How to Calculate the Basic Rated Life of Bearing?

Nov 01, 2022

The life calculation of rolling bearings is based on the life theory of Lundberg and Palmgren in Sweden, which solves the problem of calculating the load carrying capacity and fatigue life of rolling bearings and is recognized by all countries in the world, and later developed into ISO standard. Corresponding to our national standard GB/T6391-2010/ISO281:2007 "rolling bearing rated dynamic load and rated life" and GB/T4662-2003/ISO76:1987 "rolling bearing rated static load".

ball bearing 6204

The basic rated life of rolling bearing is calculated by the formula:

L10=（C/P）^ε

Where: L10 - basic rated life (million revolutions).

C - basic dynamic load rating, N.

P - equivalent dynamic load,N.

e - life index

Ball bearing ε=3

Roller bearing = 10/3

The fatigue life of the bearing when it is used at a certain speed, it is convenient to use time to express. Cars, vehicles, etc. are generally expressed in terms of the number of kilometers traveled.

If the basic rated life of the bearing is expressed in time, then the life calculation formula is:

L10h=1000000/60n*(C/P)^ε

Where: L10h - basic rated life, h

n - rotational speed, r / m

1) The basic rated life L10 of radial ball bearing is:L10=(Cr/Pr)^3

2) The basic rated life L10 of thrust ball bearing is:L10=(Ca/Pa)^3

3) The basic rated life of radial roller bearing L10 is:L10=(Cr/Pr)^(10/3)

4) The basic rated life of thrust roller bearing L10 is:L10=(Ca/Pa)^(10/3)

Where: Cr - radial basic dynamic load rating, N;

Ca - axial basic dynamic load rating, N;

Pr - radial equivalent dynamic load, N;

Pa - Axial equivalent dynamic load, N.