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Canadian Man Invented a Wheel That Can Make Cars Move Sideways (nationalpost.com)
An anonymous reader writes: Canadian man William Liddiard invented a wheel that allows vehicles to move sideways. "True all-way drive for anything with wheels," Liddiard says in an online writeup for his successful prototype of "omni-directional" wheels. They consist of a specialized roller-equipped rim that can move horizontally and a tire that is rounded like a donut. "This is a world first bolt-on application for anything with wheels," wrote Liddiard. "Now you can drive in all directions, and turn on the spot, when needed." His demo video titled "you've never seen a car do this...," has received more than 1.1 million views since it was uploaded on May 10th. The wheels are a "proof of concept" prototype right now, but Liddiard says the design would allow them to be made as durable and safe as standard automotive wheels. Omni-directional wheels are nothing new, though they are typically only used in wheelchairs, robotics and other small-scale applications. Honda Motor Co. debuted an omni-directional wheel at the 2009 Tokyo Motor Show, but it wasn't for a full-sized car -- it was for a Segway-style mobility device. "My wheel can hold ten times more than the other [wheels], while maintaining speed," Liddiard told Postmedia in an interview earlier this year. He's currently trying to sell his invention to a major tire or automotive company.
Unfortunately, if he thinks ' the design would allow them to be made as durable and safe as standard automotive wheels' them he has a nasty surprise coming.
Of course technically he is probably partially correct - the rims would post no problem.
However the tyres themselves? Not a chance, sorry.
Standard modern tyres combine a lot of technology to make them work as well as they do in griping, and most of that technology basically results in them not having a round cross section. The main width of the tread is close to flat, the sidewalls and base contain strong reinforcing bands, the bead carries large loads and the tread depth varies greatly from the center to the edges - all of this contributes to their effectiveness.
His 'invention' required the tyre to return to being a true 'doughnut' torus shape, which is a TERRIBLE shape for a tyre if you want any traction, as the contact patch is tiny. His invention also requires the torus to rotate on itself, placing huge stress on the inner and outer surfaces as it rotates sideways, which will result is high wear and low lifespan.
Basically, sorry but it is a non-starter for anything outside short lifespan, low load and low speed applications, and problem that is already well solved with sidewinder/mechanum 'tyres' which are a group of cones, and suffer for less issues than his system would (although speed is still a major issue, and traction a medium one)
Still, the media will love it, and people will 'wow' at the example video. A set of car wheel skates/dollies let you push a car around like this at low speed quite easily already, and have been around for a long LONG time - and are about as practical.
A forklift you say?
It's completely flat, it will have no "grip" to the ground.
This is a common misconception: flat tyres actually grip the ground better than tyres with a tread because they have a larger surface area in contact with the ground which generates more friction. This is why Formula 1 cars have flat tyres when racing in dry conditions. The tread is there because in wet conditions you need channels to get rid of the water between the tyre and the road when travelling at speed otherwise you hydroplane. So the tread is not there to increase grip but to get rid of water and as these tyres are now they will not grip well at speed in wet conditions but they will actually grip better than a treaded tyre in dry conditions.