Analysis of Thermal Deformation of an Ultraprecision Air Spindle System

Abstract

Thermal behavior of the main air spindle system of an ultraprecision machine tool is analyzed experimentally. Influences of the heat generated due to the spindle rotation and the temperature variation of the ambient air are considered. It is found that the thermal deformation due to the ambient temperature change increases with an increase in the rotational speed, which is considered to be caused by an increase in the heat transfer. The transfer functions between the rotational speed of spindle and the thermal deformation and between the ambient temperature and the thermal deformation are obtained separately. A simple method to estimate and compensate the thermal deformation is proposed by utilizing the measured transfer functions and the convolution integral, and machining errors due to the above two heat sources are successfully reduced to less than 15%.