| With the rapid development of modern urban underground traffic and railway construction, TBM has been playing a major role in all kinds of hard rock tunnel engineering with long distance and large buried depth. In recent years, there have been someattemps of research and design for domestic-made TBMs to get rid of the dependence on foreign technology import. Planetary gear transmission has many advantages, such as its compactness, light weight and high-transmission efficiency. Hence, it is not only a choice for the main reducer of TBM, but also widely used in all kinds of high-speed, large power, and low-speed, high torque applications. In order to adapt to the development requirements of high-speed, overload, high-reliability and high precision transmission, the dynamics of multistage planetary gear system has drawn more and more attention in industry.One main reducer of TBM is considered as the research object. Dynamic characteristics and vibration behavior of the planetary gear transmission system are analyzed based on the theory of gear dynamics, finite element ideas, and numerical method. A test bench was built for researching the vibration characteristics. Consequently, more comprehensive dynamic characteristics are obtained through the combination of theory analysis and experiment results. Here are the main contents:(1) Aimed at the problems of lower calculation accuracy of lumped mass method and large-scale computing, difficult post processing of finite element model, a novel coupling vibration analysis method for multistage planetary gear system is presented. The various components in planetary gear system are divided into three shaft models, those are simple shaft unit, planet carrier shaft unit and ring gear shaft unit, according to the structure characteristics of planetary gear system. Different types coupling dynamics model are established for planetary gear system after considering the influence of flexible structure.(2) The natural frequency and vibration mode of the preceding model are calculated according to the calculation principle of inherent characteristics. Several distinct vibration modes are summarized, such as planets torsional vibration mode, sun-gear shaft axial vibration mode and so on. Furthermore, the sensitivities of inherent characteristic to the system parameters such as meshing stiffness are studied.(3) Stationary response of nodes both in time domain and frequency domain are solved, and the coupling characteristics and the vibration transfer law of multistage planetary gear system are obtained. And then the influence of flexible structure on dynamic meshing force is studied. The vibration response of nodes and the dynamic meshing force are analyzed under different types of mutation load condition. Consequently, the response characteristics of multistage planetary gear system under transient conditions are obtained.(4) The vibration test experiment platform of the main reducer of TBM is built on the basis of theoretical analysis for studying the vibration response under different working condition. Time history of vibration displacement and vibration acceleration of different measuring points are gathered and analysed. Finally, the experimental analysis and theoretical results are compared, and the rationality of planetary gear transmission system dynamic model established through shafting element method is verified. |
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