填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)改集(ji)式密(mi)封(feng)是指通過預(yu)緊(jin)或介質(zhi)壓力(li)的自(zi)緊(jin)作用(yong)(yong)使填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)與(yu)轉(zhuan)動件(jian)及固(gu)(gu)定件(jian)之間產生壓緊(jin)力(li)的動密(mi)封(feng)裝置(zhi)。又稱(cheng)“填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)函密(mi)封(feng)”。結構(gou)形式較多，主要由填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)箱和(he)填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)固(gu)(gu)定件(jian)組成。常用(yong)(yong)的填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)材料(liao)(liao)有石棉織物、碳(tan)纖維、橡膠、柔性石墨(mo)和(he)工(gong)(gong)程塑料(liao)(liao)等，預(yu)制成環狀或條狀（有的需預(yu)先浸漬潤滑性好的填(tian)(tian)(tian)(tian)(tian)(tian)(tian)充物），并采用(yong)(yong)多環或螺(luo)旋狀多層結構(gou)。填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)箱用(yong)(yong)以(yi)安置(zhi)填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)。填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)固(gu)(gu)定件(jian)包括(kuo)壓蓋、螺(luo)栓和(he)彈(dan)簧等，用(yong)(yong)以(yi)使填(tian)(tian)(tian)(tian)(tian)(tian)(tian)料(liao)(liao)預(yu)緊(jin)，工(gong)(gong)作時阻止介質(zhi)外漏，彈(dan)簧可起補償作用(yong)(yong)。

　　填(tian)料(liao)裝入(ru)填(tian)料(liao)腔以后(hou)，經(jing)壓(ya)蓋螺絲對(dui)它作(zuo)軸向(xiang)(xiang)壓(ya)縮，當軸與填(tian)料(liao)有相對(dui)運(yun)動時，由(you)于(yu)填(tian)料(liao)的(de)(de)(de)塑性，使(shi)它產生徑向(xiang)(xiang)力，并與軸緊(jin)密接(jie)(jie)(jie)觸(chu)(chu)(chu)。與此(ci)同時，填(tian)料(liao)中(zhong)浸漬的(de)(de)(de)潤(run)滑(hua)(hua)劑被擠出(chu)(chu)，在接(jie)(jie)(jie)觸(chu)(chu)(chu)面之(zhi)間形成(cheng)油(you)(you)膜。由(you)于(yu)接(jie)(jie)(jie)觸(chu)(chu)(chu)狀態(tai)并不(bu)是特(te)別均勻的(de)(de)(de)，接(jie)(jie)(jie)觸(chu)(chu)(chu)部(bu)位(wei)便出(chu)(chu)現“邊界(jie)潤(run)滑(hua)(hua)”狀態(tai)，稱為“軸承效應”；而未接(jie)(jie)(jie)觸(chu)(chu)(chu)的(de)(de)(de)凹部(bu)形成(cheng)小油(you)(you)槽，有較厚的(de)(de)(de)油(you)(you)膜，接(jie)(jie)(jie)觸(chu)(chu)(chu)部(bu)位(wei)與非接(jie)(jie)(jie)觸(chu)(chu)(chu)部(bu)位(wei)組(zu)成(cheng)一道不(bu)規則(ze)的(de)(de)(de)迷宮，起阻止(zhi)液流泄漏(lou)的(de)(de)(de)作(zuo)用，此(ci)稱“迷宮效應”。這就是填(tian)料(liao)密封(feng)的(de)(de)(de)機理。顯(xian)然(ran)，良(liang)好的(de)(de)(de)密封(feng)在于(yu)維持(chi)“軸承效應”和(he)“迷宮效應”。也就是說(shuo)，要保持(chi)良(liang)好的(de)(de)(de)潤(run)滑(hua)(hua)和(he)適當的(de)(de)(de)壓(ya)緊(jin)。若潤(run)滑(hua)(hua)不(bu)良(liang)，或(huo)壓(ya)得過緊(jin)都會使(shi)油(you)(you)膜中(zhong)斷，造成(cheng)填(tian)料(liao)與軸之(zhi)間出(chu)(chu)現干摩擦(ca)，最后(hou)導致(zhi)燒軸和(he)出(chu)(chu)現嚴(yan)重磨損。

　　為此，需要(yao)(yao)經(jing)常對填(tian)(tian)(tian)料(liao)的壓緊(jin)程度(du)進行調(diao)整，以便填(tian)(tian)(tian)料(liao)中的潤(run)滑劑在(zai)運行一段時間(jian)流失之(zhi)后，再擠出一些潤(run)滑劑，同(tong)時補償填(tian)(tian)(tian)料(liao)因(yin)體(ti)積變化(hua)所造成的壓緊(jin)力(li)松弛。顯(xian)然，這(zhe)樣經(jing)常擠壓填(tian)(tian)(tian)料(liao)，最終將(jiang)使(shi)浸漬劑枯竭，所以定(ding)期更換填(tian)(tian)(tian)料(liao)是(shi)必(bi)要(yao)(yao)的。此外(wai)，為了維持液膜和帶走摩擦熱，有(you)意讓填(tian)(tian)(tian)料(liao)處(chu)有(you)少量泄漏(lou)也是(shi)必(bi)要(yao)(yao)的。