Thrust bearings are a special type of sliding bearings, which are double-row cylindrical roller bearings composed of a pair of meshing bearing parts. Thrust bearings have a simple structure and do not require lubrication or sealing to prevent contamination and corrosion. They are suitable for situations where large shaft loads are not required but high-speed rotation is not possible. Thrust bearings are divided into thrust ball bearings and thrust roller bearings.

Thrust ball bearings are mainly composed of a bearing seat and a set of spherical rollers. The inner ring has two spherical rolling elements, which are installed on the two sides of the bearing seat, and the rollers are connected to the raceway of the other end face through the inner ring. The bearing seat is one of the two cylindrical holes fixed to the base by bolts, and a rotatable bolt is installed on it. The cylindrical hole is cylindrical and has a certain distance relative to the two spherical rolling elements. It is the largest gap between the bearing seat and the spherical rolling element. The spherical roller is composed of a raceway with a spherical rolling element connected by a thread or gear and in contact with the other end surface. Corresponding to the inner ring, the roller tooth shape is a semi-conical boss (or "concave spherical") rather than a truncated cone (or "convex spherical").