Exactly Where the Wear Comes From - Understanding Those Metal Flakes

[M.D. Holloway]

Here is the inside of an industrial gearbox. The below pics are priceless in terms of tribology. Notice the metal flakes from excessive wear. It is bad enough that the gears are wearing out at an alarming rate but the whole box and motor will have to be replaced taking at least a few days. That is pretty costly in terms of downtime for the equipment.

[VINMAN]

Flakes looked ground off? Bad gear meshing or improper clearance?

[M.D. Holloway]

Here is a nice map of the exact metals that would show up in oil analysis - this is of a transmission and engine. I have mostly diesel engines mapped out. I would love to do a straight 6 and a G50!

[M.D. Holloway]

hmm...the tranny didn't post

[M.D. Holloway]

Originally posted by VINMAN
Flakes looked ground off? Bad gear meshing or improper clearance?

not sure - as I remember it was from a Falk gearbox the normally they are pretty good. You wont see that with a SEWEurodrive. I think the customer made the mistake of using crappy oil and never changing it.

[VINMAN]

Bronze gear? Those are some pretty big chunks of metal in there.

[M.D. Holloway]

Yep - ever sense Mr. Babbit can up with the concept that soft metal on hard metal actually produced less friction than hard metal on hard metal, many folks have explored this application with success. At first he was laughed at but later grew favor.

Sometimes the bronze, brass, zinc alloy or copper alloy are used as a sacrificial metal as well.

I have seen worse. In reality, many companies may never change a gear set but they will go through loads of bearings and motors and wonder why.

[lendaddy]

Looks like the effect of gearbox backlash to me. What was the application?

[M.D. Holloway]

Drives a conveyor in a factory - they must have 100 of these.

[lendaddy]

Originally posted by LubeMaster77
Drives a conveyor in a factory - they must have 100 of these.

Not a big candidate for backlash then. Really though, it would seem that that thing would last forever in such a low impact app. Did it go dry?

You should see what we do to our ConeDrive™ reduction boxes. It would probably wig you out.

[island911]

Originally posted by LubeMaster77
hmm...the tranny didn't post

too long of a name.

[widebody911]

Maybe you should have titled this thread Trouble with Tribology

[island911]

Originally posted by LubeMaster77
Yep - ever sense Mr. Babbit can up with the concept that soft metal on hard metal actually produced less friction than hard metal on hard metal, . . .

Are you talkng gears . . . or hydrostatic bearings?

[M.D. Holloway]

Constant use combined with neglect spells failure. when I asked the maint manager how often they chnage the gear oil he laughed and said "we wait till it fails then change the gearbox - what the heck, its only a few hundred bucks."

"Actually, your looking at a few thousand - here why..." I proceeded to explain to him the concept of down-time and direct / indirect cost pools and what kind of dramatic influence reliability actually has on the profitability of a factory. After 30 minutes for working out the math on his white board he agreed. we ended up get 100% of his biz plus 4 other sister plants in a 2 month span.

To date, we are at about a 98% closure rate with 100% customer retention over the past 4 years. Makes a real difference when you have a great product line and provide service that exceeds their expectations.

Like shoot'n fish in a oil drum!

[M.D. Holloway]

Originally posted by island911
Are you talkng gears . . . or hydrostatic bearings?

Yiu can find yellow metal in almost every application these days. Hydrostats are pretty cool. Uses fluid to transfer power, permits remote location of drivetrain - no conventional gear box or conventional clutch, the power linked through hydraulics. They have an almost infinite speed range with constant engine speed- almost instantaneous forward to reverse. The fluid must provide
wear protection for pump and yellow metal corrosion protection as well as being resistant to foaming. Tall order.