| 摘要 |
<P>PROBLEM TO BE SOLVED: To further improve static strength and fatigue strength while suppressing stress concentration to a prescribed part. <P>SOLUTION: A shaft tooth part 22 has a crest part 22a composed of a twisted shape whose axis intersects with the axis of a shaft (a crest part of a hub tooth part). The hub tooth part 28 has a crest part 28a which is composed of a linear shape with a constant tooth thickness and keeps inner diameter variable from the end part toward the side of a shaft shank 24. A first level-difference part 30 swelling toward the side of the hub tooth part 28 is formed to a trough part 22b of the shaft tooth part 22. A second level-difference part 32 recessed in the direction opposite to the side of the shaft tooth part 22 is formed to the crest part 28a of the hub tooth part 28. A starting point (P1) of the first level-difference part 30 and that (P2) of the second level-difference part 32 are respectively set at a position offset by a prescribed distance (L4). <P>COPYRIGHT: (C)2007,JPO&INPIT |
