The fracture phenomenon of rolling bearing rings is caused by raceway fatigue: usually a large area of u200bu200braceway fatigue damage; often stepped (sometimes linear) in the fracture area, see Figure 63 Reason: further developed fatigue Remedy for damage: see Section 3.3.2.1 Fractures 3.3.3.2 Axial primary cracks in the inner ring and through cracks in the inner ring: The ferrule is partially or entirely fractured in the axial direction. Slightly rounded fracture: Indicates that a fracture occurred during operation and continues to operate. The sharp fracture indicates that it was created during disassembly. After long-term operation of a bearing with cracks, the sharp fracture edge will partially peel off, see Figure 64. Causes: Bearing slipping Raceway breakage Inner ring running on shaft Inappropriate lubrication Too tight fit on shaft Shaft surface grooves Insufficient roundness Scratching with peripheral components. Remedial measures: Improve lubrication (additives, increase the amount of lubricating oil) Remedial measures for raceway damage Selection of suitable fit Avoid scratching of surrounding components Provide better mating surface Special heat treatment of rings 40 pairs of removed bearings Evaluation of running characteristics and damage rolling contact mode 63: failure caused by axial fracture of outer ring of deep groove ball bearing 64: axial through crack of inner ring of spherical roller bearing Circumferential fracture phenomenon of outer ring: usually cracks develop in the circumferential direction. Often breaks into several pieces. Under axial loads, these fractures often occur in regions that deviate from the middle of the raceway. Often fatigue is the cause of destruction. The outer surface of the outer ring generally exhibits an abnormal load-bearing form, see Figure 65. Cause: Insufficient support of the ring matched with the housing Remedy: Improve support.