Thermal deformation analysis of motorized spindle base on thermo-solid structure coupling theory

Machining different types of complex parts requires changing speed of the motorized spindle to accommodate the various processes, resulting in temperature rise or decline and then causing thermal deformation of machine tool, which plays a significant impact on the machining accuracy of the parts. According to the Law of Conservation of Energy and Fourier's Law of Heat Conduction, the heat transfer mechanism of the motorized spindle is investigated. Based on the thermo-solid structure coupling theory, the analytic models of the temperature field and thermal deformation for the motorized spindle are established, and the thermal hysteresis phenomenon is explored by means of the case studies. The characteristic experiments were carried out under variable working conditions and the model parameters were identified using Genetic Algorithm (GA). The accuracy and effectiveness of the proposed models for predicting temperature and thermal deformation of the spindle are validated which is applicable to compensate the thermal errors. Moreover, compared with data-driven modeling approach, our study needs lesser data for parameter identification, greatly saving the computation time in modeling.