The Beginning Of The End For Rare Earth Permanent Magnet Motors?

Fri, Oct 2, 2009

Applications, Technology

Okay, okay, so maybe I’m exaggerating just a little… but if the news from Japan today is anything to go by, perhaps we’re not far off.

According to a report at, Japan’s Daikin Industries has teamed up with Professor Shigeo Morimoto from Osaka Prefecture University, to create an electric motor that produced high torque from hard ferrite magnets.

The new design relies on a new way of interfacing “the rotating component and the magnet, as well as between the fixed component and the conductive wire. Both sides are given uneven surfaces, so there is a greater surface area where they meet. This increases the repulsive force created when a current is run through the wire. The uneven surface also enables portions of the two sides to be brought closer together”.

Apparently the prototype of this motor generates 30% more torque than a “conventionally design motor”.  Key to this is no doubt the tiny air gap of just 0.012 inches [0.3mm], which will no doubt present a challenge when scaling things up.

This development re-inforces the comments made earlier this year by Tony Morcos on the subject of alternatives to rare earth permanent magnets for generators.

I’ll post more on this as I find additional details; in the mean time, you can find the report here.

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- who has written 67 posts on Terra Magnetica.

Gareth is a Founding Principal at Technology Metals Research, LLC. He has expertise in a variety of magnetic materials, devices and applications, and their associated trends and challenges, particularly for renewable energy production. For more information check out his biography page. Don't forget to check out Terra Magnetica at Twitter too.

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4 Responses to “The Beginning Of The End For Rare Earth Permanent Magnet Motors?”

  1. Lisa Reisman Says:

    It’s so refreshing to see engineers develop solutions to problems. Product substitution is no stranger to the world of metals. Eventually, as the prices for some of these rarer and hard to source metals rise, companies everywhere will innovate to develop alternatives. They always have and hopefully, always will. Refreshing post!

  2. Tim Starns Says:

    Or, incorporate the REE magnet with the design innovation, and reduce the size and weight of the motor as well as reducing the REE compnent requirement. Seems kinda silly to look at it as strictly an either/or proposition.

  3. Gareth Hatch Says:

    Tim – you make a fair point.


  1. […] hat tip goes to the blog, Terra Magnetica for reporting on an innovation from Japan’s Daikin Industries in conjunction with Professor Shigeo Morimoto from Osaka […]