Characteristics of bearing stiffness of a spindle with high stiffness water hydrostatic thrust bearing for ultra-precision machine tool

摘要

A spindle supported by water hydrostatic thrust bearings has been designed for ultra-precision machine tools. In this spindle design, we particularly aimed to design a water hydrostatic thrust bearing with higher bearing stiffness. The present paper describes the feature of the developed spindle and the water hydrostatic thrust bearing. The bearing stiffness of the spindle is then investigated theoretically and experimentally. The results indicate that the influence of the deformation of the spindle body due to the water pressure reduces the bearing stiffness. The experimental and simulation results show that the required bearing stiffness of 1 kN/μm can be obtained by designing smaller gap size by considering the influence of the deformation of the spindle.