中文摘要：

对直升机尾传动系统进行了简化,提出了直升机的尾传动系统是由多个轴段和圆盘组成的串联系统;建立了直升机尾传动系统的弯曲振动力学模型,模型中考虑了轴承支承刚度、联轴器的角向刚度及径向刚度;根据系统的弯曲振动力学方程,用传递矩阵法求得了系统的固有频率.结果表明：联轴器的角向刚度与径向刚度对系统的固有频率有不同的影响;增加轴段数或轴承的刚度可以降低系统的固有频率.

英文摘要：

The helicopter tail drive system was simplified, and it was presented that a helicopter tail drive system was a cascade system comprising shaft segments and disks. A bending dynamic analysis model in which the support stiffness of the bearing and coupling were included was established. Using transfer matrix method, the differential equations were solved. The results show that the effect of the angular stiffness and the radial stiffness of coupling on natural frequencies of the helicopter tail drive system is different, and the natural frequencies could be reduced with the increase of shaft segments or stiffness of the bearing.