Composite Toothed-Belt-Pneumatic Tyre

[paultrafalgar]

It has been said that friction drives are no good in the wet. How about a composite pneumatic tyre- toothed-belt. Imagine glueing (bonding) a kevlar toothed-belt to the circumference of a tyre. You could have an RC motor with sprung-release engagement that would allow for "freewheeling" (disengagement of the motor) so that there would be no drag when not using the motor. When the motor was "dropped" onto the tyre the drive teeth would engage in the teeth of the belt. Discuss.

 

[TylerDurden]

Teeth on the centerline would wear fast, no?

One friction-drive issue that has not been discussed much is mud... I imagine it is bad and teeth would prolly only make it worse.

 

[paultrafalgar]

Probably need the toothed-belt glued onto the rim, or one each side with two motors (Cybien style). How do you get a toothed-belt to take a driving-cog when the slots are radially distorted? Or is the distortion from parallel too small to matter? I had a Dutch tyre with a quarter-inch raised section on its circumference - lasted forever! Can't buy them now - too good!
I digress...

 

[Drunkskunk]

wouldn't work. a toothed belt works because the distance between the teeth never changes, but a tire works by constantly expanding and deflecting in response to the load and the road. you might get it to line up on a bike stand at a given airpressure, but as soon as you sit on it, the alignment would be shot on the teeth.

 

[Link]

Minus the belt and you might be on to something...

 

[JEB]

Years ago 30+ I road a bike that a older bike guy made to go into town, he used 2 surplus motors that were used to feed amo to the guns in a WW2 aircraft, he pinched the sides of the front tire with rubber rollars on the 2 gear reduced motors, as long as it was not raining (some wet roadway was ok) it was a kick to ride. The car sized batterys on a little pull behind trailer, the power on was motors in series, both motors on full, just on off control.

 

[Reid Welch]

It's do-able, sure, but it's not going to be low-rolling resistance, is it?

I think not. Thin slicks are the lowest rolling resistance tire, right?
And a cogged tread for a friction drive would offer, what? No slip in the rain,
but lots of noise and lots of wasted power, what with all those rubber nubbins
flexing and un-flexing. Rubber eats power through its internal friction, right?

 

[fechter]

It might be not so bad.

A friction roller works reasonably well on a regular tire. If the tire was well made, I think it should be no worse in terms of rolling resistance.

The pitch of the teeth can be designed so that they match properly under the actual operating conditions.

I think it might work better if you had teeth on the sidewalls of the tires and used rollers on both sides. This would help keep road crap off the teeth and allow a more optimum tread pattern.

The wear on the tire teeth won't be bad since there would be so many teeth around the circumference. The wear would be spread out.

The roller pinching mechanism can be designed so that the 'pinching force' is a function of motor thrust, so that under light load conditions, the pinching force (and friction) is minimal.