S-Cam
An S-cam (S-camshaft) is a key component in drum brake systems, commonly used in large trucks and trailers. It consists of a camshaft with an S-shaped curve that rotates when the brake pedal is applied. This rotation pushes the brake shoes outward against the drum, creating friction to slow down or stop the vehicle. The S-cam design ensures even pressure distribution and helps maintain effective braking performance.
Key Trailer Air Brake Components
Air Compressor: Generates compressed air.
Air Tank (Reservoir): Stores compressed air.
Brake Pedal: Activates the braking mechanism.
Valves: Controls the flow of compressed air.
Brake Chambers: Converts compressed air into mechanical force.
Brake Drums: Generates braking force to slow or stop the vehicle.
Brake Shoes or Pads: Applies pressure to the drums or rotors to create friction and stop the trailer.
S-Cam: Spreads brake shoes apart to apply pressure to the drums.
Slack Adjusters: Multiplies the push rod force by the slack length to create a rotational force (torque) to rotate the brake camshaft when the brake treadle is depressed.