传动轴是汽车传动系中传递动力的重要部件，它的作用是与变速箱、驱动桥一起将发动机的动力传递给车轮，使汽车产生驱动力。 传动轴是由轴管、伸缩套和万向节组成。伸缩套能自动调节变速器与驱动桥之间距离的变化。万向节是保证变速器输出轴与驱动桥输入轴两轴线夹角的变化，并实现两轴的等角速传动。
Drive shaft is an important part of transmission power in automotive transmission system. Its function is to transfer engine power to the wheel together with transmission box and drive axle, so as to generate driving force for automobiles. The transmission shaft is composed of a shaft tube, a telescopic sleeve and a universal joint. The telescopic sleeve can automatically adjust the distance between the transmission and the driving axle. Universal joint ensures the change of angle between output axle of transmission and input axle of drive axle, and realizes equal angular speed transmission of two axes.