A universal joint, also known as a hooker joint, is usually used to transfer mechanical power between two axes at angles to each other. If you look at the power transfer of the rear car, they use universal joints. As shown in the figure below, two universal joints are required to transfer power from the engine to the differential.

The basic structure of universal joint

The universal joint mainly consists of three parts, two universal fork, and a cross shaft. The two universal joint forks are connected by a cross shaft. Such a structure makes the Angle range between the output shaft and the input shaft very large.