Nonlinear characteristics of rubbing rotor–bearing system of locomotive excited by rotating speed of the traction motor

Abstract

The paper aims to study the nonlinear characteristics excited by rotating speed of the traction motor. Considering the rub-impact force, Hertzian contact force and unbalanced rotor, a typical of dynamic model of rotor-bearing system for locomotive is established, and Runge-Kutta method is adopted to solve the nonlinear response. Based on bifurcation diagrams, axis trajectory curves, phase plane portraits, Poincaré maps and amplitude spectrums, nonlinear characteristics of the system are analysed when rotating speed of the traction motor is changed. The simulation reveals complex dynamic behaviour of the system including periodic, multi-periodic and chaotic motion. The results will help us understand and control the nonlinear behaviour of the proposed traction system for railway locomotive in the future research.