Aptera wanted to do this with their flagship Solar Electric Vehicle (SEV).
IIRC, they switched to an outwheel motor because of the weight the inwheel motors added to the wheels. Could be wrong tho
Comment on 28-pound electric motor delivers 1000 horsepower
rekabis@lemmy.ca 5 months ago
This looks small enough to be installed within the wheel hub itself. Imagine a car with four motors, one inside each wheel. The entire floor pan could just be one thin battery, and everything above it could be passenger and storage space.
Resonosity@lemmy.dbzer0.com 5 months ago
SaveTheTuaHawk@lemmy.ca 4 months ago
Aptera
LOL. Coming soon…since 2009
Resonosity@lemmy.dbzer0.com 4 months ago
For real lmao
brucethemoose@lemmy.world 5 months ago
That’s how EVs started! Sorta.
But it’s impractical.
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It increases unsprung weight, e.g. weight not cushioned by suspension. Bad for ride/handling/steering feel.
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All that vibration is HARD on the motor. Read: unreliable.
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Motor is more exposed to temperature/dust. Again, reliability.
In reality, a decent suspension needs a lot of room under the body anyway. An axle to get the motor in the body is dirt cheap on the rear, and still pretty cheap on the front, and you could just mount this thing sideways to make it flat…
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Canopyflyer@lemmy.world 5 months ago
That would be a lot of unsprung weight.
Handling and ride quality are dramatically and negatively impacted by every bit of weight that is not held up by the suspension. That’s why higher performance cars will have lightweight wheels. Rather than steel wheels you see on lower performance cars.
It’s better to just put all the heavy drive components inboard on the chassis and run drive shafts to the wheels.
You see motors in the hubs of bicycles, because they really don’t go that fast. So even if the bike has a suspension, it’s not that big of a deal. Motorcycles on the other hand would need to keep any heavy parts inboard.
boonhet@sopuli.xyz 4 months ago
Steel wheels haven’t been common on anything but really cheap cars for a few decades now, but in general your point holds true. There’s heavier and lighter alloy wheels out there.
Still, these could be just tiny motors connected to the wheels via a short shaft on the rear especially. Instead of the huge monstrosities most EVs currently seem to use which are huge, as they also include gearing and such. Still leaves more space for battery without having to go unsprung with hub motors.
lemming741@lemmy.world 5 months ago
Hub motors are a party trick. They will never reach mass market.
boonhet@sopuli.xyz 4 months ago
They might work in the rear if used instead of rear brakes. Rears do far less work anyway and brakes are heavy. Powerful electric motors can do a lot of regen, similarly assisting the front brakes.
avidamoeba@lemmy.ca 4 months ago
They work well on bikes. I could appreciate 1000bhp hub on my 12kg touring bike. 🤭
lemming741@lemmy.world 4 months ago
I agree, they are good for minimally suspended low speed personal transport.
SaveTheTuaHawk@lemmy.ca 5 months ago
Renault 5 RS Turbo has hub motors, Nostradamus.
lemming741@lemmy.world 4 months ago
mass market There’ll be 1,980 of these built
That car is the definition of a party trick. You proved my point, so thank you.
SaveTheTuaHawk@lemmy.ca 4 months ago
Right, because 2000 of something is not mass production.
And here is a source in China definitely not making >20 hub motors for cars, scooters, etc.
brucethemoose@lemmy.world 5 months ago
Renault 5 RS Turbo
That’s because its a limited run show car. Its not meant to be practical.
EtzBetz@feddit.org 5 months ago
German company DeepDrive has some kinda promising tech. And the ID.Polo seems to be said to have hub motors.
lemming741@lemmy.world 5 months ago
Not even the concept had hub motors.
www.autoexpress.co.uk/news/volkswagen-id-polo
electricarworld.com/volkswagen-polo-makes-a-comeb…
auto.hindustantimes.com/…/volkswagen-id-polo-gti-…Limited slip differential? Can’t do that with hub motors. …com.ph/…/volkswagen-id-polo-prototype-a5100-2025…
If you have different information about a production car, please share it. The theoretical concept ID.2 R may use hub motors but that is vaporware at this point.
EtzBetz@feddit.org 4 months ago
I only have german articles. I only heard it in the video source below, and they sadly don’t really say how the normal problems with hub motors would be solved even though they have a section for it in the video.
kylian0087@lemmy.dbzer0.com 5 months ago
Imagine on a motorcycle… Probably nonstop wheely 🤣
KneeTitts@lemmy.world 4 months ago
Probably nonstop wheely
uni-motorcycle
lemming741@lemmy.world 5 months ago
They make sense for scooters, bikes, and other low speed or two wheel personal transport. For anything with an actual suspension (designed for a highway) there is just too much competition for space with brakes and suspension linkage. The unsprung weight, exposed high voltage cabling subject to road debris and accidents are problems too. And what to do hub motors really gain you?
SaveTheTuaHawk@lemmy.ca 5 months ago
Less weight, less parts, 4WD, 4W traction control, more cabin space because no driveshafts.
eleitl@lemmy.zip 5 months ago
Simplicity, no transmission. As to unsprung weight, designs like these have a ridiculous power density, so add only very little. Advanced suspensions are active anyway, so just part of the wheel robot.
vithigar@lemmy.ca 5 months ago
This is already pretty close to how many EVs are designed.
Nastybutler@lemmy.world 5 months ago
Except for the fact that that much power would need massive batteries. So your thin small battery would be dead the first time you mashed the peddle to the floor
IAmNorRealTakeYourMeds@lemmy.world 5 months ago
forgot the part where they were excited to put the batteries on the tire
brucethemoose@lemmy.world 4 months ago
PS
One issue I hadn’t thought of is putting traditional brakes (which generate a ton of heat) right next to the motors. Again, we’re just asking for mechanical issues here, and we’re ballooning unsprung mass to mitigate it, especially in heavier cars that take a lot to stop.
This seems like a minor thing, but the control electronics for the motors takes up a nontrivial amount of space. So do “traditional” subsystems like hydraulics, climate control, or an old fashioned car battery (which often exists in parallel to the EV drivetrain).
Theres also safety to consider. A traditional sedan “hood,” even a small one, is easier on standing pedestrians, so it hits their legs and they flop on top, instead of slamming them like a wall (as a bus/truck front would).