1、液(ye)壓密封件之(zhi)形式選擇(ze)

　　在液壓(ya)系統(tong)中(zhong)，常(chang)見的(de)密封(feng)(feng)(feng)形(xing)式有擠(ji)壓(ya)型O形(xing)密封(feng)(feng)(feng)圈(quan)(quan)(quan)、Y形(xing)圈(quan)(quan)(quan)、V形(xing)圈(quan)(quan)(quan)、U形(xing)圈(quan)(quan)(quan)唇形(xing)密封(feng)(feng)(feng)。唇形(xing)密封(feng)(feng)(feng)圈(quan)(quan)(quan)主要用(yong)于往(wang)復動(dong)密封(feng)(feng)(feng)，與O形(xing)圈(quan)(quan)(quan)等(deng)擠(ji)壓(ya)密封(feng)(feng)(feng)相比，往(wang)復動(dong)密封(feng)(feng)(feng)使用(yong)唇形(xing)密封(feng)(feng)(feng)圈(quan)(quan)(quan)具有更好的(de)綜合性(xing)能和更長的(de)使用(yong)壽命。

　　唇形(xing)(xing)密封(feng)(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)的(de)(de)密封(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊力(li)(li)(li)是(shi)隨(sui)介質壓(ya)(ya)(ya)力(li)(li)(li)的(de)(de)改(gai)變而(er)(er)變化的(de)(de)，工作(zuo)中始終應監控介質壓(ya)(ya)(ya)力(li)(li)(li)的(de)(de)變化，即能(neng)保(bao)證足夠(gou)的(de)(de)密封(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊力(li)(li)(li)，又不(bu)至于(yu)產生過(guo)(guo)大的(de)(de)摩(mo)(mo)(mo)擦力(li)(li)(li)，擠壓(ya)(ya)(ya)性(xing)密封(feng)(feng)(feng)(feng)(feng)主要靠預壓(ya)(ya)(ya)緊力(li)(li)(li)產生密封(feng)(feng)(feng)(feng)(feng)力(li)(li)(li)，密封(feng)(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)接觸壓(ya)(ya)(ya)力(li)(li)(li)預先給(gei)定(ding)，工作(zuo)中不(bu)能(neng)根據介質壓(ya)(ya)(ya)力(li)(li)(li)的(de)(de)改(gai)變而(er)(er)變化。大的(de)(de)預壓(ya)(ya)(ya)力(li)(li)(li)會使密封(feng)(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)與密封(feng)(feng)(feng)(feng)(feng)面接觸面積增(zeng)大，產生很(hen)大的(de)(de)摩(mo)(mo)(mo)擦阻(zu)力(li)(li)(li)，過(guo)(guo)大的(de)(de)摩(mo)(mo)(mo)擦力(li)(li)(li)會造成密封(feng)(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)的(de)(de)破損，在低壓(ya)(ya)(ya)時造成啟動困難，或產生爬行現象，唇形(xing)(xing)密封(feng)(feng)(feng)(feng)(feng)圈(quan)(quan)(quan)(quan)可以通過(guo)(guo)唇部撐開，變形(xing)(xing)補(bu)償小(xiao)的(de)(de)磨損量，保(bao)證密封(feng)(feng)(feng)(feng)(feng)效果和密封(feng)(feng)(feng)(feng)(feng)壽命(ming);而(er)(er)O形(xing)(xing)圈(quan)(quan)(quan)(quan)隨(sui)著摩(mo)(mo)(mo)擦余(yu)量的(de)(de)減少，直接影響其(qi)密封(feng)(feng)(feng)(feng)(feng)性(xing)。

　　2、液壓密封件之材料(liao)選擇

　　密(mi)封(feng)(feng)(feng)件(jian)(jian)形式和結構(gou)現(xian)在(zai)(zai)一(yi)(yi)般已經定型(xing)，各(ge)密(mi)封(feng)(feng)(feng)件(jian)(jian)質(zhi)量(liang)區(qu)別主要在(zai)(zai)于制作材(cai)料(liao)(liao)(liao)上(shang)。密(mi)封(feng)(feng)(feng)材(cai)料(liao)(liao)(liao)主要使用(yong)(yong)橡膠和合(he)成樹脂。由于各(ge)種(zhong)材(cai)料(liao)(liao)(liao)性(xing)能特(te)點(dian)不同(tong)(tong)(tong)，性(xing)能特(te)點(dian)不同(tong)(tong)(tong)，用(yong)(yong)途也(ye)就(jiu)有(you)(you)(you)(you)所不同(tong)(tong)(tong)。選用(yong)(yong)時(shi)需根據(ju)不同(tong)(tong)(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)和不同(tong)(tong)(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)作出(chu)合(he)適的(de)(de)(de)選擇。另外，某一(yi)(yi)材(cai)質(zhi)的(de)(de)(de)密(mi)封(feng)(feng)(feng)對(dui)被密(mi)封(feng)(feng)(feng)的(de)(de)(de)某一(yi)(yi)工作介質(zhi)(如礦物油(you)等(deng))表現(xian)較好的(de)(de)(de)密(mi)封(feng)(feng)(feng)性(xing)能，而(er)對(dui)另一(yi)(yi)介質(zhi)表現(xian)極差，這就(jiu)是密(mi)封(feng)(feng)(feng)材(cai)料(liao)(liao)(liao)與液壓(ya)油(you)的(de)(de)(de)相容性(xing)。還有(you)(you)(you)(you)，各(ge)種(zhong)不同(tong)(tong)(tong)的(de)(de)(de)密(mi)封(feng)(feng)(feng)材(cai)料(liao)(liao)(liao)對(dui)你(ni)不同(tong)(tong)(tong)的(de)(de)(de)工作條件(jian)(jian)表現(xian)出(chu)不同(tong)(tong)(tong)的(de)(de)(de)性(xing)能。有(you)(you)(you)(you)些(xie)耐(nai)熱(re)，有(you)(you)(you)(you)些(xie)不耐(nai)熱(re);有(you)(you)(you)(you)些(xie)耐(nai)酸，有(you)(you)(you)(you)些(xie)耐(nai)堿，有(you)(you)(you)(you)些(xie)耐(nai)水，有(you)(you)(you)(you)些(xie)耐(nai)油(you);有(you)(you)(you)(you)些(xie)抗熱(re)，有(you)(you)(you)(you)些(xie)耐(nai)低溫(wen)，有(you)(you)(you)(you)些(xie)耐(nai)高(gao)溫(wen)，等(deng)等(deng)。這些(xie)因(yin)素在(zai)(zai)考慮密(mi)封(feng)(feng)(feng)件(jian)(jian)材(cai)料(liao)(liao)(liao)的(de)(de)(de)時(shi)候需注意。