Dynamic characteristics analysis of wind turbine gear system considering bearing defects

Under the working conditions of high speed and heavy load of large wind turbines, the load changes caused by wind are easy to cause bearing defects, and then affect the transmission efficiency and stability of gear system. This paper takes the angular contact ball bearing of wind turbine gear system as the research object, establishes the dynamic model of the angular contact ball bearing considering defects, and analyzes the contact force response of the defective bearing. On this basis, the influence of bearing defects on the dynamic characteristics of the gear system is studied and the dynamic response of the defective bearing to the gear system under cyclic load is analyzed. The results show that: when the bearing defects occur, the bearing capacity will be reduced or lost when the rolling element passes through the defect position, the effective stiffness of the bearing assembly will change due to load redistribution, and the bearing failure will make the system tend to be unstable, but the influence on the system motion state form is small within a certain range. Under the action of cyclic load, bearing defects can make the system tend to be unstable, but they have little influence on the motion state of the system within a certain range.