Protean in-wheel electric motorEnlarge Photo
As electric cars become more prevalent in the market place, many automakers are still exploring the best way to make use of electric drivetrains. We've seen everything from plug-in hybrids through front-drive electric cars like Nissan's Leaf, to more advanced offerings like the four-wheel driven Mercedes SLS AMG Electric Drive.
In-wheel electric motors are another avenue and one that Volkswagen is now exploring, teaming up with specialists in the field, Protean. Protean has been developing in-wheel motors for several years now, demonstrating its wares on vehicles like the BRABUS Technology Project Hybrid and announcing a production electric in-wheel motor earlier this year. In the latest venture, says Green Car Reports, Protean and FAW-Volkswagen--a Chinese arm of VW--will develop a rear-wheel drivetrain for a new electric Bora compact sedan.
The Bora--a rebadged version of the Jetta--will develop 100 horsepower from each motor, which weigh 75 pounds each. Fans of unsprung mass will remain unimpressed, but Protean claims the motors have the highest torque density of any of today's leading electric drive systems. There's also no need for any extra weight outside the car's battery to be stored around the car, as the motors' power and control electronics are packaged within the motors.
As part of the wheel assembly, regenerative braking energy is high, collecting up to 85 percent of the vehicle's kinetic energy during braking, while the whole assembly fits inside wheels of 18-inch diameter. Despite the in-wheel weight penalty, 100 horsepower per motor is somewhat impressive, and we're more than a little intrigued by the concept of a high torque, rear-wheel drive Volkswagen Jetta...
FAW-Volkswagen and Protean have actually been working on the project for some time now, so development and testing is well underway--so the companies say that all bench testing, engineering calibration and on site application support is expected to be completed "within a year"--corresponding with Protean's previous promise to move to full production in 2014.