Selection of bearing structure

The types of machinery are different, the service conditions of bearings will be different, and the performance requirements are not only the same, but generally speaking, there are no less than two bearings on a shaft. Moreover, in order to facilitate axial positioning, most of them use one bearing as the fixed end bearing and the rest as the free end bearing.
The fixed end bearing is used for axial positioning and fixing of the bearing
Select bearings that can bear radial load and axial load at the same time
In order to bear bidirectional axial load, the corresponding strength shall be considered according to the axial load during installation. For example: deep groove ball bearing, combined angular contact ball bearing, double row angular contact ball bearing, self-aligning ball bearing, cylindrical roller bearing with flange, double row tapered roller bearing and self-aligning roller bearing.
Free end bearing
It is used to avoid the expansion and contraction of the shaft caused by the temperature change during operation, and to adjust the axial position of the bearing.
The bearing that only bears radial load and the inner ring and outer ring can be separated should be selected.
When using non release bearings, clearance fit is generally adopted between the outer ring and the housing, so that axial avoidance can be made together with the bearing when the shaft is telescopic. Sometimes, the mating surface of the shaft and the inner ring is also used for axial avoidance. For example: separate type: cylindrical roller bearing non separate type: deep groove ball bearing, combined angular contact ball bearing, double row angular contact ball bearing, self-aligning ball bearing, double row tapered roller bearing and self-aligning roller bearing.
When not fixed end and free end

When the bearing spacing is small and the influence of shaft expansion is small, two angular contact ball bearings or tapered roller bearings that can bear axial load are used in front or configuration. Adjust the installed axial clearance with nuts or gaskets. For example: deep groove ball bearing, angular contact ball bearing, self-aligning ball bearing, cylindrical roller bearing, tapered roller bearing, self-aligning roller bearing.
For vertical shaft
The fixed end shall be a bearing that can bear both radial load and axial load. When the axial load of the bearing with axial load is large, the thrust axial and radial bearings shall be used together. Similarly, the free end can select the bearing with both axial radial load and axial load to avoid the expansion and contraction of the shaft. For example: fixed end: combined angular contact ball bearing, double row tapered roller bearing, thrust bearing and radial bearing.