Design and Research on Vibration Reduction of Automobile Transmission Shaft Intermediate Support 2021-01-0701

In the variable axial transmission system of an automobile, the power output of the segmented transmission shaft changes, which affects the vibration of the rear axle to a certain extent. As an important component of the drive shaft system, the intermediate support has an important effect on reducing the vibration transmission path of the drive shaft and the vibration of the rear axle system. In this paper, the vibration characteristics of the intermediate support of a certain vehicle's transmission shaft and the transmission shaft system are studied, and the vibration damping performance of the intermediate support rubber is theoretically analyzed and design optimized. In order to solve the vibration problem in the high frequency range of this car, a rubber pad was added at the position of the installation hole of the intermediate support bracket assembly to form a structure with double-layer vibration isolation effect, and the stiffness of this structure was optimized. First, the vibration transmission characteristics of the single/double-layer vibration isolation system are analyzed by the vibration isolation theory, the critical speed of the drive shaft is calculated by the finite element method, and the effective working stiffness range of the intermediate support is calculated by combining the vibration isolation theory, avoiding the resonance area. At the same time, the optimization of the stiffness of the intermediate support proposes an optimization interval. Then use virtual prototype technology to optimize the stiffness of the intermediate support and get the optimal value of stiffness. Finally, the vibration performance output of the optimized intermediate support in the whole vehicle is tested and analyzed. The results prove that the vibration isolation performance of the intermediate support with double-layer vibration isolation is consistent with the theoretical analysis conclusion.