Bearing parameters


life The number of revolutions or hours experienced by […]

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 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 laboratory tests or in actual use,

It can be clearly seen that under the same working conditions, the appearance of the same bearing, the actual life is very different. There are also 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

Wear and damage are usually not caused by fatigue, but by wear, corrosion, seal damage and other reasons.

To determine the bearing life standard, the bearing life and reliability are linked.

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, and the shortest is 0.1-0.2.

The ratio of the longest to the shortest life of the unit 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, 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. Centripetal thrust bearing is the radial component that produces pure radial displacement.