Re: [PSUBS-MAILIST] motor seals

["Gary R. Boucher" <protek@shreve.net>]

     Some stainless steel is "transparent" to magnetic fields, 
correct.  But, changing or moving magnetic fields will create currents in 
the metal simply because it is conductive.  One thing I had not thought 
about would be sea water.  Sea water is conductive to an extent.  I'm not 
sure how much power a given coupling geometry would give up to heating salt 
water, but I would not think it would be nearly as much as trying to 
penetrate a layer of metal.

GB

At 06:05 AM 8/17/00 , you wrote:

>-----Original Message-----
>From: TeslaTony@aol.com <TeslaTony@aol.com>
>To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
>Date: Wednesday, August 16, 2000 10:27 PM
>Subject: Re: [PSUBS-MAILIST] motor seals
>
>
> >In a message dated 8/15/00 8:03:46 PM Pacific Daylight Time,
> >protek@shreve.net writes:
> >
> >>      The magnets will not be "slowed" by rotation unless there is some
> >>  conductor in the proximity to allow the fields to generate current.  The
> >>  motor will not have to "work harder" to do anything.  The only headache
>is
> >>  trying to create the drive shaft going to the propeller.  If done
>properly
> >>  there will be very little energy loss with the majority of that loss
>going
> >>  into the bearings and any portion of the coupling that has to rotate in
>or
> >>  through the water itself.
> >>
> >>  GB
> >>
> >If you are using ceramics, plastics, aphrodesiacs or anything else that
>isn't
> >conductive, then there are no problems with magnetic fields. Unfortunatly
> >Steel, Aluminum and Titanium are the best for handling maximum pressure
>with
> >minimum thickness, all of which will conduct (maybe not the Titanium, but I
> >bet that it would).
> >
> >If you can get something to handle the pressure, not react to the magnets,
>be
> >strong enough that it can be thin enough to allow proper power transmission
> >and not drain your bank account, all the more power to ya!
> >
> >Anthony
> >
>
>
>
>What about stainless steel??? it is not magnetic..
>
>dale