Vibration Behavior (cont.)

The second concept that should also be understood is phase relationship of vibrations. For example, if there is some misalignment in a pump, there will often be a phase shift in vibration. This phase shift can alter the overall vibration amplitudes without changing the frequency content, as shown below:

Another case where this effect is common is with coupled imbalance. Often the inboard bearing phase will not match the outboard bearing phase. The effect, whether caused by structural lag, or coupled imbalance, creates a higher vibration amplitude than either force alone.

Terms of use of this document: This document is free for unlimited distribution, provided it is unmodified. No warranty of this information is expressed or implied Payments to Christopher for the effort involved in compiling this information is greatly appreciated. Formatted for viewing on 800 X 600 resolution. All graphics were designed and created by Christopher Olsen, use of these graphics for purposes other than this document is prohibited.

[Sixteen-Eleven, Inc.] [Disclaimer]
Last updated: November 24, 2002