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fburgos

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Reply with quote  #16 
look at the right, its mm/s rms, quite high probabilities for generator misalignment
John from PA

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Reply with quote  #17 
Quote:
Originally Posted by fburgos
look at the right, its mm/s rms, quite high probabilities for generator misalignment


Your "other" right 😃

Untitled.jpg 
OLi

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Reply with quote  #18 
Thank's I am blind, so it's on the high side. You have relatively hi also tangential, that is strange. I really would like to know where the sensor(s) are mounted.
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fburgos

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Reply with quote  #19 
Quote:
Originally Posted by John from PA


Your "other" right 😃

Untitled.jpg 


Ohh you're right.

I think azima encourages measurement at the top of the bearings/pedestals, tangential usually is what I call horizontal
ruben

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Reply with quote  #20 
.
mira a la derecha, sus mm / s rms, probabilidades bastante altas de desalineación del generador [/ QUOTE]

Yes Burgos, generator is misalignment and coupling wear slightly.
The customer was informed two years ago[cool] more or less.
ruben

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Reply with quote  #21 
[QUOTE = OLi] Gracias estoy ciego, así que está en el lado positivo. Tienes relativamente hi también tangencial, eso es extraño. Realmente me gustaría saber dónde están montados los sensores. [/ QUOTE]

Accelerometer triaxial is mounted in that bearing in tangential position but the real problem is in axial and radial: coupling wear and misalignment). The misalignment was detected two years ago more or less and little by little the coupling wear pattern has gone rising obviusly.

But my strange pattern It is much earlier than these problems.
John from PA

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Reply with quote  #22 
ruben, I gather from some comments you've made before that your intent is to post content to this forum in English, but it is occasionally translated to Spanish.  If you use Google Chrom,e as your browser, you might want to go in and disable the "automatic" translation.

To turn off Google auto translation:
  1. Open Google Chrome browser.
  2. In the top right corner of the browser window, click the Chrome menu.
  3. Select Settings.
  4. Scroll down and click Show advanced settings.
  5. In the "Languages" section, uncheck "Offer to translate pages that aren't in a language you read" box.
ivibr8

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Reply with quote  #23 
Up to this point I've just been an interested bystander (that's how I learn [smile]) to this post.
I have no significant input other than to say that I also used Azima EAV for over 30 years and was very comfortable with the log scaling.  

So, linear or log ---- whatever you are used to.  There is no right or wrong

But others on this post remind us that the level of sidebands is low and more importantly NOT uncommon for gearboxes.   Google any technical writeup and you will see the details.
I have monitored many gearboxes and these sidebands/modulations  whatever you want to call them, are almost always present. 

I realize you are looking for the REASON.....and it is complex (pressure pulses, torque pulses, slight gearing imperfections, the FFT process itself) and not easily explained in a few posts.

I think (as others have pointed out) the prudent COA is to maintain a good average (as DLI Azima preaches) and watch for "changes".  This will be the key to being a good steward of your PdM program and being on top of these gearbox issues.

Best regards
Jim P

post edit - Suggest that you keep the Radial Tangential and Axial scaling to be the same.  It will help you and others quickly see where most of the energy is coming from. Different scaling causes my head to hurt
OLi

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Reply with quote  #24 
Well, still would like to know if this is collected on top of the bearing upper cover or somewhere else? It do happen that the top part you can access is less than perfect in attachment to the rest of the bearing for various reasons normally require tightening of the bolts and may be giving funny looking data...... So I try to collect data at the bottom half or at the split just checking the top half so it don't fall off. So Tangential is horiz, Radial is vert and axial is axial?
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