Crazy Idea: Magnetise your gearbox gears
 

This is just a crazy idea I had and thought I'd put 'out there':

Take your well run in manual gearbox apart.
Wrap thick copper wire around each gear and discharge a large capacitor through the wire to magnetize the gears so the tops are north and and the bottoms south. (not left north and right south. Although that may work too)

Now all the gears are magnetized such that they repel each other when the box is put back together.

Due to the very small gaps between gear teeth the repulsive force should be substantial enough to avoid gear tooth contact a lot of the time, and greatly decrease the pressure with which the teeth push on each other all the time.

I have no idea how much difference this would make?? Research Reqd!

You'd still have to add oil. (drag. maybe thinner oil?)
Then there's the issue of all that fine metal that usually accumulates on the sump plug magnet! On a well run in gearbox..?

It'd be great if some one here knows the maths in this and can chip in so I don't have to go look it all up! :)

Interesting in principal. However due to gears being different sizes, they would only align while rotating such that they're repelling part of the time, and would attract an equal portion of the time. I think this would only work with a 1:1 gear - which is 4th gear in most manuals these days. And, the reduction in physical contact would only be as strong as the magnetic force, which is to say, probably millinewtons or less, compared with hundreds of newtons exerted by the engine that needs to transfer between the two gears, forcing them together.

There probably IS friction reduction to be found in manual gearboxes that simply isn't happening because nobody is building new manual gearboxes anymore. It's probably also not the lowest hanging fruit yet.

Thx Ecky

The gears would be magnetized top to bottom not left to right if you get my meaning.
ie: The top of each tooth would be say north, and the bottom south.
Then the gears arranged north-north.
ie: Constant repulsion.

Then magnetic force increases/decreases with the square of distance.
So Force = Magnetic Constant /Distance squared.
So the maths says; when D is 0; F is infinite, regardless of how strong the magnet is...
https://socratic.org/questions/the-f...ionality%20%23

I don't think that's quite the case in principle, but friction from any direct steel to steel contact should be GREATLY reduced.
(you'd also have a thin layer of oil between the teeth)

I've actually never considered magnetizing only small sections of a continuous steel object before. I'm not even certain you can, or how the field would propagate (would it cancel itself out?) and I'm not having any luck searching for an answer.

My best guess is that it isn't possible. I imagine the fields would cancel.

EDIT: It appears to be possible. It would likely be a very weak magnet depending on how the poles interact, and would be prohibitively expensive to manufacture. It's a fun thought experiment though.

What's the point? You still need oil. Sturdy stuff too. There are heavy loads inside a gearbox, not just on the gear teeth themselves. Plus it is impossible for the gears to do their jobs at all if they don't impart force from one to the other.

Then they will attract iron particles and wear even faster.

magnetized gears
 

Two things came to mind.
1) The gears are hydrodynamically lubricated. In operation, they never actually make physical contact with one another. So we'd be working on a problem that never existed in the first place.
2) Secondly, if one were to magnetize the gears, they'd be in a position to attract any ferrous metal debris suspended in the gear oil.
It would in essence be like pouring 'sand' into the transmission.
Some race car owners ARE known to epoxy a rare earth magnet to the bottom of a transmission and engine crankcase to attract and 'sequester' any such contaminants. An uncle did this on his cars.

My nearly 30 year old t56 transmission had magnets in the bottom of the case. Along with about 1/8 inch of transmission mud all along the bottom.

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Why magnetize the gears only…???


https://www.youtube.com/watch?v=PRAP_w0eYDA


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Yes one gear shaft is a solid piece.
My guess was that as long as one kept all the norths in the same direction; you'd be fine.
I too looked, but couldn't find info on this. Link?

The other shaft is all separate gears. Easy enough.

And yes; Just a Thought Experiment at this stage.
:)