Thrust ball bearings is consist of the bearing ball (with cage),a shaft washer(matched with the shaft),a housing washer(matched with the bearing bore,but clearance between the shaft),the bearings ball is rolling between the shaft washer and housing washer.This type of bearing can only carry one direction axial load,can't carry radial load.Because the radial load distribute equably on every balls,the capacity of the load is big,but when work,the temperature got high,the rotate speed got lower.