1、液壓密封(feng)件之形式選(xuan)擇

　　在液壓(ya)(ya)(ya)系統中，常見的(de)密(mi)封(feng)形式(shi)有擠壓(ya)(ya)(ya)型(xing)O形密(mi)封(feng)圈(quan)(quan)、Y形圈(quan)(quan)、V形圈(quan)(quan)、U形圈(quan)(quan)唇(chun)形密(mi)封(feng)。唇(chun)形密(mi)封(feng)圈(quan)(quan)主要用(yong)于往復動密(mi)封(feng)，與(yu)O形圈(quan)(quan)等擠壓(ya)(ya)(ya)密(mi)封(feng)相比，往復動密(mi)封(feng)使(shi)用(yong)唇(chun)形密(mi)封(feng)圈(quan)(quan)具有更(geng)好(hao)的(de)綜(zong)合性能和更(geng)長的(de)使(shi)用(yong)壽命。

　　唇形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)緊(jin)力(li)(li)(li)(li)是隨介(jie)質(zhi)壓(ya)力(li)(li)(li)(li)的改(gai)變(bian)而變(bian)化的，工作中始終應監(jian)控介(jie)質(zhi)壓(ya)力(li)(li)(li)(li)的變(bian)化，即能保證足夠的密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)緊(jin)力(li)(li)(li)(li)，又不至于(yu)產生過大(da)的摩(mo)擦力(li)(li)(li)(li)，擠(ji)壓(ya)性(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)主(zhu)要靠預壓(ya)緊(jin)力(li)(li)(li)(li)產生密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)力(li)(li)(li)(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)接(jie)觸壓(ya)力(li)(li)(li)(li)預先給定，工作中不能根據介(jie)質(zhi)壓(ya)力(li)(li)(li)(li)的改(gai)變(bian)而變(bian)化。大(da)的預壓(ya)力(li)(li)(li)(li)會(hui)使密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)與密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)面(mian)接(jie)觸面(mian)積增大(da)，產生很大(da)的摩(mo)擦阻力(li)(li)(li)(li)，過大(da)的摩(mo)擦力(li)(li)(li)(li)會(hui)造(zao)(zao)成密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的破(po)損(sun)，在低壓(ya)時造(zao)(zao)成啟動困難，或產生爬行(xing)現象，唇形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)可(ke)以通過唇部(bu)撐開，變(bian)形(xing)補(bu)償小的磨損(sun)量(liang)(liang)，保證密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)效果和密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壽(shou)命;而O形(xing)圈(quan)隨著摩(mo)擦余量(liang)(liang)的減少，直接(jie)影響其(qi)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)性(xing)。

　　2、液壓密(mi)封件之(zhi)材(cai)料(liao)選擇

　　密(mi)(mi)(mi)封(feng)件(jian)(jian)形(xing)式和(he)結構現在一(yi)(yi)般已經定型，各密(mi)(mi)(mi)封(feng)件(jian)(jian)質(zhi)(zhi)量區(qu)別(bie)主要在于制作材(cai)(cai)料(liao)(liao)上。密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)(liao)主要使(shi)用(yong)(yong)(yong)橡膠和(he)合成樹(shu)脂。由(you)于各種材(cai)(cai)料(liao)(liao)性能(neng)特(te)點不(bu)同(tong)(tong)，性能(neng)特(te)點不(bu)同(tong)(tong)，用(yong)(yong)(yong)途(tu)也就有(you)(you)所不(bu)同(tong)(tong)。選用(yong)(yong)(yong)時(shi)需根(gen)據不(bu)同(tong)(tong)的(de)(de)使(shi)用(yong)(yong)(yong)條件(jian)(jian)和(he)不(bu)同(tong)(tong)的(de)(de)使(shi)用(yong)(yong)(yong)條件(jian)(jian)作出合適的(de)(de)選擇(ze)。另(ling)外，某(mou)一(yi)(yi)材(cai)(cai)質(zhi)(zhi)的(de)(de)密(mi)(mi)(mi)封(feng)對(dui)被密(mi)(mi)(mi)封(feng)的(de)(de)某(mou)一(yi)(yi)工作介質(zhi)(zhi)(如礦物油等)表(biao)現較好的(de)(de)密(mi)(mi)(mi)封(feng)性能(neng)，而(er)對(dui)另(ling)一(yi)(yi)介質(zhi)(zhi)表(biao)現極差，這就是密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)(liao)與液壓(ya)油的(de)(de)相容性。還(huan)有(you)(you)，各種不(bu)同(tong)(tong)的(de)(de)密(mi)(mi)(mi)封(feng)材(cai)(cai)料(liao)(liao)對(dui)你(ni)不(bu)同(tong)(tong)的(de)(de)工作條件(jian)(jian)表(biao)現出不(bu)同(tong)(tong)的(de)(de)性能(neng)。有(you)(you)些(xie)耐(nai)(nai)(nai)熱，有(you)(you)些(xie)不(bu)耐(nai)(nai)(nai)熱;有(you)(you)些(xie)耐(nai)(nai)(nai)酸，有(you)(you)些(xie)耐(nai)(nai)(nai)堿，有(you)(you)些(xie)耐(nai)(nai)(nai)水(shui)，有(you)(you)些(xie)耐(nai)(nai)(nai)油;有(you)(you)些(xie)抗熱，有(you)(you)些(xie)耐(nai)(nai)(nai)低(di)溫，有(you)(you)些(xie)耐(nai)(nai)(nai)高溫，等等。這些(xie)因(yin)素在考慮密(mi)(mi)(mi)封(feng)件(jian)(jian)材(cai)(cai)料(liao)(liao)的(de)(de)時(shi)候需注意。