| 摘要 |
PROBLEM TO BE SOLVED: To provide a helical gear which is small in a cumulative pitch error of a helical tooth, and easy in manufacturing.SOLUTION: This helical gear 1 comprises a hollow hole 2 and helical teeth 3 formed at an external peripheral part, and is formed by forging. A tooth bearing face bearing with the other gear to be engaged is not applied with crowning treatment, and a cumulative pitch error of the forged helical teeth 3 is not larger than N6 of an accuracy class in a cumulative pitch error regulation list which is regulated by an internationally standardized standard. |
