从本期起,本刊将陆续发表《小型直流电机维修常识》。文中的小型直流电机系指拖拉机、内燃机的充电发电机和起动电动机,电压均为12～24伏,发电机功率为150～300瓦,起动电机功率为1.8～7马力。文章主要介绍电机的修理知识,必要时介绍一点构造、原理及与电机有关的附件等方面的知识。——编者—— From this issue, this issue will be published “Small DC motor maintenance knowledge.” In this paper, the small DC motor refers to the tractor, internal combustion engine charging generator and starter motor, voltage is 12 ~ 24 volts, the generator power of 150 ~ 300 watts, starting motor power of 1.8 to 7 horsepower. The article mainly introduces the repair knowledge of the motor, if necessary, introduce a little structure, principle and motor-related accessories and other aspects of knowledge. --editor--