The universal joints are the very important components in mechanical engineering, and as the effect of stress concentration, the fork of the joint axis and the flat head are often damaged.
万向连接轴是许多工程机械的传动连接部件，由于应力集中的影响，连接轴的叉头和扁头经常发生破坏现象。
2
In this paper, why the second couple in the ring-fork U-joint occurs is analyzed.
本文分析了普通十字轴万向节内二次力矩产生的原因。
3
On the base of the second couple of the common cross U-jioint. a transient value of the second couple in the ring-fork U-joint is obtained.