e-Traction

scottscott
Posted:
in General Discussion edited January 2014
Always a favorite topic here, better transportation.





The idea of an electric bus is not new. I've read about electric busses that use a diesel to generate electricity which is then used to drive electric motors on the wheels. An over all gain in efficiency.





This company, e-Traction has a new electric motor/wheel. As many know a typical motor has a housing that stays still and an axle that rotates. This company flipped it around. The rotating part is now the "housing" which is the hub of the wheel and the stationary part is now the center. It's a direct drive of the wheel with no gears and fewer moving parts.



They say they get a 50% increase in efficiency.



I wonder how it will stand up to a harsh Chicago winter.



Read about it on /.



Dutch Invention Uses Electric Engines For Wheels

Comments

  • Reply 1 of 9
    scottscott Posts: 7,431member
    I'm sorry I have to bump my own thread. This is cool stuff.
  • Reply 2 of 9
    andersanders Posts: 6,523member
    What is dotslash?
  • Reply 3 of 9
    scottscott Posts: 7,431member
    Good question!
  • Reply 4 of 9
    outsideroutsider Posts: 6,008member
    I was going to post this too but forgot. This is indeed cool technology. As we all know, IC engines are most efficient when running at constant speeds (rpm), that's why highway driving is more efficient than city stop and go driving. Electric engines, however, lose very little efficiency in comparison when doing stop and go driving. Also this makes for more robust IC engines because they run at constant speeds to charge the batteries unlike the engine in your car that fluctuates between ~500-4000 rpm a lot. It even opens up a whole multitude of generating options; diesel 4 stroke, gasoline 4 stroke, gasoline turbines, natural gas turbines, even methane/ethane fuel cells in the future.



    Also this technology sort of works like the motor in your ceiling fan, there is no need for a friction based commutator; the magnets are in the external 'can' housing. This means a more advanced electronic speed controller (versus a simple electronic speed controller or mechanical speed controller), but more efficient operation.



    Mass transit is a good place for this technology to start out in. It would be interesting to see how they could apply this to motor cycles however.
  • Reply 5 of 9
    scottscott Posts: 7,431member
    The other thing about electric motors is that they are at highest torque at the lowest RPM. So they're much better at getting a stopped bus moving again.
  • Reply 6 of 9
    shetlineshetline Posts: 4,695member
    Quote:

    Originally posted by Outsider

    Also this technology sort of works like the motor in your ceiling fan



    Will my ceiling fan be more efficient if I hold the fan blades still and let the whole house spin around the fan?
  • Reply 7 of 9
    billybobskybillybobsky Posts: 1,914member
    Quote:

    Originally posted by Outsider

    Electric engines, however, lose very little efficiency in comparison when doing stop and go driving.



    In fact electric engines are theoretically more efficient in city driving if there is an electronic breaking system that recovers some of the energy.
  • Reply 8 of 9
    scottscott Posts: 7,431member
    Which it does have.
  • Reply 9 of 9
    outsideroutsider Posts: 6,008member
    Quote:

    Originally posted by billybobsky

    In fact electric engines are theoretically more efficient in city driving if there is an electronic breaking system that recovers some of the energy.



    You are correct! Remember a generator is basically an electric motor. If you take a normal electric motor and turn the armature by hand or other mechanical means , it will generate some electricity at the power leads.
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