1、液(ye)壓密封(feng)件(jian)之形(xing)式選(xuan)擇

　　在液壓(ya)系統中，常見的密(mi)封(feng)形(xing)(xing)(xing)式有擠(ji)壓(ya)型O形(xing)(xing)(xing)密(mi)封(feng)圈(quan)、Y形(xing)(xing)(xing)圈(quan)、V形(xing)(xing)(xing)圈(quan)、U形(xing)(xing)(xing)圈(quan)唇(chun)形(xing)(xing)(xing)密(mi)封(feng)。唇(chun)形(xing)(xing)(xing)密(mi)封(feng)圈(quan)主(zhu)要用于往復(fu)動密(mi)封(feng)，與(yu)O形(xing)(xing)(xing)圈(quan)等擠(ji)壓(ya)密(mi)封(feng)相比，往復(fu)動密(mi)封(feng)使用唇(chun)形(xing)(xing)(xing)密(mi)封(feng)圈(quan)具有更(geng)(geng)好的綜合性能和更(geng)(geng)長(chang)的使用壽命(ming)。

　　唇形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)緊(jin)力(li)(li)是隨(sui)介質(zhi)壓(ya)(ya)力(li)(li)的(de)(de)(de)(de)(de)(de)改變而(er)變化(hua)的(de)(de)(de)(de)(de)(de)，工(gong)作(zuo)中(zhong)始(shi)終(zhong)應(ying)監控介質(zhi)壓(ya)(ya)力(li)(li)的(de)(de)(de)(de)(de)(de)變化(hua)，即能保證(zheng)(zheng)足夠(gou)的(de)(de)(de)(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)緊(jin)力(li)(li)，又不至于產(chan)生(sheng)(sheng)過(guo)(guo)大(da)的(de)(de)(de)(de)(de)(de)摩擦(ca)(ca)力(li)(li)，擠壓(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)主(zhu)要靠預(yu)壓(ya)(ya)緊(jin)力(li)(li)產(chan)生(sheng)(sheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)力(li)(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈接觸壓(ya)(ya)力(li)(li)預(yu)先給定，工(gong)作(zuo)中(zhong)不能根(gen)據介質(zhi)壓(ya)(ya)力(li)(li)的(de)(de)(de)(de)(de)(de)改變而(er)變化(hua)。大(da)的(de)(de)(de)(de)(de)(de)預(yu)壓(ya)(ya)力(li)(li)會(hui)使密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈與密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)面接觸面積增(zeng)大(da)，產(chan)生(sheng)(sheng)很(hen)大(da)的(de)(de)(de)(de)(de)(de)摩擦(ca)(ca)阻力(li)(li)，過(guo)(guo)大(da)的(de)(de)(de)(de)(de)(de)摩擦(ca)(ca)力(li)(li)會(hui)造(zao)成密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)(de)(de)破損，在低壓(ya)(ya)時造(zao)成啟動困難，或產(chan)生(sheng)(sheng)爬行現象，唇形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈可以通過(guo)(guo)唇部撐開，變形補償小(xiao)的(de)(de)(de)(de)(de)(de)磨損量，保證(zheng)(zheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)效(xiao)果(guo)和密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壽命;而(er)O形圈隨(sui)著摩擦(ca)(ca)余(yu)量的(de)(de)(de)(de)(de)(de)減(jian)少，直接影響其密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)性。

　　2、液壓密封件(jian)之材料選擇

　　密封(feng)(feng)件(jian)形式和(he)結構現在一般已(yi)經(jing)定型，各密封(feng)(feng)件(jian)質(zhi)(zhi)量區別(bie)主要在于(yu)制作材(cai)(cai)(cai)料(liao)上。密封(feng)(feng)材(cai)(cai)(cai)料(liao)主要使(shi)(shi)(shi)用(yong)(yong)橡(xiang)膠(jiao)和(he)合(he)成樹脂。由(you)于(yu)各種材(cai)(cai)(cai)料(liao)性(xing)(xing)能特點不(bu)(bu)同(tong)(tong)，性(xing)(xing)能特點不(bu)(bu)同(tong)(tong)，用(yong)(yong)途也就(jiu)有(you)(you)所不(bu)(bu)同(tong)(tong)。選用(yong)(yong)時需根據不(bu)(bu)同(tong)(tong)的(de)使(shi)(shi)(shi)用(yong)(yong)條(tiao)件(jian)和(he)不(bu)(bu)同(tong)(tong)的(de)使(shi)(shi)(shi)用(yong)(yong)條(tiao)件(jian)作出合(he)適的(de)選擇。另(ling)外，某(mou)一材(cai)(cai)(cai)質(zhi)(zhi)的(de)密封(feng)(feng)對被密封(feng)(feng)的(de)某(mou)一工作介質(zhi)(zhi)(如礦物油(you)等)表現較好的(de)密封(feng)(feng)性(xing)(xing)能，而對另(ling)一介質(zhi)(zhi)表現極(ji)差(cha)，這就(jiu)是密封(feng)(feng)材(cai)(cai)(cai)料(liao)與液壓油(you)的(de)相容(rong)性(xing)(xing)。還有(you)(you)，各種不(bu)(bu)同(tong)(tong)的(de)密封(feng)(feng)材(cai)(cai)(cai)料(liao)對你不(bu)(bu)同(tong)(tong)的(de)工作條(tiao)件(jian)表現出不(bu)(bu)同(tong)(tong)的(de)性(xing)(xing)能。有(you)(you)些(xie)耐(nai)(nai)熱(re)，有(you)(you)些(xie)不(bu)(bu)耐(nai)(nai)熱(re);有(you)(you)些(xie)耐(nai)(nai)酸，有(you)(you)些(xie)耐(nai)(nai)堿，有(you)(you)些(xie)耐(nai)(nai)水，有(you)(you)些(xie)耐(nai)(nai)油(you);有(you)(you)些(xie)抗熱(re)，有(you)(you)些(xie)耐(nai)(nai)低(di)溫，有(you)(you)些(xie)耐(nai)(nai)高溫，等等。這些(xie)因素在考慮密封(feng)(feng)件(jian)材(cai)(cai)(cai)料(liao)的(de)時候(hou)需注(zhu)意。