1、液壓(ya)密封件之形式選擇

　　在(zai)液壓(ya)系(xi)統中，常見的(de)密(mi)(mi)封(feng)形(xing)(xing)式有擠(ji)(ji)壓(ya)型O形(xing)(xing)密(mi)(mi)封(feng)圈、Y形(xing)(xing)圈、V形(xing)(xing)圈、U形(xing)(xing)圈唇形(xing)(xing)密(mi)(mi)封(feng)。唇形(xing)(xing)密(mi)(mi)封(feng)圈主(zhu)要用于往復(fu)動密(mi)(mi)封(feng)，與O形(xing)(xing)圈等擠(ji)(ji)壓(ya)密(mi)(mi)封(feng)相(xiang)比，往復(fu)動密(mi)(mi)封(feng)使用唇形(xing)(xing)密(mi)(mi)封(feng)圈具有更好的(de)綜(zong)合性能和更長的(de)使用壽命。

　　唇(chun)形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)緊力(li)(li)是隨介質壓(ya)(ya)力(li)(li)的(de)(de)(de)改變(bian)而變(bian)化的(de)(de)(de)，工(gong)作(zuo)(zuo)中始終應監控介質壓(ya)(ya)力(li)(li)的(de)(de)(de)變(bian)化，即能保證(zheng)足夠的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)緊力(li)(li)，又不(bu)至于產生(sheng)(sheng)過大(da)的(de)(de)(de)摩(mo)擦(ca)力(li)(li)，擠(ji)壓(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)主(zhu)要靠預壓(ya)(ya)緊力(li)(li)產生(sheng)(sheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)力(li)(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)接觸(chu)(chu)壓(ya)(ya)力(li)(li)預先給定，工(gong)作(zuo)(zuo)中不(bu)能根據介質壓(ya)(ya)力(li)(li)的(de)(de)(de)改變(bian)而變(bian)化。大(da)的(de)(de)(de)預壓(ya)(ya)力(li)(li)會使(shi)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)與密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)面接觸(chu)(chu)面積增大(da)，產生(sheng)(sheng)很大(da)的(de)(de)(de)摩(mo)擦(ca)阻力(li)(li)，過大(da)的(de)(de)(de)摩(mo)擦(ca)力(li)(li)會造成密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)的(de)(de)(de)破損，在低壓(ya)(ya)時造成啟動困難(nan)，或產生(sheng)(sheng)爬行現象，唇(chun)形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)可(ke)以通過唇(chun)部撐(cheng)開，變(bian)形補償(chang)小的(de)(de)(de)磨(mo)損量，保證(zheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)效果和(he)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壽命;而O形圈(quan)隨著摩(mo)擦(ca)余量的(de)(de)(de)減(jian)少，直接影(ying)響其密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)性。

　　2、液(ye)壓密封件之(zhi)材料選擇(ze)

　　密(mi)(mi)封(feng)(feng)(feng)件(jian)形(xing)式(shi)和結(jie)構現(xian)在(zai)一(yi)般已經定型，各密(mi)(mi)封(feng)(feng)(feng)件(jian)質(zhi)量區別主要(yao)在(zai)于制作材料(liao)上(shang)。密(mi)(mi)封(feng)(feng)(feng)材料(liao)主要(yao)使(shi)用(yong)(yong)橡膠和合成(cheng)樹脂(zhi)。由于各種材料(liao)性(xing)能特點(dian)不(bu)(bu)同(tong)(tong)(tong)，性(xing)能特點(dian)不(bu)(bu)同(tong)(tong)(tong)，用(yong)(yong)途也就有(you)(you)(you)所不(bu)(bu)同(tong)(tong)(tong)。選用(yong)(yong)時需(xu)根(gen)據不(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)和不(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)作出合適(shi)的(de)(de)(de)選擇。另外，某(mou)一(yi)材質(zhi)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)對被密(mi)(mi)封(feng)(feng)(feng)的(de)(de)(de)某(mou)一(yi)工作介質(zhi)(如礦物油(you)等(deng))表現(xian)較好的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)性(xing)能，而對另一(yi)介質(zhi)表現(xian)極差(cha)，這(zhe)就是密(mi)(mi)封(feng)(feng)(feng)材料(liao)與液壓油(you)的(de)(de)(de)相容性(xing)。還有(you)(you)(you)，各種不(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)材料(liao)對你(ni)不(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)工作條(tiao)件(jian)表現(xian)出不(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)性(xing)能。有(you)(you)(you)些(xie)(xie)(xie)耐熱(re)(re)，有(you)(you)(you)些(xie)(xie)(xie)不(bu)(bu)耐熱(re)(re);有(you)(you)(you)些(xie)(xie)(xie)耐酸(suan)，有(you)(you)(you)些(xie)(xie)(xie)耐堿，有(you)(you)(you)些(xie)(xie)(xie)耐水(shui)，有(you)(you)(you)些(xie)(xie)(xie)耐油(you);有(you)(you)(you)些(xie)(xie)(xie)抗熱(re)(re)，有(you)(you)(you)些(xie)(xie)(xie)耐低溫，有(you)(you)(you)些(xie)(xie)(xie)耐高溫，等(deng)等(deng)。這(zhe)些(xie)(xie)(xie)因素在(zai)考慮(lv)密(mi)(mi)封(feng)(feng)(feng)件(jian)材料(liao)的(de)(de)(de)時候需(xu)注(zhu)意。