| 摘要 |
PROBLEM TO BE SOLVED: To provide an inscription engagement planetary gear mechanism capable of restricting reduction in a torque transmission efficiency and a variation in transmission torque.SOLUTION: A rotary shaft 33 has a second eccentric part 61 arranged on a second eccentric axis AX3. The second eccentric axis AX3 is positioned at an opposite side of a first eccentric axis AX2 in respect to a rotary axis AX1. A speed reducer 13 has a disc 62 arranged inside an inner gear 41. The disc 62 is rotatably supported by the second eccentric part 61 around the second eccentric axis AX3. A relation of {(D1/2)-E1}<{(D3/2)+E2} can be established, where E1 is a distance between the rotary axis and the first eccentric axis, E2 is a distance between the rotary axis and the second eccentric axis, D1 is a tooth tip circle diameter of the planetary gear, D2 is a tooth bottom circle diameter of the planetary gear, and D3 is an outer diameter of the disc. With this arrangement as above, the disc 62 is contacted with the tooth tip of the inner gear 41 prior to the tooth tip of the planetary gear 42 at a non-engaged portion and additionally a displacement of the planetary gear 42 toward the non-engaged side is restricted.SELECTED DRAWING: Figure 4 |
