Development of High-Performance Spindle for Micro Factory for Machining Ultra-Precision Meso-Scale Parts

本课题旨在研制一种适用于中尺度精密零件加工的超精密机床系统用水驱动主轴。本项目的主要成果如下：1.研制了水驱动主轴。(1)新设计制造了水驱动主轴。设计了水静压轴承，通过优化轴承限位器，使轴承具有较高的刚度。(2)对研制的主轴回转精度进行了测试。实验表明，主轴跳动小于60 nm。(3)研究了压力脉动对回转精度的影响。主轴液压系统采用高效蓄能器。(4)研制了包括旋转式流量控制阀和控制软件在内的控制系统，使液压主轴在负载变化的情况下都能保持转速。2.研制了精密工作台。测量了工作台直线运动的直线度和定位精度分别为50 nm和0.3μm。(2)制作了由水驱动主轴和空气工作台组成的小型超精密机床系统。3.通过金刚石调谐评价主轴性能。结果表明，加工后的表面具有光学质量。表面粗糙度通常为30 nm。

This research project has been conducted in order to develop a water drive spindle for ultra-precision machine system that is suitable for machining meso-scale precise parts. The crucial results of the project are the followings :1.Developed water drive spindle(1)Water drive spindle was newly designed and fabricated. Water hydrostatic bearings were designed so that high stiffness of the bearing can be obtained by optimizing the bearing restrictors.(2)Rotational accuracy of the developed spindle was measured. The experiments show that the spindle runnout is less than 60nm.(3)It is shown that the pressure pulsation affects rotational accuracy. An effective accumulator will be used to the water power system for the spindle.(4)Control system, including rotary-type flow control valve and control software has been developed so that speed of the water drive spindle can be maintained regardless of load change.2.Developed precision stage(1)A precision air stage has been developed. Straightness and positioning accuracy of linear motion of the stage were measured as 50nm and 0.3μm, respectively.(2)Small ultra-precision machine system, consisting of the water drive spindle and the air stage, has been fabricated.3.Evaluation of spindle performance by diamond tuningDiamond turning tests were performed using the developed small ultra-precision machine. The results show that the machined surfaces have optical quality surface. The surface roughness was typically 30nm.