Alternative to CV Joints - “Uni-Wheel”

[jyl]

https://cleantechnica.com/2023/11/30/behold-the-hyundai-uni-wheel-transportation-may-never-be-the-same/amp/

Scroll down about halfway to see the Hyundai video.

My questions:

- Won’t the gears have to operate in a sealed chamber, if not in a oil bath, to
survive automotive duty cycles?

- What is the tolerance for change in angle between the input shaft and the plane of the well?

- Does torque produce any squat/dive effects anywhere in the wheel’s travel? How about reverse torque (wheel braking)?

[flatbutt]

Isn't that 9 points of failure per wheel?

[Alan A]

Looks like one of those gear driven timing chain forerunners - but bendy…

[oldE]

Unsprung weight and at no point in the video did they show how power gets from the electric motor to the hub during a steering input. Have fun sealing that system. Ferdinand Porsche was a century before his time.

Notice they did state the efficiency of cv joints diminishes with increases in angle of operation. This is not that big of a deal in most applications as most passenger vehicles spend the vast majority of their time with very little deflection.
The end of the article mentioned specific use vehicles. I can see this system being useful for fork lift trucks mining equipment and other applications where you need all power available in tight turns at low speed.

Best
Les

[porsche tech]

Pretty cool engineering feat…but I thought the same thing as previously stated: lots of expensive stuff to wear and possibly fail.

[LEAKYSEALS951]

I'll keep my no good stinkin' rock auto CV joints thankyou!



Reminds me a bit of a sturmey archer 3 speed bike hub. Incredibly neat on the inside, but inefficient, and those little teensy gears would brake of you really abused it.

[oldE]

I noticed they didn't show any kind of brake in their animation. I suppose they are expecting to use re-gen for braking.
My question would be: if the motors are getting so compact, why not put them in the wheel, a la Dr Porsche's old design and get rid of all the machined moving parts. They illustrate jounce and rebound as well as some fore and aft displacement of the wheels but their design would still require some device to allow yaw of the wheels so one could steer.
The device as presented solves nothing for the majority of automotive applications.

Best
Les

[GH85Carrera]

It certainly looks more complicated and expensive to make. Is it a solution looking for an application? The basic CV joint has been tried and tested for billions of miles on millions of vehicles.

[LEAKYSEALS951]

Originally Posted by oldE

Have fun sealing that system.

It will undoubtedly be a "lifetime fluid", and no drain port will be provided.

[TimT]

Its really nothing new, hub drives have been used on heavy equipment for ages..

https://www.dana.com/globalassets/markets/off-highway/downloads/dspcorp00017-h-series_specsheet_a4_en.pdf

[oldE]

They show two additional areas which would have to be sealed. The perimeter between the suspended hub plate and the driven wheel hub shouldn't pose too much of a problem. The plane between the hub plate and the shaft carrier represents an challenge in that the relative motion is in two dimensions.
Not only "No", but "Heck no!"
The guys who thought up this load of crap should be made to sit beside a technician whose job it would be to remind them of real world conditions.

Reading my comments on this thread might give one the idea I don't think much of the concept.
Good thing there are lots of clouds to yell at today.
Best
Les

[GH85Carrera]

In specialized heavy equipment like a D-11 bulldozer size equipment it may be useful.

For the average car, I don't see it is a viable replacement for the inexpensive and well tested CV joint.

[john70t]

Um the wheel hub constantly turns and changes castor and camber.

How does that design allow vector changes between a fixed driveshaft and a hub moving on three planes?
Maybe I'm missing something.


(that website is almost unreadable with the same ad every paragraph)

[Bill Douglas]

Originally Posted by flatbutt

Isn't that 9 points of failure per wheel?

My thoughts exactly.

Great for the first 100,000 miles (maybe not even that) then some poor fella has to try and rebuild it. Or pay a bomb to buy new ones.

[Zeke]

I missed how the shaft steers too. And camber change, how is that accommodated?

AFA placing the motors IN the wheels, that increases unsprung weight. So for that matter, all those gears and housing must mean something.

[john70t]

Originally Posted by GH85Carrera

Is it a solution looking for an application?

This. Perhaps a belt or track system? IDK.
It's a neat concept but not the droids we are looking for.

[LEAKYSEALS951]

In the video it appears there are still CV joints on the front for steering.

I went to the youtube site, expecting to read some snarky comments. Instead everyone was raving about it.

What is the world coming too? You can pry my old torn cv joints from my cold dead body!

[cockerpunk]

Originally Posted by john70t

Um the wheel hub constantly turns and changes castor and camber.

How does that design allow vector changes between a fixed driveshaft and a hub moving on three planes?
Maybe I'm missing something.


(that website is almost unreadable with the same ad every paragraph)

yeah doesnt solve the CVs job, which is angular.

this is just like a watts linkage or panhard bar in a differential.

[David Inc.]

"Yes alignment shop I would like to adjust my camber and toe."

"No."

[TimT]

n that video they didn't show any upper suspension control arms etc.. they highlighted the in wheel hub drive..

So yes toe,caster,camber can be adjusted