Analysis Of Vibrational State Of Gearbox System About Wind-Driven Generator

Increasing gearbox whose vibration state affects the operation performance of wind generator system is one of the most important parts of wind generator system. This paper studied the kinematics increasing gearbox to know its kinematics character, studied the dynamics analysis of increasing gearbox of DHI.DCW Group Company by using the FEM software and vibration tests to determine the measuring points.Firstly, the background, significance, situation and development trend of the project is presented. And the structure of increasing gearbox of wind generator is studied. Structure sketch of increasing gearbox is produced. Kinematics and characteristic frequency of the increasing gearbox is analyzed.Secondly, the three dimensional contact finite element model of the third gear transmission system is established. With this model, the instantaneous stiffness of gear tooth could be calculated for multi-tooth meshing and the curve of gear meshing stiffness is fitted by using the curve fitting of Matlab. Based on this, nonlinear dynamical equation of gear transmission system is established, and solved by using the Runge-kutta method. The influence of stiffness excitation on system is discussed.The three dimensional finite element model of output gear-shaft is established, and the terminal bearings are simulated by spring elements. The vibration states of output gear-shaft on stiffness excitation are obtained by finite element dynamic analysis.Thirdly, the three dimensional finite element model of the gearbox is established. A modal analysis of the gearbox is carried out, and obtains the vibration characteristics. Based on this, the influence of stiffness excitation on gearbox is calculated and discussed by using modal superposition method. And the vibration forms of some key points are carried out.Based on the above theory, locations optimization of the measuring points in monitoring of vibration are set up, and the feasibility is proved by experiment. These works have established a good basis for the study group to do the next research.