液(ye)(ye)壓(ya)(ya)(ya)傳動是以液(ye)(ye)體(ti)為工作介質，利用液(ye)(ye)體(ti)的(de)壓(ya)(ya)(ya)力(li)能(neng)(neng)(neng)來(lai)實(shi)(shi)現運動和力(li)的(de)一種傳動方(fang)式。一般(ban)而言(yan)，能(neng)(neng)(neng)夠實(shi)(shi)現某種特定功能(neng)(neng)(neng)的(de)液(ye)(ye)壓(ya)(ya)(ya)元(yuan)(yuan)件(jian)(jian)的(de)組合(he)，稱(cheng)(cheng)為液(ye)(ye)壓(ya)(ya)(ya)回(hui)路，而若干特定的(de)基本功能(neng)(neng)(neng)回(hui)路連接或復合(he)而成的(de)總體(ti)則(ze)稱(cheng)(cheng)為直(zhi)流液(ye)(ye)壓(ya)(ya)(ya)動力(li)單元(yuan)(yuan)。直(zhi)流液(ye)(ye)壓(ya)(ya)(ya)動力(li)單元(yuan)(yuan)通常都是由液(ye)(ye)壓(ya)(ya)(ya)元(yuan)(yuan)件(jian)(jian)（動力(li)元(yuan)(yuan)件(jian)(jian)、執行元(yuan)(yuan)件(jian)(jian)、控(kong)制(zhi)元(yuan)(yuan)件(jian)(jian)、輔助元(yuan)(yuan)件(jian)(jian)）和工作介質兩大部分組成。

直流液壓動力(li)單元型號規格：