基于完全析因实验的后桥异响故障诊断分析

Fault Analysis of Abnormal Noise of Rear Drive Axle Based on Complete Factorial Experiment

针对某车型后驱动桥存在全工况异响问题。通过噪声测试,发现异响与齿轮阶次无关,是传动轴阶次噪声所为;应用完全析因实验分析、相关分析、贡献度分析,确认异响是传动轴、凸缘、主减3个因素共同作用导致的扭振系统问题;通过拆解分析,故障根源被锁定为主减轴承预紧力不足、传动轴不平衡量过大、凸缘止口跳动超差。最终通过工艺优化,提出了一种全新的基于完全析因实验的故障分析方法。结果表明:传动轴阶次噪声降低10 dB(A),彻底解决了异响问题,后期产品未再出现该问题。

The rear drive axle of a certain vehicle has abnormal sound in all kinds of working condition.Through noise test,it is found that the abnormal noise has nothing to do with the order of gear,but is the order noise of drive shaft.By means of complete factorial experiments,correlation analysis and contribution analysis,the abnormal sound is confirmed to be the torsional vibration system problem caused by the joint action of three factors,namely,the drive shaft,flange and final drive.Through the disassembly analysis,the fault source is locked,mainly reducing the bearing preload is insufficient,the transmission shaft unbalance is too large,flange runout of tolerance.Finally,through process optimization,a new fault analysis method based on complete factorial experiments was provided.The result shows that the order noise of the transmission shaft is reduced by 10 dB(A),and the abnormal sound problem is completely solved.The problem did not appear in the later products.