Research Of The Structure And Performance Of The Wind Power Gear-box Transmission System Above MW Level

With the rapid development of the global renewable energy market and the strengthening of the human's environmental awareness, people begin to focus on the new energy development. The wind power has become a new growth point of the energy industry. As an important component of the wind turbine in power transfer,the structure and properties of the transmission system in the gear box directly affect the normal operation of the wind turbine. Structure of the gear-box in the transmission system determines the overall volume of the gear-box. During operation of the transmission system, the power source is natural wind which changes all the time. This is bound to cause the transmission system vibration. In order to reduce the volume of the gear- box of the wind power, the vibration of the drive system and the noise, it is necessary to carry out the structure and mode analysis on transmission system of the wind power gear-box. The paper includes selection and optimization of the 1.5MW gear box transmissionsystem structure of the wind power, considering the time-varying character of the gear mesh stiffness, the external incentives, the internal incentives and other factors, and establishes the torsional vibration dynamics model of the transmission to the optimized. On this basis, the free vibration linear differential equations of multi degree of freedom is built and solved so as to obtain the natural frequency and the main vibration mode of the transmission system. It establishes basis for the next step research on dynamic response of the transmission system.The work done in this paper is listed as below:(1) Design of our transmission system adopting the power split three planetary gear mechanisms with the third stage as the differential planetary gear. Taking the total volume of the planetary gears as the objective function and teeth number of the sun wheel and related scale factor as the design variables, optimization of the transmission system is done using the toolbox function in the MATLAB. And finally get the ultimate number of teeth of the sun gear and the related factors.(2) Calculation of the modulus each level. Establishment of the three-dimensional model of the planet gears, the planet carrier, the axis and assembling of them together to construct the three-dimensional model of the transmission system.(3) Building of the dynamic torsional vibration model of the transmission system in the gear box using the lumped parameter method, the meshing gears are equivalent to a spring and a damper. Ishikawa method is used to calculate the gear mesh stiffness. Related calculation is conducted on meshing stiffness of the second stage sun gear and planetary gear. Using Lagrange equation is derived the torsional vibration differential equation of the transmission system is derived using the Lagrange equation.(4) Establishment of the free vibration linear differential equation with 16 degrees of freedom of the transmission of the gear box , and obtaining of the natural frequency and main vibration mode using the EIG command in the MATLAB.The research mentioned above provides a reference to the design of gearbox in wind turbine, on the requirement of light weight, low cost, and fits the power requirements.