@worsedoughnut@lemdro.id avatar

Fascinating, but in the video they very quickly swipe off-screen that the top speed their new system was able to achieve was 120 kph / ~75 mph.

I imagine something like this would have to be limited to vehicles that never need to approach speeds above that on a highway, so maybe busses or indoor shipping & receiving vehicles.

@ZMonster@lemmy.world avatar

From a mechanical standpoint, the new bearing saves a nearly negligible amount of space. Splitting the motor up and moving it to the notoriously wasted wheel well space is what clears up the center of the frame. Still very cool. It’s basically a single output differential, which is already quite compact. No need to split the rotation for turning since the wheels rotation will no longer be mechanically linked.


But eliminating the long half shaft that accompanies the CV joint is what allows that space to be used.

ZMonster, (edited )
@ZMonster@lemmy.world avatar

I mean you’re not wrong, but without separating the single motor to one at each wheel, you’d still have to translate the power from one point to each wheel. The uni bearing doesn’t provide that benefit. Separate motors DOES. And tuned and articulating short shafts are not a new thing. So even without this new bearing as long as you had separate motors for each wheel all you would have is a short CV shaft between the motor and the wheel. Hell why not save all of the space and just incorporate the motor into the hub??? Since BDC motors are more efficient when wider and smaller, it would be very easy to fit them within current day hubs.

I mean, don’t get me wrong, I honk for planetary gear designs every time. So I’m not knocking this design. It’s simple, machinable, and direct. It’s brilliant for what it is. It’s just not the space saver that they are touting it to be. The video literally showed two seats side by side with a bed in the back. Unless kia started making a suburban, I’m just not that naive.


Having these gears in the hub instead of a motor would decrease unsprung weight.

meekah, (edited )
@meekah@lemmy.world avatar

The gears are necessary to allow the wheel to move without having to move the input shaft.

Edit: sorry, I misunderstood your comment. I agree.

Somehow I thought you’re saying the gears should be attached to the motor.

@ZMonster@lemmy.world avatar

I didn’t think about that. Thanks for pointing it out.

meekah, (edited )
@meekah@lemmy.world avatar

It directly replaces the CV, so it’s the thing saving the space. Sure, if there was still only one motor, and a shaft connecting the two sides, less room would be available. But the space saving, and the reason why splitting the motor in two makes sense in the first place, is the uni wheel.

Also, yes, there are shorter CV joints, but they lose efficiency the shorter they are, because they need to translate through larger angles.

As to why putting the entire motor into the wheel isn’t a great idea for cars is because you want to keep as much weight of the vehicle on top of the suspension. If the motor is in the wheel, ride quality will suffer due to the increase of unsprung weight.

@ZMonster@lemmy.world avatar

Ah, really good points. Thanks for the perspective. My expertise (if I may so generously call it that) ends at the manufacture and assembly processes. Thanks for the perspective.

@meekah@lemmy.world avatar

Honestly, I get most of my knowledge from watching a bunch of youtube videos, so it’s not like you’re talking to an engineer or anything haha

But I do usually like to pick out the more technical videos, explaining the theory behind all this, so I guess I picked up on some things ^^


I cannot think of a car company I’d trust less to do this than Hyundai/Kia.


Somebody better tell them


Hyundai/Kia owners have, in large numbers, told Kia Group about quality issues their cars have. Their usual response is to gaslight everyone until some government agency sues.


No I mean someone better tell them to stop development on the uni wheel because you disapprove


Somebody had* better tell them


I don’t understand how they are going to keep dust and dirt out of it. The point where the drive input goes in has so much movement.


It will have a boot or case on it and will be filled with grease. Just like a cv joint or ball joint.


Then how is it an improvement?


One thing I took from the article is they’re trying to sale the idea of having MORE space in a car due to smaller transmission system. In 1 presentation, they show the idea of putting a FUCKING DOUBLE BED IN THE CAR!

I DON’T want MORE space in the SAME sized cars.

I want the SAME space but in SMALLER sized cars.

The space we have now is FINE, and the car sizes are TOO BIG.



If we could get standardized and interoperable electric car parts, that’d be great.

@ICastFist@programming.dev avatar

Imagine that XKCD competing standards comic here


They have taken us for fools


trying to sell* the idea


So how does it handle potholes?


you didn’t watch the whole video huh?


Video is like the worst possible way to demonstrate something.

I can’t watch a video at the moment as I’m busy not working. I need quiet text thanks.

@viking@infosec.pub avatar

The whole interior setup is flexible and can move around. I’m normally with you on my dislike for videos, but here a visual representation is really helpful. You can watch it without sound though, it’s self explanatory.


Normally I’d agree with you, but the article goes to great lengths trying to explain the concept as text, but it’s damn near incomprehensible to non automotive engineers until watching the video.


For some reason video wouldn’t play on mobile for me, if anyone had a similar issue here’s the link: https://youtu.be/Nd6C0y8xc20


I was just learning about CVJ gearing the other day and was thinking cars should use it instead of fixed gear ratios. Very cool.


It’s still a fixed ratio though?


Oh I was looking at constant velocity transmissions. Similar concept to the uniwheel, as far as the gearing. As least, if I understand it correctly.


When transmissions are discussed, the acronym CV stands for continuously variable. (As opposed to a transmission with 3-5 discrete gear ratios.) But yes, some CVT designs do use planetary gears, especially for hybrid gas-electric models.

CVJ = constant velocity joint

CVT = continuously variable transmission


Thank you for squaring me away, here.


Did none of you watch the video? The article is crap, but the video explains it well.

Go back and watch the video, ya old codgers!

@ZMonster@lemmy.world avatar

I watched the video, but burying a good video under a trash article does not a good sauce make. OP should have just linked the fucking video.


So in short, this adds suspension directly to the wheel, at the cost of higher maintenance? That’s it?


It’s pretty smart. It is like a wheel-motor but without all the unsprung weight.


It’s not suspension. It compacts down the differential and cv joint (linkage from the engine to the wheel).


It compacts the whole drivetrain, from engine to the wheel. The space saving they were showing was mostly from the miniaturization and splitting of the motor.


While increasing energy efficiency and available space, both of which can be used for extending EV range (by adding more batteries that deplete more slowly) - one of the biggest EV issues right now.

Or you could just fit a mini party bus inside a hatchback, whichever you prefer.

To your point though, one of the othe big EV issues is cost (both purchase and maintenance) - even if a large chunk of it is artificial. Wonder what the price tag and lifespan on these things will be.

@OminousOrange@lemmy.ca avatar

EV maintenance cost is quite low compared to ICE vehicles. Brakes and suspension are probably the biggest wear items, but brakes have comparatively less wear because of the regen braking.

nexusband, (edited )
@nexusband@lemmy.world avatar

Nope - the ~~ADAC ~~ (turns out, i was wrong about that) GDV in Germany did a study a few weeks ago and they found EV maintenance is actually higher, because parts are so much more expensive and also brakes are needed a lot more regularly. However, the last one could be just a german problem, because of our TÜV. Edit: gdv.de/…/studie-e-autos-sind-bei-der-reparatur-ei…


Could you link the study? The article I saw last week was just about the quantity of unplanned issues, with the overall cost being much lower for EVs. If you could link it we can compare and see if we’re taking about the same thing.

@nexusband@lemmy.world avatar

The article talks about the cost of “repairs”, not “maintenance”. Those are two different things.


Yeah you have to look at lifetime cost

@OminousOrange@lemmy.ca avatar

How are brakes needed more regularly? Most of the braking a normal driver would do is done by the motor(s). Sure, the vehicle is heavier than a similar sized ICE counterpart, but I would guess a typical driver is using one-pedal driving whenever possible. Anecdotally, I have an Ioniq 5 and brake almost exclusively with regen, whether it’s I-pedal, or shifting between the four levels of regen when decelerating from higher speeds.

@nexusband@lemmy.world avatar

Because they rust when you not use them and always use regen. And most BEV drivers do not “maintain” their brakes, as they do not brake more vigorously to free the rotors of rust. There’s a limit as to how much wear/grooves your disc can have and at least for many Teslas that’s one of the reasons why they fail their first TÜV check up after 3 years. (Not to mention the horrible quality of Tesla suspension and chassis components…)


You can’t always use regen as it doesn’t stop the car quickly enough in many cases. From my own experience, regen probably gets used about half the time when braking.


Volt owner checking in. I do one pedal driving 95% of the time and you’re right. My brake disks are in rough shape because they see so little use.


That study says nothing about maintenance but is about repair cost after accidents. Those are 1/3 higher for EV because also small damages to batteries can increase risk of fire and batteries are also more readily exchanged due to lack of experience of the shops.

Everyone is talking about breaks while the study doesn't say anything about that.


Air conditioning and touchscreens didn’t alter how cars drove but did revolutionize the driving experience.

Can we please make touchscreens for neccessary functionality illegal, like using phones while driving?

@HiddenLayer5@lemmy.ml avatar

Or at the very least, do what modern airplane cockpits do and have a trackpad/trackball on the center console.


So much this, it makes no sense for using a portable phone to be illegal while driving but yet my car stereo can be a full on entertainment system and require me to have zero feedback to change the channel or answer a call.


Also make them illegal in aircraft! And spacecraft! Seriously stupid.


I vote for cheap PlayStation controllers.


Weren’t they using an Xbox controller for that Titan sub?


No it was a PC controller in the form factor of a PlayStation controller


It was a Logitech F710.


Should have used a madcatz controller, then they would have had a turbo button.


Also make them illegal in aircraft

Salty Boeing


I suppose the advantage on aircraft and spacecraft is that they consolidate functions so you don’t have to have 90,000 switches in the cockpit, half of which you won’t ever need.

Anything you need to find in an emergency absolutely should be a physical switch but anything else can probably be a UI interface.

But in the car you need to keep your eyes on the road at all times, which isn’t so much of a requirement in the air.


I can’t think of a switch you won’t ever need. I think the “sce to aux” story is a good example of when you need it you need it.


If you can consolidate the UI to make it with work with touchscreen, you can make it work with something like Keyboard + trackball mouse and you can get rid of that touchscreen. I know it’s not the same stake situation but have people forgotten how much functionality blackberry had with QWERTY and few more buttons. Shame that the company went out the way it did

@nexusband@lemmy.world avatar

THE reason i got a Mazda, after many years of Mercedes and BMW…


I feel like not enough people realize how amazingly simple and tactile the rotating dial is for doing anything in a car. And especially the placement being down by your arm makes it so easy. I can feel where all those buttons are without taking my eyes off the road.


Yeah, buttons can be found without looking.

@HiddenLayer5@lemmy.ml avatar

They also provide tactile feedback allowing you to be sure they have been pressed without even looking.


My parents’ Lexus has a button joystick kind of thing with similar resistance tech to the ps5 triggers for the navigation. It’s not bad.

The joystick is on the center console, so you can use it without looking.


How do you see what the joystick is pointing at without looking at the screen it’s controlling.

Radio volume, climate controls, and drive/transmission controls are all necessary for safe operation and should be able to be used without taking eyes off the road if needed. There should be federal mandates to keep those controls off of gaze required touch screens. (I’m looking at you VW, of which I own 3 classic examples, but would never consider a current gen one).


I think it’s just for changing inputs and radio, not climate, definitely not volume or transmission. You do need to look at the screen though.


I’m pretty sure they are for safety critical controls, such as in an aircraft cockpit. In the automotive world, we like to keep it jazzy and smooth, like my romantic life.


They aren’t. Light ircraft now use touchscreens that you are supposed to use while bouncing around. They had a knob for a while but then it seemed touchscreens took over. With the knob you still had to look, it at least you didn’t have to aim at a bouncing spot on the screen.


Oh wow, you guys get the cool stuff too? That must add some much need spice to the humdrum activity of controlling a potentially lethal machine.


I don’t get what this does or what’s the benefit. There’s still a cv-joint there. Otherwise the wheels can’t turn


It’s a bit overcomplicated wheel reductor hub, used in some trucks and widespread in heavy equipement, but the input shaft can move a bit. And the artictle doesn’t mention anything about oil in it or how it is sealed.


The motor could move with the wheel, but there goes that space they saved.


It replaces the cv joint. Watch the video.


There’s the CV-joint



The video shows how their gears go up down and side to side to perform the function of a cv joint. So whatever that cv looking thing is, it’s not a cv joint.


If it was just a solid axle going from the motor to the uniwheel you couldn’t steer the car. It doesn’t allow for such movement.


The motor could turn with the wheel. You could have a wheel-motor without the excessive unsprung weight of the motor components.


Looks like it eliminates the engine-side cvd but not the wheel-side.


Can’t really do that, u-joints and cv’s work in pairs to balance the angular change


There is no angular change between the axle shaft and the engine.


This is pretty cool!

But, in the video there is a quick flash of text that went away after 1s, 120km/h max speed?


they’re probably going to improve it further

@PlutoniumAcid@lemmy.world avatar

What a badly written article, wrongly explaining both the diff and the CV joint. That’s not what they do or how they work.


Yeah, skimmed and saw one of his other articles praising the cybertruck and realized this likely wasn’t a source worth absorbing.


EV already have much smaller gearboxes, because they don’t need to shift.

Now they need 4 of them, not just 1.

Such a gain in weight :-)


This isn’t a gearbox. It’s a means of transferring power to the wheel, while having the electric engine sitting right next to the wheel.


This isn’t a gearbox.

Then it’s the replacement for one.


No not really either, at least no more than the gearing in an electric car is a gearbox.

A gear box deals with shifting between different gearing factors. This isn’t the case here. Yes, the pace of the engine is geared, fixed, to the pace of the wheel, but that’s the same in many electric cars. Some are connected directly to the wheels but many have a fixed gear.


at least no more than the gearing in an electric car is a gearbox.

what I said, smartdonkey.


Ahhh, now I get your original comment.

My apologies, you were right and I was wrong. I didn’t read your original comment well enough.


Respect upvote. Can we have this be our culture in Lemmy?


Article made it sound like only front wheel drive exists now and that only front wheel drive cars use CV joints lol.

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