Bearing clearance is the clearance (or interference) inside a single bearing or a system composed of several bearings. The clearance can be divided into axial clearance and radial clearance, which depends on the bearing type and measurement method.
Why should the bearing clearance be adjusted?

If the bearing clearance is too large or too small, the working life of the bearing and even the stability of the entire equipment operation will be reduced.

The method of clearance adjustment is determined by the bearing type, which can generally be divided into non-adjustable clearance bearings and adjustable bearings.The non-adjustable clearance bearing means that the clearance of the bearing is determined after the bearing leaves the factory. The well-known deep groove ball bearings, self-aligning bearings, and cylindrical bearings all belong to this category. Adjustable clearance bearing means that the relative axial position of the bearing raceway can be moved to obtain the required clearance. In this category, there are tapered bearings, angular contact ball bearings and thrust bearings.

For non-adjustable bearing clearance, the industry has corresponding standard values (CN, C3, C4, etc.), and specific clearance ranges can also be customized.

The choice of the best working clearance is determined by the application conditions (load, speed, design parameters) and expected working conditions (maximum life, best stiffness, low heat generation, ease of maintenance, etc.).