Vibration characteristics analysis of rolling bearing rotor system considering radial clearance and outer raceway defect

Because of the radial clearance, the radial stiffness of rolling bearing will show obvious time-varying characteristics, which may cause a certain vibration. The small defects on the raceway of the rolling bearing maybe caused by the vibration under the poor lubrication conditions. A dynamic model of rolling bearing rotor system considering the radial clearance and outer raceway defect is established in this paper. The time-varying stiffness of rolling bearing is fitted by 8-order Fourier series and substituted into the dynamic model. The vibration response of rotor system is obtained to analyze the fault characteristic frequency of rolling bearing. The vibration test of rolling bearing rotor system is carried out, and the fault characteristic frequency of the test bearing is identified by analyzing the frequency spectrum of the obtained vibration signal. The test results are in good agreement with the theoretical values, which verifies the correctness of the dynamic model.