Jake Holmes of Engineer Live investigates the latest developments in airless tyre technology.
The wheel was first invented around 3500 BCE, with its most recent major adaptation being in 1888 when John Boyd Dunlop invented the first practical tyre. Since then, tyres have undergone small design changes to make them more applicable to certain environments and applications, but the fundamental principles have remained the same.
This may now be changing, however. Michelin and Bridgestone are in the process of testing an airless tyre, first unveiled to the world back in 2019. Tests are currently ongoing, with the prospect of the tyres helping to advance self-driving capabilities. There are a few current examples of real-world application, but these are presently limited due to the wheels still being in the prototype phase.
Why Change?
One of the key benefits of airless tyres is that they reduce the chances of punctures to zero. This decreases costs associated with crashes or delays due to tyre blowouts, leading to more reliable and on-time deliveries and improved knock-on effects throughout the industry.
There is also an environmental benefit, as the reduction in tyres being scrapped means higher efficiency of tyre use and less raw materials being required to service the same number of vehicles.
Michelin’s airless tyre – Uptis – is built on the company’s four pillars of innovation, with those being: airless, connected, 3D-printed, and 100% sustainable. The development signifies a move towards innovation, with an eye on self-driving vehicle requirements and eco-responsibility, as the tyres are both renewable and bio-sourced.
According to Michelin, implementing tyres that do not puncture creates a safer environment for commercial vehicles and further enables the use of self-driving vehicles in commercial settings. This is because employees would no longer be required to have the training to change a tyre, but would also not need to take on this responsibility.
This could potentially bring down labour costs and reduce operating costs, while lessening the overall cost of ownership for drivers. DHL and La Poste small vans have already been fitted with the tyres despite the technology remaining at prototype stage. According to the Financial Times, logistics groups are ‘very happy’ with the tyres, but at present they are not ready for further industrial use.
Looking At The Tech
Bridgestone and Michelin have developed the tyre using new computer-enabled structures and materials. The tyre is currently able to support up to 1-tonne vehicles driving up to 60km per hour. According to the partners, this is an improvement over solid tyres’ ability 10 years ago.
The implementation of computer generation has allowed innovations in design, enabling improved performance at higher speeds and weights. It has become feasible that the airless tyres could soon replace pneumatic tyres due to these developments.
The tyre is made up of a rubber thread that surrounds and encases a spoke structure. The spokes are able to bounce and bend at high speeds and weights without hindering fuel consumption. This provides a smooth and safe ride without compromising fuel economy, an improvement on previous airless tyres.
The spokes are made of glass fibre reinforced with plastic, creating a flexible load-bearing structure. The inner wheel is constructed using aluminium, as standard on many modern wheels. The outer wheel is still constructed of rubber to provide durability to the tyre.
Future Impact
Japan is keen on implementing any technology that will aid driverless technology, with the tyres currently being trialled on shuttle buses and tourist vehicles. The country is hoping to introduce driver-less technology to rural communities due to the shortage of people in the labour market in the automotive sector.
Autonomous driving technologies may not require a driver, with the tyres supporting this. Self-driving vehicles support 24/7 operation and allows buses and trucks to operate throughout the night without needing supervision. This could have large economic and societal benefits.
In terms of drawbacks, changing over to the airless tyres could be a slow process. Production costs are much higher compared to pumped tyres and therefore raise initial purchasing costs. Costs most likely will be passed onto the consumer, which could potentially make it difficult for the new tyres to establish themselves within the market.
Going Forward
Introducing airless tyres could have both economic and environmental benefits. Michelin estimates 20% of tyres are discarded due to either flats and rapid pressure loss, along with irregular wear and tear caused by poor tyre pressure. This number adds up to 200 million tyres per year, and two million tonnes of discarded resources.
Airless tyres could massively reduce this number, benefiting the environment as less raw materials will be required to process the same amount of tyres, and benefiting operators as less tyres will need to be purchased.
The tyres are still in testing, but once approved, we could see a massive change to how delivery and trucking services operate, and possibly taking us a step further towards implementing autonomous driving solutions.
