起重機是指在一定範圍內垂直提升和水平搬運重物的多動作起重機械。又稱天車，航吊，吊車. 起重機主要包括起升機構、運行機構、變幅機構


、huizhuanjigouhejinshujiegoudeng。qishengjigoushiqizhongjidejibengongzuojigou，daduoshiyoudiaoguaxitonghejiaochezucheng，yeyoutongguoyeyaxitongshengjiangzhongwude。yunxingjigouyongyizongxiangshuipingyunyizhongwuhuotiaozhengqizhongjidegongzuoweizhi
，yibanshiyoudiandongji
、減速器、zhidongqihechelunzucheng。bianfujigouzhipeibeizaibijiaxingqizhongjishang，bijiayangqishifudujianxiao，fuxiashifuduzengda
，fenpinghengbianfuhefeipinghengbianfuliangzhong。huizhuanjigouyongyishibijiahuizhuan
，shiyouqudongzhuangzhihehuizhuanzhichengzhuangzhizucheng。jinshujiegoushiqizhongjidegujia，zhuyaochengzaijianruqiaojia
、臂架和門架可為箱形結構或桁架結構，也可為腹板結構，有的可用型鋼作為支承梁。