The structure of normal rolling bearing is analyzed. There is a certain gap between the moving elements. The rolling element bears a certain load in the raceway between the inner ring and the outer ring to make a revolution. The imbalance between the excitation generated by gear engagement and shaft rotation results in the different number of loads borne by the bearing rolling element in different positions, resulting in the fluctuation of bearing stiffness and vibration In the process of contact between body and raceway, there will be elastic deformation and vibration under periodic excitation. The signals generated by these vibrations are random. In addition, the manufacturing error of the bearing will also cause vibration, such as the surface waviness of the moving parts and the size of the rolling element is uneven; the assembly error of the bearing will also cause vibration due to eccentricity; the external factors such as the inner ring and the shaft interference fit rotate together, and the shaft bending imbalance will also cause vibration due to the movement deviation of the bearing.
When the bearing failure occurs, the failure vibration will be intensified for the wear type failure, which is still irregular. As for the uneven faults on the surface of the moving elements caused by pitting, peeling, gluing and other reasons, when the moving elements pass through the fault points, they will produce impact and cause vibration. Because each moving element moves in a certain period, this kind of fault has a certain regularity. When the periodic vibration develops to a certain extent, it may arouse the natural frequency of the bearing elements Frequency and resonance.
First of all, the types and causes of several typical faults ofare discussed. Then, through the analysis of the physical model of gear mesh, the two most important factors affecting gear vibration are obtained: mesh stiffness and transmission error. Finally, the vibration mechanism of rolling bearing is analyzed.