The self-inflating tire
March 25, 2008 How often do you check your tire pressure? For most of us the answer is "not often enough". Gradual tire deflation over time is a key factor in relation to on-road safety and reduced fuel economy, not to mention the expensive exercise of replacing tires that wear out before the end of their expected life-span. The solution from Czech Republic based CODA DEVELOPMENT s.r.o. is to take the human out of the equation entirely with an integrated system that inflates itself using atmospheric air as you drive.
The Self Inflating Tire (SIT) system consists of a tube chamber integrated into the tire wall that acts as a peristaltic pump, inflating the tire as it turns against the road, regardless of the speed at which the vehicle is traveling. Once a pre-set pressure is achieved a managing valve automatically shuts down any further inflation, resulting in a simple, maintenance free way to keep tire pressure at an optimal level without the use of externally stored compressed air.
A video animation and footage of the system in testing can be viewed here.
According to CODA DEVELOPMENT, driving less than 1 mile on this system will address one months worth of natural leakage (estimated at 1 to 3% per month).
Stats cited on the company's website paint a convincing picture of just how big this problem is - maintaining proper tire pressure would save around 1.24 billion gallons of fuel annually in the U.S. alone, extending the lifespan of the estimated 4.5 million tires that wear out too early due to under-inflation each year and reducing carbon dioxide emissions in the process.
The company plans to develop a production model of the system with auto-industry partners and expects only a marginal increase in production costs to result from integrating the tube chamber between the rim and the tire wall.
The SIT system will be previewed at the 2008 SAE World Congress in Detroit during April.