Development of high-speed aerostatic spindle with three independent cooling structures and evaluation of thermal characteristics under nonrotating conditions

Abstract

Thermal deformation of ultra-precision machine tool spindles significantly degrades machining accuracy. Therefore, effective countermeasures to suppress heat inside the spindle that causes thermal deformation are required. In this study, a high-speed aerostatic spindle with three independent cooling structures was developed to achieve high thermal stability, and its thermal characteristics were investigated. The fundamental cooling characteristics of the spindle cooling structures under nonrotating conditions were investigated experimentally. Furthermore, the thermal characteristics of the developed spindle were evaluated by thermal analysis with boundary conditions derived from experiments, specifically, the temperature distribution inside the spindle, which is difficult to determine experimentally. In addition, the effects of each cooling structure on the spindle shaft-end displacement and thermal deformation of the spindle body were evaluated.