Nonlinear torsional vibrations of electromechanical coupling of diesel engine gear system and electric generator

Abstract New approach for analysis and detuning of nonlinear torsional vibrations of diesel electric generator gear system is suggested. Nonlinear magnetic field of the generator is calculated by finite element method to obtain the disturbing moments, which act on the gear system. Moreover, others disturbing moments, which arise due to operation in diesel engine cylinders, are accounted. Essential nonlinear model of torsional vibrations with sixteen degrees-of- freedom is derived. This model accounts the nonlinear moments of two elastic clutches and the backlashes of gear pairs. The comparison of the numerical simulations data with experimental results is performed to verify the obtained model. The approach for essential nonlinear free torsional vibrations calculations is suggested. The harmonic balanced method is the basis of this approach. Sensitivity theory is used to detune the nonlinear forced torsional vibrations from resonances. The results of nonlinear torsional vibrations analysis are discussed.