Method for rotationally driving gear material when hob machining is performed, and gear

摘要

In order to rotationally drive a gear material (3) when the gear material (3) is gear machined using a hob (not shown), a drive hole (34) having a circular configuration in section and extending on an axis L of the gear material (3) is formed in an end face (3e) of the gear material (3) and a shaft member (4) having a polygonal configuration is employed. The distance from an axis of this shaft body (4) to each angular portion (4a) is larger than the radius of the drive hole (34). The distance from the axis of the shaft member (4) to each side portion (4b) of the shaft member (4) is smaller than the radius of the drive hole (34). The shaft member (4) is fitted, under pressure, in the drive hole (34) and the gear member (3) is rotationally driven through this shaft member (4)