1、液壓密(mi)封件之形(xing)式選擇(ze)

　　在液壓(ya)系統中(zhong)，常見(jian)的密封(feng)(feng)形(xing)(xing)式有擠(ji)壓(ya)型O形(xing)(xing)密封(feng)(feng)圈(quan)、Y形(xing)(xing)圈(quan)、V形(xing)(xing)圈(quan)、U形(xing)(xing)圈(quan)唇形(xing)(xing)密封(feng)(feng)。唇形(xing)(xing)密封(feng)(feng)圈(quan)主要(yao)用于往(wang)復動密封(feng)(feng)，與(yu)O形(xing)(xing)圈(quan)等擠(ji)壓(ya)密封(feng)(feng)相比，往(wang)復動密封(feng)(feng)使(shi)用唇形(xing)(xing)密封(feng)(feng)圈(quan)具有更好(hao)的綜合性能和更長的使(shi)用壽命。

　　唇(chun)形密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)的密(mi)(mi)封(feng)(feng)(feng)壓(ya)緊力(li)是隨介質壓(ya)力(li)的改(gai)變而(er)變化的，工(gong)(gong)作中始終(zhong)應監控介質壓(ya)力(li)的變化，即能保證(zheng)足夠的密(mi)(mi)封(feng)(feng)(feng)壓(ya)緊力(li)，又不至于(yu)產生(sheng)過大(da)(da)的摩擦力(li)，擠壓(ya)性密(mi)(mi)封(feng)(feng)(feng)主(zhu)要靠(kao)預壓(ya)緊力(li)產生(sheng)密(mi)(mi)封(feng)(feng)(feng)力(li)，密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)接(jie)觸壓(ya)力(li)預先給定(ding)，工(gong)(gong)作中不能根(gen)據(ju)介質壓(ya)力(li)的改(gai)變而(er)變化。大(da)(da)的預壓(ya)力(li)會(hui)使密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)與密(mi)(mi)封(feng)(feng)(feng)面接(jie)觸面積增大(da)(da)，產生(sheng)很大(da)(da)的摩擦阻力(li)，過大(da)(da)的摩擦力(li)會(hui)造(zao)成密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)的破損，在低壓(ya)時(shi)造(zao)成啟動(dong)困難，或產生(sheng)爬(pa)行現象，唇(chun)形密(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)可以(yi)通過唇(chun)部撐(cheng)開，變形補(bu)償小(xiao)的磨損量(liang)，保證(zheng)密(mi)(mi)封(feng)(feng)(feng)效果和密(mi)(mi)封(feng)(feng)(feng)壽命;而(er)O形圈(quan)(quan)隨著摩擦余量(liang)的減少，直接(jie)影響其密(mi)(mi)封(feng)(feng)(feng)性。

　　2、液壓密(mi)封件之材(cai)料選擇

　　密(mi)(mi)封(feng)(feng)件(jian)形式(shi)和(he)結(jie)構現(xian)在一(yi)(yi)般(ban)已經定型，各(ge)(ge)密(mi)(mi)封(feng)(feng)件(jian)質(zhi)量(liang)區(qu)別主要在于(yu)制(zhi)作(zuo)材(cai)料(liao)(liao)上。密(mi)(mi)封(feng)(feng)材(cai)料(liao)(liao)主要使用橡膠和(he)合成樹脂。由于(yu)各(ge)(ge)種材(cai)料(liao)(liao)性能(neng)特點不(bu)(bu)(bu)同(tong)(tong)(tong)，性能(neng)特點不(bu)(bu)(bu)同(tong)(tong)(tong)，用途也就(jiu)有(you)(you)(you)(you)(you)所不(bu)(bu)(bu)同(tong)(tong)(tong)。選(xuan)用時需根據不(bu)(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)使用條(tiao)件(jian)和(he)不(bu)(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)使用條(tiao)件(jian)作(zuo)出(chu)(chu)合適的(de)(de)(de)選(xuan)擇。另外(wai)，某一(yi)(yi)材(cai)質(zhi)的(de)(de)(de)密(mi)(mi)封(feng)(feng)對被密(mi)(mi)封(feng)(feng)的(de)(de)(de)某一(yi)(yi)工作(zuo)介質(zhi)(如(ru)礦物油(you)(you)等)表(biao)現(xian)較好的(de)(de)(de)密(mi)(mi)封(feng)(feng)性能(neng)，而對另一(yi)(yi)介質(zhi)表(biao)現(xian)極差，這就(jiu)是密(mi)(mi)封(feng)(feng)材(cai)料(liao)(liao)與液壓油(you)(you)的(de)(de)(de)相(xiang)容性。還(huan)有(you)(you)(you)(you)(you)，各(ge)(ge)種不(bu)(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)密(mi)(mi)封(feng)(feng)材(cai)料(liao)(liao)對你不(bu)(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)工作(zuo)條(tiao)件(jian)表(biao)現(xian)出(chu)(chu)不(bu)(bu)(bu)同(tong)(tong)(tong)的(de)(de)(de)性能(neng)。有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)熱，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)不(bu)(bu)(bu)耐(nai)(nai)熱;有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)酸，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)堿(jian)，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)水，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)油(you)(you);有(you)(you)(you)(you)(you)些(xie)(xie)(xie)抗熱，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)低溫(wen)，有(you)(you)(you)(you)(you)些(xie)(xie)(xie)耐(nai)(nai)高溫(wen)，等等。這些(xie)(xie)(xie)因素在考慮密(mi)(mi)封(feng)(feng)件(jian)材(cai)料(liao)(liao)的(de)(de)(de)時候需注意。