Thermal modelling of an HSC machining centre to predict thermal error of the feed system

Machine tools equipped with linear motors can achieve high feed speed as well as high accuracy. However, the direct feed drive system generates heat through power loss and friction. In combination with environmental influences such as machine shop climate, this can lead to a local deformation of the machine tool structure and induce a direct positioning error. This paper presents a thermal model, using the finite element method, to simulate the thermal behaviour of a high-speed cutting machining centre equipped with linear motors. This model considers the complex boundary conditions such as heat sources, contact and convective heat transfer. Transient changes in temperatures and deformations are allowed in the solution. The comparison of the experiments show that this model can predict the temperature distribution and positioning error under specified operating conditions very well.