1、液壓密封件之形式選擇(ze)

　　在(zai)液壓(ya)系統中，常見的(de)密(mi)(mi)(mi)(mi)封(feng)形(xing)(xing)式有(you)擠壓(ya)型O形(xing)(xing)密(mi)(mi)(mi)(mi)封(feng)圈(quan)、Y形(xing)(xing)圈(quan)、V形(xing)(xing)圈(quan)、U形(xing)(xing)圈(quan)唇形(xing)(xing)密(mi)(mi)(mi)(mi)封(feng)。唇形(xing)(xing)密(mi)(mi)(mi)(mi)封(feng)圈(quan)主要用于往(wang)復動密(mi)(mi)(mi)(mi)封(feng)，與O形(xing)(xing)圈(quan)等擠壓(ya)密(mi)(mi)(mi)(mi)封(feng)相(xiang)比，往(wang)復動密(mi)(mi)(mi)(mi)封(feng)使用唇形(xing)(xing)密(mi)(mi)(mi)(mi)封(feng)圈(quan)具有(you)更(geng)好的(de)綜合性能和更(geng)長的(de)使用壽(shou)命。

　　唇形(xing)密(mi)封(feng)(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)密(mi)封(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)緊力(li)(li)(li)(li)是隨介(jie)質壓(ya)(ya)力(li)(li)(li)(li)的(de)(de)(de)(de)改變(bian)而變(bian)化(hua)的(de)(de)(de)(de)，工作(zuo)中始(shi)終應監控(kong)介(jie)質壓(ya)(ya)力(li)(li)(li)(li)的(de)(de)(de)(de)變(bian)化(hua)，即能(neng)保證(zheng)足夠的(de)(de)(de)(de)密(mi)封(feng)(feng)(feng)(feng)(feng)壓(ya)(ya)緊力(li)(li)(li)(li)，又不至于產生(sheng)過大的(de)(de)(de)(de)摩擦力(li)(li)(li)(li)，擠(ji)壓(ya)(ya)性密(mi)封(feng)(feng)(feng)(feng)(feng)主要靠(kao)預壓(ya)(ya)緊力(li)(li)(li)(li)產生(sheng)密(mi)封(feng)(feng)(feng)(feng)(feng)力(li)(li)(li)(li)，密(mi)封(feng)(feng)(feng)(feng)(feng)圈接觸壓(ya)(ya)力(li)(li)(li)(li)預先(xian)給定，工作(zuo)中不能(neng)根據(ju)介(jie)質壓(ya)(ya)力(li)(li)(li)(li)的(de)(de)(de)(de)改變(bian)而變(bian)化(hua)。大的(de)(de)(de)(de)預壓(ya)(ya)力(li)(li)(li)(li)會(hui)(hui)使密(mi)封(feng)(feng)(feng)(feng)(feng)圈與密(mi)封(feng)(feng)(feng)(feng)(feng)面接觸面積增大，產生(sheng)很大的(de)(de)(de)(de)摩擦阻力(li)(li)(li)(li)，過大的(de)(de)(de)(de)摩擦力(li)(li)(li)(li)會(hui)(hui)造(zao)成密(mi)封(feng)(feng)(feng)(feng)(feng)圈的(de)(de)(de)(de)破損(sun)，在(zai)低(di)壓(ya)(ya)時(shi)造(zao)成啟動(dong)困難，或(huo)產生(sheng)爬行(xing)現象，唇形(xing)密(mi)封(feng)(feng)(feng)(feng)(feng)圈可以通過唇部撐(cheng)開，變(bian)形(xing)補償小(xiao)的(de)(de)(de)(de)磨損(sun)量，保證(zheng)密(mi)封(feng)(feng)(feng)(feng)(feng)效果和(he)密(mi)封(feng)(feng)(feng)(feng)(feng)壽命;而O形(xing)圈隨著(zhu)摩擦余量的(de)(de)(de)(de)減少，直接影響(xiang)其密(mi)封(feng)(feng)(feng)(feng)(feng)性。

　　2、液壓密封(feng)件之材料選(xuan)擇

　　密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)形式和(he)結構現在(zai)(zai)一般已經定(ding)型(xing)，各密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)質(zhi)(zhi)(zhi)量區(qu)別主(zhu)要(yao)在(zai)(zai)于制作(zuo)材(cai)(cai)(cai)(cai)料(liao)上。密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)(cai)(cai)(cai)料(liao)主(zhu)要(yao)使用(yong)(yong)橡膠和(he)合成樹脂。由(you)于各種(zhong)材(cai)(cai)(cai)(cai)料(liao)性(xing)能(neng)特點不(bu)(bu)(bu)同(tong)，性(xing)能(neng)特點不(bu)(bu)(bu)同(tong)，用(yong)(yong)途(tu)也就有(you)(you)所(suo)不(bu)(bu)(bu)同(tong)。選(xuan)用(yong)(yong)時需(xu)根(gen)據不(bu)(bu)(bu)同(tong)的(de)使用(yong)(yong)條件(jian)和(he)不(bu)(bu)(bu)同(tong)的(de)使用(yong)(yong)條件(jian)作(zuo)出(chu)合適的(de)選(xuan)擇。另(ling)(ling)外，某(mou)一材(cai)(cai)(cai)(cai)質(zhi)(zhi)(zhi)的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)對被密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)的(de)某(mou)一工作(zuo)介(jie)質(zhi)(zhi)(zhi)(如礦物油等)表現較好的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)性(xing)能(neng)，而對另(ling)(ling)一介(jie)質(zhi)(zhi)(zhi)表現極差，這就是密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)(cai)(cai)(cai)料(liao)與(yu)液壓(ya)油的(de)相容(rong)性(xing)。還有(you)(you)，各種(zhong)不(bu)(bu)(bu)同(tong)的(de)密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)材(cai)(cai)(cai)(cai)料(liao)對你不(bu)(bu)(bu)同(tong)的(de)工作(zuo)條件(jian)表現出(chu)不(bu)(bu)(bu)同(tong)的(de)性(xing)能(neng)。有(you)(you)些耐(nai)(nai)熱(re)，有(you)(you)些不(bu)(bu)(bu)耐(nai)(nai)熱(re);有(you)(you)些耐(nai)(nai)酸，有(you)(you)些耐(nai)(nai)堿，有(you)(you)些耐(nai)(nai)水，有(you)(you)些耐(nai)(nai)油;有(you)(you)些抗熱(re)，有(you)(you)些耐(nai)(nai)低(di)溫(wen)，有(you)(you)些耐(nai)(nai)高溫(wen)，等等。這些因素在(zai)(zai)考慮密(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)件(jian)材(cai)(cai)(cai)(cai)料(liao)的(de)時候需(xu)注(zhu)意。