Structural Topology Optimization And Mechanical Analysis Of Two-speed Planetary Gear System

In a two-stage gearbox with planetary gear train,the planetary gear train is the key component to transmit power,bear load and change transmission ratio.The planetary gear train has the advantages of large carrying capacity,small structure size and being able to guarantee coaxial input and output,therefore,the lightweight design and dynamic performance evaluation of planetary gear trains have a direct impact on the improvement of gearbox performance.In this paper,the planetary gear train with two gears is taken as the research object,the structural parameters are designed and topology optimization is carried out to reduce the mass,and the structural strength is simulated and verified,then,the natural characteristic analysis,modal experiment and modal simulation are carried out to evaluate the optimized structure dynamic characteristic.The main contents of this paper are as follows:(1)The three variable speed transmission configurations were evaluated by evaluation indexes,Based on the theoretical calculation model of concentricity requirement,adjacency requirement,installation requirement,transmission ratio requirement and strength check formula for planetary gear train,the calculation and analysis software of planetary gear train is compiled,the matching parameters of planetary gear train are calculated,and the 3D model of double planetary gear train is built in Ug.(2)The location of the intensity redundancy is taken as the optimization area,the topology optimization is simulated by the finite element method,and then the optimized model is imported into the 3D modeling software to reconstruct the MODEL,the strength of the reconstructed model is verified by the finite element software ABAQUS,and the lightweight design of the part is completed,the mass of the planetary gear is reduced by 19.1%,the mass of the planetary frame on the output side is reduced by 44.8%,the mass of the first inner ring gear is reduced by 6.3%,and the mass of the second inner ring gear is reduced by7.9%.(3)A multi-degree-of-freedom dynamic model of translation-torsion coupling for double planetary gear trains is established by using the concentrated mass method,the excitation frequency of the planetary gear system is calculated,the effects of Mesh stiffness,support stiffness and mass change on the inherent characteristics of high and low speed gears are analyzed and discussed.The results show that the system support stiffness mainly affects the low-order natural characteristics of the two gears,and the meshing stiffness mainly affects the high-order natural characteristics of the two gears.The quality of planetary gear affects the inherent characteristics of each stage of two stages,the quality of planetary frame has more obvious influence on the inherent characteristics of the intermediate stage of two stages,and the quality of other parts has more obvious influence on the inherent characteristics of the upper and lower stages of two stages.(4)The free mode experiment of the optimized solar gear is carried out.The free mode simulation of the optimized parts is carried out.The results of the modal experiment and the modal simulation of the solar gear are similar,there is an interval of more than 1.5 ～ 2 times between the loworder natural frequency and the excitation frequency of the solar gear,and there is an interval of more than 2 times between the simulated low-order modal frequency and the low-order excitation frequency of the other parts,it has good dynamic performance.