2020 Long Bearing Life The Bearing Clearance is the Secret

Bearing life refers to the number of revolutions or hours that the bearing has experienced before pitting occurs under a certain load.

What is the bearing clearance?

In short, rolling bearing clearance is the clearance (or interference) between a single bearing or a system of several bearings. Clearance has two types: axial clearance and radial clearance. It depends on the bearing types and the measurement method.

Why adjust bearing clearance to extend bearing life?

For example, cooking with too much or too little water can affect the taste of rice. Similarly, if the clearance is too large or too small, it could reduce the bearing working life and even affect the stability of the whole equipment. 

Bearing types suitable for different adjustment methods

Different bearing types determine the different methods of clearance adjustment. 

Non-adjustable clearance bearing means that the bearing clearance is certain after the bearing leaves the factory. Therefore, deep groove ball bearing, self-aligning ball bearing, and cylindrical bearing belong to this category.

 

Clearance adjustable bearing means that moving the bearing raceway relative axial position to obtain the required clearance. Belonging to this category are tapered bearings and angular contact ball bearings and some thrust bearings.

 

Bearing clearance adjustment classification

For the clearance of non-adjustable bearing, the industry has corresponding standard values (CN, C3, C4, etc.). Also, the factory can custom specific clearance ranges. When we know the shaft size and bearing seat size, we can determine the corresponding amount of fit between the inner and outer rings. And the clearance after installation is unchangeable. Since the fit amount is a range in the design stage and there is also a range in the final clearance. It is not applicable in applications that require clearance accuracy.

Adjustable bearing solves this problem well. By changing the relative axial position of the raceway, we can get a definite clearance value. when we move the inner ring position we can roughly get the positive and negative gaps.