The universal joint of a car is a key component for achieving variable angle power transmission, which can reliably transmit power in the case of constantly changing angles between the two axes, and is widely used in automotive transmission systems. It can be divided into non constant velocity universal joints, quasi constant velocity universal joints, and constant velocity universal joints. Through special structural design, it ensures the continuous and stable rotation of the driving wheels, maintains power transmission during car turning and bumpy driving, and plays an indispensable role in the flexibility and reliability of car driving....