Analysis of Influencing Factors on the Stability of Supercritical Shaft Systems with Floating Spline Connection

To enhance the stability of supercritical tail drive systems and prevent instability caused by self-excited vibrations in floating spline-connected drive systems under supercritical operating conditions, this study thoroughly investigates the correlation mechanism between key sensitive parameters and shaft system stability. A hybrid modeling approach combining the finite element method and the lumped mass method was employed to establish a dynamic model of the supercritical shaft system with floating spline connections, and its accuracy was validated through experiments. Based on Floquet theory, the influence of factors such as tooth surface lubrication conditions, load conditions on shaft system stability, and fitting clearance of the positioning segment on shaft system stability was analyzed. The results indicate that an increase in the tooth surface friction coefficient can induce instability in the supercritical tail drive shaft system, whereas increasing torque and reducing the fitting clearance of the positioning segment significantly suppress shaft system instability.