为了克服现有技术存在的不足，实现光学测量装置在轴孔内的高精度测量，提出了一种新的轴孔内的同轴定位机构装置。根据机械技术领域的三点定心原理及六点定轴原理，利用机构中2个涨套的6个弹性爪与轴孔机械轴进行点接触，由于与轴孔内壁接触都是刚性接触，能够承受较大负荷从而实现光学测量装置光轴与轴孔机械轴的精密重合，达到高精度的定位及保持高精度的同轴状态。定位机构在实际中得到了很好的应用，理论和实践证明此定位机构能够很好地实现光学测量装置在轴孔内的高精度定位，精度能够达到10″以内，从而起到光学测量装置测量机构轴线的作用。

A new coaxial positioning device was proposed to overcome the disadvantage of existing technology, which realized high precision measurement in the shaft hole of optical measuring device. According to three points centering principle and six points axis locating principle, the point contact between six elastic claws and the mechanical axis of shaft hole is a kind of rigid contact and it can bear higher load, and the optical axis of measuring device and mechanical axis of shaft hole can achieve precise coincidence, which makes high precision positioning and good coaxiality possible. It was proved that the positioning device could enable optical measuring device to position accurately in shaft hole with the precision of 10″ in theory and in practice.