A typical bearing faults of rotating equipment

A typical bearing fault 2019 - of rotating equipment 12 - 13 a overview, equipment supply fan is the key to the boiler equipment, per boiler configuration two blowers, boiler operation, two blower operation at the same time, no backup device. If the shutdown due to a blower fault, boiler load will be reduced to 50% of capacity, in order to maintain boiler operation, must be cast oil gun, will cost a lot of diesel oil, and other company unit load fluctuations. This unit is a cantilever type centrifugal fan, blower structure model SFG22D - C4A, medium is air, power 800 kw, rated speed 990 RPM. This unit not online most of the rotating equipment testing equipment, the current diagnostic instrument using BH550 comprehensive analysis artificial vibration, temperature data. Second, the fault description on February 1, 2019, no. 4 furnace blower coupling b bearing is intermittent sound, use BH550 detection, found that the vibration intensity increased slightly ( Before February 1, 3 h vibration velocity in 2. About 5 mm/s, February 1, increased to 3. 2mm/s） , vibration acceleration and govemment values increase, 3Ha：26mm/s² ,3 hgie: 10。 96). , 3 h, 3 v except double frequency in the spectrum, there are multiple frequency division, the frequency distribution is messy, and multiple frequency amplitude is greater than 1 frequency doubling, a preliminary judge bearing roller or cage has a problem. Three, failure analysis diagram from the trend of the 3 h, the vibration velocity RMS increased to 3. 57mm/s（ FIG. 2) For large fan, the vibration value is still in the scope of the good. In the spectrum, Figure 4) , double frequency is not the main component, there are a lot of high frequency, and distribution is messy. On January 28, vibration acceleration oscillogram of 3 h ( FIG. 5) And amplitude in & plusmn; Less than 20. On February 1, 3 h vibration acceleration oscillogram ( Figure 6) And amplitude in & plusmn; Within 60, energy is increased to 3 times, and the waveform linear density increases, the mean energy and frequency increased significantly. Comparing before and after the envelope, on January 28th envelope spectrum diagram ( As shown in figure 7) , bearing the characteristics of the various components are not found in frequency on the peak, and the low amplitude, at 0. 5 or less. Envelope waveform diagram ( As shown in figure 8) Just more than 4, highest amplitude. On February 1, envelope spectrum diagram ( As shown in figure 9) , bearing parts obviously increase the characteristic frequency amplitude and waveform envelope of sheet value increases to more than 15 times ( As shown in figure 10) 。 In a lot of high frequency spectrum diagram according to the vibration intensity, and frequency, bearing may be the impact of the high frequency; Diagram, the vibration acceleration waveform amplitude increase to 3 times, and density increase, show that the impact energy increases. Envelope spectrum diagram, the characteristics of the bearing components frequency amplitude increases, the waveform diagram is about 15 times. Use listen to pin coupling side bearing, there is a clear, intermittent sound. Above comprehensive analysis, the conclusion is probably coupling lateral bearing roller or maintains there is a problem, need immediate attention. Four, fault verification on February 2, 2019, down, found that the blower coupling lateral surface of a rolling element bearing detachment ( Figure 11. ) Hemp pit, bearing inner ring raceway, Figure 12) , also have the bearing outer ring raceway pockmark ( Figure 13) , impeller side bearing in good condition, the coupling side bearing for replacement. On February 2, bearing replacement, blower, the good direction vibration indexes is achieved, Figure 14) 。 After repair of 3 h speed spectrum ( Figure 15) , clutter disappear at high frequency, a frequency of 390 hz is the inherent frequency, source is unknown. After repair of 3 h acceleration waveform diagram ( Figure 16) And amplitude to & plusmn; Within 20, the impact energy is reduced, and the waveform figure density decreased. Envelope spectrum map values to a maximum 0. 4, corrugated sheet value & le; 6. Through the equipment fault judgment, it is concluded that the following experience: check the vibration data, cannot be confined to only look at excessive amplitude of vibration intensity, should also be comprehensive vibration acceleration, the change of the govemment to overall judgment equipment is normal. At the same time, the traditional means can not discard, such as using the needle, for an experienced operation and maintenance personnel, listen to the needle can be clear and intuitive found defective equipment, the maintenance is checking with listen to needle devices have obvious different sound, coupled with BH550 accurate judgment of the bearing fault, and quickly replaced the bearing, avoid the equipment accident expanding. （ Source: bower letter Beijing science and technology co. , LTD. )