塔吊(diao)的工作原(yuan)理是起(qi)重(zhong)機械(xie)通過起(qi)重(zhong)吊(diao)鉤或(huo)其它取物(wu)(wu)裝置起(qi)升或(huo)起(qi)升加移(yi)動重(zhong)物(wu)(wu)。起(qi)重(zhong)機械(xie)的工作過程一般包括起(qi)升、運行(xing)、下降及返回原(yuan)位等步驟。起(qi)升機構通過取物(wu)(wu)裝置從(cong)取物(wu)(wu)地點把重(zhong)物(wu)(wu)提起(qi)，經運行(xing)、回轉(zhuan)或(huo)變幅機構把重(zhong)物(wu)(wu)移(yi)位，在設定(ding)的地點下放重(zhong)物(wu)(wu)后返回到原(yuan)位。

常見的(de)(de)(de)驅(qu)(qu)(qu)(qu)動(dong)(dong)裝置有(you)電(dian)力驅(qu)(qu)(qu)(qu)動(dong)(dong)、內(nei)燃機(ji)驅(qu)(qu)(qu)(qu)動(dong)(dong)和人力驅(qu)(qu)(qu)(qu)動(dong)(dong)等(deng)。電(dian)能是(shi)清潔、經濟的(de)(de)(de)能源，電(dian)力驅(qu)(qu)(qu)(qu)動(dong)(dong)是(shi)現代起重機(ji)的(de)(de)(de)主要驅(qu)(qu)(qu)(qu)動(dong)(dong)型式，幾乎所有(you)的(de)(de)(de)在有(you)限范圍內(nei)運行(xing)的(de)(de)(de)有(you)軌起重機(ji)、升降機(ji)、電(dian)梯等(deng)都采用(yong)電(dian)力驅(qu)(qu)(qu)(qu)動(dong)(dong)。

對(dui)于可以遠距離移動(dong)的流動(dong)式(shi)起重機(ji)(如汽車(che)起重機(ji)、輪胎(tai)起重機(ji)和(he)履帶起重機(ji))多采用內燃機(ji)驅(qu)動(dong)。人力驅(qu)動(dong)適用于一些(xie)輕小(xiao)起重設(she)備，也用作(zuo)某些(xie)設(she)備的輔助、備用驅(qu)動(dong)和(he)意外(或事故狀態)的臨時動(dong)力。