Excessive Vibration
The causes of vibration can vary greatly; from inadequate machinery
mounting to poor roll balance to other external influences. Before
spending money on rolls or machinery, be sure you investigate all
the possibilities.
Check if your line is properly isolated from the vibration of adjacent
machinery. Improper roll mounting can also cause vibration. Webex
can help identify your first critical speed based on your operating
parameters. Knowing this, you can better plan your lines' performance.
Roll balance is very important. Some so-called roll suppliers do
not even have dynamic balancing capability. Webex balances all rolls
to tolerances that exceed industry standards. Rolls can become unbalanced
due to a number of causes, including losing counterweights; excessive
wear; buildup such as from coatings; or being bent by careless handling
during maintenance on changeovers.
You can often locate the vibration-causing roll simply by feel.
Vibration testing is also available through firms specializing in
preventive maintenance. Has that roll always vibrated at that speed?
Has the mounting changed? The wrap? Sometimes, a little historical
investigation can turn up the variable that started the problem.
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