Spherical wheels

[MIKEY_!]

I'd say rollers positioned around the sides but that's all i can think of.

[amaire13]

I've given a lot of thought towards a mechanical setup for moving a spherical wheel and have a few concepts I would appreciate some feedback on.

Ball bots are a perfect starting point when considering different methods for how to mechanically make a car running on spheres work, but you have far moreleniency then those who developed the ball bots as the majority of the design for the ball bot is to help independently balance it.

A major problem with almost every single mechanical design for translating a spherical wheel would be slippage. The only way around slippage would be to use a rotating drive shaft, roller, omni-wheel, etc device you're using to provide movement to the wheel, and this is extremely limiting. You would in this case only be able to have at most 2 "drivers," and they would have to be exactly opposite from each other in respect to position on the sphere.

Slippage is a problem but with a smart design it can be minimized to controllable amounts. By far the most efficient ball bot in terms of managing slippage would be the Rezero project from the team in Zurich. This design is unique from the other ball bots in that the contact patch between the omni-wheels and the sphere is at one single, small point rather than a roller which has a large, rectangular contact patch on the wheel.

Through the use of complex planar geometric formulas that I barely understand, they have created an algorithm that modifies the torque amongst each omni-wheel to propel the ball in any direction they please, smoothly and nicely.

Taking the design found here and implementing it into something as large as a sphere wheel to run a car is a stretch, and I also understand that slippage will be far larger a problem on the larger scale. I come here to this forum to see if anyone has any ideas to offer on solutions are designs that could further make this design more efficient towards countering slippage.

[gold333]

Well just thinking logically the Rezero method will make a spherically wheeled car have an even more complex suspension model than cars we currently have. For a 4 sphered(?) car with the minimum of 3 rollers per sphere you have already 12 axles. And then the 4 bearings per sphere holding the spheres in place, 16 bearings. Can you imagine all the components that would need to be greased?

And that's without having considered a suspension system for these spheres at all.

Instead of all those analog bearings and opposing rollers the Rezero project uses to rotate the spherical wheels, why not just use maglev?

That way not only will the ride be smoother but assuming you can control the rideheight down to millimetres you'd get an awesome active suspension as well. I'm pretty sure you could do it down to the micron, let alone millimetre.

Didn't they levitate a frog a while back? Levitating a sphere inside a negative spherical space should be a piece of cake.

Hell maybe you could even use a Hoberman type sphere that could transform into a wheel when required. If you have no axles, uprights or rims you can do anything.

You wouldn't have a mechanical suspension either, it's definitely the future of locomotion the way I see it. I'd say between 75-200 years.

No brakes, no engine, no suspension, no transmission, no gearbox, no powertrain, no axles, no differential, no fuel, no oil, no radiator, no nothing.

Just a chassis with 4 electromagnets and 4 spheres.

[amaire13]

Levitation is possible, but something that we won't see for a long time. I don't see modern technology as being advanced enough to actually levitate a car... although who knows! Maybe someone will do it.

Anyway, I'm only looking at mechanical solutions right now as they have the most potential. Cars have lots of moving parts anyway. In this case its like taking the motor and dividing it up into 4 and placing it in each corner. Yeah, its 12 axles which is probably difficult to maintain, but not THAT difficult.

And yeah, 4 sphere car. Was just thinking how this could work on a motorcycle as well.

[gold333]

Levitation is possible, but something that we won't see for a long time. I don't see modern technology as being advanced enough to actually levitate a car... although who knows! Maybe someone will do it.

Anyway, I'm only looking at mechanical solutions right now as they have the most potential. Cars have lots of moving parts anyway. In this case its like taking the motor and dividing it up into 4 and placing it in each corner. Yeah, its 12 axles which is probably difficult to maintain, but not THAT difficult.

And yeah, 4 sphere car. Was just thinking how this could work on a motorcycle as well.

1. Mechanically you need pretty much what Rezero has. But levitation should be very easy in my mind. You are not levitating the car, you are merely repulsing the wheels away from the chassis. The metal cored, rubber coated wheels push against the ground.

They can maglev a whole train at 360mph, why not a car?

2. For motorcycles it would (in my mind) be less desireable. 99% of the force preventing the bike from falling over is the rotational inertia of the wheels. The size of object required to create this angular momentum (given the overall weight and size of the bike) and the fact that the bike ideally has to fit between your legs means a wheel is more suitable than a sphere.

Unless you are going to lie on top of it or use some insanely complex gimballing or gyroscoping computer controlled balance. The simplest solution is just 2 big rotating wheels.

[amaire13]

You are not levitating the car, you are merely repulsing the wheels away from the chassis.

Unless you are dragging the car against the ground, the car is being levitated. Trains are far easier to levitate than cars because they run on a designated track, unlike cars which travel anywhere on a road.

99% of the force preventing the bike from falling over is the rotational inertia of the wheels.

The momentum of a sphere bike and wheel bike would be no different, and in this case would be virtually the same in terms of the bike standing up. It might actually be better to use spheres on a bike because you can change the position of the body of the bike against the spheres without turning, like on a wheel bike.

[gold333]

You are not levitating the car, you are merely repulsing the wheels away from the chassis.

Unless you are dragging the car against the ground, the car is being levitated. Trains are far easier to levitate than cars because they run on a designated track, unlike cars which travel anywhere on a road.

99% of the force preventing the bike from falling over is the rotational inertia of the wheels.

The momentum of a sphere bike and wheel bike would be no different, and in this case would be virtually the same in terms of the bike standing up. It might actually be better to use spheres on a bike because you can change the position of the body of the bike against the spheres without turning, like on a wheel bike.

Yes but in a sphered bike you wouldn't need to change the body position of the bike with respect to the spheres unless you were turning. And even then as just a matter of comfort for the rider because of the centripetal forces on the upper body. Or just use a carseat on the bike.

I still insist that maglev levitation for spheres is entirely possible. The road surface (track rails or highway) is completely irrelevant.

To levitate a 600 pound maglev train at 0 speed requires 270 watts. That's less that 0.5 horsepower. So around 1 kilowatt per metric ton for a sportscar (2,205 lbs). That's less than 2hp.

Put simply, try to force 2 equal magnet poles together using 2 small magnets. It is virtually impossible. In the car the chassis repels the spherical wheel, the wheel pushes against the ground like in a normal car. The chassis can then be said to levitate above the spheres.