The number of revolutions or hours experienced by a bea […]
The number of revolutions or hours experienced by a bearing before pitting occurs under a certain load is called bearing life.
The life of a rolling bearing is defined by the number of revolutions (or the number of hours of operation at a certain speed): Bearings within this life are subject to initial fatigue damage (flaking or missing) on any of their bearing rings or rolling elements. However, whether in the laboratory test or in actual use, it can be clearly seen that the same bearing under the same working conditions has a different actual life. In addition, there are several different definitions of the bearing "life", one of which is the so-called "working life", which means that the actual life that a bearing can reach before it is damaged is caused by wear and damage, usually not caused by fatigue, but Caused by wear, corrosion, seal damage, etc.
To determine the bearing life standard, the bearing life is linked to reliability.
Due to the difference in manufacturing precision and material uniformity, even the same material, the same batch of bearings of the same size, used under the same working conditions, the lifespan is not the same. If the statistical life is 1 unit, the longest relative life is 4 units, the shortest is 0.1-0.2 units, and the ratio of the longest to the shortest life is 20-40 times. 90% of the bearings do not produce pitting, and the number of revolutions or hours experienced is called the bearing rating life .
Dynamic load rating
In order to compare the bearing capacity of the bearing against pitting, when the rated life of the bearing is specified to be one million revolutions (106), the maximum load that can be withstood is the basic dynamic load rating, expressed in C.
That is to say, under the action of the rated dynamic load C, the bearing has a reliability of 90% (100) without pitting failure, and the larger the C, the higher the bearing capacity.
Basic dynamic load rating
1. Radial bearing refers to pure radial load
2. Thrust ball bearings refer to pure axial loads
3. A radial thrust bearing is a radial component that produces a pure radial displacement.