Vibration Characteristics of Two Rotors Connected by Rigid Coupling With Parallel Misalignment

The dynamical equation of parallel misalignment rotor-bearing systems is derived,using Lagrangian dynamics.The effect of the rigid coupling parallel misalignment and the rotor unbalance is examined with theoretical and numerical analysis.At steady state condition,the 1X-rotational speed excitation is present in the lateral vibration direction,which indicates that parallel misalignment of the rigid coupling can be a source of lateral excitation.The axial locus of the rotor systems is a steady circle after full decay.Simulation results showed the amplitude of the driving shaft might be bigger than the driven shaft's.The effect of the transient response on the parallel misalignment to the rotor-bearing systems with less bearing stiffness is stronger.