Outrunner Brushless Motor

[hargard]

Hi
I am trying to find out if a Outrunner Brushless Motor would run in SEA Water totally submerged ??. (before I spend the dosh)
Any thoughts on this would be helpful and useful in my choices for the next RoV design.
I am looking at powering my RoV with Outrunner Brushless Motors as thrusters.
The Esc's would be inside the pressure hull.

Another question is would extending the three wires running to the motor affect the performance. I am looking at 30 cm max.


Regards Hargard RoV Builder

[ghoti]

Forgiive my ignorance. What is RoV? Bill

[vintage1]

Remotely Operated Vehicle (or Vessel)

There is no reason appart from corrosion why any brushless motor won't run fully immersed, but seawaster is a bad thing really.

You probably need to seal it totally with a decent oil and water seal on the shaft outside.

Is this to operate at depth?

[xtal]

You could use magnetic coupling to drive the prop,,
might add too much weight though......
some chemical pumps and fish tank filters use magnetic coupling...

[hargard]

I am developing magnetic drives at the moment for RoV use :) (The biggest challenge to this is the gearbox. cause its gota be a planetary and mounted between the coupling and the prop.)

I am starting on mK 2 and want to make it as simple as possible. This is were the brushless motors would be a simple setup.

Dc motors will run in sea water but the brushes clog and need to be replaced every 5 hours. I just give the motor a dose of WD40 when I’ve finished for the day and they are still running .

The operating depth I dive to atm is 12 meters max as that is the best place to view the wildlife in the sea around the UK. Plus there is still light at that depth.

Regards Hargard RoV builder

[AndyOne]

Replacing motors is easier and probably cheaper than sealing them. You might try replacing the bearings with stainless steel ones. There will of course be the inevitable reactions driven by disimilar metals and its probably a good idea to insulate all electrical connections otherwise this will also cause corrosion.

Andy.

[xtal]

Here's a silly thought...........use artificial fins and electromagnets to move the fins