汽车四驱分动器换挡机构壳体动态特性分析与优化

Analysis and optimization of dynamic characteristics of gearshift mechanism shell for 4WD transfer box

以提高汽车四驱分动器换挡机构工作时动态特性为目的,建立该机构壳体三维简化模型,利用ANSYS软件对其进行模态分析,得到固有频率和振型,并以此为基础采用模态叠加法进行谐响应分析。通过拓扑优化,分析得到该机构壳体材料最佳分布,改进壳体结构,并与原结构进行动态特性对比分析。结果表明汽车四驱分动器换挡机构壳体固有频率增加,最大响应位移减少且低频段激振频率增加,动态特性明显改善,分析结果可为四驱汽车分动器换挡机构设计提供参考。

In order to improve the dynamic characteristics of the shift mechanism for 4WD transfer box, the simplified 3D model of the gearshift mechanism shell is established and the modal analysis is carried out by ANSYS. The natural frequen- cies and vibration modes are obtained. The mode superposition method is used to analyze harmonic response. Through the to- pology optimization, the optimum distribution of shell material is obtained to improve the shell structure, and the dynamic characteristics are compared with the original structure. The results show that with natural frequency of the gearshift mechanism shell of 4WD transfer box increase, the maximum response displacement reduces,the excited frequency increases at low frequency, and the dynamic characteristic is improved obviously. The analysis result can provide a reference for the design of the gearshift mechanism shell of 4WD transfer box.