Under the action of a certain load, the bearing in the event of pitting before the number of revolutions or hours, known as bearing life.
The life of a rolling bearing is defined in terms of the number of revolutions (or hours worked at a certain speed): A bearing within this life-cycle shall be subject to preliminary fatigue damage (peeling or defect) on any of its bearing rings or rolling elements. However, whether in laboratory tests or in actual use, can be clearly seen in the same working conditions, the appearance of the same bearing, the actual life is very different. In addition there are several different definitions of bearing "life", one of which is the so-called "working life", which means that a bearing before the damage can be achieved by the actual life is wear and tear, damage is usually not caused by fatigue, but From wear, corrosion, sealing damage and other reasons.
In order to determine the standard bearing life, the bearing life and reliability linked.
Due to manufacturing accuracy, material uniformity of the differences, even the same material, the same size of the same batch of bearings, under the same working conditions, the life span is not the same. If the statistical life of 1 unit, the longest relative life of 4 units, the shortest 0.1-0.2 units, the longest and shortest life of the ratio of 20-40 times. 90% of the bearings do not produce pitting, experienced by the number of revolutions or hours rated life of the bearing.