在使用過程中，大多數阜南機械密封都屬于接觸式密封，其機理是靠動密封環與靜密封環的接觸端面在密封流體壓力和彈性元件壓緊力的作用下緊密貼合，并相對滑動而達到密封。工作時，阜南機械密封端面上同時發生摩擦、滑動與磨損等現象，摩擦是它的基本特征。阜南機械密封端(duan)(duan)面(mian)摩(mo)(mo)擦(ca)(ca)(ca)的(de)工況(kuang)一(yi)般(ban)分為：流(liu)體摩(mo)(mo)擦(ca)(ca)(ca)、混(hun)合摩(mo)(mo)擦(ca)(ca)(ca)和邊界摩(mo)(mo)擦(ca)(ca)(ca)三類，但不能長時(shi)間干摩(mo)(mo)擦(ca)(ca)(ca)。干摩(mo)(mo)擦(ca)(ca)(ca)狀態時(shi)，兩(liang)端(duan)(duan)面(mian)間的(de)固體表(biao)面(mian)微凸體將直接(jie)接(jie)觸而(er)引起(qi)劇烈(lie)的(de)磨損(sun)(sun)。磨損(sun)(sun)時(shi)一(yi)方面(mian)會使摩(mo)(mo)擦(ca)(ca)(ca)表(biao)面(mian)物質喪(sang)失或遷移，導致表(biao)面(mian)損(sun)(sun)壞；另一(yi)方面(mian)會產生大量的(de)摩(mo)(mo)擦(ca)(ca)(ca)熱(re)直至燒毀密封(feng)。在(zai)無流(liu)體介(jie)質的(de)工況(kuang)下，如(ru)何減少磨損(sun)(sun)降低摩(mo)(mo)擦(ca)(ca)(ca)熱(re)，那就要依(yi)靠干磨密封(feng)了。

　　干(gan)磨(mo)(mo)(mo)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)屬于(yu)(yu)浮動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)的(de)一(yi)種，常(chang)用(yong)(yong)材(cai)質(zhi)為(wei)耐磨(mo)(mo)(mo)碳(tan)精，結構(gou)包括環(huan)(huan)(huan)(huan)(huan)(huan)行密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)腔(qiang)體和環(huan)(huan)(huan)(huan)(huan)(huan)行軸(zhou)套，密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)腔(qiang)體內(nei)有(you)環(huan)(huan)(huan)(huan)(huan)(huan)行槽，槽內(nei)至少裝(zhuang)有(you)二個截面(mian)為(wei)矩形的(de)環(huan)(huan)(huan)(huan)(huan)(huan)行石墨(mo)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)，石墨(mo)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)的(de)內(nei)徑與(yu)(yu)(yu)環(huan)(huan)(huan)(huan)(huan)(huan)行軸(zhou)套之間(jian)有(you)0.01-0.04的(de)間(jian)隙，軸(zhou)套外(wai)(wai)表面(mian)涂有(you)耐磨(mo)(mo)(mo)涂層，涂層材(cai)料一(yi)般為(wei)三氧化二鋁或(huo)三氧化二鉻。干(gan)磨(mo)(mo)(mo)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)有(you)時需要增(zeng)加隔(ge)離氣，通常(chang)使(shi)用(yong)(yong)氮(dan)氣，氮(dan)氣耗量能控制在25-40。主要應用(yong)(yong)于(yu)(yu)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)易燃有(you)毒介質(zhi)，由于(yu)(yu)操(cao)作維修簡(jian)單(dan)，密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)性好，不需要復雜的(de)潤滑冷(leng)卻系(xi)統(tong)，可以干(gan)運行，得到廣泛的(de)應用(yong)(yong)。干(gan)磨(mo)(mo)(mo)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)包括有(you)外(wai)(wai)罩(zhao)及(ji)架設于(yu)(yu)外(wai)(wai)罩(zhao)上(shang)且(qie)可呈相(xiang)對旋轉及(ji)貼合(he)的(de)動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)及(ji)靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)，靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)外(wai)(wai)罩(zhao)固定(ding)連接，靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)及(ji)動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)上(shang)分(fen)開設有(you)供旋轉軸(zhou)安裝(zhuang)的(de)通孔(kong)，且(qie)動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)貼合(he)的(de)端面(mian)分(fen)別為(wei)動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)面(mian)及(ji)靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)面(mian)，外(wai)(wai)罩(zhao)上(shang)設有(you)促使(shi)動(dong)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)與(yu)(yu)(yu)靜(jing)密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)環(huan)(huan)(huan)(huan)(huan)(huan)緊密(mi)(mi)(mi)(mi)(mi)(mi)貼合(he)的(de)彈性抵壓件。除了(le)要保(bao)持密(mi)(mi)(mi)(mi)(mi)(mi)封(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)(feng)面(mian)平行之外(wai)(wai)，主要是(shi)摩擦副的(de)材(cai)料問(wen)題。

　　摩擦(ca)材料應具備(bei)下(xia)列條件：

　　(1)機械強(qiang)度(du)高(gao)，能耐壓和耐壓力(li)變形；

　　(2)具有耐干磨性(xing)，耐高載荷性(xing)，自潤(run)滑性(xing)好(hao)；

　　(3)配對(dui)材料(liao)的磨合性(xing)好，無(wu)過大(da)的磨損(sun)和對(dui)偶腐(fu)蝕；

　　(4)耐(nai)磨性好，摩擦(ca)材料雖(sui)然(ran)是易損(sun)件(jian)，起(qi)到保護制(zhi)動或(huo)傳(chuan)動裝(zhuang)置的(de)作用(yong)，但要求具有(you)一定的(de)耐(nai)磨性，使用(yong)壽命(ming)盡量要長，刮(gua)傷、腐(fu)蝕(shi)和粘附對偶，都會(hui)造成制(zhi)動或(huo)傳(chuan)動的(de)震動和不穩定；

　　(5)導熱性(xing)(xing)和散熱性(xing)(xing)好(hao)(hao)，導熱性(xing)(xing)是(shi)傳導熱量的能力大小，即包(bao)括(kuo)吸熱，也(ye)包(bao)括(kuo)散熱，所以，導熱性(xing)(xing)好(hao)(hao)的必然散熱性(xing)(xing)也(ye)好(hao)(hao)；

　　(6)抗熱裂(lie)性好，根本解決抗熱裂(lie)性問(wen)題可能(neng)需要改(gai)變封孔方(fang)法；

　　(7)耐腐蝕(shi)性強，一些有色金(jin)屬(shu)合(he)金(jin)能將良(liang)好的摩擦(ca)學特性與有些流(liu)體的耐腐蝕(shi)性結(jie)合(he)；

　　(8)線(xian)膨(peng)脹(zhang)系數小，熱膨(peng)脹(zhang)會造成摩擦材料與摩擦對(dui)偶之間(jian)的(de)間(jian)隙過小，發生(sheng)拖摩，損毀制動(dong)、傳動(dong)裝置。