For a long time, bearings play an extremely important role in the whole industrial manufacturing field. Whether rolling bearing or sliding bearing or linear bearing, they are all widely used. However, it can not be ignored that as an excellent device, the bearings’ improper installations and usages will cause damage to themselves, reflecting the phenomenon that the machines have failed.
Take sliding bearing as an example. In regular use, the sliding bearing works stably, reliably, and noiseless. Under the condition of liquid lubrication, the sliding surface can be separated by lubricating oil without direct contact, which can significantly reduce the friction loss and surface wear, and the oil film also has specific vibration absorption capacity. But this kind of bearing often breaks down. The common faults are as follows:
1. Bearing journal surface scratch: there are iron cutting abrasive particles or black oxide particles in the Ferrograph, and there is tempering color on the metal surface.
2. Tile surface corrosion: spectrum analysis found that the concentration of non-ferrous elements was abnormal, many sub-micron wear particles of non-ferrous metal components appeared in the demography, and the water content and acid value of lubricating oil exceeded the standard.
Fretting wear on the back of tile: the spectrum analysis shows that the iron concentration is abnormal, there are many iron component submicron wear particles in the demography, and the water content and acid value of lubricating oil are strange.
After understanding these, how to check the bearing failure is the top priority. This test method is generally divided into three types:
First, check the vibration of bearing in operation. The vibration of bearing is very sensitive to the damage of bearing. Therefore, we can measure the vibration by using a special bearing vibration meter (frequency analyzer, etc.), and the specific abnormal situation can be inferred by frequency analysis. Because the measured value is different due to the installation position of the bearing sensor, it is necessary to analyze and compare the measured value of each machine in advance and then determine the judgment standard.
Second, check the sound condition of bearing. Because even if the bearing has a slight peeling and other damages, it will emit abnormal sound and irregular sound so that the sound detector can distinguish it. The sound detector is used to check the rolling sound size and sound quality of bearing in operation, to prevent it in advance.
Third, check the temperature of bearing. If the oil hole can be used to directly measure the temperature of the outer ring of bearing, it is more suitable. In general, the temperature of bearing can be inferred according to the temperature outside the bearing chamber. If the lubrication and installation are not appropriate, the temperature of bearing will rise sharply, and abnormally high temperatures will occur. At this time, the operation must be stopped, and necessary preventive measures shall be taken.
The bearing fault is inevitable, but if the fault location and the cause can be detected in time, it may be able to avoid bearing replacement in time and extend its service life. All in all, the above three inspection methods are applicable to almost all brands of bearings, including NSK bearing, FAG bearing, SKF bearing, etc.