An Optimization Study of Dynamic Stiffness for Transmission Support Brackets

Transmission support bracket is an important component in aspect of vibration and noise of vehicle transfer system. But shape and length of bracket are often determined passively according to fixed powertrain layout and mounting point on the vehicle development process. In General, main excitation sources of transmission are planetary gear and oil pump. In case of FF type transmission, the 1st mode of bracket mostly exists in frequency range of 300Hz~800Hz. This frequency range is overlapped with the excitation range(under 600Hz) of plenatary gear and oil pump. Therefore, bracket 1st mode amplifies excitation order of plenatary gear and oil pump, and resonance occurs. As a result, bracket vibration is transferred to vehicle chassis system, where structure-borne cabin noise level is poor in severe cases. This study produces optimized bracket that is satisfied with dynamic stiffness standard and lightweight using Radioss and Optistruct. In the near future, vibration and noise test results of optimized bracket will be correlated with analysis results. This optimization process provides bracket design guide in the initial stage of transmission development, and reduction of cost and weight.

 

The Author

Mr. SIWOO LEE
Research Engineer
HYUNDAI MOTOR COMPANY