Research on thermal deformation of large CNC gear profile grinding machine tools

Thermal deformation of large computer numerical control (CNC) gear profile grinding machine tools, which causes the position changes of grinding point between a grinding wheel and workpiece in X and Y directions, affects the machining accuracy significantly. In view of this situation, a theoretical model of thermal deformation based on the theories of thermal expansion of metallic materials, extensional axis of beam, non-uniform temperature distribution of Euler-Bernoulli beam, and Kirchhoff assumption of plane section is proposed according to the complex structure and machining process of the machine tools. To verify the accuracy and the reliability of the model, an experimental system and a platform for thermal deformation are established on a large CNC gear profile grinding machine tool, and the experimental data of temperature and displacement is measured and analyzed. Compared with theoretical value of displacement, the measurement data indicates that the relative errors are no more than 5 %. The proposed theoretical model and the adopted theories, technologies, and methods have great guidance significance and practical value to improve the accuracy of the machine tools effectively.