Pressure compensation of a stepper motor

Hi Ben,

If you don’t need a great deal of torque, might I suggest that you go for a seal-less design and use something like magnetic coupling between two non-contacting shafts through a solid wall instead. I think a company called Sub-Atlantic does this with one of their DC ROV thrusters but I’ve never had one apart………yet….

http://www.f-e-t.com/our_products_technologies/subsea-solutions/rovs-observation/

If you are doing some research and want to take a total tangent, perhaps you could do a theoretical study of the magnetic flux patterns through the wall and look towards optimising the same – see if there is a particular geometric arrangement of magnetic dipoles which provides maximum torque ?

Best Regards,

Grant

P.S always interested in reading new research, so if you do have the time, please onpass to grant.thomson@savante.co.uk, be very pleased to read it.

Hi Savante,

It’s not my website but it is very good for hobby priced ROV ideas.

I work for Sub-Atlantic, I’m the engineering manager here, and I look after R&D for here and Perry Slingsby, as we’re now part of Forum Subsea Technologies, which is in turn part of Forum Energy Technologies, now trading on the New York Stock Exchange (ticker FET).

We don’t do any magnetically coupled thrusters, although I think Sea-Eye do …….

We use shaft seals on our thrusters but we also have something called stator shield (which is patented) where the rotor of the motor is completely encapsulated and enclosed with respect to the stator and drive electronics.

Martin