Supplier for coaxial electric motor

[John_V22]

I'm designing a test fixture and need a compact coaxial electric motor.

The motor drives two counter rotating fans with tip speeds up to 650 fps (desired), 500 fps (required). The fan diameter has not been selected, but is between 2 to 3 ft. Initial estimates suggest that the total fan power will be below 10 hp. The motor may be water cooled.

I'm looking for recommendations for a supplier for this motor. I see that a MIT student used Maxxon motors for a coaxial drive on a dual prop ducted propeller and I have contacted them.

 

[anorlunda]

ping @jim hardy

 

[jim hardy]

A quick Google search on 'coaxial motor' turned up a plethora of offers to sell, but scant explanations or drawings of the offerings. Most were RC Hobby style.

I cannot imagine a single mechanism that'd produce opposing rotations, everything I've seen employs gears of some sort. There's even a PF thread on the subject,
https://www.physicsforums.com/threads/coaxial-rotors-with-one-motor.909579/ .

This image from that thread shows one mechanical solution.

I think in your shoes i'd contact these folks and explain your need is bigger than hobby but smaller than general aviation.
https://www.contraelectric.com/innovation/the-system-components
Probably an engineer there will know who serves that market niche.

If this is for a one of a kind test bed, and you have a creative machinist partner on the project,
i'd peruse the marine salvage yards looking for the lower unit from an outboard motor so equipped. Maybe you'd get lucky and find one with a blown powerhead for cheap.

That'd be a starting point.

Sorry, i don't know of a source. In my day Boston gear was very creative but not for the DIY-Hobbyist budget.

old jim