Analysis of Pressure Pulsation and Vibration in Variable Displacement Vane Pump for Power Steering System(Fluids Engineering)

Abstract

A variable displacement pump is a high-efficient pump for hydraulic power steering systems. In order to develop a quiet variable displacement vane pump which leads to lower vehicle interior noise, we need to reduce pressure pulsation and vibration of the pump. So, we have developed a new simulation method for predicting pressure pulsation and vibration caused by a variable displacement pump. This simulation method combines hydraulic simulation and vibration simulation to predict vibration in the design phase. To improve accuracy of the hydraulic simulation, the deformation of the pump shaft was modeled. Moreover, method of characteristics using block diagram was used to calculate pressure pulsation of rubber-made pump outlet hose. This hydraulic simulation results were used as excitation force acting on the pump shaft in vibration simulation. As a result, hydraulic simulation predicted pressure pulsation of 11th order which comes from the number of vanes and its harmonics of the pump revolution accurately. The differences of predicted and measured results were within 0.1dB at 1500min^<-1>, 9MPa. And vibration simulation using the results of hydraulic simulation predicted vibration of 11th and 22nd order of the pump revolution that agreed well with experimental results.