UNIVERSAL JOINT

To provide a universal joint excellent in durability even in an inferior environment.SOLUTION: A universal joint 1 is equipped with a cross joint 2, a bearing 3 provided on each shaft of the cross joint, a pair of yokes 4 and 5 rotatably united with each other through the cross joint and the bearings, and a bearing cap 6 covering each bearing. On each joint surface of the yoke and the bearing cap, crests and troughs are alternately continued in a direction vertical to an axial direction of a shaft 2a gripped by the yoke and the bearing cap, and are formed into a saw blade shape in which they are engaged with each other. Assuming a surface on the bearing side of one saw blade of the yoke as a first surface F1, a surface on an opposite side to the bearing as a second surface F2, an angle formed by a surface V of the continuous troughs of the saw blade on which the yokes are continued and a first surface as a first angle θ1, an angle formed by the surface of the continuous troughs and a second surface as a second angle θ2, the first angle is larger than the second angle.SELECTED DRAWING: Figure 1 【課題】劣悪な環境下でも耐久性に優れる自在継手を提供する。【解決手段】十字軸２と、十字軸の各軸に設けられる軸受３と、十字軸及び軸受を介して互いに回動自在に結合される一対のヨーク４、５と、各々の軸受を覆うベアリングキャップ６とを備える自在継手１であって、ヨークとベアリングキャップの各々の接合面は、ヨークとベアリングキャップとで把持される軸２ａの軸線方向に対して垂直な方向に山と谷が交互に連続し、互いに噛み合う鋸刃状に形成され、ヨークの一つの鋸刃の軸受側の面を第１の面Ｆ１、軸受とは反対側の面を第２の面Ｆ２とし、ヨークの連続する鋸刃の谷底を連ねた面Ｖと第１の面のなす角を第１の角度θ１、谷底を連ねた面と第２の面のなす角を第２の角度θ２とした場合に、第１の角度が第２の角度よりも大きい自在継手。【選択図】図１