The length of time from the beginning of the bearing to the appearance of the first material fatigue point is related to the number of revolutions, load size, lubrication and cleanliness of the bearing during this period. Fatigue is the result of the periodic appearance of shear stress under the loaded surface. After a period of time, tiny cracks will be initiated and then gradually extend to the surface. When the rolling element passes through the small area formed by these cracks, some cracks begin to fall off, forming the so-called peeling phenomenon. As the peeling continues to expand, the bearing is damaged and cannot be used. Initially occurs under the surface. Although the initial peeling is usually very slight, as the stress increases and cracks increase, the peeling area spreads. This process usually lasts for a long time with obvious vibration and noise. Therefore, there should be enough time to replace it before it is broken. The main reason for the damage is the force traces of the bearing. Usually, after the bearing has been in operation for a period of time, there will be obvious stress traces on the working surface. Not all traces indicate that the bearing is broken. The bearing is in normal condition. Use will also leave traces of stress.

The bearing runs under load, and the contact surface of its raceway is dull and black in appearance. But this does not mean it is abrasion, and it has nothing to do with life. This black trace constitutes the force trace of the bearing. The appearance of this trace varies with its operation and load conditions. Careful inspection can help us determine whether the bearing is operating under normal conditions.

Radial bearings, ball bearings, spherical surfaces, and double-row balls only bear radial force and can bear a small amount of axial load. Often the damage is caused by excessive axial force. Internal and external stress marks: the inner ring rotates, the outer ring is fixed and the outer ring rotates, the inner and the inner ring is fixed and the inner and outer rings are fixed and the inner and outer rings are fixed. One-way radial load: two cases, one Directional axial load: the inner ring or outer ring rotates. Force traces, deviate from one side Inside and outside Force traces ⑶, a combination of unidirectional radial load and axial load. Internal and external force traces The inner and outer rings rotate, the outer ring is fixed, the inner ring and the outer ring ⑷, the radial load rotates synchronously with the inner ring, the outer ring fixed radial load rotates synchronously with the outer ring, the inner ring fixes the outer ring rotates, and the inner ring fixes the friction loss of the bearing Almost all inside the bearing becomes heat, which causes the bearing temperature to rise. The heat generated by friction torque can be expressed by the following formula: Q=0.105*10 Q=0.105*10 --66 MN MN