1、液壓密封件之形式(shi)選擇

　　在液壓(ya)系統中(zhong)，常見的密(mi)(mi)(mi)封(feng)形(xing)式(shi)有擠(ji)壓(ya)型O形(xing)密(mi)(mi)(mi)封(feng)圈(quan)(quan)(quan)、Y形(xing)圈(quan)(quan)(quan)、V形(xing)圈(quan)(quan)(quan)、U形(xing)圈(quan)(quan)(quan)唇(chun)(chun)形(xing)密(mi)(mi)(mi)封(feng)。唇(chun)(chun)形(xing)密(mi)(mi)(mi)封(feng)圈(quan)(quan)(quan)主(zhu)要用(yong)于往復(fu)動密(mi)(mi)(mi)封(feng)，與O形(xing)圈(quan)(quan)(quan)等擠(ji)壓(ya)密(mi)(mi)(mi)封(feng)相(xiang)比，往復(fu)動密(mi)(mi)(mi)封(feng)使用(yong)唇(chun)(chun)形(xing)密(mi)(mi)(mi)封(feng)圈(quan)(quan)(quan)具有更好的綜合性能和更長的使用(yong)壽(shou)命。

　　唇形密(mi)封(feng)(feng)圈(quan)(quan)的密(mi)封(feng)(feng)壓(ya)(ya)(ya)緊力(li)(li)(li)(li)(li)(li)是隨(sui)介(jie)質壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)(li)的改(gai)變(bian)而變(bian)化的，工作(zuo)中始(shi)終(zhong)應監控(kong)介(jie)質壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)(li)的變(bian)化，即(ji)能(neng)保證足夠的密(mi)封(feng)(feng)壓(ya)(ya)(ya)緊力(li)(li)(li)(li)(li)(li)，又不(bu)至于產(chan)生過(guo)大的摩擦(ca)力(li)(li)(li)(li)(li)(li)，擠壓(ya)(ya)(ya)性密(mi)封(feng)(feng)主要靠預壓(ya)(ya)(ya)緊力(li)(li)(li)(li)(li)(li)產(chan)生密(mi)封(feng)(feng)力(li)(li)(li)(li)(li)(li)，密(mi)封(feng)(feng)圈(quan)(quan)接觸壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)(li)預先給定，工作(zuo)中不(bu)能(neng)根據(ju)介(jie)質壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)(li)的改(gai)變(bian)而變(bian)化。大的預壓(ya)(ya)(ya)力(li)(li)(li)(li)(li)(li)會使(shi)密(mi)封(feng)(feng)圈(quan)(quan)與(yu)密(mi)封(feng)(feng)面(mian)接觸面(mian)積(ji)增大，產(chan)生很大的摩擦(ca)阻力(li)(li)(li)(li)(li)(li)，過(guo)大的摩擦(ca)力(li)(li)(li)(li)(li)(li)會造成(cheng)密(mi)封(feng)(feng)圈(quan)(quan)的破損，在低(di)壓(ya)(ya)(ya)時造成(cheng)啟動困難，或(huo)產(chan)生爬(pa)行現象，唇形密(mi)封(feng)(feng)圈(quan)(quan)可(ke)以(yi)通(tong)過(guo)唇部撐開，變(bian)形補償(chang)小的磨損量(liang)，保證密(mi)封(feng)(feng)效果(guo)和(he)密(mi)封(feng)(feng)壽命(ming);而O形圈(quan)(quan)隨(sui)著摩擦(ca)余量(liang)的減少，直接影(ying)響其密(mi)封(feng)(feng)性。

　　2、液壓密封件之(zhi)材(cai)料選(xuan)擇

　　密(mi)(mi)(mi)封(feng)(feng)(feng)件(jian)形式和結構現(xian)在(zai)一般已(yi)經定型，各(ge)密(mi)(mi)(mi)封(feng)(feng)(feng)件(jian)質量區別主(zhu)要在(zai)于制作(zuo)(zuo)(zuo)材(cai)(cai)料上(shang)。密(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料主(zhu)要使用(yong)橡膠和合成樹脂。由于各(ge)種材(cai)(cai)料性(xing)能(neng)(neng)特(te)點不(bu)(bu)同(tong)(tong)(tong)，性(xing)能(neng)(neng)特(te)點不(bu)(bu)同(tong)(tong)(tong)，用(yong)途也(ye)就有所不(bu)(bu)同(tong)(tong)(tong)。選用(yong)時需根(gen)據不(bu)(bu)同(tong)(tong)(tong)的(de)(de)使用(yong)條件(jian)和不(bu)(bu)同(tong)(tong)(tong)的(de)(de)使用(yong)條件(jian)作(zuo)(zuo)(zuo)出合適(shi)的(de)(de)選擇。另外(wai)，某一材(cai)(cai)質的(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)對被密(mi)(mi)(mi)封(feng)(feng)(feng)的(de)(de)某一工(gong)作(zuo)(zuo)(zuo)介質(如礦(kuang)物油(you)等)表(biao)(biao)現(xian)較(jiao)好的(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)性(xing)能(neng)(neng)，而對另一介質表(biao)(biao)現(xian)極差，這就是密(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料與液壓油(you)的(de)(de)相容性(xing)。還有，各(ge)種不(bu)(bu)同(tong)(tong)(tong)的(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)材(cai)(cai)料對你(ni)不(bu)(bu)同(tong)(tong)(tong)的(de)(de)工(gong)作(zuo)(zuo)(zuo)條件(jian)表(biao)(biao)現(xian)出不(bu)(bu)同(tong)(tong)(tong)的(de)(de)性(xing)能(neng)(neng)。有些(xie)耐(nai)熱，有些(xie)不(bu)(bu)耐(nai)熱;有些(xie)耐(nai)酸，有些(xie)耐(nai)堿，有些(xie)耐(nai)水(shui)，有些(xie)耐(nai)油(you);有些(xie)抗熱，有些(xie)耐(nai)低(di)溫，有些(xie)耐(nai)高(gao)溫，等等。這些(xie)因素在(zai)考(kao)慮密(mi)(mi)(mi)封(feng)(feng)(feng)件(jian)材(cai)(cai)料的(de)(de)時候需注意。