工作前泵內必須充以一定數量的工作水是水環式真空泵能(neng)夠(gou)工(gong)作(zuo)的(de)必(bi)要(yao)條(tiao)件(jian)。向(xiang)泵(beng)充(chong)入(ru)水(shui)後(hou)，當(dang)葉(ye)輪(lun)旋(xuan)轉(zhuan)時(shi)，水(shui)被(bei)帶(dai)動(dong)旋(xuan)轉(zhuan)，形(xing)成(cheng)一(yi)緊(jin)貼(tie)泵(beng)殼(ke)內(nei)壁(bi)的(de)水(shui)環(huan)，水(shui)環(huan)內(nei)表(biao)麵(mian)與(yu)葉(ye)輪(lun)輪(lun)毅(yi)表(biao)麵(mian)及(ji)兩(liang)側(ce)蓋(gai)端(duan)麵(mian)之(zhi)間(jian)形(xing)成(cheng)一(yi)個(ge)月(yue)牙(ya)形(xing)的(de)工(gong)作(zuo)空(kong)間(jian)。該(gai)空(kong)間(jian)被(bei)葉(ye)輪(lun)的(de)葉(ye)片(pian)分(fen)隔(ge)成(cheng)若(ruo)幹(gan)個(ge)互(hu)不(bu)相(xiang)通(tong)的(de)腔(qiang)室(shi)。這(zhe)些(xie)腔(qiang)室(shi)的(de)容(rong)積(ji)隨(sui)著(zhe)葉(ye)輪(lun)的(de)回(hui)轉(zhuan)將(jiang)會(hui)周(zhou)期(qi)性(xing)地(di)變(bian)大(da)和(he)變(bian)小(xiao)。顯(xian)然(ran)，腔(qiang)室(shi)容(rong)積(ji)變(bian)大(da)時(shi)將(jiang)吸(xi)入(ru)流(liu)體(ti)，腔(qiang)體(ti)容(rong)積(ji)變(bian)小(xiao)時(shi)將(jiang)會(hui)擠(ji)壓(ya)和(he)排(pai)出(chu)流(liu)體(ti)。吸(xi)入(ru)、壓縮和排出三個工作階段便組成了水環泵的一個工作循環。
以輸送氣體為例:
1)吸入過程—dangyejianzhuanguotuzhongdeyoubanzhuanshi，youyuyepianwaiduanyupianxindebengkejiandejulizengjia，yejiandeyetijiuhuibeishuaichu，shiyejianqiangshiderongjizhujianzengda，qitibiantongguocemiandexirukoubeixiru。
2)壓縮過程—dangyejianzhuanguoxirukoukaishijinrutushizuobanzhuanshi，youyubengkeyuyepianwaiduandejulizhujiansuoxiao，yelunwaianyuanzhoufangxianggaosuliudongdeyeliubianhuijiruyejian。zheyang，zaiyejianshangweiyupaichukouxiangtongshi，qizhongdeqitibianshoudaoyasuo。
3)排出過程—當dang葉ye間jian轉zhuan到dao與yu排pai出chu口kou相xiang通tong時shi，葉ye間jian腔qiang室shi中zhong的de壓ya力li即ji會hui在zai瞬shun間jian與yu排pai出chu壓ya力li相xiang平ping衡heng，並bing在zai葉ye輪lun隨sui後hou的de轉zhuan動dong過guo程cheng中zhong，由you於yu葉ye外wai的de液ye體ti不bu斷duan擠ji入ru葉ye間jian，從cong而er將jiang氣qi體ti排pai出chu。
可ke見jian，水shui環huan泵beng的de工gong作zuo原yuan理li與yu葉ye片pian泵beng有you非fei常chang相xiang似si之zhi處chu，即ji都dou是shi靠kao工gong作zuo腔qiang室shi的de容rong積ji變bian化hua來lai產chan生sheng吸xi排pai，但dan兩liang者zhe卻que有you著zhe重zhong要yao的de差cha別bie。水shui環huan泵beng中zhong的de定ding子zi是shi由you一yi個ge旋xuan轉zhuan水shui環huan構gou成cheng的de，而er這zhe個ge水shui環huan是shi由you葉ye輪lun給gei予yu工gong作zuo水shui的de動dong能neng所suo形xing成cheng的de。水shui環huan中zhong的de液ye體ti在zai圖tu示shi的de右you半ban轉zhuan中zhong是shi靠kao葉ye輪lun帶dai動dong其qi回hui轉zhuan而er獲huo得de了le一yi定ding的de能neng量liang，並bing被bei甩shuai到dao葉ye外wai的de流liu道dao中zhong;而er在zai其qi進jin入ru左zuo半ban轉zhuan後hou，也ye就jiu隻zhi能neng憑ping借jie其qi已yi獲huo得de的de動dong能neng擠ji入ru葉ye間jian，壓ya縮suo氣qi體ti。這zhe樣yang，葉ye輪lun外wai的de液ye體ti流liu速su必bi然ran會hui隨sui著zhe壓ya力li的de增zeng加jia而er降jiang低di。當dang排pai出chu壓ya力li升sheng高gao到dao一yi定ding的de數shu值zhi時shi，葉ye輪lun外wai液ye體ti的de速su度du也ye就jiu會hui降jiang到dao很hen低di，從cong而er不bu能neng進jin入ru葉ye間jian去qu壓ya縮suo氣qi體ti。也ye就jiu是shi說shuo，水shui環huan泵beng中zhong的de氣qi體ti在zai壓ya縮suo階jie段duan壓ya力li能neng的de增zeng加jia，完wan全quan是shi靠kao工gong作zuo水shui獲huo自zi葉ye輪lun的de動dong能neng轉zhuan換huan而er來lai的de。因yin此ci，水shui環huan泵beng的de排pai出chu壓ya力li不bu會hui像xiang其qi他ta容rong積ji式shi泵beng那na樣yang會hui隨sui排pai出chu負fu荷he增zeng加jia而er不bu斷duan增zeng加jia到dao危wei險xian的de程cheng度du，即ji水環泵的最高工作壓力(排出閥全關時的壓力)有限。
