1、液壓密封件之形式選擇

　　在液壓(ya)系統(tong)中，常見的密(mi)封形(xing)(xing)(xing)(xing)(xing)(xing)式有(you)擠壓(ya)型O形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)封圈(quan)、Y形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)、V形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)、U形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)唇形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)封。唇形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)封圈(quan)主要用(yong)于往(wang)復(fu)動(dong)密(mi)封，與O形(xing)(xing)(xing)(xing)(xing)(xing)圈(quan)等擠壓(ya)密(mi)封相比，往(wang)復(fu)動(dong)密(mi)封使(shi)用(yong)唇形(xing)(xing)(xing)(xing)(xing)(xing)密(mi)封圈(quan)具有(you)更好的綜合(he)性(xing)能(neng)和更長(chang)的使(shi)用(yong)壽命(ming)。

　　唇(chun)(chun)形密(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)密(mi)封(feng)(feng)(feng)壓(ya)緊力(li)(li)是隨(sui)介質壓(ya)力(li)(li)的(de)(de)(de)改(gai)變而變化(hua)的(de)(de)(de)，工作中始終(zhong)應監控介質壓(ya)力(li)(li)的(de)(de)(de)變化(hua)，即能保證(zheng)足夠的(de)(de)(de)密(mi)封(feng)(feng)(feng)壓(ya)緊力(li)(li)，又不至(zhi)于產(chan)(chan)生(sheng)過大(da)的(de)(de)(de)摩(mo)(mo)擦(ca)力(li)(li)，擠(ji)壓(ya)性密(mi)封(feng)(feng)(feng)主(zhu)要靠預壓(ya)緊力(li)(li)產(chan)(chan)生(sheng)密(mi)封(feng)(feng)(feng)力(li)(li)，密(mi)封(feng)(feng)(feng)圈(quan)接(jie)觸壓(ya)力(li)(li)預先給定(ding)，工作中不能根據介質壓(ya)力(li)(li)的(de)(de)(de)改(gai)變而變化(hua)。大(da)的(de)(de)(de)預壓(ya)力(li)(li)會(hui)使密(mi)封(feng)(feng)(feng)圈(quan)與密(mi)封(feng)(feng)(feng)面接(jie)觸面積增大(da)，產(chan)(chan)生(sheng)很大(da)的(de)(de)(de)摩(mo)(mo)擦(ca)阻(zu)力(li)(li)，過大(da)的(de)(de)(de)摩(mo)(mo)擦(ca)力(li)(li)會(hui)造(zao)成密(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)破損，在低壓(ya)時造(zao)成啟動困難，或產(chan)(chan)生(sheng)爬行現象，唇(chun)(chun)形密(mi)封(feng)(feng)(feng)圈(quan)可以通過唇(chun)(chun)部(bu)撐開(kai)，變形補(bu)償小(xiao)的(de)(de)(de)磨損量，保證(zheng)密(mi)封(feng)(feng)(feng)效果和密(mi)封(feng)(feng)(feng)壽(shou)命;而O形圈(quan)隨(sui)著摩(mo)(mo)擦(ca)余量的(de)(de)(de)減少，直接(jie)影響其密(mi)封(feng)(feng)(feng)性。

　　2、液(ye)壓密封(feng)件(jian)之材料選擇

　　密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)(jian)形(xing)式和(he)結構現(xian)(xian)在(zai)一(yi)般已(yi)經定(ding)型，各密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)(jian)質(zhi)(zhi)(zhi)量區別主要在(zai)于制作(zuo)(zuo)材(cai)(cai)(cai)料上。密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料主要使(shi)用(yong)(yong)橡膠(jiao)和(he)合成樹脂。由于各種材(cai)(cai)(cai)料性(xing)(xing)能特(te)點(dian)不(bu)同(tong)(tong)(tong)，性(xing)(xing)能特(te)點(dian)不(bu)同(tong)(tong)(tong)，用(yong)(yong)途也就有(you)(you)(you)所(suo)不(bu)同(tong)(tong)(tong)。選(xuan)用(yong)(yong)時需(xu)根(gen)據(ju)不(bu)同(tong)(tong)(tong)的(de)(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)(jian)和(he)不(bu)同(tong)(tong)(tong)的(de)(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)(jian)作(zuo)(zuo)出合適的(de)(de)(de)選(xuan)擇。另外，某一(yi)材(cai)(cai)(cai)質(zhi)(zhi)(zhi)的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)對被密(mi)(mi)(mi)(mi)封(feng)(feng)的(de)(de)(de)某一(yi)工作(zuo)(zuo)介質(zhi)(zhi)(zhi)(如礦物油(you)(you)等)表(biao)現(xian)(xian)較好的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)性(xing)(xing)能，而對另一(yi)介質(zhi)(zhi)(zhi)表(biao)現(xian)(xian)極(ji)差(cha)，這就是(shi)密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料與(yu)液壓油(you)(you)的(de)(de)(de)相(xiang)容性(xing)(xing)。還有(you)(you)(you)，各種不(bu)同(tong)(tong)(tong)的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料對你不(bu)同(tong)(tong)(tong)的(de)(de)(de)工作(zuo)(zuo)條(tiao)件(jian)(jian)表(biao)現(xian)(xian)出不(bu)同(tong)(tong)(tong)的(de)(de)(de)性(xing)(xing)能。有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)熱，有(you)(you)(you)些(xie)(xie)不(bu)耐(nai)(nai)(nai)(nai)熱;有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)酸，有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)堿，有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)水，有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)油(you)(you);有(you)(you)(you)些(xie)(xie)抗(kang)熱，有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)低溫，有(you)(you)(you)些(xie)(xie)耐(nai)(nai)(nai)(nai)高溫，等等。這些(xie)(xie)因素在(zai)考慮密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)(jian)材(cai)(cai)(cai)料的(de)(de)(de)時候需(xu)注(zhu)意。