Bearings are precision parts, so they need to be used with great care. Even if high-performance bearings are used, if they are not used properly, they can not achieve the expected performance effect, and they are easy to be damaged. However, under some special operating conditions, the bearing can obtain longer life than traditional calculation, especially under light load. These special operating conditions are when the rolling surface (track and rolling element) is effectively separated by the lubricating oil film and limits the possible surface damage caused by pollutants. In fact, under ideal conditions, the so-called permanent bearing life is possible. The service life of rolling bearing is defined by the number of revolutions (or working hours at a certain speed). The bearing within this service life shall have preliminary fatigue damage (peeling or damage) on any bearing ring or rolling body. However, no matter in the laboratory test or in the actual use, it is obvious that the actual life of bearings with the same appearance under the same working conditions is quite different. In addition, there are several different definitions of bearing "life", one of which is the so-called "working life". It means that the actual life that a bearing can achieve before damage is caused by wear and damage, which is usually not caused by fatigue, but by wear, corrosion, seal damage and other reasons.


In fact, only part of the bearings are damaged due to wear in practical application, and most of the bearings are damaged for many reasons - beyond the original estimated load, ineffective seal, too tight fit resulting in too small bearing clearance, etc. any of these factors has its special damage type and will leave special damage traces. Therefore, in most cases, it can be found that the possible causes of the damaged bearings are, in general, one-third of the bearing damage is due to fatigue damage, the other one-third is due to poor lubrication, and the other one-third is due to pollutants entering the bearing or improper installation.