High levels of vibration on this water pumping station unit had caused maintenance problems and necessitated motors being sent away for refurbishment. The dominant element was at the 10.7Hz pump running speed with an amplitude of over 8mm/sec.
After detailed diagnosis, a pair of tuned dynamic vibration absorbers were designed that could be bolted to the motor whilst it was still in service. Once tuned, they all but eliminated the vibration – not only a very elegant and effective technique, but there is also a hint of magic about it…
“When I went down there afterwards, it was so smooth I thought the motor wasn’t running…” Alan England, maintenance engineer
