直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)是(shi)指(zhi)能(neng)(neng)(neng)將直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)(neng)轉(zhuan)換(huan)成機(ji)(ji)(ji)(ji)械(xie)能(neng)(neng)(neng)（直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)）或將機(ji)(ji)(ji)(ji)械(xie)能(neng)(neng)(neng)轉(zhuan)換(huan)成直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)(neng)（直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)發電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)）的(de)旋轉(zhuan)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)。它是(shi)能(neng)(neng)(neng)實(shi)現直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)(neng)和機(ji)(ji)(ji)(ji)械(xie)能(neng)(neng)(neng)互相(xiang)轉(zhuan)換(huan)的(de)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)。當它作電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)運(yun)行時是(shi)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)(ji)(ji)，將電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)(neng)轉(zhuan)換(huan)為(wei)機(ji)(ji)(ji)(ji)械(xie)能(neng)(neng)(neng)；作發電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)運(yun)行時是(shi)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)發電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)，將機(ji)(ji)(ji)(ji)械(xie)能(neng)(neng)(neng)轉(zhuan)換(huan)為(wei)電(dian)(dian)(dian)(dian)(dian)能(neng)(neng)(neng)。直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)的(de)結(jie)構(gou)應由定子(zi)和轉(zhuan)子(zi)兩(liang)大(da)部(bu)分(fen)組成。直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)運(yun)行時靜止不動(dong)(dong)(dong)的(de)部(bu)分(fen)稱(cheng)為(wei)定子(zi)，定子(zi)的(de)主(zhu)要(yao)作用(yong)是(shi)產生磁(ci)場，由機(ji)(ji)(ji)(ji)座、主(zhu)磁(ci)極、換(huan)向極、端蓋、軸承和電(dian)(dian)(dian)(dian)(dian)刷裝置(zhi)等(deng)組成。直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)按照結(jie)構(gou)分(fen)為(wei)他勵(li)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)、并勵(li)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)、、串(chuan)勵(li)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)、復勵(li)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)；直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)按照使用(yong)需求通常(chang)需要(yao)搭載減(jian)速(su)齒(chi)輪箱(xiang)、行星齒(chi)輪箱(xiang)、圓柱齒(chi)輪箱(xiang)、平行齒(chi)輪箱(xiang)等(deng)，這(zhe)種產品稱(cheng)為(wei)直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)減(jian)速(su)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)；直(zhi)流(liu)(liu)(liu)(liu)(liu)(liu)(liu)減(jian)速(su)電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)廣(guang)泛應用(yong)于機(ji)(ji)(ji)(ji)械(xie)設(she)備產品、機(ji)(ji)(ji)(ji)器人、船(chuan)舶工業、通訊設(she)備、汽車(che)傳動(dong)(dong)(dong)等(deng)領(ling)域。

“交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)”是用(yong)于實現機(ji)(ji)(ji)(ji)(ji)械能(neng)和交流電(dian)(dian)(dian)(dian)能(neng)相(xiang)(xiang)互轉(zhuan)換(huan)的(de)(de)機(ji)(ji)(ji)(ji)(ji)械。由(you)于交流電(dian)(dian)(dian)(dian)力(li)系統的(de)(de)巨大(da)發(fa)(fa)展，交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)已成為最(zui)常用(yong)的(de)(de)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)。交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)與(yu)(yu)直流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)相(xiang)(xiang)比，由(you)于沒有(you)換(huan)向器（見直流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)的(de)(de)換(huan)向），因此結構簡單(dan)，制(zhi)造方(fang)便，比較牢固(gu)，容易做成高轉(zhuan)速、高電(dian)(dian)(dian)(dian)壓、大(da)電(dian)(dian)(dian)(dian)流、大(da)容量的(de)(de)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)。交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)功率的(de)(de)覆蓋范圍很大(da)，從幾瓦到幾十萬千瓦、甚至(zhi)上百萬千瓦。交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)按其功能(neng)通常分(fen)為交流發(fa)(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)、交流電(dian)(dian)(dian)(dian)動機(ji)(ji)(ji)(ji)(ji)和同步(bu)調相(xiang)(xiang)機(ji)(ji)(ji)(ji)(ji)幾大(da)類(lei)。由(you)于電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)工作(zuo)狀態的(de)(de)可逆性(xing)，同一臺電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)既(ji)可作(zuo)發(fa)(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)又可作(zuo)電(dian)(dian)(dian)(dian)動機(ji)(ji)(ji)(ji)(ji)。把電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)分(fen)為發(fa)(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)與(yu)(yu)電(dian)(dian)(dian)(dian)動機(ji)(ji)(ji)(ji)(ji)并不很確切，只(zhi)是有(you)些電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)主要作(zuo)發(fa)(fa)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)運行，有(you)些電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)主要作(zuo)電(dian)(dian)(dian)(dian)動機(ji)(ji)(ji)(ji)(ji)運行。交流電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)按品種分(fen)有(you)同步(bu)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)、異步(bu)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)兩大(da)類(lei)。同步(bu)電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)轉(zhuan)子的(de)(de)轉(zhuan)速ns與(yu)(yu)旋轉(zhuan)磁(ci)場(chang)的(de)(de)轉(zhuan)速相(xiang)(xiang)同，稱(cheng)為同步(bu)轉(zhuan)速。ns與(yu)(yu)所(suo)接交流電(dian)(dian)(dian)(dian)的(de)(de)頻率（f）、電(dian)(dian)(dian)(dian)機(ji)(ji)(ji)(ji)(ji)的(de)(de)磁(ci)極對數(shu)（P）之(zhi)間有(you)嚴格的(de)(de)關系。