1、液壓密封件之(zhi)形式選擇

　　在液壓系(xi)統中(zhong)，常見的(de)密(mi)(mi)封形(xing)(xing)式有(you)擠(ji)壓型O形(xing)(xing)密(mi)(mi)封圈(quan)、Y形(xing)(xing)圈(quan)、V形(xing)(xing)圈(quan)、U形(xing)(xing)圈(quan)唇形(xing)(xing)密(mi)(mi)封。唇形(xing)(xing)密(mi)(mi)封圈(quan)主要用(yong)(yong)于(yu)往(wang)復動(dong)密(mi)(mi)封，與O形(xing)(xing)圈(quan)等(deng)擠(ji)壓密(mi)(mi)封相比，往(wang)復動(dong)密(mi)(mi)封使用(yong)(yong)唇形(xing)(xing)密(mi)(mi)封圈(quan)具有(you)更(geng)(geng)好的(de)綜(zong)合性(xing)能和更(geng)(geng)長的(de)使用(yong)(yong)壽命。

　　唇形密(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)是隨介質壓(ya)(ya)力(li)的(de)(de)(de)改(gai)變(bian)而(er)變(bian)化的(de)(de)(de)，工(gong)作(zuo)中(zhong)始終應監控(kong)介質壓(ya)(ya)力(li)的(de)(de)(de)變(bian)化，即(ji)能保證足夠的(de)(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壓(ya)(ya)緊力(li)，又不至于產(chan)生過大(da)的(de)(de)(de)摩(mo)擦力(li)，擠壓(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)主要靠預壓(ya)(ya)緊力(li)產(chan)生密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)力(li)，密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)接觸壓(ya)(ya)力(li)預先給定，工(gong)作(zuo)中(zhong)不能根據(ju)介質壓(ya)(ya)力(li)的(de)(de)(de)改(gai)變(bian)而(er)變(bian)化。大(da)的(de)(de)(de)預壓(ya)(ya)力(li)會(hui)使密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)與密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)面接觸面積增大(da)，產(chan)生很(hen)大(da)的(de)(de)(de)摩(mo)擦阻力(li)，過大(da)的(de)(de)(de)摩(mo)擦力(li)會(hui)造(zao)成(cheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)的(de)(de)(de)破損(sun)，在低壓(ya)(ya)時(shi)造(zao)成(cheng)啟(qi)動困(kun)難，或(huo)產(chan)生爬行(xing)現象，唇形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)圈(quan)可以通過唇部撐開，變(bian)形補(bu)償(chang)小的(de)(de)(de)磨損(sun)量，保證密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)效果和密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)壽命(ming);而(er)O形圈(quan)隨著摩(mo)擦余量的(de)(de)(de)減(jian)少(shao)，直接影響其密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)性。

　　2、液壓密封件之材料選擇(ze)

　　密(mi)封(feng)件(jian)(jian)(jian)形式和結構現在一般已(yi)經定型(xing)，各密(mi)封(feng)件(jian)(jian)(jian)質量(liang)區別主(zhu)要(yao)在于(yu)制作材料上(shang)。密(mi)封(feng)材料主(zhu)要(yao)使用(yong)(yong)橡膠(jiao)和合(he)成樹脂。由于(yu)各種材料性(xing)(xing)能(neng)特點不(bu)(bu)(bu)(bu)同(tong)，性(xing)(xing)能(neng)特點不(bu)(bu)(bu)(bu)同(tong)，用(yong)(yong)途也(ye)就有(you)(you)(you)所不(bu)(bu)(bu)(bu)同(tong)。選用(yong)(yong)時需根據不(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)(jian)和不(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)(jian)作出合(he)適的(de)(de)(de)選擇。另外，某一材質的(de)(de)(de)密(mi)封(feng)對(dui)(dui)被密(mi)封(feng)的(de)(de)(de)某一工作介(jie)質(如礦物油(you)等(deng)(deng))表現較好的(de)(de)(de)密(mi)封(feng)性(xing)(xing)能(neng)，而對(dui)(dui)另一介(jie)質表現極差(cha)，這(zhe)就是密(mi)封(feng)材料與液壓油(you)的(de)(de)(de)相容性(xing)(xing)。還(huan)有(you)(you)(you)，各種不(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)密(mi)封(feng)材料對(dui)(dui)你不(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)工作條件(jian)(jian)(jian)表現出不(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)性(xing)(xing)能(neng)。有(you)(you)(you)些(xie)耐(nai)熱，有(you)(you)(you)些(xie)不(bu)(bu)(bu)(bu)耐(nai)熱;有(you)(you)(you)些(xie)耐(nai)酸，有(you)(you)(you)些(xie)耐(nai)堿，有(you)(you)(you)些(xie)耐(nai)水，有(you)(you)(you)些(xie)耐(nai)油(you);有(you)(you)(you)些(xie)抗熱，有(you)(you)(you)些(xie)耐(nai)低(di)溫，有(you)(you)(you)些(xie)耐(nai)高溫，等(deng)(deng)等(deng)(deng)。這(zhe)些(xie)因素在考慮密(mi)封(feng)件(jian)(jian)(jian)材料的(de)(de)(de)時候需注意。