Since the advent of wheeled vehicles, braking systems have traditionally been installed at each wheel to provide individual stopping power. Now, Mercedes-Benz aims to disrupt that age-old design with an innovative approach tailored to the electric vehicle (EV) era.
At its R&D centre in Sindelfingen, Mercedes engineers propose relocating traditional brake components to the centre of the car, housed within the electric drive unit alongside the motor, transmission, and differential. This radical idea could reduce environmental impact, improve ride quality, and redefine aerodynamics.
The Case for Centralised Braking
Modern EVs rely heavily on regenerative braking, minimising the use of traditional brakes except during emergencies. By placing the brake discs centrally within the drive unit, Mercedes seeks to achieve several advantages:
- Environmental Benefits: The aluminium housings would trap brake dust, a significant pollutant, preventing it from dispersing into the environment.
- Improved Ride Dynamics: Centralising the braking system reduces unsprung mass at the wheels, potentially enhancing ride comfort and handling.
- Aerodynamic Gains: Removing traditional wheel-mounted brakes allows for fully enclosed, streamlined wheels similar to those on Salt Flats racers, reducing drag and improving efficiency.
Redefining Braking Mechanics
Unlike conventional systems where pads clamp onto a single disc, the proposed “in-drive brakes” feature two stationary brake discs. These would engage with a spinning, two-sided circular brake pad attached to the driveshaft, offering a compact and efficient design.
Addressing Heat Challenges
One of the key challenges is managing the heat generated during heavy braking. Mercedes envisions integrating coolant directly into the stationary brake discs to dissipate heat effectively. However, finding the right cooling strategy remains a technical hurdle:
- Shared Cooling Circuit: The brake system could share the cooling circuit with the battery and motor. However, compatibility issues arise due to temperature differences—batteries operate at around 85°F, motors at 175°F, while braking systems can reach 300°F or higher. Introducing high-temperature coolant into the powertrain risks overheating sensitive components.
Potential Implications for EV Design
If successful, this system could reshape EV design and performance, offering quieter operation, longer-lasting brakes, and reduced maintenance. Additionally, this concept aligns with Mercedes-Benz’s sustainability goals, addressing environmental concerns while delivering innovative engineering.
While still in the research phase, mid-mounted brakes represent a bold leap forward in vehicle design, showcasing Mercedes-Benz’s commitment to pushing the boundaries of automotive technology.
