东风4型内燃机车主电路中的负载电流分配不均问题比东风型内燃机车更明显。分流不均将会造成分流大的电动机热负荷加大、绝缘老化、换向困难,严重时轮对空转,影响牵引列车。因此,必须对分流不均度超过规程的机车进行检查处理。影响分流的主要因素是电动机速率特性的偏差。而常见的因素是主磁极阻值增大。 The problem of uneven distribution of load current in the main circuit of DF4 diesel locomotive is more obvious than that of Dongfeng diesel locomotive. Unbalanced shunt will result in large shunt motor heat load increases, insulation aging, reversing difficult, serious wheel idling, affecting trains. Therefore, it is necessary to inspect and handle the locomotives whose disproportion of divergence exceeds the regulation. The main factor affecting shunting is the deviation of the motor speed characteristics. The common factor is the increase in the main pole resistance.