Dynamic modelling and vibration analysis of dual-rotor system with inter-shaft sprag clutch and bearings

In this paper, a new analytical model is developed for dual-rotor system with inter-shaft sprag clutch and bearings, which consists of the inner shaft, the outer shaft, the inter-shaft sprag clutch and bearings. First, the inner and outer shafts are modeled as six degrees freedom Timoshenko's beams including the centrifugal force and gyroscopic effects. Then, the sprag clutch with profile modification is firstly modeled as a torsional finite element based on its load-deflection relationship, and the inter-shaft bearings are modeled as standard nonlinear finite elements including the centrifugal force and gyroscopic moments of the rolling elements of bearings. In subsequent analysis, the natural frequency and mode shape of the system are analyzed and verified. The new model will be useful to investigate the coupled vibration of bending and torsion and contribute to the dynamic design of rotor system with inter-shaft sprag clutch and bearings.