【正文】 e force A=A1A2, the direction is ordinary and A1 same (general A2 is small).(2). Axial force balanced ①Uses double attracts the type impeller: The impeller lateral symmetry, the fluid from the both sides inspiration, the axial force automatic counterbalance achieves balanced.②Opens the balancing hole or installs the pensating pipe: A: Opens several balancing holes in the impeller wheel disk photograph well regarding the induction port place. B: After order to avoid the balancing hole, because the mainstream is disturbed increases the hydraulic loss, may suppose the pensating pipe to replace the balancing hole, namely uses an acorn tube leadingin point pressure to the wheel disk back side.③Uses the balanced leaf blade: Casts several radial direction muscle piece at the back of the leaf wheel disk, the  muscle piece drives at the back of the impeller in the gap fluid to accelerate to revolve, increases the centrifugal force, , thus causes at the back of the impeller the pressure obviously to reduce. ④Using thrust bearing withstanding axial force. Generally in the small single suction pump the thrust bearing may withstand the plete axial force, prevents the pump spindle to flee moves.Eighth. centrifugal pump39。s operating procedure 1. Centrifugal pump starts the inspection (1) Electrical machinery overhaul, before connecting the shaft coupling, inspects electrical machinery39。s rotation direction first to be whether correct. (2) inspection pumps out the inlet line and the attached pipeline, the flange, the valve installs whether to meet the requirement, foot bolt and grounding to be whether good, whether the shaft coupling does install.(3) jigger inspection, rotates whether normally.(4) inspection lubricating oil oil level is whether normal, refuels without the oil, and inspects the lubricating oil (fat) oil material nature.(5) turns on various cooling water valve, and inspects the pipeline to be whether unimpeded. Attention cooling water not suitable oversized or too small, will create the waste oversized, too small, then the cooling performance will be bad. Generally the cooling current of water bees the striation (6) dozen of pumping39。s inlet valve, closes pump39。s outlet valve, and turns on the pressure gauge valve. (7) inspection machine pump39。s seal condition and oil seal opening. attention: The hot oil pump wants evenly before the start preheating. 2. centrifugal pump39。s start (1) all operates the inlet valve, closes the outlet valve, the starting dynamo.(2), when the pump outlet pressure is bigger than the service pressure, inspects each work on six cylinders, turns on the outlet valve (3) starting dynamo, if the start or has time the unusual sound, should the dump inspection, after eliminating the breakdown, immediately only then (4) start, pays attention to the human not to face the shaft coupling, by against departs offends somebody.3. the centrifugal pump stops the pump to operate (1) to close pump39。s outlet valve slowly.(2) shuts off electrical machinery39。s power source. (3) closes the pressure gauge valve.(4) parking, cannot stop the cooling water immediately, should pump39。s temperature only then cut off the water supply falling to 80 degrees below. (5) according to the need, closes the inlet valve, the pump body blows off.4. centrifugal pump operates when matters needing attention (1) centrifugal pump when revolution avoids the idle operation. (2) avoids when closes the outlet valve the long time revolution. (3) refuses the water used battery (4) centrifugal pump must in close in outlet valve39。s situation to start.外文文獻(xiàn)二翻譯泵的概述泵是應(yīng)用非常廣泛的通用機(jī)械，可以說是液體流動(dòng)之處，幾乎都有泵在工作。而且，隨著科學(xué)技術(shù)的發(fā)展，泵的應(yīng)用領(lǐng)域正在迅速擴(kuò)大，根據(jù)國家統(tǒng)計(jì)，泵的耗電量都約占全國總發(fā)電量的1/5,可見泵是當(dāng)然的耗能大戶。因而,提高泵技術(shù)水平對(duì)節(jié)約能耗具有重要意義。 驅(qū)動(dòng)機(jī)通過泵軸帶動(dòng)葉輪旋轉(zhuǎn)產(chǎn)生離心力,在離心力作用下,液體沿葉片流道被甩向葉輪出口,液體經(jīng)蝸殼收集送入排出管。液體從葉輪獲得能量,使壓力能和速度能均增加,并依靠此能量將液體輸送到工作地點(diǎn)。在液體被甩向葉輪出口的同時(shí),葉輪入口中心處形成了低壓,在吸液罐和葉輪中心處的液體之間就產(chǎn)生了壓差,吸液罐中的液體在這個(gè)壓差作用下,不斷地經(jīng)吸入管路及泵的吸入室進(jìn)入葉輪中。二、離心泵的結(jié)構(gòu)及主要零部件一臺(tái)離心泵主要由泵體、葉輪、密封環(huán)、旋轉(zhuǎn)軸、軸封箱等部件組成,有些離心泵還裝有導(dǎo)輪、誘導(dǎo)輪、平衡盤等。 :即泵的殼體,包括吸入室和壓出室。 ①吸入室:它的作用是使液體均勻地流進(jìn)葉輪。 ②壓出室:它的作用是收集液體,并把它送入下級(jí)葉輪或?qū)蚺懦龉?與此同時(shí)降低液體的速度,使動(dòng)能進(jìn)一步變成壓力能。壓出室有蝸殼和導(dǎo)葉兩種形式。2．葉輪:它是離心泵內(nèi)傳遞能量給液體的唯一元件,葉輪用鍵固定于軸上，隨軸由原動(dòng)機(jī)帶動(dòng)旋轉(zhuǎn),通過葉片把原動(dòng)機(jī)的能量傳給液體。 葉輪分類:①按照液體流入分類：單吸葉輪（在葉輪的一側(cè)有一個(gè)入口）和雙吸葉輪（液體從葉輪的兩側(cè)對(duì)稱地流到葉輪流道中）。 ②按照液體相對(duì)于旋轉(zhuǎn)軸線的流動(dòng)方向分類：徑流式葉輪、軸流式葉輪和混流式葉輪。③按照葉輪的結(jié)構(gòu)形式分類:閉式葉輪、開式葉輪和半開式葉輪。 3．軸:是傳遞機(jī)械能的重要零件,原動(dòng)機(jī)的扭矩通過它傳給葉輪。泵軸是泵轉(zhuǎn)子的主要零件，軸上裝有葉輪、軸套、平衡盤等零件。泵軸靠兩端軸承支承，在泵中作高速回轉(zhuǎn)，因而泵軸要承載能力大、耐磨、耐腐蝕。泵軸的材料一般選用碳素鋼或合金鋼并經(jīng)調(diào)質(zhì)處理。:是安裝在轉(zhuǎn)動(dòng)的葉輪和靜止的泵殼（中段和導(dǎo)葉的組合件）之間的密封裝置。其作用是通過控制二者之間間隙的方法，增加泵內(nèi)高低壓腔之間液體流動(dòng)的阻力，減少泄漏。：軸套是用來保護(hù)泵軸的，使之不受腐蝕和磨損。必要時(shí)，軸套可以更換。：泵軸和前后端蓋間的填料函裝置簡稱為軸封，主要防止泵中的液體泄漏和空氣進(jìn)入泵中，以達(dá)到密封和防止進(jìn)氣引起泵氣蝕的目的。軸封的形式：即帶有骨架的橡膠密封、填料密封和機(jī)械密封。 . 17