rim engine

[vax]

Just an idea - further development of car hub motors would be rim motors, that's magnets casted into car's aluminum rim and in the center would be hollow ring consisting of copper windings cast into epoxy. The whole thing shouldn't care much about water or other substances. The windings can be easily water cooled.
This way the torque can be increased (think about effective stator radius) and the motor can be much simpler.

 

[Link]

Given that I'm pretty sure I wasn't the only one to think of this after discovering hub motors and the fact that someone even makes them, I wouldn't be surprised if they ended up being the next "step" for hubs. Would up the stealth factor to the point to where even other ebikers would have trouble picking them out. :wink:

http://endless-sphere.com/forums/viewtopic.php?f=10&t=3440&p=50276

 

[TylerDurden]

There was some prior discussion of picking up metallic debris.

 

[Drunkskunk]

rims distort under normal driving. they take the shock load from the tires, and the weight load from cornering and breaking. thats why they don't cast in the break rotors or drums to wheels now. its very rartly truly round for long, and a motor needs a very tiny air gap, so the rotor needs to be very round.

Plus, any stray lug nut or paper clip fliped up by the tires against the rim would be trouble.