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I have a number of AHU's that I cannot enter due to site policy.  When the techs go around to lube the motor and fan bearings at the external zerk fittings, I need to give them some indication that enough grease has reached the bearing. 

Permanent mount ultrasonic sensors are a bit costly and I already have accelerometers installed.

Has anyone tried to view a real time time waveform in the monitor mode on a vibration analyzer while greasing a bearing?   

Tags: grease, Bearings, accelerometers, AHU

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Yes, you can try monitoring the high-frequency acceleration waveform. Try selecting a high pass filter setting of 500 to 1000 Hz and a low pass filter setting of 5000 to 10,000 Hz. This restricted frequency range should provide the best indication of bearing friction noise.

You could improve the detection of grease entering the bearing by audio monitoring of the  accelerometer signal. If you're analyzer does not offer this capability, then you could purchase a separate amplifier and headset. Here is one example that I do not own, but it looks interesting:

http://www.baseline-uvla.com/product

You could also purchase  a meter that has both  high-frequency  bearing  detection capability and headphones  for use by the  lubrication  crew. I do not own this product but it looks very interesting: Adash 4900 Vibrio at www.adash.com

 I recommend that you also  disconnect the grease feed tube at the bearing and pump clean grease through until there are no air bubbles.  you should also have an accurate measure of how much grease you are adding to the bearing  to be certain that you're not applying too much; irrespective of the indication  from vibration.

 

Walt

RM

I use the Demod ( gE enveloped acc on MySKF Microlog to use as a greasing guide. I place accelerometer and give two pumps, wait a few seconds, if the envelop level drops, move onto the next machine. If the reading doesn't change you have damage grease wont cure, if the envelope reading goes up with grease, get a set of spare bearings ready.

Should work the same way on the remote sensors, but may mean its a two man job one guy on the analyzer, and one with grease gun.

RM
I use my box all the time to grease motors with and have taught those I've trained to do the same. I use off route, spike energy with a 5kHz high pass filter. Pump a few strokes and watch the overall for change. If grease is the issue (usually denoted by high noise floor in the low frequency area), then the overall line scrolling across your screen will drop like a rock. It should stabilize at a lower value. Remember too that bigger bearings need more grease, and a typical lever action grease gun takes around 22 pumps it so per ounce.
RM

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