Magnetic gear system

[ombugge]

Magnetic-geared propulsion: a sea change in efficiency and reliability

Marine propulsion systems need to be robust and reliable to withstand the often extreme environments in which they are to operate, whether that is deep-sea pressures, polar temperatures or rough seas. They also need to be able to withstand saltwater corrosion and cope with continual heavy use. Magnetic motor systems are designed for longevity, safety and low maintenance and are ideal for use in challenging marine conditions.

[jimrr]

I’m sure this is on par with the ‘‘magnetic coupling’’ in the new pumps. BUT, on a ship with a few thousand shaft horsepower it’s going to take a sizable current to maintain a magnetic lock on a propulsion shaft, enough i’d kinda doubt it’d be worth saving some shaft seals over?

[powerabout]

its saving a few cogs and some oil to help an electric motor actually be more efficient as the prop wants to go slow, the motor does not.

[aatmunn]

This tech sounds great for cutting down maintenance, but how would it handle rough seas or high stress? It’d be interesting to know if it can keep steady power in tough conditions or if it needs backup.

[ombugge]

Permanent Magnet Rim-driven Thrusters have been around for a while:

Permanent magnet rim-driven thrusters

This also make the gear between motor and propeller unnecessary:

Typically, thrusters would be powered by an induction electric motor, but this new generation developed by KM is making use of permanent magnet (PM) technology that is proving to be more efficient, space saving and with many other operational and environmental benefits.

In a permanent magnet rim-driven thruster, the propeller blades are not driven by a traditional gear line with separate electric motor. Instead, an integrated permanent magnet motor is fitted directly to the periphery of the propeller providing a gearless direct electric drive. The nozzle includes a stator with copper windings inside and permanent magnets are integrated into the outer propeller ring forming the rotor. The ends of the rotor shaft are supported by hydrodynamically optimised stays providing a robust load carrying solution with excellent hydrodynamic performance.

[Steamer]

“It’d be interesting to know if it can keep steady power in tough conditions or if it needs backup.”

In rough conditions power consumed by the screw is anything but steady.