Research on the bearing dynamic modeling considering the combined friction-damping effect at the cage-guide ring interface and the motion-force coupling mechanism of the cage

To investigate the motion-force coupling mechanism of cylindrical roller bearing cages under different whirl modes, a dynamic model-based on the dynamic Reynolds equation and the short bearing assumption-for simulating the cage motion trajectory was established on the basis of existing modeling work. The combined friction-damping effect at the cage-guide ring interface is further considered. The capability of the proposed model to predict the motion states and principal motion characteristics of the cage was validated by comparing the simulation results with existing literature and experimental data. The average and the maximum relative error between simulated and experimental dominant frequency components were 8.91% and 19.26%, respectively, and the predicted cage whirl direction and guide clearance phase relationships were generally consistent with the experimental results. On this basis, the motion-force coupling mechanism of cages under three typical whirl modes was further investigated, and the results indicate that: In the stable whirl mode, the oil film force F co serves as the primary force sustaining the cage whirl, the frictional force F ct determines the whirl direction and the resultant collision force F cc induces interference. In the random whirl mode, the irregular whirl of the cage is predominantly induced by the resultant collision force F cc . In the local periodic whirl mode, the oil film force F co primarily contributes to the eccentric motion of the cage, whereas the resultant collision force F cc induces the tangential reciprocating motion of the cage.