AUMOVIO has developed a semi-dry brake system that combines electromechanical braking with a conventional hydraulic front axle, using active brake-pad clearance to reduce residual drag in electric vehicles (EVs).
The system uses a near-production electromechanical brake on the rear axle. Instead of relying on hydraulic pressure, an electric motor actuates the rear brake caliper, eliminating the need for hydraulic lines and brake fluid at the rear wheels.
One of the main engineering advantages is active control of the air gap between the brake pad and disc. The electric actuator can reopen the caliper after braking and maintain a consistent clearance, reducing the residual braking torque that can occur when pads remain close to the disc.
The air gap can also be adjusted according to vehicle conditions. A larger clearance can reduce drag during normal driving, while the system can reduce the gap when faster brake response may be required.
At the front axle, AUMOVIO uses its MK C2 brake-by-wire system with modified hydraulic calipers designed to establish a larger air gap more quickly. The system electronically determines when friction braking is required and when braking demand can instead be handled through regenerative braking.
The semi-dry architecture also creates opportunities to reduce vehicle weight and simplify packaging by removing hydraulic hardware from part of the braking system. AUMOVIO says a fully dry configuration using electromechanical calipers at all four wheels could extend those benefits further.
The braking technology is being evaluated in Volkswagen’s Mission Efficiency EV, based on the ID. Polo, as a near-production demonstration of how lower brake drag can contribute to overall vehicle efficiency.
Filed Under: Technology News