?旋片式(shi)(shi)真(zhen)空泵(beng)(簡稱旋片式(shi)(shi)真(zhen)空泵(beng))是(shi)一(yi)種油封機械真(zhen)空泵(beng)。其工(gong)(gong)作壓力范圍(wei)為(wei)101325~1.33× 10-2(Pa)是(shi)低(di)真(zhen)空泵(beng)。它可以單獨使用,也可以作為(wei)其他高真(zhen)空泵(beng)或超(chao)高真(zhen)空泵(beng)的(de)前級泵(beng)使用。廣(guang)泛(fan)應用于冶金,機械,軍工(gong)(gong),電子,化工(gong)(gong),輕工(gong)(gong),石(shi)油,醫藥(yao)等生產和科研部門。
旋片式真(zhen)空泵可(ke)以去除(chu)密封容(rong)器(qi)中的干燥氣(qi)(qi)體(ti),并(bing)且如(ru)果(guo)安裝氣(qi)(qi)鎮裝置(zhi),則可(ke)以去除(chu)一定(ding)量的可(ke)冷(leng)凝氣(qi)(qi)體(ti)。但是,它不(bu)適(shi)合去除(chu)氧氣(qi)(qi)過高,對金屬有腐蝕性(xing),對泵油有化學反(fan)應性(xing),并(bing)含有微(wei)粒(li)粉(fen)塵的氣(qi)(qi)體(ti)。
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旋片式真(zhen)空泵(beng)(beng)是真(zhen)空技(ji)術中(zhong)最(zui)基本的(de)真(zhen)空采集設備之(zhi)一。旋片式真(zhen)空泵(beng)(beng)主要(yao)是中(zhong)小(xiao)型泵(beng)(beng)。旋片式真(zhen)空泵(beng)(beng)有單級(ji)(ji)和雙級(ji)(ji)兩(liang)(liang)種。所謂的(de)兩(liang)(liang)級(ji)(ji)是將(jiang)兩(liang)(liang)個串聯的(de)單級(ji)(ji)泵(beng)(beng)連接(jie)起來。通常,將(jiang)其制成兩(liang)(liang)個階段以獲(huo)得(de)更(geng)高的(de)真(zhen)空度(du)。?
旋片式(shi)真空泵(beng)的抽速與入口壓力之間的關(guan)系如下:在入口壓力為1333P.
a,1.33Pa和1.33× 10-1(Pa)時,抽速(su)值(zhi)不應為(wei)低于泵(beng)的標稱(cheng)抽速(su)的95%,50%和20%。?
旋(xuan)(xuan)(xuan)(xuan)片(pian)(pian)真空泵(beng)主(zhu)要由(you)泵(beng)體,轉(zhuan)子(zi),旋(xuan)(xuan)(xuan)(xuan)片(pian)(pian),端(duan)蓋(gai)和(he)彈簧組成。轉(zhuan)子(zi)偏心地安(an)裝在旋(xuan)(xuan)(xuan)(xuan)片(pian)(pian)式真空泵(beng)的(de)(de)空腔中(zhong),轉(zhuan)子(zi)的(de)(de)外圓周與泵(beng)室的(de)(de)內(nei)(nei)表面相切(兩者之間存在小(xiao)的(de)(de)間隙),并且(qie)兩個轉(zhuan)子(zi)葉(xie)片(pian)(pian)安(an)裝在轉(zhuan)子(zi)中(zhong)插槽。當旋(xuan)(xuan)(xuan)(xuan)轉(zhuan)時,旋(xuan)(xuan)(xuan)(xuan)轉(zhuan)葉(xie)片(pian)(pian)的(de)(de)頂端(duan)通過離心力和(he)彈簧的(de)(de)張力保持(chi)與泵(beng)室的(de)(de)內(nei)(nei)壁(bi)接觸,并且(qie)轉(zhuan)子(zi)的(de)(de)旋(xuan)(xuan)(xuan)(xuan)轉(zhuan)驅(qu)動(dong)旋(xuan)(xuan)(xuan)(xuan)轉(zhuan)葉(xie)片(pian)(pian)沿著(zhu)內(nei)(nei)壁(bi)滑動(dong)。
兩個(ge)旋轉(zhuan)葉片(pian)將(jiang)由轉(zhuan)子,泵腔和兩個(ge)端蓋包圍的(de)月牙形空(kong)(kong)間(jian)分成三個(ge)部分A,B和C,如圖所示。當轉(zhuan)子沿箭頭方向旋轉(zhuan)時(shi),與(yu)吸(xi)入口連通(tong)(tong)的(de)空(kong)(kong)間(jian)A的(de)容積逐(zhu)漸(jian)(jian)增大,并(bing)(bing)(bing)且處(chu)于(yu)抽吸(xi)過(guo)(guo)程中(zhong)(zhong)。與(yu)排(pai)(pai)氣(qi)(qi)(qi)(qi)口連通(tong)(tong)的(de)空(kong)(kong)間(jian)C的(de)容積逐(zhu)漸(jian)(jian)減(jian)小,并(bing)(bing)(bing)且處(chu)于(yu)排(pai)(pai)氣(qi)(qi)(qi)(qi)過(guo)(guo)程中(zhong)(zhong)。中(zhong)(zhong)心空(kong)(kong)間(jian)B的(de)體(ti)(ti)(ti)積也逐(zhu)漸(jian)(jian)減(jian)小并(bing)(bing)(bing)且處(chu)于(yu)壓縮(suo)過(guo)(guo)程中(zhong)(zhong)。由于(yu)空(kong)(kong)間(jian)A的(de)容積逐(zhu)漸(jian)(jian)增加(jia)(即,膨脹),氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)壓力(li)降低,并(bing)(bing)(bing)且泵入口處(chu)的(de)外部氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)壓力(li)強于(yu)空(kong)(kong)間(jian)A中(zhong)(zhong)的(de)壓力(li),從而吸(xi)入氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)。當空(kong)(kong)間(jian)A與(yu)吸(xi)入口隔(ge)離時(shi),即與(yu)空(kong)(kong)間(jian)B的(de)位置隔(ge)開時(shi),氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)開始被壓縮(suo),體(ti)(ti)(ti)積逐(zhu)漸(jian)(jian)減(jian)小,最(zui)后與(yu)排(pai)(pai)氣(qi)(qi)(qi)(qi)口連通(tong)(tong)。當壓縮(suo)氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)超過(guo)(guo)排(pai)(pai)氣(qi)(qi)(qi)(qi)壓力(li)時(shi),排(pai)(pai)氣(qi)(qi)(qi)(qi)閥被壓縮(suo)氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)推開,氣(qi)(qi)(qi)(qi)體(ti)(ti)(ti)通(tong)(tong)過(guo)(guo)油箱中(zhong)(zhong)的(de)油層排(pai)(pai)放(fang)到大氣(qi)(qi)(qi)(qi)中(zhong)(zhong)。
旋(xuan)片式真空泵(beng)的連(lian)續操(cao)作實現了(le)連(lian)續泵送(song)的目的。如果排出的氣(qi)(qi)體(ti)通過空(kong)氣(qi)(qi)通道并轉移到(dao)另一個階段(低真空(kong)水平),則它被低真空(kong)階段抽走,然(ran)后(hou)被低真空(kong)階段壓縮并排放到(dao)大(da)氣(qi)(qi)中,這構成了(le)雙極泵。這時總(zong)的壓縮比由兩(liang)級來負(fu)擔(dan),因而提高了(le)極限真空(kong)度(du)。