What is the Braking Principle of Disc Brakes?
2 Answers
During braking, hydraulic fluid is forced into the inner and outer wheel cylinders, and the pistons press the two brake pads against the brake disc under hydraulic pressure, generating frictional torque to achieve braking. This is the working principle of disc brakes. Disc brakes mainly come in two types: full-disc and spot-disc. In full-disc brakes, both the stationary and rotating elements of the friction pair are disc-shaped, referred to as the stationary disc and rotating disc, respectively. The entire working surface of the brake disc can simultaneously contact the friction pads. In spot-disc brakes, the brake pads and their actuating devices are mounted in a caliper-shaped bracket that spans both sides of the brake disc, known as the brake caliper. Caliper disc brakes have strong heat dissipation capabilities and excellent thermal stability. Disc brakes are now widely used in passenger cars. Most cars use them on all wheels, while a few use them only on the front wheels, paired with drum brakes on the rear wheels.
The braking principle of disc brakes relies on the caliper clamping the rotating brake disc to generate friction, thereby slowing down the vehicle. When the brake pedal is pressed, the brake fluid pushes the pistons inside the caliper to move, causing the brake pads to tightly press against the brake disc. The friction converts the vehicle's kinetic energy into heat, which is dissipated, ultimately bringing the wheels to a stop. I find this design quite practical—for example, during frequent braking on downhill mountain roads, it’s less prone to overheating, ensuring stable and safe braking. However, it’s important to monitor brake pad wear. If the pads become too thin, braking performance may decline, so it’s recommended to inspect and replace them every 20,000 kilometers. Disc brakes dissipate heat much faster than drum brakes, making them more reliable on wet or slippery roads and reducing the risk of skidding accidents. It’s also a good habit to listen for unusual noises or vibrations while driving daily, allowing for early maintenance.
