Generally, the bearing is associated with the shaft, the inner shell of the bearing is mounted on the shaft, and the outer shell of the bearing is mounted on the housing. When the inner cover is attached to the shaft and rotates, the inner cover and the shaft are in close contact, and the bearing cover and the bearing body are in close contact. On the contrary, when the bearing body and the bearing shell are rotated together, the bearing shell and the bearing body are close together, and the clearance between the bearing shell and the shaft is tight. paste. Running lap problems often occur during operation and need to be analyzed and processed. Otherwise, there will be accidents, causing great losses.
Reasons for bearing running circle:
Bearing running circle is a common fault, and there are many reasons for running circle.
1. Improper cooperation
The running bearing generates heat, and there is a temperature difference between the shaft and the inner cylinder, the outer cylinder and the bearing. These temperature differences will cause the looseness of the fitting to change. When the inner cylinder of the fitted bearing is larger than the outer diameter of the shaft, it will follow Wear and tear over time, running laps are inevitable, more heat is generated, and the temperature of the bearing will rise. Due to the expansion of the bearing body, when the bearing clearance disappears, the bearing inner cylinder becomes one body. When the shaft rotates, the bearing outer cylinder The rotating motion on the bearing body generates a lot of heat, and an accident occurs, and the inner cylinder of the bearing body is worn out. This is the process caused by the poor tension caused by the temperature difference.
2. Running laps caused by vibration
The greater the vibration of the equipment, the greater the load on the bearing and the bearing, the shaft will be knocked during operation, and the shaft will be stretched soon and the journal will become thinner. This destroys the original tightness of the fit and creates conditions for fretting, heating, and running. The journal becomes thinner and the holes in the bearing are worn out.
3. Poor lubrication
In the case of poor lubrication, the friction generates a lot of heat, the temperature difference between the sleeve and the bearing body in the bearing is large, the previous matching size is destroyed, and the bearing journal and bearing body are worn.
4. Improper selection of lubricating oil and many impurities
When the grease hardness is high or there are foreign objects, it will have a blocking effect on the bearing rolling elements, preventing the rolling elements from rotating and generating frictional heat. At the same time, it promotes the selection of the bearing inner sleeve and produces wear. When the resistance is large, the resistance can overcome the bearing sleeve and shaft The friction force prevents the shaft and sleeve from sliding, sliding and wearing
5. Improper installation
Poor installation mainly means that the heating temperature of the bearing is too high. After the bearing expands, the size cannot be restored. The free end bearing clearance of the shaft is insufficient, resulting in the bearing side friction and heating of the bearing, the bearing, and the bearing are not cleaned, which will block the joint of the divided shells. Squeeze the bearing, the bearing is partially caught
6. Long-term vibration and knocking will cause the shaft side to fall off due to fatigue
When the chips are discharged, loosening will inevitably occur, resulting in bearing running circles.
7. Bearing failure.
Bearings that move for a long time will cause fatigue and pitting on the track, and the fallen debris will produce a weir effect. When heating, a temperature difference will occur, and a lap phenomenon will occur.
