Michelin reveals tyred thinking
Tyre-maker's technology transforms your wheels
Tyre maker Michelin highlighted three so-called breakthrough technologies at the recent auto show in Detroit. The Michelin Airless and Michelin Tweel are tyres without air. PistonHeads reported on the Airless in November (link below). Te third is an Active Wheel -- which could mean cars don't need suspension components. There's no sign of any of these products reaching mass production, yet.
Based on two different technologies and manufactured using composite technologies and new materials, these non-pneumatic products could make punctures a thing of the past and eliminate the need to check tyre pressure. They also use fewer raw materials and are retreadable.
Michelin Tweel
Michelin said the Tweel "is the fusion of the tyre and the wheel with the potential to transform mobility. Available now for lower-speed, lower-weight carrying vehicles, Tweel is in the prototype stage for passenger car applications. Tweel delivers the benefits of pneumatic radial tyre performance while dramatically increasing lateral stiffness, which affects handling, cornering and responsiveness. Additionally, Tweel has suspension-like characteristics that can simplify and in some applications eliminate the need for a separate vehicle suspension."
Michelin Airless
Michelin Airless enables vehicles to run safely and comfortably because its elastic characteristics are controlled longitudinally, transversally and vertically. A car doesn’t have to stop even if one or more of the radial bands break or are damaged. The Michelin Airless is being tested on passenger cars and motorcycles, but could be fitted to other vehicles as well.
Michelin Active Wheel
The Michelin Active Wheel is an integrated module comprised of a conventional tyre, plus an active electric suspension, a disc brake and an electric motor to provide traction and much of the braking power. Its compact size offers automotive engineers considerable design flexibility, said Michelin.
Michelin said the Active Wheel was the result of a total rethinking of the process whereby movement is transmitted. As well as doing what any wheel does -- roll to drive the vehicle forward -- the active wheel also acts as a suspension unit. This means that cars can be made without gearboxes, transmissions, differentials and stabiliser bars. Michelin reckons the Active Wheel will help to make cars lighter and simplify the transmission of movement.
Whilst it would have some effect, unsprung weight is much less important on a car than it is a light vehicle, such as a mountain bike (where wheels can form a large part of the bike's weight)
Also, it looks cr@p basically.
Solid "airless tyres" were available from Halfords some 10 years ago in loads of different colours.
Tioga (or similar) used a wheel with a cable insted of spokes and they won the world championship with it see the link for the wheel.
www.singletrackworld.com/mod/submit/images/1260-5.jpg
busta said:
My main concern with the Tweel would be that if you put alot of power through it all the spokey bits would just crumple as the rim inside turned befroe the tyre (or whatever it is) did. the same happens to bicycles rims if the spokes are put in radially and not cross laced.
Bernie
I you take a closer look at the 'tweel's' bottom spokes, it looks like that is what has happened to them.
errek72 said:
Yes, well, no points to the marketing department for the Tweel name then.
But having the shocks et al in the wheel -although great for packaging- increases the unspring weight, so dynamically is not good, right?
Any engineers who can comment on this?
Think again. This could potentially REDUCE unsprung weight. The motor could replace the brake disk and caliper as we know it, and shouldn't weigh any more than your standard steel system does now. The 'suspension' unit itself is actually far smaller than conventional wishbones, struts et al so potentially lighter.
Likewise there would be much reduced frictional losses from rotating components such as gearbox, driveshaft etc.
This is very clever technology (Not groundbreaking 'cos it's been conceptually on drawingboards for decades, but to actually make it work is something worth congratulating).
Disclaimer: The above comparisons relate to standard mass-production materials not expensive, low volume composites.
errek72 said:
Yes, well, no points to the marketing department for the Tweel name then.
But having the shocks et al in the wheel -although great for packaging- increases the unspring weight, so dynamically is not good, right?
Any engineers who can comment on this?
have you felt the weight of a conventional disk/caliper/hub? given that the motor/alternator does most of the braking i guess the normal disk can be replaced with a very small (low thermal capacity) disk even an alloy one (like a small version of the elise mmc disks). there's a chance the unsprung weight could be comparable. even if the 'new' wheel does have heavier unsprung weight, packaging is more important these days hence FWD cars now being the norm.
more intriguing is how the geometry works, bump steer, body roll etc...
francisb said:
more intriguing is how the geometry works, bump steer, body roll etc...
Because of less manoeuvering room for the springs/shocks?
This than would probably work well with a sporty car, especially a light one, and less so on luxery sedans, right?
Apart from the brakes do not forget the springs and shocks add weight to the wheel too.
Could both springs and shocks be replaced by an electric actuator (I might be going into star trek mode now
), reducing the wheel weight? Just curious
Speed Matters | Motoring News | Top of Page | What's New | My Stuff