| 摘要 |
Between a magnet (11) on the side of an upper drum (2) and a magnet or electromagnet (12) on the side of a lower drum (3), a force of attraction is exerted. With this force of attraction, pre-load of about 2 Kg is applied to a ball bearing (5) in a direction of an axis, to increase stability of rotation of the upper drum (2). Since the upper drum (2) is borne by the axis (4) with one bearing (5), a center of rotation of the upper drum (2) relative to the axis (4) can be changed by changing a balance among forces of attraction of three magnets or electromagnets (12). With this constitution, a precision rotator which allows correction of the center of rotation can be provided. <IMAGE> |
