联合收割机用柴油机曲轴模态与屈曲响应分析

Modal and buckling response analysis of engine crankshaft for combine harvester

针对联合收割机用柴油机曲轴在运行中会发生异常磨损问题,在曲轴设计时考虑振动对曲轴使用性能的影响,以及加减速对曲轴结构产生屈曲响应,利用三维软件UG建立了发动机模型,并运用NASTRAN有限元分析软件对发动机曲轴进行了模态分析和屈曲响应分析,对曲轴振动特性进行了测试。结果表明：模态分析得到曲轴前4阶模态频率为253.5～652.8Hz,有效避开了发动机工作时的激振频率;屈曲响应分析得到曲轴前10阶失稳临界载荷;曲轴振动特性测试值为联合收割机选配发动机提供了参考。

In order to solve the problem of the abnormal wear of combine harvester engine crankshaft when operating,the influences of vibration on crankshaft performance and acceleration and deceleration on buckling response to the crankshaft structure were taken into account.The parametric modeling of crankshaft was set up using the three-dimensional modeling software UG.After meshing,the modal and buckling response analysis were taken by utilizing finite element analysis software NASTRAN.In addition,the characteristic of crankshaft vibration was tested.There were 4 modal frequencies from 253.5Hz to652.8Hz at first which avoided excitation frequencies of the engine,and there were 10 buckling critical loads from buckling response analysis of the crankshaft.These test values indicate the methods have certain theoretical references for crankshaft optimal design.