关键词: 扭振；增程发电机；转子支架；应变能；模态贡献量

Abstract: Direct-connected range extender torque ripple of the engine is transmitted to the shaft of the coaxial generator. When the excitation frequency is coupled with the structural mode, the shaft resonance will be excited, obvious abnormal noise is heard. To address this issue, a combined finite element model of the rotor shaft and crankshaft is established using the finite element analysis method. Simulation calculate the modal and vibration mode of the shafting, and lock the problem mode in combination with the modal test; The modal contribution analysis identified a significant contribution from the rotor side. It proposes optimizing parameters such as the spoke angle, spoke thickness, and span of the rotor support bracket to achieve the optimal structure. Compared to the U-shaped structure, the T-shaped structure reduces modal strain energy by up to 50% and decreases the maximum vibration from impact by over 87% in vehicle testing. Subjective ratings improve by 1.5 points. It effectively solves the torsional vibration problem of the shafting caused by the direct connection structure of the range extender, which provides a reference for the design of the shafting structure of the direct connection range extender.

Key words: torsional vibration; range-extended generator; rotor bracket; strain energy; modal contribution