드로우바와 로터가 고속주축계의 동적 특성에 미치는 영향

The spindle system with a built-in motor can be used to simplily the structure of machine tools. to improve the machining flexibility of machine tools. and to perform the high speed machining. For more quantitative analysis of a built-in motor`s dynamic characteristics. that of the mass and stillness effects arc considered. And the drawbar in the spindle can be in various condition according to supporting stiffness between drawbar and shalt Therefore, in this paper following items are performed and analyzed I. Modal characteristics of the spindle. 2. Analysis of rotor`s mass and stiffness effects. 3. Modal characteristics of the spindle including drawbar, rotor and tool. The results show enough sf ff supports must be provided between shaft and drawbar to prevent occurring drawbar vibration lower lhan the natural frequency of I st bending mode of the spindle, and considering the mass and stiffness of built-in motor`s rotor is important thing to derive more accurate results.