電(dian)(dian)(dian)機可分為直(zhi)流(liu)電(dian)(dian)(dian)機和交流(liu)電(dian)(dian)(dian)機兩種，伺服電(dian)(dian)(dian)機既有(you)直(zhi)流(liu)電(dian)(dian)(dian)機也(ye)有(you)交流(liu)電(dian)(dian)(dian)機。

1、交(jiao)流伺服電機

交流伺(si)(si)服電(dian)機(ji)內(nei)部的(de)(de)轉(zhuan)子(zi)是永(yong)磁(ci)鐵，驅動(dong)器控(kong)制的(de)(de)U/V/W三相電(dian)形成電(dian)磁(ci)場(chang)(chang)，轉(zhuan)子(zi)在此(ci)磁(ci)場(chang)(chang)的(de)(de)作用下轉(zhuan)動(dong)，同(tong)時電(dian)機(ji)自(zi)帶的(de)(de)編碼(ma)器反(fan)饋信號給驅動(dong)器，驅動(dong)器根據反(fan)饋值(zhi)(zhi)與目標值(zhi)(zhi)進(jin)行比較，調整轉(zhuan)子(zi)轉(zhuan)動(dong)的(de)(de)角度(du)。伺(si)(si)服電(dian)機(ji)的(de)(de)精度(du)決定于編碼(ma)器的(de)(de)精度(du)。

2、直流伺服電機

直流(liu)(liu)伺(si)(si)服電(dian)(dian)(dian)(dian)機(ji)(ji)包括定(ding)子(zi)、轉子(zi)鐵芯、電(dian)(dian)(dian)(dian)機(ji)(ji)轉軸、伺(si)(si)服電(dian)(dian)(dian)(dian)機(ji)(ji)繞組換向器、伺(si)(si)服電(dian)(dian)(dian)(dian)機(ji)(ji)繞組、測(ce)速(su)電(dian)(dian)(dian)(dian)機(ji)(ji)繞組、測(ce)速(su)電(dian)(dian)(dian)(dian)機(ji)(ji)換向器，轉子(zi)鐵芯由(you)矽(xi)鋼沖片(pian)疊壓固(gu)定(ding)在電(dian)(dian)(dian)(dian)機(ji)(ji)轉軸上構成。直流(liu)(liu)電(dian)(dian)(dian)(dian)機(ji)(ji)有著良好精確的速(su)度(du)控(kong)制特征，還(huan)可(ke)以(yi)在整個速(su)度(du)區(qu)內實現平滑(hua)控(kong)制，幾乎沒有任(ren)何振蕩(dang)，高效率(lv)，不(bu)發熱。

交流(liu)伺服(fu)電機和直(zhi)流(liu)伺服(fu)電機比較(jiao)起來，在功能(neng)方面交流(liu)伺服(fu)要好一些，因為是正弦(xian)波控制，轉矩脈動(dong)小，而直(zhi)流(liu)伺服(fu)是梯形(xing)波。但(dan)直(zhi)流(liu)伺服(fu)的優(you)勢就在于(yu)比較(jiao)簡單，便(bian)宜。