1、液壓密封件之形式選擇

　　在液(ye)壓系(xi)統中(zhong)，常見的(de)密(mi)封(feng)(feng)形(xing)(xing)(xing)(xing)式(shi)有擠壓型O形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)圈(quan)(quan)、Y形(xing)(xing)(xing)(xing)圈(quan)(quan)、V形(xing)(xing)(xing)(xing)圈(quan)(quan)、U形(xing)(xing)(xing)(xing)圈(quan)(quan)唇(chun)形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)。唇(chun)形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)圈(quan)(quan)主(zhu)要(yao)用于往(wang)復動密(mi)封(feng)(feng)，與O形(xing)(xing)(xing)(xing)圈(quan)(quan)等擠壓密(mi)封(feng)(feng)相(xiang)比，往(wang)復動密(mi)封(feng)(feng)使(shi)用唇(chun)形(xing)(xing)(xing)(xing)密(mi)封(feng)(feng)圈(quan)(quan)具有更(geng)好(hao)的(de)綜合(he)性能和(he)更(geng)長的(de)使(shi)用壽命。

　　唇(chun)形密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)(quan)的密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)(ya)緊(jin)力是(shi)隨介(jie)質(zhi)壓(ya)(ya)(ya)力的改變(bian)而變(bian)化(hua)的，工(gong)(gong)作(zuo)中始終應監控(kong)介(jie)質(zhi)壓(ya)(ya)(ya)力的變(bian)化(hua)，即能(neng)保證(zheng)足(zu)夠的密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壓(ya)(ya)(ya)緊(jin)力，又不至于產(chan)生過(guo)大的摩(mo)擦(ca)力，擠壓(ya)(ya)(ya)性密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)主(zhu)要靠預壓(ya)(ya)(ya)緊(jin)力產(chan)生密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)力，密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)(quan)接(jie)觸(chu)壓(ya)(ya)(ya)力預先給定，工(gong)(gong)作(zuo)中不能(neng)根據介(jie)質(zhi)壓(ya)(ya)(ya)力的改變(bian)而變(bian)化(hua)。大的預壓(ya)(ya)(ya)力會使(shi)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)(quan)與密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)面(mian)接(jie)觸(chu)面(mian)積增大，產(chan)生很大的摩(mo)擦(ca)阻力，過(guo)大的摩(mo)擦(ca)力會造成密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)(quan)的破損，在低(di)壓(ya)(ya)(ya)時造成啟動困難，或(huo)產(chan)生爬(pa)行現象，唇(chun)形密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)圈(quan)(quan)可以通過(guo)唇(chun)部撐開，變(bian)形補償(chang)小的磨(mo)損量，保證(zheng)密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)效(xiao)果和密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)壽命;而O形圈(quan)(quan)隨著摩(mo)擦(ca)余量的減少，直接(jie)影響其密(mi)(mi)(mi)(mi)(mi)封(feng)(feng)性。

　　2、液(ye)壓(ya)密封(feng)件之材(cai)料選(xuan)擇

　　密(mi)(mi)(mi)封(feng)件形式和(he)結構現在一般已經定(ding)型(xing)，各密(mi)(mi)(mi)封(feng)件質量區別(bie)主要在于制(zhi)作(zuo)材(cai)(cai)料(liao)上。密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)主要使(shi)(shi)用橡膠和(he)合(he)成樹(shu)脂。由于各種材(cai)(cai)料(liao)性能(neng)特(te)點不同(tong)，性能(neng)特(te)點不同(tong)，用途也(ye)就(jiu)有(you)(you)(you)所不同(tong)。選用時(shi)需(xu)根據不同(tong)的(de)使(shi)(shi)用條(tiao)件和(he)不同(tong)的(de)使(shi)(shi)用條(tiao)件作(zuo)出合(he)適的(de)選擇。另外，某(mou)一材(cai)(cai)質的(de)密(mi)(mi)(mi)封(feng)對(dui)(dui)(dui)被密(mi)(mi)(mi)封(feng)的(de)某(mou)一工(gong)作(zuo)介(jie)(jie)質(如礦物油等)表(biao)現較好的(de)密(mi)(mi)(mi)封(feng)性能(neng)，而對(dui)(dui)(dui)另一介(jie)(jie)質表(biao)現極(ji)差，這就(jiu)是密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)與液(ye)壓油的(de)相容性。還有(you)(you)(you)，各種不同(tong)的(de)密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)對(dui)(dui)(dui)你不同(tong)的(de)工(gong)作(zuo)條(tiao)件表(biao)現出不同(tong)的(de)性能(neng)。有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)熱(re)，有(you)(you)(you)些(xie)(xie)(xie)不耐(nai)(nai)(nai)熱(re);有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)酸，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)堿，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)水，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)油;有(you)(you)(you)些(xie)(xie)(xie)抗熱(re)，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)低溫，有(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)(nai)高溫，等等。這些(xie)(xie)(xie)因素在考慮密(mi)(mi)(mi)封(feng)件材(cai)(cai)料(liao)的(de)時(shi)候需(xu)注(zhu)意。