Halbach AF Bicycle Hub Motor

[Toorbough ULL-Zeveigh]

we hav a weener & it's a hubmotor!
really, AF is a natch fit as a hubbie.

patent granted just 2 months ago to boing.

 

[AussieJester]

Safes going to be pissed hehehe

What I'm doing is radically different from anything I've seen.

Has anyone seen a true "Halbach Disc Motor" being built? (that attaches to the rear wheel)

There are lot's of "axial flux" motors of either Standard or Halbach design (both one sided and double sided), but no one seems to have made the jump to a pure ebike solution. Unless someone beats me to it I'll be the first to create the Halbach Disc "ebike specific" motor.

ref: Safes Halbach Disk Motor Ebike Project

KiM

 

[gogo]

^Hehe

patent granted just 2 months ago to boing.

Boing?

 

[AussieJester]

^Hehe

patent granted just 2 months ago to boing.

Boing?

Its a typo should be Boeing

KiM

 

[Affliction]

Safes going to be pissed hehehe

What I'm doing is radically different from anything I've seen.

KiM

Ya where the hell is that troll? I kind of miss him in a wierd twisted sence

 

[AussieJester]

Hes running amok on Motoerdbikes.com now if you want to get your "Safe Hit"
His threads are pretty much just alot of him rambling post after post so he
would probably welcome some 'friendly faces'

KiM

 

[Affliction]

Hes running amok on Motoerdbikes.com now if you want to get your "Safe Hit"
His threads are pretty much just alot of him rambling post after post so he
would probably welcome some 'friendly faces'

KiM

"Running Amok" :lol: I just spilt my coffee! :lol: Sounds like safe... The forum is a bit boring without the entertainment he adds.

 

[TylerDurden]

As previously described, gaps 380A and 380B may be implemented with large dimensions such as, for example, up to approximately 3.0 inches. In such embodiments, this increased distance between Halbach arrays 310A and 320A, and between Halbach arrays 310B and 320B can reduce the efficiency of electric motor 300.

However, such embodiments can nevertheless be useful in applications where efficiency is less important. For example, it is contemplated that such embodiments may be used where one or more rotors of an unmanned aerial vehicle (UAV) utilizing electric motor 300 may be pre-spun (for example, up to several thousand revolutions per minute) using a ground power source such as a battery or direct power connection. In this case, the stored rotational energy in the rotors could then be used to rapidly lift the UAV to adequate surveillance altitudes (for example, several hundred feet) without requiring electric motor 300 to expend its on-board power source to provide such initial vertical lift, thereby permitting the on-board power source to be retained for extended aerial mobility missions.

Lower efficiency for extended missions... ?

 

[Affliction]

.

Lower efficiency for extended missions... ?

Ya that's safe.... My head hurts now after reading that nonsence... Thanks TylerDurden :lol:

 

[Chalo]

Eek. Coker rim? That'll make it "interesting" to try to maintain a constant rotor gap.

 

[Gavin53]

New to this site, but not the topic.
Interesting, over a year ago I mounted a bunch of magnets on the rim of my front wheel and set coils up in the fork to give me a push.
Getting the phasing exactly right to have any efficiency at all required a faster processor than my MSP430 so I gave up.
Also don't forget to return all the magnetic flux or it won't really work well at all. I don't see that in the patent. I used a little Si steel, too cheap to buy Mu-metal.

I also tried it the other way around, to power my spoke POV LEDs (coils on wheel, magnets in fork) and this worked great except I can feel the magnets going by, I need a carbon frame and non metallic spokes!

Nice conversation going here, I'm glad I found you guys.

Gavin

 

[RoughRider]

the halbach principle is not makeing the motor more efficient...

the halbach makes the magnetic field stronger inside the motor...

BUT...my question is: why there are NO motors with halbach principle on the market?

IS the halbach-principle patented? So, its not allowed to sell motors with this magnet-system?

 

[Toorbough ULL-Zeveigh]

messer halbach discovered/invented the process while working at LLNL, likely they would be the ones holding the patent.
so yeah, anyone building a motor would require a license agreement for the technology.

hmm, if only there was SOMEONE on e.s. that worked for lawerence-livermore who could score a sweet deal like a developers agreement, get access to all the latest research; if only...

u can see why dumpster diving by employees is verboten over there.
there's probably black-tech already just sittin in the trash decades ahead of any the hand-me-down hardware we the public gets to putz around with.

 

[Toorbough ULL-Zeveigh]

Eek. Coker rim? That'll make it "interesting" to try to maintain a constant rotor gap.

isn't it that AF, halbach or not, is supposedly more tolerant of variation in the rotor gap?
but sure, at that diameter wouldn't take much to exceed it's limits.
i suspect the large wheel is used to compensate for the fact that only roughly 1/3 circumference 'fill factor' is possible with this arrangement.
which would be the equivalent of ~20 inch wheel with a full circumference stator just to get enuf usable torque out of it for moving a bike.

now how much torque do u think would be produced from the partial sector of a chain ring?
probably something between 'not a lot' & 'not enuf', but i guess we'll find out soon if a halbach array can perform miracles.

 

[Chalo]

A 36" wheel's rim will be inherently more flexible susceptible to axial runout, but there is a more specific problem with Coker Monster Cruiser rims: They are really crappy. They're rolled steel, lumpy, and inconsistent in both width and roundness.

Something like this Nimbus 36" rim would be better, with only the inherent problems of such a large wheel:
http://www.unicycle.com/unicycle-ha...29-36-inch-rims/nimbus-stealth-pro-rim-1.html

it's aluminum, though, and I don't know whether that would have an effect on the motor's performance.

Chalo

 

[billvon]

New to this site, but not the topic.
Interesting, over a year ago I mounted a bunch of magnets on the rim of my front wheel and set coils up in the fork to give me a push.
Getting the phasing exactly right to have any efficiency at all required a faster processor than my MSP430 so I gave up.
Gavin

I don't think processor speed is the problem. The MSP430 can run at 25MHz. That means you can execute 1000 instructions (which is a _lot_ - plenty to detect a magnet and fire a FET) in about 40uS. At 30mph with 32 magnets on your rim, that's a magnet passing the coil every 2300uS. That would seem to suggest that you have about a 50x margin in timing.

Motor design is tricky; there's a lot to it, and many seemingly insignificant things (like eddy currents, mechanical instability of stator etc) can conspire to make motors far less efficient than you expect.

 

[John in CR]

We've discussed wheel motors on several occasions, and the only real issue was the likelihood of magnetic debris being picked up from the road. Alignment entering the stator section could be aided by some type of roller for perfect alignment. Regarding torque, with that kind of radius, torque wouldn't be an issue. As a practical concern you'd need some way to easily separate the two halves of the stator, or else you be stuck with running tires no wider than the rim.

 

[blues]

And the one really important thing that no one has mentioned yet is that this could actually be heavier than a Crystalyte. Just think, no more worries about going end over end if you lock up the front disk brake on a hard stop...

blues