| 摘要 |
<p>A rotary drive comprises an annular sun gear, a planetary gear meshing the sun gear and revolving about the central axis (O) of the sun gear, a fixed annulus gear arranged fixedly and coaxially with the sun gear and meshing the planetary gear, a movable annulus gear having the number of teeth different from that of the fixed annulus gear and arranged rotatably and coaxially with the sun gear to mesh the planetary gear, and a drive motor for rotating the sun gear about the central axis. The movable annulus gear is provided with a tubular output shaft held by an annular rotation supporting member. The drive motor has a drive shaft arranged to bias for the central axis (O) of the sun gear. A through hole extending along the central axis (O) is provided on the inner circumferential side of the sun gear.</p> |
