1、液(ye)壓密封件(jian)之形式選擇

　　在液壓系統中，常見的(de)密(mi)(mi)封(feng)(feng)(feng)形(xing)(xing)(xing)式有擠壓型O形(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)、Y形(xing)(xing)(xing)圈(quan)(quan)(quan)、V形(xing)(xing)(xing)圈(quan)(quan)(quan)、U形(xing)(xing)(xing)圈(quan)(quan)(quan)唇形(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)。唇形(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)主要用(yong)于(yu)往(wang)復(fu)動密(mi)(mi)封(feng)(feng)(feng)，與O形(xing)(xing)(xing)圈(quan)(quan)(quan)等(deng)擠壓密(mi)(mi)封(feng)(feng)(feng)相(xiang)比，往(wang)復(fu)動密(mi)(mi)封(feng)(feng)(feng)使用(yong)唇形(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)具有更好的(de)綜合性能和更長的(de)使用(yong)壽命。

　　唇(chun)形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)緊(jin)力(li)(li)(li)是隨介質壓(ya)(ya)力(li)(li)(li)的(de)改(gai)變(bian)而(er)變(bian)化(hua)的(de)，工作(zuo)中(zhong)始(shi)終應監控介質壓(ya)(ya)力(li)(li)(li)的(de)變(bian)化(hua)，即(ji)能(neng)保證足(zu)夠(gou)的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)緊(jin)力(li)(li)(li)，又不至于產(chan)生(sheng)過大(da)的(de)摩擦(ca)力(li)(li)(li)，擠壓(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)(feng)主要靠預壓(ya)(ya)緊(jin)力(li)(li)(li)產(chan)生(sheng)密(mi)(mi)(mi)(mi)封(feng)(feng)力(li)(li)(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)接觸壓(ya)(ya)力(li)(li)(li)預先給(gei)定(ding)，工作(zuo)中(zhong)不能(neng)根(gen)據介質壓(ya)(ya)力(li)(li)(li)的(de)改(gai)變(bian)而(er)變(bian)化(hua)。大(da)的(de)預壓(ya)(ya)力(li)(li)(li)會使密(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)與密(mi)(mi)(mi)(mi)封(feng)(feng)面接觸面積(ji)增大(da)，產(chan)生(sheng)很大(da)的(de)摩擦(ca)阻力(li)(li)(li)，過大(da)的(de)摩擦(ca)力(li)(li)(li)會造成密(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)的(de)破損(sun)，在低壓(ya)(ya)時(shi)造成啟動(dong)困(kun)難，或(huo)產(chan)生(sheng)爬行現象，唇(chun)形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)可以通過唇(chun)部撐開，變(bian)形(xing)補(bu)償小的(de)磨損(sun)量，保證密(mi)(mi)(mi)(mi)封(feng)(feng)效果和密(mi)(mi)(mi)(mi)封(feng)(feng)壽命;而(er)O形(xing)圈(quan)隨著(zhu)摩擦(ca)余量的(de)減少，直接影響其密(mi)(mi)(mi)(mi)封(feng)(feng)性。

　　2、液壓密(mi)封件(jian)之材料選擇

　　密(mi)封(feng)件(jian)(jian)(jian)形(xing)式和結構現在(zai)(zai)一般已經定型，各(ge)密(mi)封(feng)件(jian)(jian)(jian)質量區別主(zhu)要(yao)(yao)在(zai)(zai)于制作(zuo)材(cai)(cai)(cai)料上。密(mi)封(feng)材(cai)(cai)(cai)料主(zhu)要(yao)(yao)使用(yong)(yong)橡(xiang)膠和合成樹脂。由于各(ge)種材(cai)(cai)(cai)料性(xing)能(neng)特點不(bu)(bu)同(tong)(tong)，性(xing)能(neng)特點不(bu)(bu)同(tong)(tong)，用(yong)(yong)途也就有(you)(you)所不(bu)(bu)同(tong)(tong)。選用(yong)(yong)時(shi)需(xu)根(gen)據(ju)不(bu)(bu)同(tong)(tong)的(de)(de)使用(yong)(yong)條(tiao)件(jian)(jian)(jian)和不(bu)(bu)同(tong)(tong)的(de)(de)使用(yong)(yong)條(tiao)件(jian)(jian)(jian)作(zuo)出合適的(de)(de)選擇。另外，某一材(cai)(cai)(cai)質的(de)(de)密(mi)封(feng)對(dui)被密(mi)封(feng)的(de)(de)某一工作(zuo)介質(如礦物油(you)(you)等)表(biao)(biao)現較好的(de)(de)密(mi)封(feng)性(xing)能(neng)，而對(dui)另一介質表(biao)(biao)現極(ji)差，這就是(shi)密(mi)封(feng)材(cai)(cai)(cai)料與(yu)液壓油(you)(you)的(de)(de)相容性(xing)。還(huan)有(you)(you)，各(ge)種不(bu)(bu)同(tong)(tong)的(de)(de)密(mi)封(feng)材(cai)(cai)(cai)料對(dui)你不(bu)(bu)同(tong)(tong)的(de)(de)工作(zuo)條(tiao)件(jian)(jian)(jian)表(biao)(biao)現出不(bu)(bu)同(tong)(tong)的(de)(de)性(xing)能(neng)。有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)熱，有(you)(you)些(xie)(xie)(xie)(xie)不(bu)(bu)耐(nai)熱;有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)酸(suan)，有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)堿(jian)，有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)水，有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)油(you)(you);有(you)(you)些(xie)(xie)(xie)(xie)抗(kang)熱，有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)低溫，有(you)(you)些(xie)(xie)(xie)(xie)耐(nai)高溫，等等。這些(xie)(xie)(xie)(xie)因素在(zai)(zai)考慮密(mi)封(feng)件(jian)(jian)(jian)材(cai)(cai)(cai)料的(de)(de)時(shi)候(hou)需(xu)注(zhu)意。