3 ms·

The next logical step would be integrate the motor directly into the wheel. With 4 wheel drive motors it wouldn't require huge motors, they could each be small

The next logical step would be integrate the motor directly into the wheel. With 4 wheel drive motors it wouldn't require huge motors, they could each be small enough to be packed right up against the inside of the wheel. I'm actually surprised they would even need the gearbox. Why not just put four Outrunner[1] motors, one on each wheel, and let the wiring be the only thing that has to flex when the wheel is steered. 1. https://en.wikipedia.org/wiki/Outrunner https://en.wikipedia.org/wiki/Outrunner

idiotsecant 3y ago
Hub motors have existed for a long time. The issues you'll have to overcome are the same.
geoduck14 3y ago
I agree, hub motors [0] have been around for over a decade and are used to power EVs in races. I don't really know why these aren't being considered here. [0]https://www.explainthatstuff.com/hubmotors.html https://www.explainthatstuff.com/hubmotors.html
emilecantin 3y ago
It's been invented in Québec in the 90s[1] by our national utility company, they had demo cars and everything. Then it was all swept under the rug after some secret deals with car manufacturers... 1. https://fr.wikipedia.org/wiki/Moteur-roue_d'Hydro-Qu%C3%A9bec https://fr.wikipedia.org/wiki/Moteur-roue_d'Hydro-Qu%C3%A9be... (in French only, sorry!)
pxndxx 3y ago
Hub motors make wheels quite heavy, which means that there's more unsprung mass [1] in the vehicle, making it less responsive under acceleration/braking and more noisy and sensitive to vibrations. They're common in electric scooters, bikes and bicycles though. [1] https://en.wikipedia.org/wiki/Unsprung_mass https://en.wikipedia.org/wiki/Unsprung_mass
- reactordev 3y ago
  newer designs are silent, weigh about 2lbs or a little under a kilo, can produce upwards of 100nm torque at 1000w.
  - pornel 3y ago
    1kW isn't going to suffice. Car motors are >100kW.
    - reactordev 3y ago
      Well, that’s overkill for Hyundais, 20-50kW max is all you need per wheel. You can produce >100kW with some high end racing hub motors [1]. You can also scale it up to generate more torque. Gear it down, etc. [1] https://www.koenigsegg.com/quark-emotor https://www.koenigsegg.com/quark-emotor
reactordev 3y ago
I thought the same thing and was disappointed to see a planetary gear setup to turn an outer ring gear. Shame, we have come so far in EV motor design and yet Hyundai seems stuck on drivetrain power design.
- metabagel 3y ago
  My experience with a planetary gear in a bicycle is that it produces additional noise. I wonder if this would be noticeable for an automobile.
  - reactordev 3y ago
    I'm sure it would. Any mechanical gears will produce noise at higher velocities so curious what this sounds like myself. Electric hub motors produce a wine from the EMF that is audible but that's a different sound (the hum of a tesla going by) or a Surron that uses a radial flux motor with chain link gears (this is my favorite hobby design, chain gears are super useful).
    - tempmac 3y ago
      > Electric hub motors produce a wine from the EMF the sound is not coming from EMF, but rather from speakers due to safety regulations for pedestrians
pbronez 3y ago
Aptera is using in-wheel motors for their upcoming autocycle https://www.electrive.com/2022/06/23/aptera-orders-in-wheel-motors-from-elaphe/ https://www.electrive.com/2022/06/23/aptera-orders-in-wheel-...

idiotsecant 3y ago

Hub motors have existed for a long time. The issues you'll have to overcome are the same.

geoduck14 3y ago

I agree, hub motors [0] have been around for over a decade and are used to power EVs in races. I don't really know why these aren't being considered here. [0]https://www.explainthatstuff.com/hubmotors.html https://www.explainthatstuff.com/hubmotors.html

emilecantin 3y ago

It's been invented in Québec in the 90s[1] by our national utility company, they had demo cars and everything. Then it was all swept under the rug after some secret deals with car manufacturers... 1. https://fr.wikipedia.org/wiki/Moteur-roue_d'Hydro-Qu%C3%A9bec https://fr.wikipedia.org/wiki/Moteur-roue_d'Hydro-Qu%C3%A9be... (in French only, sorry!)

pxndxx 3y ago

Hub motors make wheels quite heavy, which means that there's more unsprung mass [1] in the vehicle, making it less responsive under acceleration/braking and more noisy and sensitive to vibrations. They're common in electric scooters, bikes and bicycles though. [1] https://en.wikipedia.org/wiki/Unsprung_mass https://en.wikipedia.org/wiki/Unsprung_mass

reactordev 3y ago
newer designs are silent, weigh about 2lbs or a little under a kilo, can produce upwards of 100nm torque at 1000w.
- pornel 3y ago
  1kW isn't going to suffice. Car motors are >100kW.
  - reactordev 3y ago
    Well, that’s overkill for Hyundais, 20-50kW max is all you need per wheel. You can produce >100kW with some high end racing hub motors [1]. You can also scale it up to generate more torque. Gear it down, etc. [1] https://www.koenigsegg.com/quark-emotor https://www.koenigsegg.com/quark-emotor

reactordev 3y ago

I thought the same thing and was disappointed to see a planetary gear setup to turn an outer ring gear. Shame, we have come so far in EV motor design and yet Hyundai seems stuck on drivetrain power design.

metabagel 3y ago
My experience with a planetary gear in a bicycle is that it produces additional noise. I wonder if this would be noticeable for an automobile.
- reactordev 3y ago
  I'm sure it would. Any mechanical gears will produce noise at higher velocities so curious what this sounds like myself. Electric hub motors produce a wine from the EMF that is audible but that's a different sound (the hum of a tesla going by) or a Surron that uses a radial flux motor with chain link gears (this is my favorite hobby design, chain gears are super useful).
  - tempmac 3y ago
    > Electric hub motors produce a wine from the EMF the sound is not coming from EMF, but rather from speakers due to safety regulations for pedestrians

pbronez 3y ago

Aptera is using in-wheel motors for their upcoming autocycle https://www.electrive.com/2022/06/23/aptera-orders-in-wheel-motors-from-elaphe/ https://www.electrive.com/2022/06/23/aptera-orders-in-wheel-...