Drum Brake
A drum brake slows a wheel by pressing friction shoes against the inside of a rotating drum.
Why some EVs use them
The enclosed design can protect the friction surfaces from some contamination and integrates a parking-brake function compactly. Heat rejection and repeated high-load performance are generally less favorable than with an exposed ventilated disc, so drums are often used on lightly loaded rear axles.
Adjustment mechanisms keep the shoes close to the drum as their linings wear, while springs retract the shoes after brake pressure is released.
Regenerative braking can reduce rear friction-brake use, making durability and corrosion resistance attractive design priorities. The complete vehicle must still meet braking and stability requirements. A drum brake is a form of friction braking, not a regenerative device. braking systems