A Study on Theoretical Flowrate of Gerotor Pump Using Chamber Areas

摘要

Gerotor oil pump supplies rotating elements with lubricating oil to prevent wear and to reduce frictional heat. Theoretical flowrate is needed to calculate volume efficiency of gerotor pump and irregularity, which mainly influences on pump noise. Therefore, accurate calculation of theoretical flowrate is crucial to predict performance of the gerotor pump. In this study, a new approach was proposed to calculate theoretical flowrate of the gerotor pump using chamber areas surrounded by coordinates of inner and outer rotors between contact points. Also, an automatic program applying the new methood was developed, based on numerical analysis program, Matlab, and theoretical flowrates of the gerotors with the various lobe shapes (circle, ellipse1-involute-ellipse2, 3-ellipse and 2- ellipse) for the six-speed auto transmission were calculated. To verify accuracy of the new method, theoretical flowrates calculated by chamber areas were compared to those obtained both from the vane length method and from the performance experiment.