关键词: 驱动桥；噪声优化；齿轮；下推力杆

Abstract: A series of vehicle tests are conducted to address the issue of poor noise, vibration, harshness (NVH) performance of the 9.5-ton drive axle assembly of a certain passenger car. The root causes of the problem are ultimately determined, including insufficient isolation rate of the lower thrust rod and design and manufacturing errors in the main reducer gear. In order to reduce the noise of the drive axle assembly, improvements and optimizations have been made, including tooth surface modification of the hypoid gear of the main reducer and design improvements of the lower thrust rod structure. In order to verify the rationality of the two optimization schemes, bench tests are conducted in the laboratory and whole vehicle tests are conducted in actual driving environments. The effects of gear modification of the main reducer and optimization of the lower thrust rod structure on the noise of the drive axle assembly are analyzed. The results show that both optimization schemes reduce the noise of the drive axle assembly by about 10 dB(A), with a significant reduction in the noise values of the 9th order and its harmonics. Therefore, both optimization schemes have played a certain role in vibration reduction and noise reduction, providing a reference for improving the NVH performance of the bus drive axle assembly.

Key words: Drive axle; Optimization of noise; Gear; Lower thrust rod