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Anyone else just impressed by the writing of the article itself? They made a very good effort of providing benefits over traditional radial flux electric motors

Anyone else just impressed by the writing of the article itself? They made a very good effort of providing benefits over traditional radial flux electric motors and how theirs was difference as well as measurable improvement numbers. I hope they succeed.

ridaj 7y ago
It reads like an ad to me. It's hard to figure out what the catch is, if any (and in this world of tradeoffs, there usually is a catch).
- teraflop 7y ago
  Yes, you could call it an ad, but it reads as much more down-to-earth and straightforward than what most people think of when they think of advertising. They're simply describing what they built, why it was difficult, and why they think it's important, with a minimum of marketing fluff.
- pinkfoot 7y ago
  Heat dissipation.
  - VLM 7y ago
    Bingo... Of course there's plenty of apps where that doesn't matter... we'll see them implemented in "bursty" automobiles a long time before we see them implemented in "continuous" railroad traction motors, for example. Its an interesting time to be alive. I'm not THAT old and when I was a kid a generic NEMA 50 HP industrial electric motor took a crane or at least a large engine hoist to lift, more than 500 pounds for sure, but now there are high end automotive motors that I can easily do bicep curls with (like 40 pounds) VFDs are kinda like that too. What used to be a large rack is now a little tiny DIN unit that handles 10x the power.
- quotemstr 7y ago
  Oh, it's definitely an ad. But it's the good kind of ad, the one that informs you about the existence and advantages of a product that you hadn't heard about. Contrast this throwback style of ad with the modern style of ad, which emotionally engineers you into subconsciously wanting a product that you don't actually need. I would love it if more ads looked like Magnax's.
- ew6082 7y ago
  The catch is that radial motors are balanced magnetically and these are not. All that magnetic force is added to axial pull between the stator and rotor. That means they need a thrust bearing in addition to the guide bearings. This causes increased heat and mechanical losses and probably limits efficiency to somewhat less than a standard electric motor. Hi-E standard motors cap out around 98.8%, these will probably cap a point or two lower.
  - nomel 7y ago
    I don’t have a firm grasp of the article, but isn’t the force balanced in this case since the two rotors, linked together, sandwich the stator? If I understood correctly, this would mean the thrust bearing would only feel the imbalance between the two sides. See: https://m.youtube.com/watch?feature=youtu.be&v=BTuCshX5bc0&t=36 https://m.youtube.com/watch?feature=youtu.be&v=BTuCshX5bc0&t...
    - japanuspus 7y ago
      Agreed, this seems to be an incorrect conclusion. Maybe ew6082 just looked at the asymmetrical figure without reading the text.
      - ew6082 7y ago
        Fair enough. They said that a double rotor version has been developed, but all their prototypes and marketing material are single rotor. We can probably assume that single rotor is all that would fit on an in-wheel design but there are other ways to skin the cat. They would still need to include a light thrust bearing on the double rotor design since you can never assume perfectly balanced air gap and one side or the other will dominate, but the losses would be much lower with that setup.
    - mannykannot 7y ago
      In general, yes, though the article mentions one in-hub motor with a single rotor, for reduced size or weight. I guess an in-hub motor, which also acts as the wheel's axle, has to deal with much larger axial forces, from cornering, than those generated by the motor, so the latter are moot. Also, during operation, is not each magnet in the motor being simultaneously pulled by the pole it is moving towards, and pushed by the pole it is moving away from? If so then, at any given point in the rotation, the axial force would be the net of the two effects.
- TaylorAlexander 7y ago
  One thing I remember is some friends I met with a warehouse full of crazy projects they had worked on. They had a few axial flux motors they were really excited about that they had custom made. They seemed to think it was a superior technology, though I can’t recall the specifics.
Erwin 7y ago
That's how IEEE Spectrum articles generally are: the actual inventors, not journalists, are doing some of the bigger articles. Anyone can subscribe to the paper version and it's $40 for 12 issues international (or $20 in US): https://ieee.omeda.com/ieee/r-paid.do?p=WEBPAID https://ieee.omeda.com/ieee/r-paid.do?p=WEBPAID
mojomark 7y ago
Actually, since you ask, while the subject matter is fascinating I had the opposite reaction and found the writing style a bit distracting. While the author clearly has a command of the field, I found myself needing to re-read several paragraphs because I couldn't differentiate when the author was referring to traditional EM designs and Magnox' new design. I also had a tough time maintaining a mental map of the design configurations he was comparing. More figures would've helped. There was one particular use of "nevertheless" that really through me off. Maybe it's just a difference in how we read (i.e. a me problem). They are obviously making huge strides for a hardware startup if they're already field testing, so writing style opinion differences aside, mucho respect and I hope they succeed as well.

ridaj 7y ago

It reads like an ad to me. It's hard to figure out what the catch is, if any (and in this world of tradeoffs, there usually is a catch).

teraflop 7y ago
Yes, you could call it an ad, but it reads as much more down-to-earth and straightforward than what most people think of when they think of advertising. They're simply describing what they built, why it was difficult, and why they think it's important, with a minimum of marketing fluff.
pinkfoot 7y ago
Heat dissipation.
- VLM 7y ago
  Bingo... Of course there's plenty of apps where that doesn't matter... we'll see them implemented in "bursty" automobiles a long time before we see them implemented in "continuous" railroad traction motors, for example. Its an interesting time to be alive. I'm not THAT old and when I was a kid a generic NEMA 50 HP industrial electric motor took a crane or at least a large engine hoist to lift, more than 500 pounds for sure, but now there are high end automotive motors that I can easily do bicep curls with (like 40 pounds) VFDs are kinda like that too. What used to be a large rack is now a little tiny DIN unit that handles 10x the power.
quotemstr 7y ago
Oh, it's definitely an ad. But it's the good kind of ad, the one that informs you about the existence and advantages of a product that you hadn't heard about. Contrast this throwback style of ad with the modern style of ad, which emotionally engineers you into subconsciously wanting a product that you don't actually need. I would love it if more ads looked like Magnax's.
ew6082 7y ago
The catch is that radial motors are balanced magnetically and these are not. All that magnetic force is added to axial pull between the stator and rotor. That means they need a thrust bearing in addition to the guide bearings. This causes increased heat and mechanical losses and probably limits efficiency to somewhat less than a standard electric motor. Hi-E standard motors cap out around 98.8%, these will probably cap a point or two lower.
- nomel 7y ago
  I don’t have a firm grasp of the article, but isn’t the force balanced in this case since the two rotors, linked together, sandwich the stator? If I understood correctly, this would mean the thrust bearing would only feel the imbalance between the two sides. See: https://m.youtube.com/watch?feature=youtu.be&v=BTuCshX5bc0&t=36 https://m.youtube.com/watch?feature=youtu.be&v=BTuCshX5bc0&t...
  - japanuspus 7y ago
    Agreed, this seems to be an incorrect conclusion. Maybe ew6082 just looked at the asymmetrical figure without reading the text.
    - ew6082 7y ago
      Fair enough. They said that a double rotor version has been developed, but all their prototypes and marketing material are single rotor. We can probably assume that single rotor is all that would fit on an in-wheel design but there are other ways to skin the cat. They would still need to include a light thrust bearing on the double rotor design since you can never assume perfectly balanced air gap and one side or the other will dominate, but the losses would be much lower with that setup.
  - mannykannot 7y ago
    In general, yes, though the article mentions one in-hub motor with a single rotor, for reduced size or weight. I guess an in-hub motor, which also acts as the wheel's axle, has to deal with much larger axial forces, from cornering, than those generated by the motor, so the latter are moot. Also, during operation, is not each magnet in the motor being simultaneously pulled by the pole it is moving towards, and pushed by the pole it is moving away from? If so then, at any given point in the rotation, the axial force would be the net of the two effects.
TaylorAlexander 7y ago
One thing I remember is some friends I met with a warehouse full of crazy projects they had worked on. They had a few axial flux motors they were really excited about that they had custom made. They seemed to think it was a superior technology, though I can’t recall the specifics.

Erwin 7y ago

That's how IEEE Spectrum articles generally are: the actual inventors, not journalists, are doing some of the bigger articles. Anyone can subscribe to the paper version and it's $40 for 12 issues international (or $20 in US): https://ieee.omeda.com/ieee/r-paid.do?p=WEBPAID https://ieee.omeda.com/ieee/r-paid.do?p=WEBPAID

mojomark 7y ago

Actually, since you ask, while the subject matter is fascinating I had the opposite reaction and found the writing style a bit distracting. While the author clearly has a command of the field, I found myself needing to re-read several paragraphs because I couldn't differentiate when the author was referring to traditional EM designs and Magnox' new design. I also had a tough time maintaining a mental map of the design configurations he was comparing. More figures would've helped. There was one particular use of "nevertheless" that really through me off. Maybe it's just a difference in how we read (i.e. a me problem). They are obviously making huge strides for a hardware startup if they're already field testing, so writing style opinion differences aside, mucho respect and I hope they succeed as well.