At the recent auto, motor und sport-Kongress 2013 in Stuttgart, Schaeffler presented the latest development version of its E-Wheel Drive electric wheel hub drive. The in-wheel drive is applied in a Ford Fiesta-based development vehicle created in cooperation with Ford.
The compact vehicle is driven using two Schaeffler E-Wheel Drives that are installed in the rear wheel arches. All components—the electric motor, power electronics, controller, brake, and cooling system—are installed inside the wheel rim.
|Click to enlarge.|
The in-wheel drives offer peak output of 40 kW, 33 kW continuous. The liquid-cooled wheel hub drive, which is in its beta stage of development, also delivers up to 700 N·m (516 lb-ft) of torque. In comparison to the first-generation wheel hub drive, which was first exhibited in Schaeffler’s Opel Corsa-based Schaeffler Hybrid concept car in 2010, the E-Wheel Drive beta features an output increase of one-third, as well as 75% more torque. The electrical voltage of the high-voltage drive is 360 – 420 V.
The highly-integrated wheel hub drive has a total weight of 53 kg (117 lbs), so the weight increase compared to a conventional wheel with a wheel bearing and brake is 45 kg (99 lbs). It has a 16-liter design envelope, which is housed inside a 16-inch wheel rim.
Overall, we were able to reduce the vehicle weight once again because, in addition to the liquid cooling, the power electronics and controller can now be integrated into the wheel, which means that the complex wiring in the vehicle can be omitted.—Dr. Raphael Fischer, Director of the Wheel Hub Drives Product Group
Schaeffler’s E-Wheel Drive is now also part of a research project that is listed by the Federal Ministry of Economics and Technology.