4 ms·

Hey at last, maybe in my lifetime I'll see the motor per wheel AWD design I've been fathoming for the past ten years.

chriscappuccio 8y ago
this design is much cooler
cgio 8y ago
Yes, I've been imagining this too since 25 years ago now, also thinking how it would not need turning wheels, just power differential like paddling a boat. Not sure if this part can be done though or if it would break under the pressure... I should have studied engineering to find out.
- baybal2 8y ago
  Chinese lsevs do exactly that. One banal BLDC for each wheel, but more often just two
- zepolen 8y ago
  No steering wheel...that is an interesting idea, I don't think pressure would be a problem, but sensitivity might be.
- EmbarrassedFuel 8y ago
  This is how tanks steer! And also (to some extent) why using them on roads ruins the roads. If you tried in a traditionally wheeled car then all of the drive shafts would snap though!
  - ddalex 8y ago
    I used to think that the treads actually ruin the road because it changes to contact surface on which you apply the power differential from a line (on a tire) to a rectangle(the tread), i.e. it tries to rotate a flat surface which can't be rotated, so somethings got to give. Arguably a tire wouldn't have the same problem.
- MertsA 8y ago
  No turning wheels means no parallel parking. Zero turning radius would be cool, but even with complete differential steering that would scrub the tires a bit much. I don't think you could practically remove steering tires entirely. I think you're still stuck with a rack and pinion, ball joints, tie rods, strut bearings, etc so even with AWD with independent electric motors on all wheels differential steering isn't really that useful. On a performance car, it'll help with handling around turns. I don't see that becoming commonplace on average cars because of the added cost.
chrisbennet 8y ago
Fun fact: The Lohner-Porsche had a gas motor and 4 electric motors; one in each in wheel in 1900.
- zepolen 8y ago
  Cool but not the system I'm thinking of: A complete real time tweaking of per wheel outputs based on live slip/velocity/momentum for perfect AWD.
  - tmrmn 8y ago
    AFAIK the Mercedes SLS Electric Drive did that in 2013 https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=9904727 https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml...
  - EmbarrassedFuel 8y ago
    In addition to the sls this idea is deployed to some extent in IC cars as well: electronic limited slip differentials can send continuously varying torque to each wheel, see the Porsche 918 spyder (combo electric and IC) or the Nissan GT-R which has a famously odd driving characteristic as a result of the computer controlled torque vectoring.
  - kingkongjaffa 8y ago
    Formula Student Cars have had this for years, check out TU Delft Formula Student Electric vehicle. Full AWD Torque vectoring.
rodgerd 8y ago
Your wish is granted: https://www.youtube.com/watch?time_continue=718&v=qeXZs_XAmME https://www.youtube.com/watch?time_continue=718&v=qeXZs_XAmM...
- zepolen 8y ago
  Woah! Looks like it is. https://doubleapex.co.za/schaeffler-audi-4e-performance-concept/ https://doubleapex.co.za/schaeffler-audi-4e-performance-conc...
aasasd 8y ago
Afaik big trucks had that for quite some time now.
oldboyFX 8y ago
A Croatian company built two fully electric hypercars with 1 motor per wheel and a torque vectoring system: Rimac Concept One (the old model): - Acceleration: https://www.youtube.com/watch?v=eT7KKxoAvvk https://www.youtube.com/watch?v=eT7KKxoAvvk - Presentation at Stanford: https://www.youtube.com/watch?v=1FsrgJ66wUw https://www.youtube.com/watch?v=1FsrgJ66wUw Rimac Concept Two (the new model, they plan to build ~150 of them): - Geneva motors show: https://www.youtube.com/watch?v=XvjvYzzBh-k https://www.youtube.com/watch?v=XvjvYzzBh-k - Company website: http://www.rimac-automobili.com/en/ http://www.rimac-automobili.com/en/
- davidrm 8y ago
  We, Rimac, are also supplying Koenigsegg with the battery packs for Regera, feel free to AMA, hopefully I'll be able and allowed to answer :)
wil421 8y ago
Why not let the differential(s) distribute the power? I’m sure one or two larger motors is better than 4 small ones. I would like to see a serious off-road EV.

this design is much cooler

cgio 8y ago

Yes, I've been imagining this too since 25 years ago now, also thinking how it would not need turning wheels, just power differential like paddling a boat. Not sure if this part can be done though or if it would break under the pressure... I should have studied engineering to find out.

baybal2 8y ago
Chinese lsevs do exactly that. One banal BLDC for each wheel, but more often just two
zepolen 8y ago
No steering wheel...that is an interesting idea, I don't think pressure would be a problem, but sensitivity might be.
EmbarrassedFuel 8y ago
This is how tanks steer! And also (to some extent) why using them on roads ruins the roads. If you tried in a traditionally wheeled car then all of the drive shafts would snap though!
- ddalex 8y ago
  I used to think that the treads actually ruin the road because it changes to contact surface on which you apply the power differential from a line (on a tire) to a rectangle(the tread), i.e. it tries to rotate a flat surface which can't be rotated, so somethings got to give. Arguably a tire wouldn't have the same problem.
MertsA 8y ago
No turning wheels means no parallel parking. Zero turning radius would be cool, but even with complete differential steering that would scrub the tires a bit much. I don't think you could practically remove steering tires entirely. I think you're still stuck with a rack and pinion, ball joints, tie rods, strut bearings, etc so even with AWD with independent electric motors on all wheels differential steering isn't really that useful. On a performance car, it'll help with handling around turns. I don't see that becoming commonplace on average cars because of the added cost.

chrisbennet 8y ago

Fun fact: The Lohner-Porsche had a gas motor and 4 electric motors; one in each in wheel in 1900.

zepolen 8y ago
Cool but not the system I'm thinking of: A complete real time tweaking of per wheel outputs based on live slip/velocity/momentum for perfect AWD.
- tmrmn 8y ago
  AFAIK the Mercedes SLS Electric Drive did that in 2013 https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml?oid=9904727 https://media.daimler.com/marsMediaSite/en/instance/ko.xhtml...
- EmbarrassedFuel 8y ago
  In addition to the sls this idea is deployed to some extent in IC cars as well: electronic limited slip differentials can send continuously varying torque to each wheel, see the Porsche 918 spyder (combo electric and IC) or the Nissan GT-R which has a famously odd driving characteristic as a result of the computer controlled torque vectoring.
- kingkongjaffa 8y ago
  Formula Student Cars have had this for years, check out TU Delft Formula Student Electric vehicle. Full AWD Torque vectoring.

rodgerd 8y ago

Your wish is granted: https://www.youtube.com/watch?time_continue=718&v=qeXZs_XAmME https://www.youtube.com/watch?time_continue=718&v=qeXZs_XAmM...

zepolen 8y ago
Woah! Looks like it is. https://doubleapex.co.za/schaeffler-audi-4e-performance-concept/ https://doubleapex.co.za/schaeffler-audi-4e-performance-conc...

aasasd 8y ago

Afaik big trucks had that for quite some time now.

oldboyFX 8y ago

A Croatian company built two fully electric hypercars with 1 motor per wheel and a torque vectoring system: Rimac Concept One (the old model): - Acceleration: https://www.youtube.com/watch?v=eT7KKxoAvvk https://www.youtube.com/watch?v=eT7KKxoAvvk - Presentation at Stanford: https://www.youtube.com/watch?v=1FsrgJ66wUw https://www.youtube.com/watch?v=1FsrgJ66wUw Rimac Concept Two (the new model, they plan to build ~150 of them): - Geneva motors show: https://www.youtube.com/watch?v=XvjvYzzBh-k https://www.youtube.com/watch?v=XvjvYzzBh-k - Company website: http://www.rimac-automobili.com/en/ http://www.rimac-automobili.com/en/

davidrm 8y ago
We, Rimac, are also supplying Koenigsegg with the battery packs for Regera, feel free to AMA, hopefully I'll be able and allowed to answer :)

wil421 8y ago

Why not let the differential(s) distribute the power? I’m sure one or two larger motors is better than 4 small ones. I would like to see a serious off-road EV.