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Read our primer articles on Vibration Analysis and Laser Alignment Tools.

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Hi Dear Fajar,
I quote from Technical Associate:
McGraw Hill’s “Dictionary of Mechanical and Design Engineering” defines Eccentricity as:
“the distance of the geometric center of a revolving body from the axis of rotation”.
In other words, an eccentric rotor is one in which the shaft centerline does not line up with the rotor centerline. This results in more weight being on one side of the rotating centerline than the other and causes the shaft to wobble in an irregular orbit. This is inherently unstable and can be the source of troublesome vibration.

GMF occurred not only if there was eccentricity. In normal condition usually gearmesh appear. It was indication there was interaction of a gear-set between gear teeth during one revolution. It is little bit the same as BPF (Blade Passing Frequency). Depending to the load, GMF will increase when your load increase.
The problem would be concerned if hearmonics of GMF and also sidebands come up.

Best Regards,

attend Reliable Plant 2024
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