1、液壓密封件(jian)之(zhi)形式選擇

　　在液壓系(xi)統中，常(chang)見(jian)的(de)密(mi)封形(xing)(xing)式有擠壓型O形(xing)(xing)密(mi)封圈(quan)、Y形(xing)(xing)圈(quan)、V形(xing)(xing)圈(quan)、U形(xing)(xing)圈(quan)唇(chun)形(xing)(xing)密(mi)封。唇(chun)形(xing)(xing)密(mi)封圈(quan)主要用(yong)于往復動(dong)密(mi)封，與O形(xing)(xing)圈(quan)等擠壓密(mi)封相(xiang)比，往復動(dong)密(mi)封使(shi)用(yong)唇(chun)形(xing)(xing)密(mi)封圈(quan)具有更好(hao)的(de)綜合性能和更長的(de)使(shi)用(yong)壽命。

　　唇(chun)形(xing)(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊(jin)力(li)(li)是隨(sui)介質(zhi)(zhi)壓(ya)(ya)(ya)力(li)(li)的(de)(de)(de)改(gai)變(bian)(bian)(bian)而(er)變(bian)(bian)(bian)化的(de)(de)(de)，工(gong)作中始終應監控介質(zhi)(zhi)壓(ya)(ya)(ya)力(li)(li)的(de)(de)(de)變(bian)(bian)(bian)化，即能保(bao)(bao)證足夠(gou)的(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊(jin)力(li)(li)，又不至于產(chan)(chan)(chan)生(sheng)過大的(de)(de)(de)摩擦力(li)(li)，擠(ji)壓(ya)(ya)(ya)性密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)主(zhu)要靠預(yu)壓(ya)(ya)(ya)緊(jin)力(li)(li)產(chan)(chan)(chan)生(sheng)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)力(li)(li)，密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)接觸壓(ya)(ya)(ya)力(li)(li)預(yu)先(xian)給定，工(gong)作中不能根據介質(zhi)(zhi)壓(ya)(ya)(ya)力(li)(li)的(de)(de)(de)改(gai)變(bian)(bian)(bian)而(er)變(bian)(bian)(bian)化。大的(de)(de)(de)預(yu)壓(ya)(ya)(ya)力(li)(li)會使密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)與密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)面(mian)(mian)接觸面(mian)(mian)積增(zeng)大，產(chan)(chan)(chan)生(sheng)很大的(de)(de)(de)摩擦阻力(li)(li)，過大的(de)(de)(de)摩擦力(li)(li)會造成密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的(de)(de)(de)破(po)損，在低壓(ya)(ya)(ya)時造成啟動困難(nan)，或產(chan)(chan)(chan)生(sheng)爬行現象，唇(chun)形(xing)(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)可(ke)以通過唇(chun)部撐(cheng)開(kai)，變(bian)(bian)(bian)形(xing)(xing)補償小的(de)(de)(de)磨損量，保(bao)(bao)證密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)效果和(he)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壽命;而(er)O形(xing)(xing)圈(quan)隨(sui)著摩擦余量的(de)(de)(de)減少，直接影(ying)響其密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)性。

　　2、液(ye)壓密(mi)封件之材(cai)料選擇

　　密(mi)封(feng)(feng)(feng)件形(xing)式和(he)結構現(xian)在(zai)一般已經定(ding)型，各(ge)(ge)密(mi)封(feng)(feng)(feng)件質量區別主(zhu)(zhu)要(yao)在(zai)于制作(zuo)材(cai)料(liao)上。密(mi)封(feng)(feng)(feng)材(cai)料(liao)主(zhu)(zhu)要(yao)使用(yong)(yong)(yong)橡(xiang)膠(jiao)和(he)合成(cheng)樹脂。由于各(ge)(ge)種(zhong)材(cai)料(liao)性(xing)能特點(dian)(dian)不(bu)同(tong)(tong)(tong)，性(xing)能特點(dian)(dian)不(bu)同(tong)(tong)(tong)，用(yong)(yong)(yong)途也就有(you)(you)所不(bu)同(tong)(tong)(tong)。選用(yong)(yong)(yong)時需(xu)根據不(bu)同(tong)(tong)(tong)的(de)(de)(de)使用(yong)(yong)(yong)條件和(he)不(bu)同(tong)(tong)(tong)的(de)(de)(de)使用(yong)(yong)(yong)條件作(zuo)出合適的(de)(de)(de)選擇。另(ling)外，某一材(cai)質的(de)(de)(de)密(mi)封(feng)(feng)(feng)對被密(mi)封(feng)(feng)(feng)的(de)(de)(de)某一工作(zuo)介質(如(ru)礦(kuang)物(wu)油等)表(biao)現(xian)較好的(de)(de)(de)密(mi)封(feng)(feng)(feng)性(xing)能，而對另(ling)一介質表(biao)現(xian)極(ji)差(cha)，這(zhe)就是密(mi)封(feng)(feng)(feng)材(cai)料(liao)與(yu)液壓油的(de)(de)(de)相(xiang)容性(xing)。還有(you)(you)，各(ge)(ge)種(zhong)不(bu)同(tong)(tong)(tong)的(de)(de)(de)密(mi)封(feng)(feng)(feng)材(cai)料(liao)對你不(bu)同(tong)(tong)(tong)的(de)(de)(de)工作(zuo)條件表(biao)現(xian)出不(bu)同(tong)(tong)(tong)的(de)(de)(de)性(xing)能。有(you)(you)些(xie)(xie)耐(nai)(nai)熱，有(you)(you)些(xie)(xie)不(bu)耐(nai)(nai)熱;有(you)(you)些(xie)(xie)耐(nai)(nai)酸，有(you)(you)些(xie)(xie)耐(nai)(nai)堿(jian)，有(you)(you)些(xie)(xie)耐(nai)(nai)水(shui)，有(you)(you)些(xie)(xie)耐(nai)(nai)油;有(you)(you)些(xie)(xie)抗(kang)熱，有(you)(you)些(xie)(xie)耐(nai)(nai)低溫，有(you)(you)些(xie)(xie)耐(nai)(nai)高溫，等等。這(zhe)些(xie)(xie)因素在(zai)考慮密(mi)封(feng)(feng)(feng)件材(cai)料(liao)的(de)(de)(de)時候需(xu)注(zhu)意。