电动汽车变速箱壳体静动态分析及拓扑优化设计

Static and Dynamic Analysis and Topological Optimization of Gearbox Housing in Electric Vehicle

以一种新型的电动汽车无动力中断两挡变速箱为研究对象,为了提高其稳定性和经济性,对其壳体进行设计与优化。首先,进行了壳体结构设计并建立其有限元模型。在此基础上,对壳体进行刚度强度计算和更加符合工程实际的约束模态计算,并通过约束模态试验验证了有限元模型的准确性。仿真及试验结果表明,壳体刚度偏低且前两阶固有频率与常用转速下齿轮啮合激励频率非常接近。根据静动态多目标拓扑优化结果指导壳体进行结构改进,改进后的壳体计算结果表明,强度基本不变,轴承孔区域最大位移由0.085 mm减小至0.07 mm,前两阶固有频率分别提高了24.8 Hz和50.2 Hz,降低了发生共振的风险,且质量减少了7.5%。

Taking a new type of two speed transmission without power interruption in electric vehicles as research object,in order to improve its stability and economy,the housing is designed and optimized.Firstly,the housing structure is designed and its finite element model is established.On this basis,the stiffness and strength of the housing are calculated and the constrained modal calculation is more in line with the engineering practice.The accuracy of the finite element model is verified by the constrained modal test.The simulation and test results show that the stiffness of the housing is low,and the first two natural frequencies are very close to the excitation frequency of gear meshing at the common speed.According to the results of static and dynamic multi-objective topology optimization,the housing structure is improved.The calculation results of the improved housing show that the strength is basically unchanged,the maximum displacement of the bearing hole area is reduced from 0.085 mm to 0.07 mm,the natural frequencies of the first two orders are increased by 24.8 Hz and 50.2 Hz respectively,which reduces the risk of resonance and reduces the mass by 7.5%.