1、液壓密封件之形式選擇

　　在液壓(ya)系統(tong)中，常見的(de)密(mi)封(feng)形(xing)式有擠(ji)壓(ya)型O形(xing)密(mi)封(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)封(feng)。唇形(xing)密(mi)封(feng)圈(quan)(quan)主要用(yong)(yong)于往復動密(mi)封(feng)，與O形(xing)圈(quan)(quan)等擠(ji)壓(ya)密(mi)封(feng)相比，往復動密(mi)封(feng)使用(yong)(yong)唇形(xing)密(mi)封(feng)圈(quan)(quan)具有更好(hao)的(de)綜合性(xing)能和更長(chang)的(de)使用(yong)(yong)壽命。

　　唇(chun)形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)是(shi)隨介質(zhi)壓(ya)(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)改(gai)變(bian)(bian)而(er)(er)變(bian)(bian)化(hua)的(de)(de)(de)(de)(de)，工(gong)作中始終應監(jian)控介質(zhi)壓(ya)(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)變(bian)(bian)化(hua)，即能(neng)保證(zheng)足夠(gou)的(de)(de)(de)(de)(de)密(mi)(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊(jin)力(li)，又不至于產(chan)生(sheng)(sheng)過(guo)大(da)的(de)(de)(de)(de)(de)摩擦(ca)力(li)，擠壓(ya)(ya)(ya)(ya)性密(mi)(mi)(mi)封(feng)(feng)(feng)主要靠預壓(ya)(ya)(ya)(ya)緊(jin)力(li)產(chan)生(sheng)(sheng)密(mi)(mi)(mi)封(feng)(feng)(feng)力(li)，密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)接觸壓(ya)(ya)(ya)(ya)力(li)預先給定，工(gong)作中不能(neng)根據介質(zhi)壓(ya)(ya)(ya)(ya)力(li)的(de)(de)(de)(de)(de)改(gai)變(bian)(bian)而(er)(er)變(bian)(bian)化(hua)。大(da)的(de)(de)(de)(de)(de)預壓(ya)(ya)(ya)(ya)力(li)會(hui)使密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)與密(mi)(mi)(mi)封(feng)(feng)(feng)面接觸面積增大(da)，產(chan)生(sheng)(sheng)很(hen)大(da)的(de)(de)(de)(de)(de)摩擦(ca)阻力(li)，過(guo)大(da)的(de)(de)(de)(de)(de)摩擦(ca)力(li)會(hui)造成(cheng)密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)(de)(de)破損(sun)，在低壓(ya)(ya)(ya)(ya)時(shi)造成(cheng)啟(qi)動困難，或產(chan)生(sheng)(sheng)爬行(xing)現象，唇(chun)形(xing)密(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)可以通過(guo)唇(chun)部撐開，變(bian)(bian)形(xing)補償小的(de)(de)(de)(de)(de)磨損(sun)量(liang)，保證(zheng)密(mi)(mi)(mi)封(feng)(feng)(feng)效果和密(mi)(mi)(mi)封(feng)(feng)(feng)壽命;而(er)(er)O形(xing)圈(quan)隨著摩擦(ca)余量(liang)的(de)(de)(de)(de)(de)減少，直接影(ying)響其(qi)密(mi)(mi)(mi)封(feng)(feng)(feng)性。

　　2、液(ye)壓密(mi)封件之材料選擇

　　密(mi)(mi)封(feng)(feng)件(jian)(jian)形(xing)式(shi)和(he)(he)結構現在一(yi)(yi)般已經定型，各(ge)密(mi)(mi)封(feng)(feng)件(jian)(jian)質(zhi)(zhi)量區別(bie)主要在于制(zhi)作(zuo)材料(liao)(liao)(liao)上。密(mi)(mi)封(feng)(feng)材料(liao)(liao)(liao)主要使(shi)(shi)用橡膠和(he)(he)合成樹脂。由于各(ge)種材料(liao)(liao)(liao)性(xing)(xing)能(neng)(neng)特(te)點不(bu)(bu)(bu)同(tong)(tong)，性(xing)(xing)能(neng)(neng)特(te)點不(bu)(bu)(bu)同(tong)(tong)，用途也(ye)就(jiu)有(you)(you)(you)(you)(you)(you)所不(bu)(bu)(bu)同(tong)(tong)。選(xuan)用時需根(gen)據不(bu)(bu)(bu)同(tong)(tong)的(de)(de)使(shi)(shi)用條(tiao)件(jian)(jian)和(he)(he)不(bu)(bu)(bu)同(tong)(tong)的(de)(de)使(shi)(shi)用條(tiao)件(jian)(jian)作(zuo)出(chu)合適的(de)(de)選(xuan)擇。另外，某一(yi)(yi)材質(zhi)(zhi)的(de)(de)密(mi)(mi)封(feng)(feng)對被密(mi)(mi)封(feng)(feng)的(de)(de)某一(yi)(yi)工作(zuo)介質(zhi)(zhi)(如礦物油(you)(you)(you)等(deng))表現較好的(de)(de)密(mi)(mi)封(feng)(feng)性(xing)(xing)能(neng)(neng)，而(er)對另一(yi)(yi)介質(zhi)(zhi)表現極差，這(zhe)就(jiu)是(shi)密(mi)(mi)封(feng)(feng)材料(liao)(liao)(liao)與液(ye)壓(ya)油(you)(you)(you)的(de)(de)相(xiang)容性(xing)(xing)。還有(you)(you)(you)(you)(you)(you)，各(ge)種不(bu)(bu)(bu)同(tong)(tong)的(de)(de)密(mi)(mi)封(feng)(feng)材料(liao)(liao)(liao)對你不(bu)(bu)(bu)同(tong)(tong)的(de)(de)工作(zuo)條(tiao)件(jian)(jian)表現出(chu)不(bu)(bu)(bu)同(tong)(tong)的(de)(de)性(xing)(xing)能(neng)(neng)。有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)熱，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)不(bu)(bu)(bu)耐(nai)(nai)熱;有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)酸，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)堿，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)水(shui)，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)油(you)(you)(you);有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)抗熱，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)低(di)溫，有(you)(you)(you)(you)(you)(you)些(xie)(xie)(xie)(xie)耐(nai)(nai)高溫，等(deng)等(deng)。這(zhe)些(xie)(xie)(xie)(xie)因(yin)素在考慮密(mi)(mi)封(feng)(feng)件(jian)(jian)材料(liao)(liao)(liao)的(de)(de)時候需注意。