Updated: Mar 31, 2020
What useful life can I expect from a motor, if it is installed and maintained with an eye toward precision?
Reducing vibration no doubt reduces fatigue and failure, as proven by Dr. Werner Von Braun and leading reliability engineering schools, therefore increasing a components life span. We see 80 – 90% of customers paying little to no attention to this initially. It’s the easiest path to lower costs, improved uptime and improved morale. Rule of thumb, lower vibration by 20% and double the life of the bearings. Keeping an eye on precision through vibration reduction has a lasting effect on numerous mechanisms that play a large role in a company’s success.
Below are actual results obtained by implementing and insisting on Precision installation and maintenance, at the world’s largest Pulp and Paper mill.
“Prior to precision state the average life of the subject motors was 19.6 years. We found that by concentrating our efforts on the troublesome and costly motor positions first, and insisting that the hundreds of others vibrating at higher than our new minimum acceptable levels be put into a “Precision State”, we could easily double the life of our electric motors, or conversely, cut the failure rate in half in just four years as we did (average life of 46.1 years). Some eight years later, we can see that the rate has been sustained and now reflects an even high average motor life of 52.8 years.”
– Phil Hendrix, Co-Founder and Owner of Hendrix Precision
Reducing vibration will exponentially improve bearing life and since bearing clearances control most of rotating equipment component life, by association rotating equipment life is increased. For every 20% you lower vibration, you easily double the life of the bearings. Do this on a systematic basis across the plant and you will not believe the other costs that will go down and the uptime that will go up. We accomplish this by applying vibration and precision as follows and used the plant fleet vibration/downtime/cost similar metrics.
Identify the “Top 10” vibrators in each area. Assign responsibility to put in precision state to individual mechanics after proper expectation setting of what “Precision State” is and how to get it without spending more than a few hours of mechanical downtime.Some plants make the mistake of only working on the “Top 10”, Huge Mistake.In our company crew leads were expected to put so many additional equipments in a “precise state”, each month/quarter and results were audited (i.e. no pencils or keyboards “whipping the number”).Mechanics met with precision expectations set to eliminate common assembly errors made in every plant every day by mechanics and construction workers.Work to establish STRICT precision measurements for Fit & Tolerance in plant repair shops and audited (w/ mechanics and 1 engineer) outside repair shops to ensure they work to our standards not theirs, unless they are better.All installs in field will have zero pipe strain, no soft foot and align for thermal growth is needed and to precision alignment expectations.New and rebuilt rotating equipment purchased to G 1.0 Balance Specs.Most Important and Vita is mechanics fill out and turn in to the planner a precision field maintenance worksheet stating “equipment left in precision state or not”. No one scolded if not, they just need to make notes on why they weren’t able to do so. (i.e. Pipe strain, no time to correct – Bearing housing wore out, none in storage need to order bearing housing or Precision alignment not possible, 60 year old base is corroded away).Follow Up, Follow Up, Follow Up on these problems turned in by mechanics and the first line of emergencies. VITAL is the planner, superintendent, whom ever knows “they have the responsibility” to order parts and get back on schedule for repair.
In Conclusion, we know vibration significantly decreases the overall life of all rotating equipment including but not limited to bearings. Lowering the overall vibration of your plant equipment and you will cut your rotating equipment and overall maintenance cost dramatically while increasing uptime and profits.