Very Large Mining Dump Truck Fully Hydraulic Wet Braking System Features

Mining Truck gradually develops toward large-scale, and dump trucks over 300 tons have been become the mainstream transportation equipment of large open pits over the world, played an important role in mining. According to the national energy strategy, the development of ten million tons large open coal mine is one of the important direction of coal energy base construction in future, and large dump truck has been listed in the national "important technical equipment" field. After the dump truck full loaded, because its heavy weight, high speed and bad driving environment, mining truck must has a reliable braking performance. Hydraulic brake system performance will directly affect the driving safety and the braking reliability. Most foreign large dump trucks use full hydraulic wet brake system, while the domestic research is lack in this theory.The brake system of 300 tons electric dump truck was taken into account in this paper. And the full hydraulic wet brake system was researched systemically by means of theoretic analysis, numerical simulation and experimental. The main research work are as follows:(1)The paper analyzes the overall scheme of full hydraulic wet brake system of 300 tons electric dump truck, and studies working characteristics of braking control system and heat dissipation characteristics of the cooling system.(2)The dynamics model of system's braking process was analyzed to reveal the motion law of hydraulic brake system actuators and the essential relationship between each hydraulic components, and SIMULINK simulation models of hydraulic braking control system were established to analyze the whole braking characteristics focused on the braking system dynamic response characteristics and dynamic characteristics of braking pressure pressurization process.(3)The FLUENT calculation model of wet multiple disk brake cooling oil was built in the base of heat transfer characteristics'analysis of forced cooling process of wet brake cooling system. The transient temperature field was studied in extreme braking condition and found out the cooling oil highest temperature beyond the control range. Therefore the paper puts forward some measures and conducts comparative study of them. The influence of oil temperature on dynamic characteristics of brake system was researched in the base of the analysis of oil temperature field.(4)The experimental research of dynamic characteristics of full hydraulic braking control system was carried out, and experimental results verifies that dynamic model of braking process and research results of dynamic characteristics is accurate.