Mercedes-Benz is taking a novel approach to electric vehicle dynamics by applying for a European patent that introduces a double-clutch system within a single electric motor axle. The innovation enables true per-wheel torque vectoring, previously only possible with one motor per wheel, by controlling power distribution independently between left and right wheels.
System Components: Inside Mercedes’ Dual-Clutch EV Torque System
Mercedes-Benz’s torque vectoring system is centered around five key components designed to handle the demands of high-speed electric motors:
- A compact and durable housing
- Two precision-engineered, high-speed clutches
- Hydraulic pistons for clutch actuation
- A control unit for real-time management
- Integration with the electric motor’s drivetrain
Because electric motors routinely spin at 10,000 to 20,000 rpm or more, the clutches in this system are engineered to endure such extreme speeds without structural failure; a key innovation that makes this solution viable.
Selective Torque Distribution At Each Wheel
In most EVs with a single electric motor per axle, torque is distributed using a standard open differential integrated into a single-speed gearbox. In this traditional setup, electronic traction control and software-based torque modulation manage power delivery, often by reducing motor output.
Mercedes’ patented approach changes this. By using two internal clutches within the drivetrain itself, the system enables active torque vectoring, with hydraulic actuators dynamically engaging or disengaging the clutches. This allows torque to be apportioned between the left and right wheels on the same axle, enabling precise, independent power control to each wheel and improving handling, traction, and performance.
Practical Considerations: Regeneration, Cost, and Complexity
While not explicitly stated in the patent, it’s reasonable to assume the clutches would remain locked or partially engaged during regenerative braking to allow for the transmission of negative torque to the wheels.
There’s also no current information on the system’s added weight or cost implications, which are both important factors for manufacturers and buyers alike.
For widespread adoption, Mercedes will need to demonstrate clear advantages in the speed, precision, and overall performance of this torque distribution system. Compared to existing, well-calibrated traction control systems that modulate braking and motor output without added mechanical complexity, this solution introduces new challenges. The inclusion of mechanical clutches adds maintenance demands, as they are wear components that will eventually need replacement.
