填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)改(gai)集式(shi)密(mi)封(feng)是指通過(guo)預(yu)緊(jin)(jin)或(huo)(huo)介(jie)質壓力的自緊(jin)(jin)作(zuo)用(yong)使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)與轉動(dong)件(jian)及固(gu)定件(jian)之間(jian)產(chan)生壓緊(jin)(jin)力的動(dong)密(mi)封(feng)裝(zhuang)置。又(you)稱(cheng)“填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)函密(mi)封(feng)”。結(jie)構(gou)形式(shi)較多，主(zhu)要由填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)、填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)箱和(he)填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)固(gu)定件(jian)組成(cheng)(cheng)。常用(yong)的填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)材料(liao)(liao)(liao)(liao)(liao)有(you)石棉織(zhi)物、碳纖維、橡(xiang)膠、柔性(xing)石墨和(he)工程(cheng)塑(su)料(liao)(liao)(liao)(liao)(liao)等，預(yu)制成(cheng)(cheng)環(huan)狀(zhuang)或(huo)(huo)條狀(zhuang)（有(you)的需預(yu)先(xian)浸漬潤滑性(xing)好的填(tian)(tian)(tian)(tian)(tian)充(chong)物），并(bing)采(cai)用(yong)多環(huan)或(huo)(huo)螺(luo)旋狀(zhuang)多層結(jie)構(gou)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)箱用(yong)以安置填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)。填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)固(gu)定件(jian)包括壓蓋(gai)、螺(luo)栓和(he)彈(dan)簧等，用(yong)以使填(tian)(tian)(tian)(tian)(tian)料(liao)(liao)(liao)(liao)(liao)預(yu)緊(jin)(jin)，工作(zuo)時阻止介(jie)質外漏(lou)，彈(dan)簧可起補償作(zuo)用(yong)。

　　填(tian)料(liao)裝入填(tian)料(liao)腔以(yi)后(hou)，經壓(ya)蓋(gai)螺絲對(dui)它作軸(zhou)向(xiang)壓(ya)縮，當軸(zhou)與(yu)填(tian)料(liao)有(you)相對(dui)運動(dong)時，由于填(tian)料(liao)的塑性，使它產生(sheng)徑向(xiang)力(li)，并與(yu)軸(zhou)緊(jin)(jin)密接(jie)(jie)(jie)觸(chu)(chu)。與(yu)此同時，填(tian)料(liao)中浸漬(zi)的潤(run)(run)滑(hua)劑被擠(ji)出(chu)(chu)，在(zai)接(jie)(jie)(jie)觸(chu)(chu)面(mian)之(zhi)間(jian)形成(cheng)油(you)膜。由于接(jie)(jie)(jie)觸(chu)(chu)狀態(tai)并不是特別均勻(yun)的，接(jie)(jie)(jie)觸(chu)(chu)部位(wei)便出(chu)(chu)現(xian)“邊界(jie)潤(run)(run)滑(hua)”狀態(tai)，稱為“軸(zhou)承效(xiao)應(ying)”；而(er)未接(jie)(jie)(jie)觸(chu)(chu)的凹部形成(cheng)小油(you)槽，有(you)較厚的油(you)膜，接(jie)(jie)(jie)觸(chu)(chu)部位(wei)與(yu)非接(jie)(jie)(jie)觸(chu)(chu)部位(wei)組(zu)成(cheng)一道不規則(ze)的迷宮(gong)，起阻止液流泄(xie)漏的作用，此稱“迷宮(gong)效(xiao)應(ying)”。這就(jiu)是填(tian)料(liao)密封的機(ji)理。顯然，良好(hao)的密封在(zai)于維持“軸(zhou)承效(xiao)應(ying)”和(he)“迷宮(gong)效(xiao)應(ying)”。也就(jiu)是說(shuo)，要保持良好(hao)的潤(run)(run)滑(hua)和(he)適當的壓(ya)緊(jin)(jin)。若(ruo)潤(run)(run)滑(hua)不良，或壓(ya)得過緊(jin)(jin)都會使油(you)膜中斷，造成(cheng)填(tian)料(liao)與(yu)軸(zhou)之(zhi)間(jian)出(chu)(chu)現(xian)干摩擦，最后(hou)導致燒軸(zhou)和(he)出(chu)(chu)現(xian)嚴重磨(mo)損。

　　為(wei)此，需(xu)要(yao)經常(chang)對(dui)填(tian)(tian)料(liao)的壓(ya)緊程度進行(xing)調整(zheng)，以便填(tian)(tian)料(liao)中的潤(run)滑劑在(zai)運行(xing)一(yi)段時間流失(shi)之后，再擠出一(yi)些潤(run)滑劑，同時補償(chang)填(tian)(tian)料(liao)因體積變(bian)化所造成的壓(ya)緊力松弛。顯然，這樣經常(chang)擠壓(ya)填(tian)(tian)料(liao)，最終將使(shi)浸漬(zi)劑枯(ku)竭，所以定期更換填(tian)(tian)料(liao)是(shi)(shi)必要(yao)的。此外，為(wei)了維持液膜和帶走摩擦熱，有意讓填(tian)(tian)料(liao)處有少量泄漏(lou)也(ye)是(shi)(shi)必要(yao)的。