1、液壓(ya)密封(feng)件之(zhi)形式(shi)選擇

　　在(zai)液壓(ya)系統中，常見的密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)形(xing)式有擠(ji)(ji)壓(ya)型(xing)O形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)、Y形(xing)圈(quan)(quan)、V形(xing)圈(quan)(quan)、U形(xing)圈(quan)(quan)唇形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)。唇形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)主要用(yong)(yong)于往復動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)，與O形(xing)圈(quan)(quan)等擠(ji)(ji)壓(ya)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)相比，往復動(dong)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)使用(yong)(yong)唇形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)(quan)具有更好(hao)的綜合(he)性(xing)能和更長的使用(yong)(yong)壽命。

　　唇形密(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊(jin)力(li)是隨(sui)介質壓(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)(de)改變(bian)(bian)而變(bian)(bian)化的(de)(de)(de)(de)(de)(de)，工(gong)(gong)作(zuo)中(zhong)始終(zhong)應監(jian)控(kong)介質壓(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)(de)變(bian)(bian)化，即能(neng)保證(zheng)足夠的(de)(de)(de)(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)緊(jin)力(li)，又不至(zhi)于產(chan)生過(guo)大(da)的(de)(de)(de)(de)(de)(de)摩(mo)擦(ca)力(li)，擠壓(ya)(ya)(ya)性密(mi)(mi)封(feng)(feng)(feng)(feng)主要靠(kao)預壓(ya)(ya)(ya)緊(jin)力(li)產(chan)生密(mi)(mi)封(feng)(feng)(feng)(feng)力(li)，密(mi)(mi)封(feng)(feng)(feng)(feng)圈接(jie)觸壓(ya)(ya)(ya)力(li)預先(xian)給(gei)定，工(gong)(gong)作(zuo)中(zhong)不能(neng)根據介質壓(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)(de)改變(bian)(bian)而變(bian)(bian)化。大(da)的(de)(de)(de)(de)(de)(de)預壓(ya)(ya)(ya)力(li)會使密(mi)(mi)封(feng)(feng)(feng)(feng)圈與密(mi)(mi)封(feng)(feng)(feng)(feng)面接(jie)觸面積(ji)增大(da)，產(chan)生很大(da)的(de)(de)(de)(de)(de)(de)摩(mo)擦(ca)阻(zu)力(li)，過(guo)大(da)的(de)(de)(de)(de)(de)(de)摩(mo)擦(ca)力(li)會造成(cheng)密(mi)(mi)封(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)(de)(de)破損(sun)，在低壓(ya)(ya)(ya)時(shi)造成(cheng)啟動困難，或產(chan)生爬行現象，唇形密(mi)(mi)封(feng)(feng)(feng)(feng)圈可以通過(guo)唇部撐開，變(bian)(bian)形補(bu)償小的(de)(de)(de)(de)(de)(de)磨損(sun)量，保證(zheng)密(mi)(mi)封(feng)(feng)(feng)(feng)效果和密(mi)(mi)封(feng)(feng)(feng)(feng)壽命;而O形圈隨(sui)著摩(mo)擦(ca)余量的(de)(de)(de)(de)(de)(de)減少，直接(jie)影響其密(mi)(mi)封(feng)(feng)(feng)(feng)性。

　　2、液壓密封(feng)件(jian)之材料選(xuan)擇(ze)

　　密(mi)封(feng)(feng)件形式和(he)結構現(xian)(xian)在一般已經定型，各(ge)密(mi)封(feng)(feng)件質(zhi)量區別(bie)主要在于(yu)制作(zuo)(zuo)材(cai)(cai)料(liao)(liao)上。密(mi)封(feng)(feng)材(cai)(cai)料(liao)(liao)主要使用(yong)橡膠和(he)合成樹脂。由于(yu)各(ge)種材(cai)(cai)料(liao)(liao)性(xing)(xing)能特(te)點不(bu)(bu)同(tong)(tong)，性(xing)(xing)能特(te)點不(bu)(bu)同(tong)(tong)，用(yong)途也就有(you)(you)(you)(you)所不(bu)(bu)同(tong)(tong)。選用(yong)時(shi)需(xu)(xu)根據不(bu)(bu)同(tong)(tong)的(de)使用(yong)條件和(he)不(bu)(bu)同(tong)(tong)的(de)使用(yong)條件作(zuo)(zuo)出合適的(de)選擇。另外(wai)，某(mou)一材(cai)(cai)質(zhi)的(de)密(mi)封(feng)(feng)對被密(mi)封(feng)(feng)的(de)某(mou)一工作(zuo)(zuo)介(jie)質(zhi)(如(ru)礦物油(you)等(deng))表(biao)(biao)現(xian)(xian)較(jiao)好的(de)密(mi)封(feng)(feng)性(xing)(xing)能，而對另一介(jie)質(zhi)表(biao)(biao)現(xian)(xian)極(ji)差(cha)，這就是密(mi)封(feng)(feng)材(cai)(cai)料(liao)(liao)與液壓油(you)的(de)相(xiang)容性(xing)(xing)。還(huan)有(you)(you)(you)(you)，各(ge)種不(bu)(bu)同(tong)(tong)的(de)密(mi)封(feng)(feng)材(cai)(cai)料(liao)(liao)對你(ni)不(bu)(bu)同(tong)(tong)的(de)工作(zuo)(zuo)條件表(biao)(biao)現(xian)(xian)出不(bu)(bu)同(tong)(tong)的(de)性(xing)(xing)能。有(you)(you)(you)(you)些(xie)(xie)耐(nai)熱，有(you)(you)(you)(you)些(xie)(xie)不(bu)(bu)耐(nai)熱;有(you)(you)(you)(you)些(xie)(xie)耐(nai)酸，有(you)(you)(you)(you)些(xie)(xie)耐(nai)堿(jian)，有(you)(you)(you)(you)些(xie)(xie)耐(nai)水，有(you)(you)(you)(you)些(xie)(xie)耐(nai)油(you);有(you)(you)(you)(you)些(xie)(xie)抗熱，有(you)(you)(you)(you)些(xie)(xie)耐(nai)低溫(wen)，有(you)(you)(you)(you)些(xie)(xie)耐(nai)高溫(wen)，等(deng)等(deng)。這些(xie)(xie)因素(su)在考(kao)慮(lv)密(mi)封(feng)(feng)件材(cai)(cai)料(liao)(liao)的(de)時(shi)候(hou)需(xu)(xu)注意。