1、液壓密封件(jian)之形式選擇

　　在液壓系統中，常見的密封形(xing)式有(you)擠(ji)(ji)壓型O形(xing)密封圈(quan)(quan)、Y形(xing)圈(quan)(quan)、V形(xing)圈(quan)(quan)、U形(xing)圈(quan)(quan)唇(chun)形(xing)密封。唇(chun)形(xing)密封圈(quan)(quan)主要用于往復動密封，與(yu)O形(xing)圈(quan)(quan)等擠(ji)(ji)壓密封相(xiang)比(bi)，往復動密封使用唇(chun)形(xing)密封圈(quan)(quan)具有(you)更(geng)好的綜合性能(neng)和更(geng)長(chang)的使用壽命。

　　唇形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)的密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)壓緊力(li)是(shi)隨介(jie)質(zhi)壓力(li)的改變(bian)而(er)變(bian)化(hua)(hua)的，工作中始終(zhong)應監控介(jie)質(zhi)壓力(li)的變(bian)化(hua)(hua)，即(ji)能保(bao)證足(zu)夠的密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)壓緊力(li)，又不(bu)至于產(chan)生過大(da)的摩(mo)擦(ca)力(li)，擠(ji)壓性(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)主要靠預(yu)壓緊力(li)產(chan)生密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)力(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)接(jie)觸(chu)壓力(li)預(yu)先給定，工作中不(bu)能根據介(jie)質(zhi)壓力(li)的改變(bian)而(er)變(bian)化(hua)(hua)。大(da)的預(yu)壓力(li)會(hui)使密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)與密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)面接(jie)觸(chu)面積增大(da)，產(chan)生很(hen)大(da)的摩(mo)擦(ca)阻力(li)，過大(da)的摩(mo)擦(ca)力(li)會(hui)造(zao)成密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)的破(po)損，在(zai)低壓時造(zao)成啟動困難，或產(chan)生爬行現(xian)象(xiang)，唇形(xing)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)圈(quan)(quan)(quan)可以通過唇部撐開，變(bian)形(xing)補償小的磨損量，保(bao)證密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)效果和(he)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)壽(shou)命;而(er)O形(xing)圈(quan)(quan)(quan)隨著(zhu)摩(mo)擦(ca)余量的減(jian)少，直接(jie)影響其密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)性(xing)。

　　2、液(ye)壓(ya)密封(feng)件之材料選擇

　　密(mi)(mi)封(feng)(feng)(feng)件(jian)形式和(he)(he)結構現(xian)(xian)在(zai)一(yi)般已經定型，各(ge)(ge)密(mi)(mi)封(feng)(feng)(feng)件(jian)質量區別主要在(zai)于(yu)制作材料上。密(mi)(mi)封(feng)(feng)(feng)材料主要使用(yong)橡膠(jiao)和(he)(he)合(he)成樹脂(zhi)。由于(yu)各(ge)(ge)種材料性能(neng)特點不(bu)同(tong)(tong)(tong)，性能(neng)特點不(bu)同(tong)(tong)(tong)，用(yong)途(tu)也就有(you)(you)所(suo)不(bu)同(tong)(tong)(tong)。選用(yong)時需根(gen)據(ju)不(bu)同(tong)(tong)(tong)的(de)(de)(de)使用(yong)條(tiao)件(jian)和(he)(he)不(bu)同(tong)(tong)(tong)的(de)(de)(de)使用(yong)條(tiao)件(jian)作出合(he)適的(de)(de)(de)選擇。另外，某(mou)一(yi)材質的(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(如礦物(wu)油(you)等)表(biao)現(xian)(xian)較好的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)性能(neng)，而對另一(yi)介質表(biao)現(xian)(xian)極差，這就是密(mi)(mi)封(feng)(feng)(feng)材料與(yu)液壓油(you)的(de)(de)(de)相(xiang)容性。還有(you)(you)，各(ge)(ge)種不(bu)同(tong)(tong)(tong)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)材料對你不(bu)同(tong)(tong)(tong)的(de)(de)(de)工作條(tiao)件(jian)表(biao)現(xian)(xian)出不(bu)同(tong)(tong)(tong)的(de)(de)(de)性能(neng)。有(you)(you)些(xie)(xie)耐(nai)熱(re)，有(you)(you)些(xie)(xie)不(bu)耐(nai)熱(re);有(you)(you)些(xie)(xie)耐(nai)酸，有(you)(you)些(xie)(xie)耐(nai)堿(jian)，有(you)(you)些(xie)(xie)耐(nai)水，有(you)(you)些(xie)(xie)耐(nai)油(you);有(you)(you)些(xie)(xie)抗熱(re)，有(you)(you)些(xie)(xie)耐(nai)低溫，有(you)(you)些(xie)(xie)耐(nai)高溫，等等。這些(xie)(xie)因(yin)素(su)在(zai)考慮密(mi)(mi)封(feng)(feng)(feng)件(jian)材料的(de)(de)(de)時候需注意。