Roundness measuring system for small balls

小球圆度测量系统

• 批准号: 10650145
• 负责人: MIZUMOTO Hiroshi
• 金额: $ 2.18万
• 依托单位: Tottori University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650145/
• 关键词: Aerostatic bearing; Bearing; Hydrostatic bearing; Measuring instrument; Mechatronics; Rotary machinery; Roundness measurement; Precision machine

An aerostatic bearing with active inherent restrictors is developed for the main spindle of a roundness measuring system planned to measure small balls. The active inherent restrictor (abbreviated AIR) was invented by the head investigator, and incorporated into several aerostatic bearings and guideways for improving their performances. The AIR consists of a piezoelectric actuator having a through hole, one end of the hole is small enough to function as an orifice when the actuator is embedded in the bearing surface. When a sensor detects the change in the air gap on the bearing surface, a computer of the AIR-control system calculates the supply voltage for the piezoelectric actuator to change the pressure on the bearing surface, and to reduce the displacement and vibration of the main spindle. The major specification of the aerostatic bearing for the main spindle is as follows : the outer diameter is 140mm and the height is 86mm. There are eight AIRs on each radial and thrust bearing surface.Without using the active control system, the rotational accuracy of the main spindle is about 0.2mm. Active control using the AIR improves the rotational accuracy to be 20-30nm. The frequency response of the bearing with the AIR shows that the effect of the AIR on the dynamic stiffness of the bearing can be seen in the low frequency range (less than 20Hz). However, the measured rotational accuracy is not enough for the main spindle of the roundness measuring machine because the planned resolution of the roundness is 1nm. The main reason of the lack in the rotational accuracy is the geometrical error of the bearing surface on the spindle. Several efforts have been performed to improve the geometrical accuracy, however, the rotational accuracy of the main spindle can not be improved.

为圆度测量系统的主轴开发了一种带有主动固有限流器的空气静压轴承，该系统计划用于测量小球。主动固有限流器（缩写为AIR）由首席研究员发明，并结合到多个空气静压轴承和导轨中以提高其性能。 AIR 由具有通孔的压电致动器组成，该孔的一端足够小，当致动器嵌入轴承表面时，可以充当孔口。当传感器检测到轴承表面气隙的变化时，AIR-control系统的计算机计算出压电执行器的供电电压，以改变轴承表面上的压力，从而减少主轴的位移和振动。主轴空气静压轴承主要规格为：外径140mm，高度86mm。每个径向和推力轴承表面有8个AIR。在不使用主动控制系统的情况下，主轴的旋转精度约为0.2mm。使用AIR的主动控制将旋转精度提高到20-30nm。带有 AIR 的轴承的频率响应表明，在低频范围（小于 20Hz）可以看到 AIR 对轴承动态刚度的影响。但圆度测量机主轴的测量旋转精度还不够，因为规划的圆度分辨率为1nm。旋转精度不足的主要原因是主轴上轴承表面的几何误差。为了提高几何精度已经进行了多种努力，但是主轴的旋转精度却无法提高。