Flat thrust bearings primarily bear axial loads in assemblies and are widely used. Although the installation of thrust bearings is relatively simple, errors often occur during actual maintenance, specifically when the inner and outer rings are installed in the wrong positions. This renders the bearing ineffective and causes rapid wear on the journal. The inner ring of the thrust bearing has a transition fit with the journal, leading to rapid wear on the journal. The inner ring of the tight ring has a transitional fit with the journal. When the shaft rotates, it drives the tight ring, causing friction with the end face of the stationary component. When subjected to an axial force, the frictional torque exceeds the resistance torque of the inner diameter fit, causing the tight ring to rotate relative to the shaft mating surface and accelerating journal wear.

Therefore, the following points should be noted when installing thrust bearings:

1. Distinguish between the bearing’s tight ring and loose ring.

2. Identify the stationary components of the mechanism.

3. Under all circumstances, the bearing’s loose ring must always rest against the end face of the stationary component. In any case, the distinction between single-direction and double-direction thrust ball bearings lies in their design.

A single-direction flat-bottom thrust ball bearing typically consists of a row of steel balls (with a cage), an inner ring (tightly fitted to the shaft), and an outer ring. The outer ring has a clearance fit with the bearing housing bore, and the steel balls rotate between the inner and outer rings. Primarily, it can only withstand axial loads in one direction and cannot withstand radial loads at all. Since the axial load is evenly distributed across each ball, the load-carrying capacity of a single-direction flat-bottom thrust ball bearing is quite high; however, because it experiences a relatively large temperature rise during operation, it has a high permissible limiting speed. Although single-direction flat-bottom thrust ball bearings cannot restrict radial movement of the shaft or housing, they can limit axial movement in the same direction for both the shaft and housing. Therefore, these bearings are often used in combination with deep groove ball bearings for better performance.