Protean electric hub motors in 2014

[oil pan 4]

Why no hub motors?
Well my nissan leaf makes 236 foot pounds of torque, depending on who you ask the single gear drive reduction is between 7.9 and 8.1 to 1.
So 236 times 8 equals a lot more than what you get from 2 hub motors.
I guess if you actually use your electric car only as a grocery getter you would be fine.
But my electric car does more than most pickups. So I will keep my roughly 1,900 foot pounds of torque.

Has anyone actually released a hub motor driven mass market car?

[Piotrsko]

There's a goofy Russian guy over on diyelectric cars that has interesting mods to hub motors, but belongs in the corral. Hmmm, haven't seen him post in avbout 3 months.

Net result: lots more torque, efficiency, but still relatively vapourware.

[oil pan 4]

The only way you could get more torque, not necessarily lots more torque is to put a hub motor on each wheel.
But that would be hundreds more pounds of unspiring weight and at least double the weight of drive system.
I don't know if it would work that well.
It may but since it seems like every major manufacturer has tested them and no one has brought one to production that may be your answer.

[kach22i]

I cannot seem to find it right now, but about 15 years ago Ontario Hydro put some electric hub motors on a Chevy Caprice - one of the big ones from the early 1990's.

They got a grant to promote electricity usage via promoting electric cars I think.

From all accounts it was very successful, but there was no follow up.

I think that I heard about it on NPR, but don't remember it was so long ago.

[Stubby79]

My 250w geared ebike hub motor has more torque on takeoff than my 500w gearless...less top end power, mind you...but I don't see why they couldn't do the same here.

[aerohead]

Originally Posted by YeahPete

I wouldn't build a new vehicle with hub motors, but to retrofit an older car with them sounds like a good idea. I am also under the assumption they will be lacking in power. I am no expert though maybe they will prove me wrong.

A lower-powered,heavier Ev will out-accelerate an ICE vehicle,due solely to the torque characteristics of an electric motor.
They'll get three times the fuel economy as well,on a Btu/kW basis.

[redpoint5]

The thing is, there's no reason to make the engine into the shape of a wheel. It's neat, and 4 wheel drive is a nice plus, but forcing the design into a particular shape, size and weight means making compromises. Better to build an efficiently shaped, sized and weighted motor, and connect the output to the wheel. This reduces unsprung weight too.

Perhaps they are cheaper to produce than a motor, gears, differential, and axle? If so, they make sense in lower performance EV applications, but when competing against ICE vehicles, EVs need every performance advantage they can get. Certainly it's not cheaper to make 4x hub motors than 2x electric motors and associated drivetrain.

[oil pan 4]

Originally Posted by aerohead

A lower-powered,heavier Ev will out-accelerate an ICE vehicle,due solely to the torque characteristics of an electric motor.
They'll get three times the fuel economy as well,on a Btu/kW basis.

Not if it has 4 hub motors, it will have less torque and about 400 more pounds of rotating mass.

[gone-ot]

Would be great for "vectored steering" control being able to control EACH wheel separately.

[redpoint5]

No reason why you couldn't have 4 motors connected via driveshaft to 4 wheels. The advantages to not having the motors double as the wheels would still be there.