Research on of the nonlinear resonance response of the high-speed spindle system supported by preloaded ball bearings

Abstract This paper presents a comprehensive study on the nonlinear resonance response of the high-speed spindle system supported by preloaded ball bearings. Firstly, the nonlinear stiffness characteristic of the ball bearing-rotor system is studied based on the analysis of the contact nonlinearity and geometric nonlinearity generated by supporting ball bearings. Secondly, a simplified rigid rotor system is built to discuss its nonlinear "soft-spring" and "hard-spring" stiffness effects across varying speeds and external loads. Thirdly, the nonlinear resonance response mechanism of the spindle system near its 1st -order equivalent linear resonance frequency is predicted, and the effect of "soft-spring" and "hard-spring" stiffness characteristics on its resonance response mechanism is detailed analyzed. Finally, a hybrid-supported experimental spindle system is built to verify the theoretical prediction results on the nonlinear resonance response of the preloaded ball bearing-rotor system. The results show that the resonance response curves of the rotor system exhibit the leftward "bending" characteristic corresponding to the "soft spring" stiffness effect under the low speed and light load ranges, while exhibit the rightward "bending" characteristic corresponding to the "hard spring" stiffness effect under the high speed and heavy load ranges.