Fault dynamic model of high-speed rolling bearing by a compound displacement excitation function considering the effect of defect roughness

Most of bearing fault dynamic models use simple displacement excitation functions to characterize the fault excitations from defects, and do not consider the influence of high-speed, dynamic radial clearance and transmission path, which brings the simulation signal a big gap with the measured signal. To solve these issues, this paper proposes a compound displacement excitation function by considering the influence of defect roughness, then constructs a new fault dynamic model of high-speed angular contact ball bearing (ACBB) by using the proposed displacement excitation function and introducing the effects of high-speed, dynamic radial clearance and transmission path. The proposed ACBB fault dynamic model is numerically solved for obtaining the dynamic responses under different fault sizes and speeds, then their characteristics in time and frequency domains are analyzed. The comparative results indicate that the simulation signals generated by the proposed model are closer to the measured signals, compared with those obtained by the typical bearing fault dynamic models. Finally, the correctness and superiority of the proposed model are verified by the experiments on faulty high-speed ACBBs.