| 摘要 |
PROBLEM TO BE SOLVED: To improve the work efficiency for pre-pressuring bearings by providing a member for finely adjusting the relative position of a rotor magnet to a stator coil of a motor for an oscillating mechanism to absorb the deviation of the mutual center position, thereby keeping the pre-pressure for the bearings always const. SOLUTION: A drive shaft 24 has a frame 20 and brushless d-c motor 31, the drive source, mounted on an outward protrudent part of the frame 10. The motor 31 has a rotor magnet 32 mounted on the drive shaft 24 and stator coil 33 disposed around the outer periphery of the magnet 32 with a predetermined very small clearance. An instruction value corresponding to the deviation of the relative position of the motor 32 to the coil 33 is given to a controller 36 to apply a given drive voltage to a piezoelectric element 35 of a fine adjuster mechanism, thereby keeping the pre-pressure applied to bearings always const. to improve the work efficiency. |
