Nonlinear Dynamics of an Unbalanced Rotor Bearing System of Electric Vehicle with Radial Internal Clearance

In recent years with continuing demands for increased performance, most of electric motors are now being designed for operation at high speed, a trend which has resulted in increased mechanical vibration and noise problems. Dynamic analysis of rotor system need to be done to predict vibration behavior in rotating structures to improve the design and decrease the possibility of failure. For this work, nonlinear dynamics of rotor system will be considered with the effect of internal radial clearance. The aim of this work is to develop a numerical model for investigation of the influence of nonlinear source on the dynamic characteristic of rotor ball bearing system. The numerical integration technique 4th order Runge-Kutta method is used to solve the system of nonlinear differential equations iteratively. The result presents here have been achieve from huge number of numerical integrations; mainly presented in form of time displacement response, frequency spectra, and Poincare map. Analyses have been carried out to observe that the characteristic of the dynamic behavior of the system is sensitive to small variation of the system parameters and the effect of radial internal clearance on the dynamic characteristics of a rotor-ball bearing system.