Zpětné zrcadlo pro E-Star Changan Benni

This rear brake shoe is suitable for Changan Estar

The rear brake drum of a car is a part of the drum brake system, mainly made of gray cast iron and has wear-resistant properties. ‌

The rear brake drum of a car is an important component of the drum brake system, and its material is generally HT200-300 (gray cast iron). The matrix structure is mainly pearlite with a small amount of ferrite and cementite. The selection of this material makes the brake drum have good wear resistance, but also a certain degree of brittleness, so it may break when encountering aging conditions. The design of the brake drum takes into account the issues of heat dissipation and reducing the temperature of the friction surface. Strengthening ribs are installed to improve the heat dissipation effect, thereby reducing the temperature of the friction surface and shortening the cooling time of the brake, increasing the energy capacity by 35% to 40%. ‌

On the working surface, after the brake drum is assembled with the wheel hub, precision machining is carried out by positioning the bearing holes. For micro cars, the roundness and coaxiality tolerances of the working surface are required to be ≤ 0.03mm, the radial runout is ≤ 0.05mm, and the static unbalance is ≤ 1.5N · cm. These precise requirements ensure the performance and safety of the brake drum. ‌

The working principle of drum brakes is to use the brake transmission mechanism to press the brake shoes onto the inner side of the brake drum, thereby generating braking force to slow down the wheels or stop them in the shortest distance, ensuring driving safety and ensuring reliable parking without automatic slippage. As a part of the drum brake, the rear brake drum pushes the brake shoes to contact the inner edge of the brake drum through hydraulic pressure, and suppresses the rotation of the tires to achieve the purpose of braking through the frictional force generated by the contact . ‌

Although disc brakes have gradually replaced drum brakes in the sedan field in the past thirty years, rear brake drums are still used in some economy cars due to their lower cost, mainly for braking the rear wheels with relatively low load and parking brakes

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