A method of fabricating a power transmission shaft

摘要

A method of fabricating a power transmission shaft having axial teeth in an outer periphery thereof in order to transmit torque between the teeth (21) and an associated member through tooth surfaces (21c), an end of a valley section (21a) of the tooth (21) leading to an outer surface of the power transmission shaft through a diameter expansion surface (22), the diameter of which is enlarged in an axial direction, wherein a first blunt section is provided in a corner (C1) between the diameter expansion surface (22) and the tooth surface (21c) adjacent to the diameter expansion surface (22) in order to blunt an edge between them,
the method comprising forming the blunt sections simultaneously with the teeth (21) during a form rolling step.