Reinventing the Wheel

[outsidethebox]

Hi,

 

Have you seen this shape? It is the intersection between a sphere and a cube.

 

It has many performance advantages and one disadvantage over the traditional circular wheel.

 

I wanted to hear thoughts about it before I elaborated further, thanks.

 

 

[John Cuthber]

"I wanted to hear thoughts about it before I elaborated further, thanks."

OK, given this "it has many performance advantages and one disadvantage..." I come to the conclusion that the inventor is unable to count or doesn't know what constitutes a disadvantage. This may be a problem.

 

Two obvious disadvantages are the difficulty of manufacture and the requirement for cross bracing or rigidity- you couldn't just hold it in place with spokes like an ordinary wheel.

Then you can add the fact that it takes more material

And the difficulty of fitting rim brakes and...

 

 

So, let us know- what are the advantages?

[Acme]

From what I have seen, it's for skateboards and called the Sharkwheel.

 

Sharkwheel

David M. Patrick discovered the shape while studying natural sciences, and has since been developing the Shark Wheel to be a more efficient wheel with defined performance advantages.

 

1. Finite dynamic analysis test and real world testing of wheel in Canada. Third party tested the Shark Wheel's performance under friction and tested its longevity. The Shark Wheel lasted 10% longer than any wheel they have ever tested. A traditional wheel has one defined center point and wears unevenly under friction. The Shark Wheel has a constantly changing center point, and is 540 degrees (as opposed to a traditional wheel at 360 degrees) and therefore lasts longer.

 

2. Stress testing at UCLA school of engineering. A traditional wheel has nearly all of the stress on the bearing. The Shark Wheel disperses stresses along its six undulations evenly. Less stress is placed on the center/bearings and therefore the bearings will last longer when using the Shark Wheel. ...

[outsidethebox]

"I wanted to hear thoughts about it before I elaborated further, thanks."

OK, given this "it has many performance advantages and one disadvantage..." I come to the conclusion that the inventor is unable to count or doesn't know what constitutes a disadvantage. This may be a problem.

 

Two obvious disadvantages are the difficulty of manufacture and the requirement for cross bracing or rigidity- you couldn't just hold it in place with spokes like an ordinary wheel.

Then you can add the fact that it takes more material

And the difficulty of fitting rim brakes and...

 

 

So, let us know- what are the advantages?

Hi, thanks for your reply.

 

Don't jump to conclusions!

 

The major disadvantage is that the shape does not like to lean/tilt. Once it tilts past 22.5 degrees you would experience a heavy 'wobble'.

 

The manufacturing disadvantage you mentioned.... yes, it is extremely difficult to mass produce the wheel. But, since we (yes, I am part of the company) figured out how to manufacture the wheel within the same tolerances/time lines/cost as any other wheel, manufacturing has become an advantage (because copying us would be incredibly difficult - it took us months to figure out how to conform to the time lines of a traditional assembly line)

 

Actually, you can hold the wheel in place with normal spokes. The wheel averages to a perfect circle in the center and a normal hub can be used. Also, disc brakes (correct, not rim brakes if you are talking about a bike) could be used.

 

Advantages:

 

The wheel acts like a thin profile wheel on hard terrain-the same speed of any wheel of comparable contact patch. But, the wheel acts like a wide wheel when it loses traction on soft terrain. It is essentially a wide wheel and a thin wheel in one shape. Also, in skateboarding we have less rolling resistance for high speeds, more slide control because of 3 sine wave shaped lips instead of one circular lip, and maybe our best feature is the ability to go over rough terrain. When skateboarding over pebbles, debris, etc you barely feel the bumps in the road. Most of it is either pushed aside by the sine wave or funneled through the sine wave grooves. You don't have to steamroll over every bump in the road.

From what I have seen, it's for skateboards and called the Sharkwheel.

 

Sharkwheel

Yes, it is currently only for skateboarding. But, it is a wheel and we plan to enter many industries (that do not tilt like a bike, motorcycle, etc)

[Ophiolite]

Have you done any FEA work on bearing loads with the wheel? If so, how does the loading differ from a conventional arrangement?

[outsidethebox]

Have you done any FEA work on bearing loads with the wheel? If so, how does the loading differ from a conventional arrangement?

 

 

The above guy posted this which is accurate:

 

1. Finite dynamic analysis test and real world testing of wheel in Canada. Third party tested the Shark Wheel's performance under friction and tested its longevity. The Shark Wheel lasted 10% longer than any wheel they have ever tested. A traditional wheel has one defined center point and wears unevenly under friction. The Shark Wheel has a constantly changing center point, and is 540 degrees (as opposed to a traditional wheel at 360 degrees) and therefore lasts longer.

 

2. Stress testing at UCLA school of engineering. A traditional wheel has nearly all of the stress on the bearing. The Shark Wheel disperses stresses along its six undulations evenly. Less stress is placed on the center/bearings and therefore the bearings will last longer when using the Shark Wheel.

[John Cuthber]

 

 

Actually, you can hold the wheel in place with normal spokes. The wheel averages to a perfect circle in the center and a normal hub can be used. Also, disc brakes (correct, not rim brakes if you are talking about a bike) could be used.

 

everything averages to a circle, so that doesn't tell us anything.

If you tried to make that rim shape with spokes they wouldn't be in simple tension since that would twist the wheel more or less out of shape.

If it takes more material (and it does) there's no surprise that it lasts longer.

[studiot]

This was posted here a year ago, resulting in some interesting comments.

 

http://physicsbuzz.physicscentral.com/2013/06/reinventing-wheel.html

 

The physicist in the link was totally skeptical.

 

However I have an open mind to further persuasion.

 

I note, for instance that any side thrust puts great bending stress on an axle and greatly increases wear. The wider the wheel the lower this effect and the skateboard wheels are certainly wide.

 

For bicycles to achive the cubical idea a bike wheel would have to be two foot to two foot six wide!

 

Now this latter has been done with the popular 'ballbarrow', whose main claim is the ease of turning corners with a loaded wheelbarrow.

Edited July 19, 2014 by studiot

[outsidethebox]

everything averages to a circle, so that doesn't tell us anything.

If you tried to make that rim shape with spokes they wouldn't be in simple tension since that would twist the wheel more or less out of shape.

If it takes more material (and it does) there's no surprise that it lasts longer.

 

Hi,

 

Not sure what you mean by 'everything averages to a circle'. I was saying the center of the wheel becomes a flat circular disc-it is no longer wavy in the center.

 

We make a mag-type wheel. That is what I meant regarding spokes. We already have it and it doesn't twist the wheel out of shape.

 

A circular wheel with the effective width of say 6'' (contact patch=6 inches) compared to the Shark Wheel with an effective width of 6'' (contact patch= about 2''). A circular wheel has more material. It's not close. The Shark Wheel can be very wide, while still putting a small footprint on the ground.