Due to different states of centripetal bearing, clearance is divided into three kinds:
1. Original clearance refers to the clearance of the bearing in the free state before installation.
2. The clearance refers to the clearance after the bearing is installed on the shaft of the machine part or in the box hole. Because the bearing is installed with interference fit, the fit clearance is always smaller than the original clearance.
3. Working clearance refers to the bearing at work, because of the temperature difference between the inner and outer rings, the matching clearance is reduced, and because of the work load. The rolling body and the ring produce elastic deformation and the clearance increases. Therefore, in general, the working clearance is greater than the platform clearance.
The clearance of the general centripetal bearing cannot be adjusted, but the centripetal bearing with tapered holes (such as 318200) can also achieve the purpose of adjusting the clearance by changing the tightness of the inner ring of the bearing during installation. The above relationship between original clearance, fit clearance and working clearance only exists for centripetal bearings, but not for adjustable bearings (centripetal thrust bearings and thrust roller bearings).