Nonlinear Dynamic Response Analysis of Rotor-Ball Bearing-Stator Coupling System Including Unbalance-Rubbing Coupling Faults

Abstract

In this paper, a new rotor-ball bearing-stator coupling system dynamic model is established. In the model, the rotor mass unbalance and rubbing faults are included, and the nonlinear factors of ball bearing such as the clearance of bearing, nonlinear Hertzian contract force between balls and races, and the varying compliance vibration coming from the periodical variety of contact positions between balls and races are modeled. The numerical integral method is employed to obtain system’s responses, and the vibration amplitude-rotating speed curve, bifurcation plot, phase plane plot, shaft centre orbits, frequency spectrum and Poincare´ map are used to carry out the analysis of bifurcation and chaos motion, and the effects of rotational speed, rubbing stiffness, rotor eccentricity, bearing house-stator stiffness, and stator-foundation stiffness on dynamic responses are analyzed, and the non-linear dynamic characteristics of rotor-ball bearing-stator system under unbalance and rubbing coupling faults are discovered.