10 ms·

Axial-Flux Motor with a PCB Stator Is Ripe for an Electrified World

134 points by sohkamyung 5y ago

jaytaylor 5y ago
What are the weight savings? Am I even reading correctly that reduced weight is the main motivation for the change in materials? I've always been under the impression the heavy parts of electric motors were the copper windings, magnets, and outer casing. If nothing else, the name sounds exotic and cool in a futuristic way.
- gameswithgo 5y ago
- adrian_b 5y ago
  The claimed weight savings are because the stator does not use any ferromagnetic materials, i.e. iron alloys, and because the coils are printed on a multilayer PCB instead of being wound on a heavier support. The stator can be made e.g. of aluminum or plastic, so it should be much lighter than an iron stator. In this motor, the only ferromagnetic parts are 2 discs that compose the rotor, which are made of iron alloy discs on which flat permanent magnets are attached. The 2 rotor discs are very thin in comparison with traditional rotors, so they should also be lighter. So the claims about a much lower weight are perfectly plausible. Whether this motor is good for other performance characteristics, e.g. efficiency (the arguments about lower ferromagnetic losses than in a conventional motor are plausible, but it is hard to make PCB windings with low losses at high currents), torque per size or power per size, is much less clear, because no relevant numbers are provided.
PaulHoule 5y ago
I love the detail that this article goes into! I'm not sure if I understand the "25% less carbon" claim in that many motors (electric vehicle motors) are already efficient enough that you couldn't get that much improvement, but maybe you gain something in some applications because the motor is lighter or maybe this motor type can replace less efficient motors.
- pitaj 5y ago
  I interpreted it as less carbon in the manufacturing process and raw materials.
  - sacrosancty 5y ago
    Or less carbon dust worn off the brushes since it's brushless :P All these articles promoting some technology and banging on about environmental friendliness are full of crap. Nobody will buy it for carbon emissions because there's no money in that even if it was genuine. It's just wankery.
    - jnwatson 5y ago
      Until we have a carbon tax.
  - grapescheesee 5y ago
    Agree, I thought it might be an efficiency metric, or a manufacturing process that is 25% better. . . in terms of carbon.
userbinator 5y ago
One wonders how long these will last give their lightweight construction. There are videos on YouTube of century-old motors still operating like new, and of course they can be relatively easily rewound and rebuilt for another century of service. They appear overbuilt compared to ones of similar power today, but that makes them very robust to short-term overloads. The VFD also monitors performance, and the results can be reported via the cloud, if the user wishes. The motor’s software can also be updated in this fashion. Such remote monitoring offers a variety of ways to conserve energy, manage performance, and predict when maintenance may be needed. More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing.
- avianlyric 5y ago
  With this motor rewinding is even simpler. Just swap the PCB (which contains no electronic, only windings), the rest of the motor can remain in place. PCB manufacture is cheap and extremely efficient, far cheaper and more efficient than manual motor winding. > makes them very robust to short-term overloads There’s no reason to believe that these motors will be any less robust. Older motors are robust to overload by virtue of have lots of copper which take a while to heat up, but they have no real ability to detect that overload and prevent the heating effect in the first place. These motors require VFDs to run them, VFDs are perfectly capable of current limiting the power supplied to the coils, to ensure they can never hit a dangerous temperature, thus making them immune to damage caused by overload (they would just shutdown once and freewheel). > More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing. Basically every industrial motor that’s been installed in the last 30years (probably more) is powered by a digital VFD running clever software. The efficiency and control gains provided by AC motors powered by VFDs are unreal. No “traditional” motor can even get close. VFD powered AC motors are more energy efficient, more robust, have precise speed control, any zero consumable parts (bearing might be consumables is certain situations). Unlike older DC motors that have things like carbon brushes that need to be replaced, have speed control achieved by ginormous variostats. Older AC motors are almost useless for anything except specific industrial applications, because you have no speed control, it’s dictated by the grid frequency. VFDs have changed all of this, and made it possible to create motors the size of watermelon that can produce over 300hp. As for the cloud bit, industry likes the idea of equipment that can monitor itself. A network connected VFD can report all manner of interesting data that can help with health and maintenance monitoring, along with intelligent remote diagnostics. Potential allowing people to accurately predict failure not just in the motor, but also in whatever mechanical equipment it’s powering. Ignoring the security aspect for a moment, that an incredible capability to have built directly into your motors.
mrfusion 5y ago
Off topic but I just learned how an induction motor works. It’s basically just making eddy currents and pushing them around. So weird.
microjim 5y ago
Interesting factoids in this article - electric motors consume a little over half of worldwide electricity, and there’s over 800 million sold every year. Would be curious about maintenance on these motors. The bearings would be the first to go, right? Would that still be doable by a local shop?
- justapassenger 5y ago
  Related interesting tibid - car companies made tons of people believe that electric motors are basically their invention, and they’re leading innovation in that area.
  - ricardobeat 5y ago
    Haven’t seen anyone claim they invented electric motors, after all they were used before the ICE, but I don’t think there’s any doubt around how much innovation car companies have brought to electric motors? Almost every single one uses a custom design for efficiency / reliability reasons.
  - dreamcompiler 5y ago
    There's one electric car company that named itself after the inventor of the motor they used. And he died about 60 years before the company was founded so I don't see them claiming to have invented motors. (Okay there's actually a second EV company that named themselves after the same inventor's first name, but they're a fraud.)
- nerdponx 5y ago
  > electric motors consume a little over half of worldwide electricity Stated another way: over half of the world's electricity is used to move stuff.
  - dotancohen 5y ago
    Stated another way: almost half of the world's electricity is used to warm stuff or make noise. Compute power is lost in the error bars. Though I would say that actually moving stuff is probably the best use of such a resource.
MrLeap 5y ago
This article really reads like a parallel dimension turbo encabulator. It hits all the same notes, has a similar cadence and uses many of the same words. This might be my first experience with the kind of media that was parodying. It's kind of fascinating.
- MegaButts 5y ago
  Yeah, I was hoping for a really detailed engineering-heavy article from IEEE but it came across more like an ad. > Fast-forward to today. My company, Infinitum Electric, of Austin, Texas, has developed a PCB stator motor that fits a wide variety of purposes. It then continues to sing the praises of this company throughout the article. There's nothing special about this article to me, which makes me wonder why people like it so much it's #1 on HN right now (genuinely curious, not knocking other people's opinions).
  - patientplatypus 5y ago
    Yeah - if I were to read a technical analysis of a new idea I'd like it to be not an advertisement from the people building said product. This is just an ad.
mrfusion 5y ago
How light could we make a motor that worked on electric fields instead of magnetic fields?
- Turing_Machine 5y ago
  A lot of MEMS motors use electric fields, so... pretty danged light.
- jbay808 5y ago
  Shinsei corporation made a (macroscopic) electrostatic motor that operates on that principle. I guess they did it just out of curiosity because I don't think it has many advantages. It required high voltages and all the active surfaces had to be highly polished to prevent electric arcing. If I recall correctly it had to run in vacuum as well, for the same reason. But it was a pretty cool project.
  - userbinator 5y ago
    Electrostatic motors have been around in some form ever since the earliest experiments with (static) electricity, so they predate even electromagnetic motors. The high voltages required and their relatively low torque has kept them from gaining much use. https://hackaday.com/2017/10/03/ben-franklins-weak-motor-and-other-forgotten-locomotion/ https://hackaday.com/2017/10/03/ben-franklins-weak-motor-and...
- adrian_b 5y ago
  For large motors that work in air, electric fields are not competitive with magnetic fields. The usable magnetic fields are limited by the saturation of the soft ferromagnetic parts or by the demagnetization of the permanent magnets at around 1 to 2 tesla, while the electric fields are limited by the electrical breakdown of the air at around 3E6 V/m. 1 tesla is equivalent with 3E8 V/m (multiplied by the speed of light), so the usable magnetic fields are 100 to 200 times greater than the usable electric fields. So any large motor must be made with magnetic fields, otherwise it would need to be huge for the same torque. On the other hand the motors with magnetic fields have large power losses in conductors (copper losses) and ferromagnetic materials (iron losses). Because of this, while large motors can have an efficiency above 99%, the smaller an electrical motor with magnetic fields is, the lower its efficiency is. So below a certain very small size, the efficiency of a motor with magnetic fields becomes so low that the motors with electric fields become preferable because of their higher efficiency.
freemint 5y ago
I wonder whether this will have benefits for drones.
- chihuahua 5y ago
  If the claims of reduced weight are true, the benefit for drones would be substantial
  - usrusr 5y ago
    Do motors contribute a considerable amount to total drone weight?
agumonkey 5y ago
Weird, there's a dude growing veggies in vertical pot-walls who made his own variant of that. PCB cast stator. He's in texas too. It seems trending.
deleted 5y ago
[deleted]
jbay808 5y ago
The article skips over the obvious downsides of this sort of motor design, which are: - It requires a high volume of rare earth magnets to get good performance. They should be comparing against similar motors with rare earth magnets and integrated drives, which will tend to be very high efficiency and power-dense machines, rather than low cost induction motors. - Copper losses will be high because you typically can't get as good of a fill factor with PCB traces as with wound copper, so the phase resistance will be high, which impacts the efficiency - PCBs are also not especially cheap at the large sizes, layer counts, and specialty copper weights demanded. At scale it may be better to just automate a high performance epoxied winding. - The axial flux design scales somewhat awkwardly. At the inner radius (near the axis of rotation), the surface speed of the rotor is quite low, as is the developed torque from magnetic pressure, so most of the power is generated by the material near the outer radius. At the outer radius, the magnetic flux return path through the rotor backiron is quite long, and the magnetic pole faces are very broad, requiring the backiron to be quite thick. The centrifugal forces also get large there. The inner radius wants to be a high-speed, low-pole-count motor while the outer radius wants to be a low-speed, high-pole-count motor. - Despite the claims about easy cooling, it doesn't seem nearly as easy to cool the stator as with a conventional motor that has the windings coupled to the outside stator where heat can be directly coupled to the environment. - The front and back rotor sections have a very strong static magnetic attraction to each other (they want to clamp down on the PCB), which requires a fairly robust structure to resist.
- melony 5y ago
  Use gold instead of copper?
  - jbay808 5y ago
    Silver, you mean? That's an option, but now we're getting pretty exotic...
    - nine_k 5y ago
      Silver may even be okay from the cost perspective, but it's much harder to chemically etch.
amelius 5y ago
Will the Lorentz forces not rip the traces from the PCB?
ghostly_s 5y ago
IEEE Spectrum publishes press releases as articles?
- tomcam 5y ago
  It has for years now
incompatible 5y ago
"What’s more, PCBs are manufactured by an automated process, which means they’re much more uniform and reliable than hand-wound machines." I would have guessed that manufacturers would have machines for winding motors. Do they really do it by hand?
- kumarvvr 5y ago
  Yeah, they are highly automated. Even a cursory search in Google shows that. However, winding has been a cottage industry in many parts of the world. So, you still have a large ecosystem that uses tools, jigs and fixtures for winding works.
- imtringued 5y ago
  I have no idea what I am talking about but modern slot less motors can't be wound by hand at all.
funstuff007 5y ago
> Our motor generates as much power as a traditional AC induction motor but has half the weight and size, makes a fraction of the noise, and emits at least 25 percent less carbon. This pull quote, which is discussing electric motors, makes no sense.
- nine_k 5y ago
  Maybe they mean the cost of production if the motor? A copy-editing blunder, though.
  - deleted 5y ago
    [deleted]
- dreamcompiler 5y ago
  They're talking about less carbon being emitted by the generators of the electricity to run the motor, because the motor is more efficient than others of equivalent rotational power. No idea if this is true, but I think it's what they mean.
- Animats 5y ago
  emits at least 25 percent less carbon. Brush wear?
- mschuster91 5y ago
  Per [1], even if dated a bit, the efficiency of motors can be improved by 20-30% - which means that assuming a fossil powered electricity source the amount of energy consumed and CO2 produced will be lowered correspondingly, simply because you need 20-30% less electricity for the same power output on the axis. Additional energy and CO2 will be saved by lower system weight (especially if the motor ends up being used in a mobile application like a car or train) and by lower system size. [1] https://www.eceee.org/static/media/uploads/site-2/library/conference_proceedings/eceee_Summer_Studies/2007/Panel_7/7.098/paper.pdf https://www.eceee.org/static/media/uploads/site-2/library/co...
pensatoio 5y ago
> "...and emits at least 25 percent less carbon..." you lost me.
- ggm 5y ago
  The brushes. They shed less? Traditional motors use carbon brushes.
  - dreamcompiler 5y ago
    It's not the brushes because this motor doesn't have any. If it was about brushes they would have said "100% less." They're talking about GHGs produced by generating the electricity that runs the motor.
    - ggm 5y ago
      So it's a restatement to efficiency. Torque/load being the same, this motor has less internal losses. Heat maybe?
danans 5y ago
> Heat pumps, which heat and cool in one system, are another application in which the motor can save energy, ease installation, and reduce noise. Assuming the efficiency gains are real, increasing the max COP ("efficiency") of heat pumps beyond their already astounding levels of near 5 (500%) would be a game changer for heating and cooling. Even at quite cold temperatures (sub freezing), the latest heat pumps achieve a COP of 2.5 (250%), a level at which they beat the efficiency of gas furnaces even when powered by 40% efficient natural gas generated electricity.
- avtolik 5y ago
  Looks like you have watched the most recent video of TechnologyConnections youtube channel :)
  - danans 5y ago
    TechnologyConnections is the best ;) I did indeed borrow his numbers. But also, I installed a whole house heat pump about a year ago so also have real life experience with them, and with my electricity plan, it's even better from a CO2 perspective since it is 100% wind/solar/hydro based.
qwertox 5y ago
> The motor design is based on a printed circuit board [top], the thinness of which allows for a package that is far more compact than an equivalent motor based on a conventional iron core [bottom].INFINITUM ELECTRIC [0] This is misleading. They are comparing the stator of a radial motor to their PCB. The coils of a copper axial motor just aren't that bulky. The copper "wiring" to axial motors look much less complicated [1][2][3] [0] https://spectrum.ieee.org/media-library/a-photo-of-a-comparison-between-such-a-disc-and-a-much-bigger-conventional-motor-based-on-an-iron-stator.jpg?id=29584985&width=992&quality=80 https://spectrum.ieee.org/media-library/a-photo-of-a-compari... [1] https://imgr1.auto-motor-und-sport.de/Radialflussmotor-Elektromotor-169FullWidthOdcPortrait-47446ad8-1819950.jpg https://imgr1.auto-motor-und-sport.de/Radialflussmotor-Elekt... [2] https://www.youtube.com/watch?v=iKN7CLb63ZI&t=56s https://www.youtube.com/watch?v=iKN7CLb63ZI&t=56s [3] https://www.youtube.com/watch?v=iKN7CLb63ZI&t=93s https://www.youtube.com/watch?v=iKN7CLb63ZI&t=93s (same video different timestamp)

134 points by sohkamyung 5y ago

What are the weight savings? Am I even reading correctly that reduced weight is the main motivation for the change in materials? I've always been under the impression the heavy parts of electric motors were the copper windings, magnets, and outer casing. If nothing else, the name sounds exotic and cool in a futuristic way.

gameswithgo 5y ago
adrian_b 5y ago
The claimed weight savings are because the stator does not use any ferromagnetic materials, i.e. iron alloys, and because the coils are printed on a multilayer PCB instead of being wound on a heavier support. The stator can be made e.g. of aluminum or plastic, so it should be much lighter than an iron stator. In this motor, the only ferromagnetic parts are 2 discs that compose the rotor, which are made of iron alloy discs on which flat permanent magnets are attached. The 2 rotor discs are very thin in comparison with traditional rotors, so they should also be lighter. So the claims about a much lower weight are perfectly plausible. Whether this motor is good for other performance characteristics, e.g. efficiency (the arguments about lower ferromagnetic losses than in a conventional motor are plausible, but it is hard to make PCB windings with low losses at high currents), torque per size or power per size, is much less clear, because no relevant numbers are provided.

PaulHoule 5y ago

I love the detail that this article goes into! I'm not sure if I understand the "25% less carbon" claim in that many motors (electric vehicle motors) are already efficient enough that you couldn't get that much improvement, but maybe you gain something in some applications because the motor is lighter or maybe this motor type can replace less efficient motors.

pitaj 5y ago
I interpreted it as less carbon in the manufacturing process and raw materials.
- sacrosancty 5y ago
  Or less carbon dust worn off the brushes since it's brushless :P All these articles promoting some technology and banging on about environmental friendliness are full of crap. Nobody will buy it for carbon emissions because there's no money in that even if it was genuine. It's just wankery.
  - jnwatson 5y ago
    Until we have a carbon tax.
- grapescheesee 5y ago
  Agree, I thought it might be an efficiency metric, or a manufacturing process that is 25% better. . . in terms of carbon.

userbinator 5y ago

One wonders how long these will last give their lightweight construction. There are videos on YouTube of century-old motors still operating like new, and of course they can be relatively easily rewound and rebuilt for another century of service. They appear overbuilt compared to ones of similar power today, but that makes them very robust to short-term overloads. The VFD also monitors performance, and the results can be reported via the cloud, if the user wishes. The motor’s software can also be updated in this fashion. Such remote monitoring offers a variety of ways to conserve energy, manage performance, and predict when maintenance may be needed. More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing.

avianlyric 5y ago
With this motor rewinding is even simpler. Just swap the PCB (which contains no electronic, only windings), the rest of the motor can remain in place. PCB manufacture is cheap and extremely efficient, far cheaper and more efficient than manual motor winding. > makes them very robust to short-term overloads There’s no reason to believe that these motors will be any less robust. Older motors are robust to overload by virtue of have lots of copper which take a while to heat up, but they have no real ability to detect that overload and prevent the heating effect in the first place. These motors require VFDs to run them, VFDs are perfectly capable of current limiting the power supplied to the coils, to ensure they can never hit a dangerous temperature, thus making them immune to damage caused by overload (they would just shutdown once and freewheel). > More points of failure, more opportunities for attack, and more ways to enforce planned obolescence? I'm a software developer, and yet I don't think putting more software in everything is a good thing. Basically every industrial motor that’s been installed in the last 30years (probably more) is powered by a digital VFD running clever software. The efficiency and control gains provided by AC motors powered by VFDs are unreal. No “traditional” motor can even get close. VFD powered AC motors are more energy efficient, more robust, have precise speed control, any zero consumable parts (bearing might be consumables is certain situations). Unlike older DC motors that have things like carbon brushes that need to be replaced, have speed control achieved by ginormous variostats. Older AC motors are almost useless for anything except specific industrial applications, because you have no speed control, it’s dictated by the grid frequency. VFDs have changed all of this, and made it possible to create motors the size of watermelon that can produce over 300hp. As for the cloud bit, industry likes the idea of equipment that can monitor itself. A network connected VFD can report all manner of interesting data that can help with health and maintenance monitoring, along with intelligent remote diagnostics. Potential allowing people to accurately predict failure not just in the motor, but also in whatever mechanical equipment it’s powering. Ignoring the security aspect for a moment, that an incredible capability to have built directly into your motors.

mrfusion 5y ago

Off topic but I just learned how an induction motor works. It’s basically just making eddy currents and pushing them around. So weird.

microjim 5y ago

Interesting factoids in this article - electric motors consume a little over half of worldwide electricity, and there’s over 800 million sold every year. Would be curious about maintenance on these motors. The bearings would be the first to go, right? Would that still be doable by a local shop?

justapassenger 5y ago
Related interesting tibid - car companies made tons of people believe that electric motors are basically their invention, and they’re leading innovation in that area.
- ricardobeat 5y ago
  Haven’t seen anyone claim they invented electric motors, after all they were used before the ICE, but I don’t think there’s any doubt around how much innovation car companies have brought to electric motors? Almost every single one uses a custom design for efficiency / reliability reasons.
- dreamcompiler 5y ago
  There's one electric car company that named itself after the inventor of the motor they used. And he died about 60 years before the company was founded so I don't see them claiming to have invented motors. (Okay there's actually a second EV company that named themselves after the same inventor's first name, but they're a fraud.)
nerdponx 5y ago
> electric motors consume a little over half of worldwide electricity Stated another way: over half of the world's electricity is used to move stuff.
- dotancohen 5y ago
  Stated another way: almost half of the world's electricity is used to warm stuff or make noise. Compute power is lost in the error bars. Though I would say that actually moving stuff is probably the best use of such a resource.

MrLeap 5y ago

This article really reads like a parallel dimension turbo encabulator. It hits all the same notes, has a similar cadence and uses many of the same words. This might be my first experience with the kind of media that was parodying. It's kind of fascinating.

MegaButts 5y ago
Yeah, I was hoping for a really detailed engineering-heavy article from IEEE but it came across more like an ad. > Fast-forward to today. My company, Infinitum Electric, of Austin, Texas, has developed a PCB stator motor that fits a wide variety of purposes. It then continues to sing the praises of this company throughout the article. There's nothing special about this article to me, which makes me wonder why people like it so much it's #1 on HN right now (genuinely curious, not knocking other people's opinions).
- patientplatypus 5y ago
  Yeah - if I were to read a technical analysis of a new idea I'd like it to be not an advertisement from the people building said product. This is just an ad.

mrfusion 5y ago

How light could we make a motor that worked on electric fields instead of magnetic fields?

Turing_Machine 5y ago
A lot of MEMS motors use electric fields, so... pretty danged light.
jbay808 5y ago
Shinsei corporation made a (macroscopic) electrostatic motor that operates on that principle. I guess they did it just out of curiosity because I don't think it has many advantages. It required high voltages and all the active surfaces had to be highly polished to prevent electric arcing. If I recall correctly it had to run in vacuum as well, for the same reason. But it was a pretty cool project.
- userbinator 5y ago
  Electrostatic motors have been around in some form ever since the earliest experiments with (static) electricity, so they predate even electromagnetic motors. The high voltages required and their relatively low torque has kept them from gaining much use. https://hackaday.com/2017/10/03/ben-franklins-weak-motor-and-other-forgotten-locomotion/ https://hackaday.com/2017/10/03/ben-franklins-weak-motor-and...
adrian_b 5y ago
For large motors that work in air, electric fields are not competitive with magnetic fields. The usable magnetic fields are limited by the saturation of the soft ferromagnetic parts or by the demagnetization of the permanent magnets at around 1 to 2 tesla, while the electric fields are limited by the electrical breakdown of the air at around 3E6 V/m. 1 tesla is equivalent with 3E8 V/m (multiplied by the speed of light), so the usable magnetic fields are 100 to 200 times greater than the usable electric fields. So any large motor must be made with magnetic fields, otherwise it would need to be huge for the same torque. On the other hand the motors with magnetic fields have large power losses in conductors (copper losses) and ferromagnetic materials (iron losses). Because of this, while large motors can have an efficiency above 99%, the smaller an electrical motor with magnetic fields is, the lower its efficiency is. So below a certain very small size, the efficiency of a motor with magnetic fields becomes so low that the motors with electric fields become preferable because of their higher efficiency.

freemint 5y ago

I wonder whether this will have benefits for drones.

chihuahua 5y ago
If the claims of reduced weight are true, the benefit for drones would be substantial
- usrusr 5y ago
  Do motors contribute a considerable amount to total drone weight?

agumonkey 5y ago

Weird, there's a dude growing veggies in vertical pot-walls who made his own variant of that. PCB cast stator. He's in texas too. It seems trending.

deleted 5y ago

[deleted]

jbay808 5y ago

The article skips over the obvious downsides of this sort of motor design, which are: - It requires a high volume of rare earth magnets to get good performance. They should be comparing against similar motors with rare earth magnets and integrated drives, which will tend to be very high efficiency and power-dense machines, rather than low cost induction motors. - Copper losses will be high because you typically can't get as good of a fill factor with PCB traces as with wound copper, so the phase resistance will be high, which impacts the efficiency - PCBs are also not especially cheap at the large sizes, layer counts, and specialty copper weights demanded. At scale it may be better to just automate a high performance epoxied winding. - The axial flux design scales somewhat awkwardly. At the inner radius (near the axis of rotation), the surface speed of the rotor is quite low, as is the developed torque from magnetic pressure, so most of the power is generated by the material near the outer radius. At the outer radius, the magnetic flux return path through the rotor backiron is quite long, and the magnetic pole faces are very broad, requiring the backiron to be quite thick. The centrifugal forces also get large there. The inner radius wants to be a high-speed, low-pole-count motor while the outer radius wants to be a low-speed, high-pole-count motor. - Despite the claims about easy cooling, it doesn't seem nearly as easy to cool the stator as with a conventional motor that has the windings coupled to the outside stator where heat can be directly coupled to the environment. - The front and back rotor sections have a very strong static magnetic attraction to each other (they want to clamp down on the PCB), which requires a fairly robust structure to resist.

melony 5y ago
Use gold instead of copper?
- jbay808 5y ago
  Silver, you mean? That's an option, but now we're getting pretty exotic...
  - nine_k 5y ago
    Silver may even be okay from the cost perspective, but it's much harder to chemically etch.

amelius 5y ago

Will the Lorentz forces not rip the traces from the PCB?

ghostly_s 5y ago

IEEE Spectrum publishes press releases as articles?

tomcam 5y ago
It has for years now

incompatible 5y ago

"What’s more, PCBs are manufactured by an automated process, which means they’re much more uniform and reliable than hand-wound machines." I would have guessed that manufacturers would have machines for winding motors. Do they really do it by hand?

kumarvvr 5y ago
Yeah, they are highly automated. Even a cursory search in Google shows that. However, winding has been a cottage industry in many parts of the world. So, you still have a large ecosystem that uses tools, jigs and fixtures for winding works.
imtringued 5y ago
I have no idea what I am talking about but modern slot less motors can't be wound by hand at all.

funstuff007 5y ago

> Our motor generates as much power as a traditional AC induction motor but has half the weight and size, makes a fraction of the noise, and emits at least 25 percent less carbon. This pull quote, which is discussing electric motors, makes no sense.

nine_k 5y ago
Maybe they mean the cost of production if the motor? A copy-editing blunder, though.
- deleted 5y ago
  [deleted]
dreamcompiler 5y ago
They're talking about less carbon being emitted by the generators of the electricity to run the motor, because the motor is more efficient than others of equivalent rotational power. No idea if this is true, but I think it's what they mean.
Animats 5y ago
emits at least 25 percent less carbon. Brush wear?
mschuster91 5y ago
Per [1], even if dated a bit, the efficiency of motors can be improved by 20-30% - which means that assuming a fossil powered electricity source the amount of energy consumed and CO2 produced will be lowered correspondingly, simply because you need 20-30% less electricity for the same power output on the axis. Additional energy and CO2 will be saved by lower system weight (especially if the motor ends up being used in a mobile application like a car or train) and by lower system size. [1] https://www.eceee.org/static/media/uploads/site-2/library/conference_proceedings/eceee_Summer_Studies/2007/Panel_7/7.098/paper.pdf https://www.eceee.org/static/media/uploads/site-2/library/co...

pensatoio 5y ago

> "...and emits at least 25 percent less carbon..." you lost me.

ggm 5y ago
The brushes. They shed less? Traditional motors use carbon brushes.
- dreamcompiler 5y ago
  It's not the brushes because this motor doesn't have any. If it was about brushes they would have said "100% less." They're talking about GHGs produced by generating the electricity that runs the motor.
  - ggm 5y ago
    So it's a restatement to efficiency. Torque/load being the same, this motor has less internal losses. Heat maybe?

danans 5y ago

> Heat pumps, which heat and cool in one system, are another application in which the motor can save energy, ease installation, and reduce noise. Assuming the efficiency gains are real, increasing the max COP ("efficiency") of heat pumps beyond their already astounding levels of near 5 (500%) would be a game changer for heating and cooling. Even at quite cold temperatures (sub freezing), the latest heat pumps achieve a COP of 2.5 (250%), a level at which they beat the efficiency of gas furnaces even when powered by 40% efficient natural gas generated electricity.

avtolik 5y ago
Looks like you have watched the most recent video of TechnologyConnections youtube channel :)
- danans 5y ago
  TechnologyConnections is the best ;) I did indeed borrow his numbers. But also, I installed a whole house heat pump about a year ago so also have real life experience with them, and with my electricity plan, it's even better from a CO2 perspective since it is 100% wind/solar/hydro based.

qwertox 5y ago

> The motor design is based on a printed circuit board [top], the thinness of which allows for a package that is far more compact than an equivalent motor based on a conventional iron core [bottom].INFINITUM ELECTRIC [0] This is misleading. They are comparing the stator of a radial motor to their PCB. The coils of a copper axial motor just aren't that bulky. The copper "wiring" to axial motors look much less complicated [1][2][3] [0] https://spectrum.ieee.org/media-library/a-photo-of-a-comparison-between-such-a-disc-and-a-much-bigger-conventional-motor-based-on-an-iron-stator.jpg?id=29584985&width=992&quality=80 https://spectrum.ieee.org/media-library/a-photo-of-a-compari... [1] https://imgr1.auto-motor-und-sport.de/Radialflussmotor-Elektromotor-169FullWidthOdcPortrait-47446ad8-1819950.jpg https://imgr1.auto-motor-und-sport.de/Radialflussmotor-Elekt... [2] https://www.youtube.com/watch?v=iKN7CLb63ZI&t=56s https://www.youtube.com/watch?v=iKN7CLb63ZI&t=56s [3] https://www.youtube.com/watch?v=iKN7CLb63ZI&t=93s https://www.youtube.com/watch?v=iKN7CLb63ZI&t=93s (same video different timestamp)