直升机传动系统花键连接轴的动力失稳

为有效传递扭矩,花键联轴器在旋转机械中得到了广泛应用,直升机传动系统也采用了这种结构形式,因此对花键连接超临界轴的稳定性进行理论分析,并在直升机尾传动轴上开展相应的实验和验证工作.通过安装和拆卸花键两端用于润滑油脂密封的O型圈,来改变花键的工作状态,实现了尾传动轴由相对稳定向完全不稳定的转变.研究表明:由花键及其两端支承表面处产生的摩擦形成的内阻尼是导致尾传动轴发生自激振动的根源;通过改善花键连接处的工作状态,能有效改善超临界转轴的稳定性,这对直升机传动系统超临界轴的设计有一定指导意义.

Dynamic instability of helicopter transmission rotating shafts with spline coupling

To transfer torque effectively, spline coupling is widely used in rotating machinery, and it can be adopted in helicopter transmission system. Theory analysis on stability of the supercritical rotating shaft was conducted. And the corresponding experimental verification on the helicopter tail transmission shaft was developed. By installing and uninstalling O-rings on both ends of the spline, which were used to lube grease airproofing, the work state of the spline could be altered, and the conversion of the relative stability to absolute instability of helicopter tail transmission shaft could be realized. The agreement between the theoretical analysis and experimental verification indicates that the inner damping due to friction in the spline and on the supporting surface of both ends of the spline is the springhead of self-excited vibration and the stability of the supercritical shaft can be meliorated by improving the work state of spline, and they can lay the foundation of the research about the supercritical helicopter transmission shaft design.