1、液壓密封件之形式(shi)選擇

　　在(zai)液壓(ya)系統(tong)中，常(chang)見的(de)密(mi)封形(xing)式有擠壓(ya)型O形(xing)密(mi)封圈(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(mi)封。唇形(xing)密(mi)封圈(quan)(quan)(quan)主要(yao)用于往復(fu)動密(mi)封，與O形(xing)圈(quan)(quan)(quan)等擠壓(ya)密(mi)封相(xiang)比(bi)，往復(fu)動密(mi)封使用唇形(xing)密(mi)封圈(quan)(quan)(quan)具有更(geng)好的(de)綜合性能和更(geng)長的(de)使用壽命(ming)。

　　唇形(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)圈的密(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)(ya)緊力(li)是(shi)隨介(jie)質(zhi)壓(ya)(ya)(ya)力(li)的改(gai)變(bian)而(er)(er)變(bian)化(hua)的，工(gong)(gong)作(zuo)中(zhong)(zhong)始終應監控介(jie)質(zhi)壓(ya)(ya)(ya)力(li)的變(bian)化(hua)，即能(neng)保(bao)證(zheng)足夠的密(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)(ya)緊力(li)，又不至(zhi)于產(chan)(chan)生(sheng)過(guo)大(da)(da)(da)的摩擦力(li)，擠壓(ya)(ya)(ya)性密(mi)(mi)封(feng)(feng)(feng)主要靠預(yu)壓(ya)(ya)(ya)緊力(li)產(chan)(chan)生(sheng)密(mi)(mi)封(feng)(feng)(feng)力(li)，密(mi)(mi)封(feng)(feng)(feng)圈接觸(chu)壓(ya)(ya)(ya)力(li)預(yu)先(xian)給定，工(gong)(gong)作(zuo)中(zhong)(zhong)不能(neng)根據介(jie)質(zhi)壓(ya)(ya)(ya)力(li)的改(gai)變(bian)而(er)(er)變(bian)化(hua)。大(da)(da)(da)的預(yu)壓(ya)(ya)(ya)力(li)會使密(mi)(mi)封(feng)(feng)(feng)圈與密(mi)(mi)封(feng)(feng)(feng)面(mian)接觸(chu)面(mian)積增大(da)(da)(da)，產(chan)(chan)生(sheng)很大(da)(da)(da)的摩擦阻(zu)力(li)，過(guo)大(da)(da)(da)的摩擦力(li)會造(zao)成(cheng)密(mi)(mi)封(feng)(feng)(feng)圈的破損，在(zai)低壓(ya)(ya)(ya)時造(zao)成(cheng)啟動困難(nan)，或(huo)產(chan)(chan)生(sheng)爬行現象，唇形(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)圈可以通過(guo)唇部(bu)撐開，變(bian)形(xing)(xing)補償小的磨損量，保(bao)證(zheng)密(mi)(mi)封(feng)(feng)(feng)效果和密(mi)(mi)封(feng)(feng)(feng)壽命;而(er)(er)O形(xing)(xing)圈隨著(zhu)摩擦余量的減少，直接影(ying)響其密(mi)(mi)封(feng)(feng)(feng)性。

　　2、液(ye)壓密封件之材料選(xuan)擇

　　密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件形式和(he)(he)結構現(xian)在(zai)一(yi)(yi)般已經定型(xing)，各密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件質(zhi)量區別主要(yao)在(zai)于制作材(cai)料(liao)(liao)上。密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)料(liao)(liao)主要(yao)使(shi)(shi)用(yong)橡膠和(he)(he)合成(cheng)樹脂。由于各種(zhong)材(cai)料(liao)(liao)性(xing)(xing)能(neng)特(te)點(dian)不(bu)(bu)(bu)同(tong)，性(xing)(xing)能(neng)特(te)點(dian)不(bu)(bu)(bu)同(tong)，用(yong)途(tu)也就(jiu)有(you)(you)所不(bu)(bu)(bu)同(tong)。選(xuan)用(yong)時需(xu)根(gen)據不(bu)(bu)(bu)同(tong)的(de)使(shi)(shi)用(yong)條件和(he)(he)不(bu)(bu)(bu)同(tong)的(de)使(shi)(shi)用(yong)條件作出合適的(de)選(xuan)擇。另外，某(mou)一(yi)(yi)材(cai)質(zhi)的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)對(dui)被(bei)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)的(de)某(mou)一(yi)(yi)工作介質(zhi)(如礦物油等)表現(xian)較好的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)性(xing)(xing)能(neng)，而(er)對(dui)另一(yi)(yi)介質(zhi)表現(xian)極差，這(zhe)就(jiu)是密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)料(liao)(liao)與液壓(ya)油的(de)相容性(xing)(xing)。還(huan)有(you)(you)，各種(zhong)不(bu)(bu)(bu)同(tong)的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)料(liao)(liao)對(dui)你不(bu)(bu)(bu)同(tong)的(de)工作條件表現(xian)出不(bu)(bu)(bu)同(tong)的(de)性(xing)(xing)能(neng)。有(you)(you)些(xie)(xie)(xie)耐(nai)熱，有(you)(you)些(xie)(xie)(xie)不(bu)(bu)(bu)耐(nai)熱;有(you)(you)些(xie)(xie)(xie)耐(nai)酸(suan)，有(you)(you)些(xie)(xie)(xie)耐(nai)堿(jian)，有(you)(you)些(xie)(xie)(xie)耐(nai)水(shui)，有(you)(you)些(xie)(xie)(xie)耐(nai)油;有(you)(you)些(xie)(xie)(xie)抗熱，有(you)(you)些(xie)(xie)(xie)耐(nai)低(di)溫(wen)，有(you)(you)些(xie)(xie)(xie)耐(nai)高溫(wen)，等等。這(zhe)些(xie)(xie)(xie)因素在(zai)考慮(lv)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件材(cai)料(liao)(liao)的(de)時候需(xu)注意。