填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)改集式密(mi)(mi)封(feng)是指通(tong)過預(yu)緊(jin)或(huo)介(jie)質(zhi)壓力(li)(li)的(de)自(zi)緊(jin)作用(yong)使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)與(yu)轉動件(jian)(jian)及固(gu)定件(jian)(jian)之間產生壓緊(jin)力(li)(li)的(de)動密(mi)(mi)封(feng)裝置(zhi)。又稱“填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)函(han)密(mi)(mi)封(feng)”。結構(gou)形式較多，主要由填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱(xiang)和填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)固(gu)定件(jian)(jian)組(zu)成。常用(yong)的(de)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)材料(liao)(liao)(liao)(liao)有石棉(mian)織物(wu)、碳纖維、橡膠、柔性石墨和工(gong)程(cheng)塑料(liao)(liao)(liao)(liao)等，預(yu)制成環(huan)狀(zhuang)或(huo)條狀(zhuang)（有的(de)需預(yu)先浸漬潤(run)滑性好的(de)填(tian)(tian)(tian)(tian)(tian)充物(wu)），并采(cai)用(yong)多環(huan)或(huo)螺(luo)旋狀(zhuang)多層結構(gou)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱(xiang)用(yong)以(yi)安置(zhi)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)固(gu)定件(jian)(jian)包括壓蓋、螺(luo)栓和彈(dan)(dan)簧等，用(yong)以(yi)使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)預(yu)緊(jin)，工(gong)作時阻(zu)止介(jie)質(zhi)外漏(lou)，彈(dan)(dan)簧可(ke)起(qi)補償作用(yong)。

　　填(tian)(tian)料(liao)裝入填(tian)(tian)料(liao)腔以(yi)后，經壓(ya)蓋(gai)螺絲對它作軸(zhou)(zhou)向壓(ya)縮，當軸(zhou)(zhou)與填(tian)(tian)料(liao)有(you)相對運(yun)動時(shi)，由于(yu)填(tian)(tian)料(liao)的(de)(de)塑性，使(shi)它產生徑向力(li)，并(bing)(bing)與軸(zhou)(zhou)緊(jin)密(mi)(mi)接(jie)(jie)觸(chu)(chu)。與此同時(shi)，填(tian)(tian)料(liao)中浸漬的(de)(de)潤滑劑(ji)被擠(ji)出，在(zai)接(jie)(jie)觸(chu)(chu)面之間(jian)形成油(you)膜。由于(yu)接(jie)(jie)觸(chu)(chu)狀態并(bing)(bing)不是特別均勻的(de)(de)，接(jie)(jie)觸(chu)(chu)部(bu)位便出現“邊界潤滑”狀態，稱(cheng)為“軸(zhou)(zhou)承(cheng)效應(ying)(ying)”；而未(wei)接(jie)(jie)觸(chu)(chu)的(de)(de)凹部(bu)形成小(xiao)油(you)槽(cao)，有(you)較(jiao)厚的(de)(de)油(you)膜，接(jie)(jie)觸(chu)(chu)部(bu)位與非接(jie)(jie)觸(chu)(chu)部(bu)位組成一道(dao)不規則的(de)(de)迷(mi)宮(gong)(gong)，起阻止液流泄漏的(de)(de)作用，此稱(cheng)“迷(mi)宮(gong)(gong)效應(ying)(ying)”。這就是填(tian)(tian)料(liao)密(mi)(mi)封的(de)(de)機理。顯然(ran)，良(liang)好(hao)的(de)(de)密(mi)(mi)封在(zai)于(yu)維持“軸(zhou)(zhou)承(cheng)效應(ying)(ying)”和“迷(mi)宮(gong)(gong)效應(ying)(ying)”。也就是說，要保(bao)持良(liang)好(hao)的(de)(de)潤滑和適當的(de)(de)壓(ya)緊(jin)。若(ruo)潤滑不良(liang)，或壓(ya)得(de)過(guo)緊(jin)都會使(shi)油(you)膜中斷，造成填(tian)(tian)料(liao)與軸(zhou)(zhou)之間(jian)出現干摩擦(ca)，最(zui)后導致(zhi)燒軸(zhou)(zhou)和出現嚴重磨損(sun)。

　　為(wei)此(ci)，需(xu)要經常(chang)(chang)對填(tian)料(liao)的(de)壓(ya)緊程度進(jin)行(xing)調整，以便填(tian)料(liao)中的(de)潤滑劑(ji)在運行(xing)一段時間流失之后，再(zai)擠出一些(xie)潤滑劑(ji)，同時補償(chang)填(tian)料(liao)因體積(ji)變化(hua)所造成的(de)壓(ya)緊力松弛。顯然，這(zhe)樣經常(chang)(chang)擠壓(ya)填(tian)料(liao)，最(zui)終將使浸漬(zi)劑(ji)枯竭(jie)，所以定(ding)期更(geng)換填(tian)料(liao)是必要的(de)。此(ci)外，為(wei)了維持(chi)液膜和帶走摩擦(ca)熱，有意(yi)讓填(tian)料(liao)處有少量泄漏也是必要的(de)。