yes the are equally spaced too by the running speed and the difference between the marked A and Red X at is about half the running speed but my question is
how could this be a early warning, By early warning, I simply mean, a signal early enough to possibly schedule a shutdown rather than running until it became obvious that there was a worsening looseness problem, when the 1/2x or even 1/3x energy has moved down the frequency scale until they (1/2x or 1/3x) are showing between the real 1x and 2x and 3x harmonics of running speed. Even in this data, the 1/2x was already down to the 6th, 7th, 8th, 9th, etc.
ok,,we can tell a question here.. when should i call that a bearing change is a must action.at which point this is what i meant when 1/2x is visible this is what i understood am i right ?
harmonic of 1x running speed. Earlier detection might have been possible with Peakvue data taken in the other two directions (Vertical and Axial). Or by simply looking at the velocity data displayed in Gs without the vertical "autoscale" function activated. but the actual situation is that a worn shaft under bearing about 0.2 mm I think I understand what you are saying about "the actual situation", but correct me if I am wrong. I think you mean that at this point in time, when this data was taken, there was already 0.2 mm wear in the shaft.
yes this is exactly what i meant as the measurement was conducted and wear was already exhibited in shaft
If this is what you are saying (or implying), my guess is that there has been a signal similar to this one which we are discussing and may have possibly been overlooked due to the low amplitudes, which (the amplitudes) may have been even somewhat lower than this data.
the second question what is the reference that i should call it a looseness the "reference" I would use is the fact that there should not be a 1/2x in an "all around" good bearing as the G level is low, IMO, the Gs are possibly going to be "low" since there is a low or small amount of energy being transmitted to the bearing housing, since it (the (energy or amplitude) has to travel from the shaft and inner ring slippage, through the inner ring, through the balls or rollers, through the outer race and through the bearing housing before it gets to the transducer. There is a theory that acceleration does not travel very far from the source. and why did you choosed this band from 6000 to 11000 cpm at a previous comment I chose this particular band because it appeared to be the area with the most energy within the Fmax data available at the time and even in velocity data there appeared to be something "strange" there. There is nothing magical about choosing this particular area(6K to 11K). There also appeared to be some of the same type data nearly the full length of your spectrum. I guess the "magic" might be understanding that Gs display better in the higher frequency range and not always using the vertical "autoscale" function, and not relying on velocity data too much in the higher frequency area. Sometimes many important things can not be seen and are sometimes never seen until they progress down into the lower frequency range, if using only velocity data. I am not saying you are doing this. Just stating what I do.
i always rely on peakVue data depending on 1Khz and 2Khz filters but what was mentioned that the peakvue is always tricky at the bearings which is submerged in oil or been splashed by oil rather than the bearings running in grease.
This seems to be part of the theory of the Peakvue data, IMO. The wanting to know, " What is happening in the higher frequency range." And this sort of falls back to our short discussion on directional positioning for taking Peakvue data.
i will try the peakvue in axial direction today in bearings i suspect them.
i also use the Autocorrelate function at the timewave form to show the periodic impact this is also very effective i have many cases detected by the auto correlation.
Remember that all I have said here is solely my own opinion based on experience and I could be totally wrong.
Thanks and Have a Great Day,