Magnetically Assisted Gears

#1

Post by Cherian » Mon, Jan 04, 2021, 4:43 PM UTC

Re: Magnetically Assisted Gears

#2

Post by 0wis » Mon, Jan 04, 2021, 5:03 PM UTC

It looks like a Stirling engine : Perfect on paper but no real world application. Reddit comments seem to agree. However, it really looks like magic. Must have been really fun to build.

Re: Magnetically Assisted Gears

#3

Post by aidenn0 » Mon, Jan 04, 2021, 6:44 PM UTC

0wis wrote: post #2

It looks like a Stirling engine : Perfect on paper but no real world application. Reddit comments seem to agree. However, it really looks like magic. Must have been really fun to build.

I could see it used for fixed-load low-power uses; maybe a trawling motor?

Re: Magnetically Assisted Gears

#4

Post by trianglem » Mon, Jan 04, 2021, 8:24 PM UTC

0wis wrote: post #2

It looks like a Stirling engine : Perfect on paper but no real world application. Reddit comments seem to agree. However, it really looks like magic. Must have been really fun to build.

Well if the failure mode under high load turns it back into mechanical it still seems useful. Not sure what the Eddie current losses mean though.

Re: Magnetically Assisted Gears

#5

Post by mikewarot » Mon, Jan 04, 2021, 10:36 PM UTC

Having made gears for 5 years, the idea of two non-rigid, non-involute surfaces lasting for more than a few seconds while rubbing together just doesn't seem plausible as a "backup when overloaded".

It makes for a nice toy, but there will be losses, primarily through eddy current. Any time you move an magnet past a conductor, it sets up currents in the inductor which oppose motion, those currents create heat while losing energy. You see magnets approaching and departing each other, there will be some current induced, and thus heat generated, and loss incurred. It may, or may not, actually be less friction than proper hardened ground gears properly meshed and lubricated, but I doubt it.

If they can show a system efficiency, then I might be interested. Until then, it is a fairly nice object of art.

Re: Magnetically Assisted Gears

#6

Post by mikewarot » Mon, Jan 04, 2021, 10:44 PM UTC

0wis wrote: post #2

It looks like a Stirling engine : Perfect on paper but no real world application. Reddit comments seem to agree. However, it really looks like magic. Must have been really fun to build.

While there are plenty of toy Stirling engines, they do have real world applications. They are used as heat pumps in cryocoolers, and there are even variants with no moving parts, the Thermoacoustic Sterling Cryocooler.