1、液壓密封件(jian)之形式選擇

　　在液壓系(xi)統中，常見的密(mi)(mi)封(feng)(feng)(feng)形(xing)式(shi)有(you)擠壓型O形(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)、Y形(xing)圈(quan)、V形(xing)圈(quan)、U形(xing)圈(quan)唇形(xing)密(mi)(mi)封(feng)(feng)(feng)。唇形(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)主要用于往復動密(mi)(mi)封(feng)(feng)(feng)，與O形(xing)圈(quan)等擠壓密(mi)(mi)封(feng)(feng)(feng)相(xiang)比，往復動密(mi)(mi)封(feng)(feng)(feng)使用唇形(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)具有(you)更好(hao)的綜合性能和更長的使用壽命。

　　唇形(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)緊力是(shi)隨(sui)(sui)介質壓(ya)(ya)力的(de)(de)(de)改變(bian)而變(bian)化(hua)的(de)(de)(de)，工(gong)(gong)作(zuo)(zuo)中始終應(ying)監控(kong)介質壓(ya)(ya)力的(de)(de)(de)變(bian)化(hua)，即能保證足夠(gou)的(de)(de)(de)密(mi)(mi)封(feng)(feng)(feng)壓(ya)(ya)緊力，又不至于產生(sheng)過大(da)的(de)(de)(de)摩(mo)擦(ca)(ca)力，擠(ji)壓(ya)(ya)性(xing)密(mi)(mi)封(feng)(feng)(feng)主要(yao)靠預(yu)壓(ya)(ya)緊力產生(sheng)密(mi)(mi)封(feng)(feng)(feng)力，密(mi)(mi)封(feng)(feng)(feng)圈(quan)接觸(chu)壓(ya)(ya)力預(yu)先給定，工(gong)(gong)作(zuo)(zuo)中不能根(gen)據介質壓(ya)(ya)力的(de)(de)(de)改變(bian)而變(bian)化(hua)。大(da)的(de)(de)(de)預(yu)壓(ya)(ya)力會使(shi)密(mi)(mi)封(feng)(feng)(feng)圈(quan)與密(mi)(mi)封(feng)(feng)(feng)面接觸(chu)面積增大(da)，產生(sheng)很大(da)的(de)(de)(de)摩(mo)擦(ca)(ca)阻力，過大(da)的(de)(de)(de)摩(mo)擦(ca)(ca)力會造(zao)成密(mi)(mi)封(feng)(feng)(feng)圈(quan)的(de)(de)(de)破損，在低壓(ya)(ya)時造(zao)成啟(qi)動困難，或產生(sheng)爬行現(xian)象，唇形(xing)密(mi)(mi)封(feng)(feng)(feng)圈(quan)可以通(tong)過唇部撐(cheng)開，變(bian)形(xing)補(bu)償小的(de)(de)(de)磨(mo)損量，保證密(mi)(mi)封(feng)(feng)(feng)效(xiao)果和密(mi)(mi)封(feng)(feng)(feng)壽命;而O形(xing)圈(quan)隨(sui)(sui)著摩(mo)擦(ca)(ca)余量的(de)(de)(de)減少，直接影響其密(mi)(mi)封(feng)(feng)(feng)性(xing)。

　　2、液壓密封件之(zhi)材料選擇

　　密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)形式和(he)(he)結構現(xian)在(zai)一(yi)般已經定型，各(ge)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)質量區別主要在(zai)于(yu)制(zhi)作(zuo)材(cai)(cai)料(liao)(liao)(liao)上。密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)材(cai)(cai)料(liao)(liao)(liao)主要使用(yong)橡膠和(he)(he)合成樹(shu)脂。由于(yu)各(ge)種材(cai)(cai)料(liao)(liao)(liao)性(xing)能(neng)特點(dian)不同(tong)(tong)(tong)，性(xing)能(neng)特點(dian)不同(tong)(tong)(tong)，用(yong)途也就有(you)所不同(tong)(tong)(tong)。選用(yong)時(shi)需(xu)(xu)根據(ju)不同(tong)(tong)(tong)的(de)使用(yong)條(tiao)件(jian)(jian)和(he)(he)不同(tong)(tong)(tong)的(de)使用(yong)條(tiao)件(jian)(jian)作(zuo)出合適的(de)選擇。另外，某(mou)一(yi)材(cai)(cai)質的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)對被密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)的(de)某(mou)一(yi)工作(zuo)介(jie)(jie)質(如(ru)礦物油等)表(biao)現(xian)較好的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)性(xing)能(neng)，而對另一(yi)介(jie)(jie)質表(biao)現(xian)極差，這就是(shi)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)材(cai)(cai)料(liao)(liao)(liao)與液壓油的(de)相容性(xing)。還有(you)，各(ge)種不同(tong)(tong)(tong)的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)材(cai)(cai)料(liao)(liao)(liao)對你(ni)不同(tong)(tong)(tong)的(de)工作(zuo)條(tiao)件(jian)(jian)表(biao)現(xian)出不同(tong)(tong)(tong)的(de)性(xing)能(neng)。有(you)些(xie)耐(nai)(nai)熱(re)，有(you)些(xie)不耐(nai)(nai)熱(re);有(you)些(xie)耐(nai)(nai)酸，有(you)些(xie)耐(nai)(nai)堿，有(you)些(xie)耐(nai)(nai)水(shui)，有(you)些(xie)耐(nai)(nai)油;有(you)些(xie)抗(kang)熱(re)，有(you)些(xie)耐(nai)(nai)低溫，有(you)些(xie)耐(nai)(nai)高溫，等等。這些(xie)因素在(zai)考慮密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)材(cai)(cai)料(liao)(liao)(liao)的(de)時(shi)候需(xu)(xu)注意。