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Hyundai Uni Wheel electric drive system could revolutionize EV design

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Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#81

Post by chakintosh »

hooby wrote: post #47

The thing I see not mentioned in the article/video, is how the wheels can tilt/turn/angle - without needing a CV joint again. The designs seems to cover all the motion of the wheel in the suspension - but I don't see how this could accommodate steering. Is this for back wheel drive only? Curiously the animations shown in the video, show the uni wheel used in the front of a front wheel drive car - but without ever sho…

In the video there was a brief animation at 5:06 showing the entire motor rotating with the wheel. So the CV joint (if you can call it that) wasn't really removed, just moved to the part between the motor and the chassis.

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#82

Post by jacquesm »

Beijinger wrote: post #80
jacquesm wrote: post #79

Earlier quoted context omitted.

That you save on a whole bunch of linkage and drive train components, four wheel drive without the associated complexity, that you can integrate the wheels, motors and brakes, cleaner airflow under the car and that the system as a whole can be lighter weight than the same package with motors near the centerline of the car, so you get somewhat better range. It also gives more space for batteries and/or more storage sp…

"cleaner airflow under the car"? Why should the airflow be cleaner?

Because that's automatically better range, cleaner airflow is less drag. That's why cars have all of those underbody skirts, it improves their mileage (and helps with not fouling up the more sensitive bits).

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#83

Post by KaiserPro »

I love innovation.

There still needs to be a CV joint to allow steering, but short of hub motors[1] There isn't much you can do about that.

What I would be interested to see is how lubrication works. Do you think they just have a bunch of oil in the bottom and rely on centrifugal force to fling it to the ring gear? Then let surface tension transmit it to the sun gear?

[1] They are heavy and heavy wheels affect ride quality, as suspension works essentially by allowing a light wheel to move up and down dampening against the mass of the heavy body. If the body is light, then you need to have less dampening, which means more shock/impulse is transferred into the main body of the car/

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#84

Post by JoeAltmaier »

konart wrote: post #59

I wonder how long will it take this to break if use on real (not-so-perfect) roads.

My first thought, too. All those unsealed tiny gears. One fragment of metal filing in there? Perhaps a cascade failure of teeth chipping and flinging fragments until total breakdown.

Reminds me of the head of a waterpic toothbrush - a packet of tiny gears, the weakest point in the device, constantly wearing out.

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#85

Post by JoeAltmaier »

trabant00 wrote: post #49

Unsprung weight is a clear disadvantage to the solution. It will significantly affect ride quality, no way around that. Those planetary wheels look more fragile than the traditional solution. You also need to keep that entire thing closed and lubed as well and even so it looks like added friction, wear and a more expensive repair job when it goes bad. All that being said it could be a good niche solution. A small cit…

At least they are nine identical gears? So just keep a barrel of them handy!

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#86

Post by dist-epoch »

benj111 wrote: post #65
husam212 wrote: post #56

Earlier quoted context omitted.

Maybe the motor is supposed to turn with the wheel, that doesn't sound like a good idea.

Why not? You'd have an added complication of making the shock absorber the pivot point, and attaching the motor to the top point. Or having a separate pivot point where the motor or wheel can slide up and down. This does raise the question of why not just attach the motor straight to the wheel. The standard response to that is a hand wavey "unsprung mass". But has it actually been tried and shown to be an issue?

I'm no mechanical expert, but I wonder how you prevent damage to the motor if the wheel encounters an obstacle when it tries to rotate (against a curb for example) or if it's forced to rotate by an exterior force.

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#87

Post by zardo »

estiaan wrote: post #45
ChumpGPT wrote: post #37

Earlier quoted context omitted.

An ice could use this but there is no real purpose. The whole goal was to make the electric motor smaller and closure to each wheel so there is more room for other things.

Yeah fair, though ICE cars also benefit from more space. Maybe I’m just salty because I had to watch 10 minutes of their video just for a clip that was about 1s long that actually shows what it is instantly, they should have lead with that…

You probably don't want to use a small ICE at each wheel though.

Re: Hyundai Uni Wheel electric drive system could revolutionize EV design

#90

Post by tlb »

benj111 wrote: post #65
husam212 wrote: post #56

Earlier quoted context omitted.

Maybe the motor is supposed to turn with the wheel, that doesn't sound like a good idea.

Why not? You'd have an added complication of making the shock absorber the pivot point, and attaching the motor to the top point. Or having a separate pivot point where the motor or wheel can slide up and down. This does raise the question of why not just attach the motor straight to the wheel. The standard response to that is a hand wavey "unsprung mass". But has it actually been tried and shown to be an issue?

Unsprung mass sucks. You don’t notice on smooth surfaces, but if you are cornering on a rough surface the wheel ends up losing contact with the ground after each bump. It’s extra-dangerous when its the rear wheels because the car can spin out.
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