in the clearance and the frictional force acting on pistons are also shown.