塔吊的工作原(yuan)理(li)是起(qi)(qi)(qi)重(zhong)(zhong)機械(xie)通過起(qi)(qi)(qi)重(zhong)(zhong)吊鉤(gou)或其它(ta)取(qu)物(wu)(wu)(wu)裝置起(qi)(qi)(qi)升(sheng)或起(qi)(qi)(qi)升(sheng)加移(yi)動重(zhong)(zhong)物(wu)(wu)(wu)。起(qi)(qi)(qi)重(zhong)(zhong)機械(xie)的工作過程一(yi)般(ban)包括(kuo)起(qi)(qi)(qi)升(sheng)、運(yun)(yun)行、下降及(ji)返(fan)回原(yuan)位等步驟。起(qi)(qi)(qi)升(sheng)機構通過取(qu)物(wu)(wu)(wu)裝置從(cong)取(qu)物(wu)(wu)(wu)地點把重(zhong)(zhong)物(wu)(wu)(wu)提起(qi)(qi)(qi)，經運(yun)(yun)行、回轉或變幅機構把重(zhong)(zhong)物(wu)(wu)(wu)移(yi)位，在(zai)設定(ding)的地點下放重(zhong)(zhong)物(wu)(wu)(wu)后返(fan)回到原(yuan)位。

常見(jian)的驅(qu)(qu)動(dong)裝置有(you)電力(li)驅(qu)(qu)動(dong)、內燃機驅(qu)(qu)動(dong)和人力(li)驅(qu)(qu)動(dong)等(deng)。電能(neng)是(shi)清潔、經濟的能(neng)源，電力(li)驅(qu)(qu)動(dong)是(shi)現代起(qi)重機的主要驅(qu)(qu)動(dong)型式，幾(ji)乎所有(you)的在(zai)有(you)限范(fan)圍內運行(xing)的有(you)軌起(qi)重機、升降(jiang)機、電梯等(deng)都采用(yong)電力(li)驅(qu)(qu)動(dong)。

對于可以遠距離(li)移動(dong)的(de)流動(dong)式起(qi)重(zhong)機(ji)(ji)(如汽車起(qi)重(zhong)機(ji)(ji)、輪胎起(qi)重(zhong)機(ji)(ji)和履帶起(qi)重(zhong)機(ji)(ji))多采用(yong)內燃機(ji)(ji)驅(qu)動(dong)。人力(li)驅(qu)動(dong)適用(yong)于一些輕小(xiao)起(qi)重(zhong)設(she)備，也用(yong)作(zuo)某些設(she)備的(de)輔助、備用(yong)驅(qu)動(dong)和意外(或事故狀(zhuang)態)的(de)臨時動(dong)力(li)。