Archive for the ‘Continental Tires’ Category

Continental rethinks the wheel—and the brake—for electric cars

August 25th, 2017

Enlarge (credit: Continental)

When it comes to making a car slow down, for the last few decades pretty much every car on the road has used the same idea: a brake disc mounted to the axle with calipers that press high-friction pads onto the disc’s surface, slowing its rotation. It’s a tried-and-tested formula, one that car makers adopted from the aerospace industry as a better solution than the venerable drum brake. But the boffins at Continental (the tire company) have been rethinking the standard way of doing things, specifically in the context of small and medium-size electric vehicles. Enter the New Wheel Concept.

The focus on EVs is logical, since in their case deceleration is often achieved via regenerative braking using the electric motor instead—at least on the driven wheels. Obviously, EVs can’t ditch the conventional brake, there needs to be redundant system for situations when regenerative braking isn’t possible like when the battery is full and can’t accept more energy. A consequence of using regenerative braking is that the friction brakes get much less use than in a conventional car, so they tend to last a lot longer. But there is a downside: a buildup of rust that can impair their performance when you need to use them, according to Continental. (This is only an issue with cast iron brakes, but we’re not aware of many hybrids that use carbon ceramic discs outside of the hypercar crowd.)

“In EVs, it’s crucial that the driver expends as little energy as possible on the friction brake,” said Paul Linhoff, Head of Brake Pre-Development in the Chassis & Safety Business Unit at Continental. “During a deceleration, the momentum of the vehicle is converted into electricity in the generator to increase the vehicle’s range. That’s why the driver continues to operate the brake pedal—but it certainly doesn’t mean that the wheel brakes are active too.”

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The secret ingredient in Continental’s future tires? Dandelions

October 28th, 2016

Enlarge (credit: Aurich Lawson)

Let’s talk about tires. As the only part of our cars that actually touch the road they’re obviously incredibly important, but few people consider them much more than boring round black things. That’s not entirely surprising. While most car companies will wax rhapsodic over their latest and greatest bits of technology, their colleagues on the tire side of things tend to be much more inscrutable. Here’s a fact that surprised me recently: did you know that even now in the 21st century, between 10 and 30 percent of the rubber in the tires you can buy still comes from trees? Although tires also contain synthetic rubber in them, the complex long polymers formed by Mother Nature provide much better wear characteristics

The fact that all of our vehicles are dependent upon latex tapped from trees is not ideal. The rubber tree (hevea brasiliensis to its friends) only really grows in certain locales near the equator, and that means supplies are under threat from climate change and also sometimes hostage to unstable governments. For the past few years, Continental has been looking for alternatives, and the company believes it’s found one in an unlikely source: the Russian dandelion.

“We’ve been looking into the idea for at least the last five years,” explained Dr. Peter Zmolek, one of Continental’s engineers working on the project. “Fairly recently we started going into it with a more serious approach—building tires—and more recently we’ve committed to investment in a facility that would allow us to start making it on a more productive scale.” Continental wanted to find a material that was close enough to natural rubber trees that it would allow them to just drop the material into their tire production process, which meant finding a plant that made the right kind of latex.

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