Noise and vibration of a variable displacement vane oil pump for passenger car

Abstract

This study analyses the noise and vibration characteristics of a variable displacement vane oil pump for a passenger car. Design guide lines of the vane oil pump are proposed to reduce the noise and vibration after noise and vibration sources of the pump are identified and important design factors are selected. In order to identify the noise and vibration sources, two types of measurement experiments are performed: one is an experiment with a running engine and the other is an experiment using a test machine. It is found that the pump noise is caused by vibration and some specific harmonics of vane rotation that have critical effects on vibration generation. Based on experiment data, a dynamic model for the oil pump is established, which includes cam and rotor motions, as well as the excitation moment due to oil pressure. Furthermore, important design factors are selected which reduce vibration while maintaining oil delivery. Finally, some design changes are proposed to reduce the noise and vibration with the required oil delivery.