填(tian)(tian)(tian)(tian)(tian)料改集式密(mi)(mi)封(feng)(feng)是指通過預(yu)緊或介質(zhi)壓(ya)力的自緊作(zuo)用(yong)使填(tian)(tian)(tian)(tian)(tian)料與轉(zhuan)動(dong)件及固定(ding)件之(zhi)間產生(sheng)壓(ya)緊力的動(dong)密(mi)(mi)封(feng)(feng)裝置(zhi)。又(you)稱“填(tian)(tian)(tian)(tian)(tian)料函密(mi)(mi)封(feng)(feng)”。結(jie)構(gou)形(xing)式較多，主要由(you)填(tian)(tian)(tian)(tian)(tian)料、填(tian)(tian)(tian)(tian)(tian)料箱和填(tian)(tian)(tian)(tian)(tian)料固定(ding)件組成。常用(yong)的填(tian)(tian)(tian)(tian)(tian)料材(cai)料有(you)石(shi)棉(mian)織物、碳纖維(wei)、橡膠、柔(rou)性(xing)石(shi)墨和工程塑(su)料等，預(yu)制成環狀或條狀（有(you)的需預(yu)先浸漬潤(run)滑(hua)性(xing)好的填(tian)(tian)(tian)(tian)(tian)充物），并(bing)采用(yong)多環或螺旋狀多層結(jie)構(gou)。填(tian)(tian)(tian)(tian)(tian)料箱用(yong)以(yi)安置(zhi)填(tian)(tian)(tian)(tian)(tian)料。填(tian)(tian)(tian)(tian)(tian)料固定(ding)件包括壓(ya)蓋、螺栓(shuan)和彈(dan)(dan)簧(huang)等，用(yong)以(yi)使填(tian)(tian)(tian)(tian)(tian)料預(yu)緊，工作(zuo)時阻止(zhi)介質(zhi)外漏，彈(dan)(dan)簧(huang)可起補償作(zuo)用(yong)。

　　填(tian)(tian)(tian)(tian)料(liao)裝入填(tian)(tian)(tian)(tian)料(liao)腔以后(hou)，經壓蓋螺絲對它(ta)作(zuo)軸(zhou)(zhou)(zhou)向壓縮，當(dang)軸(zhou)(zhou)(zhou)與(yu)(yu)(yu)填(tian)(tian)(tian)(tian)料(liao)有相(xiang)對運動時(shi)，由于(yu)填(tian)(tian)(tian)(tian)料(liao)的(de)塑性(xing)，使它(ta)產生徑向力，并與(yu)(yu)(yu)軸(zhou)(zhou)(zhou)緊(jin)密接(jie)觸(chu)。與(yu)(yu)(yu)此同時(shi)，填(tian)(tian)(tian)(tian)料(liao)中浸漬(zi)的(de)潤(run)滑(hua)劑被擠出(chu)，在接(jie)觸(chu)面之間形成(cheng)油膜(mo)。由于(yu)接(jie)觸(chu)狀(zhuang)態并不(bu)是特(te)別均勻的(de)，接(jie)觸(chu)部(bu)位便出(chu)現“邊(bian)界(jie)潤(run)滑(hua)”狀(zhuang)態，稱為“軸(zhou)(zhou)(zhou)承(cheng)效(xiao)應”；而未(wei)接(jie)觸(chu)的(de)凹(ao)部(bu)形成(cheng)小油槽(cao)，有較厚(hou)的(de)油膜(mo)，接(jie)觸(chu)部(bu)位與(yu)(yu)(yu)非(fei)接(jie)觸(chu)部(bu)位組成(cheng)一(yi)道不(bu)規則(ze)的(de)迷(mi)(mi)宮(gong)，起阻(zu)止液流泄漏的(de)作(zuo)用，此稱“迷(mi)(mi)宮(gong)效(xiao)應”。這(zhe)就是填(tian)(tian)(tian)(tian)料(liao)密封的(de)機理。顯然，良好的(de)密封在于(yu)維持“軸(zhou)(zhou)(zhou)承(cheng)效(xiao)應”和(he)(he)“迷(mi)(mi)宮(gong)效(xiao)應”。也(ye)就是說，要保持良好的(de)潤(run)滑(hua)和(he)(he)適當(dang)的(de)壓緊(jin)。若潤(run)滑(hua)不(bu)良，或壓得過緊(jin)都會使油膜(mo)中斷，造(zao)成(cheng)填(tian)(tian)(tian)(tian)料(liao)與(yu)(yu)(yu)軸(zhou)(zhou)(zhou)之間出(chu)現干摩擦，最后(hou)導致燒軸(zhou)(zhou)(zhou)和(he)(he)出(chu)現嚴重磨損。

　　為此，需要經常對填料的壓(ya)緊程度進行(xing)調整，以便填料中(zhong)的潤滑劑(ji)在運行(xing)一段時(shi)間流失之后，再擠出一些潤滑劑(ji)，同時(shi)補償填料因體積變化(hua)所造成的壓(ya)緊力松弛。顯然，這樣經常擠壓(ya)填料，最(zui)終將(jiang)使浸漬(zi)劑(ji)枯(ku)竭，所以定(ding)期(qi)更(geng)換(huan)填料是必(bi)要的。此外，為了維持液膜(mo)和(he)帶走(zou)摩擦熱，有(you)意讓填料處(chu)有(you)少量泄漏也是必(bi)要的。