超高速空气静压轴承电主轴损耗及热特性分析

Research on Loss and Thermal Characteristics of Ultra-high Speed Aerostatic Bearing Spindle

电主轴作为高度集成的机电一体化产品,相对于传统的机床主轴,其将主轴电机集成内置到主轴内部,具有结构紧凑、低惯性、高转速、低噪声、快速响应等优点,但由于电机集成于主轴内部,运转时产生的大量热量,会引起电主轴温度快速升高,使电主轴的热态特性和动态特性变差,进而影响电主轴的正常加工甚至出现运转过程中卡死。为定量计算整机的损耗及发热变形情况以解决此问题,通过建立超高速空气轴承电主轴热特性分析模型,采用解析法与有限元仿真相结合的方法,求解电主轴轴芯空气摩擦损耗、电机损耗,获得了电主轴温升等热态特性参数,并通过试验验证分析模型和方法的准确性,研究模型中轴芯空气摩擦损耗理论计算数值与实验数值偏差在2%以内,为电主轴设计提供了理论依据。

Electric spindle is a highly integrated mechatronics product. Compared with the traditional machine tool spindle, it integrates the spindle motor into the spindle, which has the advantages of compact structure, low inertia, high speed, low noise, fast response, etc. However,because the motor is integrated into the electric spindle, a lot of heat generated during operation will cause the temperature of the electric spindle to rise rapidly. The thermal and dynamic characteristics of the electric spindle become worse, and then affect the normal processing of the electric spindle and even appear stuck during operation. In order to solve this problem by quantitatively calculating the loss and heating deformation of the whole spindle, the thermal characteristics analysis model of ultra-high speed air bearing electric spindle was established,and the air friction loss and motor loss of the spindle by combining analytical method and finite element simulation was solved, and the thermal characteristics parameters of the electric spindle such as temperature rise was obtained. The accuracy of the analysis model and method was verified by experiments. The deviation between the theoretical calculation value and the experimental value of the rotor friction loss of the model in the study is within 2%, which provides a theoretical basis for the design of electric spindle.