Patent attributes
A propulsion device for a marine vessel, the propulsion device comprising an electrical machine with integral magnetic gearing, which comprises three members, namely a first or inner rotor comprising a first plurality of permanent magnets, a second rotor in the form of a plurality of ferromagnetic pole pieces, and a stator which is associated with a plurality of 3-phase windings and to the periphery of which a plurality of second permanent magnets are fixed. The magnetic pole piece rotor is connected to a drive shaft provided with a propulsion means for providing propulsion to the marine vessel. The first or inner rotor is free to rotate about the drive shaft. The pole pieces of the second rotor are arranged to magnetically couple the permanent magnets of the first or inner rotor to the second permanent magnets on the stator.
