汽车电动助力转向电机过热失效问题分析及优化

Analysis of Motor Overheat Failure for Automobile Electric Power Steering System

介绍了汽车电动助力转向系统(EPS)电机过热对转向系统性能的影响,分析了造成电机过热的各种因素,根据各不同因素提出相应整改方案,并通过对比试验进行效果验证.主要基于某款车型在市场上出现的EPS电机过热烧蚀的问题,利用EPS调试系统监控控制器以及电机最高工作电流,发现控制器及电机最高工作电流超出最高设计值;通过将热电偶埋入电机碳刷内部跟踪测量电机工作温度峰值,发现电机内部温度高于碳刷架耐受温度.同时对比测量电机碳刷架材料耐热温度,发现本电机碳刷架耐热温度远低于行业内部分品牌电机,最后通过试验证实了以上多种导致电机过热烧蚀的原因,并逐一制定改进措施,最终解决电机过热烧蚀问题,验证效果良好.

The influence of the motor overheat from the electric power steering system （EPS） is introduced on the performance of the system. The causes of the overheating are analyzed, the corresponding measurements are put forward and the effect of the rectification is verified by the contrast tests. Based on the ablation problem from the motor overheating in its EPS of a car, the highest operating current of both the controller and the motor is found to exceed the maximum design limit by means of the EPS debugging system. In order to measure the peak value of its working temperature, a thermocouple is embedded in the carbon brush of the motor, and the internal temperature of the motor is found to be higher than the tolerance temperature of the brush rack. The heat-resistance temperature of the rack in this motor is much lower than that of the motors with other brands. The reasons for the motor overheating are confirmed by some experiments, the improvement measures are made one by one, and the problems of both the overheating and the ablation are solved eventually.