Dynamic Analysis of Rotor-Ball Bearing System of Air Conditioning Motor of Electric Vehicle

Abstract

Nowadays, electric vehicles (EV) present a promising solution to reduce greenhouse gas emissions. They are considered zero emission vehicles. Rotor bearing system is important part of air conditioning motor of EV. The aim of this research is to develop a numerical model to investigate the structural dynamic response of the rigid rotor supported on deep groove ball bearings. The numerical model considers rotor imbalance that varies with speed, as well as sources of nonlinearity such as Hertzian contact force, ball clearance and varying compliance vibration. This is very important on the design point of view. The 4th order Runge-Kutta numerical integration technique has been applied. The results are presented in form of time displacement response, frequency spectra, and Poincare map. The analysis demonstrates that the number of balls is one of the key factors affecting on the dynamic characteristics of rotor bearing system. The model can also be used as a tool for predicting nonlinear dynamic behavior of rotor system of air conditioning motor of electric vehicle under different operating conditions. Moreover, the study may contribute to a further understanding of the nonlinear dynamics of rotor bearing system.