1、液壓密封件之形式選擇(ze)

　　在(zai)液壓系統中，常(chang)見的密(mi)(mi)封形(xing)(xing)(xing)式有擠壓型(xing)O形(xing)(xing)(xing)密(mi)(mi)封圈(quan)(quan)、Y形(xing)(xing)(xing)圈(quan)(quan)、V形(xing)(xing)(xing)圈(quan)(quan)、U形(xing)(xing)(xing)圈(quan)(quan)唇形(xing)(xing)(xing)密(mi)(mi)封。唇形(xing)(xing)(xing)密(mi)(mi)封圈(quan)(quan)主要(yao)用于往復動密(mi)(mi)封，與O形(xing)(xing)(xing)圈(quan)(quan)等擠壓密(mi)(mi)封相比，往復動密(mi)(mi)封使(shi)用唇形(xing)(xing)(xing)密(mi)(mi)封圈(quan)(quan)具有更(geng)好(hao)的綜合性能(neng)和更(geng)長的使(shi)用壽命(ming)。

　　唇(chun)形密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)是(shi)隨介(jie)質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)的(de)(de)改(gai)變(bian)而(er)變(bian)化(hua)的(de)(de)，工作(zuo)(zuo)中(zhong)始終應監(jian)控(kong)介(jie)質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)的(de)(de)變(bian)化(hua)，即能保(bao)證足(zu)夠(gou)的(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)，又不(bu)至(zhi)于產(chan)生(sheng)過大的(de)(de)摩(mo)擦(ca)力(li)(li)，擠(ji)壓(ya)(ya)(ya)(ya)性密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)主要靠預壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)產(chan)生(sheng)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)力(li)(li)，密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈接觸壓(ya)(ya)(ya)(ya)力(li)(li)預先給(gei)定，工作(zuo)(zuo)中(zhong)不(bu)能根據介(jie)質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)的(de)(de)改(gai)變(bian)而(er)變(bian)化(hua)。大的(de)(de)預壓(ya)(ya)(ya)(ya)力(li)(li)會(hui)使(shi)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈與密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)面(mian)(mian)接觸面(mian)(mian)積(ji)增大，產(chan)生(sheng)很大的(de)(de)摩(mo)擦(ca)阻力(li)(li)，過大的(de)(de)摩(mo)擦(ca)力(li)(li)會(hui)造(zao)成(cheng)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)破損(sun)，在低壓(ya)(ya)(ya)(ya)時造(zao)成(cheng)啟動困難，或產(chan)生(sheng)爬行現象，唇(chun)形密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈可以通過唇(chun)部撐開，變(bian)形補償小的(de)(de)磨損(sun)量，保(bao)證密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)效(xiao)果和密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壽命;而(er)O形圈隨著(zhu)摩(mo)擦(ca)余量的(de)(de)減少，直接影(ying)響其密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)性。

　　2、液壓密封件之材(cai)料選擇

　　密(mi)封(feng)(feng)(feng)件形式和(he)結構現在(zai)(zai)一(yi)(yi)(yi)般已經定型，各密(mi)封(feng)(feng)(feng)件質量區(qu)別主要在(zai)(zai)于制作(zuo)材(cai)料(liao)上。密(mi)封(feng)(feng)(feng)材(cai)料(liao)主要使用(yong)(yong)(yong)橡(xiang)膠和(he)合(he)成樹脂。由于各種(zhong)材(cai)料(liao)性(xing)(xing)(xing)能特點不(bu)(bu)同(tong)，性(xing)(xing)(xing)能特點不(bu)(bu)同(tong)，用(yong)(yong)(yong)途也(ye)就有(you)(you)(you)所不(bu)(bu)同(tong)。選用(yong)(yong)(yong)時需根據(ju)不(bu)(bu)同(tong)的(de)使用(yong)(yong)(yong)條(tiao)(tiao)件和(he)不(bu)(bu)同(tong)的(de)使用(yong)(yong)(yong)條(tiao)(tiao)件作(zuo)出(chu)合(he)適的(de)選擇。另外，某一(yi)(yi)(yi)材(cai)質的(de)密(mi)封(feng)(feng)(feng)對(dui)被密(mi)封(feng)(feng)(feng)的(de)某一(yi)(yi)(yi)工作(zuo)介質(如礦物油等)表現較好的(de)密(mi)封(feng)(feng)(feng)性(xing)(xing)(xing)能，而對(dui)另一(yi)(yi)(yi)介質表現極差，這就是(shi)密(mi)封(feng)(feng)(feng)材(cai)料(liao)與液壓(ya)油的(de)相容性(xing)(xing)(xing)。還有(you)(you)(you)，各種(zhong)不(bu)(bu)同(tong)的(de)密(mi)封(feng)(feng)(feng)材(cai)料(liao)對(dui)你不(bu)(bu)同(tong)的(de)工作(zuo)條(tiao)(tiao)件表現出(chu)不(bu)(bu)同(tong)的(de)性(xing)(xing)(xing)能。有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)熱，有(you)(you)(you)些(xie)(xie)(xie)不(bu)(bu)耐(nai)(nai)熱;有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)酸，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)堿，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)水，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)油;有(you)(you)(you)些(xie)(xie)(xie)抗熱，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)低溫(wen)，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)高溫(wen)，等等。這些(xie)(xie)(xie)因素在(zai)(zai)考(kao)慮密(mi)封(feng)(feng)(feng)件材(cai)料(liao)的(de)時候需注意。