Ever since the issue of air resistance began to play a serious role in automotive engineering, experts have been working on concepts to minimize air vortices at fast-moving wheels. After all, these vortices are responsible for a not inconsiderable increase in overall air resistance and thus for greater energy consumption. The wheels of electric vehicles that are particularly trimmed for efficiency therefore often feature closed rim designs with at most smaller openings, as these help to reduce air resistance in the single-digit percentage range. More would be possible, but only closing the rim completely could more effectively stop the flow of air and the damaging rotor effect of the wheel. This, in turn, is in direct conflict with the necessary cooling of the brake chamber, especially in cases of higher loads, for example when descending a pass.

CompActive GmbH, a young technology company based in Neustadt an der Weinstraße and as such specializing in the development and production of actuators, has now tackled the problem and will be presenting its approach for the first time at HANNOVER MESSE 2022. With the help of bending actuators developed in-house, a particular specialty of CompActive, the company has succeeded in integrating several ventilation flaps into a rim. These open automatically due to the waste heat from the braking system, thus introducing the necessary cooling through the wheel surface when required. Since this solution does not require an external energy source, it can also be easily applied to the rotating components. According to CompActive, the flat bending actuators not only offer sufficient travel, they are also said to have the necessary robustness to withstand the rough and tumble of everyday road traffic.

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