基于有限元法的电主轴滚动轴承油气润滑热态特性分析.doc

基于有限元法的电主轴滚动轴承油气润滑热态特性分析 基于有限元法的电主轴滚动轴承油气润滑热态特性分析 摘要： 机床是机械制造业的主要生产工具 ,而主轴单元是高速切削机床的关键部件。因此 ,在高速加工中 , 电主轴的热态特性成为影响加工精度的一个主要因素 ,并直接限制电主轴转速的提高。由于电主轴以几万转甚至是十几万转运作时，电机的损耗发热和轴承的摩擦发热是不可避免的，由此而引起的热变形如果处理不当会严重的降低机床的加工精度。电机发热用冷却液冷却，我们主要研究轴承的摩擦发热。轴承的摩擦而产生的热量反映到实测的物理数据就是温度的升高。当采用油－气润滑后，摩擦减少，温升也随之降低，最后达到一个平衡温度。 目前对于电主轴的热态分析国内大多停留在物理试验上，本文是从理论上对其分析。本文以相关试验台为参照，建立有限元模型。对边界条件：不同主轴转速，不同的润滑油运动粘度，不同的预紧力进行有限元分析。从结果看，当主轴转速在两万转每分钟时，轴承温升平均在二十几度，三万转时平均温升为三十几度；粘度等级从 32＃～ 68＃，运动粘度的提高会导致温升增加；而轴向预紧力变化反映到结果上影响很小。 ? ? ? 关键词： 电主轴，滚动轴承，油气润滑，热态特性，有限元分析法 ? ? Abstract ： The machine tool is the main implements of the machine manufacturing, and the Motorized spindle unit is the key part of the high speed cutting machine tool .Therefore, in high speed process, the thermal characteristic of the Motorized spindle becomes a main factor that influence the accuracy of processes, and limit the rotate speed of the Motorized spindle to exaltation. Because when the Motorized spindle rotates with several ten thousand even several hundred thousand, the exhausts fever of electromotor and the friction of the bearings is ineluctable, for if not be handled properly ,it will lower the process accuracy of the machine tool seriously, and cause heat transform. The fever of electromotor can be cool off by liquid cooling, we main research the friction fever of the bearings. Because the calories of friction fever about the bearings reflect to measure, actually is the raising temperature, being to adopt the oil-air lubrication to make rub decrease, temperature rise also lowers immediately, and attaining an equilibrium temperature finally. Currently ,the thermal analysis of the motorized spindle mostly stays around the physics experiment in the home, this text analysis it at theories. This text is according to the correlation experiment pedestal, build up a model. To the boundary condition: The different principal axis rotating speed, the different lubricant sport glues degree, different beforehand tight force to do an analys