10-inch axial-flux motor, E-kickscooter

[spinningmagnets]

There's nothing special about another company that will be making / importing a slightly different kick-scooter. However, I noticed that this one had an axial-flux motor inside 12-inch wheels (ID of the tire, OD of wheel), so the motor inside is roughly 10-inches?

I looked for pics, and found just a few. Central stator with overlapping coils...two rotors, one on each side.



View attachment 2



The stator has six groups of six coil ends for 36 (The little brass holes). I don't know how its terminated, of if there are some terminations that are encapsulated inside the stator.

It "appears" to have 18 magnets on each rotor?

 

[Samd]

Nice ron.


Sent from my iPhone using Tapatalk

 

[jonescg]

Very neat package!

 

[spinningmagnets]

These are so thin, that it is feasible to mate two of them side by side for a non-hub ebike system (like a Lebowski), which would have roughly twice the copper fill and magnet-fill of a similar volume of DD hubmotor (which has a lot of air near the center).

They are calling it a 500W motor, but the low speed of the scooter suggests that it might be running 24-ish volts. If so, then it is a 1000W motor on 48V, and two of them is at least 2,000W.

Anyone can make an axial flux in their garage (back shed for the Aussies), but this is interesting because it leverages Chinese mass-production.

For cooling, I noticed that the rotors are attached to the shell, and the stator is on the axle. Cheapest mod would be an air-fan. If making an axial from scratch, maybe consider putting the rotors on the shaft, so the hot stator can have its rim connected to an aluminum shell?

 

[wineboyrider]

What's the efficiency of an axial flux motor?

 

[whereswally606]

ever since seeing lebowskis triple stator axial flux I've been intrigued. Makes me wonder what the limitations are regarding adding more and more stators to get something into the car EV power range?

 

[Toorbough ULL-Zeveigh]

why wuzn't LockH(eed) all over this a year ago¿
'Joule effect'

A year late, two months since the last update and every time the creator does appear, he bullshits his ass off. It's a shame, it's a good looking scooter.

[youtube]YcWCMdbnNb8[/youtube]


so not vapourware but still a long ways from leveraging chinese mass production

We have 5 finished scooters awaiting their marking labels and final packaging. That will be a total of 19 ELECTRICMOOD scooters shipped since the beginning of the Indiegogo campaign deliveries.The production line will stop during the holidays as we all deserve some rest, and will be back online on first week of January.

Engine architecture

Operating principles

The ElectricMood engine is an axial flux permanent magnets brushless engine. The magnets are fixed on the wheel flanks so that the direction of the magnetic flux density is parallel to the rotation axis. The stator is made of conductors driving an electric current within the magnetic gap between magnets. This current combined with the intense magnetic field generates a torque between the rotor and the stator that allows the engine to transform the electric power that it receives into mechanical power.The shape of the engine in this configuration is close to a disk and is suitable for the integration in a vehicle wheel. Moreover, this engine does not produce any resistant torque without current because the stator doesn't contain any ferromagnetic material. This way, it can be used as a free wheel with great efficiency.Architecture of the ElectricMood engine

The rotor

The magnets fixed on both sides of the wheel are rare earth magnets of NdFeB kind. These magnets have a great energy density that allows the production of a very intense magnetic flux density. In addition, the magnetic field produced by these magnets is independent of the surrounding magnetic flux, so they can be considered as uniformly magnetized material. This very specific characteristic has been used to develop a computer codeallowing to predict the magnetic field produced by a given magnet configuration. With this computer code we can optimize the configuration of the engine so as to maximize the torque produced by the engine. The configuration of the magnets used in the design doesn't need any ferromagnetic core to conduct the magnetic field lines, so the overall weight is again lowered.Rotor

The stator

To produce the torque necessary to make the magnets turn and so the wheel, a stator made of electrically conductive material running an electrical current must be placed in the magnetic gap. ElectricMood has developed a technology allowing the usage of printed circuit boards on which copper traces are optimally arranged to minimize the Joule effect electrical losses. In addition to a great current density, this technology provides a great simplicity in the fabrication of the stator. Indeed, in the case of the ElectricMood engine, it is not necessary to wind up isolated copper strands by hand or with expensive machines around a ferromagnetic core.The substrate used for standard printed circuit boards uses composite materials that give them excellent mechanical and thermal properties for a reduced weight. So, de facto, the ElectricMood engine stator is made fromcomposite material.This engine for which ElectricMood has a pending patent provides excellent performance and robustness for a reduced weight and size.Printed circuit of the stator© 2015 ELECTRICMOOD

http://www.electricmood.com/engine_architecture
http://www.google.ca/patents/US20150214801?dq=axial+flux+libault&hl=en&sa=X&ved=0ahUKEwjrzc_XydPRAhWIqFQKHRmyBNwQ6AEIKDAC

 

[spinningmagnets]

I posted this in the motor section because that was the most interesting part for me, and it is unusual to find an affordable axial, much less one in this smaller size range.

I have to admit, the folding configuration is clever. Most show off how easy their scooter is to carry, but I most want one I can drag like wheeled luggage. Plus it "stands up" on its own, instead of needing to lean it into a corner...

I also like how the latch / unlatch mechanism is foot-operated...

 

[gogo]

why wuzn't LockH(eed) all over this a year ago¿

That's it, he's fired.

Seems like coils on PCB have been discussed and thermal issues were a limitation?

 

[spinningmagnets]

I wondered why the stator was green, now it makes sense. If that's the case, then I would go higher volts with a low Kv, and low amps, which...would also allow a cheaper battery pack using common 18650 cells.

I recall seeing DIY wind-generators on otherpower.com, and the coils were laid out and cast into an epoxy. They used marble dust as filler, and the type of epoxy plus marble dust apparently conduct heat well-enough...Those have the coils shoulder-to-shoulder. I recall the Cedric Lynch videos and pics showing overlapping coils, like a row of books that had fallen over at a 30-degree angle.