電風扇工作原理及檢修
風扇的分類:
散熱風扇通(tong)常分為以(yi)下三類:
軸流(liu)式:氣流(liu)出口(kou)方向(xiang)(xiang)與軸心方向(xiang)(xiang)相同。
離(li)心(xin)式:利用(yong)離(li)心(xin)力作用(yong)將氣流沿著(zhu)葉片(pian)向外甩出。
混流(liu)式:擁有以上兩種氣流(liu)方式。
電風扇電路圖
以上是(shi)比較常見(jian)的家(jia)用(yong)電(dian)風扇的電(dian)路圖,從中我們也不難看出它的一些原理,但是(shi)現在電(dian)風扇產品越(yue)來越(yue)多(duo),其電(dian)路圖也越(yue)來越(yue)復(fu)雜,但是(shi)還是(shi)萬(wan)變不離其中。
電風扇工作原理
電(dian)風扇(shan)中(zhong)的電(dian)流是(shi)交流電(dian),主(zhu)要的工作原理就是(shi)通電(dian)線(xian)圈(quan)在(zai)磁場中(zhong)受力而轉動。電(dian)能(neng)轉化為機械能(neng),轉動風葉,同(tong)時由于(yu)線(xian)圈(quan)電(dian)阻,會(hui)產(chan)生一(yi)些熱能(neng),所以一(yi)般(ban)電(dian)風扇(shan)使用過久表面會(hui)熱。電(dian)風扇(shan)的原理比(bi)較簡單,一(yi)般(ban)在(zai)初中(zhong)的物理課程(cheng)上都(dou)會(hui)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)(dian)風扇(shan)本身的(de)原因可能包(bao)括了(le)風葉可能太(tai)久了(le),電(dian)(dian)(dian)機(ji)的(de)內阻變(bian)(bian)大,導(dao)致(zhi)(zhi)風葉無(wu)法(fa)正(zheng)常轉(zhuan)動;風扇(shan)過熱(re)(re)引(yin)起了(le)電(dian)(dian)(dian)機(ji)帶負(fu)載(zai)能力變(bian)(bian)差,導(dao)致(zhi)(zhi)無(wu)法(fa)轉(zhuan)動;電(dian)(dian)(dian)機(ji)內部的(de)保護(hu)裝置過熱(re)(re)短路;電(dian)(dian)(dian)風扇(shan)的(de)啟動電(dian)(dian)(dian)容容量變(bian)(bian)小(xiao);電(dian)(dian)(dian)風扇(shan)轉(zhuan)軸軸向間隙過大也會引(yin)發電(dian)(dian)(dian)風扇(shan)問題(ti)。
電風扇轉不動的修理方法
先(xian)檢查一(yi)下電(dian)風扇(shan)以外的問(wen)(wen)題是(shi)(shi)不是(shi)(shi)全(quan)部都弄(nong)妥當了(le);然后(hou)如果是(shi)(shi)風葉不轉(zhuan)的話(hua)就(jiu)關(guan)閉電(dian)源,在風葉轉(zhuan)動的軸(zhou)上面(mian)加一(yi)些潤滑油;其他的問(wen)(wen)題可能就(jiu)會涉及到更換(huan)軸(zhou)套、拆(chai)換(huan)電(dian)容、調整墊片(pian)、電(dian)線損(sun)壞更換(huan)電(dian)線等問(wen)(wen)題,一(yi)般不是(shi)(shi)專業的人員就(jiu)要請維(wei)修師傅(fu)來看(kan)一(yi)下了(le),不過一(yi)般也不是(shi)(shi)好(hao)大的問(wen)(wen)題,也花(hua)不了(le)多(duo)少錢(qian)。
散熱風扇的原理及性能
原理:風扇(shan)的(de)工作(zuo)原理是按能量轉化來實現的(de),即:電(dian)(dian)能→電(dian)(dian)磁能→機械(xie)能→動(dong)能。其電(dian)(dian)路原理一般分為(wei)多種形式,采用(yong)的(de)電(dian)(dian)路不同,風扇(shan)的(de)性能就(jiu)會有差(cha)異。
轉 速:轉(zhuan)速指風扇旋轉(zhuan)的(de)速度,通(tong)常以1分鐘(zhong)內轉(zhuan)動的(de)圈數來衡量,即:rpm。轉(zhuan)速與(yu)機電繞(rao)線(xian)匝數、線(xian)徑(jing)、扇葉葉輪外(wai)徑(jing)與(yu)底徑(jing),葉片形狀及所用軸承(cheng)等(deng)因素有關,轉(zhuan)速增大,風量相應(ying)增大。
轉(zhuan)速值(zhi)的(de)大(da)小(xiao),在(zai)一(yi)定(ding)程度(du)上代表了風(feng)(feng)(feng)量(liang)的(de)大(da)小(xiao),在(zai)條件一(yi)定(ding)時,轉(zhuan)速越大(da),則噪音(yin)及振動會相應(ying)加大(da),因(yin)此,在(zai)風(feng)(feng)(feng)量(liang)滿足散熱要求(qiu)的(de)情況下,應(ying)盡量(liang)使用低轉(zhuan)速風(feng)(feng)(feng)扇(shan)(shan)。一(yi)般轉(zhuan)速大(da)小(xiao)(以DC軸流風(feng)(feng)(feng)扇(shan)(shan)為例):2510風(feng)(feng)(feng)扇(shan)(shan)7000~12000rpm;3010風(feng)(feng)(feng)扇(shan)(shan)5000~9000rpm;4010風(feng)(feng)(feng)扇(shan)(shan)5000~7000rpm;5010風(feng)(feng)(feng)扇(shan)(shan)3500~5000rpm;6025風(feng)(feng)(feng)扇(shan)(shan)2600~4500rpm;7025風(feng)(feng)(feng)扇(shan)(shan)2400~3600rpm;8025風(feng)(feng)(feng)扇(shan)(shan)2000~3500rpm;9225風(feng)(feng)(feng)扇(shan)(shan)1600~3100rpm;12025風(feng)(feng)(feng)扇(shan)(shan)1500~2500rpm;12038風(feng)(feng)(feng)扇(shan)(shan)2000~3200rpm。
風(feng)扇轉(zhuan)速可在(zai)啟動電(dian)腦時通(tong)(tong)過BIOS測試(shi)(shi),或(huo)通(tong)(tong)過其他主板(ban)自(zi)帶的監(jian)控軟件測試(shi)(shi);也可以通(tong)(tong)過轉(zhuan)速測試(shi)(shi)儀測試(shi)(shi)。注意(yi):前兩種方式必(bi)須是支持測速功(gong)能的風(feng)扇才(cai)能測出(chu)。
風量與風壓:風量與風壓的(de)測試(shi)方法有兩種(zhong),一(yi)是用(yong)風洞儀測試(shi),另一(yi)種(zhong)是用(yong)雙箱法測。但對于一(yi)般(ban)用(yong)戶而言(yan),沒有這樣的(de)設(she)備。只能(neng)根據廠家提(ti)供的(de)數(shu)據作為(wei)參考(kao),最(zui)終要看降溫效果。
風(feng)(feng)(feng)量(liang)(liang):風(feng)(feng)(feng)量(liang)(liang)是(shi)指(zhi)風(feng)(feng)(feng)扇(shan)(shan)通(tong)風(feng)(feng)(feng)面(mian)(mian)積(ji)平(ping)(ping)面(mian)(mian)速度(du)之(zhi)積(ji)。通(tong)風(feng)(feng)(feng)面(mian)(mian)積(ji)是(shi)出口面(mian)(mian)積(ji)減去渦舌處(chu)的(de)投影面(mian)(mian)積(ji)。平(ping)(ping)面(mian)(mian)速度(du)是(shi)氣流通(tong)過整個平(ping)(ping)面(mian)(mian)的(de)氣體運動速度(du),單位是(shi)m3/s 。平(ping)(ping)面(mian)(mian)速度(du)一定時(shi),扇(shan)(shan)葉葉輪外徑越(yue)大,通(tong)風(feng)(feng)(feng)面(mian)(mian)積(ji)越(yue)大,風(feng)(feng)(feng)量(liang)(liang)則越(yue)大。平(ping)(ping)面(mian)(mian)速度(du)由轉(zhuan)子的(de)轉(zhuan)速和風(feng)(feng)(feng)壓決定。通(tong)風(feng)(feng)(feng)面(mian)(mian)積(ji)一定時(shi),平(ping)(ping)面(mian)(mian)速度(du)越(yue)大,風(feng)(feng)(feng)量(liang)(liang)越(yue)大。風(feng)(feng)(feng)量(liang)(liang)越(yue)大,空(kong)氣吸(xi)熱量(liang)(liang)則越(yue)大,空(kong)氣流動轉(zhuan)移時(shi)能(neng)夠帶周能(neng)帶走更多的(de)熱量(liang)(liang),扇(shan)(shan)熱效果越(yue)明顯。
風(feng)壓(ya)(ya)(ya)(ya):為(wei)(wei)進行(xing)正(zheng)常通(tong)(tong)風(feng),需要克服(fu)風(feng)扇通(tong)(tong)風(feng)行(xing)程內的(de)(de)阻力(li),風(feng)扇必須產生(sheng)克服(fu)送(song)風(feng)阻力(li)的(de)(de)壓(ya)(ya)(ya)(ya)力(li),測量到的(de)(de)壓(ya)(ya)(ya)(ya)力(li)的(de)(de)變化(hua)值稱為(wei)(wei)靜(jing)壓(ya)(ya)(ya)(ya),即(ji)最大靜(jing)壓(ya)(ya)(ya)(ya)與大氣(qi)(qi)壓(ya)(ya)(ya)(ya)的(de)(de)差(cha)壓(ya)(ya)(ya)(ya)。它是(shi)(shi)氣(qi)(qi)體(ti)對平(ping)行(xing)于物(wu)體(ti)表面作用的(de)(de)壓(ya)(ya)(ya)(ya)力(li),靜(jing)壓(ya)(ya)(ya)(ya)是(shi)(shi)通(tong)(tong)過垂(chui)直于其表面的(de)(de)孔測量出(chu)來的(de)(de)。把氣(qi)(qi)體(ti)流動中所需要動能轉化(hua)為(wei)(wei)壓(ya)(ya)(ya)(ya)力(li)形式(shi)稱為(wei)(wei)動壓(ya)(ya)(ya)(ya)。
為(wei)(wei)實現送(song)風(feng)(feng)的(de)(de)(de)目的(de)(de)(de),需要有靜壓(ya)(ya)(ya)和(he)動(dong)壓(ya)(ya)(ya)。全壓(ya)(ya)(ya)為(wei)(wei)靜壓(ya)(ya)(ya)與動(dong)壓(ya)(ya)(ya)的(de)(de)(de)代(dai)數和(he),全壓(ya)(ya)(ya)是(shi)指由風(feng)(feng)扇(shan)(shan)所給定(ding)的(de)(de)(de)的(de)(de)(de)全壓(ya)(ya)(ya)增(zeng)加量(liang),即(ji)風(feng)(feng)扇(shan)(shan)的(de)(de)(de)出口和(he)進口之(zhi)(zhi)間的(de)(de)(de)全壓(ya)(ya)(ya)之(zhi)(zhi)差。在(zai)實際應(ying)用中,標稱的(de)(de)(de)最(zui)(zui)(zui)大風(feng)(feng)量(liang)值并不(bu)是(shi)實際扇(shan)(shan)熱(re)片得到的(de)(de)(de)送(song)風(feng)(feng)量(liang),風(feng)(feng)量(liang)大,并不(bu)代(dai)表(biao)通(tong)風(feng)(feng)能(neng)(neng)力(li)強(qiang)。因空氣流(liu)動(dong)時(shi)(shi),氣流(liu)在(zai)其流(liu)動(dong)路徑會遇(yu)上扇(shan)(shan)熱(re)稽片或元件的(de)(de)(de)阻擾,其阻抗(kang)會限制空氣自(zi)由流(liu)通(tong)。即(ji)風(feng)(feng)量(liang)增(zeng)大時(shi)(shi),風(feng)(feng)壓(ya)(ya)(ya)會減(jian)小(xiao)(xiao)。因此(ci)必須有一個最(zui)(zui)(zui)佳(jia)操作工作點(dian)(dian),即(ji)風(feng)(feng)扇(shan)(shan)性能(neng)(neng)曲線(xian)與風(feng)(feng)阻曲線(xian)的(de)(de)(de)交點(dian)(dian)。在(zai)工作點(dian)(dian),風(feng)(feng)扇(shan)(shan)特(te)性曲線(xian)之(zhi)(zhi)斜率(lv)為(wei)(wei)最(zui)(zui)(zui)小(xiao)(xiao),而系(xi)統特(te)性曲線(xian)之(zhi)(zhi)變(bian)化率(lv)為(wei)(wei)最(zui)(zui)(zui)低。注意(yi)此(ci)時(shi)(shi)的(de)(de)(de)風(feng)(feng)扇(shan)(shan)靜態效率(lv)(風(feng)(feng)量(liang)×風(feng)(feng)壓(ya)(ya)(ya)÷耗電(dian))為(wei)(wei)最(zui)(zui)(zui)佳(jia)。 當然有時(shi)(shi)為(wei)(wei)了(le)能(neng)(neng)減(jian)少系(xi)統阻抗(kang),甚至選(xuan)用尺寸較小(xiao)(xiao)的(de)(de)(de)風(feng)(feng)扇(shan)(shan),也可以(yi)獲得相(xiang)同的(de)(de)(de)風(feng)(feng)量(liang)。
風扇的軸承系統:
風扇的(de)(de)(de)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)系(xi)統(tong)(tong)一(yi)般(ban)建議最好選用滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng),因為(wei)扇(shan)(shan)(shan)熱(re)風(feng)扇(shan)(shan)(shan)的(de)(de)(de)壽命通常(chang)取決于其(qi)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)可靠(kao)性(xing),滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)系(xi)統(tong)(tong)已(yi)被證(zheng)實具有高(gao)效率與(yu)低(di)生(sheng)熱(re)的(de)(de)(de)特點。滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)屬滾(gun)動(dong)(dong)摩(mo)(mo)擦(ca),由(you)金屬珠(zhu)(zhu)(zhu)滾(gun)動(dong)(dong),接觸(chu)面小,摩(mo)(mo)擦(ca)系(xi)數(shu)小;而(er)(er)含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)為(wei)滑(hua)動(dong)(dong)摩(mo)(mo)擦(ca),接觸(chu)面大,長(chang)期(qi)使(shi)(shi)用后,油(you)(you)(you)會揮(hui)發,軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)容易(yi)磨損,摩(mo)(mo)擦(ca)系(xi)數(shu)大,后期(qi)噪音(yin)較大,壽命短。品質好的(de)(de)(de)風(feng)扇(shan)(shan)(shan)除了(le)通風(feng)量大、風(feng)壓高(gao)以外,可靠(kao)性(xing)也是(shi)非常(chang)重(zhong)要的(de)(de)(de),風(feng)扇(shan)(shan)(shan)使(shi)(shi)用的(de)(de)(de)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)形式在(zai)此顯得(de)非常(chang)重(zhong)要。高(gao)速(su)風(feng)扇(shan)(shan)(shan)一(yi)律(lv)使(shi)(shi)用滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(Ball bearing)而(er)(er)低(di)速(su)風(feng)扇(shan)(shan)(shan)則(ze)使(shi)(shi)用成本低(di)廉的(de)(de)(de)含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)(Sleeve bearing)。含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)風(feng)扇(shan)(shan)(shan)只用一(yi)個軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng);而(er)(er)滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)風(feng)扇(shan)(shan)(shan)都(dou)需要兩個軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng),單滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng),是(shi)“1 Ball + 1 Sleeve”,依然(ran)帶有含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)成分(fen)。比(bi)單滾(gun)珠(zhu)(zhu)(zhu)更高(gao)級的(de)(de)(de)是(shi)雙滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng),即Two Balls。含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)壽命一(yi)般(ban)為(wei)10000小時,單滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)為(wei)30000小時,雙滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)為(wei)50000小時以上(環境溫度均設定在(zai)25℃以下時)。風(feng)扇(shan)(shan)(shan)使(shi)(shi)用的(de)(de)(de)含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)由(you)銅基(ji)粉末燒(shao)結而(er)(er)成,使(shi)(shi)用含油(you)(you)(you)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)需加潤滑(hua)油(you)(you)(you)以減少滑(hua)動(dong)(dong)摩(mo)(mo)數(shu),潤滑(hua)油(you)(you)(you)由(you)鋰基(ji)潤滑(hua)脂(zhi)加特制機油(you)(you)(you)調(diao)制而(er)(er)成。隨著長(chang)時間的(de)(de)(de)運(yun)轉(zhuan),軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)內的(de)(de)(de)機油(you)(you)(you)會揮(hui)發而(er)(er)變干(gan),摩(mo)(mo)擦(ca)系(xi)數(shu)增大,風(feng)扇(shan)(shan)(shan)運(yun)轉(zhuan)受(shou)影響,可能出現異(yi)音(yin),轉(zhuan)速(su)偏(pian)慢甚至(zhi)不轉(zhuan)現象。而(er)(er)滾(gun)珠(zhu)(zhu)(zhu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)(cheng)(cheng)由(you)滾(gun)動(dong)(dong)摩(mo)(mo)擦(ca)取代了(le)滑(hua)動(dong)(dong)摩(mo)(mo)擦(ca),摩(mo)(mo)擦(ca)系(xi)數(shu)小并克服了(le)摩(mo)(mo)擦(ca)系(xi)數(shu)容易(yi)變的(de)(de)(de)缺(que)點,因而(er)(er)運(yun)轉(zhuan)穩定性(xing)強(qiang),壽命相對要長(chang)得(de)多。