Hi Vibration domain members;
I have a question, does FFT spectrum show a bearing defect(BPFO, BSF..etc)in addition to the Envelope, sometimes in data analysis I found bearing signature in FFT spectrum ?if yes, in that moment does the bearing has an earlier or development defect?
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Yes, FFT will show bearing frequencies, if there is a defect with the bearing. Enveloping/shock pulse/demodulation are terms used for early detection of impacting/repetitive events. Bearing fault should also show up in velocity FFT and time waveform in g's
Dave
@Registered Member posted:Yes, FFT will show bearing frequencies, if there is a defect with the bearing. Enveloping/shock pulse/demodulation are terms used for early detection of impacting/repetitive events. Bearing fault should also show up in velocity FFT and time waveform in g's
Dave
Hello Mr.Dave
thank you for your reply,
another question, in which stage we can decide if the bearing change is required or no rely on vibration data?
Regards
Abu Nafi
From your vibration training, there should be information about stages of bearing failure. There are many variables that affect a bearing fault, many different rpm's, load, environment, etc. As the bearing degrades the vibration pattern changes along with an increase in G values.
https://www.midlandsrc.com/wp-...on-Publication-1.pdf
https://www.midlandsrc.com/wp-...-Publication-2-1.pdf
The attached document is a good reference for additional knowledge, this document is a guideline, not meant to be a "go/no go" document
Dave
Sometimes you see bearing frequency in FFT but not in demodulation/ enveloping when there is no "impacting" like out of roundness bore or cocked bearing you might see BPFO
