Anybody Know What This Could Have Been Used For?

[klank]

Whilst on the scrounge from my local scrapyard, I came across this "rotary item" languishing in the bottom of a skip of odds and sods.
The foreman bloke in the yard let me have it for free, provided I could sneak it out past the Boss on the weighbridge!! - (the foreman guy is a scale RC model boat builder who is a very nice bloke and a useful source of good stuff).

It appears to be some sort of rotory magnet.



The main shaft is not magnetic (?stainless or some other very hard alloy - the shaft does not take a file cut) - standing 240mm tall, 35mm. dia in the main, topped with an M16 threaded bit and substantial keyway.
The "rotor" is held by three "vanes" set at a skewed angle.
The "rotor" contains approx. 50 small, very powerful vertical magnets internally mounted around its perimeter.



The top and bottom of the rotor (discs) may well be screwed on - you can just make out the joints.
It is beautifully manufactured and weighs a hell of a lot.

It seems a shame to cut it up, so I am presently using it as a kitchen towel holder, and swarf attractor next to my mill.
(I know there are 50 magnets because the swarf is attracted into 50 discreet small rectangular clumps around the periphery of the rotor.)



One idea suggested to me is that it might have been a magnetic mixing rotor turning in a bath of fluid (hence the vanes skewed).
Interestingly, there are no markings on it apart from a felt tip pen cryptic message written on the shaft "Too Small!"
Presumably thus it was binned, ending up in a skip in my local yard.
The foreman guy had no idea where the skip had come from - somewhere in the East Devon area.

Anyone got any other ideas either as to its original use or what it could be adapted for?

[rleete]

It's a magnetic coupling.  Used in large pumps and valves, where you can't have a shaft protruding through the case.  Could have also been used in mixing equipment, where the impeller is inside (in the stuff to be mixed), and is driven by this doo-hickey outside the tank.

I only know this because I worked in a place that made them a few year back.

[klank]

Wow, small world!!

Thankyou for the information - I appreciate the reply.

[CrewCab]

Wow, small world!!

Thankyou for the information - I appreciate the reply.

Just goes to prove .........   

To be fair though klank, it makes a pretty classy kitchen towel holder

CC

[klank]

What I REALLY want is a Jelly-Snake dispenser for those stressful moments - chewing helps you relax, and a pick-n-mix jelly-snake does the biz.

[websterz]

What I REALLY want is a Jelly-Snake dispenser for those stressful moments - chewing helps you relax, and a pick-n-mix jelly-snake does the biz.

Jelly snake? Is that anything like a gummy worm?

[klank]

Probably!?
Very chewy, brightly coloured (supposedly fruity and no e-number additives -ha ha) about 8" long.
Gummy/yummy.

Better than Jelly Babies.

[Brass_Machine]

Do they have sour ones?

Eric

[rleete]

Well, not to interrupt the candy discussion, but a little more on the original subject.

I worked for a company called Arnold Magnetics for a while.  If you have any of those flat refridgerator magnets, chances are they made them.  They make miles of the stuff, printed with whatever logo and send it all over the world.  They also make magnetic couplings, which is what I worked on.

The ones I worked on looked like a large, square-sided wine glass, about 8" inside diameter, with a shaft on the end (where the stem of a wine glass would be).  Made of steel with the shafts ground and hardened.  Inside this cup, evenly spaced were very strong magnets.  Another shaft, this one without the cup, had magnets fastened to the outside of it.  When placed one inside the other, it forms a coupling, able to transmit a surprising amount of torque.  The huge advantage they have over a direct drive is that they can be designed (based on the size/shape/strength of the magnets) to break free if overtorque is encountered.  They are used where a jam could cause major damage.  By breaking free, they prevent the machinery from destroying itself.  By adding Hall effect sensors, you can add alarms and auto shutoffs to the system. 

The magnets themselves are only about 1" wide, 1/2" thick and 3-4" long.  Plated, rare earth types.  These things are dangerously strong.  Get two within about 4-5 inches of each other, and they will slam themselves together with unbelivable force.  Enough to smash the magnets themselves, and whatever happened to get in the way.  Not a person there had gone very long before discovering this the hard way.  Many pinched fingers with the weaker ones.  If the bigger ones got loose, they could crush fingers.

My job was to figure out a way to attach the magnets safely to the inside of the cup, and outside of the shaft.  Because of their strength, you couldn't just place them by hand.  I ended up using a slide similar to the table on a mill.  Using a gear driven crank to drive the leadscrew, it slowly slid them in place.  They were then bedded in epoxy.

[Bernd]

Roger,

Interesting story. Were I worked they used rare earth magnets on chip conveyors. Inbetween the chips and the magnet was a sheet of stainles steal. It was a real source of entertainment for customers. The chips would travel at an angle and go through a chute that would stop the chips from further travel. The magnets were bolted to a chain every foot or so. This gave the chips a chance to fall out of the chute. A few found out how strong they were. There were always a few that got their fingers pinched.

Bernd

[klank]

Thanks for the most interesting stories.
Makes me want to open the "thing" up and see what's in there - but the end plates are so well made, I can't see how.
It does really attract the swarf though.

Back to sweeties - yes Eric, you can get sour ones - worms (frosted with fine sugar) over here, but much smaller than true Jelly snakes - (which are an epicurian experience).
Fancy a sherbert fountain - with a liquorish "straw" to suck it through - them were the days.