Design and CFD analysis of gerotor with multiple profiles (ellipse–involute–ellipse type and 3-ellipses type) using rotation and translation algorithm

Abstract

Gerotor is a key component used in internal gear pumps of vehicles, and as the technology of sintering process is highly advanced, the gerotor has advantages for manufacturing complex profiles and obtaining durability and minimization. But internal gear pumps have been continuously required to improve flow rate and noise for fuel efficiency. The existing gerotors with multiple profiles have been designed by only translation algorithm, which is limited to improve the performances. In this study, a new automated design and multiple calculation programs using rotation and translation algorithm were developed for improving the performances of multiple profiles, and two types of combined multiple profiles (ellipse 1-involute-ellipse 2 type and 3-ellipses type) were generated. The performances (flow rate, irregularity, specific sliding and pressure angle) of the profiles were calculated by using theoretical analysis, and optimal designs of the two types were carried out on the basis of analysis results. Also, internal flow characteristics in the optimized gerotor generated were analyzed by using commercial CFD (computational fluid dynamics) code, ANSYS-CFX.