Abstract:Underground where trackless rubber-tyred haulage cars carry out daily operations, hardened surfaces are rare and the roads are often rugged and waterlogged. The vehicles are often required to wade through water in a dusty, muddy, and watery environment. Mud, water and other impurities impair the performance of conventional brakes. Hence, for safety concerns, underground vehicles mostly adopt fully enclosed wet multi-disc brakes, with components fully enclosed to avoid contact with external impurities. This paper introduces the structure and principle of wet brake axles, and outlines the design of brake hydraulic systems.