1、液壓密封(feng)件之形(xing)式選擇

　　在液壓系統中(zhong)，常見的密(mi)(mi)封(feng)(feng)形(xing)(xing)(xing)(xing)式有擠壓型O形(xing)(xing)(xing)(xing)密(mi)(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)唇形(xing)(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)。唇形(xing)(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)圈(quan)(quan)主要用于往(wang)復(fu)動密(mi)(mi)封(feng)(feng)，與(yu)O形(xing)(xing)(xing)(xing)圈(quan)(quan)等擠壓密(mi)(mi)封(feng)(feng)相比，往(wang)復(fu)動密(mi)(mi)封(feng)(feng)使(shi)用唇形(xing)(xing)(xing)(xing)密(mi)(mi)封(feng)(feng)圈(quan)(quan)具有更(geng)好的綜(zong)合性(xing)能和(he)更(geng)長的使(shi)用壽命。

　　唇(chun)形(xing)密(mi)(mi)(mi)(mi)封圈的(de)(de)(de)(de)密(mi)(mi)(mi)(mi)封壓(ya)(ya)緊力是隨介質(zhi)(zhi)壓(ya)(ya)力的(de)(de)(de)(de)改變(bian)(bian)(bian)(bian)而變(bian)(bian)(bian)(bian)化(hua)的(de)(de)(de)(de)，工(gong)作(zuo)中(zhong)始終(zhong)應監控介質(zhi)(zhi)壓(ya)(ya)力的(de)(de)(de)(de)變(bian)(bian)(bian)(bian)化(hua)，即(ji)能保證(zheng)足夠(gou)的(de)(de)(de)(de)密(mi)(mi)(mi)(mi)封壓(ya)(ya)緊力，又不至于(yu)產生(sheng)(sheng)(sheng)過(guo)大的(de)(de)(de)(de)摩擦(ca)力，擠壓(ya)(ya)性(xing)密(mi)(mi)(mi)(mi)封主要靠預(yu)壓(ya)(ya)緊力產生(sheng)(sheng)(sheng)密(mi)(mi)(mi)(mi)封力，密(mi)(mi)(mi)(mi)封圈接觸壓(ya)(ya)力預(yu)先(xian)給定，工(gong)作(zuo)中(zhong)不能根據介質(zhi)(zhi)壓(ya)(ya)力的(de)(de)(de)(de)改變(bian)(bian)(bian)(bian)而變(bian)(bian)(bian)(bian)化(hua)。大的(de)(de)(de)(de)預(yu)壓(ya)(ya)力會使密(mi)(mi)(mi)(mi)封圈與密(mi)(mi)(mi)(mi)封面接觸面積增大，產生(sheng)(sheng)(sheng)很大的(de)(de)(de)(de)摩擦(ca)阻力，過(guo)大的(de)(de)(de)(de)摩擦(ca)力會造成密(mi)(mi)(mi)(mi)封圈的(de)(de)(de)(de)破損，在低壓(ya)(ya)時造成啟動困難，或產生(sheng)(sheng)(sheng)爬(pa)行現象，唇(chun)形(xing)密(mi)(mi)(mi)(mi)封圈可(ke)以通過(guo)唇(chun)部撐開，變(bian)(bian)(bian)(bian)形(xing)補償(chang)小(xiao)的(de)(de)(de)(de)磨(mo)損量，保證(zheng)密(mi)(mi)(mi)(mi)封效(xiao)果(guo)和密(mi)(mi)(mi)(mi)封壽命;而O形(xing)圈隨著(zhu)摩擦(ca)余量的(de)(de)(de)(de)減(jian)少，直接影響(xiang)其密(mi)(mi)(mi)(mi)封性(xing)。

　　2、液(ye)壓密封件之材料(liao)選擇

　　密(mi)封(feng)(feng)(feng)件(jian)(jian)(jian)形式(shi)和(he)結(jie)構現在一(yi)般已(yi)經定(ding)型，各密(mi)封(feng)(feng)(feng)件(jian)(jian)(jian)質(zhi)量(liang)區別主(zhu)要在于(yu)制作(zuo)(zuo)材料上。密(mi)封(feng)(feng)(feng)材料主(zhu)要使用(yong)(yong)橡(xiang)膠(jiao)和(he)合(he)成樹脂。由于(yu)各種材料性(xing)能(neng)特(te)點(dian)不同(tong)(tong)，性(xing)能(neng)特(te)點(dian)不同(tong)(tong)，用(yong)(yong)途也(ye)就有(you)所不同(tong)(tong)。選用(yong)(yong)時(shi)(shi)需(xu)根據(ju)不同(tong)(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)(jian)和(he)不同(tong)(tong)的(de)(de)(de)使用(yong)(yong)條件(jian)(jian)(jian)作(zuo)(zuo)出(chu)合(he)適的(de)(de)(de)選擇(ze)。另(ling)外，某一(yi)材質(zhi)的(de)(de)(de)密(mi)封(feng)(feng)(feng)對(dui)被密(mi)封(feng)(feng)(feng)的(de)(de)(de)某一(yi)工(gong)作(zuo)(zuo)介質(zhi)(如礦物油等)表(biao)現較好的(de)(de)(de)密(mi)封(feng)(feng)(feng)性(xing)能(neng)，而對(dui)另(ling)一(yi)介質(zhi)表(biao)現極差，這就是密(mi)封(feng)(feng)(feng)材料與液壓油的(de)(de)(de)相容性(xing)。還(huan)有(you)，各種不同(tong)(tong)的(de)(de)(de)密(mi)封(feng)(feng)(feng)材料對(dui)你(ni)不同(tong)(tong)的(de)(de)(de)工(gong)作(zuo)(zuo)條件(jian)(jian)(jian)表(biao)現出(chu)不同(tong)(tong)的(de)(de)(de)性(xing)能(neng)。有(you)些(xie)(xie)耐(nai)熱，有(you)些(xie)(xie)不耐(nai)熱;有(you)些(xie)(xie)耐(nai)酸，有(you)些(xie)(xie)耐(nai)堿，有(you)些(xie)(xie)耐(nai)水(shui)，有(you)些(xie)(xie)耐(nai)油;有(you)些(xie)(xie)抗熱，有(you)些(xie)(xie)耐(nai)低溫，有(you)些(xie)(xie)耐(nai)高溫，等等。這些(xie)(xie)因(yin)素在考慮密(mi)封(feng)(feng)(feng)件(jian)(jian)(jian)材料的(de)(de)(de)時(shi)(shi)候需(xu)注意。