Source:未知Author:HONBbearing07 Addtime:2021-05-31 10:39 Click:
Six major bearing faults are fatal!
Bearing fatigue is characterized by spalling of bearing raceways. This is because the particle strength of the bearing steel is reduced, causing the particles to peel off from the raceway. The bearing surface after peeling is rough, which will generate noise and vibration.
When the bearing reaches its expected life under normal load and working conditions, normal fatigue damage will occur. This type of damage is predictable, it is due to metal damage caused by the continuous action of the load.
After the bearing hole in the transmission is re-inserted, if the size of the bearing hole is too small or out of round, early fatigue damage may occur. Particular care should also be taken when reboring holes in the housing. After the holes on the shell are boring, it will cause the installation error of the shaft, which will also cause the early fatigue damage of the bearing. Therefore, the accuracy of the boring equipment should be relatively high.
2) Poor lubrication
The characteristics of bearing damage caused by poor lubrication are: bearing parts discoloration and raceway peeling, or cage damage. The reason for bearing damage is not only because the oil level is too low, but also because the lubricating oil contains impurities, improper grade, and the mixing of lubricating oils of different brands.
In order to prevent this kind of damage, the transmission should maintain a proper oil level, use the recommended lubricant brand and grade, and change the oil regularly.
Indentation refers to a small gap on the shoulder or bottom of the bearing raceway. Second, it may be caused by improper installation or removal of the bearing. If it is supported on one seat ring of the bearing, knocking or pressing the other seat ring will cause indentation. When hitting the bearing with a hammer or chisel, in addition to indentation, it may also cause damage to the dust cover, cage and retaining ring. The above-mentioned damage can be avoided by using correct tools such as pull wheels.
4) Fretting wear
Due to the vibration, the machining strips on the bearing hole will be rolled out on the outer ring of the bearing. This effect is called fretting wear. Bearings subjected to fretting wear are often mistakenly diagnosed as the above-mentioned streaks caused by the bearing rotating in the hole. The outer ring of the bearing rotates in the hole only under extreme conditions.
5) Contamination damage
Contamination and damage to the bearing are caused by dirt entering the transmission housing or impurities entering the bearing during maintenance and storage.
Contamination and damage of bearings are mostly manifested as raceways: nicks, scratches or pitting on the balls or rollers, and rust or corrosion of bearing parts. In addition, if the lubricating oil contains very fine particles (such as abrasive powder), or the use of extreme pressure lubricating oil with high activity, the bearing parts will also be ground.
When the transmission is normally ventilated, impurities often enter the transmission. Therefore, it is necessary to replace the lubricating oil of the transmission according to the specified period to reduce the pollution damage of the bearing.
6) The inner and outer circles are different
If the input shaft of the transmission is misaligned with the guide bearing hole in the flywheel when the transmission is installed, the positioning bearing on the input shaft may be out of concentricity between the inner and outer rings. At this time, the roller cage and the dust cover may be damaged.
When looking for the cause of disagreement, first check the coaxiality of the clutch housing and mounting surface with the guide bearing. At the same time, check whether there is any debris mixed in and whether the mounting position is correct.