1、液壓密(mi)封件之形式選(xuan)擇

　　在液壓(ya)系統(tong)中(zhong)，常見(jian)的(de)(de)密(mi)封形(xing)式(shi)有擠壓(ya)型O形(xing)密(mi)封圈、Y形(xing)圈、V形(xing)圈、U形(xing)圈唇形(xing)密(mi)封。唇形(xing)密(mi)封圈主要用(yong)于(yu)往復(fu)(fu)動密(mi)封，與O形(xing)圈等擠壓(ya)密(mi)封相比，往復(fu)(fu)動密(mi)封使(shi)用(yong)唇形(xing)密(mi)封圈具有更好的(de)(de)綜合性(xing)能和(he)更長的(de)(de)使(shi)用(yong)壽命(ming)。

　　唇形(xing)密(mi)(mi)(mi)(mi)封(feng)圈(quan)的(de)(de)密(mi)(mi)(mi)(mi)封(feng)壓(ya)(ya)(ya)(ya)(ya)緊力(li)是隨介質壓(ya)(ya)(ya)(ya)(ya)力(li)的(de)(de)改變(bian)而(er)變(bian)化(hua)的(de)(de)，工作中始終應監控介質壓(ya)(ya)(ya)(ya)(ya)力(li)的(de)(de)變(bian)化(hua)，即(ji)能保(bao)證足夠的(de)(de)密(mi)(mi)(mi)(mi)封(feng)壓(ya)(ya)(ya)(ya)(ya)緊力(li)，又不至于產生(sheng)過大(da)的(de)(de)摩擦(ca)力(li)，擠壓(ya)(ya)(ya)(ya)(ya)性密(mi)(mi)(mi)(mi)封(feng)主要靠預壓(ya)(ya)(ya)(ya)(ya)緊力(li)產生(sheng)密(mi)(mi)(mi)(mi)封(feng)力(li)，密(mi)(mi)(mi)(mi)封(feng)圈(quan)接(jie)觸(chu)壓(ya)(ya)(ya)(ya)(ya)力(li)預先給(gei)定(ding)，工作中不能根據介質壓(ya)(ya)(ya)(ya)(ya)力(li)的(de)(de)改變(bian)而(er)變(bian)化(hua)。大(da)的(de)(de)預壓(ya)(ya)(ya)(ya)(ya)力(li)會使密(mi)(mi)(mi)(mi)封(feng)圈(quan)與密(mi)(mi)(mi)(mi)封(feng)面接(jie)觸(chu)面積增大(da)，產生(sheng)很大(da)的(de)(de)摩擦(ca)阻(zu)力(li)，過大(da)的(de)(de)摩擦(ca)力(li)會造(zao)成密(mi)(mi)(mi)(mi)封(feng)圈(quan)的(de)(de)破(po)損，在低(di)壓(ya)(ya)(ya)(ya)(ya)時造(zao)成啟動困難，或產生(sheng)爬行(xing)現象，唇形(xing)密(mi)(mi)(mi)(mi)封(feng)圈(quan)可(ke)以通過唇部撐開，變(bian)形(xing)補償(chang)小的(de)(de)磨損量，保(bao)證密(mi)(mi)(mi)(mi)封(feng)效果和密(mi)(mi)(mi)(mi)封(feng)壽命(ming);而(er)O形(xing)圈(quan)隨著摩擦(ca)余量的(de)(de)減(jian)少，直接(jie)影響其密(mi)(mi)(mi)(mi)封(feng)性。

　　2、液壓密封件之材(cai)料選擇

　　密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)形式和結構現(xian)(xian)在一(yi)(yi)般已(yi)經定型，各密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)質量區別(bie)主要在于制作(zuo)材(cai)(cai)(cai)料(liao)(liao)上(shang)。密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料(liao)(liao)主要使(shi)用(yong)(yong)橡膠和合成樹(shu)脂(zhi)。由于各種(zhong)材(cai)(cai)(cai)料(liao)(liao)性(xing)(xing)能特點不(bu)同(tong)(tong)，性(xing)(xing)能特點不(bu)同(tong)(tong)，用(yong)(yong)途也就(jiu)有(you)(you)所不(bu)同(tong)(tong)。選(xuan)用(yong)(yong)時需根據不(bu)同(tong)(tong)的(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)和不(bu)同(tong)(tong)的(de)(de)使(shi)用(yong)(yong)條(tiao)件(jian)作(zuo)出合適(shi)的(de)(de)選(xuan)擇。另外，某一(yi)(yi)材(cai)(cai)(cai)質的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)對(dui)被密(mi)(mi)(mi)(mi)封(feng)(feng)的(de)(de)某一(yi)(yi)工(gong)作(zuo)介(jie)質(如礦物油等)表現(xian)(xian)較好的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)性(xing)(xing)能，而對(dui)另一(yi)(yi)介(jie)質表現(xian)(xian)極差，這(zhe)就(jiu)是(shi)密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料(liao)(liao)與液壓油的(de)(de)相容性(xing)(xing)。還有(you)(you)，各種(zhong)不(bu)同(tong)(tong)的(de)(de)密(mi)(mi)(mi)(mi)封(feng)(feng)材(cai)(cai)(cai)料(liao)(liao)對(dui)你(ni)不(bu)同(tong)(tong)的(de)(de)工(gong)作(zuo)條(tiao)件(jian)表現(xian)(xian)出不(bu)同(tong)(tong)的(de)(de)性(xing)(xing)能。有(you)(you)些(xie)耐(nai)熱，有(you)(you)些(xie)不(bu)耐(nai)熱;有(you)(you)些(xie)耐(nai)酸(suan)，有(you)(you)些(xie)耐(nai)堿，有(you)(you)些(xie)耐(nai)水，有(you)(you)些(xie)耐(nai)油;有(you)(you)些(xie)抗熱，有(you)(you)些(xie)耐(nai)低(di)溫，有(you)(you)些(xie)耐(nai)高溫，等等。這(zhe)些(xie)因(yin)素(su)在考慮(lv)密(mi)(mi)(mi)(mi)封(feng)(feng)件(jian)材(cai)(cai)(cai)料(liao)(liao)的(de)(de)時候需注意。