“During the regular maintenance, operation inspection and replacement of peripheral parts of the equipment, judge whether the disassembled bearing can be used again. Be sure to carefully investigate and record the appearance of the bearing. In order to find out and investigate the remaining amount of lubricant, the bearing shall be better cleaned after sampling.”
Check the condition of raceway surface, rolling surface and mating surface, as well as the wear state of cage for damage and abnormalities.
In addition, after considering the degree of bearing damage, machine performance, importance, operating conditions and inspection cycle, we can decide whether the bearing can be reused or replaced. If the bearing is damaged or abnormal, find out the cause and formulate countermeasures. If there are the following defects, the NTN bearing can no longer be used, and a new bearing needs to be replaced.
The inspection items during operation include rolling sound, vibration, temperature, lubrication status, etc. the specific conditions are as follows:
The sound detector is used to check the rolling sound and sound quality of the running bearing. Even if the bearing has slight peeling and other damage, it will produce abnormal sound and irregular sound, which can be distinguished by the sound detector.
Bearing vibration is very sensitive to bearing damage, such as peeling, indentation, corrosion, crack and wear, which will be reflected in bearing vibration measurement, By using a special bearing vibration fag bearing dynamic measuring device (frequency analyzer, etc.), the magnitude of vibration can be measured, and the specific situation of abnormality can be inferred from the frequency. The measured values vary according to the service conditions of the bearing or the installation position of the sensor, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard.
Usually, the temperature of the bearing starts to rise slowly with 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 appropriate, the bearing temperature will rise sharply and abnormal high temperature will occur. At this time, the operation must be stopped and necessary preventive measures must be taken. The 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, so as to prevent the occurrence of combustion shaft accident.