Replacement criteria for angular contact bearings

Bearings are used only after they have gone through strict forging, heat treatment, grinding, assembly and other processes and passed the inspection. However, bearings are consumables after all. No matter how good the product quality is, they have a service life. Once a certain situation occurs that affects the performance of the bearing and the operation of the equipment, it needs to be replaced in time. So do you know when Wafangdian bearings need to be replaced?
1.Fatigue failure
Generally, the operation time of bearings is 2-3 years. If the use time exceeds the rated life, you can consider replacing them to avoid affecting the performance of the equipment. Because when the bearing is running, the rolling element and the inner and outer rings of the bearing will rub against each other, and the retainer and the rolling element will also rub against each other, even with the protection of lubricating oil. Then long-term friction loss may cause wear on the bearing surface, thereby affecting the performance of the bearing, and should be replaced in time.
2. Wear failure
In addition to natural wear, there is another type of wear during the use of bearings, which is abnormal wear. This may be caused by the influence of the external environment during the operation of the bearing. Metal powder, oxides and other hard particles invade the bearing, causing severe wear, that is, friction corrosion. A pit with the same pitch as the steel ball is formed on the ring. When the wear is large, the bearing will produce clearance noise, increase vibration, and affect the bearing performance.
3. Corrosion failure
The corrosion of the bearing surface is divided into three types: chemical corrosion, electrical corrosion and micro-vibration corrosion. The pitting of the surface by water, acid or cold lubricant and current on the bearing ring in the seat hole or on the shaft diameter will cause corrosion to the bearing surface. Then the corrosion expands and peels off to form a depression, affecting the bearing performance.
4. Fracture failure
When the bearing parts are working, the load is too large, the speed is too high, the lubrication is poor or the assembly is poor, and the thermal stress is too large, resulting in fractures and cracks on the bearing surface. It is a manifestation of serious failure and needs to be replaced in time.
5. Roller deformation
The contact between the rolling element and the raceway of the bearing produces plastic deformation. When the load is too large, pits will appear. Of course, it may also be due to improper assembly, resulting in local depressions and indentations on the raceway. At this time, the overall performance of the bearing is greatly affected and needs to be replaced in time.
6. Gluing failure
When the metal of one surface of the two contacting surfaces of the bearing adheres to the other surface, this phenomenon is called gluing. If the rolling element is stuck on the cage or insufficiently lubricated, it will cause excessive friction heat due to excessive speed, and then the cage material will easily stick to the roller to form gluing, which is a spiral stain. Of course, it may also be due to the small gap, the rolling element and the inner and outer rings squeezed due to thermal expansion, resulting in gluing and peeling during the rolling of the bearing.
7. Other injuries
There are many situations in which Wafangdian bearings need to be replaced. To sum up, the bearings have external injuries that cannot be restored through repairs, and the performance of the bearings during operation is affected, and the operating accuracy required by the equipment cannot be achieved. At this time, they need to be replaced in time. Other external injuries include but are not limited to rust corrosion, electrolytic melting, indentation, wear, deformation, etc., all of which need to be replaced in time.