| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce entering of fine particles having a predetermined particle diameter between a gear which comes into contact with the outer surface of a shaft and is rotated and the shaft. <P>SOLUTION: A planetary gear 114 has a first shaft hole 130 which comes into contact with the outer surface of the shaft 112 and a second shaft hole 132 which is formed in the end in an axial direction from the first shaft hole 130 and whose inner diameter is smaller than that of the first shaft hole 130. The shaft 112 has a shaft body 136 which comes into contact with the first shaft hole 130 and rotatably supports the planetary gear 114 and a small-diameter portion 138 by which a gap larger than the particle diameter of a carrier is formed between the small-diameter portion 138 and the first shaft hole 130 and between the small-diameter portion 138 and the second shaft hole 132. At this point, in the small-diameter portion 138, the gap larger than the carrier is formed between the small-diameter portion 138 and the first shaft hole 130 and between the small-diameter portion 138 and the second shaft hole 132. In addition, the gap in the axial direction by the shaft body 136 and the planetary gear 114 is larger than the carrier for instance also. <P>COPYRIGHT: (C)2008,JPO&INPIT |
