It makes sense to be reminded, from time to time, that calendar is not always the best decision-making tool. Actually, it rarely is.
Because, if it was, you would have been dragged out of your 65th birthday party and taken to a hospital for a hip replacement, since statistics say that hip failures happens from that age on, and if your hip is just fine… bad luck, they will “repair” it anyway.
Personally, I somehow prefer it to be done based on REAL CONDITION of MY hip, not statistics and calculations. And, luckily for all of us, that’s exactly how medicine does it.
Unfortunately, bearings do not always have the luxury we have, the luxury to be examined before someone injects something into our bloodstream or replace some of our “parts”.
Fortunately, more and more “doctors and nurses”, in Maintenance and Reliability, care enough and know enough to question the calendar and actually ask the patient (bearing) three simple and effective questions:
- Do you need grease?
- How much?
- Do you feel better now?
You just need to speak the bearing language, and you’ll get your answers loud and clear.
Recently, Mr. Alican Gozuacik and I spent 4 days in training with high performing Jotun team in Turkey, led by Mr. Bahadir Buyukeren, with Hakta Zeren and Kamil Okcu.
It is also important to mention Mr Serdar who was not involved in training until the very end but played highly important role in greasing bearings right.
So, let’s see what we had on the menu:
Two fans with same specs (not using word identical as I do not believe in it, but “same” fans), operating in same conditions (according to how process is supposed to work) and treated with copy/paste time-based lubrication plan.
- Direct drive, 55 kW motors, with 6 313 and 6 315 bearings.
- Lubrication plan based on recommendations:
13 grams every 4 000 hours, both DE and NDE on both motors. - No Ultrasound history data available – no alarms applied at this point.
As assuming seems to be the keyword in many lubrication programs, let me join the club and assume something myself.
I assume that recommendation is wrong.
As it was time to replenish the grease in both motors (according to those 4 000 hours), we used the opportunity to do it. But this time with LUBExpert.
After couple of minutes of basic instructions to Mr. Serdar, he was on his way to replenish grease based on real condition and real bearings’ needs. We did nothing, we simply enjoyed the scene.
And, surprise, surprise… what happened during grease replenishment was not even close to what time-based recommendations were directing Mr. Serdar to do.
Fan 2 Motor NDE:
Planned quantity: 13 grams / proven wrong
Applied: 6.5 grams
Outcome: Lubrication success
Fan 2 Motor DE:
Planned quantity: 13 grams / proven wrong
Applied: 5.2 grams
Outcome: Lubrication success
Fan 1 Motor NDE:
Planned quantity: 13 grams / proven wrong
Applied: 6.5 grams
Outcome: Suspected bearing failure – Data reported to CM team
Fan 1 Motor DE:
Planned quantity: 13 grams / proven wrong
Applied: 5.2 grams
Outcome: Over Lubrication – Bearing didn’t need any grease
Worth mentioning:
Mr. Serdar performed task perfectly and with no assistance from our side.
In addition, LUBExpert collected Dynamic data (TWF and Spectrum) for each bearing before and after grease replenishment process.
That makes Mr. Serdar a member of the Condition Monitoring team, providing highly valuable data.
Let us conclude this interesting and clear case:
- Needs of each bearing were different, opposite to what was assumed;
- None of those needs matched Time-Based plan;
- Following Time-Based plan would actually hurt the bearings;
- Job was done easy, correctly, fast and effectively.
Obviously, there is a good way and bad day to replenish grease.
Your bearings – your choice.
