Prediction and experimental study on structure and radiation noise of subway gearbox

A dynamic finite element model of a coupled gear-rotor-bearing-housing gear system is developed by combining the gearbox transmission model with the housing structure model of subway gearbox with taking stiffness excitation, error exaction and meshing impact exaction as the dynamic excitation. The intrinsic modes and vibration response are computed in the numerical simulation process. Then an acoustic boundary element model of the gearbox is established by using the result of vibration displacement of the nodes on gearbox surface as acoustic boundary conditions. The surface sound pressure of gearbox and radiation noise of field points are solved by the direct boundary element method. In fact the proposed modeling approach not only provides a more comprehensive understanding of the subway gear system, but also can serve as the basis for dynamic and noise optimization of gear system. Finally a vibration and radiation noise experimental study is performed on the subway gear system. The vibration and radiation noise at some concerned locations are monitored and analysed. The comparison analysis shows that computational results are in good agreement with the data of experiment tests.