ZF now offers a new, purely electro-mechanical brake system, where braking force is generated at each wheel by an electric motor without using a hydraulic system or brake fluid. The brake system was established at ZF’s development centers in China, the USA, and Germany for the global market.
“Our electrically controlled braking system is a significant addition to our portfolio of networked chassis systems,” said Dr. Holger Klein, CEO of ZF. “Using by-wire systems, we are opening the door to a new era of vehicle control. This is especially true in software-defined and electrically driven vehicles, where this type of brake system has even more advantages and opens up new freedoms in design and development.”
In a “dry” brake system, brake fluid is not required. Brake pressure is no longer generated by the pressure of fluids in the hydraulic system, but by electric motors. Brake signals from the pedal to the electric motor are also transmitted purely electrically, a system referred to as a dry brake-by-wire.
Compared with conventional braking systems, the new brake-by-wire system enables shorter braking distances, better recovery of braking energy, and lower maintenance costs. During automatic emergency braking, braking distances at a speed of 100 km/h can be up to nine meters shorter than with conventional braking systems.
In addition, electric cars can achieve up to 17% more range due to better recuperation of braking energy.
The residual drag torques from contact between the brake pads and the brake discs that occur in conventional systems are reduced to almost zero in dry brake-by-wire systems. This results in even fewer particulate emissions due to brake abrasion. This lower resistance during driving also saves energy and can even increase the range of an electric vehicle (EV).
Dispensing with a hydraulic system means significantly lower assembly and logistic costs during vehicle production, as the system consists of fewer parts. The user also benefits from no longer needing to change brake fluids, reducing the amount of servicing required. Even though there is no longer a mechanical connection between the brake pedal and the brake actuators, the braking feel is the same as that of a hydraulic brake.
The safety of the data transmission, processing, and energy supply to the electric motors is ensured by the duplication of all connections and systems.
Vehicle manufacturers now have the opportunity to transform their optimum braking system from the classic, purely hydraulic, to the new, purely electric braking system. Hybrid forms with, for example, a hydraulic system at the front and a purely electric system on the rear axle, are also possible. ZF ALSO offers all components of a braking system from a single source, from wheel brakes to parking brakes, and hardware to software. ZF has a comprehensive portfolio of purely electronically controlled steering, brakes, and damping systems for software-defined vehicles.
“Networked chassis systems for longitudinal, lateral, and vertical dynamics can improve driving dynamics,” said Klein. “ZF is uniquely positioned in the market with its range of actuators and functions for combining all three dimensions of vehicle dynamics as well.”
Filed Under: Technology News