计入结构柔性的直升机主减速器振动特性分析

以直升机主减速器为研究对象，运用有限元/集中参数混合方法建立计入传动轴和机匣结构柔性的直升机主减速器混合动力学模型。研究了柔性机匣结构对系统振动特性的具体影响。结果表明:耦合柔性机匣结构后，各阶固有频率值降低，局部系统振幅明显改变，且使齿轮系统的共振峰幅值降低，共振转速数量减少；柔性机匣结构对动态啮合力的影响较小，而对轴承支反力的波动幅值影响显著且可分为3类,即波动幅值减小、基本不变和增大，并给出评价准则。研究结果为直升机主减速器的减振降噪与动态性能优化奠定了基础。 

Vibration characteristics analysis for helicopter main gearbox considering strutural flexibility

The helicopter main gearbox was taken as the research object, the finite-element/lumped-parameter hybrid method was used to establish a hybrid dynamic model of a helicopter main gearbox, by considering the flexibility of the shaft and housing. The specific influence of the flexible housing structure on the vibration characteristics of the main gearbox was studied. Results demonstrated that, after considering the structure of the flexible housing, the natural frequency of each order was significantly decreased, the mode shape of the system was changed obviously, and the amplitude of the resonance peak of the system was decreased and the number of resonance speed was reduced. The flexible housing structure had little influence on the dynamic meshing force, but had a greater impact on the bearing reaction force. It can be divided into three categories: the fluctuation amplitude decreases, basically remains unchanged and increases, and the judgment criteria were given. The results lay a foundation for the vibration reduction, noise reduction and dynamic performance optimization of the helicopter main gearbox.