1、旋片式真空泵
转(zhuan)子以(yi)一定的(de)(de)偏心距装在泵(beng)壳内并(bing)与泵(beng)壳内表面(mian)的(de)(de)固定面(mian)靠近,在转(zhuan)子槽内装有(you)(you)(you)两(liang)个(或两(liang)个以(yi)上)旋(xuan)(xuan)片(pian)(pian)(pian)(pian),当转(zhuan)子旋(xuan)(xuan)转(zhuan)时旋(xuan)(xuan)片(pian)(pian)(pian)(pian)能沿其(qi)径(jing)向槽往复滑(hua)动且与泵(beng)壳内壁始(shi)终接触,此旋(xuan)(xuan)片(pian)(pian)(pian)(pian)随转(zhuan)子一起(qi)旋(xuan)(xuan)转(zhuan),可(ke)将泵(beng)腔(qiang)分成几个可(ke)变容积(ji)。旋(xuan)(xuan)片(pian)(pian)(pian)(pian)式真(zhen)空(kong)(kong)(kong)泵(beng)属于(yu)低真(zhen)空(kong)(kong)(kong)泵(beng)。它可(ke)以(yi)单独使用(yong)(yong),也(ye)可(ke)以(yi)作为其(qi)他高真(zhen)空(kong)(kong)(kong)泵(beng)或超(chao)高真(zhen)空(kong)(kong)(kong)泵(beng)的(de)(de)前级泵(beng)。旋(xuan)(xuan)片(pian)(pian)(pian)(pian)泵(beng)多为中小型泵(beng),产品已经(jing)系(xi)列化。旋(xuan)(xuan)片(pian)(pian)(pian)(pian)泵(beng)有(you)(you)(you)单级和(he)双级两(liang)种,一般多做(zuo)成双级的(de)(de),以(yi)获得较高的(de)(de)真(zhen)空(kong)(kong)(kong)度。旋(xuan)(xuan)片(pian)(pian)(pian)(pian)泵(beng)绝大多数是单工(gong)作腔(qiang)结(jie)构,常(chang)用(yong)(yong)两(liang)个径(jing)向滑(hua)片(pian)(pian)(pian)(pian),也(ye)有(you)(you)(you)用(yong)(yong)三个斜(xie)置滑(hua)片(pian)(pian)(pian)(pian)的(de)(de)。贯穿滑(hua)片(pian)(pian)(pian)(pian)真(zhen)空(kong)(kong)(kong)泵(beng)也(ye)有(you)(you)(you)应(ying)用(yong)(yong)。
2、滑阀式真空泵
在(zai)偏(pian)心转(zhuan)(zhuan)子外(wai)部(bu)装有一个滑(hua)(hua)阀(fa),转(zhuan)(zhuan)子旋转(zhuan)(zhuan)带动(dong)滑(hua)(hua)阀(fa)沿泵壳内壁滑(hua)(hua)动(dong)和(he)滚动(dong),滑(hua)(hua)阀(fa)上部(bu)的(de)滑(hua)(hua)阀(fa)杆能在(zai)可摆动(dong)的(de)滑(hua)(hua)阀(fa)导(dao)轨中滑(hua)(hua)动(dong),而把泵腔(qiang)分成(cheng)两(liang)个可变容(rong)积。滑(hua)(hua)阀(fa)式真(zhen)空泵的(de)抽气原(yuan)理(li)与(yu)旋片泵相(xiang)似,但两(liang)者结(jie)构不同(tong)。滑(hua)(hua)阀(fa)式真(zhen)空泵是(shi)利用滑(hua)(hua)阀(fa)机构来改(gai)变吸气腔(qiang)容(rong)积的(de),故称滑(hua)(hua)阀(fa)泵。
3、定片式真空泵
在泵壳(qiao)内(nei)装有一个与泵内(nei)表面靠近的(de)偏心(xin)转(zhuan)(zhuan)子,泵壳(qiao)上(shang)装有一个始终与转(zhuan)(zhuan)子表面接(jie)触的(de)径向滑片,当转(zhuan)(zhuan)子旋(xuan)转(zhuan)(zhuan)时,滑片能上(shang)、下滑动将(jiang)泵腔分成两(liang)个可变(bian)容积。定(ding)片式真(zhen)空泵抽速较小(xiao),有单级、双级之分,双级泵的(de)极限真(zhen)空可达(da)10-1Pa。泵的(de)结构简单、使用寿(shou)命较长和(he)检(jian)修容易,但由于(yu)其工作性能不如旋(xuan)片泵,所以目前已经很少生(sheng)产和(he)应用。
4、余摆线式真空泵
在(zai)泵(beng)(beng)(beng)腔(qiang)(qiang)内偏(pian)心装(zhuang)有一个(ge)型线(xian)(xian)为余摆(bai)线(xian)(xian)的(de)转(zhuan)(zhuan)子(zi)(zi),它沿泵(beng)(beng)(beng)腔(qiang)(qiang)内壁转(zhuan)(zhuan)动并将泵(beng)(beng)(beng)腔(qiang)(qiang)分(fen)成两个(ge)可(ke)变容(rong)积。泵(beng)(beng)(beng)的(de)动平衡性好,所以(yi)泵(beng)(beng)(beng)运转(zhuan)(zhuan)较平稳、振动亦小,转(zhuan)(zhuan)速(su)可(ke)以(yi)提高(gao),可(ke)以(yi)做到(dao)尺寸小、抽速(su)大(da),适(shi)合发展为大(da)抽速(su)的(de)机械真空泵(beng)(beng)(beng)。由于吸气管路(lu)短而粗,有利于提高(gao)低压(ya)力下的(de)抽速(su)。因此,在(zai)低压(ya)范(fan)围内(1~l00Pa)余摆(bai)线(xian)(xian)泵(beng)(beng)(beng)的(de)抽速(su)特性曲(qu)线(xian)(xian)优于滑阀泵(beng)(beng)(beng)。余摆(bai)线(xian)(xian)泵(beng)(beng)(beng)的(de)转(zhuan)(zhuan)子(zi)(zi)和泵(beng)(beng)(beng)体是一对共轭齿形副的(de)啮合运动,所以(yi)对被抽气体中含(han)有一定量的(de)粉尘及小颗粒(li)等不(bu)太敏(min)感(gan)。余摆(bai)线(xian)(xian)泵(beng)(beng)(beng)适(shi)应较高(gao)温(wen)度的(de)工作环境,可(ke)以(yi)通过温(wen)控装(zhuang)置(zhi)使泵(beng)(beng)(beng)腔(qiang)(qiang)保持较高(gao)温(wen)度(即成为余摆(bai)线(xian)(xian)热泵(beng)(beng)(beng)),用来抽除(chu)大(da)量的(de)可(ke)凝性水蒸(zheng)汽。