Experimental Simulation of Piston Leakage in an Axial Piston Pump

A method used to introduce “artificial leakage” into an axial piston pump to simulate leakage from a worn piston is described in this paper. A pressure control servo valve with a very high frequency response was employed to divert flow from the pump outlet in a prescribed waveform directly to tank. The purpose was to simulate piston leakage from the high pressure discharge chamber to the pump case drain chamber as the “simulated worn piston” made contact with the high pressure chamber. The system and associated control algorithms mimiced the action of a single worn piston at various degrees of wear. The experimental results indicated that the experimental system could successfully introduce artificial leakage into the pump which was consistent with a unit with a “real” worn piston. Comparisons of the pressure ripples from an actual faulty pump (with one worn piston) and the artificial faulty pump (with one simulated worn piston) are presented.Copyright © 2005 by ASME