Analysis of mini-excavators closed center hydraulic system

Excavator is an important construction machinery, playing an important role in many areas. The hydraulic system is one of the most important systems, as well as one of the most complex systems. As so far, the research and development of the hydraulic excavator technology at home is still in a stage of full backward. As a result, study of the excavator hydraulic system is of great significance.Taking the background of the research into account, this paper made a deep analysis of the hydraulic system of the mini-excavator. Made a description of the excavator’s classification, structure and history, introduced the status and the trend of the excavator’s development, and then gave an analysis of the status and problems of the excavator hydraulic system, demonstrated the importance of the research. Gave a deep analysis of the mini-excavator hydraulic system based on one certain mini-excavator, including the principle of the pump, directional control block, the circuit of the job device and so on. Described the working principle of the load-sensing control systems. Taking the excavating movement of the arm as an example, this paper researched the speed adjusting performance of the flow area. Studied the area property of the U-shaped openning, V-shaped openning and so on. Using AMESim as a platform, this paper made a model of the pump, directional control valve, pressure compensated valve, and the job device. After the simulation of the individual and implementing actions of the non-load state, the model gave a satisfactory result, and thus provided an important reference for the research of the excavator. Put forward some suggestions on optimizing flow areas.