塔吊的工(gong)作原理(li)是起(qi)重(zhong)(zhong)(zhong)(zhong)機(ji)械(xie)通過(guo)起(qi)重(zhong)(zhong)(zhong)(zhong)吊鉤或(huo)(huo)其它取物(wu)(wu)裝置起(qi)升或(huo)(huo)起(qi)升加移(yi)動重(zhong)(zhong)(zhong)(zhong)物(wu)(wu)。起(qi)重(zhong)(zhong)(zhong)(zhong)機(ji)械(xie)的工(gong)作過(guo)程(cheng)一般包括起(qi)升、運行(xing)、下(xia)降及返回原位等步驟。起(qi)升機(ji)構(gou)通過(guo)取物(wu)(wu)裝置從取物(wu)(wu)地點(dian)把(ba)重(zhong)(zhong)(zhong)(zhong)物(wu)(wu)提(ti)起(qi)，經(jing)運行(xing)、回轉或(huo)(huo)變幅機(ji)構(gou)把(ba)重(zhong)(zhong)(zhong)(zhong)物(wu)(wu)移(yi)位，在設定(ding)的地點(dian)下(xia)放(fang)重(zhong)(zhong)(zhong)(zhong)物(wu)(wu)后返回到(dao)原位。

常見的驅(qu)動(dong)(dong)裝置有電力(li)(li)(li)驅(qu)動(dong)(dong)、內燃(ran)機(ji)驅(qu)動(dong)(dong)和人力(li)(li)(li)驅(qu)動(dong)(dong)等。電能是清(qing)潔、經濟的能源(yuan)，電力(li)(li)(li)驅(qu)動(dong)(dong)是現代起(qi)重機(ji)的主要驅(qu)動(dong)(dong)型式，幾乎所(suo)有的在(zai)有限范圍內運行的有軌起(qi)重機(ji)、升(sheng)降機(ji)、電梯等都采(cai)用電力(li)(li)(li)驅(qu)動(dong)(dong)。

對于可以(yi)遠距離移(yi)動(dong)的流動(dong)式(shi)起(qi)重(zhong)(zhong)(zhong)機(ji)(ji)(如汽車起(qi)重(zhong)(zhong)(zhong)機(ji)(ji)、輪胎起(qi)重(zhong)(zhong)(zhong)機(ji)(ji)和(he)履(lv)帶(dai)起(qi)重(zhong)(zhong)(zhong)機(ji)(ji))多采用(yong)內燃機(ji)(ji)驅動(dong)。人力驅動(dong)適用(yong)于一些(xie)輕(qing)小起(qi)重(zhong)(zhong)(zhong)設備，也用(yong)作(zuo)某些(xie)設備的輔助、備用(yong)驅動(dong)和(he)意外(或事故狀(zhuang)態)的臨時(shi)動(dong)力。