The so-called fracture refers to a small part of the fracture due to the impact or excessive load exerted by the NTN bearing on the retaining edge of the raceway wheel or the local part of the roller angle. The reason for this is that the bearing was hit during installation. Excessive load. Poor use such as falling.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
Corresponding measures shall be taken to improve the installation method (hot installation and appropriate tool clamp). Correct load conditions. The cylindrical roller bearing is installed in place to support the retaining edge.
First, the reasonable design and advanced nature of the structure will lead to longer NTN bearing life. The manufacturing of bearings generally goes through multiple processing processes such as forging, heat treatment, turning, grinding and assembly. The rationality, advanced nature and stability of all the processing technologies will also affect the life of bearings. The heat treatment and grinding processes that affect the quality of finished bearings are often more directly related to the failure of cylindrical roller bearings. In recent years, the research on the metamorphic layer on the working surface of bearing shows that the grinding process is closely related to the surface quality of bearing.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
The metallurgical quality of NTN bearing material was once the main factor affecting the early failure of rolling bearing. With the progress of Metallurgical Technology (such as vacuum degassing of bearing steel), the quality of raw materials has been improved. The proportion of raw material quality factor in the failure analysis of cylindrical roller bearing has decreased significantly, but it is still one of the main influencing factors of bearing failure. Proper material selection is still a factor that must be considered in bearing failure analysis.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
The main task of bearing failure analysis is to find out the main factors causing NTN bearing failure according to a large number of background materials, analysis data and failure forms, so as to put forward targeted improvement measures, prolong the service life of the bearing and avoid sudden early failure of cylindrical roller bearing.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
The second may be excessive load (excessive preloading). Excessive speed. The clearance is too small. Intrusion of water or other foreign matters. If neither of the above two cases is true, the accuracy of the shaft and bearing housing is poor and the deflection of the shaft is large. Seeing this, I think everyone wants to know the solution. First of all, we should study the lubricant and lubrication method, select the right lubricant for cylindrical roller bearing and its dosage, and correct the selection of NTN bearing. Study the fit, bearing clearance and preloading, and improve the sealing device. Check the accuracy of the shaft and bearing housing.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
During the operation of the mechanism, the part where the rod end joint bearing is installed is allowed to have a certain temperature. When touching the mechanism shell by hand, it is normal to feel that it is not hot. Otherwise, it indicates that the temperature of Koyo bearing is too high.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
The reasons for high bearing temperature include: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; The mechanism assembly is too tight (insufficient clearance); Koyo bearing assembly is too tight; The bearing race rotates on the shaft or in the shell; Excessive load; Broken joint bearing cage or rolling element at rod end, etc.Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
The rolling bearing is allowed to make slight running noise during operation. If the noise is too loud or there is abnormal noise or impact sound, it indicates that the bearing is faulty.
1. Check whether the actual load and speed of Koyo bearing are different from the original one, and whether the bearing selection is correct;Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
2. Understand the abnormal phenomena during and near damage, especially the appearance and evolution of noise and heating; Pay attention to check the power supply and the adjacent mechanical elements of the rod end joint bearing for abnormalities during this period. Analyze the type of noise, the level of tone, the interference rhythm of frequency: pay attention to when the temperature suddenly increases, and write down the power supply and other parts;Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
3. Find out the configuration and matching characteristics of the rod end joint bearing in the main engine, judge whether it is properly configured, and write down the position of the ferrule relative to the shell and relative to the load direction;
4. Manually rotate the shaft and the damaged Koyo bearing for several turns to experience the heaviness of operation, and then push the shaft back and forth several times along the axial direction to experience the tightness of the shaft along the axial direction. If necessary, measure the deflection of the shaft;Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
5. Check the position of the bearing and find out the lubrication; Check whether the lubricant brand and sealing method are wrong. Pay attention to whether the temperature of Koyo bearing exceeds the temperature limit of the lubricant used in case of temperature rise. Focus on checking the oil level, whether the sealing clearance is oil and grease leakage, and whether moisture, dust or other foreign objects have invaded the rod end joint bearing, and whether the oil supply system is faulty
6. Check whether there are vibration sources that affect the bearing. Debris or particle source, water source or fluid pollution source, current source that can flow through rod end joint bearing;Three Factors to Deal With Burn Failure of NTN Cylindrical Roller Bearing
7. According to the inspection, it can be used as a basis to judge whether the damage of the bearing is due to fretting corrosion, wear, corrosion or electric corrosion.
During the disassembly and inspection of Koyo bearing, the failure and damage cause of rod end joint bearing can be judged according to the damage of bearing.