The function of the universal joint is to transmit the power of the reduction gear with certain angle to avoid damage to the transmission shaft. The universal joints are divided into two types, 1) non-constant velocity joint, which is a commonly used cross shaft universal joint; 2) constant velocity joint, whose transmission characteristics are the driving shaft and the driven shaft. The angular velocity of rotation is equal.
With the non-constant velocity joints, the rotational angular speeds of the driven shafts are different in one revolution. In order to achieve constant speed rotation, they should generally be used in pairs, that is, two universal joints are installed at both ends of the transmission shafts. The universal joint forks at both ends are in the same plane; the driving shaft and the driven shaft are kept substantially parallel.
The constant-speed joints are used in the front axle-driven cars. One of the commonly used types is the ball-fork type constant velocity universal joint, which is mainly composed of a driven fork, a movable fork, a steel ball, a pin and a positioning steel ball. There is also the ball cage type constant velocity joint, which is composed of a star sleeve and a slave connected to the driving shaft. The spherical shell, the steel ball and the cage are connected by the moving shaft. Because of the large angle of the transmission allowed, the bearing capacity is strong, the structure is compact, and the disassembly and assembly is convenient.www.morayshaft.com