填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)改集式密封是(shi)指(zhi)通過預(yu)(yu)緊(jin)(jin)(jin)(jin)或(huo)介(jie)質壓(ya)力(li)的(de)自緊(jin)(jin)(jin)(jin)作用(yong)使(shi)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)與轉動(dong)件(jian)(jian)及固(gu)定(ding)(ding)件(jian)(jian)之間產(chan)生壓(ya)緊(jin)(jin)(jin)(jin)力(li)的(de)動(dong)密封裝置(zhi)。又稱“填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)函密封”。結(jie)構(gou)(gou)形(xing)式較多，主(zhu)要由(you)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱和(he)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)固(gu)定(ding)(ding)件(jian)(jian)組成。常用(yong)的(de)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)材料(liao)(liao)(liao)(liao)有石棉織(zhi)物、碳纖維、橡膠、柔(rou)性石墨和(he)工程塑料(liao)(liao)(liao)(liao)等(deng)，預(yu)(yu)制成環狀(zhuang)或(huo)條狀(zhuang)（有的(de)需(xu)預(yu)(yu)先浸漬潤(run)滑性好的(de)填(tian)(tian)(tian)(tian)(tian)充物），并采用(yong)多環或(huo)螺旋狀(zhuang)多層(ceng)結(jie)構(gou)(gou)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)箱用(yong)以安置(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(ding)(ding)件(jian)(jian)包括壓(ya)蓋、螺栓和(he)彈簧等(deng)，用(yong)以使(shi)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)預(yu)(yu)緊(jin)(jin)(jin)(jin)，工作時阻止介(jie)質外漏(lou)，彈簧可起補償作用(yong)。

　　填料(liao)(liao)裝入(ru)填料(liao)(liao)腔以后，經壓(ya)(ya)蓋螺絲對它作(zuo)軸(zhou)向(xiang)(xiang)壓(ya)(ya)縮(suo)，當(dang)軸(zhou)與填料(liao)(liao)有(you)相對運動(dong)時(shi)，由于(yu)填料(liao)(liao)的(de)(de)塑性(xing)，使它產生徑向(xiang)(xiang)力，并與軸(zhou)緊密(mi)接(jie)(jie)(jie)觸。與此(ci)同時(shi)，填料(liao)(liao)中(zhong)浸漬的(de)(de)潤(run)滑劑被擠出(chu)，在接(jie)(jie)(jie)觸面之間(jian)形成(cheng)油(you)膜(mo)(mo)。由于(yu)接(jie)(jie)(jie)觸狀(zhuang)態(tai)(tai)并不是(shi)特別均勻的(de)(de)，接(jie)(jie)(jie)觸部位(wei)便出(chu)現“邊界(jie)潤(run)滑”狀(zhuang)態(tai)(tai)，稱(cheng)為“軸(zhou)承(cheng)效(xiao)應(ying)”；而(er)未接(jie)(jie)(jie)觸的(de)(de)凹部形成(cheng)小油(you)槽，有(you)較厚的(de)(de)油(you)膜(mo)(mo)，接(jie)(jie)(jie)觸部位(wei)與非接(jie)(jie)(jie)觸部位(wei)組成(cheng)一道不規則的(de)(de)迷(mi)宮，起阻止液流(liu)泄漏(lou)的(de)(de)作(zuo)用，此(ci)稱(cheng)“迷(mi)宮效(xiao)應(ying)”。這就是(shi)填料(liao)(liao)密(mi)封的(de)(de)機理。顯然，良好(hao)的(de)(de)密(mi)封在于(yu)維(wei)持“軸(zhou)承(cheng)效(xiao)應(ying)”和(he)“迷(mi)宮效(xiao)應(ying)”。也(ye)就是(shi)說，要保持良好(hao)的(de)(de)潤(run)滑和(he)適當(dang)的(de)(de)壓(ya)(ya)緊。若潤(run)滑不良，或壓(ya)(ya)得過緊都會使油(you)膜(mo)(mo)中(zhong)斷，造(zao)成(cheng)填料(liao)(liao)與軸(zhou)之間(jian)出(chu)現干摩擦，最后導致燒軸(zhou)和(he)出(chu)現嚴重磨損。

　　為此(ci)，需(xu)要(yao)經(jing)(jing)常對填(tian)料(liao)的壓(ya)緊(jin)(jin)程度進行(xing)調整，以便(bian)填(tian)料(liao)中的潤滑劑在運行(xing)一段時間流失之后，再擠出一些潤滑劑，同時補償填(tian)料(liao)因體積變(bian)化所造成的壓(ya)緊(jin)(jin)力松弛。顯然(ran)，這(zhe)樣經(jing)(jing)常擠壓(ya)填(tian)料(liao)，最(zui)終將使浸漬(zi)劑枯竭，所以定期更換填(tian)料(liao)是(shi)必(bi)要(yao)的。此(ci)外(wai)，為了(le)維(wei)持液膜和(he)帶走(zou)摩(mo)擦(ca)熱，有(you)意讓填(tian)料(liao)處有(you)少(shao)量泄(xie)漏也是(shi)必(bi)要(yao)的。