The coupled dynamic model of the intermediate and tail gearboxes’ spiral bevel gear-oblique tail shaft-laminated membrane coupling was established by employing the hybrid modeling method of finite element and lumped mass. Among them, the dynamic equation of the shaft was constructed by Timoshenko beam; spiral bevel gears were derived theoretically by the lumped-mass method, where the effects of time-varying meshing stiffness, transmission error, external imbalance excitation and the like were considered simultaneously; laminated membrane coupling was simplified to a lumped parameter model, in which the stiffness was obtained by the finite element simulation and experiment. On this basis, the laminated membrane coupling and effects of several important parameters, including the unbalance value, tail rotor excitation, oblique tail shaft’s length and transmission error amplitude, on the system’s dynamic characteristics were discussed. The results showed that the influences of laminated membrane coupling and transmission error amplitude on the coupled system’s vibration response were prominent, which should be taken into consideration in the dynamic model. Due to the bending-torsional coupled effect, the lateral vibration caused by gear eccentricity would enlarge the oblique tail shaft’s torsional vibration; similarly, the tail rotor’s torsional excitation also varies the lateral vibration of the oblique tail shaft. The coupled effect between the eccentricity of gear pairs mainly hit the torsional vibration. Also, as the oblique tail shaft’s length increased, the torsional vibration of the oblique tail shaft tended to diminish while the axis orbit became larger. The research provides theoretical support for the design of the helicopter tail transmission system.

采用有限元与集总质量的混合建模方法，建立了中，后齿轮箱螺旋锥齿轮-斜尾轴-叠片膜片耦合动力学模型。其中，轴的动力学方程是由季莫申科梁建立的。从理论上通过集中质量法推导了螺旋锥齿轮，同时考虑了时变啮合刚度，传动误差，外部不平衡励磁等的影响。叠层膜耦合简化为集总参数模型，通过有限元模拟和实验获得刚度。在此基础上，叠层膜的耦合和几个重要参数的影响，包括不平衡值，尾转子的励磁，斜尾轴的长度和传动​​误差幅度，对系统的动力学特性进行了讨论。结果表明，叠层膜耦合和传输误差幅度对耦合系统振动响应的影响是显着的，在动力学模型中应予以考虑。由于弯扭耦合作用，齿轮偏心引起的侧向振动会增大斜尾轴的扭转振动。同样，尾桨的扭转激励也会改变斜尾轴的横向振动。齿轮副的偏心率之间的耦合作用主要影响扭转振动。而且，随着斜尾轴的长度增加，当轴轨道变大时，斜尾轴的扭转振动趋于减小。