251–260 of 362 posts
For family cars we need 4x 30-50 hp units. If the motor can weigh around 7 kg it can be placed directly on wheel. Adding durable brake discs (rarely used) and 2 inverters front ad back and we have the EV platform of the next 100 years
Personally, I'd rather see FWD with 1 100HP motor in a 2200-lb 4-seater under $20K US, but that will never happen as the supply is artificially constrained to create high-end cachet.
Earlier quoted context omitted.
Electric engines are already very efficient (particularly compared to internal combustion). If you go from 90% to 95% efficiency, you don't save much in terms of battery. ETA: Internal combustion engines half a century ago had an efficiency of 20%, now they're at 40%. That cuts the fuel you need to carry in half. Electric engines are near 100%, and as I said, going from 90% to 95% efficiency cuts required battery by…
Going from 90% to 95% efficiency you're halving the thermal loses, thus reducing the need for cooling by half. It's a big deal. Same with going from 99% to 99.5% efficiency. It still reduces the cooling needed by half.
But the motor is not the only thing that needs to be cooled. It’s mainly the battery, which has a narrow operating range. The power electronics that convert AC to DC also need to be cooled.
So you’re halving the cooling needs of the motor, which is nice but small compared to the other two. And even then, total cooling doesn’t impact range that much compared to warming the battery in cold climates.
I think you’ve overstated your case.
For family cars we need 4x 30-50 hp units. If the motor can weigh around 7 kg it can be placed directly on wheel. Adding durable brake discs (rarely used) and 2 inverters front ad back and we have the EV platform of the next 100 years
do we need disk brakes?
Earlier quoted context omitted.
I was curious how this thing works and asked Claude to visualize it -- mostly to see how good Fable is and I have to say, what it made was good enough for me to get a gist of it. Posted it here https://azimi.me/axial-flux-motor-explainer/
This viz is superficially neat, but hard to get info out of. It seems like a demo in a movie. What did you like most about it?
It’s possible to actually learn something from this, whereas the one fable created is just slop with pretty colours.
I would guess that hydro and other generator forms would benefit from this design as well? Personally I’d love to see this make it’s way into power tools and CNC motors.
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> n early 1900s ICE is considerably worse than a 2000s ICE. But how much worse is a early 1900s electric motor from a modern one? I can't find data, but I suspect the first electric motor from the 1830s is more efficient than a modern ICE (even if we assume the ICE is built for efficiency, screw emissions). There is some room for improvement, but there isn't much difference between our best motors and perfection (a c…
Early electric motors were awful , because there was no good way to control their speed. For example, DC motors used in some late-1900s trains still had a giant variable resistor in series with their motor, burning away a huge chunk of the power as heat to force the motor to run at a lower speed during acceleration. AC motors weren't much better. Electric motors only became truly efficient when variable-frequency dri…
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The Chinese EV industry is actually lead by development of batteries , especially CATL. Along with the pack engineering, which is good old Mech.E stuff about heat transfer and physical strength. Secondarily power electronics; at that scale, you can't just pick a bigger transistor and call it a day. By comparison the motors seem to be a mostly solved problem, although I'm sure there's still some scope for power-to-wei…
> The Chinese EV industry is actually lead by development of batteries This is the core point, but it applies for the whole of the industry. Motors just don't matter. An electric motor is an almost vanishing component of the weight and complexity of an electric vehicle. Cut the mass of the thing *in half* and you're looking at 100kg savings, tops. You could do that with a Model Y by just changing the roof material to…
We have a dual-motor EV and our lease is expiring this year. We have our eyes on the GLC EV, which will land in the U.S. with a tri-motor design at first. There’s no fun in a single-motor EV.
Unfortunately, most modern engines are transverse mounted. They can fit any transmission with an adapter plate, but then they're set too far back into the firewall to access stuff like the high-pressure fuel pump (which is often mounted on the transmission side for easy access on front wheel drive vehicles). I feel that's by design for planned obsolescence.
So I really wish that someone would offer a 4-6" thick 100-200 hp (100 kW) axial flux motor insert between the engine and transmission. Optionally with a simple battery management system (BMS) storing perhaps 5 kWh to provide up to 15-20 miles of electric range and hybrid fuel economy with regenerative braking.
If anyone knows of one, please let us know! If not, then those of you who won the internet lottery could make a killing investing in a novel product that everyone wants but doesn't know it yet.
For family cars we need 4x 30-50 hp units. If the motor can weigh around 7 kg it can be placed directly on wheel. Adding durable brake discs (rarely used) and 2 inverters front ad back and we have the EV platform of the next 100 years
Motors in each wheel eats tires. Personally, I'd rather see FWD with 1 100HP motor in a 2200-lb 4-seater under $20K US, but that will never happen as the supply is artificially constrained to create high-end cachet.
Earlier quoted context omitted.
Yes, you must be able to stop independently in the case of some kind of total power failure in the drivetrain.
Can regen brakes keep a car stopped? I would think that the braking force diminishes as the rotor speed approaches zero so it wouldn’t keep you in place on a steep hill, but I’m not sure.