填(tian)(tian)(tian)料(liao)(liao)(liao)改(gai)集(ji)式密(mi)封是指通過預(yu)緊(jin)或介質(zhi)壓(ya)力的自緊(jin)作用(yong)(yong)(yong)使填(tian)(tian)(tian)料(liao)(liao)(liao)與轉動(dong)件(jian)(jian)及固(gu)定件(jian)(jian)之(zhi)間產(chan)生壓(ya)緊(jin)力的動(dong)密(mi)封裝置(zhi)。又稱(cheng)“填(tian)(tian)(tian)料(liao)(liao)(liao)函密(mi)封”。結構形(xing)式較多(duo)(duo)，主(zhu)要由填(tian)(tian)(tian)料(liao)(liao)(liao)、填(tian)(tian)(tian)料(liao)(liao)(liao)箱(xiang)和(he)填(tian)(tian)(tian)料(liao)(liao)(liao)固(gu)定件(jian)(jian)組成。常用(yong)(yong)(yong)的填(tian)(tian)(tian)料(liao)(liao)(liao)材料(liao)(liao)(liao)有石(shi)棉織物(wu)、碳纖(xian)維、橡膠(jiao)、柔性石(shi)墨和(he)工程塑料(liao)(liao)(liao)等(deng)，預(yu)制(zhi)成環(huan)(huan)狀(zhuang)或條狀(zhuang)（有的需預(yu)先浸(jin)漬潤滑性好的填(tian)(tian)(tian)充(chong)物(wu)），并(bing)采(cai)用(yong)(yong)(yong)多(duo)(duo)環(huan)(huan)或螺旋(xuan)狀(zhuang)多(duo)(duo)層(ceng)結構。填(tian)(tian)(tian)料(liao)(liao)(liao)箱(xiang)用(yong)(yong)(yong)以(yi)安(an)置(zhi)填(tian)(tian)(tian)料(liao)(liao)(liao)。填(tian)(tian)(tian)料(liao)(liao)(liao)固(gu)定件(jian)(jian)包括(kuo)壓(ya)蓋、螺栓(shuan)和(he)彈簧等(deng)，用(yong)(yong)(yong)以(yi)使填(tian)(tian)(tian)料(liao)(liao)(liao)預(yu)緊(jin)，工作時阻止介質(zhi)外(wai)漏，彈簧可起(qi)補償作用(yong)(yong)(yong)。

　　填(tian)(tian)料(liao)裝入填(tian)(tian)料(liao)腔以后(hou)，經壓(ya)蓋(gai)螺絲對它作軸(zhou)向壓(ya)縮，當軸(zhou)與填(tian)(tian)料(liao)有相(xiang)對運動(dong)時(shi)，由(you)于(yu)填(tian)(tian)料(liao)的(de)(de)塑性，使它產生徑向力，并與軸(zhou)緊密(mi)接(jie)(jie)觸(chu)(chu)(chu)。與此同時(shi)，填(tian)(tian)料(liao)中浸漬的(de)(de)潤(run)滑劑被擠(ji)出(chu)，在(zai)接(jie)(jie)觸(chu)(chu)(chu)面(mian)之(zhi)(zhi)間形成(cheng)油(you)膜(mo)。由(you)于(yu)接(jie)(jie)觸(chu)(chu)(chu)狀(zhuang)態并不(bu)是(shi)特別均勻(yun)的(de)(de)，接(jie)(jie)觸(chu)(chu)(chu)部(bu)位便出(chu)現“邊界潤(run)滑”狀(zhuang)態，稱為“軸(zhou)承(cheng)效應”；而未(wei)接(jie)(jie)觸(chu)(chu)(chu)的(de)(de)凹部(bu)形成(cheng)小油(you)槽，有較厚的(de)(de)油(you)膜(mo)，接(jie)(jie)觸(chu)(chu)(chu)部(bu)位與非接(jie)(jie)觸(chu)(chu)(chu)部(bu)位組成(cheng)一道不(bu)規(gui)則的(de)(de)迷宮，起阻止液流泄漏的(de)(de)作用(yong)，此稱“迷宮效應”。這就是(shi)填(tian)(tian)料(liao)密(mi)封的(de)(de)機理。顯然(ran)，良好的(de)(de)密(mi)封在(zai)于(yu)維(wei)持“軸(zhou)承(cheng)效應”和(he)“迷宮效應”。也就是(shi)說，要保持良好的(de)(de)潤(run)滑和(he)適當的(de)(de)壓(ya)緊。若(ruo)潤(run)滑不(bu)良，或壓(ya)得過(guo)緊都會使油(you)膜(mo)中斷，造成(cheng)填(tian)(tian)料(liao)與軸(zhou)之(zhi)(zhi)間出(chu)現干摩擦，最后(hou)導致(zhi)燒(shao)軸(zhou)和(he)出(chu)現嚴(yan)重(zhong)磨損(sun)。

　　為(wei)此，需要經常(chang)對填(tian)(tian)料(liao)(liao)(liao)(liao)的壓(ya)(ya)緊(jin)程度進行調(diao)整，以便填(tian)(tian)料(liao)(liao)(liao)(liao)中(zhong)的潤滑(hua)劑(ji)(ji)在運行一(yi)(yi)段時間流失之(zhi)后，再擠出一(yi)(yi)些潤滑(hua)劑(ji)(ji)，同時補償填(tian)(tian)料(liao)(liao)(liao)(liao)因體(ti)積(ji)變化(hua)所造(zao)成(cheng)的壓(ya)(ya)緊(jin)力松(song)弛。顯然，這樣經常(chang)擠壓(ya)(ya)填(tian)(tian)料(liao)(liao)(liao)(liao)，最終將(jiang)使浸漬劑(ji)(ji)枯竭，所以定期更(geng)換填(tian)(tian)料(liao)(liao)(liao)(liao)是必要的。此外，為(wei)了維持液膜和(he)帶(dai)走摩(mo)擦熱，有意(yi)讓填(tian)(tian)料(liao)(liao)(liao)(liao)處有少量(liang)泄漏也(ye)是必要的。