The Active Wheel is essentially a standard wheel that houses a pair of electric motors. One of the motors spins the wheel and transmits power to the ground, while the other acts as an active suspension system to improve comfort, handling and stability. The system is designed for battery or fuel-cell powered electric vehicles, and the technology is such that a vehicle equipped with it will no longer need any gearbox, clutch, transmission shaft, universal joint or anti-roll bar.
Active Wheel’s compact drive motor and integrated suspension system has also enabled designers to fit a standard brake disc between the motors, which means the braking, drive and suspension components are all fitted within the single wheel.
Depending on the amount of power or type of usage desired, a given vehicle may feature up to four Active Wheels for AWD traction. The system also allows torque from the motors to be electronically controlled for each individual wheel independently. The results are similar to the effects of an active differential, allowing a vehicle with Active Wheel technology to make much faster turns in poor conditions than traditional shaft-driven vehicles.
For the suspension, an electric motor controls an actuator connected to a damping system with varying levels of firmness. This unique system features extremely fast response time—just 3/1000ths of a second and all pitching and rolling motions are automatically corrected.
One final benefit of Active Wheel technology is the advantages in passive safety. Since there is no need for a traditional engine in the front of the vehicle, this area can now be entirely dedicated to impact absorption.
Michelin first began development on its Active Wheel more than 12 years ago but is yet to announce when the first commercial applications of the technology will be available. Meanwhile, Venturi’s Volage Concept, which utilizes four Active Wheels, has been confirmed for production in 2012, although it’s not clear if the final production version will share the same features as the concept.