Factors affecting the fatigue life of bearing
|
| Time：2016.09.08 News Sources：Shandong Xinkaite bearing Co.,Ltd. Views：
|
General sense of bearing fatigue life refers to a certain state of the art (structure, process status, coordination, installation, clearance and lubrication, etc.) rolling bearings, operating under actual status of the host, until the rolling surface fatigue can not meet the host bearing requirements, and (shaft seat) gross number of relative rotation of the outer ring - the total number of revolutions. When bearing pivots or more substantially constant is known, the fatigue life of the available total number of revolutions corresponding to the total number of operating hours indicated should also pay attention to:
(1) factors affecting NSK bearing fatigue life very much, all or can not be estimated by the standard test conditions be eliminated, which resulted in the actual fatigue life of NSK Bearings is very discrete, so the expression parameters bearing fatigue life rated life L10, the ISO recommendation R281 in the meaning of L10 clearly defined as follows:
"On a sufficiently large number of the same number of bearing rating life L10 with its revolutions (or the same number of hours used to indicate when the rotational speed, bearing 90% of the batch before fatigue spalling occurred meet or exceed this transfer number (or hours). "So far, the countries in the world to comply with the above requirements.
In the United States and other countries, but also with the concept of the median life. The median life expectancy LM refers to the lifetime value of a group of identical NSK Bearings, meaning that 50% of NSK bearings before fatigue spalling can reach or exceed the total number of revolutions, or working in a certain number of speed from time to time, the median life expectancy LM not the number of arithmetic mean bearing life. Usually median lifetime LM is about five times the rated life.
(2), the concept of rating life applies only to a sufficient number of number of bearing does not apply to individual bearings.
For example there are 40 sets of bearings their use shall be regarded as 6204 its rated life of 1000h and without fatigue failure, the remaining four sets may not 1000h appears bearing fatigue failure, the nominal fatigue life significance on behalf of these bearings in normal the life time can be expected to play its material potential. Therefore, in most cases, users select the bearing fatigue life calculation is still to make, and then check the actual failure categories, such as wear life check, take the results in a smaller value bearing life calculation.
|
|
