《环火》通常是指在电机两相反极性碳刷间的换向器表面上或某个刷握与机体之间出现强大电弧。大功率电机多半容易产生这种现象,具有严格界限及重量限制的牵引电动机(功率达3000千瓦)便属于这类。很宽的转速调节范围,几乎不断改变的工作状态,非常大的动力作用,急剧的温度变化,潮湿、肮脏的环境,所有这一切都加重了牵引电动机的工作条件,以致可将牵引电动机列入最紧张的直流电机范围之内。还值得指出的是电力机车车辆 “Ring Fire” usually means that a strong arc occurs between the commutator between two opposite polarity carbon brushes or between one brush holder and the body. High-power motors are prone to this phenomenon, with strict limits and weight restrictions traction motor (power up to 3000 kilowatts) will fall into this category. Very wide speed adjustment range, almost constantly changing working conditions, very large power, rapid temperature changes, wet, dirty environment, all of this aggravates the working conditions of the traction motor, so that the traction motor column Into the most intense range of DC motor. It is also worth pointing out that electric locomotive vehicles