When the cylindrical shell (driving shaft) rotates, the spherical roller will drive the three pivots to rotate with it, and the three pivots are connected with the driven shaft by splines, so as to drive the driven shaft to rotate and realize the power transmission. When there is no angle between the output shaft and the input shaft, the three pivots and the spherical roller are in the raceway of the cylindrical shell. Because of the automatic centering function of the three pivots, the axes of the two shafts can coincide, and the two shafts can drive at the same speed. When there is an angle α between the output shaft and the input shaft, with the inclination of the three pivots journal, the spherical roller slides along the needle, so that the spherical surface of the spherical roller coincides with the raceway spherical surface of the cylindrical shell The contact generatrix formed is also the conjugate curve of cylindrical shell and spherical ring, which can ensure that the force transmission point of spherical roller is always on the bisector of the intersection angle of two shafts, and also has the characteristics of constant speed transmission.

The three pivot universal joint has the advantages of simple structure, small volume, light weight, good lubrication, fast heat dissipation, large bearing capacity and reliable operation, so it is widely used in the front and rear drive axle of automobile, especially in the small and medium displacement car with light weight design and difficult layout.