【Listening】

【Vocabulary & Phrases】

braking system（制动系统）

service brake（行车制动器）

parking brake（驻车制动器）

brake pedal（制动踏板）

handbrake（手刹）

brake shoe（制动蹄）

brake pad（制动片）

brake drum（制动鼓）

brake disc（制动盘）

disc brake（盘式制动器）

caliper（制动钳）

【Reading】

BrakeSystem

The braking system is the most important system on acar. If the brakes don't work properly, the result can be disastrous. So thegood brakes are essential for safety.

There are two completely independent braking systemson a car. One is the service brake, and the other is parking brake. The servicebrake acts to slow, stop, or hold the vehicle during normal driving. They arefoot• operated by the driver depressing and releasing the brake pedal. Theparking brake's purposes are to hold a car stationary while it is unattended,and to keep the car from rolling on unleveled ground. It is also called thehandbrake.

Basically, all car brakes are friction brakes. Whenthe driver applies the brake, the control device will force brake shoes or padsagainst the rotating brake drums or discs at wheels. Friction between the shoesor pads and the drums or disks then slows or stops the wheels so that the caris braked.

Discbrake

Disc brakes are used on the front wheels of mostcars and on all four wheels on many cars.

The main components of a disc brake are the brakepads, the caliper which contains a piston, and the rotor which is mounted to thehub.

The disc brake is a lot like the brakes on abicycle. Bicycle brakes have a caliper, which squeezes the brake pads againstthe wheel. In a disc brake, the brake pads squeeze the rotor instead of thewheel, and the force is transmitted hydraulically instead of through a cable.Friction between the pads and the disc slows the disc down.

A moving car has a certain amount of kinetic energy,and the brakes have to remove this energy from the car in order to stop it. Thebrakes convert the kinetic energy to heat generated by the friction between thepads and the disc, so the car stops.

拓展视频

【Speaking】

Role play the dialogue with your partner！