Magic Pie IIII

[Who42]

Lets think outside the box for a minute the Magic Pie IIII can GOLDEN MOTOR make the next generation hub motor the most efficient in the world . Think they can achieve over 98% efficiency.
How buy a radical rethink on how a hub motor is made. see Pics

[Sam.Vanratt]

Hi Who42
I've already seen this design type in bigger BLDC (automotive) to achive highest Power/size ratio which is needed for highspeed cars like Lotus Lightning GT. Problem with all hub motors is it unsprung mass. Even with the big advantage of direct drive (active steering) 1/2/3/4 wheel drive, redundancy, recuperation) it's quite uncommonly used in cars (which are the "driving motor" of BLDCs atm).
The MP3 already weights 6,5kg compared to about 78% efficiency; BionX can get 76% by 3,2kg weight. Putting much more rare earth and copper (they could use aluminium coils as well and safe weight) into the outer rim gives torque, but centrifugal mass makes it very difficult to accelerate/decelerate. The torque is atm a problem for all bike fork manufacturer already as you can see in my posts about forks...
And I have not seen anything innovative from mass manufacturing. LRK Motors (like the Bionx or SP, MP1/2/3 from GM) are quite old in invention (around 1990), but needed 10 years before it was used to the availability of hi capacity/longevity accu's.

Another interesting motortype is the Trans Flux Motor which has an efficiency around 85-90% without adding additional weight, just thestructure is much more work intensive and the electronic quite fast which limits it's use to big & high power like Transrapid railway.

Best wishes
SAm

[Who42]

CSIRO originally designed this in-wheel motor for the Aurora 101 solar car. Its now used buy most of the teams Its now won most of the races

This particular car raced in three Darwin to Adelaide World Solar Challenges, winning in 1999 and coming second in 2001. Aurora still use CSIRO's motors in today's racers.

Our solution
This motor achieves 98 per cent efficiency and is generally accepted as the most efficient in solar car racing. It has a low active component weight (6 kg), and a total wheel weight of 14.5 kg (including the tyre).could acheave over 100km/h at 1000w

In-wheel motors used by other teams typically had energy efficiency less than 95 per cent and weighed twice as much -- not including the wheel and tyre.

CSIRO's in-wheel motor is widely regarded as the most efficient in solar racing.Other features of the CSIRO design were that the motor was no wider than the wheel (to minimise aerodynamic drag) and the motor's light weight enabled a single front wheel to be used, which again minimised aerodynamic drag.

Downloads
http://www.csiro.au/~/media/CSIROau/Divisions/CSIRO%20Materials%20Science%20and%20Engineering/InWheelSolarCarMotorTechDetails_CMSE_zip%20Standard.zip

[Sam.Vanratt]

Hi
I think that's a different start. When I worked for the Tour de sol in swiss (around 1990) we used high efficiency products only; why? They've been the only which could provide the possibility to be solar only. The prices have been exaggerated just like now: the lightest, the strongest, the high end. But such products never reached consumer market, no question which one produced it.
Maybe GM may look upon, but I could not imagine more than a few produced. The precision to create it is very high; nothing for the mass production. If you look on a 6kW Plettenberg BLDC and on a high Power HPM5000B from GM you will see big differences. The price is about 7 times higher, the efficiency is starting with 75% and ends around 96%, the stator is soldered and the package glued, the clearance (between the magnets and the coil) is about 500% closer (which needs exact measures and special material for close similar thermal expansion), the bearing top notch.
I like GM because they build interesting technology at an affordable price.
But maybe I'm wrong and GM "hears" your voice
Best luck
Sam

[Sam.Vanratt]

Hello Who42
did you get any more response, maybe GM itself?
Cheers
Sam

[Morgen 3Eman]

Hi Sam,

I just read the thread, regarding the CSIRO motor design and I noticed you said  "The precision to create it is very high; nothing for the mass production."  I hope I don't get in trouble again for disagreeing with someone, but I don't think high volume manufacturing of this motor type would be any problem at all for Honda, or some other company with a similar attitude towards quality control.  I agree that  current GM management couldn't pull it off, tho.

TTFN,
Dennis

[Sam.Vanratt]

Hello Dennis
Honda is (as automotive mostly) not the mass mfc I'm talking about. If you compare the chinese cheap cars to high class japanese cars there's a big gap. CN could mfc much more and drop quality at the same time. The CSIRO (I read in 2004 about it when I stumbled upon the LRK principle, which is linked there) is build around a framework of high precision building and quite unusual coils.
In automotive one key is clearance (here "Spaltmaß"). Mass production means getting something done in high volume AND cheap (so it could be sold to the masses). Low tolerances and high time consumption does not apply to mass production and mfc'ing 1k/day is not mass mfc. 100k/day of the same spec (like mainboards or iphones) and low loss is mass production, but low tolerance mostly is not.
I do surely agree with your quote, so we are still alligned here.
So much I have seen GM products (which is none compared to what e.g. Gary knows and have seen) such products would not fit into such a scheme. But I'm open to surprises :-)
Cheers
Sam

[Morgen 3Eman]

Hi Sam,

I was using Honda as an example of the manufacturing precision that is commonly seen around the world in large scale production.  I used to be in the semiconductor manufacturing business, and we used to routinely place overlaying patterns within a few hundredths of a micron.  I still do some consulting troubleshooting for an Intel manufacturing tool, and they are now placing patterns within thousandths of microns.  They understand that precision manufacturing increases yields which equals profit.  By reducing variation within one particular step of manufacturing it allows engineering staff to find other sources of variation in differing steps.   GM just hasn't figured out how to take advantage of quality improvement.  Just glancing at some of the photos I have seen on messages on this board you can see some ugly, easy to solve quality problems.   

TTFN,
Dennis