How to determine whether the bearing can be used again?2018-09-17 17:21:49

"When the equipment is regularly serviced, the operation checks and the peripheral parts are replaced, it is important to investigate and record the bearing appearance when the bearings are removed for re-use." In order to understand and investigate the remaining amount of lubricant, after sampling, the bearings should be cleaned well. ”

Check the condition of raceway surface, rolling surface and mating surface, as well as the wear condition of the cage, such as damage and abnormal condition.

In addition, considering the degree of bearing damage, machine performance, importance, operating conditions, inspection cycle, and so on, to determine whether the bearing can be reused or replaced. If the bearing is found to be damaged or abnormal, identify the cause and formulate countermeasures. If there are several defects, the bearings can no longer be used, need to replace the new bearings.

A. Inner and outer rings, rolling bodies, cages any of which have cracks and fragments.

B. Inner and outer rings, rolling element any one of which has a stripping.

C. The raceway surface, the flange, the rolling body has the significant card injury.

D. The wear of the cage is serious or the rivet is loose badly.

E. Raceway surface, rolling body rust and have scars.

F. There are significant indentation and scratches on the rolling surface and on the rolling body.

G. There is creep on the inner ring diameter or outer diameter.

H. Overheating discoloration is severe.

I. Grease seal bearing sealing ring and dust cover damaged seriously.

In-operation Inspection and fault handling

The inspection item in operation has the rolling sound, vibration, temperature and lubricating state of the bearing, and the specific situation is as follows:

1. Rolling sound of bearings

Using a sound detector to check the rolling sound and sound quality of the bearing in operation, even if the bearing has a slight peeling and other damage, it will emit abnormal sound and irregular sound, which can be distinguished by acoustic detector.

2. Vibration of the bearing

Bearing vibration is sensitive to bearing damage, such as flaking, indentation, rust, cracks, abrasion, etc. will be reflected in the bearing vibration measurement, so, through the use of special bearing vibration measuring device (frequency analyzer, etc.) can measure the size of the vibration, through the frequency to infer the specific situation of the anomaly. The measured values are different depending on the conditions of use of the bearings or the location of the sensor, so it is necessary to determine the judging criteria before analyzing and comparing the measured value of each machine.

3. Temperature of the bearing

Bearing temperature, generally outside the bearing chamber temperature can be inferred, if the use of oil hole can directly measure the bearing outer ring temperature, it is more appropriate. Normally, the temperature of the bearing starts to rise slowly as the operation begins, reaching a steady state after 1-2 hours. The normal temperature of the bearing is different depending on the heat capacity, heat dissipation, speed and load of the machine. If the lubrication, the installation of the appropriate, then the bearing temperature will be sharp rise, will appear abnormally high temperature, then must stop operation, take the necessary precautions. The use of thermal sensor can monitor the operating temperature of the bearing at any time, and to realize the temperature exceeding the specified value of automatic alarm or stop to prevent the occurrence of shaft accidents.