Why the bearing axis of rotation is so hard?

Bearing as an important parts of machinery and equipment operation, when we find the bearing in the process of operation, the bearing axis always thought turned to be not moved, the so-called bearing axis of working hard? This is how the matter? According to practical situation, it also has a lot of people ask this variety problem, China bearing network for everyone to make relevant solutions. Why the bearing axis of rotation is so hard? General situation, main reason has the following several aspects, from the several aspects to stop thinking, and find the way to stop a good corresponding processing. 1, smooth, oil level too high or too low, bearing clearance, improper choice. 2, clean level does not reach the designated position, may have sundry. 3, oil seal, shoulder and sealing, locking piece ( The sun) The position such as inappropriate. 4, shaft concentricity wrong is, interspersed with positioning provoked axial jammed. 5, low accuracy of bearing box, and twisted.