Thermal error analysis for a CNC lathe feed drive system

The development of high-speed feed drive systems has been a major issue in the machine tool industry for the past few decades. The resulting reduction in the time needed for tool changes and the rapid travel time can enhance productivity. However, a high-speed feed drive system naturally generates m ore heat and resultant thermal expansion, which adversely affects the accur acy of machined parts. This paper divides the feed drive system into two pa rts: the ball screw and the guide way. The thermal behavior model for each part is developed separately, in order to estimate the position errors of t he feed drive system caused by thermal expansion. The modified lumped capac itance method (MLCM) and genius education algorithm (GEA) are used to analy se the linear positioning error of the ball screw. Thermal deformation of t he guide way affects straightness and introduces angular errors, as well as affecting linear positioning. The finite element method is used to estimat e the thermal behavior of the guide way. The effectiveness of the proposed models is verified through experiments using a laser interferometer. (C) 19 99 Elsevier Science Ltd. Ail rights reserved.