1、液壓(ya)密封件之形式選擇

　　在液壓系統(tong)中(zhong)，常見的(de)(de)密(mi)(mi)封(feng)形(xing)(xing)式有擠(ji)壓型(xing)O形(xing)(xing)密(mi)(mi)封(feng)圈(quan)、Y形(xing)(xing)圈(quan)、V形(xing)(xing)圈(quan)、U形(xing)(xing)圈(quan)唇(chun)(chun)形(xing)(xing)密(mi)(mi)封(feng)。唇(chun)(chun)形(xing)(xing)密(mi)(mi)封(feng)圈(quan)主要用于(yu)往復動密(mi)(mi)封(feng)，與O形(xing)(xing)圈(quan)等擠(ji)壓密(mi)(mi)封(feng)相(xiang)比，往復動密(mi)(mi)封(feng)使用唇(chun)(chun)形(xing)(xing)密(mi)(mi)封(feng)圈(quan)具(ju)有更好的(de)(de)綜(zong)合(he)性(xing)能和更長的(de)(de)使用壽(shou)命。

　　唇形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊力(li)(li)(li)(li)是隨介質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)(li)(li)的(de)改變(bian)(bian)(bian)而變(bian)(bian)(bian)化的(de)，工作中始終應監控(kong)介質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)(li)(li)的(de)變(bian)(bian)(bian)化，即能保證足夠的(de)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)緊力(li)(li)(li)(li)，又不(bu)至于(yu)產生過(guo)(guo)大(da)的(de)摩(mo)(mo)(mo)擦(ca)力(li)(li)(li)(li)，擠壓(ya)(ya)(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)主要(yao)靠預(yu)壓(ya)(ya)(ya)(ya)緊力(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)(ya)(ya)(ya)力(li)(li)(li)(li)預(yu)先給定，工作中不(bu)能根(gen)據介質(zhi)壓(ya)(ya)(ya)(ya)力(li)(li)(li)(li)的(de)改變(bian)(bian)(bian)而變(bian)(bian)(bian)化。大(da)的(de)預(yu)壓(ya)(ya)(ya)(ya)力(li)(li)(li)(li)會使密(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)面接(jie)觸面積(ji)增大(da)，產生很大(da)的(de)摩(mo)(mo)(mo)擦(ca)阻力(li)(li)(li)(li)，過(guo)(guo)大(da)的(de)摩(mo)(mo)(mo)擦(ca)力(li)(li)(li)(li)會造成(cheng)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)的(de)破損，在低壓(ya)(ya)(ya)(ya)時造成(cheng)啟動困難，或(huo)產生爬行現象，唇形密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)圈(quan)可以通過(guo)(guo)唇部(bu)撐開，變(bian)(bian)(bian)形補償小的(de)磨(mo)損量(liang)，保證密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)效(xiao)果(guo)和(he)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)壽命;而O形圈(quan)隨著摩(mo)(mo)(mo)擦(ca)余量(liang)的(de)減少，直接(jie)影響其(qi)密(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)性。

　　2、液(ye)壓密封(feng)件(jian)之材料(liao)選擇(ze)

　　密(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)形式和結構現(xian)在(zai)一(yi)(yi)般已經定型，各密(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)質(zhi)(zhi)(zhi)量區別(bie)主要在(zai)于(yu)制作(zuo)(zuo)材料(liao)(liao)上。密(mi)(mi)封(feng)(feng)(feng)(feng)材料(liao)(liao)主要使用(yong)(yong)橡膠(jiao)和合成(cheng)樹脂。由于(yu)各種材料(liao)(liao)性(xing)(xing)(xing)能(neng)特點不(bu)同，性(xing)(xing)(xing)能(neng)特點不(bu)同，用(yong)(yong)途也就有(you)所(suo)不(bu)同。選用(yong)(yong)時需根據不(bu)同的(de)(de)使用(yong)(yong)條(tiao)件(jian)(jian)和不(bu)同的(de)(de)使用(yong)(yong)條(tiao)件(jian)(jian)作(zuo)(zuo)出合適的(de)(de)選擇。另(ling)外，某一(yi)(yi)材質(zhi)(zhi)(zhi)的(de)(de)密(mi)(mi)封(feng)(feng)(feng)(feng)對被(bei)密(mi)(mi)封(feng)(feng)(feng)(feng)的(de)(de)某一(yi)(yi)工作(zuo)(zuo)介(jie)質(zhi)(zhi)(zhi)(如礦物油等)表現(xian)較好的(de)(de)密(mi)(mi)封(feng)(feng)(feng)(feng)性(xing)(xing)(xing)能(neng)，而對另(ling)一(yi)(yi)介(jie)質(zhi)(zhi)(zhi)表現(xian)極差，這(zhe)就是密(mi)(mi)封(feng)(feng)(feng)(feng)材料(liao)(liao)與液壓(ya)油的(de)(de)相容性(xing)(xing)(xing)。還有(you)，各種不(bu)同的(de)(de)密(mi)(mi)封(feng)(feng)(feng)(feng)材料(liao)(liao)對你不(bu)同的(de)(de)工作(zuo)(zuo)條(tiao)件(jian)(jian)表現(xian)出不(bu)同的(de)(de)性(xing)(xing)(xing)能(neng)。有(you)些(xie)(xie)耐(nai)熱(re)(re)，有(you)些(xie)(xie)不(bu)耐(nai)熱(re)(re);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(re)(re)，有(you)些(xie)(xie)耐(nai)低溫(wen)，有(you)些(xie)(xie)耐(nai)高溫(wen)，等等。這(zhe)些(xie)(xie)因素在(zai)考(kao)慮密(mi)(mi)封(feng)(feng)(feng)(feng)件(jian)(jian)材料(liao)(liao)的(de)(de)時候(hou)需注意。