Abstract: Taking the differential of an electric vehicle as the research object, a method for analyzing and predicting the fatigue life of the differential of the electric drive assembly based on the vehicle test load spectrum is proposed. The vehicle dynamics model of the target vehicle and the road topology model of the test site are established. The durable load spectrum of the electric drive assembly is iteratively generated through dynamic analysis, and then converted into the test load spectrum of the differential. The finite element model of the differential assembly is built. According to the load spectrum of the differential bench test, the stress change process of the differential in the process of variable torque and variable speed meshing is obtained, which dynamically reflects the real stress state of the differential at work. The alternating fatigue damage caused by the rapid alternating torque and speed of the differential is fully considered. The results show that the fatigue failure position of the differential shell is consistent with the fatigue failure position during the test, which provides a comprehensive and accurate reference for the design and verification of the differential structure.

Key words: Differential of electric drive assembly; Alternating load; Dynamic meshing; Fatigue life

摘要： 以某电动汽车差速器为研究对象，提出了基于整车试验载荷谱对电驱动总成差速器疲 劳寿命分析预测的方法。建立目标车型的整车动力学模型及试验场地道路拓扑模型，通过动 力学分析迭代生成电驱动总成耐久载荷谱，进而转化为差速器的试验载荷谱。搭建差速器总 成有限元模型，根据差速器台架试验载荷谱以得到差速器在变转矩变转速啮合过程中的应力 变化历程，动态反应了差速器在工作时的真实受力状态，充分考虑差速器在转矩及转速快速 交变而冲击造成的交变疲劳损伤情况。结果表明，差速器壳体疲劳失效位置与试验时疲劳失 效位置一致，进而为差速器结构的设计及校验提供全面且精确的参考。

关键词: 电驱动总成差速器；交变载荷；动态啮合；疲劳寿命