| 摘要 |
PROBLEM TO BE SOLVED: To mold a worm wheel by a mold, and to improve strength of a tooth part without thickening the thickness of the tooth part. SOLUTION: A helical gear 2 is used instead of a worm wheel, and the thickness T of the tooth part 21 is set at an outer diameter L or less (T≤L) of a worm 1, and a projection part 24 connecting a single tooth 22 on both sides of the bottom 23 is formed in a part noninterfering with a worm 2 on one side in the axial direction at the bottom 23. Since mutually adjacent single teeth 22 are connected by the projection part 24, the strength of the single tooth 22 is improved, and the strength of the tooth part 21 is improved. Since the projection part 24 is formed so as to raise a level of the bottom 23, the thickness T of the tooth part 21 becomes the outer diameter L or less (T≤L) of the worm 2, and there is no need to secure an excessive space. COPYRIGHT: (C)2009,JPO&INPIT
|
