The "Impossible" verified?

[Don]

Is it true that no physical coupled gear with a two meter radius could spin (accelerate) as efficiently as these MagGears?

http://elanetics.com/physicalgears.html

Want to make sure this statement is correct.

[ecoli]

no advertising

 

(thread under review)

[ecoli]

Thread re-opened.

 

 

How exactly are these gears different than any other gear?

[Don]

They are not practicle for mechanical (forceful) work like ALL physical gears. However, for inertial energy storage (http://elanetics.com/magflywheels.html) they are superior for a number of reasons. The most outstanding being 90 degree coupled gear rotation per tooth interaction. Others are, no physical contact, as a prime mover they can operate in a vacuum enclosure, gear teeth not bound to the circumfrence of the gear wheel, etc.

[Klaynos]

Depends on your definition of "physical contact".

 

How powerful do the magnets have to be, how long do they last?

 

The magnetic intereaction induce a resistance force akin to friction themselves how is this over come?

[Don]

Depends on your definition of "physical contact".

 

How powerful do the magnets have to be, how long do they last?

 

The magnetic intereaction induce a resistance force akin to friction themselves how is this over come?

Physical contact: Touching is having or getting a zero distance; in geometry it refers especially to a tangent line or curve (cf. collision). This term can be used to describe interaction between any physical objects.

 

Will neodymium magnets lose strength over time?

 

Very little. Neodymium magnets are the strongest and most permanent magnets known to man. If they are not overheated, neodymium magnets will lose only about 1% of their strength over 10 years - not enough for you to notice unless you have very sensitive measuring equipment.

 

Resistance? Well none of us are escaping enthropy. Variable torque is present and negligable at one rotation. This "cogging" like effect "vanishes" when the array is accelerated to speed. Please see variable torque for each perimeter unit as illustrated in color graphs located on the Physics page of the website (see link - Magnetic Coupling - Feasibility Study).

 

don

[Klaynos]

You never reach a zero distance, when two things come close to each other the repulsion from the outer electrons interacting via the EM force (oh look the same as your magnets) stop them getting any closer.

 

Yes neodymium magnets will, and the more they are used with each other the more they will lose, you need to remember conversation of energy.

 

But what if they are constantly having reverse applied field action on them, surely that will start to force their domains to align, which if you just measure wont really give you a power reduce but the angle of the field will have changed which will stop your system working.

 

Negligible, could we have some empirical or even mathematical proof of this?

[John Cuthber]

There are real losses due to eddy currents.

On the other hand the idea that the magnets"wear out" isn't a real problem.

The worst position for a magnet to be in from the point of view of demagnetising force is next to another magnet N to N and S to S.

Any combination of gears will sometimes be less strongly demagnetising than this.

Think about an ordinary bar magnet- it is 2 magnets stuck together head to head and tail to tail. If you cut it carefully down the middle you get 2 magnets.

Since ordinary magnets are stable for years there is evidence that these gears should work well.

On the other hand, normal gears are fairly efficient anyway so, except in a few odd situations, it's probably not worth bothering.

The thread's title is misleading. These are not really gears so the fact that you can't have gears without friction doesn't apply. "Something that isn't a gear does something that gears can't" isn't very eye catching.

 

"you need to remember conversation of energy." There's nothing inconsistent with the conservation of energy with using magnetic forces to move things. A magnet has, by virtue of the field) some stored energy. For you to say this energy "goes away" is actually a breach of the conservation principle unless you can say where it goes.

[Don]

Klaynos and Cuthber, thank you both for your observations. It's the critical eye that will refine a project.

 

I'm not too concerned with the blades becoming demagnetized or changing polarity in some way. Their current configuration and proximety are less prone to those effects.

 

It was mentioned that "These are not really gears." A standard definition of a gear is: a toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion. A toothed wheel designed to transmit torque to another gear or toothed component. The teeth of a gear are shaped to minimize wear, vibration and noise, and to maximize the efficiency of power transmission.

 

I believe MagGears do qualify under this general definition. Additionally, there is no LARGE diameter physical gear in existance that can rotate 90 degrees per tooth interaction. Energy is invested each time a physical gear tooth interacts with another. The larger the gear the more teeth the more energy loss through heat build up, etc.

 

Of greater concern are losses due to variable tourqe and eddy currents between perimeter units as you've both noted. This is where I'll need to get MagSoft Corp to perform another feasibility study to identify areas for design improvements. Perhaps lesser strength magnets for perimeter blades, blade shape change, etc. I understand no amount of enginerring will cause these enthropic effects to completely "vanish". I am shooting for the optimal design that reduces these effects the most. Thanks again for the input. Any contribution to the poll above is greatly appreciated.

 

don

[John Cuthber]

Oh, BTW, I think the same problems (eddy currents and demagnetisation) will happen with magnetic bearings. They still work so the idea is perfectly plausible, I'm just not sure how many applications you will find for it. The "gogging" effect ie the variation in torque will be horrible if you only use 4 teeth but I can't see a problem with using lots (OK that's like a conventional gear) but it's still non contact, so no friction and no wear.

It would be interesting to see what the people who do "nano machines" think of this- they have real problems with friction.

[Don]

Agreed.

 

Well, this resolves much of the eddy current and variable torque problems for the five units.

 

Current configuration

...........+

........+ + +

...........+

 

Reduced Eddy Currrent Config

.........+ + + + +

 

Much of it was due to the tips of perimeter blades coming too close to one another. Nevertheless, more work to be done.

 

So, for any brave enough to opine, as to speed alone, any contributions to the poll above is appreciated. Thanks.

 

don

[alan2here]

This looks good.

NIB's last almost forever and are verry powerfull.

This looks like a verry good gearing system if you are looking to reduce friction. You could go one further and reduce nearly all the friction

http://video.google.co.uk/videoplay?docid=-8293799154152880333&q=pyrolytic+graphite&total=13&start=0&num=10&so=0&type=search&plindex=0

I think the thread title is inncurate. However ... we may all see the immposible verry soon

[Don]

This looks good.

NIB's last almost forever and are verry powerfull.

This looks like a verry good gearing system if you are looking to reduce friction. You could go one further and reduce nearly all the friction

http://video.google.co.uk/videoplay?docid=-8293799154152880333&q=pyrolytic+graphite&total=13&start=0&num=10&so=0&type=search&plindex=0

I think the thread title is inncurate. However ... we may all see the immposible verry soon

 

Thanks for the Poll contribution. Using passive magnetic bearings in some applications so we've got that covered. Zero physical contact for all perimeter units (http://www.elanetics.com/design.html -active magnetic bearings shown here).

[alan2here]

There is loads of contact in that diagram you just posted. Please don't just stack up buzzwords and look at my link where there really is no physical contact.

[Don]

There is loads of contact in that diagram you just posted. Please don't just stack up buzzwords and look at my link where there really is no physical contact.

Diamagnetic levitation can be used to levitate very light pieces of pyrolytic graphite. Or, it can be configured to levitate small magnets as shown in your video link. Its force is not very large and has little utility in industrial applications. Thank you for the reference nonetheless.

[cjohnso0]

I'm not sure what the point of this poll is? You need to build and test two similar systems, one with MagGears, one with standard gears. At the least you need to have some theoretical efficiency data. I did see some calc's of inertia and energy but nothing on what you are really trying to prove.

 

I'm not trying to be negative on this but you can't base the validity of a product based on a few guesses with no data to back it up.

 

Also, I'm curious as to whether or not the MagGears can turn a 4400 lb rotor?

[Don]

I'm not sure what the point of this poll is? You need to build and test two similar systems, one with MagGears, one with standard gears. At the least you need to have some theoretical efficiency data. I did see some calc's of inertia and energy but nothing on what you are really trying to prove.

 

I'm not trying to be negative on this but you can't base the validity of a product based on a few guesses with no data to back it up.

 

Also, I'm curious as to whether or not the MagGears can turn a 4400 lb rotor?

 

No point in that. There would be no contest. Much can be determined by appllying vector mathmatics, gear ratios (gr = (π x d) / (π x D) = d/ D), and a little time to the task.

 

Turning (or accelerating) a 4,400 lb rotor would be the lower limit of what MagGears can accomplish.

 

Thanks for your comments.