ANALYSIS OF THE COUPLED LATERAL TORSIONAL VIBRATION OF A ROTOR-BEARING SYSTEM WITH A MISALIGNED GEAR COUPLING

The misalignment of a gear coupling in a multirotor system is an important problem; it can cause various faults. In the present work the non-linear coupled lateral torsional vibration model of rotor-bearing-gear coupling system is developed based on the engagement conditions of gear couplings. Theoretical analysis shows that the forces and moments acting on gear couplings due to the initial misalignment are from the inertia forces of the sleeve and the internal damping between the meshing teeth, and depend on the misalignment, internal damping, the rotating speed, and the structural parameters of the gear coupling. Numerical analysis of the signature of vibration reveals that the even-integer multiples of the rotating speed of lateral vibration and the odd-integer multiples of the torsional vibration occur in the misaligned system, and the integer multiples of vibration are apparent around the gear coupling.