多激励下某直升机传动系统动载特性

针对由弧齿锥齿轮和行星轮系构成的直升机传动系统,构建了纯扭振动模型,采用集中参数法建立了齿侧间隙非线性动力学方程.通过有限元方法求得了时变啮合刚度,采用4-5阶变步长Runge-Kutta法对动力学方程进行了数值求解,借助动载系数、相图、Poincaré截面图、快速傅里叶变换频谱图等分析手段,研究了传动系统在时变啮合刚度、齿侧间隙、综合传动误差、外载荷等多种激励作用下系统的动载特性.结果表明啮合刚度对传动系统的影响最大,动载系数最大值为1.5;齿侧间隙对系统响应特性的影响是有限的;啮合误差在一定程度上抑制了齿轮系统的振动;外载荷波动对不同速级的影响不同,动载系数最大值发生在并车传动.

Dynamic characteristics under various excitations for a helicopter transmission system

For a helicopter transmission system which consists of spiral bevel gears and planetary gear train, the purely torsional vibration model was established, and the non-linear dynamical equations containing backlash was built using the lumped-parameter method. Through the finite element method, the time-varying mesh stiffness was obtained, and the dynamical equations were solved by the 4-5 order Runge-Kutta algorithm with variable time step; by means of dynamic load coefficient, phase plane plots, Poincaré maps and fast Fourier transform spectra, the dynamic characteristics of transmission system were studied under various excitations of the time-varying mesh stiffness, backlash, general transmission errors and external load. The results show that mesh stiffness has the greatest effect on the transmission system, with the maximum dynamic load coefficient of 1.5; backlash has a limited effect on the response characteristics; to some extent, mesh errors can suppress the vibration of the gear system; external load fluctuation has various effects on different speed stages, and the maximum dynamic load coefficient is stemmed from the combined drive gears.