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?
Yeah, buttons can be found without looking.
They also provide tactile feedback allowing you to be sure they have been pressed without even looking.
THE reason i got a Mazda, after many years of Mercedes and BMW...
Also make them illegal in aircraft! And spacecraft! Seriously stupid.
I vote for cheap PlayStation controllers.
Can we have more mechanical posts like this?
No, you need 555 posts about the shit that a billionaire said about stuff he knows nothing about
And then someone saying something about Linux
Be the change you want to see!!
There's 2 significant inaccuracies in the article and 1 large oversight in the official video.
PS: differentials are irrelevant when the wheels aren't connected to each other. Individual-motor wheels, as shown in the video, don't need a diff. The non-drive wheels in a 2-wheel drive vehicle do not have a differential on the non-drive axle.
Cv joints are not specific to fwd as nearly all modern rwd cars with independent rear suspensions have CV joints. I don't know of any trucks still using U-joints either since big trucks are solid axle. Cv joints function the same as U joints. The difference is C.V. joints output constant velocity whereas U-joints (what you'll see often under trucks on the driveshaft, two square C shaft ends with an X link between) have lopey output that gets worse with greater deflection angle. If you own a u-joint bit for your socket wrench, I invite you to play with it. Instead of a solid pinned X between the U ends, CVs have free-rolling balls that can roll inboard and outboard to maintain the link between the shaft's cup and the wheel's cone.
The article is inaccurate but the video ignores this part, so I don't fault The writer. The CV joints are said to be a poor design, yet, it ignores the part where the video reinstalls them at 4:20 and 5:10 for the front wheels. This mechanism does not allow angular deflection between the motor and hub, as it's shown, without a CV joint. Lateral displacement, yes, but not angular - as in it can't steer. This may be an overall improvement by reducing how often it needs to bend (only when steering), but it doesn't eliminate it. And even then, the rear suspension is still designed to change camber as it changes ride height. Camber is the angle of the wheel as measured top to bottom, as in what you see from looking at the wheels from the front of the car. It keeps the wheels flat on the ground as you lean the car in a corner. You may see an overloaded car's rear wheels look like /---\ as viewed from the rear or ---/ when hanging free on a lift.
Look, I'm not an engineer at Hyundai (or even a competitor) but this doesn't quite pass the sniff test. Cool idea for sure, but it smells a little like marketing is clamoring for something edgy to display. Even as displayed, the motors and original reduces were already very compact and in close proximity to the wheels compared to a normal engine. The slightly reduced footprint of this uni wheel and slightly increased friction of a bunch of additional gears makes me think this is a fractional improvement in practice rather than a revolutionary improvement.
I'd be concerned with the amount of unsprung weight this adds, too. You're basically taking the transmission and adding that mass to the hub. Seems like it would be pretty crashy on rough surfaces.
I considered that but couldn't make any conclusions. The driveshaft and sun gear are not added to the unsprung. I'd guess only half the weight of planets and carriers is added. It definitely adds the weight of the ring gear to the unsprung mass.
I'm also curious how this affects rotational mass. So while every component spinning with the wheel from tire to motor shaft has rotational inertia, small-diameter components such as drive shafts have relatively little rotational inertia. Wheels and even brake discs have a lot more. I don't have numbers obviously but I'm curious if the rotational mass of the ring gear ends up being detrimental compared to a heavier-weight lower-inertia cv setup.
I noticed they conveniently didn't talk a lot about steering..
The claim of "one wheel drive" I think is meant to highlight what happens if traction is lost. It sounds like something I have heard on 4wd off-road forums. I agree the phrase "one wheel drive" is perhaps not a great way to explain the disadvantages of differentials vs limited slip differentials vs locking differentials vs individually driven wheels.
The idea of "one wheel drive" as I have seen it used, is that in a vehicle with one powered axle assembly (what we normally call 2wd-- either front or rear wheel drive) is that if you lose traction with either drive wheel, the vehicle no longer moves because all power is diverted to the slipping wheel.
If you have a limited slip differential, there is a limit to how much power is diverted to the slipping wheel. With a locking differential, you only stop moving if you lose traction to both drive wheels.
Anyway...
The design is really interesting.
You also bring up a good point about how camber changes with suspension position. Also the effective track width changes, such as with my 4Runner which has upper and lower control arms, a Double wishbone suspension. If the motor remains in a fixed position, the wheel will move onboard and outboard relative to the motor depending on suspension location.
I don't quite get how these two effects are addressed with this new design. Or are the suggesting a different suspension technology that they didn't discuss?
As for steering, I wonder if the design rotates the motor along with the wheel. In that case no CV is needed but I would guess there are some downsides to such a design.
I agree the video seems kind of... premature. The mechanism is cool but I don't get the sense that its applications haven't exactly been nailed down yet.
Now thar Hyundai has patented it, it will never become popular enough to impact the market and be standardized in more vehicles or change anything, similar to the Wankel engine.
similar to the Wankel engine
Was the Wankel engine really a step forward though? I'm a gearhead who does all his own car maintenance, up to and including engine swaps in the past and retro-modding bigger turbos and aftermarket fuel injection systems into my cars (Datsuns in the latter case). That being said, I only know the very basics about rotary engines. I've always admired the Mazda RX's from afar.
Mazda, who by no means makes a bad gasoline engine, could never get a rotary motor to last well or to have anywhere near decent fuel economy. Also, the rotary design was tried for a while in at least refrigeration compressor applications, where it blew up there a lot more than the other types of compressors as well.
Yea. They have worse efficiency. To get better efficiency from them you would need to run them hotter (afaik), and if you do that they would last even shorter.
It's great if you want a smaller but still strong engine, but it's not efficient and those seals are a big problem.
The problem with the rotaries is a result of the technology of the time and funding.
They are inefficient because they lose compressed fuel and air as the seals pass over the holes for the spark plugs, which can be largely solved with laser ignition. They are less reliable because of the design of the apex seals, which can be solved by using a roller instead of a blade. Both of those major issues with the rotary could not be solved with the technology of the 60s-00s and the tiny budget available. There are other issues that hold back the design, but those come down to metallurgy and manufacturing processes. Mazda did a great job trying to make the rotary work and it almost killed them.
The other issue that gives then an unreliable reputation is because you can't treat them like a piston engine and people treat them like a piston engine. Hard to fault the knife for breaking when it was used as a pry bar.
But capitalism creates innovation!!!
Some people argue that intellectual property law is not free market capitalism, and is instead a regulation that benefits big business. I'm one of those people
"Probably failed cuz they called it the wanker engine lmao. Now set aside another few milli for the copyright lawyers"
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!
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.
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.
STOP MAKING BIGGER CARS!
If we could get standardized and interoperable electric car parts, that'd be great.
Seems really cool. I will definitely not buy the first model vehicle to use this, though.
Surprisingly easy to understand video for a complex concept.
The explaination of how differentials work was painfully wrong. An I lost confidence in this author's ability to explain the topic.
The one thing they don't really talk about is how it turns. The animations show vertical movement almost exclusively. At one point in the video there is a far shot showing a car turning and it looks like they actually swivel the entire motor to keep it perpendicular to the wheel which if true is going to pretty heavily limit it's turning angle and radius.
For the lazy people out there: https://www.youtube.com/watch?v=Nd6C0y8xc20
If you're gonna go through all this trouble, why not put motors directly into the wheels? Then you can bypass the drivetrain all together and directly power the wheels.
If you put the motor in the wheel you increase the unsuspended mass. Bad for handling and ride quality
Not a new idea, military trucks used reduction gear drives in the wheels before WWII. Edit: Portal Gears.
One downside to doing this is adding unsprung weight, which is not a good idea.
And it will still need a CV at the wheel to accommodate suspension travel.
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.
This is a most excellent place for technology news and articles.
