Structural Design And Optimization Of 2AT Automatic Transmission For Pure Electric Vehicle

In recent years,with the problem of environmental pollution and energy crisis draw more and more attention,the development of new energy has become the mainstream direction of the development of various countries,the electric cars as a mainstream transport have great potential and development prospects in the future.As the core component of electric vehicle power transmission system,the performance of the gearbox is very important to dynamic property and economy of the vehicle.Therefore,the design and research of electric vehicle gearbox are of great significance to the development of electric vehicles.In this paper,a pure electric vehicle from a car company studies the design of its two-speed automatic transmission and lightweight in this paper.In this paper,the major research work are as follows:(1)According to the specific requirements and design principles of two speed automatic gearbox,combined with the basic requirements of the electric vehicle performance index,the main drive system parameters such as motor parameters,main reducer parameters are regarded as a comprehensive matching.(2)According to the specific parameters of the structure and the design principle of transmission,the specific structure of the transmission was designed in detail,including the double planetary gear reducer design,main decelerator overall design,bearing selection and shell partial design.(3)The finite element analysis of the structure with large load on the gearbox is carried out,including static strength analysis of finite element of planetary frame,to analyze whether the structure strength is qualified;including finite element analysis of the gear ring,to analyze whether the maximum deformation of the ring gear meet the design requirements of the bearing;including static strength analysis of the maximum contact stress,to analyze whether the position of maximum contact stress is accurate and the maximum value of contact stress is in the range of values;including the static stress analysis and dynamic modal analysis,getting the size and location of the maximum stress in order to provide the basis for further optimization design.(4)Considering the displacement,stress,first order natural frequency and volume ratio as the constraint,the combined static topology optimization of the shell is carried out with the combination of strain energy index as the objective.Then based on the optimization results and considering the manufacturing process and installation requirements,improve the design of structure in detail.(5)The improved gearbox test prototype is taken as the research object,no-load power loss test,high-speed loading reliability test and gearbox vibration test are carried out.The results show that the optimized improved gearbox meets basic performance requirements,the structural strength and the first order natural frequency are effectively improved,and the quality of the gearbox casing is reduced from 8.238 kg to 7.529 kg,which is reduced by 8.6%,and the purpose of lightweight is achieved.