1、液(ye)壓密封件之形式選擇

　　在液壓系統中，常(chang)見的密(mi)封(feng)(feng)(feng)形(xing)(xing)(xing)(xing)式有(you)擠壓型O形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)(feng)圈(quan)、Y形(xing)(xing)(xing)(xing)圈(quan)、V形(xing)(xing)(xing)(xing)圈(quan)、U形(xing)(xing)(xing)(xing)圈(quan)唇形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)(feng)。唇形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)(feng)圈(quan)主要用于往復(fu)動密(mi)封(feng)(feng)(feng)，與(yu)O形(xing)(xing)(xing)(xing)圈(quan)等擠壓密(mi)封(feng)(feng)(feng)相比，往復(fu)動密(mi)封(feng)(feng)(feng)使用唇形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)(feng)圈(quan)具有(you)更好的綜合(he)性能和更長的使用壽命。

　　唇(chun)形(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)的密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)是隨介質壓(ya)(ya)(ya)(ya)力(li)(li)的改變而變化(hua)的，工作中始(shi)終應監控介質壓(ya)(ya)(ya)(ya)力(li)(li)的變化(hua)，即(ji)能保證足夠的密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)，又(you)不至于產(chan)生過(guo)大(da)(da)的摩(mo)擦(ca)(ca)力(li)(li)，擠壓(ya)(ya)(ya)(ya)性密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)主要靠預(yu)壓(ya)(ya)(ya)(ya)緊(jin)力(li)(li)產(chan)生密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)力(li)(li)，密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)接(jie)觸壓(ya)(ya)(ya)(ya)力(li)(li)預(yu)先給定，工作中不能根(gen)據介質壓(ya)(ya)(ya)(ya)力(li)(li)的改變而變化(hua)。大(da)(da)的預(yu)壓(ya)(ya)(ya)(ya)力(li)(li)會(hui)使密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)與(yu)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)面接(jie)觸面積增大(da)(da)，產(chan)生很大(da)(da)的摩(mo)擦(ca)(ca)阻力(li)(li)，過(guo)大(da)(da)的摩(mo)擦(ca)(ca)力(li)(li)會(hui)造成(cheng)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)的破損，在低壓(ya)(ya)(ya)(ya)時造成(cheng)啟動困難，或產(chan)生爬行現象，唇(chun)形(xing)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)可(ke)以通過(guo)唇(chun)部撐(cheng)開，變形(xing)補償(chang)小的磨損量，保證密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)效果和密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壽命;而O形(xing)圈(quan)隨著摩(mo)擦(ca)(ca)余量的減少，直接(jie)影響其密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)性。

　　2、液壓密封(feng)件之材(cai)料選擇

　　密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)件形式和結構現(xian)在一(yi)般已(yi)經定型，各(ge)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)件質量(liang)區別主要(yao)在于制作(zuo)(zuo)材(cai)(cai)料(liao)上。密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料(liao)主要(yao)使(shi)用(yong)橡膠和合(he)成(cheng)樹脂。由于各(ge)種(zhong)材(cai)(cai)料(liao)性(xing)能特(te)點不(bu)(bu)同(tong)(tong)(tong)，性(xing)能特(te)點不(bu)(bu)同(tong)(tong)(tong)，用(yong)途也(ye)就(jiu)有(you)(you)(you)所不(bu)(bu)同(tong)(tong)(tong)。選(xuan)用(yong)時需(xu)根據不(bu)(bu)同(tong)(tong)(tong)的(de)(de)使(shi)用(yong)條(tiao)件和不(bu)(bu)同(tong)(tong)(tong)的(de)(de)使(shi)用(yong)條(tiao)件作(zuo)(zuo)出(chu)合(he)適的(de)(de)選(xuan)擇。另(ling)外(wai)，某一(yi)材(cai)(cai)質的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)對(dui)被(bei)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)的(de)(de)某一(yi)工(gong)作(zuo)(zuo)介質(如礦(kuang)物油(you)等(deng))表(biao)現(xian)較好的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)性(xing)能，而對(dui)另(ling)一(yi)介質表(biao)現(xian)極差，這就(jiu)是密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料(liao)與(yu)液壓油(you)的(de)(de)相(xiang)容性(xing)。還有(you)(you)(you)，各(ge)種(zhong)不(bu)(bu)同(tong)(tong)(tong)的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料(liao)對(dui)你不(bu)(bu)同(tong)(tong)(tong)的(de)(de)工(gong)作(zuo)(zuo)條(tiao)件表(biao)現(xian)出(chu)不(bu)(bu)同(tong)(tong)(tong)的(de)(de)性(xing)能。有(you)(you)(you)些(xie)耐(nai)熱，有(you)(you)(you)些(xie)不(bu)(bu)耐(nai)熱;有(you)(you)(you)些(xie)耐(nai)酸，有(you)(you)(you)些(xie)耐(nai)堿，有(you)(you)(you)些(xie)耐(nai)水，有(you)(you)(you)些(xie)耐(nai)油(you);有(you)(you)(you)些(xie)抗熱，有(you)(you)(you)些(xie)耐(nai)低溫(wen)，有(you)(you)(you)些(xie)耐(nai)高溫(wen)，等(deng)等(deng)。這些(xie)因(yin)素在考慮(lv)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)件材(cai)(cai)料(liao)的(de)(de)時候需(xu)注(zhu)意。