Prediction of transient thermo-mechanical behavior of the headstock assembly of a CNC lathe

The demand for high-speed/high-precision machine tools is rapidly increasing in response to the development of production technology that requires high-precision parts and high productivity. The thermal deformation of the machine tool structure plays a critical role on the accuracy of machining. Heat generation in the bearings, chucking cylinder, and motor coil are the major sources of thermal deformation. This paper addresses the issues of the thermal displacements in the headstock assembly of a slant bed two-axis CNC lathe. Experimental and numerical investigations were carried out to gain insights into the extent of contribution made by the elements of the headstock assembly on the transient temperature rise and the resulting thermal deformation characteristics. The outcome of the work could be effectively used to improve the machine performance either by making suitable design changes or developing a robust error model for resorting to error compensation.