Magnetic gears?

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Greg_Lewis
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Magnetic gears?

Post by Greg_Lewis »

Hi folks. A friend sent me this video of magnetized gears that don't touch. Looks interesting. Do any of you know more about this?

https://www.youtube.com/watch?v=76yRObMIwa0&t=1s
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choprboy
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Re: Magnetic gears?

Post by choprboy »

Eh... its just lots of small magnets attached to wheels and staggered with the poles to always be always be in magnetic repulsion. They also make a number of highly dubious claims:
"no friction" - false, there is clearly friction including friction with the air (compression in the gap) and friction on the axles from radial loading do to magnetic repulsion. Is there less friction than regular gear set?Well, yes, maybe, but at what limited load?
"no needs for precise alignments" - regular gears don't need precise alignment either, but more precision means better load and noise handling vs a none-aligned gear of the same size.
"magnets work in levitation to each other" - what is "leviation".. either magnets are attracting or repelling each other. Maintaining a set distance between magnets is hard in attraction mode because attraction force is inversely proportional to distance. Repulsion mode is inherently self limiting for a given counteracting force.
"Levitation example - magnets do not attact or repel each other" - BS, they are clearly repelling each other. Just because the magnetic poles are arranged to have a short effective distance does not mean they are not attracting or repelling each other when close.
Lew Hartswick
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Re: Magnetic gears?

Post by Lew Hartswick »

What can you expect from the last two generations of "News" people. The education system has abandoned "education" for "feel good" in the classrooms. :-(
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John Hasler
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Re: Magnetic gears?

Post by John Hasler »

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Rick
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Re: Magnetic gears?

Post by Rick »

The big Issue I see is the amount of torque it can transmit. I can't imagine with the size of the magnets very much HP can be transmitted thru it. There have been magnetically coupled pumps and rod less air cylinders around for years. The limiting fact is the strength of the magnets. It may have a use in a low HP/torque application who knows. Gear trains are used to convert HP to either a lower speed/higher torque or higher speed/lower torque output. Seems the second type of gear train would be practical but with the first(increasing torque) it would be very limited.
Its neat but so is a Stirling cycle engine, both are not very practical except for very special applications.
I also wonder why they have two driving "pinions"??? Does it cog really bad with just one pinion?????
It pretty cool anyway.
Rick

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John Hasler
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Re: Magnetic gears?

Post by John Hasler »

Rick writes:
> The big Issue I see is the amount of torque it can transmit. I can't imagine
> with the size of the magnets very much HP can be transmitted thru it.

At high speeds little torque is needed to transmit a lot of power. One of the applications of this technology that is discussed in the literature is as the first speed reduction stage in electric cars. You can improve the power to weight ratio of an electric motor by increasing the speed but quiet, efficient 50,000 rpm gear sets are expensive. Another application could be in gas turbines.
Rich_Carlstedt
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Re: Magnetic gears?

Post by Rich_Carlstedt »

At what cost ?--That is the first thing I see, let me explain
1. Look at $$$$ first, and I see lots of expensive Rare Earth magnets to do a simple job
A ordinary cut gear is 100's of times cheaper for the same duty.
2, Then there is size ..A regular gear transmitting the same torque level is 100's of times smaller
3. Then there is overload capacity, when the Mag gear get overloaded ( and they will) the plastic covering will wear and fail
4. Then there is contamination.. the attraction is always there for particles
5. Then there is weight . No Way can the torque levels needed produce a light weight gear reduction
6. Friction free is a misnomer,the shaft turning has friction

In it;s favor is noise levels....period
So if 1-6 are nothing in the calculation, then it may be a good thing !

Rich
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Bill Shields
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Re: Magnetic gears?

Post by Bill Shields »

There is a reason this appears to be an obscure technology looking for an application
Too many things going on to bother listing them.
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mcostello
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Re: Magnetic gears?

Post by mcostello »

Cars were not considered practical as horses and hay was everywhere. Tomorrow might bring something that makes this better than sliced bagels.
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Bill Shields
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Re: Magnetic gears?

Post by Bill Shields »

When the oil be comes impractical..horses may return. After all.. when things get rough...it is tough to eat a car..
Too many things going on to bother listing them.
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mklotz
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Re: Magnetic gears?

Post by mklotz »

You're comparing to the current, conventional uses for gears. Better to think about applications where the unique aspects of the design are useful.

For example...

Gears that can work through a thin plastic/glass sealing/isolating membrane - think food processing, medical applications, space-based devices.
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atunguyd
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Re: Magnetic gears?

Post by atunguyd »


mklotz wrote: For example...

Gears that can work through a thin plastic/glass sealing/isolating membrane - think food processing, medical applications, space-based devices.
Aaah so social distancing gears then [emoji23][emoji23]

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