STUDY ON PATTERN CHARACTERISTICS OF MULTI STABLE REGIONS OF HYDRODYNAMIC BEARING-ROTOR SYSTEM

A study on the threshold and regional pattern of stability for a hydrodynamic bearing rotor system equipped with external elastic damping support is conducted, which is based on linear assumption. First, the analytical expressions of the threshold speed and whirling frequency of rotor for the vertical system are obtained. Then the numerical calculation on the regional pattern of the horizontal system is carried out. The results show that multi stable regions may appear in hydrodynamic bearing rotor system equipped with external elastic damping support. For the vertical system, there are at most three threshold speeds that form a pattern of two stable regions and two unstable ones. On the other hand, there are at most four threshold speeds for the horizontal system, which evolve a pattern of three stable regions and two unstable ones.