Continental reinvents the wheel

CONTINENTAL AG, the world’s fourth largest tyre manufacturer, has turned its engineers loose on the humble car wheel in order to help improve, in particular, the efficiency of electric vehicles (EVs).

The radical new wheel, unveiled in Hanover, Germany at Continental’s proving ground before an official launch at the Frankfurt motor show in September, was one of dozens of cutting-edge products unveiled by the company best known for its tyres.

However, the company has extensive operations in automotive componentry grouped loosely into three areas, electrification, connectivity and automated vehicles.

The cutting-edge wheel incorporates an out-sized aluminium brake rotor and the calliper into the overall construction, designed to solve or improve issues associated with the braking systems of EVs.

It is lighter than a set-up using a cast iron disc and the use of hardened aluminium means the disc will not corrode. EVs usually suffer pitting and rust problems with their discs because the energy regeneration systems used do most of the braking, meaning that the discs are not worked hard.

The new wheel consists of the wheel rim, the wheel ‘spider’, a brake disc and calliper.

The design also means there is a saving in weight thanks to the use of an aluminium disc rotor that just fits inside the wheel rim and attached to the underside. The brake calliper is fitted inside the rotor, allowing the rotor to have a huge diameter compared to conventional systems.

“As this disc is corrosion free and we don’t have any relevant wear on the disc, this can stay the lifetime on the vehicle,” said Continental engineer Dirk Eser.

According to Mr Eser, the size of the disc means less pressure can be applied to the disc to achieve the same retardation as a smaller disc.

“There is still friction, but as we have reinforced aluminium, there is really no relevant wear, no wear that would force you to change the disc during the lifetime of the vehicle,” he said.

“In addition, on an EV, you do not brake too much with the friction brake.”

A disc that lasts the life of the car will be cheaper in the long run as cast iron rotors have to be replaced – sometimes as frequently as every two years – because they have been designed to be sacrificial.

“Definitely one of the targets is always to be lower in cost,” Mr Eser said.

“This is always the case. Where we will end up we will see.

“This is not just about a wheel. You’re creating an integrated system that also is included in the overall lifetime cost of the vehicle.”

Mr Eser said he was confident the wheel would be chosen by a car manufacturer in the near future for mass-market manufacturing.

“With this part, it is quite promising,” he said. “We are starting to promote it and you will see in three or four years that this is going to launch into production.”

According to Mr Eser, developments are continuing further with the number of parts required reduced while still allowing for the different rates of expansion between aluminium and steel.