Abstract: A new rotor-ball bearing-stator coupling dynamics model is established. In the model, the rotor mass unbalance and looseness of bearing house faults are included, and the nonlinear factors of ball bearing are considered such as the clearance of bearing, nonlinear Hertzian contract force between balls and races, and the varying compliance vibration because of periodical variety contact position between balls and races. The numerical integral method is employed to obtain system’s responses, and the vibration amplitude-rotating speed curve, bifurcation plot, phase plane plot, frequency spectra and Poincaré map are used to analyze bifurcation and chaos motion, and the effects of rotating speed, bearing house mass, rotor eccentricity, stiffness between bearing house and stator and stiffness between stator and foundation on system dynamic responses are analyzed, and the non-linear dynamic response characteristics of rotor-ball bearing-stator system under unbalance and looseness coupling faults are obtained.

Key words: Ball bearing, Looseness of bearing house, Multi-faults coupling, Rotor, Stator, Unbalance