小型高速精密气浮气动主轴的研制
Developing a Small High-speed Air-driven Pneumatic Spindle

针对微结构的超精密磨削要求,设计了一种涡轮驱动的小型气浮主轴。采用了涡轮叶片作为动力结构部分,由压力气体驱动,带动主轴高速旋转;同时也采用了空气静压轴承作为支撑;建立了气动涡轮的设计模型,分析了气体静压支承轴承的结构参数,仿真研究了各设计参数对轴承承载力的影响,得出了最佳的设计尺寸和主轴工作参数,对涡轮与转轴组成的整体转子进行了模态分析,计算出了主轴的临界转速,研究了主轴的加工工艺。试验结果表明:该设计合理,达到了设计要求。
This paper designs an air turbine-driven spindle which is supported by air bearings for ultra-precision machining of a microstructure. An air turbine is used as the micro-structure powered with high-pressure air, and three air bearings are used as the supporting device. The design model of air turbine is established, and the structural parameters of air bearings are analyzed. The effects of various design parameters on the capacity of air bearing were simulated, and the optimal dimensions and working parameters were obtained. Moreover, the natural frequency of the turbine and its rotor including the shaft is studied, thus obtaining the critical rotational speed. Finally the paper studies the machining process of the air turbine-driven spindle and conducts experiments on the spindle. The experimental results show that our design method is reasonable and meets the design requirements