CRUCIFORM-SHAFT UNIVERSAL JOINT AND METHOD FOR PRODUCING SAME

摘要

[Problem] To achieve a structure for a cruciform-shaft universal joint whereby it can be easily determined, even post factum, that an excessive torque has been applied to the universal joint due to a collision accident or driving operation error. A ridge (20), the shape of which appears rectilinear seen from an outside surface side of coupling arm parts (15c) constituting a yoke (12c), is formed on the outside surface of the coupling arm parts (15c). When an excessive torque is applied and the coupling arm parts (15c) deform plastically, the ridge (20) changes from being rectilinear to being non-rectilinear. This change makes it possible to easily check for whether an excessive torque has been applied to the cruciform-shaft universal joint including the yoke (12c). The dimensions of each part of the yoke (12c) are regulated so as to satisfy 3 < L/D <= 4, where D is the spacing between inner surfaces of the coupling arm parts (15c) and L is the axial length of the coupling arm parts (15c).