Continental continues to design brake calipers for electric vehicles. New generation ‘Green Caliper’ disc brake calipers, which have now been introduced, are much lighter than previous technology and have lower residual drag torque. In two or three years, the system could reach production cars.
In combination with the brake disc, the lower mass and reduced friction between the pad and the disc can increase the range of electric vehicles by around 1%, according to Continental.
Only the new brake caliper is up to 2 kg lighter. The system saves up to 5 kg of weight per brake in individual cases.
Unlike the brakes of a conventional vehicle, those of an electric car are activated much less frequently. Indeed, in more than 80% of deceleration situations, the brake is not necessary at all due to recuperation, i.e. the recovery of energy during deceleration by the electric motor.
However, due to the weight of the battery in an electric car, the deceleration power of the brakes often has to be greater.
On the other hand, its thermal load is lower because the brake is much less stressed.
Continental has designed the construction of its new brake caliper for this changed requirement profile.
According to the developers, the cast iron caliper of the Green Caliper is much more compact, the brake pads are smaller and thinner because they wear less quickly. This reduces the mass of the caliper.
At the same time, the smaller caliper with its lower bridge height allows the installation of a larger but thinner cast iron brake disc.
Due to the lower thermal load, the disc can be made much thinner, which saves more weight.
Since the brake engages further on the larger disc and thus achieves high deceleration performance with the same clamping force thanks to the longer lever arm, the braking performance is at the same time “optimal”. .
Also in the interest of driving efficiency, the green caliper has an active return of the brake pads after each stop. This reduces the residual drag torque between the pads and rotor to less than 0.2Nm, which means nearly lossless operation.
Another design innovation ensures that the air gap between pad and rotor is larger and is evenly distributed on both sides of the brake.
Increasing efficiency is a primary goal in optimizing electric vehicles. The lower the loss of electrical energy, the greater the range of the vehicle. Brakes can make a contribution that has not been exploited so far. With the new Green Caliper, we are delivering production-ready technology that unlocks further potential for electric car autonomy.
Dominik Hiss, Friction Brake Product Center Manager, Continental Hydraulic Brake Systems.
