What is the difference between air brake and wet brake?

The air brake and wet brake of mining dump trucks are two different braking systems, which differ in principle, application occasions and characteristics:
1. Air brake (pneumatic brake):
Principle: The air brake mainly relies on the pressure of compressed air to push the brake mechanism to move. When the air pressure disappears or drops to a certain value, mechanical forces such as springs or gravity will automatically brake the vehicle. It is achieved by cutting off or releasing the air pressure through the valve controlled by the driver to achieve braking and release.
Application occasions: Due to its high reliability and strong braking force, it is usually used in large trucks, buses, engineering vehicles, etc., especially in environments where heavy loads and frequent braking are required, such as mining dump trucks.
Features: The braking effect is stable and the maintenance is relatively simple, but it is highly dependent on the air source system, and it is necessary to regularly check the air tank pressure and the sealing of the pipeline.
2. Wet brake (disc brake or wet disc brake):
Principle: In the wet brake system, the brake disc is partially immersed in coolant (usually oil). When braking, the caliper pushes the brake pad to clamp the brake disc, generating braking force through friction. The presence of coolant can not only enhance the heat dissipation effect, but also reduce wear and noise.
Applications: Wet brakes are particularly suitable for long-term continuous heavy-load braking conditions due to their excellent heat dissipation capacity and low wear rate, such as underground mining dump trucks that need to brake continuously when going downhill.
Features: It can effectively reduce thermal decay, extend the life of brake components, and improve braking safety, but the structure is relatively complex, the maintenance cost is high, and the quality and amount of coolant need to be checked regularly.