| 摘要 |
To facilitate an integrating operation and to make fabricating cost inexpensive. An idle gear 70 for transmitting rotation of an input gear 56 of a drive motor 54 to a cylindrical gear 61 is rotatably supported by an input side end portion of a specific one crank pin 40a, and therefore, the idle gear 70 may simply be supported by the crank pin 40a, further, a length in an axial direction of the cylindrical gear 61 brought in mesh with both of the idle gear 70, the input gear 60 is sufficiently to a degree of being more or less longer than a distance between remote side ends of the two gears 70, 60. |
