Stuctural Lightweight Design For The Key Parts And Components For Large Megawatt Wind Turbine

Wind gearbox is the key component of wind turbine. Under the premise of meeting high transmission power, demands for the volume and structure of the wind gearbox, which is from the rapid increase of the wind turbine capacity, are more stringent than before, so that the traditional structural design of gearbox based on experience couldn’t meet the design requirements of large megawatt-level wind gearbox any more. The modern methods of structural design, such as finite element analysis, size optimization and topological optimization are applied to the design of the key parts and components of the wind gearbox, which improve design efficiency and enhance the core competitiveness of enterprises. The structural performance analysis and optimization design of the key parts and components of the large megawatt-level wind gearbox has been achieved in this paper combined with the content of the research subject. The specific contents are contained as follows:(1) According to the design conditions, the analysis of gearbox configuration is presented in three aspects, which contains total ration, carrying capacity and space volume, and the RR scheme as design configuration is decided to adapt to this paper. The transmission characteristics of motion component and static analysis of fixed component are researched based on the above.(2) The planet carrier of first stage and front component are taken as research object of structure optimization based on the characteristic of the RR transmission scheme. The finite element model of the key components are built and analyzed, in which the load distribution and constraint condition are combined. Parameter sensitivity analysis is carried out for structural parameters that have influences on static performance of the key parts and components.(3) The evaluation indicator of the static performance of the key components of the wind gearbox is put forward based on the analysis of the structural performance. Topology optimization model of planet carrier based on the weighted compliance optimal objective is built; meanwhile the front gearbox model based on the multi-position load cases and multi-objective of static and dynamic performances is built. The design of structural concept is achieved based on the force path of topological optimization.(4) The analysis of conceptual model of planet carrier is presented in many performance indicator, which contains displacement, the first principal stress and so on, and surface structure as design object is decided to adapt to size optimization of planet carrier.The double-objective and the key structure parameters as the optimized variables size optimization model for the key components of wind gearbox is established pass through size optimization. Parameter sensitivity analysis is carried out, and the best combination scheme which include the key design parameters is acquired.Compared with the original planet carrier, many indicators of static performance of the optimum one has changed, such as the mass and the first principal stress are respectively reduced13.42%and29.97%, the ratio of stiffness plan for the condition Y direction, Z and comprehensive direction respectively increases1.63%,5.7%and4.41%. The change of the first principal stress of front gearbox is very small, however, separately with the mass reduced12.79%and the ratio of stiffness of the optimum scheme increases7.19%. Results indicate that the structural optimization purposed is achieved, which is due to the static performance of the key components of wind gearbox improves efficiently with mass reduction.Through the research in this paper, the theoretical reference of lightweight design of the key parts and components of wind gearbox has been provided.