According to the latest rolling bearing fatigue life theory, an excellent design, superior materials, sophisticated manufacturing and installation of the correct bearing. As long as its easy enough to bear the load (not greater than the corresponding bearing a persistent load limit value), then the bearing material will never fatigue damage. Therefore, if the bearing temperature suitable working environment and changed slightly, absolutely no solid dust, harmful gases and moisture intrusion bearings, bearing lubrication adequate and right, lubricants absolutely pure without impurities, and no aged deterioration ...... , then the bearings will indefinitely afloat.

The significance of this theory is that it not only provides a lifetime than the ISO more reliable prediction equation of modern life instrument bearings, and that it shows all the rolling bearing fatigue life have a considerable development potential, and shows the development of this potential way, thus bearing product development, quality management and application of technology has a profound impact.

However, bearing only the infinite possible under laboratory conditions "realization", while bearing in such conditions for certain conditions of use in the field, it is also difficult to apply both too expensive.

Bearing field use, their work load is often greater than the corresponding persistent fatigue limit load at work after a certain period of time, early or late, or because of their material always call up to the fatigue limit, resulting in fatigue spalling can not continue to use. Even some of the work load bearing less than its corresponding persistent load limit, also due to the difficulty bearing pollution extermination wear failure occurs. In short, on-site use of bearing more or less can not fully equipped laboratories have those conditions as described above, of which slightly less than either of these conditions will shorten the bearings in the period, which resulted in the issue of the bearing life.

In general, it refers to the life of rolling bearings rolling bearings under actual service conditions (including working conditions, environmental conditions and the care and maintenance conditions, etc.), can continue to maintain the performance and accuracy of work expertise and services offered to meet the deadline.