1. Bearing radial load

The bearings that mainly bear radial loads are radial bearings. The nominal contact angle a₀≤45° of this type of bearing. Roller bearings of the same size can withstand greater radial loads than ball bearings.

N-type and NU-type cylindrical roller bearings can only bear radial loads, while other types of radial bearings can bear both radial loads and axial loads.

2. Axial load of bearing

The bearings that mainly bear axial load are generally thrust bearings, and their nominal contact angle a₀>45°. Thrust bearings and thrust angular contact ball bearings can withstand axial force in one or two directions at the same time depending on their structure. When the thrust force is particularly high, thrust cylindrical roller bearings and thrust spherical roller bearings are preferred.

Thrust spherical roller bearings and unidirectional thrust angular contact ball bearings can bear both axial load and radial load, while other thrust bearings can only bear axial load.

3. Length compensation of the bearing itself

Supporting a shaft and bearings usually uses a combination of fixed bearings and traveling bearings. Traveling bearings compensate for shaft length errors and thermal expansion.

NU type and N type cylindrical roller bearings are ideal sliding bearings. These bearings can compensate for their own length. The inner and outer rings of the bearing can be tightly fitted.

Length compensation for sliding fits

Non-separable bearings (such as deep groove ball bearings and spherical roller bearings) can also be used as traveling bearings. One of the two rings of this type of bearing is fitted and has no axial fixing surface. Therefore, one ring of the bearing can move on its bearing surface.

4. Separable bearings (accuracy)

This is a bearing whose rings can be installed separately. Its advantages are very prominent when both rings are tightly fitted.

Separable bearings include four-point contact ball bearings, double-row angular contact ball bearings with double half inner rings, cylindrical roller bearings, tapered roller bearings, thrust ball bearings, thrust cylindrical roller bearings and thrust spherical roller bearings.

Non-separable bearing types: deep groove ball bearings, single row angular contact ball bearings, aligning ball bearings, pendant roller bearings and spherical roller bearings.

Accuracy

In most cases rolling bearings of normal dimensions and rotational accuracy are sufficient. When requirements are higher, bearings require higher accuracy grades, (for example: machine tool spindle bearings).