| 摘要 |
PURPOSE:To achieve highly accurate positioning feature, direct advance stroke in mm unit, and highly accurate angular positioning feature by providing a second ultrasonic motor for regulating the rotation in addition to a first untrasonic motor and further providing a screw and nut coupling mechanism for converting the rotation into direct advance motion. CONSTITUTION:Upon operation of only R side rotor 7, nut 21 side of a ball screw rotates but since the rotation is limited by the restricting force of an L side ultrasonic motor, an output shaft 30 moves only in the axial direction. When the output shaft 30 is moved only in the rotary direction, it is required to rotate L side and R side rotors 17, 7 in same direction at same speed. By such arrangement, direct advance function provided with positioning resolution finer than 1 micron and stroke longer than 1mm can be combined with rotary function provided with angular positioning resolution shorter than 30sec and movable range of 360 deg.. |
