A new method for analyzing gearbox vibration and noise in electric drive systems based on different modal forms

To enhance the accuracy of vibration and noise predictions for gear reducers in electric drive systems, this paper proposes a novel method for analyzing the vibration and noise of gear systems based on different modal forms. Initially, the paper compares the modal information of the housing with the shaft system (HWSS) model with that of the traditional single housing (SH) model for the first 20 modes. Subsequently, a dynamic model is constructed that accounts for factors such as shaft flexibility, gear flexibility, bearing stiffness, and gyroscopic effects. Utilizing the modal superposition method and the boundary element method (BEM), dynamic load excitations are introduced at the bearing locations of both modes (SH and HWSS modes) to derive the vibration response and noise. The results are then compared with measurements obtained from the vehicle test. The findings indicate that both models effectively reflect the meshing vibrations generated during gear engagement. However, the vibration amplitudes of the HWSS model are consistently smaller than those of the SH model, aligning more closely with the test. Finally, by contrasting the effective sound pressure levels (ESPL) of both models across the entire speed range, it is shown that the HWSS model better represents actual noise conditions at points farther from the sound source. This research provides an innovative approach for accurately predicting the vibration response and noise of gearboxes.