A rigid rotor system which is driven through a Universal joint (U-joint) and is mounted on weakly-damped flexible supports exhibits principal and combination type parametric instabilities at certain torque-speed combinations. In this article, the transient dynamics of such a non-linear system driven by a non-ideal source (a DC motor) is studied through numerical simulation of the bond graph model of the system. It is shown that the dynamic coupling between the DC motor and the whirling rotor in the non-ideal system can stabilize the system in the speed ranges where the corresponding ideal system is unstable. This stabilization depends upon the motor characteristic constant or the torque/speed constant; i.e. if two motors with different motor characteristic constants produce the same torque at the same operating speed (where the ideal system is unstable) then the motor with higher motor characteristic constant tends to better stabilize the system. This bounded-input bounded-output stabilization is shown to occur through repeated transitions between stable and unstable speed regions. Several simulation results for the system driven by ideal and non-ideal sources at different operating speeds are presented to derive motor sizing specifications.

通过万向节（U型接头）驱动并安装在阻尼较弱的柔性支架上的刚性转子系统在某些转矩-速度组合下表现出主要和组合类型的参数不稳定性。在本文中，通过对系统的键合图模型进行数值模拟，研究了由非理想电源（直流电动机）驱动的这种非线性系统的瞬态动力学。结果表明，非理想系统中直流电动机和回旋转子之间的动态耦合可以使系统稳定在相应理想系统不稳定的速度范围内。这种稳定取决于电动机的特性常数或转矩/速度常数。IE 如果两个具有不同电动机特性常数的电动机在相同的运行速度下（理想系统不稳定的情况下）产生相同的转矩，则具有较高电动机特性常数的电动机往往会更好地稳定系统。已证明这种有界输入有界输出稳定化是通过稳定和不稳定速度区域之间的重复过渡发生的。给出了在不同工作速度下由理想和非理想源驱动的系统的几个仿真结果，以得出电动机的尺寸规格。