应用有限元法建立偏置转子的计算模型,采用考虑轴承Hertzian接触力和内间隙等非线性因素的二自由度滚动轴承模型,建立了滚动轴承-偏置转子系统的非线性动力学模型.通过数值仿真和实验研究分析了转子系统的非线性动力特性.实验数据和有限元模型计算结果是一致的,证实了所建立滚动轴承-转子系统非线性模型的合理性.发现由于滚动轴承非线性因素的影响,当转速达到系统共振转速的两倍附近时,激起了系统亚谐共振.
The discrete model of offset disk rotor is established with the finite element method. A two-de-gree-of-freedom model of ball bearing, including effect of Hertzian contact force, bearing internal clearance, is employed to investigate the dynamic characteristics of the rotor system supported by ball bearings. The ball bearings-offset disk rotor system is simulated according to the discrete rotor model and the ball bearing model. The nonlinear dynamic performance is evaluated numerically and experimentlly. All of the predicted results coincide well with the experimental data to validate the proposed model. It is revealed that the resonance frequency is provoked and the subharmonic resonance occurs due to the nonlinearity of ball bearings as the speed approaches to twice synchroresonance frequency.