1、液(ye)壓密封件之形式選擇(ze)

　　在液(ye)壓系統中(zhong)，常見(jian)的(de)密封(feng)形(xing)(xing)(xing)(xing)(xing)式有(you)擠(ji)(ji)壓型O形(xing)(xing)(xing)(xing)(xing)密封(feng)圈(quan)(quan)(quan)、Y形(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)、V形(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)、U形(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)唇(chun)形(xing)(xing)(xing)(xing)(xing)密封(feng)。唇(chun)形(xing)(xing)(xing)(xing)(xing)密封(feng)圈(quan)(quan)(quan)主要用于往復(fu)動密封(feng)，與O形(xing)(xing)(xing)(xing)(xing)圈(quan)(quan)(quan)等擠(ji)(ji)壓密封(feng)相比，往復(fu)動密封(feng)使用唇(chun)形(xing)(xing)(xing)(xing)(xing)密封(feng)圈(quan)(quan)(quan)具有(you)更好(hao)的(de)綜合性能(neng)和更長(chang)的(de)使用壽命。

　　唇形密(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)壓(ya)緊力(li)(li)是隨(sui)介(jie)質(zhi)壓(ya)力(li)(li)的(de)(de)(de)改(gai)變(bian)(bian)而變(bian)(bian)化(hua)(hua)的(de)(de)(de)，工(gong)作中(zhong)始終(zhong)應監控介(jie)質(zhi)壓(ya)力(li)(li)的(de)(de)(de)變(bian)(bian)化(hua)(hua)，即能保證(zheng)足夠的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)壓(ya)緊力(li)(li)，又不至(zhi)于產(chan)(chan)生(sheng)(sheng)過(guo)(guo)大(da)(da)(da)的(de)(de)(de)摩(mo)(mo)擦(ca)力(li)(li)，擠壓(ya)性密(mi)(mi)封(feng)(feng)(feng)主(zhu)要靠(kao)預(yu)壓(ya)緊力(li)(li)產(chan)(chan)生(sheng)(sheng)密(mi)(mi)封(feng)(feng)(feng)力(li)(li)，密(mi)(mi)封(feng)(feng)(feng)圈(quan)接(jie)觸壓(ya)力(li)(li)預(yu)先給(gei)定(ding)，工(gong)作中(zhong)不能根據介(jie)質(zhi)壓(ya)力(li)(li)的(de)(de)(de)改(gai)變(bian)(bian)而變(bian)(bian)化(hua)(hua)。大(da)(da)(da)的(de)(de)(de)預(yu)壓(ya)力(li)(li)會使密(mi)(mi)封(feng)(feng)(feng)圈(quan)與密(mi)(mi)封(feng)(feng)(feng)面(mian)接(jie)觸面(mian)積增大(da)(da)(da)，產(chan)(chan)生(sheng)(sheng)很(hen)大(da)(da)(da)的(de)(de)(de)摩(mo)(mo)擦(ca)阻力(li)(li)，過(guo)(guo)大(da)(da)(da)的(de)(de)(de)摩(mo)(mo)擦(ca)力(li)(li)會造成(cheng)密(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)破損，在低壓(ya)時造成(cheng)啟動困難，或(huo)產(chan)(chan)生(sheng)(sheng)爬行現象，唇形密(mi)(mi)封(feng)(feng)(feng)圈(quan)可以通過(guo)(guo)唇部撐(cheng)開(kai)，變(bian)(bian)形補償小的(de)(de)(de)磨(mo)損量，保證(zheng)密(mi)(mi)封(feng)(feng)(feng)效果和密(mi)(mi)封(feng)(feng)(feng)壽命;而O形圈(quan)隨(sui)著摩(mo)(mo)擦(ca)余量的(de)(de)(de)減(jian)少(shao)，直(zhi)接(jie)影響(xiang)其密(mi)(mi)封(feng)(feng)(feng)性。

　　2、液壓密(mi)封件之材料選(xuan)擇

　　密封(feng)(feng)(feng)(feng)件形式和結構現(xian)在(zai)(zai)一(yi)般已經定型，各(ge)密封(feng)(feng)(feng)(feng)件質(zhi)量(liang)區別主要在(zai)(zai)于(yu)制作材料上。密封(feng)(feng)(feng)(feng)材料主要使用(yong)(yong)橡膠和合成樹脂(zhi)。由于(yu)各(ge)種材料性能(neng)特(te)點(dian)不(bu)(bu)(bu)(bu)(bu)同(tong)，性能(neng)特(te)點(dian)不(bu)(bu)(bu)(bu)(bu)同(tong)，用(yong)(yong)途也就有(you)(you)所(suo)不(bu)(bu)(bu)(bu)(bu)同(tong)。選用(yong)(yong)時(shi)需根據不(bu)(bu)(bu)(bu)(bu)同(tong)的使用(yong)(yong)條(tiao)件和不(bu)(bu)(bu)(bu)(bu)同(tong)的使用(yong)(yong)條(tiao)件作出合適的選擇。另外(wai)，某一(yi)材質(zhi)的密封(feng)(feng)(feng)(feng)對(dui)被密封(feng)(feng)(feng)(feng)的某一(yi)工作介(jie)質(zhi)(如礦物油等)表(biao)(biao)現(xian)較(jiao)好(hao)的密封(feng)(feng)(feng)(feng)性能(neng)，而(er)對(dui)另一(yi)介(jie)質(zhi)表(biao)(biao)現(xian)極差(cha)，這就是密封(feng)(feng)(feng)(feng)材料與液壓(ya)油的相(xiang)容性。還有(you)(you)，各(ge)種不(bu)(bu)(bu)(bu)(bu)同(tong)的密封(feng)(feng)(feng)(feng)材料對(dui)你(ni)不(bu)(bu)(bu)(bu)(bu)同(tong)的工作條(tiao)件表(biao)(biao)現(xian)出不(bu)(bu)(bu)(bu)(bu)同(tong)的性能(neng)。有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)熱，有(you)(you)些(xie)(xie)(xie)不(bu)(bu)(bu)(bu)(bu)耐(nai)(nai)熱;有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)酸，有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)堿(jian)，有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)水，有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)油;有(you)(you)些(xie)(xie)(xie)抗(kang)熱，有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)低(di)溫(wen)，有(you)(you)些(xie)(xie)(xie)耐(nai)(nai)高(gao)溫(wen)，等等。這些(xie)(xie)(xie)因素在(zai)(zai)考慮(lv)密封(feng)(feng)(feng)(feng)件材料的時(shi)候需注意。