Whether the steering knuckle has obvious elasticity according to the torsion direction, it can be divided into rigid steering knuckle and flexible steering knuckle. Rigid steering knuckles transmit power by hinged connection of parts, which can be divided into unequal speed steering knuckles (such as cross-shaft type), quasi-constant speed steering knuckles (such as duplex, bump type, three-pin shaft type, etc.) and Constant velocity knuckle (such as ball fork type, ball cage type, etc.). The flexible steering knuckle transfers power by elastic parts, which has a buffering and damping effect.
unequal speed steering knuckle refers to a steering knuckle in which when the angle between the two shafts connected by the steering knuckle is greater than zero, the output shaft and the input shaft transmit motion at a varying instantaneous angular velocity ratio, but the average angular velocity ratio is 1. Quasi-constant velocity steering knuckle refers to a steering knuckle that transmits motion with an instantaneous angular velocity ratio equal to 1 when working at a design angle, while the instantaneous angular velocity ratio is approximately equal to 1 when working at other angles. The steering knuckle in which the output shaft and the input shaft transmit motion at an instantaneous angular velocity ratio equal to 1 is called a constant velocity steering knuckle.