The track mounted on the shaft is called the inner wheel, and the one mounted on the bearing box is called the outer wheel.
The inner wheel and the outer wheel are provided with circular grooves for ball rolling. The bearing box can only bear single bearings with axial load in the direction and compound bearings with axial load in both directions. The wheel of compound thrust ball bearing is fixed on the shaft by a shoulder ring, a sleeve ring and a bolt mounted on the shaft.