Generally,FAG bearing used to reach fatigue life if it is used in a right way. But there will be some unexpected prematurely damage, which have no ability to used anymore. This early damage, on the contrary with fatigue life, called the fault or accident quality use limit. These are usually caused by some substances invading from external and pay no attention to it when the installation，use and lubrication, or resulted from hot enough not well for the effect of the shaft, the shell, etc.About the damage status of FAG bearing, for example: FAG roller bearing rings raised edge card injury, these facts should view as a cause and take into considered, such as lubricant lack, not suitable, for the defects of soot structure,some substances invasion, bearing installation error, shaft buckling is too big, also can have these reasons superposition.
Therefore, it was hard to know that the real cause of the damage, if we only survey the FAG bearing damage. But, if we know the use of machinery, the using conditions of the bearing, the structure of the bearing, the situation before and after the accidents happens, combining bearing damage status with several reasons investigation, which can avoid the same accident happen again.