| As the main functional component of modern numerical control machine tool, the performance of hybrid bearing spindle has a great importance on the processing quality of the machine tool. In recent years, with CNC machine tools developing toward high speed, high efficiency and high precision, hybrid bearing, as a supporting part of the spindle, its design and manufacturing also face significant challenges. This paper,combining the project request, has made a profound research on hybrid bearing and the spindle sysytem:(1) Based on the constant hybrid bearing, a calculation of the four static pressure cavity of hybrid bearing was maked by using the fluid simulation software “Fluent”. Then the changes of the bearing’s performance under the condition of the different structural parameters and working parameters was analyzed. Finally, a hybrid bearing that meets the requirements of the project was found.(2) Based on the thought of changed clearance, this paper gives the structure of radial clearance changed bearing and axial clearance changed bearing. And the changed rule of their performance when the clearance of adial clearance changed bearing and axial clearance changed bearing changed ws explored by using the CFD method. Then, come to a conclusion that the radial clearance changed bearing’s performance is superior to the axial change bearing clearance, and at the same time, better than the bearing which clearance has not been changed. And a explanation of bearing stiffness changed rule from the angle of mechanic analysis of bearing was provided.(3) The static performance and dynamic performance of high precision grinding machine under different hybrid bearing spindle system was analyzed by using finite element analysis software ANSYS. According to the analysis of static performance, this paper obtained the deformation and stress of the spindle system under different supporting conditions. And the authou calculated the static stiffness of the spindle system including grinding wheel deformation. Through the dynamic performance analysis, calculated and compared the first eight natural frequency and mode variation of the spindle system under supporting by different bearings. At the same time, dynamic stiffness of the spindle system under supporting by different bearings. are given.Calculation shows that increasing stiffness of the bearing which supporting the spindle system can effectively increase the dynamic stiffness of spindle system.(4) The temperature of the spindle system with hybrid bearing was measured under different speed. |
