機(ji)(ji)器(qi)(qi)(qi)人(ren)(ren)電(dian)機(ji)(ji)驅(qu)動(dong)器(qi)(qi)(qi)用來使機(ji)(ji)器(qi)(qi)(qi)人(ren)(ren)發(fa)出動(dong)作的動(dong)力機(ji)(ji)構(gou)。機(ji)(ji)器(qi)(qi)(qi)人(ren)(ren)驅(qu)動(dong)器(qi)(qi)(qi)可將(jiang)電(dian)能(neng)、液壓(ya)能(neng)和氣壓(ya)能(neng)轉化為機(ji)(ji)器(qi)(qi)(qi)人(ren)(ren)的動(dong)力。包括直流伺服電(dian)機(ji)(ji)、步進(jin)電(dian)機(ji)(ji)和交流伺服電(dian)機(ji)(ji);常用的機(ji)(ji)器(qi)(qi)(qi)人(ren)(ren)電(dian)機(ji)(ji)驅(qu)動(dong)器(qi)(qi)(qi)有如下幾種:
1.直流(liu)伺服電動(dong)機驅動(dong)器
直流驅(qu)動器多采(cai)用脈(mo)寬調制(zhi)(PWM)伺服驅動(dong)器,通過改變脈沖寬度來改變加在(zai)電(dian)(dian)動(dong)機電(dian)(dian)樞兩(liang)端的(de)平均(jun)電(dian)(dian)壓,從而改變電(dian)(dian)動(dong)機的(de)轉速。PWM伺服驅動(dong)器(qi)(qi)具有調速范圍(wei)寬、低速特(te)性好、響應(ying)快、效(xiao)率(lv)高、過載能力(li)強等特(te)點,在工業機器(qi)(qi)人(ren)中常作為直流伺服電(dian)動(dong)機驅動(dong)器(qi)(qi)。
2.同步式交(jiao)流伺(si)服電動機(ji)驅動器
同(tong)直流伺服(fu)電(dian)(dian)動(dong)(dong)機驅動(dong)(dong)系統相比(bi),同(tong)步式(shi)交流伺服(fu)電(dian)(dian)動(dong)(dong)機驅動(dong)(dong)器具(ju)有轉矩轉動(dong)(dong)慣量比(bi)高、無電(dian)(dian)刷及換向火花等優點(dian),在工業機器人中得(de)到(dao)廣泛應用。同(tong)步式(shi)交流伺服(fu)電(dian)(dian)動(dong)(dong)機驅動(dong)(dong)器通(tong)常采用電(dian)(dian)流型脈寬調制(zhi)(PWM)相(xiang)逆變器和(he)具有電流(liu)環(huan)(huan)為內(nei)環(huan)(huan)、速度環(huan)(huan)為外環(huan)(huan)的多閉環(huan)(huan)控制(zhi)(zhi)系統,以(yi)實現對三(san)相(xiang)永磁同步伺(si)服電動機的電流(liu)控制(zhi)(zhi)。根據(ju)其工作原(yuan)理、驅動電流(liu)波形和(he)控制(zhi)(zhi)方式的不(bu)同,它又可分為兩種伺(si)服系統:
a.矩形(xing)波電流驅動的永磁交(jiao)流伺服系(xi)統。
b.正弦波電(dian)流驅動的永磁交流伺服系統。
采用矩形波(bo)電流(liu)驅動(dong)的(de)永磁交流(liu)伺(si)服(fu)電動(dong)機稱為無(wu)刷(shua)直流(liu)伺(si)服(fu)電動(dong)機,采用正弦波(bo)電流(liu)驅動(dong)的(de)永磁交流(liu)伺(si)服(fu)電動(dong)機稱為無(wu)刷(shua)交流(liu)伺(si)服(fu)電動(dong)機。
3.步進電動(dong)機(ji)驅(qu)動(dong)器
步進(jin)(jin)電動(dong)機是將電脈(mo)沖信號變換(huan)為相應的(de)(de)角位(wei)移或直線(xian)位(wei)移的(de)(de)元件(jian),它的(de)(de)角位(wei)移和線(xian)位(wei)移量與(yu)脈(mo)沖數成正比。轉(zhuan)速(su)(su)或線(xian)速(su)(su)度與(yu)脈(mo)沖頻率成正比。在(zai)負(fu)載能力的(de)(de)范圍(wei)(wei)內,這些關系不因(yin)電源(yuan)電壓、負(fu)載大小、環境條件(jian)的(de)(de)波動(dong)而變化,誤(wu)差(cha)不長期積累,步進(jin)(jin)電動(dong)機驅動(dong)系統可(ke)以在(zai)較(jiao)寬的(de)(de)范圍(wei)(wei)內,通過改變脈(mo)沖頻率來調(diao)速(su)(su),實現快速(su)(su)起動(dong)、正反轉(zhuan)制動(dong)。