高速主轴不平衡振动行为分析与抑制策略

To suppress the unbalanced spatial vibration in a high-speed spindle system, a five-degree-of-freedom finite element model of the high-speed spindle was built and the comparison of the modal characteristic information of the spindle obtained by Matlab and Ansys was made. Simulation results indicate that the changing rules of the bending shapes and the peak values of the amplitude-frequency response are the same. Then, to further verify the validity of the proposed model, the experimental frequency response function of the high-speed spindle was obtained through modal test, and the results show that the difference between the measured first three-order critical frequency and the simulated result obtained by the dynamic model is 0.16%, 4.38%, and 5.95%, respectively, which means the proposed model can accurately describe the dynamic characteristics of the spindle. Based on this model, the spatial vibration characteristics at different nodes of the spindle under various unbalanced excitations were analyzed, and the influences of mode shapes and unbalanced excitations were summarized. Finally, an unbalanced vibration suppression strategy based on the model was proposed and the experimental analysis on a high-speed spindle system was performed at 9 000 r/min. Experimental results show that the strategy can identify the unbalanced vectors without trial weights, it only needs to collect the vibration information below the first-order critical speed, and the unbalanced vibration can be effectively suppressed after adding counter weights.