Nonlinear Dynamic Stability of Labyrinth Seal-Sliding Bearing-Rotor System

The nonlinear dynamic stability of labyrinth seal-sliding bearing-unbalanced rotor systems is studied in this paper. Under the periodic excitation of rotor unbalance, the whirling vibration of a rotor is synchronous if the rotation speed is below the stability threshold, whereas the vibration becomes severe and asynchronous which is called unstable if the rotation speed exceeds the threshold. The Muszynska model of the seal force, short bearing and shooting method are used to investigate synchsonous solution of the dynamic equation of the rotor system, and then based on Floquet theory the stability of synchronous solution and unstable dynamic behaviors of the system are analyzed.