Basic concepts and terminology related to rolling bearings

1, life

Refers to a set of rolling bearings in which one ring (or washer) or the number of revolutions of one ring (or washer) relative to another ring (or washer) before the first signs of fatigue spread of the rolling material.

2. Reliability (that is, reliability of bearing life)

The percentage of a group of nearly identical rolling bearings operating under the same conditions that is expected to meet or exceed the specified life span.The reliability of a single rolling bearing is the probability that the bearing reaches or exceeds the specified life.

3. Static load

Load applied to the bearing when the relative rotation speed of the bearing ring or washer is zero (centripetal or thrust bearing) or when the raceway element is not moving in the rolling direction (linear bearing).

Dynamic and dynamic charge

The load applied to the bearing when the bearing ring or washer is rotating relative to each other (centripetal or thrust bearing) or when the rolling element is moving in the direction of the rolling (linear bearing).

5. Rated life

Life prediction based on radial basic rated dynamic load or axial basic rated dynamic load.

6. Basic rated life

Rated life associated with 90% reliability.

7. Radial basic rated dynamic load

Refers to a set of rolling bearings assumed to withstand a constant radial load, under which the basic rated life is one million revolutions.For a single row angular contact bearing, the load is the radial component of the load that directs the pure radial displacement between the bearing rings.

8. Axial basic rated dynamic load

A hypothetical constant central axial load applied to a rolling bearing under which the basic rated life of the rolling bearing is one million revolutions.

9. Radial (or axial) equivalent dynamic load

Refers to a constant radial load (or central axial load) under which the rolling bearing has the same life as the actual load.

10. Radial (or axial) basic rated static load

Refers to the radial static load (or central axial static load) corresponding to the total permanent deformation of the rolling body and raceway.If, under zero load, the roller and raceway (roller bearing) are or are assumed to be normal bus (full line contact), under the maximum contact stress, the total permanent deformation at the contact of the rolling body and raceway is 1/10000 of the diameter of the rolling body.For single row angular contact bearings, the radial rated load is the radial component of the load that causes the bearing rings to each other relative to the pure radial displacement.

11. Radial (or axial) equivalent static load

The radial static load (or central axial static load) will make the total permanent deformation at the contact of the rolling body and raceway under the maximum stress the same as the total permanent deformation under the actual load condition.