卧式五轴数控机床电主轴的动态特性分析及振动抑制优化

Dynamic characteristics analysis and vibration suppression optimization of motorized spindle of horizontal five-axis CNC machine tool

针对某卧式五轴数控加工中心电主轴动态特性较差、测试过程中振动量大的问题,对其建立动力学模型,利用Ansys Workbench对其进行模态分析,解得固有频率及模态振型。基于仿真结果及电主轴结构原理,诊断为电主轴后端悬伸量较大,外部连接法兰与主轴后轴承盖及冷却水套间隙量较大,导致机床固有频率低,动态特性差。针对上述原因对电主轴后端悬伸部增加辅助支撑优化设计,进行模态仿真分析,通过优化前后固有频率及临界转速数据对比验证其可行性。将优化设计应用于实际,并对电主轴进行振动测试,试验表明:电主轴振动量大幅减小,优化设计合理。研究结果为卧式五轴数控机床电主轴系统动态特性的改善,提供了优化思路和设计方法。

Aiming at the problem that the dynamic characteristics of the motorized spindle of a horizontal five-axis CNC machining center are poor and the vibration amount is large during the test process,the dynamic model is established,and the modal analysis is carried out by using ANSYS Workbench to obtain the natural frequency and modal shape.Based on the simulation results and the structural principle of the motorized spindle,it is diagnosed that the rear end of the motorized spindle has a large amount of overhang,and the gap between the external connecting flange and the rear bearing cover of the spindle and the cooling water jacket is large,resulting in low natural frequency and poor dynamic characteristics of the machine tool.For the above reasons,the auxiliary support optimization design is added to the rear end of the motorized spindle,and the modal simulation analysis is carried out.The feasibility is verified by comparing the natural frequency and critical speed data before and after optimization.The optimization design is applied to practice,and the vibration test of the motorized spindle is carried out.The test shows that the vibration of the motorized spindle is greatly reduced,and the optimization design is reasonable.The research results provide optimization ideas and design methods for improving the dynamic characteristics of the motorized spindle system of the horizontal five-axis CNC machine tool.