“Resonance issues are a big problem in industry, especially as more drives are converted to variable speed, making this problem more likely to occur. Often seen at 1X of the machine but not always.
Fantastic example here of how destructive resonance problems can be on industrial assets. The customer had numerous issues and failures with a drive system, including multiple motor changes and base modifications with little effect on the problem vibration. The IRIS M Motion Amplification camera survey clearly showed a very directional rocking motion of the motor at 1XRPM. The base was not loose but severely flexing, causing cracking on welds, mostly dipping down on the right-hand side where the base was weakest.
We carried out bump tests with the drive offline using the MA camera and a transient coastdown with my AMS 2140 Analyser, confirming a resonance at 1465 CPM, very close to the operating speed of 1489 RPM. As the customer could not shut down for 12 months to improve the base, we opted for a temporary repair by adding 350Kg of mass to the motor to lower the natural frequency away from the 1489 RPM operating speed. This worked well and reduced the vibration levels from 25mm/sec to 8mm/sec, significantly reducing the stress on the frame and machine until the base can be modified.” — Stuart Walker
Learn more about Motion Amplification.
Learn more about the Emerson AMS 2140.
