Angular contact ball bearing fatigue life is in a certain technical conditions, structure, process condition, cooperate, installation, clearance and lubrication condition, etc.) of the scroll angular contact ball bearing, in the operation of the host, until the roll surface fatigue spalling and cannot meet the requirements of the host of angular contact ball bearing inner and outer ring (axis, seat) relative to total number of revolution - the total number of turns.

When the rotational speed of angular contact ball bearing is roughly constant, the fatigue life can be expressed as the total operating hours corresponding to the total revolutions.

The influencing factors of angular contact ball bearing fatigue life very much, when can't all be estimated or through standard test conditions and to eliminate, this can make the actual fatigue life of angular contact ball bearing is a large discreteness, so the angular contact ball bearing fatigue life calculation and test is based on mathematical statistics and probability theory.

The most commonly used expression parameter of the fatigue life of the rolling angular contact ball bearing is rated life L10. The meaning of L10 is clearly stipulated in ISO recommendation Standard R281 as follows:

"A sufficient number of the same batch of angular contact ball bearings, with a rated life of L10.In terms of revolutions (or hours at constant speeds), 90% of the angular contact ball bearings reach or exceed this revolution (or hours) before fatigue spalling occurs ".So far, all parts of the world have complied.

In some countries, such as the United States, the concept of median life span is also used.Median life Lm refers to the median life of a batch of ball bearings with the same angular contact, that is, the total number of revolutions that 50% of the angular contact ball bearings can achieve or exceed before fatigue spalling, or the number of working hours at a certain speed.

The median life Lm is not the arithmetic mean of the life of a batch of angular contact ball bearings.The average life is 5 times of the rated life.The concept of rated life applies only to a sufficient number of angular contact ball bearings, not to individual angular contact ball bearings.

For angular contact ball bearings which are not due to fatigue failure in actual use, the rated fatigue life is the expected life of these angular contact ball bearings when they give full play to their material potential.Therefore, in most cases, the user in the choice of angular contact ball bearing is still the first fatigue life calculation, and then according to the actual type of failure to check.