| 摘要 |
PURPOSE:To improve precision and to enable reduction of a cost, by decreasing the number of parts. CONSTITUTION:A first gear 2, coaxially connected with a control shaft 1 so that they are simultaneously rotated, is located, and a planetary gear 3, having a gear part 3a geared with a gear part 2b of the first gear 2, is provided. A third gear 4, located coaxially with the first gear 2 and having a gear part 4a having length shorter than that of the gear part 3a of the second gear 3 and geared with the gear part 3a of the second gear 3, is provided, and the third gear 4 is secured to a mounting part located at the outside. Further, a fourth gear 5, being coaxial with the control shaft 1 and geared with the rest teeth part of the second gear 3, is provided, and a driving shaft 7 is connected with the fourth gear 5. This constitution provides a decreased reduction ratio by means of the increased number of parts, and permits improvement of precision. |
