Differential Assembly Friction Induced Noise Diagnosis Analysis and Engineering Solution for the Electric Vehicle Steering Operation at Low Speed Cruise 2022-01-0646

With the improvement of vehicle comfort requirements of market users, NVH performance has been paid more and more attention. Especially the pure electric passenger vehicle is lack of combustion engine noise masking effect, it is more likely to cause the drivers attention for any abnormal noise. In the steering operation under the low speed acceleration of pure electric vehicles, the cabin interior noise derived from the road and the wind is relatively low, and there is not marketing effect of traditional internal combustion engine noise, any slight abnormal noise is more likely for the drivers and passengers feel unsafe and complain. However, there is lack of systematic analysis and research on the untypical NVH problem in the automotive industry.

This paper systematically expounds the test and analysis process of abnormal noise. According to the correlation comparison between the full vehicle and the drivetrain subsystem platform, it is found that the differential assembly is the source of abnormal noise. At the same time, combined with the tribology theory and interface mechanics, this paper discusses the potential mechanism of the abnormal noise problem, and provides the specific engineering countermeasure. In addition, in this paper, the electric vehicle steering abnormal noise is completely eliminated by using the manganese phosphate coating process on the axle gear gasket. This paper has guiding significance and engineering reference to the NVH performance development for pure electric vehicle differential assembly.