ZD109C直流牽引電動機，是種用于大功率貨運內燃機車的四極強迫通風串勵直流牽引電動機。其結構特點是：機座采用抱軸瓦焊接機座，滑動抱軸承結構；換向器端軸頭裝有測速齒盤，換向器軸承蓋留有軸承溫度傳感器安裝口。同時，換向器端傳動端軸承蓋上留有軸承溫度傳感器安裝孔。電樞繞組采用薄膜導線，NOMEX紙槽形絕緣結構；主附極線圈采用壓型的一體化結構；工藝上，定轉子采用真空壓力浸漆處理。該電機主要用于東風8B內燃機上。

　　ZD109C D .C. Traction motor is one type of high-power passenger and freight diesel locomotives D.C motor which is four poles, forced ventilation and series wound. Frame is a press-formed welded fabrication and hugging bearing or bush structure; Speed gear plate is mounted on shaft end of commutator. There is a hole for mounting bearing temperature sensors on commutator bearing cover and another hole on driving end bearing cover. The insulation film leading wire and Nomex slot insulation paper is used for armature winding. Main pole coil and commutating pole coil are press-formed unit-body construction. Impregnation of stator and rotor is VPI. This type motor is mainly used in Dongfeng 8B diesel locomotive.

　　主要技術參數：

　　● 額定功率（Rated Power）：530KW

　　● 額定電壓（Rated Voltage）: 670V

　　● 額定電流（Rated Current）: 845A

　　● 額定轉速（Rated Speed）: 770r/min

　　● 最大轉速（Max Speed）: 2385 r/min

　　● 額定效率（Rated Efficiency）: 93%

　　● 最高電壓（Max Voltage）: 980V

　　● 最大恒功率轉速（Max Speed at Constant Power）: 2190 r/min

　　● 最大電流（Max Current）: 1200A

　　● 工作制（Duty）: s1

　　● 絕緣等級（Insulation class ）: H/H

　　● 勵磁方式（Exciting Type）: 串勵 Serier-Wound

　　● 冷卻方式（Cooling Method）: 強迫通風 Forced Ventilation

　　● 重    量（Weight）: 3007kg