|
Hi Byron.
You are right. I should have seen it before I asked
the question! What I was thinking was if you put a minnkota motor in
a metal or pvc pod and then filled the pod
with oil or water that would stop the outside water
pressure from trying to get into the pod. What I failed to take into account was
that the minnkota motor would still
have air inside of it that the outside water
pressure would be trying to get to even though the minnkota was surrounded by
water INSIDE the pod. So then the outside water pressure
would still implode a pod that didn't have very
strong walls as you mentioned it couldn't have for the magnetic clutch assembly
to work. You definately made sense and I must
have been having a blonde moment! Lol. The only way
my idea would work would be to first fill the minnkota with transformer oil or
the mystery "Jesus water" I have heard mention of,
and THEN fill the pod with water. That would
work. But there would be no reason to do that. Because once we filled the
motor with oil it would be equalized and there would be no need
for the pod or the magnetic clutch anymore. I
totally see what you mean't. I guess the answer would be to have a strong enough
magnetic clutch that would go thru a thick strong pod's walls
so the pod could withstand the outside water
pressure and as you mentioned 6mm would not be enough wall
strength. Perhaps in the future they will come out with a stronger magnetic
clutch
that would go thru thicker material. Thanks for
keeping me straight.
Bill.
----- Original Message -----
Sent: Sunday, October 23, 2005 7:13
PM
Subject: Re: [PSUBS-MAILIST] RimTec
Magnetic Clutches
Bill, if I understand what you are thinking...I
think I see a potential problem. A "waterproof" motor
housing still has air inside it. The motor is not spinning in
liquid, right? But water proof casings may not be the same
as pressure housings. If this is the case, ( no pun intended) then surrounding
the motor with a liquid wouldnt work at any depth greater than that at
which the motor housing is rated. The ambient pressure of the
outside water would just be transferred via the liquid to the motor
housing. It would still flood/leak at the same depth as it
would if you just sank it alone.
the method you mention is used by lots of sub
people to pressure compensate external battery banks, to thousands of
feet. They use a flexible membrane on the top of the battery box and
fill it with mineral oil. However, the batteries themselves are
liquid filled, and not limited by psi.
I hope that makes sense, and if
not, then I probably misunderstood in the first place!
Byron
Sent: Sunday, October 23, 2005 7:04
PM
Subject: Re: [PSUBS-MAILIST] RimTec
Magnetic Clutches
Hi John.
I was wondering if this idea might be practical
for your applications.
Suspose you rigged your motor to work with the
RimTec magnetic clutches.
Then suspose you filled the inside of the
enclosed casing holding your already waterproof say...minnkota
motor with either oil or water before you sealed it. Then when you were at depth, the
outside water pressure
would not push against the sealed casing
holding the motor. Then you would not need a thick
barrier between the mag plate and the clutch.
Would that work?
Bill.
----- Original Message -----
Sent: Sunday, October 23, 2005 6:04
PM
Subject: Re: [PSUBS-MAILIST] RimTec
Magnetic Clutches
Hello fellow Psubbers,
I have looked very closely
into RimTec magnetic clutches about a year ago. I encourage everyone else
to check it out for themselves but I found they were very limited by the
type of barrier that one could have between the shaft mag plate and the
mag clutch. Less than 6 mm in most cases which was not practical for
my application and the pressure I was looking to work with. The barrier
has to be non-magnetic of course.
There is also a significant
limit to the torque they can transmit through a barrier this thick. Since they are custom made, they
are also very expensive. Much more expensive than building a good quality
shaft seal. I was very hopeful at first but do not feel they would be
successful for a 1 AMT psub. Be sure to check them out for yourself.
John
************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003. Your email address appears in our database because
either you, or someone you know, requested you receive messages from our
organization. If you want to be removed from this mailing list simply
click on the link below or send a blank email message to:
removeme-personal_submersibles@psubs.org Removal of your email address
from this mailing list occurs by an automated process and should be
complete within five minutes of our server receiving your request.
PSUBS.ORG PO Box 311 Weare, NH 03281 603-529-1100
************************************************************************
************************************************************************
************************************************************************
|