Thrust ball bearings are designed to withstand thrust loads at high speeds, consisting of gasket rings with ball rolling raceway grooves. Because the ring is cushion, therefore, thrust ball bearing is divided into two types: flat bottom cushion type and center adjusting spherical cushion type. Besides, the bearing can bear axial load, but it can't bear radial load. This kind of bearing is only suitable for the parts with one axial load and low speed, such as crane hoisting hook, vertical pump vertical centrifuge, Jack, low speed reducer and so on. Bearing rings, seat rings and rolling bodies are separated, and they can be assembled and disassembled separately.