while i'v been monitoring a clay crusher in a cement factory...the vibration values and trends show problem
spectra shows peaks at 6150 cpm which is close to 2x line frequency "line frequency is 50 HZ in my country"
although its so much closer to BPFO " outer race defect frequency"and it has harmonics...it evan has sidebands
i'd just recomend to change the bearing in normal cases....
but as u see in da spectra...1stable da spectra didnt changed alot for like 2 years or something.....and it has really low G's and low impact....beside no spike energy or high frequency noice.......and agin the spectrum figuer doesnt change that much vs the time....
anybody has any ideas about this problem
i'v attached some spectra and i really wana hear ur opinions

clay_crusher_case_study__march.doc (70 Kb, 78 downloads) spectra in word file

Hello Egypt,
To me, the waveform really looks like a gear problem, possibly misalignment with translation problem??? Any chance it comes close to gear mesh?
Best regard, Marcel

The 2x LF that I have seen usually is much close than that.
What are the sidebands around the 1st peak on the last page. If you have a newer version of software you can autocorrelate the waveform and put it in circular plot. This will do a great job of identifying an inner race fault if that is the case here.

quote:

Originally posted by Marcel B:
Hello Egypt,
To me, the waveform really looks like a gear problem, possibly misalignment with translation problem??? Any chance it comes close to gear mesh?
Best regard, Marcel

well... its belt drive....so there is no gearbox out there....means no gearmesh

quote:

Originally posted by Vibeguy2004:
The 2x LF that I have seen usually is much close than that.
What are the sidebands around the 1st peak on the last page. If you have a newer version of software you can autocorrelate the waveform and put it in circular plot. This will do a great job of identifying an inner race fault if that is the case here.

but arnt u with me that if its bearing fault....the spectra would change over the years....with bearing fult stages changing...
beside as i said.....there is no noise floor...no spike enargy...and really low G's

Mo,

Based on the spectrum and TWF pattern it does not look to me as a bearing problem at all. Better resolution can determine this conclusively. Please put cursors on the spikes, use frequency units as oppose to orders and correct RPM, so that one can analyze easier.

Is something there in this crusher that has to do with number 8?

David

That is what I was thinking. Is it 8x and the input speed in your calc is off a bit?

i'v been thinkin the same....so i suspected the coupling jaws....turns out they r 12 not 8..
i'd still suspect it but there is no 2XTS and 3XTS..

quote:

Originally posted by David_G:
Mo,

Based on the spectrum and TWF pattern it does not look to me as a bearing problem at all. Better resolution can determine this conclusively. Please put cursors on the spikes, use frequency units as oppose to orders and correct RPM, so that one can analyze easier.

Is something there in this crusher that has to do with number 8?

David