Nonlinear vibration characteristics of a rotor bearing system with irregular raceway defect

The precise characterization of the interaction between rolling elements and defect areas significantly influences the vibrational response of faulty bearing dynamic models. This research initially examines the geometric correlation between the characteristics of defect edges and the dimensions of the defects, deriving the time-varying displacement excitation function for inner and outer race spalling faults in ball bearings. Next, an irregular surface model of bearing raceway defects under natural degradation conditions was simulated, and a dynamic model of these defects was established by coupling time-varying displacement excitation functions, while considering edge expansion and morphological features. The influence of the local morphology of the defect on the vibration characteristics of the system was investigated. The contact forms between the rolling elements and the defect region were classified into different types based on whether the rolling elements made contact with the bottom of the defect area. The vibration response characteristics of the rolling elements under varying fault sizes were analyzed. The results indicate that as the defect size increases, the amplitude of acceleration rises, the pulse interval lengthens, and the pulse characteristics become more pronounced. The irregular raceway defect model effectively characterizes high-frequency vibrations associated with bearing faults, contributing to a deeper understanding of the high-frequency noise signals generated by such faults in bearings.