Research On Two Stage Compound Planetary Gear Sets Used In High Power Ship

Along with the development of the modern naval ships fighting capacitie, the level of vibration and noise is incresing. The structure design level of the after transmission sets directly related to the characteristics of the torque and power.The two stage compound planetary gear train is one of the most important equipment in after transmission. The entire system is composed of a star gear system with fixed carrier and a planetary gear system. Changes of the dynamic characteristics can easily produce vibration and noise problems which are also the main noise source of machine equipment. The fighting abilities are greatly affected by the vibration and noise.As the existing ship transmission system is very large, the experimental test can not be carried out in our country. Therefore, the dynamic properties of theory study is very necessary.The dynamic characteristics of the two stage compound planetary gear transmission system are more complicated than a single-stage transmission. The dynamic research on the two stage connection compound planetary gear is notably lacking in the literature. The dissertation mainly studies the dynamics of the two stage compound planetary gear. Some key issues such as nonlinear dynamic modeling, natural vibration properties, eigensensitivity, frequency veering, solution methods and dynamic behaviors of the system are concerned.In the present case, there are potentially several different carriers, each rotating at different speeds. It is possibility is to describe all components in a single fixed basis and then allow the planet position angles to change with time. The nonlinear dynamic model of two stage compound planetary gear train with time-varying planet position angle, time-varying mesh stiffness, error excitation, damping, gear compression and tooth separation is constructed by using lumped parameter model under the fixed coordinate system. For the purpose of dynamic analysis, the meshing stiffness and error are determined. Under the condition of all the points on simultaneous engagement contact line have the same deformation, the meshing stiffness of a pair of herringbone is obtained. The composite meshing error is described by the form of contact line increments.Natural vibration characteristics are composed of natural frequencies and vibration mode which have significant impacts on dynamic response, dynamic load generation and transmission, as well as the vibration forms. Through the analysis and calculation of natural frequency and vibration mode, all vibration modes for system are classified into three types which are called star system vibration mode, planetary system vibration mode and coupling vibration mode. The properties of the modes, which have been drawn from numerical results, are studied with equal and unequal planet spacing.Based on the mode method, the eigensensitivity calculation model of the two stage compound planetary gear system is established. The model is greatly simplified by the introduction of the unique natural vibration characteristics. The system through two meshing stiffness and torsional stiffness of connected shaft between the two natural frequencies of the sensitivity study, obtained the parameters change on the natural frequency of each vibration mode were investigated. Modal Energy to introduce the definition of a more intuitive characterization of a natural frequency of the various parameters of sensitivity to change. On this basis, the word on the two series planetary gear hybrid powertrain carried out an analysis of the phenomenon of modal transition obtained belong to different natural frequencies of vibration modes, the natural frequency changes of mode transitions, and verified by examples the correctness of the conclusions.To solve the two series hybrid drive system dynamic equation of planetary difficult problem to solve, using incremental harmonic balance method and the arc-length continuation techniques, and its application to this paper, the system dynamic equations to arrive at the system The working speed components in the vicinity of the frequency response characteristics. The multi-scale perturbation analysis method applied to two series hybrid drive system to solve the planet, respectively, were the main harmonic resonance, subharmonic resonance and ultra-harmonic resonance frequency response of three cases equation, and calculated the The main system of amplitude-frequency characteristic curve. In the above two methods of analysis process, are obtained for the system dynamics and numerical method results were compared to verify the feasibility and effectiveness of the proposed method.Numerical method on the system non-dimensional kinetic equation is solved, first through the displacement of the time domain response, phase diagram, Poincare map and bifurcation diagram of various analytical techniques, the system response characteristics of nonlinear dynamics have been studied and found steady-state response to a variety of inter-conversion laws. Next, focus on the system parameters change on the dynamic characteristics. Studies included in the system parameters are meshing stiffness (amplitude and harmonic number), mating an integrated error (amplitude and harmonic number), damping ratio of 2 between the torsional stiffness, gear helix angle and the external load. The various components through the analysis of amplitude-frequency characteristic curve obtained two series hybrid planetary transmission amplitude-frequency characteristics of the unique dynamics for such systems provide a basis for the design and experiments...