I am trying to waterproof a small electric motor (submerged) so that
shaft will be sticking out of waterproof enclosure. Can anyone point
me to a source of water sealed bushings or bearings for this sort of
application? I have been looking all over the net and can't seem to
come up with ideas or supplies to do this. The shaft size will be =
1/4"

Thanks!
Bailey--

The problem here is shaft size: it's way too small for our boats and you
will not find a shaft seal in the boating supplies field.
How about industrial supplies? Shaft seals are used in all kind of tanks.


--
Jacques
http://www.bateau.com

"MBS" wrote in message
m...
I am trying to waterproof a small electric motor (submerged) so that
shaft will be sticking out of waterproof enclosure. Can anyone point
me to a source of water sealed bushings or bearings for this sort of
application? I have been looking all over the net and can't seem to
come up with ideas or supplies to do this. The shaft size will be =
1/4"

Thanks!
Bailey--

Don't know which country you are in but check out your ag dealers. I reckon
they will have one to fit your purpose from one of those high pressure
chemical hand sprayers. In Australia look up Hardie.
Brumer


"Jacques Mertens" wrote in message
...
The problem here is shaft size: it's way too small for our boats and you
will not find a shaft seal in the boating supplies field.
How about industrial supplies? Shaft seals are used in all kind of tanks.


--
Jacques
http://www.bateau.com

"MBS" wrote in message
m...
I am trying to waterproof a small electric motor (submerged) so that
shaft will be sticking out of waterproof enclosure. Can anyone point
me to a source of water sealed bushings or bearings for this sort of
application? I have been looking all over the net and can't seem to
come up with ideas or supplies to do this. The shaft size will be =
1/4"

Thanks!
Bailey--

In my experience submerged motors ( as used in submersible pumps) are to
be avoided if at all possible. And for a one-off design, you are putting a
lot of effort into something which will ultimately be unproven and a
potential failure point. You did not say what you are trying to achieve,
power, RPM, depth of submergence, fresh or salt .... Or what you have
available by way of power sources.
Can you go to a flexible shaft and keep the motor above the water? Can you
use pneumatics or hydraulics or a water driven system? What about a
magnetic drive? These are often used on pumps for severe chemical duty to
eliminate the seal problems.
Failing that, I think you are up for an expensive mechanical seal.

David



But I'd look at other ways of doing the job if at all possible.
"BruceM" wrote in message
...
Don't know which country you are in but check out your ag dealers. I
reckon
they will have one to fit your purpose from one of those high pressure
chemical hand sprayers. In Australia look up Hardie.
Brumer


"Jacques Mertens" wrote in message
...
The problem here is shaft size: it's way too small for our boats and you
will not find a shaft seal in the boating supplies field.
How about industrial supplies? Shaft seals are used in all kind of
tanks.


--
Jacques
http://www.bateau.com

"MBS" wrote in message
m...
I am trying to waterproof a small electric motor (submerged) so that
shaft will be sticking out of waterproof enclosure. Can anyone point
me to a source of water sealed bushings or bearings for this sort of
application? I have been looking all over the net and can't seem to
come up with ideas or supplies to do this. The shaft size will be =
1/4"

Thanks!
Bailey--

Thanks for the tips. I should have provided more detail but it will
basically be a fractional horse low depth propulsion (similar to a
trolling motor only much smaller). In taking a trolling motor apart,
the water seal looks like nothing but an "O" ring or grommet next to
the bushing. How complicated can that be? Surely there has to be
something available to accomplish this.

I think it's called a trolling motor ....
DF
"MBS" wrote in message
om...
Thanks for the tips. I should have provided more detail but it will
basically be a fractional horse low depth propulsion (similar to a
trolling motor only much smaller). In taking a trolling motor apart,
the water seal looks like nothing but an "O" ring or grommet next to
the bushing. How complicated can that be? Surely there has to be
something available to accomplish this.

(MBS) wrote in message . com...
Thanks for the tips. I should have provided more detail but it will
basically be a fractional horse low depth propulsion (similar to a
trolling motor only much smaller). In taking a trolling motor apart,
the water seal looks like nothing but an "O" ring or grommet next to
the bushing. How complicated can that be? Surely there has to be
something available to accomplish this.

Try going to an automobile transmissions shop. They have seals and
O-rings and such and have used them plenty. May be they can help you
come up with a practiacl solution. I was thinking a tapered shaft that
seats itself into an oring or a series of orings. If you could cool
it, you might be able to use a teflon block to bear against. Another
possibility would be to have the shaft exit the motor housing from the
bottom. If you knew the vehicle would be upright at all times, you
could use a tube around the shaft to keep an air bubble inside the
housing. I would still use seals, but they might not need to be so
tight, more just to keep splashes from gettin in underneath the unit.
Anyway, good luck and don't let em' tell you it can't be done. Scotty

On 14 Nov 2003 08:46:58 -0800, (MBS) wrote:

I am trying to waterproof a small electric motor (submerged) so that
shaft will be sticking out of waterproof enclosure. Can anyone point
me to a source of water sealed bushings or bearings for this sort of
application? I have been looking all over the net and can't seem to
come up with ideas or supplies to do this. The shaft size will be =
1/4"

Thanks!
Bailey--

I passed your request several times - this is not a topic for
beginners to lightly undertake - but what the hell.
Go to a bearing distributors (look in the phone book)
Ask what shaft seals they have in 1/4 inch.
Pick a likely candidate, and find some tube that will fit the outer
diameter of the seal.
Place three in series in the housing, and fix the housing on the motor
in some waterproof way. This will put you in with a chance.

Brian W Altus OK
p.s. The seals go with the lip facing *outwards*

Brian Whatcott wrote:

Place three in series in the housing, and fix the housing on the motor
in some waterproof way. This will put you in with a chance.

That is not a very promising approach.

If keeping the motor dry is important, filling the housing with a light
oil under slight positive pressure via a compensating bellows is the way
to go. A standard lip seal will keep junk out and the oil in. The
compensating bellows will allow operation to any depth with no fear of
flooding the housing.

Rick

Hmmm....a trolling motor uses a single seal and no depth compensating
bellows.

Still, for decent depths, rather than the shallow depths the
questioner mentioned, this would be a sensible suggestion.
Either way, lip seals
have lips facing the higher pressure side, to prevent lift off, or
they face both ways in some applications....

Brian Whatcott Altus OK

On Sun, 23 Nov 2003 19:56:48 GMT, Rick
wrote:

Brian Whatcott wrote:

Place three in series in the housing, and fix the housing on the motor
in some waterproof way. This will put you in with a chance.

That is not a very promising approach.

If keeping the motor dry is important, filling the housing with a light
oil under slight positive pressure via a compensating bellows is the way
to go. A standard lip seal will keep junk out and the oil in. The
compensating bellows will allow operation to any depth with no fear of
flooding the housing.

Rick