this post was submitted on 02 Dec 2023
713 points (93.0% liked)
Technology
59657 readers
2914 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
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.
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.
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.
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 ^^
Having these gears in the hub instead of a motor would decrease unsprung weight.
I didn't think about that. Thanks for pointing it out.
~~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.