Research On Cutter Head And Its Hydraulic Drive System Of Shield Tunnelling Machine

As a large excavated equipment, earth pressure balance shield is widely used in tunnels, municipal engineering, Bridges, roads, railways, etc. It integrates hydraulics, electrics and measurement, civil, machinery and so on, which is a product of high-tech development. Cutter head is the key part of shield that locates in the front of shield undertaking the functions of excavation, stirring and stability. According to different geological conditions, the structure of cutter and configuration of cutter tool are different. And in domestic, the relevant design theory about cutter head and drive system of earth pressure balance shield is lack. So it is necessary to research on cutter head that can provide theoretic help for shield's design and manufacture.In this paper, first of all, the diagram of hydraulic drive system for cutter head is designed, the working principle is elaborated and design parameters are calculated. Secondly, the system is modeled in the environment of AMESim and simulated which imitates the actual situations, the simulated results show that the hydraulic drive system can meet the practical requirements. The structure of cutter head is researched. The three typical cases are analyzied based on the virtual prototyping model of cutter head. On this basis, some local deficiencies are optimized. The optimil results show that the performance and safety of cutter head are better than before. Finally, the mathematical model of cutter head's torque is established after full considering the affecting factors, then the mathematical model is simulated on the simulator test rig, the experimental results show that the model is more accurate. The main contents of each chapter are summarized as follows:In chapter one, the developing history of shield machine and research status are expounded, the current drive system of cutter head and structural status are discussed, then, the research task of this paper are put forward.In chapter two, the hydraulic system of cutter head which is drived by three pumps is designed according to the design requirements. Then the working principle of cutter head is explained in detail, the main design parameters such an pressure, flow, power and torque are calculated, the calculated results show that this system satisfies the requirements of system. In chapter three, the AMESim model of system is overlapped according to the diagram of hydraulic drive system of cutter head, and the corresponding parameters are set. The speed-load, relief, load fluctuation and motor invalidation are simulated, and the simulated results show that the system can meet the construction requirements.In chapter four, aiming at the requirements of the soft layer in the tunnelling constructions, a virtual prototype model of shield cutter head with diameter of 6.34 meters was designed using Pro/E software, and the cutter head,cutter tool,cutter seat were also virtually assembled. Meanwhile, the three typical working conditions of the cutter head model was analyzed in the environment of ANSYS. The structural parameters of cutter head were optimized based on the analysis.In chapter five, the main research contents of text is summarized and several opinions of future research work are put forward.