| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly precise resin helical gear with a helically shaped tooth portion on the outer peripheral face and a rib integrated therewith via which a boss is connected to a rim. SOLUTION: The resin helical gear is integrally formed as a whole with the boss 14 at the center connected to the cylindrical rim 12 via the rib 15. The rib 15 has a face twisted around the center shaft of the helical gear 10 in the same direction as that of the tooth portion 11, and the lead of the rib 15 is the same as the lead of the tooth portion 11. The position of the rib 15 on the rim corresponds to the position of the tooth bottom of the helical gear. The thickness of the rib 15 is changed in the axial direction of the helical gear and it is smaller in a gear removing direction when removing the helical gear from a forming die. COPYRIGHT: (C)2007,JPO&INPIT |
