# [EVDL] A Fully Submersible EV-Grade motor?



## EVDL List (Jul 27, 2007)

There is no reason you couldn't run the motor in water. If the motor is A/C there is really no problem. The armature of the motor is already insulated and if well made should be water proof, the water would help cool the motor so a smaller motor could put out more power.

Lawrence

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Robert Johnston
Sent: Monday, July 27, 2009 5:23 PM
To: Electric Vehicle Discussion List
Subject: [EVDL] A Fully Submersible EV-Grade motor?

I have an idea that I'd like to try.

Essentially, I want to build a "LandShark", as the original project
seems to have bitten the dust in a big way:
http://web.archive.org/web/20070109161159/http://www.landshark.co.uk/

This is essentially (for those not interested in the link) a 3-wheeled
vehicle (two at the front, one at the back), which is capable of
running on water as well as land. It does this by using a
uniquely-shaped read wheel assembly, where the wheel rim acts as a
high-velocity centrifugal pump, and the wheel arch covers on the front
rotate 180 degrees to act as hydroplanes.

With the original having projected speed capabilities of 200MPH on the
road and 50MPH on water, this could be quite the craft. I'm not
expecting the same kind of performance from an electric setup (though
it would be nice!), but 100mph/25mph would be quite achievable, I
think.

I'd like to try and build some kind of EV version of this craft, but
to do so would require a number of "difficult to find" pieces:

A fully submersible electric motor, preferably a hub-type motor.
High-power and light power storage (LiFePO4, A123 or Supercapacitor
type preferably), again mounted in an entirely sealed (submergible)
container. I'm thinking this would probably be made of fibreglass,
sealed as part of the hull of the vehicle.
Waterproof (Ideally submergible, but potentially "splashproof" may
work) controls (Pedals, brakes, switchgear, pot-box, contactors,
breakers, that kind of thing).

Hopefully, with the right drive system this could make an excellent
"Pleasure craft". It's even possible (though unlikely) that something
like this could be modified for extended range, and used for a
cross-channel (or cross-ocean, if conditions are calm enough) voyage.
-- 
Robert "Anaerin" Johnston
Sent from Regina, Saskatchewan, Canada

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## EVDL List (Jul 27, 2007)

There gas been a group of electric power boat enthusiasts that have been
subjecting their motors to the elements with no water issues for over 10
years that I know of. Water in the motor has never really been a problem, as
long as you don't let rust or other build ups occur, The problems start when
the controller gets wet! -Thos

On Mon, Jul 27, 2009 at 6:37 PM, Harris, Lawrence <


> [email protected]> wrote:
> 
> > There is no reason you couldn't run the motor in water. If the motor is
> > A/C there is really no problem. The armature of the motor is already
> ...


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## EVDL List (Jul 27, 2007)

> Thos True <[email protected]> wrote:
> 
> > There gas been a group of electric power boat enthusiasts that have been
> > subjecting their motors to the elements with no water issues for over 10
> ...


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## EVDL List (Jul 27, 2007)

We have not seen a problem with fully submerging our DC motor in the
electric land rover (as seen in pics on the EV Parts web site). I have
witnessed guys at boating and wheeling events running a garden hose on the
brushes with the motor turning in order to clean the armature of mud and
other debris. As stated earlier, the motor does not mind the water, but high
voltage electronics will not tolerate even the smallest amount in most
cases. -Thos



> Phil Marino <[email protected]> wrote:
> 
> > On Tue, Jul 28, 2009 at 9:41 AM, Thos True <[email protected]> wrote:
> >
> ...


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## EVDL List (Jul 27, 2007)

Water will accelerate brush wear on a DC motor. The R/C racers run in their
new motors submerged in distilled water to seat the brushes quickly. 
Bearings do not tolerate water well at all and it is difficult to keep water
out of them. Windage losses at speed would be enormous. Motors of any type
are generally happier dry.

Stephen Chapman


Thos True wrote:
> 
> We have not seen a problem with fully submerging our DC motor in the
> electric land rover (as seen in pics on the EV Parts web site). I have
> witnessed guys at boating and wheeling events running a garden hose on the
> brushes with the motor turning in order to clean the armature of mud and
> other debris. As stated earlier, the motor does not mind the water, but
> high
> voltage electronics will not tolerate even the smallest amount in most
> cases. -Thos
> 
>


> Phil Marino <[email protected]> wrote:
> >
> >> On Tue, Jul 28, 2009 at 9:41 AM, Thos True <[email protected]> wrote:
> >>
> ...


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## EVDL List (Jul 27, 2007)

Haveing read Reliance's writeup on brushes, I have to agree submersing
the motor is an issue.
The brushes are constantly wearing off and laying down that oxide layer.
It is created by passing a spark through moist air and is a delicate
balance. Maybe they have a brush material for submersed motors? (Want
scary? they run brushed motors submersed in gasoline. Of course it is a
"sparkless" comm graphite on graphite.)


>


> Thos True <[email protected]> wrote:
> >
> >
> >> > There gas been a group of electric power boat enthusiasts that have been
> ...


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## EVDL List (Jul 27, 2007)

Tom True is correct, Jeff - Dave Cloud and Rich Rudman used to race electric 
boats with submerged motors all the time. They claimed that was the only way 
to keep the motors cool!

If the insulation is good, the only issue is bearings - if they are properly 
lubed and dried out afterward, they work OK.

Joseph H. Strubhar

Web: www.gremcoinc.com

E-mail: [email protected]
----- Original Message ----- 
From: "Jeff Shanab" <[email protected]>
To: <[email protected]>
Sent: Tuesday, July 28, 2009 8:10 PM
Subject: Re: [EVDL] A Fully Submersible EV-Grade motor?


> Haveing read Reliance's writeup on brushes, I have to agree submersing
> the motor is an issue.
> The brushes are constantly wearing off and laying down that oxide layer.
> It is created by passing a spark through moist air and is a delicate
> balance. Maybe they have a brush material for submersed motors? (Want
> scary? they run brushed motors submersed in gasoline. Of course it is a
> "sparkless" comm graphite on graphite.)
>
>
>>


> Thos True <[email protected]> wrote:
> >>
> >>
> >>> > There gas been a group of electric power boat enthusiasts that have
> ...


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## EVDL List (Jul 27, 2007)

Sparking while submerged in gasoline is no problem, there is no oxygen,
therefore no combustion. The material choice is to deal with wear.
Stephen Chapman

" (Want scary? they run brushed motors submersed in gasoline. Of course it
is a
"sparkless" comm graphite on graphite.)"



-- 
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Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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## EVDL List (Jul 27, 2007)

Racing is not daily driving. I used to think if it was good for racing
it is better than stock for the street.
In reality, it depends. We already agree that motor cooling is more of
an issue than on the drag strip.

So I I was making a boat that sat in the water every week until I came
out to use it on the weekend, and I trolled around at low amperage until
the pack was dead. (hince measurement is in minutes or hours and not
seconds and a few minutes) Does the ruleing change?

I think accelerated brush wear and more brush drag in addition to
windage drag will result.

> Tom True is correct, Jeff - Dave Cloud and Rich Rudman used to race
> electric boats with submerged motors all the time. They claimed that
> was the only way to keep the motors cool!
>
> If the insulation is good, the only issue is bearings - if they are
> properly lubed and dried out afterward, they work OK.
>
> Joseph H. Strubhar 

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## EVDL List (Jul 27, 2007)

err, until you run out of gas on a day over 73 degrees Fahrenheit. 
Now you have an enclosed space that is 90something % air and just enough
fuel to make a bomb. 1 spark is all you need.

If it is 70 degrees out you can sit in a chair and throw matches into a
bucket of gas, they will usually go out.
If it is 90 degrees you can light the match a few feet away and start
the gas in the bucket on fire.

> Sparking while submerged in gasoline is no problem, there is no oxygen,
> therefore no combustion. The material choice is to deal with wear.
> Stephen Chapman
>
> " (Want scary? they run brushed motors submersed in gasoline. Of course it
> is a
> "sparkless" comm graphite on graphite.)"
>
>
> 

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## EVDL List (Jul 27, 2007)

I build thrusters for underwater propulsion and power tools. They have
special cases to keep the water out. You can run an AC or brushless DC motor
in oil. Refrigeration systems are a common application. The problem with
direct submersion in water is that it will eventually ruin a good motor. On
the other hand the kids that build underwater hobby robots sometimes just
buy cheap DC motors and replace them every trial or have redundancy and
replace as they fail. Any motor that uses brushes will develop problems in
the brushes. They will either deteriorate rapidly and fail or the carbon or
other brush material will pollute the fluid and then carbon up the entire
motor. Running a flooded motor design in air will allow the fluid to heat up
and blow out the seals or worse. Compensators will help but the fluid will
cause the motor to run very hot and without total submersion in water heat
build up can cause other problems. For shallow submersion a dry case is
best. The only added friction is the shaft seals. Cooling when not submerged
in water requires a circulated cooling system to col the case. Siemens
motors.
robC



> Jeff Shanab <[email protected]> wrote:
> 
> > err, until you run out of gas on a day over 73 degrees Fahrenheit.
> > Now you have an enclosed space that is 90something % air and just enough
> ...


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