Thermal Deformation of an Ultraprecision Machine Tool due to Environmental Temperature Change : Analysis of Thermal Characteristics by Transfer Function and Estimation of Deformation by Convolution Integral

Abstract

The present paper deals with the thermal behavior of the main spindle system of an ultraprecision machine tool as affected by a change in the temperature of the ambient air. First, it is found that the thermal deformation increases with an increase in the rotational speed of the spindle, which is considered to be caused by an increase in the heat transfer coefficient. The transfer functions between the ambient temperature variation and the thermal deformation of the machine are obtained experimentally for various rotational speeds, and the thermal behavior of the machine is analyzed. Second, a simple method of estimating the thermal deformation for future control of machining accuracy by utilizing the measured transfer functions and the convolution integral is proposed.