塔吊的工(gong)作原理是起(qi)(qi)重(zhong)機(ji)械通過起(qi)(qi)重(zhong)吊鉤或其它取物(wu)(wu)裝(zhuang)置起(qi)(qi)升(sheng)或起(qi)(qi)升(sheng)加移(yi)動重(zhong)物(wu)(wu)。起(qi)(qi)重(zhong)機(ji)械的工(gong)作過程一般包(bao)括起(qi)(qi)升(sheng)、運(yun)行、下降(jiang)及(ji)返回原位等步(bu)驟(zou)。起(qi)(qi)升(sheng)機(ji)構(gou)(gou)通過取物(wu)(wu)裝(zhuang)置從取物(wu)(wu)地(di)點(dian)把(ba)重(zhong)物(wu)(wu)提起(qi)(qi)，經運(yun)行、回轉或變幅機(ji)構(gou)(gou)把(ba)重(zhong)物(wu)(wu)移(yi)位，在(zai)設定的地(di)點(dian)下放重(zhong)物(wu)(wu)后返回到原位。

常見的(de)(de)驅(qu)(qu)(qu)動裝置有(you)電力(li)驅(qu)(qu)(qu)動、內燃機(ji)(ji)(ji)驅(qu)(qu)(qu)動和人力(li)驅(qu)(qu)(qu)動等。電能(neng)是(shi)清潔、經濟的(de)(de)能(neng)源(yuan)，電力(li)驅(qu)(qu)(qu)動是(shi)現代起重(zhong)機(ji)(ji)(ji)的(de)(de)主(zhu)要驅(qu)(qu)(qu)動型式，幾乎所有(you)的(de)(de)在有(you)限范圍(wei)內運行的(de)(de)有(you)軌起重(zhong)機(ji)(ji)(ji)、升降(jiang)機(ji)(ji)(ji)、電梯等都采用(yong)電力(li)驅(qu)(qu)(qu)動。

對于可以遠(yuan)距(ju)離移動(dong)的(de)流動(dong)式起(qi)(qi)重機(ji)(如汽車起(qi)(qi)重機(ji)、輪胎起(qi)(qi)重機(ji)和履帶起(qi)(qi)重機(ji))多采用(yong)(yong)內燃(ran)機(ji)驅動(dong)。人力驅動(dong)適用(yong)(yong)于一些輕小起(qi)(qi)重設(she)備(bei)(bei)，也用(yong)(yong)作某些設(she)備(bei)(bei)的(de)輔(fu)助(zhu)、備(bei)(bei)用(yong)(yong)驅動(dong)和意外(wai)(或事故狀(zhuang)態(tai))的(de)臨時動(dong)力。