热误差是精密机床最主要的误差源之一.主轴是机床的关键部件,其热误差直接影响机床的加工精度.文章以某型号精密卧式加工中心主轴为对象,对其温度场和热变形进行了仿真分析.根据仿真结果发现主轴轴向热变形更严重,并结合机床结构确定温度传感器布置位置.在此基础上,对不同转速下主轴部分位置温度和轴向热误差进行现场测试.运用最小二乘法建立热误差补偿模型,直接结合机床FANUC数控系统实施主轴轴向热误差补偿.经实验验证,补偿后主轴轴向热误差减小了85％以上.%Thermal error is one of the most significant errors of the precision machine tool. The spindle is a primate part of the machine tool, and its thermal characteristics have great influence on the accuracy of the machine tool. The temperature field and thermal deformation of the spindle of a certain type of precision horizontal machining center were analyzed first. It was found that the axial thermal deformation was larger than the radial thermal deformation. And the optimal places of the temperature sensors were determined considering the structure of the machine tool. Then the temperature of some certain points on spindle and axial thermal deformation of spindle operating at different rate were measured. On basis of the experimental data, the thermal error compensation model was built by using least square method. The predicted thermal error based on the model was sent to the FANUC CNC system directly for thermal error compensation. The test results showed that the axial thermal error was reduced more than 85 percent.
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