Soichi Ibaraki, Kyoto University

A built-in-motor spindle system eliminates the necessity of mechanical transmission components such as belts, reduction gears, etc, resulting in reduced vibration and noise. Therefore, built-in-motors have been widely used in advanced machine tools in order to achieve high speed and accuracy. A rotary table is conventionally driven by a worm gear or other mechanical mechanisms with disadvantages such as limited rotation speed and backlash existence. Direct drive for rotary motion is gradually being adopted. Using direct drive motor for rotation axis motion has been considered to be crucial technology in enhancing the performance of an integrated machine tool. Many studies have been conducted for the application of direct drive in rotary table motion, but not for the application of direct drive in rotary axis as of yet. In this study, a direct drive motor used for driving a rotation axis in an integrated machine has been developed.