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Can the removed bearing be used for the second time?

Update:28-12-2020
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Regardless of the type of equipment, it must be regular […]

Regardless of the type of equipment, it must be regularly overhauled and inspected. Many people have questions. Can the removed bearings still be used?

When the equipment is regularly overhauled, operating inspection and peripheral parts replacement, it is necessary to carefully investigate and record the appearance of the bearing to determine whether the disassembled bearing can be used again. In order to find out and investigate the remaining amount of lubricant, after sampling, the bearing should be cleaned well.

Check the condition of the raceway surface, the rolling surface and the mating surface, and the wear state of the cage for damage and abnormal conditions. Furthermore, after considering the degree of bearing damage, machine performance, importance, operating conditions, inspection period, etc., the bearing can be used or replaced again. If damage or abnormality of the bearing is found, find out the cause and formulate countermeasures. If there are the following defects, the bearing can no longer be used, and a new bearing needs to be replaced.

1) There are cracks and fragments in any of the inner and outer rings, rolling elements, and cage.
2) Any one of the inner and outer rings and rolling elements has peeled off.
3) The raceway surface, ribs, and rolling elements are significantly stuck.
4) The cage is severely worn or the rivets are loose.
5) The raceway surface and rolling elements are rusty and scratched.
6) There are significant indentations and marks on the rolling surface and rolling elements.
7) There is creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.
8) Discoloration is severe due to overheating.
9) The seal ring and dust cover of the grease-sealed bearing are seriously damaged.

 

 

The inspection items during operation include the rolling sound, vibration, temperature, lubrication state of the bearing, etc. The details are as follows:

1. The rolling sound of the bearing   
The sound meter is used to check the size and sound quality of the rolling sound of the bearing in operation. Even if the bearing is slightly damaged such as peeling, it will emit abnormal and irregular sounds, which can be distinguished by the sound meter.

2. Vibration of the bearing  

Bearing vibration is very sensitive to bearing damage, such as peeling, indentation, rust, cracks, wear, etc. will be reflected in the bearing vibration measurement, so the vibration can be measured by using a special bearing vibration measuring device (frequency analyzer, etc.) The size of the abnormality is inferred from the frequency. The measured value is different due to the use condition of the bearing or the installation position of the sensor, so it is necessary to analyze and compare the measured value of each machine in advance to determine the judgment standard.

3. The temperature of the bearing

Generally, the temperature of the bearing slowly rises with the operation, and reaches a stable state after 1-2 hours. The normal temperature of the bearing varies with the heat capacity, heat dissipation, speed and load of the machine. If the lubrication and installation parts are proper, the bearing temperature will rise sharply and abnormally high temperature will occur. At this time, the operation must be stopped and necessary precautions must be taken. The use of a thermal sensor can monitor the working temperature of the bearing at any time, and automatically alarm or stop when the temperature exceeds the specified value to prevent the occurrence of combustion shaft accidents.
Modern machinery and equipment are almost all equipment that requires a lot of capital. The purchase, maintenance and use of equipment are very expensive. The economic benefits of equipment management are urgently needed to reduce the physical wear of equipment and reduce equipment through daily maintenance and maintenance of equipment. Maintenance costs and other abnormal expenses during the life cycle.

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