机床电主轴动静压轴承性能的仿真和试验研究

Simulation and Experimental Research on Performance of Hybrid Bearings of Precision Machine Tool Electric Spindle

先进制造方式需要机床具有高速高精密的电主轴功能部件,选用动静压轴承可以提高车削加工中心电主轴的刚度和回转精度,因此选择动静压轴承作为主轴的支撑形式。轴承周向有4个浅腔形式油腔,以小孔节流形式恒压供油。建立润滑分析模型,分析轴承的承载力、最小膜厚和温升等静态性能指标。在卧式试验台上测试轴承的动态性能,结果表明:刚度随着转速的增加主要呈增大趋势,转速在3 000~6 000 r/min时刚度值比较稳定;水平方向和垂直方向的最大振幅分别为4.5、3.9μm。若要提高回转精度可对转子轴系进行优化,并做好动平衡及隔振。

In advanced manufacturing methods,electric spindle functional components with high speed and high precision are required in machine tools.In order to make the electric spindle of turning machining center have high stiffness and rotary precision at high speed,the hybrid bearing was chosen as the spindle support form.Bearing with four circumferential oil cavity structure selected,and orifice throttling constant pressure oil supply form was chosen.A lubrication analysis model was established to analyze the bearing capacity,minimum film thickness,temperature rise and other static performance indexes.The dynamic performance of the bearing was tested on a horizontal test bench.The test results show that the stiffness of the bearing increases with the increase of the speed,and the stiffness is relatively stable under the speed of 3 000~6 000 r/min;the maximum amplitudes in horizontal direction and vertical direction are 4.5 μm and 3.9 μm respectively.To improve the rotary precision,the rotor shafting system can be optimized,and dynamic balance and vibration isolation should be done well.