Originally Posted by DJ
...one disadvantage it has is the need for two rotors to counteract torque.
I don't understand why this offers any advantage over a static motor. The need to supply power (using say transformer coil slip rings) is a distinct disadvantage. Why not just design a motor driving the rotor through a gearbox?
A good habit to get into is to compare a new concept to a known solution. The advantages and disadvantages over the known solution should be documented. It does actually provide a good reality check to see whether the concept is worth considering or not - you'd be suprised how looking at the details sorts out the good from the bad...
Mart