基于实际行驶载荷的电动汽车差速器扭转疲劳试验方法研究

电动汽车电机具有高频转矩特性,其冲击载荷对减速器、差速器等传动系统疲劳寿命的影响越来越受到企业的重视。根据电动汽车差速器实际受扭转载荷情况,设计了基于液压伺服的电动汽车差速器扭转疲劳试验系统。采用无线遥测系统在垫江试验场按照帕斯卡试验规范对电动汽车半轴转矩进行了实车采集,通过对采集的半轴转矩载荷谱进行预处理和时频域特征分析后,确定了扭转疲劳试验加载波形为正弦波,加载频率为0.5 Hz。通过雨流计数和外推确定了加载幅值和加载频次,从而建立了电动汽车差速器扭转疲劳试验方法。最后,搭建电动汽车差速器扭转疲劳试验系统,对该试验方法进行了验证。结果表明,差速器的疲劳破坏部位及形式与实车行驶时疲劳破坏部位及形式一致,所建立的方法是有效可行的。

Research on Torsional Fatigue Test Method of Electric Vehicle Differential based on Actual Driving Load

Due to the high-frequency torque characteristics of electric vehicle motors,the impact load of their effect on the fatigue life of transmission systems such as reducers and differentials has been paid more and more attention by enterprises.According to the actual torsion load of electric vehicle differential,a torsion fatigue test system of electric vehicle differential based on hydraulic servo is designed.A wireless telemetry system is used to collect the axle shaft torque of electric vehicle in Dianjiang test site according to Pascal test specification.After preprocessing the collected axle shaft torque load spectrum and analyzing the characteristics in time-frequency domain,it is determined that the load waveform of torsional fatigue test is sine wave and the load frequency is 0.5 Hz.Through rainflow counting and extrapolation,the loading amplitude and frequency are determined,thus a torsional fatigue test method for differential of electric vehicles is established.Finally,an electric vehicle differential torsion fatigue test system is set up to verify the test method.The results show that the fatigue failure parts and forms of the differential are consistent with those of the real vehicle,and the established method is effective and feasible.