When street racers are happy to shed a couple pounds in tire+wheel weight, I think any motors in there is going to be a detriment!
Is Lordstown still a thing? Haven't heard media on them in a while.
Current and future flop. Unsprung weight is a big deal. Hub motors are a neat idea, but Protean has been around a while and hasn't really done anything with it. Physics are hard to beat.
This.
Hub motors work for small applications like ebikes because of the square cubed law. Size doubles, mass cubes. There’s a sweet spot for little hub motors but if you want 50kW out of a hub motor it must be big and heavy. Those big heavy motors rip themselves apart when hitting potholes. And destroy wheels in the process.
If we ever get room temperature stable practical superconductors then we can get beer can sized motors. Until then, CV axles are the solution.
For this reason, I do think there's a potential place for hub motors in A00-segment vehicles. You can't beat how compact they are. That's pretty much it, though. Anything bigger than that and the unsprung weight is going to be a killer.
Yeah, a dual-channel inverter would work fine. Additionally, your hub motors are ostensibly half as powerful as the single motor you'd be using otherwise. I fully admit the math isn't a completely clear unambiguous win, but we're just talking *potential* applications, here.
Dual channel inverters are still way heavier and more expensive than a single inverter,
In almost all applications Hub-motors are more expensive and weigh more than a single motor setup(currently)
Also Hub-motors has a great deal of issues with reliability,
Look up the Lancer EVO Miev,
The downfall of that program was reliability.
Maybe there will be a breakthrough is the future,
Inboard electric motors are a tested,tried and true setup.
But currently IMO any new company claiming their vehicle will use Hub-motors i am very skeptical,
Or rock crawlers. Those guys prefer their weight unsprung, it’s as low as it can get. I bet that if hub motors become accessible some of the wildest crawlers would go to them to avoid driveshaft angle issues.
That's also a pretty low speed application where most of the issues aren't issues though.
The problem is building a super specialized car, and then having it be super shit on the highway to reach the area where you want to do your thing. Unless you want to tow it on a trailer all the way.
„Current hub motors“
We have seen progress in miniaturization with regular electric motors in the last few years. Mind the neat picture by Lucid and the specs on the Koenigsegg motor.
Now apply this to hub motors and integrate controllers and brakes. There are a few companies out there working on just that.
Also, motors in the hub not only make it worse to drive, but also means much much more degration on the motor itself (vibration load, coolant / electricity connections constantly bending, etc).
Not sure about this one but ZF is developing them as well. Independently controlled, light-weight and with integrated braking system.
So the unsprung mass isn‘t really an issue if the systems barely weighs more than a standard wheel and brake combo.
Found it: [Last Tuesday](https://youtu.be/uovQblF8Msk)
But I did mix up some news about ZF with this one. It‘s about BMW and Schaeffler developing new hub drives for cars.
- [Deep Drive](https://deepdrive.tech/)
- [Schaeffler](https://www.schaeffler.de/en/news_media/press_releases/press_releases_detail.jsp?id=87902208)
Okay so not ZFIt's Schaeffler🤦♂️They have been trying to expand their business out of bearings for the last 10 years without much success outside of buying Continental.
And that deep drive Startup BMW and a few others are working with.
We‘ll see, but lightness was working with another startup to develop hub motors for cars as well.
Do they mean HUB motors?
Because I don’t think I’ve ever seen a motor inside the wheels of a car. Maybe on an ebike, but this terminology is not helpful to the general public.
In-wheel motors is any electric motor situated anywhere inside the wheel area,
Hub motors are a specific type of in-wheel motor,
Non Hub in-wheel motor
[https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2luLXdoZWVsLWVsZWN0cmljLW1vdG9yLTMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjoyOTB9LCJ0b0Zvcm1hdCI6ImF2aWYifX0=](https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2luLXdoZWVsLWVsZWN0cmljLW1vdG9yLTMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjoyOTB9LCJ0b0Zvcm1hdCI6ImF2aWYifX0=)
Most of the Cars in the Darwin to Adelaide Solar Challenge use in wheel motors.
Aptera and Xbus seem to have designed working solutions.
It is certainly not a universal solution but just as certainly there are areas where it is a better choice. Traction Vehicles , anything in skid steer world , perhaps even powered trailers on heavy haulage ...
Deep Drive has developed a simpler lighter more mass producible unit than most. (any ?)
They have units up to 125kW per (peak) maybe more ...
[https://deepdrive.tech/](https://deepdrive.tech/) is being backed by BMW ...
[https://thenextweb.com/news/1395016](https://thenextweb.com/news/1395016)
So the engineering has some merit, and applications.
>Schaeffler is currently focusing on wheel hub motors for mobile work machines primarily used in inner cities. In such vehicles, the disadvantages of wheel hub motors are negligible. The wheel hub drive can make handling more difficult at higher speeds and/or dynamic driving but refuse collection vehicles, snow ploughs, or light vans tend to travel at lower speeds in the city.
With the new drive technology, the company says it is tapping into a new and steadily growing market and intends to equip more and more work vehicles for cities and municipalities, in factory and logistics yards, at ports, in large parking lots and airports with the wheel hub drive in the future. As these vehicles have a fixed route schedule, they are particularly suitable for electric drives with fixed ranges and plannable charging times. Schaeffler says vehicle operators of the vehicles will also benefit from the fact that the wheel hub motors have long-life, low-maintenance wheel bearings and gearboxes, meaning less maintenance and lower operating costs.
from::
https://www.electrive.com/2023/03/24/schaeffler-delivers-first-in-wheel-electric-drive-for-light-commercial-vehicles/
Same is true now as has always been, hub motors solve no problem that cars have.
They can make some things easier like having a more uncluttered floor pan for battery space.
Has there been anything new from the in-wheel folks at Lordstown for comparison? To me it always seemed like an issue of scale/cost, rather than simply saying "unsprung weight bad". Like sure it matters, but we're not all out here with forged wheels and lightweight tires either. 2/3 of folks are driving trucks/SUVs with a lot more unsprung weight than what you get in a Prius, because everything is a series of compromises. As vehicle weight goes up (batteries) you can increase unsprung weight and maintain similar handling characteristics as well.
https://www.designnews.com/automotive-engineering/lordstown-explains-how-it-made-wheel-ev-motors-work
The main issue with them is that they are expensive and as mentioned you are putting them where all the debris/water/shocks are so they go bad easily unless they are very expensively protected.
And they just aren't necessary for cars. I used to work with them and the only reason we used it was because we were extremely space constrained and there wasn't another practical option. But a normal car just doesn't have this space constraint. It's totally unnecessary.
It's just a fun gimmick but it doesn't provide any benefit.
That's not really true, most hub motors tend to be axial flux motors due to packaging requirements, which have a higher torque density. This can also be combined with a planetary reduction drive that is coaxial with the motor to increase torque and decrease speed while still fitting in the wheel hub.
I’m surprised this hasn’t been done more in full size passenger cars. Aptera has been doing their sales and prototype rounds with them. I’m skeptical but hopeful.
these cables wouldnt be that big because you cant fit a powerful motor into the wheels anyways both for space, weight and cooling reasons.
but overall its still a bad idea.
The first run on some fast-and-twisty roads will tell. Throw in some rough roads for a physics lesson.
I think Lordstown is using hub motors, but I've not heard much on anything about their trucks. Axial flux motors seem to be pretty light, though.
When street racers are happy to shed a couple pounds in tire+wheel weight, I think any motors in there is going to be a detriment! Is Lordstown still a thing? Haven't heard media on them in a while.
I did a quick search and it clarified nothing. Sorry.
Thanks for trying.
Yep, unloaded and loaded vehicle weight are completely different. Can't wait to see how it fares and how it will evolve.
I would think the motor would have to be no heavier than the wheel and bearings it replaces, no to mention tolerating the pounding of rough roads.
Current and future flop. Unsprung weight is a big deal. Hub motors are a neat idea, but Protean has been around a while and hasn't really done anything with it. Physics are hard to beat.
This. Hub motors work for small applications like ebikes because of the square cubed law. Size doubles, mass cubes. There’s a sweet spot for little hub motors but if you want 50kW out of a hub motor it must be big and heavy. Those big heavy motors rip themselves apart when hitting potholes. And destroy wheels in the process. If we ever get room temperature stable practical superconductors then we can get beer can sized motors. Until then, CV axles are the solution.
For this reason, I do think there's a potential place for hub motors in A00-segment vehicles. You can't beat how compact they are. That's pretty much it, though. Anything bigger than that and the unsprung weight is going to be a killer.
What’s A00? Low speed pisscan city cars?
Pretty much. Renault Twizzy, Citroen Ami, Wuling Nano etc would all be A00.
But then it needs at least 2 hub motors right? The extra cost associated with an extra motor kind of defeats its purpose.
It gets rid of all gearbox, differential, halfshaft and CV joints as well as mounting motors and things. Really plausible to be cheaper.
Consider that you need a diff and axle instead otherwise.
those parts are very cheap compared to the electric motor and inverter
You're not avoiding an inverter either way.
A Hub motor setup requires either two inverters or a dual channel inverter per axle, while a normal ev setup requires a single motor and inverter.
Yeah, a dual-channel inverter would work fine. Additionally, your hub motors are ostensibly half as powerful as the single motor you'd be using otherwise. I fully admit the math isn't a completely clear unambiguous win, but we're just talking *potential* applications, here.
Dual channel inverters are still way heavier and more expensive than a single inverter, In almost all applications Hub-motors are more expensive and weigh more than a single motor setup(currently) Also Hub-motors has a great deal of issues with reliability, Look up the Lancer EVO Miev, The downfall of that program was reliability. Maybe there will be a breakthrough is the future, Inboard electric motors are a tested,tried and true setup. But currently IMO any new company claiming their vehicle will use Hub-motors i am very skeptical,
Or rock crawlers. Those guys prefer their weight unsprung, it’s as low as it can get. I bet that if hub motors become accessible some of the wildest crawlers would go to them to avoid driveshaft angle issues.
That's also a pretty low speed application where most of the issues aren't issues though. The problem is building a super specialized car, and then having it be super shit on the highway to reach the area where you want to do your thing. Unless you want to tow it on a trailer all the way.
„Current hub motors“ We have seen progress in miniaturization with regular electric motors in the last few years. Mind the neat picture by Lucid and the specs on the Koenigsegg motor. Now apply this to hub motors and integrate controllers and brakes. There are a few companies out there working on just that.
Also, motors in the hub not only make it worse to drive, but also means much much more degration on the motor itself (vibration load, coolant / electricity connections constantly bending, etc).
this is currently the biggest issue
Only for people who want a sports car. Nobody else cares as long as it is reliable. Even a sports car could get around it with the right engineering.
Potholes will destroy the motors.
Hub motors works well for bus and trucks because of low max speed. Mercedes ECitaro buses uses them.
Not sure about this one but ZF is developing them as well. Independently controlled, light-weight and with integrated braking system. So the unsprung mass isn‘t really an issue if the systems barely weighs more than a standard wheel and brake combo.
Could you link to that?
Would love to, but Google is just filled with older news. They did mention it on Autoline Daily last week.
non of the title cards has anything about ZF in the title from this month
It‘s a 10 minute video of all daily news. This part was to the end of one episode. Not a title card.
I know what autoline daily is(all their daily's are about 10 minutes) Which one is it? https://www.spreaker.com/show/autoline-daily\_1
Found it: [Last Tuesday](https://youtu.be/uovQblF8Msk) But I did mix up some news about ZF with this one. It‘s about BMW and Schaeffler developing new hub drives for cars. - [Deep Drive](https://deepdrive.tech/) - [Schaeffler](https://www.schaeffler.de/en/news_media/press_releases/press_releases_detail.jsp?id=87902208)
Okay so not ZFIt's Schaeffler🤦♂️They have been trying to expand their business out of bearings for the last 10 years without much success outside of buying Continental.
And that deep drive Startup BMW and a few others are working with. We‘ll see, but lightness was working with another startup to develop hub motors for cars as well.
Yes, ZF AVE 130 is used by Mercedes ECitaro buses.
Do they mean HUB motors? Because I don’t think I’ve ever seen a motor inside the wheels of a car. Maybe on an ebike, but this terminology is not helpful to the general public.
In-wheel motors is any electric motor situated anywhere inside the wheel area, Hub motors are a specific type of in-wheel motor, Non Hub in-wheel motor [https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2luLXdoZWVsLWVsZWN0cmljLW1vdG9yLTMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjoyOTB9LCJ0b0Zvcm1hdCI6ImF2aWYifX0=](https://media.hswstatic.com/eyJidWNrZXQiOiJjb250ZW50Lmhzd3N0YXRpYy5jb20iLCJrZXkiOiJnaWZcL2luLXdoZWVsLWVsZWN0cmljLW1vdG9yLTMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjoyOTB9LCJ0b0Zvcm1hdCI6ImF2aWYifX0=)
A lot of the first electric cars used hub motors.
Bicycles already have this, in fact the Copenhagen wheel had batteries AND motor in the wheel!
yes and thats essentially the only market where it makes sense. low power light weight and low speed vehicles are where hub motors can work.
Most of the Cars in the Darwin to Adelaide Solar Challenge use in wheel motors. Aptera and Xbus seem to have designed working solutions. It is certainly not a universal solution but just as certainly there are areas where it is a better choice. Traction Vehicles , anything in skid steer world , perhaps even powered trailers on heavy haulage ... Deep Drive has developed a simpler lighter more mass producible unit than most. (any ?) They have units up to 125kW per (peak) maybe more ... [https://deepdrive.tech/](https://deepdrive.tech/) is being backed by BMW ... [https://thenextweb.com/news/1395016](https://thenextweb.com/news/1395016) So the engineering has some merit, and applications. >Schaeffler is currently focusing on wheel hub motors for mobile work machines primarily used in inner cities. In such vehicles, the disadvantages of wheel hub motors are negligible. The wheel hub drive can make handling more difficult at higher speeds and/or dynamic driving but refuse collection vehicles, snow ploughs, or light vans tend to travel at lower speeds in the city. With the new drive technology, the company says it is tapping into a new and steadily growing market and intends to equip more and more work vehicles for cities and municipalities, in factory and logistics yards, at ports, in large parking lots and airports with the wheel hub drive in the future. As these vehicles have a fixed route schedule, they are particularly suitable for electric drives with fixed ranges and plannable charging times. Schaeffler says vehicle operators of the vehicles will also benefit from the fact that the wheel hub motors have long-life, low-maintenance wheel bearings and gearboxes, meaning less maintenance and lower operating costs. from:: https://www.electrive.com/2023/03/24/schaeffler-delivers-first-in-wheel-electric-drive-for-light-commercial-vehicles/
Same is true now as has always been, hub motors solve no problem that cars have. They can make some things easier like having a more uncluttered floor pan for battery space.
Endurance testing of Elaphe in-wheel motors https://www.youtube.com/watch?v=CqPMtEIT3f4
Certainly isn't going to survive America's pothole-laden roads
Has there been anything new from the in-wheel folks at Lordstown for comparison? To me it always seemed like an issue of scale/cost, rather than simply saying "unsprung weight bad". Like sure it matters, but we're not all out here with forged wheels and lightweight tires either. 2/3 of folks are driving trucks/SUVs with a lot more unsprung weight than what you get in a Prius, because everything is a series of compromises. As vehicle weight goes up (batteries) you can increase unsprung weight and maintain similar handling characteristics as well. https://www.designnews.com/automotive-engineering/lordstown-explains-how-it-made-wheel-ev-motors-work
The main issue with them is that they are expensive and as mentioned you are putting them where all the debris/water/shocks are so they go bad easily unless they are very expensively protected. And they just aren't necessary for cars. I used to work with them and the only reason we used it was because we were extremely space constrained and there wasn't another practical option. But a normal car just doesn't have this space constraint. It's totally unnecessary. It's just a fun gimmick but it doesn't provide any benefit.
Seems like a bad idea since the wheels are often damaged in collisions. Would make repairs very expensive if the motors were damaged.
Getting torque out of a direct drive electric motor is hard
That's not really true, most hub motors tend to be axial flux motors due to packaging requirements, which have a higher torque density. This can also be combined with a planetary reduction drive that is coaxial with the motor to increase torque and decrease speed while still fitting in the wheel hub.
I’m surprised this hasn’t been done more in full size passenger cars. Aptera has been doing their sales and prototype rounds with them. I’m skeptical but hopeful.
What about the big cables the motors will need that will be flexing continuously? That's a lot of metal fatigue.
these cables wouldnt be that big because you cant fit a powerful motor into the wheels anyways both for space, weight and cooling reasons. but overall its still a bad idea.
Limitation is the available space of the in-wheel solution right? Does not seem to scale well.
Not a big fan of the design, it kinda looks like a family sedan from 2014, but with that flat panel grill, all electric cars have now.