Ring thruster with magnetic bearings

In this new design, an electric synchronous motor mover is integrated with a ring propeller in such a way that the motor´s stator in the form of electric windings is built into a nozzle shrouding the propeller, and the motor´s rotor in the form of permanent neodymium magnets is built into the propeller´s ring. The propeller is shaftless, with the ring joining the blades at the tips. The nozzle has radial cavity that accommodates the ring in such a way that the ring inner surface is an extension of the nozzle inner surface, so the nozzle maintains it´s optimal geometry. Furthermore, the ring improves the nozzle-propeller hydrodynamic interaction and efficiency by eliminating the leakage losses between moving blades and the nozzle encountered in traditional designs, such as Kort nozzles. The propeller is supported by and able to transmit the thrust via two self-centered, self-aligned, tapered magnetic bearings that keep the propeller in state of levitation. Magnetic bearings, as compared with roller and journal bearings, have significantly higher efficiency and require less maintenance. The taper enables transmission of both, radial and thrust loads. The propeller´s ring sides perform as the bearing´s journal surface, and the nozzle ring cavity performs as the mating surface.