Design, Modeling and Simulation of Gearing for Improving Gerotor Pump Performance

Abstract

Gerotor pumps are a special type of gear pumps with internal trochoidal gearing. Due to their compact design and simple structure, they are characterized by high reliability and low cost. They are represented in many applications, mostly in the automotive industry. Increasingly stringent environmental regulations require automotive manufacturers to improve vehicle design by increasing the efficiency of their components, including the gerotor pump. This paper presents a procedure for determining the optimal combination of trochoidal gearing design parameters, in order to improve the performance of a gerotor pump. Gerotor performance is affected by sliding velocity, volume efficiency and contact stress. An appropriate mathematical model was developed in order to analyze variation effect of gear design parameters related to value of the pump functional characteristics. In order to reduce the maximum contact stresses, forces and moments’ analysis was performed by analytical and numerical method. Through consideration of the gear tooth profile with technological gaps, their impact on the volume losses and gear ratio of the pump was identified. The verification of the developed models was carried out through the realization of physical gear pairs and performing of a laboratory experiments with simulation of pump operating conditions. These results establish valuable guidelines for constructors to design more efficient construction solutions of the gerotor pumps.