Magnetic couplings

Discussion in 'Inboards' started by tomkcook, Sep 3, 2020.

  1. tomkcook
    Joined: Oct 2018
    Posts: 6
    Likes: 1, Points: 1
    Location: UK

    tomkcook Junior Member

    Has anyone seen or had any experience with the use of magnetic couplings to transmit torque through a hull?

    As far as I can see there are a number of advantages. The biggest is that you avoid a hull penetration, but also they give you some alignment tolerance, help to damp vibration and can be designed to slip somewhere north of the peak engine torque output.

    The biggest challenge seems to be how to then transmit the thrust to the hull - requiring some sort of thrust bearing that's happy working in seawater.

    Interested in others thoughts.
    CocoonCruisers likes this.
  2. CocoonCruisers
    Joined: Dec 2015
    Posts: 85
    Likes: 29, Points: 18, Legacy Rep: 10
    Location: Marseille & BuenosAires

    CocoonCruisers Junior Member

    I've googled around that theme recently and got nowhere for my application: it turned out the industrial magnetic couplings for torques like i'd need (~1000 nm) get huge, and they use really small gaps, like 1mm. So i ended up more scared about the discs grinding out a giant hole in case of impact or some alignement problem, than i could ever be about a dripless shaft seal breaking.

    Anyway here's a twist that may make the idea even more attractive in lower power applications:
    Contactless gears:
    X Shore Eelex 800: Could this electric boat become the Tesla of the seas?
    or magnetic gears like used in some wind turbines:
    magnetic gears - Google Search

    I'll be curious where you end up, good luck and keep us posted !
    Last edited: Sep 5, 2020
  3. gonzo
    Joined: Aug 2002
    Posts: 16,394
    Likes: 1,429, Points: 123, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    It's possible. All it takes is a truckload (in your case a lorryload) of cash. The coupler will cost you more than if you buy a high end yacht with a regular shaft, and probably leave money left for beers.
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