液(ye)(ye)壓(ya)油(you)(you)(you)(you)是一(yi)種潤滑油(you)(you)(you)(you)，用(yong)作液(ye)(ye)壓(ya)傳動系(xi)統(tong)中(zhong)的(de)(de)工作介質。據(ju)(ju)相(xiang)關(guan)的(de)(de)統(tong)計質料表明，液(ye)(ye)壓(ya)系(xi)統(tong)出現的(de)(de)各(ge)類故障原因，有(you)60%~70與液(ye)(ye)壓(ya)油(you)(you)(you)(you)是有(you)關(guan)系(xi)的(de)(de)。液(ye)(ye)壓(ya)油(you)(you)(you)(you)在(zai)(zai)液(ye)(ye)壓(ya)系(xi)統(tong)中(zhong)有(you)著重要的(de)(de)作用(yong)，在(zai)(zai)液(ye)(ye)壓(ya)系(xi)統(tong)中(zhong)起著能(neng)量(liang)傳遞、抗(kang)磨、體(ti)系(xi)光滑、防(fang)腐、防(fang)銹、冷卻等(deng)作用(yong)。液(ye)(ye)壓(ya)油(you)(you)(you)(you)的(de)(de)品種多(duo)樣，液(ye)(ye)壓(ya)油(you)(you)(you)(you)多(duo)少錢一(yi)桶，油(you)(you)(you)(you)多(duo)種分類，根據(ju)(ju)不同的(de)(de)需求和(he)特性(xing)油(you)(you)(you)(you)分為(wei)抗(kang)磨液(ye)(ye)壓(ya)油(you)(you)(you)(you)、無灰抗(kang)磨液(ye)(ye)壓(ya)油(you)(you)(you)(you)、抗(kang)燃液(ye)(ye)壓(ya)油(you)(you)(you)(you)、可生物降解液(ye)(ye)壓(ya)油(you)(you)(you)(you)等(deng)類型。

食(shi)品級液(ye)壓油的選擇，主要應考慮以下三方面：

一(yi)、液壓(ya)(ya)油的(de)性(xing)及(ji)(ji)熱(re)穩定性(xing)。液壓(ya)(ya)油的(de)性(xing)及(ji)(ji)抗熱(re)分解性(xing)可(ke)使(shi)液壓(ya)(ya)系統免(mian)受油泥及(ji)(ji)漆膜的(de)影響，從而保證(zheng)液壓(ya)(ya)閥門(men)及(ji)(ji)驅動裝置的(de)平滑和可(ke)靠運轉(zhuan)。

二(er)、磨損保護(hu)。液壓油應該保護(hu)金屬泵體(ti)免受劃痕(hen)的影(ying)響，通過延長液壓系統的使用(yong)壽命降低(di)總體(ti)維(wei)護(hu)成(cheng)本。

三、防(fang)止泡沫及氣泡產生。液(ye)壓油應該防(fang)止液(ye)壓系統中產生溢(yi)流現(xian)象，消(xiao)除內部(bu)空隙，減少因氣蝕帶來的損害。

液(ye)(ye)體(ti)在(zai)外(wai)力作用(yong)積不(bu)(bu)易(yi)發生變化(hua)，但液(ye)(ye)體(ti)中(zhong)混入空(kong)(kong)氣(qi)后就會(hui)使其(qi)壓(ya)(ya)縮性受(shou)到(dao)影(ying)響(xiang)(xiang)(xiang)。保持液(ye)(ye)壓(ya)(ya)油(you)(you)(you)的不(bu)(bu)可(ke)(ke)壓(ya)(ya)縮性，對于(yu)液(ye)(ye)壓(ya)(ya)油(you)(you)(you)作為(wei)工(gong)作介質可(ke)(ke)靠地傳遞能(neng)(neng)量、確(que)保操縱機構靈(ling)敏動作是至關(guan)重要(yao)的。目(mu)前使用(yong)的液(ye)(ye)壓(ya)(ya)油(you)(you)(you)多為(wei)石油(you)(you)(you)型(xing)的，合(he)肥液(ye)(ye)壓(ya)(ya)油(you)(you)(you)，空(kong)(kong)氣(qi)能(neng)(neng)溶(rong)解于(yu)油(you)(you)(you)中(zhong)，其(qi)溶(rong)解度主(zhu)要(yao)取決于(yu)空(kong)(kong)氣(qi)壓(ya)(ya)力及溫(wen)度。當(dang)空(kong)(kong)氣(qi)在(zai)油(you)(you)(you)液(ye)(ye)中(zhong)保持溶(rong)解狀態時(shi)，液(ye)(ye)壓(ya)(ya)系統并(bing)不(bu)(bu)出現問題，工(gong)業液(ye)(ye)壓(ya)(ya)油(you)(you)(you)，但當(dang)液(ye)(ye)壓(ya)(ya)油(you)(you)(you)通過(guo)油(you)(you)(you)缸、閥門或其(qi)它液(ye)(ye)壓(ya)(ya)元件時(shi)，壓(ya)(ya)力有時(shi)會(hui)突然(ran)降低，液(ye)(ye)壓(ya)(ya)油(you)(you)(you)價(jia)格，加之溫(wen)度變化(hua)的影(ying)響(xiang)(xiang)(xiang)，使得空(kong)(kong)氣(qi)易(yi)從油(you)(you)(you)液(ye)(ye)中(zhong)釋放(fang)出來并(bing)形成許多氣(qi)泡，這將使液(ye)(ye)壓(ya)(ya)油(you)(you)(you)的不(bu)(bu)可(ke)(ke)壓(ya)(ya)縮性受(shou)到(dao)影(ying)響(xiang)(xiang)(xiang)。