Finite Element Analysis And Structural Optimization Design Of Motor-Reducer Integrated Shell

With the rapid development of society and economy,the number of cars in the world is constantly increasing,and the demand for oil is also increasing,thus causing more and more serious environmental pollution.In addition,non-renewable resources such as oil are dwindling.In this context,new energy vehicles have gained rapid development due to the advantages of energy conservation and environmental protection,and pure electric vehicles have become a research hotspot in various countries.The gearbox of pure electric vehicle is an important part of the transmission system.The gearbox plays an important role in supporting and protecting the internal gear shafting of the gearbox.The strength of the reducer casing will directly affect the transmission performance of the reducer,there should be enough strength to ensure the safety of the car driving,so it is necessary to carry out strength checking calculation of the reducer casing structure.In this paper,a pure electric vehicle motor-reducer integrated shell as the research object,because of the motor-reducer integrated shell structure is more complex,and in the process of reducer work,the shell bears more complex load,so the traditional theoretical mechanics can not be used to calculate the strength of the shell.Finite element method to calculate the strength of the shell,through the force equilibrium to solve each bearing to bear load size,shell finite element model is established and calculated by casing stress and displacement distribution of the cloud,and by looking at the maximum stress and the maximal displacement of the shell to judge whether meet the requirements of strength and stiffness.Based on the traditional single-gear reducer structure,this paper improves its structure,designs the motor-reducer integrated shell structure,and conducts static analysis and dynamic characteristic simulation analysis on the integrated shell.According to the simulation results,the structure of the integrated shell is optimized,so that the integrated shell can meet the requirements of the strength and stiffness of the shell structure while reducing the mass,and has good dynamic characteristics.The main research contents are as follows:1.The research background and significance of motor-reducer integrated shell are described in detail.Then the research status of automobile drive axle structure is introduced.2.The design principle of the integrated motor and reducer housing is introduced.According to the existing structural parameters and motor parameters of the reducer,the 3d modeling software CATIA is used to create the geometric model of the integrated motor and reducer housing.The simplified shell is imported into the Hyper Works/Hyper Mesh pre-processing module,and the finite element model of the motor-reducer integrated shell is established by dividing the grid and setting material properties of the integrated shell.3.Under the motor peak torque condition,stress analysis is carried out on each gear shaft of the reducer.Hyper Works/Opti Struct solver is applied to analyze the stiffness and strength of the finite element model of the shell.The free mode analysis and constrained mode analysis of the integrated shell are carried out respectively to solve the first ten natural frequencies,and then the meshing frequency of the input shaft of the low speed pure electric vehicle is calculated under the usual speed.The analysis results show that the integrated shell will not have resonance and has good dynamic performance.4.Based on the static analysis and modal analysis results of the motor and reducer integrated shell,the element density of the finite element model of the integrated shell was taken as the design variable,the strain energy function was taken as the optimization objective,and the volume ratio,stress and displacement were taken as constraints.The Hyper Works/Opti Struct module was used to perform topological optimization analysis on the integrated shell,and the static analysis and modal analysis were performed again on the optimized and improved integrated shell.According to the analysis results,the stiffness strength and first-order natural frequency of the optimized and improved integrated shell structure were improved to some extent.