The Dynamic Load of Inter-Shaft Bearing and its Transmission Characteristic of Complex Rotor System

Abstract

Aiming at the dynamic design of dual rotor of aero-engine, the dynamic model of dual rotor system was established. And then based on the simulation results of the dynamic model established above, the unbalance distribution of dual rotor and the strain energy distribution of the flexural deformation were analyzed. The results showed that the dynamic load on inter-shaft bearing is determined by the rotor vibration mode and the rotor vibration response at the position of bearing. The flexural deformation can also affect the dynamic load on inter-shaft bearing. Under the influence of elastic restoring force generated by the flexural deformation of rotors, the dynamic load on the inter-shaft bearing under flexural mode is higher than that under the rigid mode. It was found that large dynamic load may act on inter-shaft bearing even though the rotor is not operating in the resonance state. And due to the internal damping of the rotor, the large dynamic load on the inter-shaft bearing can be obviously reduced when the load transmit to other bearings via the rotor with flexural deformation.