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.
A gerotor is suitable for miniature manufacturing because it has high discharge per 1 cycle and a simple structure, while also being widely used for lubrication oil of engines and as a hydraulic source of automatic transmission. In the automobile industry, improvements in fuel efficiency and noise reduction have recently come to the fore. It has also been necessary to continuously improve the flow rate and noise of internal gear pumps for better fuel efficiency through optimal gerotor and port shape design. In this study, to develop an optimal gerotor with a new lobe shape, 2-ellipses-combined, the equation of the lobe shape was derived, and CFD analysis results were compared for 2-ellipses with those of the previous gerotors (3-ellipses and ellipse1-involuteellipse2). A performance test for the oil pump with the optimal rotor (2-ellipses) was carried out and showed good agreement with the results obtained from CFD analysis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.