The discussion of bearing fault is the most effective method


Posted April 9, 2014 by iojhfn

Rolling bearing vibration diagnosis method. Rolling bearing fault has an obvious characteristic of frequency distribution, often in the low frequency and high frequency in two band performance

 
  Rolling bearing vibration diagnosis method. Rolling bearing fault has an obvious characteristic of frequency distribution, often in the low frequency and high frequency in two band performance, so the frequency analysis, can choose two frequencies are analyzed. Low frequency analysis of the frequency range for < 1000 hz, covered the characteristic frequency of bearing; High frequency analysis is generally 1000 ~ 20000 hz frequency range, the main INA Bearing Supplier http://www.fagbearings-hk.com/INA-Bearings-60.html the natural frequency and high order harmonic. In the early bearing faults, high frequency response is more obvious, but usually only distinguish the overall vibration conditions of rolling bearing, bearing a trouble-free and its severity conclusions can be; General can diagnose the fault component and low frequency analysis. Bearing vibration diagnosis, will use the two spectrum analysis, in order to confirm each other, more accurate conclusions.
  The vibration fault diagnosis example. Characteristic frequency calculation Y4-73-11 - nod type centrifugal induced draft fan for boiler power of 800 kw, the fan speed for n = 730 r/min, the blade is 12 slices, rolling bearing models for 3644, to analyze the vibration fault, first calculate the bearing fault characteristic frequency, bearing the relevant data for: roller diameter d = 60 mm; Section bearing diameter D = 340 mm; Rolling element number z = 16; Alpha = 0 ° pressure Angle. The above data into type, have bearing fault feature frequency components: each f1 = 114.54 Hz. F2 = 80.18 Hz; F3 = 33.4 Hz; F4 = 5 hz.
  Set up vibration diagnostic system to establish vibration testing system, on the one hand, to the same device for testing regularly, accumulate a large amount of data, the longitudinal comparison analysis; On the other hand the similar accumulate data for analysis, through long-term practice, especially for equipment failure accumulation of waveform and spectrum analysis, summarizes the general rule, is to identify equipment vibration type, accurate analysis of the basis of equipment failure. Of induced draft fan testing point set, generally in accordance with the motor of the lateral and medial, fan, fan inside the order of the factory of the lateral cooling set, set the horizontal radial as H, set the vertical radial as V, axial set to A, in this way, each induced draft fan is 12 Olympic as shown below.
  Through the induced draft fan vibration data on a regular basis, and through the analysis of the degradation, in October 2005, induced draft fan has been running smoothly, in August 2006 when testing, 4 h testing point vibration amplitude of the degradation tendency, excessive vibration in October 2006, induced draft fan F4A testing point vibration spectrum, the vibration amplitude of 13.05 MMS - 1, the vibration amplitude is now in the fault zone, marking the frequency of 33.39 Hz for rolling element bearing fault characteristic frequency f3, rolling element bearing problem exists, in the actual fault handling, the collapse of the equipment and found that the problem is on a rolling element has a about 2 mm deep, covers an area of 10 was pitting spot mark, bearing outer ring and inner ring has no obvious damage, bearing clearance requirements, if not found in time, bearing inner and outer circle will be scratched, bearing will be scrapped. Effective detection measures, to discover the degradation trend, accurate diagnosis of fault point is very important. When dealing with the problem, change after a roller rolling bearing, due to bearing problems induced draft fan 4 h testing point increase vibration fault is resolved.
  In each of the induced draft fan spectrum diagram, frequency of 12.17 Hz is working rotating speed frequency of peak (often called 1 XRPM), and the displacement spectrum to velocity spectrum and acceleration spectrum change process, 1 XRPM peak becomes smaller and smaller. In 1 XRPM displacement spectrum dominated, and in setting an induced draft fan and induced draft fan vibration testing point 4 h testing point vibration spectrum and wave type 1 in figure and degradation analysis spectral peak XRPM almost disappear. Thus, vibration analysis can see in spectrum extremely important bearing failure frequency, mainly depends on the selection of measuring amplitude type. As to the bearing fault frequency, clearly visible in the speed and acceleration spectra, around the characteristic frequency of equidistance side there is a frequency sideband, frequency the existence of sideband.
Conclusion. Effective application of spectrum analysis, not only can manage the degradation, determine the predicting maintenance equipment, also can accurately diagnose the potential fault location, is the ideal equipment degradation management methods, in use for a long time, with the accumulation and analysis of the testing data, the fault diagnosis of rolling bearing will be more mature.
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Issued By hjfthd
Website INA Bearing Supplier
Country Hong Kong SAR
Categories Business
Last Updated April 9, 2014