Donut Lab's next-generation in-wheel motors
donutlab.com
Donut Lab's next-generation in-wheel motors
1–10 of 41 posts
Re: Donut Lab's next-generation in-wheel motors
#2At first I was like "this is crazy, those are going to be crazy expensive, they'll never make it" and then I realized we're not the customers, at least not willingly
Re: Donut Lab's next-generation in-wheel motors
#3At first I was like "this is crazy, those are going to be crazy expensive, they'll never make it" and then I realized we're not the customers, at least not willingly https://www.donutdefence.com/
The Oruga Unitrack [1] is listed as one of their case-studies, it looks awesome and I would really like to see it move.
I found [2] on YouTube, but it doesn't seem to contain any actual video of the vehicle (and the voice-over says "unit-rack" rather than "uni-track" which I didn't love).
Re: Donut Lab's next-generation in-wheel motors
#4At first I was like "this is crazy, those are going to be crazy expensive, they'll never make it" and then I realized we're not the customers, at least not willingly https://www.donutdefence.com/
Looks like they're targeting "civilian" products as well https://www.vergemotorcycles.com/
Re: Donut Lab's next-generation in-wheel motors
#5Looks like one of many "shovels for gold diggers" unitized motors for robotic dogs and humanoids. There's been a lot of such compact all-in-one motor units from China lately.
Re: Donut Lab's next-generation in-wheel motors
#6I spent a number of years designing outer-runner direct drive permanent magnet motors for industrial equipment and I've got some questions.
Cheifly, bearings. They're not shown in any of the oh-wow images, but these will likely be the most expensive component of each motor. Big bearings are expensive, and to accept the loading of normal wheel operation, these will have to be pretty beefy. That's not even discussing operational life and maintenance.
After you've stuffed a pair of angular contact roller bearings into this "wheel", you're going to want to keep salt water and road grime from entering those bearings, so what do you use as a seal? Whatever you use is going to be big, expensive, and suck up huge amounts of power due to the large contact surface.
Finally, once you've got big ass bearings and big ass seals, how do you have enough room to put a decent amount of copper in there? Power in these things always amounts to maximizing the amount of copper in the space, and I just don't see room for it.
Re: Donut Lab's next-generation in-wheel motors
#7I guess I'm not really following. The engine's in the wheel?
Re: Donut Lab's next-generation in-wheel motors
#8Maybe they thought of this, but I didn't see any mitigation for the unsprung mass problem that these motors bring.
Re: Donut Lab's next-generation in-wheel motors
#9Maybe they thought of this, but I didn't see any mitigation for the unsprung mass problem that these motors bring.
If the weights are listed on the are to be believed, this shouldn't be an issue. It says 40 kg for a 21" wheel. A quick Google is telling me that a regular old steel wheel from a truck of the same size is around 50 to 80 lbs (23-36 kg).
That said, I was already thinking 630 kw per wheel was a pretty incredible claim before I realized these are apparently not much heavier than a non-mptorized wheel. These have to be some marketing department numbers or something. 630 kw is roughly 850 horsepower.
Re: Donut Lab's next-generation in-wheel motors
#10I guess I'm not really following. The engine's in the wheel?
Yeah. In fact, the article linked below[1] is more informative than the page I linked. TL;DR: there’s a big reduction to the overall weight of an EV using these, but they do add to the unsprung mass of the vehicle (the weight below suspension, as mentioned in another comment).
[1]: https://www.cnet.com/home/electric-vehicles/this-donut-shape...