Damage state: the so-called crack refers to the rolling wheel or rolling body cracks. If used again, cracks will also be included in the development of the crack.
Reason: over large capacity. Excessive load, impact load. Peeling off has developed. Heating and fretting wear due to contact between the raceway and the mounting member. Fever due to creep. The cone angle of the tapered shaft is not good. The cylindricity of the shaft is bad. The fillet radius of the shaft step is larger than that of the bearing, resulting in interference with the chamfering of the bearing.
Measure: appropriate amount of interference. Check load conditions. Improved installation method. The shape of the shaft should be appropriate.