To provide a rolling technique for a gear material, by which rolling technique, a gear product with an accurate tooth shape can be obtained.
The gear material before rolling has such a tooth shape that when the whole depth is represented by hf, the dedendum from its pitch point toward its root side is represented by ht, and the addendum from its pitch point toward its outside diameter side is represented by hk, an approximately triangular projection is provided on the respective tooth flanks over the dedendum side and the addendum side so as to place its apex on the pitch point with its straight sides tilted. The gear material is rolled so as to satisfy the following expressions, 0.25ht≤b≤0.85ht, 0.25hk≤c≤0.85hk, 0.25ht≤d≤0.25hk, where "a" shows the full length of the projection including the pitch point, "b" shows the length of the projection on the dedendum side, "c" shows the length of the projection on the addendum side, and "d" shows the difference between the pitch point and the apex of the projection.
TAKEMASU MITSUIE
AMANO SHUICHI
Sadao Enjoji
Next Patent: METHOD FOR MANUFACTURING GEAR