Abstract
A concave conical gear is a new type of a conical gear. The concave conical gear has higher tooth durability than the conventional conical gear. So the concave conical gear has the possibility to be used instead of the bevel gear. However, the hobbing method of this gear has not been developed so far. This research presents a new hobbing method to cut the concave conical gear correctly. Test gears are cut and measured, and it is proven that the new hobbing method is practical utility in producing the concave conical gear.
