門式起重機(又稱龍門起重機)是橋架通過兩側支腿支撐在地麵軌道上的橋架型起重機。在結構上由門架、大車運行機構、起qi重zhong小xiao車che和he電dian氣qi部bu分fen等deng組zu成cheng。有you的de門men式shi起qi重zhong機ji隻zhi在zai一yi側ce有you支zhi腿tui，另ling一yi側ce支zhi撐cheng在zai廠chang房fang或huo棧zhan橋qiao上shang運yun行xing
，稱cheng作zuo半ban門men式shi起qi重zhong機ji。門men式shi起qi重zhong機ji的de門men架jia上shang部bu橋qiao架jia(含主梁和端梁)、支腿、xiahengliangdengbufengoucheng。weilekuodaqizhongjizuoyefanwei，zhuliangkeyixiangyicehuoliangceshenchuzhituiyiwai，xingchengxuanbi。yekecaiyongdaibijiadeqizhongxiaoche，tongguobijiadefuyanghexuanzhuankuodaqizhongjizuoyefanwei