question about lateral force

[wardo5757]

Hey guys! First post here!
I have a project going and have a question about lateral forces. Imagine a rotor fixed on a shaft, this rotor is sitting in a metal conductive cylinder with a 1/4" gap between the two. Would the attraction keep the rotor from spinning? if so to what effect? Is this resistance or torque measurable?

 

[IRstuff]

What's magnetic? What's not? What exactly are you concerned about? Fundamentally, PM motors spin within a cylinder of magnets, don't they? And, with smaller clearances.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[wardo5757]

sorry, forgot to mention the rotor would have magnets in it. the cyllinder would not be magnetic but would be attracted to the magnets.

 

[sreid]

If the cylinder is Iron [magnetic], there will be eddy current and hystersis drag. If the cylinder is non magnetic, there will be eddy current drag only.

 

[IRstuff]

But where are your windings?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[wardo5757]

no windings, just spinning magnets inside of a shield. like sreid wrote, eddy currents will be the drag. calculating them is a whole other story