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Bearing tester Brain picking time / predictive maintenance

Tom O

Tom O

Ultra Member
I just got this off of Facebook Marketplace he says it hums but doesn’t know if it works for $50.00 bucks I had to go for it anyone here used one?

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They are supposed to hum. I think about 5Hz. That's how they test things. Tried to find documentation on the ones they used at NOVA Service Centre years ago but couldn't. If I recall you placed the transducer on the object in question and plugged the output port into a scope. Maybe the new ones read the vibration themselves now...my knowledge is 30 yrs old.

There. That's all I remember. I'm tapping out.
 
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If it is for "vibration analysis" of bearings as a "diagnostic tool"......bahhhh - I see no merit in the device. We had lots of studies done and a company sell the ship one of those type of devices.....take readings, send readings to a guru, pay price , get results....shite!....not worth much as far as I can say. So many factors affecting the operation and function of a machine and bearing. Too many variables to make it worth the effort.

If you are in to vibration analysis and have a steady running and operational machine, maybe you can do something with it but for most part, if the bearing is rated for 35000 hours of operation and you are doing say 200 per year or even 2000 per year.....lots of time to change said bearing and not require a funky machine.

They can be used for some fine tuned alignment...but there are many other precision instruments for that as well....

Just my opinion :)
 
So it makes a noise and then? You listen to the noise plus whatever else Noise comes out of the bearing?
 
I used to do a bit of vibration analysis at work. I would use an accelerometer that was magnetically mounted for the most part and then would take the readings they would then go into the computer and be compared to the other readings that have taken for a history and you’d be able to tell if the defect was on the outer race the inner race a dry bearing gear tooth etc.. it was all based on the frequency that the problem happened when compared to rpm of the shafts involved. The bearing number would have to be known. it did take some time on the computer and it was expensive. I have never used one but you can also buy Relatively inexpensive handheld accelerometers. Something like this.
https://www.amazon.com/AMTAST-Vibra...uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl
 
Predictive maintenance is supposed to be a huge money saver. If you can detect problems before they become big? I'm not sure I even understood this. If you find a bearing is bad, ok take an outage, tear it apart, replace the bearing, put it back together. So if you do that now or later where is the cost savings? I suppose if you do the work while you are down anyway then you could avoid an unexpected outage. I also suppose avoiding a catastrophic failure could prevent equipment from being wrecked. What else here I am missing? I feel like there are more use cases here than I understand.
 
Janger said:
Predictive maintenance is supposed to be a huge money saver. If you can detect problems before they become big? I'm not sure I even understood this. If you find a bearing is bad, ok take an outage, tear it apart, replace the bearing, put it back together. So if you do that now or later where is the cost savings? I suppose if you do the work while you are down anyway then you could avoid an unexpected outage. I also suppose avoiding a catastrophic failure could prevent equipment from being wrecked. What else here I am missing? I feel like there are more use cases here than I understand.
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Breakdown maintenance is the most expensive type of a maintenance program. I was dealing in part with 18000lb gearboxes driven by 1000hp motors. For us to find something way before catastrophic failure would save huge money in the long run. Then we could have the parts ready have the people ready and have the shut down time. When times were good shut down time was worth about $5000 a minute so we had to have our ducks in a row. For me at home it does not mater that much since it is just a hobby not a 24 hour a day 7 day a week operation.
 
@Janger you are not missing anything - "Predictive Maintenance" should be a money saver and allow scheduling for down times and such - I am not a huge fan of it as the whole program usually costs money and lots of time to upkeep, in theory adding to the cost of maintenance. We do oil analysis on our equipment but I have never had a test prove anything. Tests have come back and say the oil is fine but the machine has failed. We also change the oil to match the manufacturers recommendations which dilutes the results and essentially makes trending difficult - but we have to change it to meet OEM standards for other inspection bodies. We did Vibration analysis for a couple years - it was a PITA - ship had to be ballasted, fueled etc to the original test conditions - its a steel hull so there is flex and lots of nuisance vibrations. You had to start and run up machinery to the original test conditions - painful - we always got back results that said "packing gland too tight" or other comments on machines that did not even have the components on them - LOL - nothing beats experience and field results to set up a good maintenance program and then work out when to do the overhauls and changes based on manufacturers recommendations and your experience.

That all being said I suppose one could argue that huge massive machines worth millions that make millions could have some savings if a malfunction was picked up before it happened......
 
thriller007 said:
Breakdown maintenance is the most expensive type of a maintenance program. I was dealing in part with 18000lb gearboxes driven by 1000hp motors. For us to find something way before catastrophic failure would save huge money in the long run. Then we could have the parts ready have the people ready and have the shut down time. When times were good shut down time was worth about $5000 a minute so we had to have our ducks in a row. For me at home it does not mater
that much since it is just a hobby not a 24 hour a day 7 day a week operation.
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Interesting perspectives Brent and Thriller.

Thriller what did those machines do? 1000hp and $5000 a minute? Electrical turbines?

I've heard people in the business at the oil company I used to work at say oil analysis gives huge returns on stationary equipment compressors and such. They said it could double the life of a $200 or $400K engine.
 
I suppose it depends on so many variables. A CAT C18 generator set (roughly 400 KW) will run for about 12 to 15000 hours and then need a full overhaul. The engine design is such that you change out the complete power pack components (Pistons, liners, con rods) , bearings, seals, injectors and pumps and off you go for another 12 to 15K Hours. During that time you do the oil analysis and, if all is correct from the overhaul, nothing goes wrong and you do the overhaul again. Oil changes every 500 hours. Typically the failures will be components changed during the overhaul that the CAT factory rebuilt from cores off of other engines. Lots of the failures have nothing to do with the "oil" part of the engine and are due to all the electronic crap fitted. Somewhere around 50 to 60000 hours we would be looking to install new gen sets. So far we have only had a few "engine" related fails that we caught prior to major issues but that was due to good old fashion listening, looking and feeling not the oil results that said things were good and the cam shaft was getting chewed up (manufacturing defect) ....
 
All good points about preventive maintenance.

In Aviation, a lot of aircraft components are “on condition” (engines, hydraulic systems, fuel systems, landing gear, etc.). Regular analysis of the fluids in them, filters, and on-board vibration monitoring systems gather trend data, not only for the particular aircraft itself, but also fleet-wide. When trends are discovered, fleet-wide replacement/repair action is taken.

As an example: there was a problem with the variable inlet guide vanes / variable stator vanes (VIGV / VSV) on the engines we have on the plane (ours was fine, as discovered by a mandatory inspection). Other operators had compressor stalls, resulting in automatic engine shut-down in flight. (The auto shutdown is to prevent further damage and make a bad situation worse by the affected engine potentially physically destroying itself in flight.) These engines cost Millions of $s each. Turns out the fix to the problem was lubrication of the guide vane’s actuator shafts. All shafts are now lubricated on a pre-set hourly bases going forward (I think it is 600h, but not sure). The trend monitoring software now also looks at the time it takes for the guide vanes to move from stop to stop. As the lubrication breaks down over time (especially in hot, humid conditions), the cycle time starts to increase. Once a pre-set (but still safe) time is reached (so many seconds) a lube job is required and you are good to go again (if after lubing the parameters are within limits). This will prevent compressor stalls caused by VIGVs/VSVs.
All sub-systems on the engines are monitored like that - allowing the engine to remain “airworthy” theoretically indefinitely, thus saving huge amounts of $s in the long run.

So yes, preventive maintenance, in Aviation at least, is standard operating procedure. It works very well. The dispatch reliability of our plane is well over 99% for the fleet worldwide. Ours specifically has only missed a trip once in 5 years since we got it.
 
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FIX IT AT HOME!!

Preventative maintenance is the way to go. I could tell stories for days about getting stuff fixed on the road.

I don’t really understand sending in oil or fuel for testing. Nor do I really understand testing SCA/DCA levels in antifreeze
 
Basically, if you were following the fluid sampling to the 100% end of the fluid life you would get the maximum value for your purchase of the fluids - BUT - everyone still changes the fluids or adds the additives that manufacturers have completed the specific studies for - what are you going to do if a test tells you your last batch of fuel was bad....but you already used it while waiting for the test to come back.....the oil is the same thing....

Here is an example: our engine sump contains 650 litres of oil and during heavy operation will consume 20 to 40 litres a day. This means we are adding that back with fresh oil that contains new additives and other lubrication chemicals that gradually dissipate. Over the course of say a full month we may add back to the engine 400 litres of oil - or pretty much an oil change. We send out the oil for sampling every 250 hours. We rarely get elevated levels of anything back - By the way, the testing that the oil places do starts by filtering the oil very carefully to remove solids so that the oil can be processed through gas chromatography and what ever else they do. So if the oil is full of say solid copper that has not ionized, it will not show up on their testing. You could have a big chunk of rubber or steel in the sample and it will not come back as an issue in the report.

Sooooooo.....We have had several significant fails that costed millions and the oil testing still came back good to go. Why do we do it? Some nerd somewhere thinks it is invaluable as a diagnostic tool and we need to comply with policy.....blows my mind
 
I do oil sampling because I want to monitor certain things

Rear ends (drives/axles) elevated metals may mean a bearing is coming apart, or something else is getting eaten

Engine oil- soot from combustion can be harmful, if it’s heavy enough it can pack piston rings
Also coolant mixing with oil is something to watch

But I agree, I’ve sent in fuel that was so grungy that you couldn’t see through it in a water bottle, and got the big green light it was good to burn

Ssooo I’m somewhat skeptical on them, but feel they have their place. They aren’t fool proof that’s for sure
 
Lots of interesting perspectives here from absolutely useless to saves millions of dollars. I like the forum people know so much stuff.
 
Brent H said:
best forum going in my opinion!
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I have a question for you

I (try to) replace parts before they’re broken. What I mean is, I’ll replace my engine belt tensioners and idler pulleys every two years, take the old ones off and have them for spares on the truck. Just an example, and usually new belts at the same time.

Are you able to do anything similar? You’d think there would be a way to track that you usually get 15000 hours out of a part before it fails, so changing it at 14000 hours is a good idea

I realize a ship is different than a truck, but they both have engines.
 
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