電風扇工(gong)作(zuo)原理(li)及(ji)檢修

風扇的分類：

散熱風扇通常分為以下三類：

軸流式：氣流出口方(fang)向與軸心方(fang)向相同。

離心式(shi)：利用離心力作用將(jiang)氣流沿著葉片向外(wai)甩出。

混流式：擁(yong)有(you)以(yi)上兩(liang)種氣流方式。

電風扇電路圖

該圖片由注冊用戶"力與美"提供，版權聲明反饋

以上是比較常見的(de)(de)家(jia)用電(dian)風(feng)扇的(de)(de)電(dian)路圖(tu)，從中我(wo)們也不難看出它的(de)(de)一些原理，但是現在(zai)電(dian)風(feng)扇產品越來越多，其(qi)電(dian)路圖(tu)也越來越復雜，但是還是萬(wan)變不離其(qi)中。

電風扇工作原理

電風(feng)扇中(zhong)的(de)電流是(shi)交流電，主要(yao)的(de)工作原理就是(shi)通電線圈在磁場中(zhong)受力(li)而轉(zhuan)動。電能轉(zhuan)化為機(ji)械(xie)能，轉(zhuan)動風(feng)葉，同時由于線圈電阻，會產生一些熱能，所以一般(ban)電風(feng)扇使用過(guo)久表面會熱。電風(feng)扇的(de)原理比較簡單，一般(ban)在初中(zhong)的(de)物理課程上都會學到。

電風扇轉不動的原因

首先還是要確定一下是不是一些外部原因。諸如插頭沒有插好，風扇開關沒有全部開啟，一般的風扇還應該注意是否定時的關掉了，如果這些都沒有問題的話，就可能是電風扇扇本身的原因。

電(dian)(dian)風(feng)(feng)扇(shan)本身的(de)原(yuan)因可(ke)能包括了(le)風(feng)(feng)葉可(ke)能太久(jiu)了(le)，電(dian)(dian)機的(de)內阻(zu)變大(da)，導(dao)致(zhi)風(feng)(feng)葉無法正常轉(zhuan)動(dong)；風(feng)(feng)扇(shan)過熱引起了(le)電(dian)(dian)機帶負載能力變差，導(dao)致(zhi)無法轉(zhuan)動(dong)；電(dian)(dian)機內部(bu)的(de)保(bao)護(hu)裝置過熱短路；電(dian)(dian)風(feng)(feng)扇(shan)的(de)啟(qi)動(dong)電(dian)(dian)容容量變小；電(dian)(dian)風(feng)(feng)扇(shan)轉(zhuan)軸軸向間隙過大(da)也會引發電(dian)(dian)風(feng)(feng)扇(shan)問題。

電風扇轉不動的修理方法

先檢查一(yi)(yi)下電(dian)風扇以外的(de)問題是(shi)不(bu)是(shi)全部都弄妥當了(le)(le)；然后如果(guo)是(shi)風葉(xie)不(bu)轉(zhuan)的(de)話就關閉(bi)電(dian)源，在風葉(xie)轉(zhuan)動的(de)軸上面加一(yi)(yi)些潤滑油；其他的(de)問題可能(neng)就會涉(she)及到更(geng)換(huan)(huan)軸套、拆換(huan)(huan)電(dian)容、調整墊片、電(dian)線(xian)損壞更(geng)換(huan)(huan)電(dian)線(xian)等問題，一(yi)(yi)般不(bu)是(shi)專業的(de)人員就要請(qing)維修師傅(fu)來(lai)看一(yi)(yi)下了(le)(le)，不(bu)過一(yi)(yi)般也(ye)不(bu)是(shi)好大的(de)問題，也(ye)花不(bu)了(le)(le)多少錢(qian)。

散熱風扇的原理及性能

原理：風扇(shan)的(de)工作原(yuan)理(li)是按能(neng)(neng)量轉化來(lai)實現的(de)，即(ji)：電能(neng)(neng)→電磁能(neng)(neng)→機械能(neng)(neng)→動能(neng)(neng)。其電路(lu)原(yuan)理(li)一(yi)般分(fen)為多(duo)種形式，采(cai)用的(de)電路(lu)不同，風扇(shan)的(de)性(xing)能(neng)(neng)就會有差異。

轉 速：轉(zhuan)速(su)指風(feng)扇(shan)旋轉(zhuan)的速(su)度，通常以1分鐘(zhong)內轉(zhuan)動的圈(quan)數來衡量，即：rpm。轉(zhuan)速(su)與(yu)(yu)機電繞線(xian)匝數、線(xian)徑(jing)(jing)(jing)、扇(shan)葉(xie)葉(xie)輪外(wai)徑(jing)(jing)(jing)與(yu)(yu)底(di)徑(jing)(jing)(jing)，葉(xie)片形狀及所用軸承等因素(su)有(you)關，轉(zhuan)速(su)增(zeng)(zeng)大，風(feng)量相應增(zeng)(zeng)大。

轉(zhuan)(zhuan)速(su)值的大(da)(da)(da)小(xiao)，在一定程度上(shang)代表了(le)風(feng)(feng)(feng)量(liang)的大(da)(da)(da)小(xiao)，在條件一定時，轉(zhuan)(zhuan)速(su)越大(da)(da)(da)，則噪音及振動會相應加大(da)(da)(da)，因此，在風(feng)(feng)(feng)量(liang)滿足散(san)熱要求(qiu)的情況下(xia)，應盡量(liang)使用低(di)轉(zhuan)(zhuan)速(su)風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)。一般轉(zhuan)(zhuan)速(su)大(da)(da)(da)小(xiao)(以DC軸流(liu)風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)為(wei)例)：2510風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)7000～12000rpm；3010風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)5000～9000rpm；4010風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)5000～7000rpm；5010風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)3500～5000rpm；6025風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)2600～4500rpm；7025風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)2400～3600rpm；8025風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)2000～3500rpm；9225風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)1600～3100rpm；12025風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)1500～2500rpm；12038風(feng)(feng)(feng)扇(shan)(shan)(shan)(shan)(shan)2000～3200rpm。

風扇轉(zhuan)速(su)可(ke)在啟動電腦時通過BIOS測(ce)(ce)(ce)試(shi)(shi)，或通過其他(ta)主板(ban)自帶的(de)監控軟件測(ce)(ce)(ce)試(shi)(shi)；也可(ke)以通過轉(zhuan)速(su)測(ce)(ce)(ce)試(shi)(shi)儀測(ce)(ce)(ce)試(shi)(shi)。注(zhu)意：前兩種方式必須是支持測(ce)(ce)(ce)速(su)功能的(de)風扇才(cai)能測(ce)(ce)(ce)出。

風量與風壓：風量與風壓的測試(shi)(shi)方法(fa)有兩種(zhong)，一(yi)(yi)是(shi)用(yong)風洞儀測試(shi)(shi)，另一(yi)(yi)種(zhong)是(shi)用(yong)雙箱法(fa)測。但(dan)對于(yu)一(yi)(yi)般用(yong)戶而言，沒(mei)有這樣(yang)的設備。只能(neng)根據廠家提供的數據作為參(can)考，最終要看降溫(wen)效果。

風(feng)量(liang)(liang)：風(feng)量(liang)(liang)是(shi)(shi)(shi)指(zhi)風(feng)扇(shan)通風(feng)面(mian)(mian)(mian)(mian)積(ji)平(ping)(ping)面(mian)(mian)(mian)(mian)速(su)度之積(ji)。通風(feng)面(mian)(mian)(mian)(mian)積(ji)是(shi)(shi)(shi)出口面(mian)(mian)(mian)(mian)積(ji)減去渦舌處的投影(ying)面(mian)(mian)(mian)(mian)積(ji)。平(ping)(ping)面(mian)(mian)(mian)(mian)速(su)度是(shi)(shi)(shi)氣(qi)(qi)流(liu)通過整個平(ping)(ping)面(mian)(mian)(mian)(mian)的氣(qi)(qi)體運動(dong)速(su)度，單位是(shi)(shi)(shi)m3/s 。平(ping)(ping)面(mian)(mian)(mian)(mian)速(su)度一(yi)定時(shi),扇(shan)葉(xie)葉(xie)輪外徑越(yue)(yue)大(da)，通風(feng)面(mian)(mian)(mian)(mian)積(ji)越(yue)(yue)大(da)，風(feng)量(liang)(liang)則越(yue)(yue)大(da)。平(ping)(ping)面(mian)(mian)(mian)(mian)速(su)度由轉(zhuan)子的轉(zhuan)速(su)和(he)風(feng)壓決定。通風(feng)面(mian)(mian)(mian)(mian)積(ji)一(yi)定時(shi)，平(ping)(ping)面(mian)(mian)(mian)(mian)速(su)度越(yue)(yue)大(da)，風(feng)量(liang)(liang)越(yue)(yue)大(da)。風(feng)量(liang)(liang)越(yue)(yue)大(da)，空(kong)(kong)氣(qi)(qi)吸熱(re)(re)量(liang)(liang)則越(yue)(yue)大(da)，空(kong)(kong)氣(qi)(qi)流(liu)動(dong)轉(zhuan)移時(shi)能夠(gou)帶周能帶走更多的熱(re)(re)量(liang)(liang)，扇(shan)熱(re)(re)效果(guo)越(yue)(yue)明(ming)顯。

風(feng)(feng)壓(ya)(ya)：為(wei)(wei)進行正常通風(feng)(feng)，需(xu)要克服(fu)風(feng)(feng)扇(shan)通風(feng)(feng)行程內的(de)(de)(de)(de)阻(zu)力(li)，風(feng)(feng)扇(shan)必須產生克服(fu)送風(feng)(feng)阻(zu)力(li)的(de)(de)(de)(de)壓(ya)(ya)力(li)，測量到的(de)(de)(de)(de)壓(ya)(ya)力(li)的(de)(de)(de)(de)變化(hua)值稱為(wei)(wei)靜(jing)壓(ya)(ya)，即最大靜(jing)壓(ya)(ya)與大氣壓(ya)(ya)的(de)(de)(de)(de)差壓(ya)(ya)。它是(shi)氣體對平行于物體表面(mian)作用(yong)的(de)(de)(de)(de)壓(ya)(ya)力(li)，靜(jing)壓(ya)(ya)是(shi)通過垂(chui)直于其表面(mian)的(de)(de)(de)(de)孔測量出來的(de)(de)(de)(de)。把氣體流(liu)動(dong)中(zhong)所需(xu)要動(dong)能轉化(hua)為(wei)(wei)壓(ya)(ya)力(li)形式稱為(wei)(wei)動(dong)壓(ya)(ya)。

為(wei)實現(xian)送風(feng)(feng)(feng)的(de)(de)目的(de)(de)，需要有(you)靜壓(ya)(ya)(ya)(ya)和動(dong)壓(ya)(ya)(ya)(ya)。全(quan)壓(ya)(ya)(ya)(ya)為(wei)靜壓(ya)(ya)(ya)(ya)與動(dong)壓(ya)(ya)(ya)(ya)的(de)(de)代數和，全(quan)壓(ya)(ya)(ya)(ya)是(shi)指由(you)風(feng)(feng)(feng)扇(shan)(shan)所給(gei)定的(de)(de)的(de)(de)全(quan)壓(ya)(ya)(ya)(ya)增(zeng)加量(liang)(liang)，即風(feng)(feng)(feng)扇(shan)(shan)的(de)(de)出口(kou)和進口(kou)之(zhi)(zhi)間的(de)(de)全(quan)壓(ya)(ya)(ya)(ya)之(zhi)(zhi)差。在實際應(ying)用中，標稱的(de)(de)最(zui)大(da)(da)(da)風(feng)(feng)(feng)量(liang)(liang)值(zhi)并不是(shi)實際扇(shan)(shan)熱片得到的(de)(de)送風(feng)(feng)(feng)量(liang)(liang)，風(feng)(feng)(feng)量(liang)(liang)大(da)(da)(da)，并不代表通(tong)風(feng)(feng)(feng)能力強。因空氣流動(dong)時，氣流在其(qi)流動(dong)路徑會遇(yu)上(shang)扇(shan)(shan)熱稽片或元件的(de)(de)阻擾，其(qi)阻抗會限制空氣自由(you)流通(tong)。即風(feng)(feng)(feng)量(liang)(liang)增(zeng)大(da)(da)(da)時，風(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)會減(jian)小。因此必須有(you)一(yi)個最(zui)佳操(cao)作(zuo)工作(zuo)點(dian)，即風(feng)(feng)(feng)扇(shan)(shan)性能曲線(xian)(xian)與風(feng)(feng)(feng)阻曲線(xian)(xian)的(de)(de)交點(dian)。在工作(zuo)點(dian)，風(feng)(feng)(feng)扇(shan)(shan)特性曲線(xian)(xian)之(zhi)(zhi)斜率為(wei)最(zui)小，而系統特性曲線(xian)(xian)之(zhi)(zhi)變(bian)化(hua)率為(wei)最(zui)低。注意此時的(de)(de)風(feng)(feng)(feng)扇(shan)(shan)靜態效率(風(feng)(feng)(feng)量(liang)(liang)×風(feng)(feng)(feng)壓(ya)(ya)(ya)(ya)÷耗電)為(wei)最(zui)佳。 當然有(you)時為(wei)了能減(jian)少系統阻抗，甚至(zhi)選用尺寸較小的(de)(de)風(feng)(feng)(feng)扇(shan)(shan)，也(ye)可(ke)以獲(huo)得相同的(de)(de)風(feng)(feng)(feng)量(liang)(liang)。

風扇的軸承系統：

風扇的(de)(de)(de)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)系(xi)統一(yi)般建議最好選用(yong)滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)，因為扇(shan)(shan)(shan)熱(re)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)的(de)(de)(de)壽命(ming)通(tong)常取(qu)決(jue)于其軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)可(ke)(ke)靠(kao)性，滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)系(xi)統已被(bei)證實具有高(gao)(gao)效率與(yu)低(di)生熱(re)的(de)(de)(de)特(te)點(dian)。滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)屬滾(gun)(gun)(gun)動(dong)摩(mo)(mo)擦(ca)，由(you)金(jin)屬珠(zhu)(zhu)(zhu)(zhu)滾(gun)(gun)(gun)動(dong)，接觸(chu)面小(xiao)，摩(mo)(mo)擦(ca)系(xi)數小(xiao)；而(er)含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)為滑(hua)(hua)(hua)動(dong)摩(mo)(mo)擦(ca)，接觸(chu)面大(da)(da)，長期使(shi)(shi)(shi)用(yong)后，油(you)(you)會揮(hui)發，軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)容易磨(mo)損，摩(mo)(mo)擦(ca)系(xi)數大(da)(da)，后期噪(zao)音(yin)較大(da)(da)，壽命(ming)短。品質好的(de)(de)(de)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)除了(le)通(tong)風(feng)(feng)(feng)(feng)(feng)量大(da)(da)、風(feng)(feng)(feng)(feng)(feng)壓高(gao)(gao)以(yi)外，可(ke)(ke)靠(kao)性也是非(fei)常重要(yao)的(de)(de)(de)，風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)使(shi)(shi)(shi)用(yong)的(de)(de)(de)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)形式(shi)在此顯得(de)(de)非(fei)常重要(yao)。高(gao)(gao)速(su)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)一(yi)律(lv)使(shi)(shi)(shi)用(yong)滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(Ball bearing)而(er)低(di)速(su)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)則使(shi)(shi)(shi)用(yong)成(cheng)(cheng)本低(di)廉的(de)(de)(de)含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(Sleeve bearing)。含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)只用(yong)一(yi)個(ge)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)；而(er)滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)都需(xu)要(yao)兩個(ge)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)，單滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)，是“1 Ball + 1 Sleeve”，依(yi)然帶有含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)成(cheng)(cheng)分。比單滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)更(geng)高(gao)(gao)級的(de)(de)(de)是雙滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)，即Two Balls。含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)壽命(ming)一(yi)般為10000小(xiao)時，單滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)為30000小(xiao)時，雙滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)為50000小(xiao)時以(yi)上(環境溫度(du)均(jun)設定在25℃以(yi)下(xia)時)。風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)使(shi)(shi)(shi)用(yong)的(de)(de)(de)含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)由(you)銅基粉末燒結而(er)成(cheng)(cheng)，使(shi)(shi)(shi)用(yong)含(han)(han)油(you)(you)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)需(xu)加(jia)潤(run)滑(hua)(hua)(hua)油(you)(you)以(yi)減少滑(hua)(hua)(hua)動(dong)摩(mo)(mo)數,潤(run)滑(hua)(hua)(hua)油(you)(you)由(you)鋰基潤(run)滑(hua)(hua)(hua)脂加(jia)特(te)制機(ji)油(you)(you)調制而(er)成(cheng)(cheng)。隨(sui)著長時間(jian)的(de)(de)(de)運轉(zhuan)(zhuan)，軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)內的(de)(de)(de)機(ji)油(you)(you)會揮(hui)發而(er)變干，摩(mo)(mo)擦(ca)系(xi)數增大(da)(da)，風(feng)(feng)(feng)(feng)(feng)扇(shan)(shan)(shan)運轉(zhuan)(zhuan)受影響，可(ke)(ke)能出現異音(yin)，轉(zhuan)(zhuan)速(su)偏慢甚至(zhi)不轉(zhuan)(zhuan)現象。而(er)滾(gun)(gun)(gun)珠(zhu)(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)由(you)滾(gun)(gun)(gun)動(dong)摩(mo)(mo)擦(ca)取(qu)代了(le)滑(hua)(hua)(hua)動(dong)摩(mo)(mo)擦(ca)，摩(mo)(mo)擦(ca)系(xi)數小(xiao)并(bing)克服(fu)了(le)摩(mo)(mo)擦(ca)系(xi)數容易變的(de)(de)(de)缺點(dian)，因而(er)運轉(zhuan)(zhuan)穩定性強，壽命(ming)相對要(yao)長得(de)(de)多。