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Magnax bvba Axial Flux Motors

Posted: Mar 24 2018 7:45am
by LockH
Huh. ESB "Search found 0 matches: Magnax"?

Belgian startup Magnax is currently working on a new generation of electric motors:
https://electricmotorcycles.news/belgia ... ic-motors/

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Tech "scales up" also. :mrgreen:

Re: Magnax bvba Axial Flux Motors

Posted: Mar 24 2018 8:25am
by jonescg
If diameter space isn't an issue, sure. Like say, drive wheels on a replica steam locomotive...

Re: Magnax bvba Axial Flux Motors

Posted: Apr 21 2018 9:11am
by macribs
Forgive me my ignorance but this is hard for me to understand. 15 kw/kilo motor, well that seems well into RC motor territory.

Here is what their website says:
Magnax High-Speed Axial Flux Motors

Extreme Power Densities
  • Magnax High-Speed Axial Flux Motors deliver peak power densities up to 15 kW/kg.
  • A patented system for cooling the windings, for the lowest possible stator temperatures.
  • Dual permanent magnet rotors, for the highest possible torque-to-weight ratio.
  • Yokeless stator, for the shortest possible flux paths and a lower overall weight.
  • Rectangular section copper wire, for the highest possible copper fill factor (90%).
  • Concentrated windings, for the lowest possible copper losses (no coil overhangs).
  • Grain-oriented electrical steel, lowering the core losses by as much as 85%
.
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Can someone explain the cooling for me? From the pic it seems they are ready for water cooling.

Dual rotor?

Yokeless stator?

What is that dual rotor and yokeless stator? Actual known and proven ways or colorful marketing hype?

I am all up for smaller, more powerful motors. And if some come up with new ways to package the copper etc kudos to em. But this I don't understand. All help on the matter would be greatly appreciated.

Re: Magnax bvba Axial Flux Motors

Posted: Apr 22 2018 7:16am
by AussieRider
Looks to me like the "end bells" are the rotors, supported by 2 closely spaced roller bearings.
AussieRider.

Re: Magnax bvba Axial Flux Motors

Posted: Apr 22 2018 11:24pm
by macribs
AussieRider wrote:
Apr 22 2018 7:16am
Looks to me like the "end bells" are the rotors, supported by 2 closely spaced roller bearings.
AussieRider.
You mean like this? Or did I maybe dont understand the meaning of your work "end bells" correctly? Not native english speaker so I struggle with technical english terms.

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What would be the advantages of placing magnets like that? To avoid magnetic "leakage" the use of back iron is well known, and is why the motor housing on a hub motor is so heavy. That way the magnetic force goes in one direction towards the winding and not outside.

If magnets are on the side panel wouldn't that make for the need of thick heavy side panels?

Re: Magnax bvba Axial Flux Motors

Posted: Apr 23 2018 6:54am
by AussieRider
You're right. I should have called them "end plates". End bells is an old term used for conventional brushed motors, generators & alternators. In this motor, it looks like the end plates, which are bolted to that big diameter main shaft, rotate a bit like an RC outrunner. One way to get 2 sets of magnets driven by 1 set of coils I guess.

Re: Magnax bvba Axial Flux Motors

Posted: Apr 24 2018 2:32am
by Hillhater
Daan from Magnax was posting over on the Diycar forum ..
Hi guys,
Thanks for the comments.

I removed the in-wheel picture from the website since it gives people the impression that we do in-wheel powertrains. But we only deliver the AF motor. How customers implement the motor (in-wheel or chassis) is their choice.

The first motor we are going to release is the 265 mm version. This one will have the following specs:

- 5500 RPM
- 265 mm motor diameter
- 86 mm motor length
- Peak power: 300 kW
- Nominal power: 150 kW
- Peak Torque: 521 Nm
- Nominal Torque: 250
- Efficiency at nominal power: 91%, Peak eff. 98%
- Dry mass: 22,5 kg
- Cooling: water

So this gives a power density of 6,7 (nominal) and 13,3 (peak).

The reason why our power densities are so high is because of a new patented cooling system (which seems to be very effective and results in significant higher current density in the windings) and the use of grain oriented electric steel. (much higher flux density in the magnetic cores). And torque = proportional to current density x flux density.

Kind regards,
Daan

Re: Magnax bvba Axial Flux Motors

Posted: Apr 24 2018 5:56am
by macribs
The first motor we are going to release is the 265 mm version. This one will have the following specs:

- 5500 RPM
- 265 mm motor diameter
- 86 mm motor length
- Peak power: 300 kW
- Nominal power: 150 kW
- Peak Torque: 521 Nm
- Nominal Torque: 250
- Efficiency at nominal power: 91%, Peak eff. 98%
- Dry mass: 22,5 kg
- Cooling: water

So this gives a power density of 6,7 (nominal) and 13,3 (peak).
Oh my. I can think of several cool applications for such a beast. :twisted: 8)

Still trying to fully grasp what sets this type of motor apart from bldc, induction, pm etc. If them claims are not drunken ramblings clearly they are doing something right. Is that the case for most axial flux motors or their take in particular? Meaning does other makers of this type of motors come close to them numbers? What about manufacturing costs and production costs of this motor vs other electrical motors? More or less money put into raw material, machining and labor costs for this type of motors?

Can the power & weight be any where near true numbers? No numbers left out, or maybe a DOT sign was forgotten?
The 75-7 is about the same weight with about 75 kw peak output if tweaked well on dyno with some effort on the controller. This Magnax motor, larger diameter, about same case length and close to equal weight as the 75-7 motor output peak power 4 times greater, with insane 3 times the torque. And the efficiencies are high too, well i guess they better as the other numbers are so high.

Is there anything remotely true to these numbers?

If so, what makes the Magnax motor so great? I mean huge power in a rather small package with feather weight vs power output.

Re: Magnax bvba Axial Flux Motors

Posted: Apr 24 2018 9:18am
by Hillhater
I suspect the numbers are only theoretical, and Magnax have not yey produced these motors.
Their main design /business is large dia , direct drive, generator units for wind turbines.

Re: Magnax bvba Axial Flux Motors

Posted: Jun 01 2018 12:06pm
by liveforphysics
macribs wrote:
Apr 24 2018 5:56am
The first motor we are going to release is the 265 mm version. This one will have the following specs:

- 5500 RPM
- 265 mm motor diameter
- 86 mm motor length
- Peak power: 300 kW
- Nominal power: 150 kW
- Peak Torque: 521 Nm
- Nominal Torque: 250
- Efficiency at nominal power: 91%, Peak eff. 98%
- Dry mass: 22,5 kg
- Cooling: water

So this gives a power density of 6,7 (nominal) and 13,3 (peak).
Oh my. I can think of several cool applications for such a beast. :twisted: 8)

Still trying to fully grasp what sets this type of motor apart from bldc, induction, pm etc. If them claims are not drunken ramblings clearly they are doing something right. Is that the case for most axial flux motors or their take in particular? Meaning does other makers of this type of motors come close to them numbers? What about manufacturing costs and production costs of this motor vs other electrical motors? More or less money put into raw material, machining and labor costs for this type of motors?

Can the power & weight be any where near true numbers? No numbers left out, or maybe a DOT sign was forgotten?
The 75-7 is about the same weight with about 75 kw peak output if tweaked well on dyno with some effort on the controller. This Magnax motor, larger diameter, about same case length and close to equal weight as the 75-7 motor output peak power 4 times greater, with insane 3 times the torque. And the efficiencies are high too, well i guess they better as the other numbers are so high.

Is there anything remotely true to these numbers?

If so, what makes the Magnax motor so great? I mean huge power in a rather small package with feather weight vs power output.

Don't confuse the limits of a Sevcon with the limits of the motor.

It looks like they did many things right in this motor, i wish them well.

Re: Magnax bvba Axial Flux Motors

Posted: Jun 01 2018 2:43pm
by LockH
Vid uploaded to YT April 13... Magnax Axial Flux Motor - high speed prototype:

Re: Magnax bvba Axial Flux Motors

Posted: Jun 01 2018 5:56pm
by macribs
Nothing new in the video as far as I can tell, but hey this look like it got potential to be a game changer. The efficiencies alone is amazing. I mean going from high 80's or low 90's to the upper 90's [<95%] would make a big difference. The cooling idea seems great too, not just for the magnets but also for overall less losses that heat will bring such as increased resistance. Use more power to produce torque and not heat. Now lets hope they will get this to market and not only as an OEM product.