Wheel Hub Motor on future vehicles and its effects

[xLeadxSledx]

I have been researching future trends in vehicle design lately and there seems to be a clear trend that most major manufacturers believe wheel hub motors will be used almost exclusively.

I can see the benefit in doing this because you are able to use the large wheel diameters to reduce motor currents, among other things.

The one side-effect I can see is the additional weight of a wheel/hub motor design compared to a traditional wheel/rim design and the effect of this extra weight on the suspension. Specifically the increased un-sprung weight versus the reduce body weight of a future vehicle (reduce body weight that would be needed to make an electric vehicle really viable).

Electric motors have come a long way, but so far, you cannot escape the need for lots of copper for high power/current designs that would be needed for a vehicle drivetrain.

I am more or less interested in what you folks have to say on this topic. I work in the robotics field but have always been interested in vehicle design.

Thank you up-front for your opinions.

 

[thundair]

Just to add to the frey... The motors could turn in the
opposite direction (planetary).

I haven't thought of this until now but could you counter balance for added weight?

I know something is wrong with that statement but it works on our large tools.

Cheers

I don't know anything but the people that do.

 

[kenvlach]

thundair,
that's fine, for straightaways!

 

[plasgears]

LeTourneau did the wheel motor in large earth moving vehicles many years ago. What was in their favor was large diameter wheels, which worked effectively in electric motors. The principle seems to apply to small, light vehicles with relatively large wheel hubs.

 

[xLeadxSledx]

plasgear. YUP! Seems to me in order to make the idea work you would have to put larger (proportionally) wheels on a vehicle in order to incorporate wheel hub motors.

 

[GregLocock]

How big were the wheels on the Mitsubishi 4wd electric drive demonstartor? They may have been 18s from memory. There again they were 50 kW motors.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[glantman]

Our electric car with 50kW (cant remember torque numbers, but over 200Nm each for the whole rev range) electric motors has 17 inch wheels, but the bigger the better to allow more room for larger wire in the windings (more current = more torque) etc.

Smaller cars dont need the huge amounts of torque, so smaller motors (and therfore wheels) would work.

Ryan

 

[glantman]

Hi Rod,
Our car website is

http://www.nzeco.net

We are working with Hybrid Auto in Brisbane who are supplying us with the 2 in-wheel electric motors and allowing us to use many components they have developed and helping us with their outstanding expertise and knowledge of electric cars.

Regards,
Ryan

 

[Veneta]

Hi Ryan,

I would like to know more about these in-wheel electric motors from Hybrid Auto. Could you give me a clue how to find more information about that? The link

http://www.nzeco.net

does not say nothing about hybrid cars or in-wheel electric motors. I called Hybrid Auto but a man that I contacted said he do not know that they supply nz company with in-wheel electric motors.

Regards,
Dimitar

 

[glantman]

Hi Dimitar,

Forgot to mention the project is for the University of Waikato, not a company and our website expired, so we are working on another one.

Hybrid Auto works out of Brisbane.

Cheers,
Ryan