Second, the rolling bearing fault evolution

Rolling bearing in the process of its use will exhibit strong regularity, and the repeatability is very good. Normal high quality bearing, at the beginning of the use of vibration and noise are relatively small, but please some scattered amplitude is smaller, may be due to some defects in the manufacturing process, such as surface caused by burrs, etc. When bearing run after period of time, maintain a certain level of vibration and noise, is a single, only one or two times. Rarely appear more than three feed power frequency spectrum, bearing condition is very stable, steady working period, as shown in figure 1 9. Figure 1 - 9 in dynamic bearing stable job of maintaining a late run to bearing use, and the vibration waveform and spectrum of bearing vibration sound began to increase, sometimes a different sound, but the change of vibration increase is relatively slow, the bearing began to fail. Generally the dynamic evolution of bearing fault is divided into four stages, as shown in figure 1 10. Began to show faint signs of the failure of the first stage, that is, bearing stage, this time the total temperature, noise, vibration velocity and frequency spectrum are normal, but the peak signs, total energy and spectrum reflect the beginning of the bearing fault. When the real bearing failure frequency in ultrasonic period of approximately 20 - 60 KHZ range. Increases slightly in the second stage, the temperature is normal, noise, vibration dynamic speed increases slightly, total vibration spectrum change is not obvious, the catastrophic bad but rush energy has a big increase, spectrum is also more prominent. At this time of the bearing fault frequency in approximately 500 - D bearing initial paragraph (2) move slightly bearing fault phase 2 KHZ range. (3) in dynamic macroscopic bearing fault phase (1) the third stage, the temperature is slightly higher, available ears hear noise (1) dynamic bearing failure last phase, the increase of total vibration velocity has a big, harmonic frequency and the vibration velocity (2) can be clearly seen on the bearing fault frequency and its harmonics when reading and sideband, the other on the vibration velocity spectrum 'horizon' noise significantly increased, peak total energy compared to the second stage become figure 1 - 10 greater development process, the typical faults accur spectrum is also more prominent. At this time of the bearing fault frequency rate appeared in about 0 1 KHZ range. Suggest that late in the third stage to replace its bearing, this time should have been to the naked eye can see the rolling bearing fault characteristics such as wear and tear. The fourth stage, the temperature rise obviously, noise intensity change obviously, the total amount of vibration velocity and vibration displacement are increased, the vibration velocity spectrum on the bearing fault frequency began to disappear, is more random broadband high frequency 'total noise horizon replace: peak energy increases rapidly, and some unstable changes may occur. Must not be allowed bearing in the fourth phase of fault development, operation or catastrophic damage may occur. According to the results, in general, if the service life of the bearing of the whole is Lm, so since bearing installation for people when using meter, before it's 80% L = life period, bearing is all normal.