Do we need hubs?
 

With the right alloy wheel, why not machine the center and press in bearing races?

Crappy MS Paint picture of my idea: ('Wheels' to the left)
http://sphotos.xx.fbcdn.net/hphotos-...66208348_n.jpg

As I was thinking about making a floating axle hub for a project I'm developing, I got to thinking, "Why bother with a hub?"

Besides, the obvious benefit of speedier tire changes; why not do away with it? Why not make the wheel, hub, and rotor hat one piece? There's several pounds of sprung weight and rotational mass shed right there.

So you want to integrate your brakes into the wheels then?

That and the bearings are usually located in the centerline of the tires to minimize loading

Getting those disc calipers off would be a total PITA. Drum brakes however...

I would hate to have to replace my wheels every time my brake discs need machining, or try to figure out how to machine the integrated disc... unless we went back to the brake shoe directly acting on the outside of the tire http://www.mofga.org/Portals/2/mof&g...nneth-Copp.jpg

why not perfect electronic braking and eliminate the rotor entirely?

VW has the wheel bearings pressed in to the rear brake drum and it makes them a pain to deal with, a side effect is that the rear brake drums have to be replaced more often because the brake shoes wear out and score the drums beyond repair because the shoes were not inspected as often.
Other cars where the drums are held on by the wheel being held in place are easy to check the brakes when rotating tires or changing from summer to winter tires, so I could not imagine how annoying having the wheel bearings pressed in to the wheel would be.

Look ma! No hubs!

http://www.likecool.com/Car/Motorcyc...orcycle---.jpg

I'll see you, three hublesses,...http://sbarro.perso.neuf.fr/voitures...Aero_Paris.jpg

...make that four hublesses.
http://www.youtube.com/watch?v=YKx4DWsxm2g

...with: motor / generator = power / braking (regeneration!)

Concerning the rotors: The wheel would only serve as the rotor "hat." If you've never seen two-piece racing disks, the center "hat" is aluminum to save weight. Using studs pressed into the rotor, you could fasten it from the outside of the wheel and have features in the backing plate to hang it while changing the wheel.

Removing the wheel: I was planning on using 4130 tubing to make a hollow spindle anyways (floating hubs facilitate bolting on electric motors for future drivetrain development.) I could just make it so that it threads into the uprights and leave the bearings alone. If I use a wide enough diameter, it will fit over the shaft of a tire balancer (40mm?) and I could make the centering cones if necessary. The act of changing the actual tire is unaffected.

Disclaimer: I'm only saying it could be done. The vehicle in question will be built from scratch with an emphasis on pushing my design ability. It is definitely less convenient than conventional designs. It probably isn't worth doing but this vehicle is going to serve as my resume some day.

Would this mean that tire changes would affect the alignment of the brake discs? Or will there be a simple bolt or clip to hold them in when changing wheels?

well most hub designs are double bearing leading to a decent life span for the bearings(two bearings really close would probably lead to one failing pretty quickly; think weight over distance); the hub centric design is so anyone can center the wheel(lowest common denominator); and it probably cuts down on the number of studs needed to carry the cars weight fully loaded(that and you can technically drive a good distance with only missing one lug nut from each of the tires)

i think i'm looking at it wrong, but i think it looks like its from old 2wd vehicles, spindle, bearings, outer bearing races pressed into the rotor assembly, but they had wheel studs pressed through the rotor.

if you have the rotor attached to the wheel, how do you get the caliper off?

Because the braking effectiveness of electric brakes (regen) depends on the speed with which the rotor rotates. If it's not rotating at all, there's zero braking force - think parking brakes, holding on hills, etc.

Right, which is why i said perfect not use the current.;)

You can't "perfect" electromagnet braking to do that, unless you can somehow manage to change the fundmental laws of physics.

Why can't an electromagnet hold stationary? I'm not sure I get why it couldn't be done... Enough magnetism between objects makes them VERY difficult to move. Keep going with that principle, and it could be completely impossible for a human to move them.

Granted, this takes a charged coil, which requires electricity, thus energy expense... but there's no reason mechanical brakes couldn't be MUCH smaller anyway for the final "stop and hold" as necessary if electronic/magnetic braking were used.

you're right, we can't. no sense in trying. i guess ill go back to driving my lifted 4x4, no sense in trying to save fuel. It CAN'T be done.

It's a waste of power.

Asking why a magnet can't hold a car stationary against a slope or acceleration is like asking why an electric motor can't do the same. Of course it could, but only by expending power and pushing the car against the force. Far more effective to have a mechanical brake for the last few km/h or mph.

Electric braking is obviously a good thing, but im not sure it is good enough for panic braking situations. That is where i was proposing we "perfect" electronic braking, it would also provide an even better abs system.

For safety reasons, a car would still (obviously) have to have a mechanical brake anyway. "Emergency" brake, if you will.

No sense in getting silly about it. You can't build a perpetual motion machine either, but does that mean there's no alternative to a gas-sucking 400 cubic inch V8?

I just have a passionate hatred for the word "can't". Anything is possible, just the effort involved that needs changed.

Go slam a revolving door.