Analytical Method Of Static And Dynamic Characteristics Of A Motorized Spindle And Its Application

High-speed machining is a rapid developing new technology in modern manufacturing industries. High-speed CNC machine tools are the basic equipments for high-speed machining. The motorized spindle is the critical unit of CNC machine tools which directly influence the machining efficiency and quality. Optimizing the motorized spindle based on the systematic study of its static and dynamic characteristics can significantly improve manufacturing performance.Firstly, the calculation method of the stiffness of rolling bearings which significantly influence the static and dynamic characteristics of the motorized spindle is presented in this thesis, then the quasi-dynamic model of the rolling bearing is established, which is complete and convenient for application compared to static and dynamic models, and the corresponding computer programs have been carried out. Secondly, Timoshenko beam model is prescribed for the journal of the spindle, and the stiffness of rolling bearings and their junction are set as supporting stiffness of the motorized spindle, then the calculating process of the static and dynamic characteristics of the motorized spindle has been driven using the FEM. Thirdly, a motorized spindle has been analyzed using the above established analytical method of the static and dynamic characteristics, and the analysis of the motorized spindle has been taken using ANSYS at the same time, then the two calculated results to experimental results has been compared, and it is concluded that the above established analytical method is particularly fit to develop motorized spindles, and is easy to build up or modify models and be enough exact. Lastly, after finishing the main designs of the motorized spindle, the influencing factors of the static and dynamic characteristics of the motorized spindle have been analyzed using the above established analytical method, and the size of structures of the motorized spindle have been optimized.The researches in this thesis have significant engineering value to the design and optimization of the motorized spindle.