Author Topic: HET electric motor massively boosts power, torque and efficiency, reduces weight  (Read 747 times)

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Offline oPossum

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A Texas-based startup has raised US$4.5 million in seed funding to develop and commercialize a remarkable electric motor technology. The father/son team claims the design can massively reduce the size and complexity of electric powertrains while also significantly boosting efficiency and doubling the torque output.

https://newatlas.com/linear-labs-hunstable-electric-motor/60974/

Legit or dodgy?

 

Offline HackedFridgeMagnet

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umm... idk

One warning sign, they mention "disruptive technology" in their first sentence. 

Also wouldn't "power density" the same thing as "total output of any permanent magnet motor of the same size" in this case?

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The result, says Linear Labs, is a truly remarkable motor that produces two to five times the torque density, at least three times the power density and at least twice the total output of any permanent magnet motor of the same size


 

Offline David Hess

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Also wouldn't "power density" the same thing as "total output of any permanent magnet motor of the same size" in this case?

One might be power/weight and the other power/volume.
 
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Offline james_s

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I'm not sure how you could "massively" boost efficiency of electric motors, it's not uncommon to get 85% or better in smaller motors and large motors can be in the mid 90s. Electric motors are already one of the more efficient devices out there.
 

Offline Psi

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I wonder how much it shares in common with this one that was in the news recently.
Also claiming to vastly improve motor efficiency
https://insideevs.com/news/361185/magnax-axial-flux-electric-motor/

It has its own thread here
https://www.eevblog.com/forum/renewable-energy/magnax-yokeless-axial-flux-motor-promises-98-percent-efficiency/
« Last Edit: August 12, 2019, 04:02:03 am by Psi »
Greek letter 'Psi' (not Pounds per Square Inch)
 

Offline digsys

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Our in-wheel motor, we helped develop nearly 15 yrs ago, runs at 98.5% efficiency for a large part of the speed / torque curve. Now commercially made by Marand, with a slight loss of efficiency, but better construction. Admittedly, it is only 20KW (short time) peak, and poor low speed figures, but ideal as the main "run time" motor.
https://renew.org.au/wp-content/uploads/2018/12/marand_high_efficiency_motor.pdf
This pretty much shows the realistic maximum that can be achieved, but once you get into higher torques etc, I'd say we are a long way off. Many of our teams have been working on it for years, and not even close. We've seen plenty of designs that "look good" on paper / test beds, and then vanish.
Hello <tap> <tap> .. is this thing on?
 
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Offline ConKbot

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Only CGI, no actual hardware shown. No specifics given of any tests, just vague comparison numbers. Did they just dso a bunch of simulation work? Maybe build a small motor that was 10w and extrapolate the numbers from there? (Battery researcher press teams love that trick. Test tube cell that was 500 uAh could charge in 10 seconds? ELECTRIC CARS THAT CHARGE IN 10 SECONDS COMING.)
 

Online StillTrying

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"Legit or dodgy?"

Dodgy. :popcorn:

Surely there'd be quite a bit of control and power electronics involved, but that's not mentioned anywhere and there doesn't seem to be even a DVM in their lab.

If they sold Ubeam Ustream for $150m why would they be bothered by $4.5m.
https://www.inc.com/marla-tabaka/this-us-vet-sold-to-ibm-for-150-million-now-he-his-dad-are-revolutionizing-energy-industry.html
« Last Edit: August 12, 2019, 02:35:46 pm by StillTrying »
CML+  That took much longer than I thought it would.
 

Offline f4eru

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unproven but Legit.
This arrangement of the stator is very clever, and simple to manufacture (especially if the stator is broken into multiple sections)
This optimizes the volume, and it has several advantages, to my knowledge over motor architectures:
- compact copper -> better efficiency
- minimal iron  -> better volume, better efficiency
- good but not optimal copper fill factor -> compact, efficient
- shortest magnetic path -> higher torque, less gear reduction needed -> direct drive possible ? (that would mean less cost, better efficiency)
- flexibility of pole width on the stator -> field weakening without a magnetic short circuit on the rotor -> less magnets -> less cost

2, 3 or 4 rotors can be used-> easy scaling in the same package
The external rotor would be ferrite based (cost efficient), the internal rotor would be rare earth.

Multiphase inverters are good to spread and simplify the thermals.

The big elephant in the room with this configuration is to achieve good stator cooling.

With an "oil spill" type cooling, this could be a good EV motor, without a good cooling concept, it's hopeless.

Concerning the startup, it could be that they only want to sell  the concept, or the patents. That has potential if the advantages materialize into cost reduction (not sure about that).
« Last Edit: August 13, 2019, 10:20:28 am by f4eru »
 

Offline f4eru

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Our in-wheel motor
Yes, ironless stators are very efficient, but make the magnet material very expensive due to the high airgap, which is not good for mass market EVs
Also, they are probably difficult to efficiently get to a wide range of field weakening, which is also a must for EVs.

Your motor achieves 1.7kW / kg (probably less with housing, bearings, cooling, etc.), while modern EV synchronous motors achieve 5.5 kW/kg, including housing...

Ironless direct drive is a very good technology, just not the right thing for mass market EVs

 

Offline digsys

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Quote from: f4eru
... Ironless direct drive is a very good technology, just not the right thing for mass market EVs 
I did mention the limitations / shortcomings. Most teams have gone for a 3-4 motor setup - 2x wheel-motors on the front that run only during cruise, and for all regen collection, as they are extremely efficient at doing that. Then either 1 or 2 best-fit / high torque power motors. There are a few types in development and look pretty good. In our case, it will technically be a 4 wheel drive. I work on feeding torque vectoring data to the battery banks, among other areas. And yes, they are expensive for now. The challenge has always been - design and build the best that can possibly be achieved for each class, then way up the hits needed to take for various "final market" production versions. The lightyear project is a perfect example of this.
Hello <tap> <tap> .. is this thing on?
 

Offline f4eru

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The challenge has always been - design and build the best that can possibly be achieved for each class
Yes, this kind of dev for research is cool, and bring up new ideas.
"don't mind the hardware budget, I need the best performance"  :-+
 

Offline max_torque

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I'm not sure they are really comparing apples with apples to get their claimed improvements!

I (as part of a small team of engineers) designed the high performance motors used by Mclaren in their P1 hypercar, and then used in FormulaE. Those motors are, broadly conventional, but feature insane attention to detail to release the performance (in much the same way as a Formula 1 engine is fundamentally the same as the engine in your car, but optimised to the nth degree).  The FE motor runs at well over 20,000 rpm,, weighs well under 20kg and makes over 250 kW (exact numbers are not in the public domain so i can't be too specific).  So, hear you ask, what's the problem? Well, the answer is the COST! a single FE motor costs around £50,000   :scared:   So it's not something you're going to find in your production EV very soon.

No, the challenge for electric machines, is to get performance and efficiency with both low cost, and at high production volumes. You'll note lots of manufacturers using what's called a hairpin type arrangement for the windings, and claiming better performance. However, what they should be specifically claiming is "better performance for a given cost and build volume".  The FE motor i mentioned above has far lower AC and copper losses than any production spec motor, but it can only be hand wound in an extremely tedious, complex and time consuming manner. You simply couldn't build more than a couple of them per week per employee.


This new motor claims to eliminate end windings, ie has all it's copper actively contributing to torque production, but a typical "long thin" form factor modern eMachine only has about 10% of it's windings on the end, so there is no way just that could contribute to the claimed massive performance increase.

So, until it's production ready, certified and in volume build, lets not all get too excited eh   :-DD
 


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