The invention provides a
thrust bearing for the screw of a ball-nut type steering gear. The
thrust bearing comprises a screw. A thrust
ball type thrust bearing is arranged on screw. The thrust
ball type thrust bearing comprises a
steel ball and a ring. The ring is composed of a left semi-ring and a right semi-ring. The cross section of the thrust
ball type thrust bearing raceway is a four
point contact type. The left semi-ring and the right semi-ring are both provided with a corresponding arc outer raceway. Two arc inner raceways are arranged on the screw. The
radius of two inner raceways is the same as that of two outer raceways. The centers of four arc raceways are in a same circumference, but four arc raceways are non-concentric. The
steel ball is arranged between the screw and the ring. Four contact points are formed between the
steel ball and two outer raceways and two inner raceways, and thus a four
point contact type thrust
ball bearing is formed. In
assembly, a
punching-riveting anti-loosening structure is adopted between an adjusting nut and a valve body. For the bearing, a screw is used to replace a shaft
washer, a holder is not needed any more, and the installation becomes convenient. The inner raceway and outer raceway are both composed of two arcs, a four
point contact ball bearing is formed and is capable of bearing a large axial / radial force, the wear is reduced, and the service life is prolonged.