中高壓外嚙合齒輪泵畢業(yè)設(shè)計(jì)外文文獻(xiàn)(共18頁(yè))

1、精選優(yōu)質(zhì)文檔-傾情為你奉上武漢科技大學(xué)本科畢業(yè)設(shè)計(jì)（外文文獻(xiàn)） 題 目： 中高壓外嚙合齒輪泵設(shè)計(jì) 姓 名： 專 業(yè)： 交通運(yùn)輸 學(xué) 號(hào)： 指導(dǎo)教師： 專心-專注-專業(yè)外文文獻(xiàn)一 The concept of gear pump is very simple, that it is two of the most basic form of the same size gear in a close co-operation of mutual engagement with the rotating shell, the shell's internal similar "8

2、" shape, the two gears mounted inside , the diameter of gear and work closely with both sides and shell. From the extruder the material inhaled into the mouth of two intermediate gears, and full of the space, with the teeth along the shell of the rotary movement, the final two hours from the me

3、shing teeth. Speaking in terms of gear, also known as positive displacement pump device, that is, inside the cylinder like a piston, when a tooth to another tooth space of the fluid, the liquid was squeezed mechanically to row out. Because the liquid is incompressible, so the liquid and the tooth at

4、 the same time will not be able to occupy the same space, so that the liquid has been ruled out. Because of the constant mesh gear, this phenomenon occurs on a row and, therefore, the pump provides a continuous export to exclude the amount of a turn each pump, the volume of discharge is the same. Wi

5、th the continuous rotation of the driveshaft, pump fluid is continuously discharged. Pump flow directly to the speed of the pump. In fact, there is little pump of the fluid loss, which makes the operation of pumps can not achieve 100% efficiency, as these fluids are used to on both sides of bearing

6、and gear lubrication, and the pump body is also not possible with no gap, it can not be so that 100% of fluid discharged from the export, so a small amount of fluid loss is inevitable. However, a good pump can be run out of material for the majority, will still be able to achieve 93% 98% efficiency.

7、 For the viscosity or density change in the process fluid, the pump will not be affected too much. If there is a damper, for example, in the export side, one row or a limiter filter, pumps will push fluid through them. If the damper changes in their work, that is, if the filters become dirty, blocke

8、d, or limiter on the back of the hypertension, the pump will maintain a constant flow, until the device in the weakest parts of the mechanical limit (usually equipped with a torque limiter). For a pump speed, in fact, there are restrictions, which mainly depends on the process fluid, if the transmis

9、sion is oil, pump can rotate at high speed, but when the fluid is a high viscosity of the polymer melt, such restrictions will be significantly reduced.Promote blood flow into the intake side of the two tooth space is very important, if not fill in this space is full, the pump will not be able to di

10、scharge the flow of accurate, so the value of PV (pressure × velocity) is also a limiting factor, and is a process variable. As a result of these restrictions, gear pump manufacturers will provide a range of products, that is, different specifications and emission (per week to the emission of v

11、olume). These pumps will fit the specific application of technology to enable the system to achieve optimal capacity and price. PEP-II pump shaft gear and a total of one species hardened using technology, will be a longer working life. "D"-type bearing a combination of forced lubrication m

12、echanism, so that the polymer surface by the bearing, and return to the import side of pump to ensure effective lubrication of the rotation axis. This feature reduces the degradation of polymers and the possibility of being stranded. Precision machining of the pump body can "D"-type gear s

13、haft with precision bearings to ensure non-eccentric gear shaft to prevent gear wear. Structure and Parkool PTFE sealing lip sealed water-cooled sealed together. This shaft seal does not actually contact the surface, it is the principle of the sealing polymer to a semi-molten state cooling and the f

14、ormation of self-sealing. Can also be used Rheoseal sealing, seal it inside the table are reverse spiral groove processing, the polymer can be imported back to the anti-pressure. In order to facilitate the installation, the manufacturer has designed the installation of a ring bolt, so that the flang

15、e and install other equipment line, which makes the manufacture of tube flange easier. PEP-II with a gear pump with the pump to match the specifications of the heating elements for the user matching, which ensures rapid heating and heat control. Heating the body and pump in different ways, the damag

16、e to these components is limited to a board, the pump has nothing to do with the whole. Gear pump by an independent motor drive, to be effective in blocking the upper reaches of the pressure pulsation and flow fluctuations. Gear pump in the outlet of the pressure fluctuation can be controlled within

17、 1%. In the extrusion production line using a gear pump, can increase the output flow rate of material in the extruder to reduce the shear and residence time to reduce the extrusion temperature and pressure fluctuation in order to enhance productivity and product quality.外文文獻(xiàn)一翻譯齒輪泵的概念是很簡(jiǎn)單的，即它的最基本形式就

18、是兩個(gè)尺寸相同的齒輪在一個(gè)緊密配合的殼體內(nèi)相互嚙合旋轉(zhuǎn)，這個(gè)殼體的內(nèi)部類似“8”字形，兩個(gè)齒輪裝在里面，齒輪的外徑及兩側(cè)與殼體緊密配合。來自于擠出機(jī)的物料在吸入口進(jìn)入兩個(gè)齒輪中間，并充滿這一空間，隨著齒的旋轉(zhuǎn)沿殼體運(yùn)動(dòng)，最后在兩齒嚙合時(shí)排出。 在術(shù)語(yǔ)上講，齒輪泵也叫正排量裝置，即像一個(gè)缸筒內(nèi)的活塞，當(dāng)一個(gè)齒進(jìn)入另一個(gè)齒的流體空間時(shí)，液體就被機(jī)械性地?cái)D排出來。因?yàn)橐后w是不可壓縮的，所以液體和齒就不能在同一時(shí)間占據(jù)同一空間，這樣，液體就被排除了。由于齒的不斷嚙合，這一現(xiàn)象就連續(xù)在發(fā)生，因而也就在泵的出口提供了一個(gè)連續(xù)排除量，泵每轉(zhuǎn)一轉(zhuǎn)，排出的量是一樣的。隨著驅(qū)動(dòng)軸的不間斷地旋轉(zhuǎn)，泵也就不間斷地排出

19、流體。泵的流量直接與泵的轉(zhuǎn)速有關(guān)。 實(shí)際上，在泵內(nèi)有很少量的流體損失，這使泵的運(yùn)行效率不能達(dá)到100，因?yàn)檫@些流體被用來潤(rùn)滑軸承及齒輪兩側(cè)，而泵體也絕不可能無(wú)間隙配合，故不能使流體100地從出口排出，所以少量的流體損失是必然的。然而泵還是可以良好地運(yùn)行，對(duì)大多數(shù)擠出物料來說，仍可以達(dá)到9398的效率。 對(duì)于粘度或密度在工藝中有變化的流體，這種泵不會(huì)受到太多影響。如果有一個(gè)阻尼器，比如在排出口側(cè)放一個(gè)濾網(wǎng)或一個(gè)限制器，泵則會(huì)推動(dòng)流體通過它們。如果這個(gè)阻尼器在工作中變化，亦即如果濾網(wǎng)變臟、堵塞了，或限制器的背壓升高了，則泵仍將保持恒定的流量，直至達(dá)到裝置中最弱的部件的機(jī)械極限(通常裝有一個(gè)扭矩限制

20、器)。 對(duì)于一臺(tái)泵的轉(zhuǎn)速，實(shí)際上是有限制的，這主要取決于工藝流體，如果傳送的是油類，泵則能以很高的速度轉(zhuǎn)動(dòng)，但當(dāng)流體是一種高粘度的聚合物熔體時(shí)，這種限制就會(huì)大幅度降低。 推動(dòng)高粘流體進(jìn)入吸入口一側(cè)的兩齒空間是非常重要的，如果這一空間沒有填充滿，則泵就不能排出準(zhǔn)確的流量，所以PV值(壓力×流速)也是另外一個(gè)限制因素，而且是一個(gè)工藝變量。由于這些限制，齒輪泵制造商將提供一系列產(chǎn)品，即不同的規(guī)格及排量(每轉(zhuǎn)一周所排出的量)。這些泵將與具體的應(yīng)用工藝相配合，以使系統(tǒng)能力及價(jià)格達(dá)到最優(yōu)。 PEPII泵的齒輪與軸共為一體，采用通體淬硬工藝，可獲得更長(zhǎng)的工作壽命?！癉”型軸承結(jié)合了強(qiáng)制潤(rùn)滑機(jī)理，使

21、聚合物經(jīng)軸承表面，并返回到泵的進(jìn)口側(cè)，以確保旋轉(zhuǎn)軸的有效潤(rùn)滑。這一特性減少了聚合物滯留并降解的可能性。精密加工的泵體可使“D”型軸承與齒輪軸精確配合，確保齒輪軸不偏心，以防齒輪磨損。Parkool密封結(jié)構(gòu)與聚四氟唇型密封共同構(gòu)成水冷密封。這種密封實(shí)際上并不接觸軸的表面，它的密封原理是將聚合物冷卻到半熔融狀態(tài)而形成自密封。也可以采用Rheoseal密封，它在軸封內(nèi)表上加工有反向螺旋槽，可使聚合物被反壓回到進(jìn)口。為便于安裝，制造商設(shè)計(jì)了一個(gè)環(huán)形螺栓安裝面，以使與其它設(shè)備的法蘭安裝相配合，這使得筒形法蘭的制造更容易。 PEPII齒輪泵帶有與泵的規(guī)格相匹配的加熱元件，可供用戶選配，這可保證快速加溫和熱

22、量控制。與泵體內(nèi)加熱方式不同，這些元件的損壞只限于一個(gè)板子上，與整個(gè)泵無(wú)關(guān)。 齒輪泵由一個(gè)獨(dú)立的電機(jī)驅(qū)動(dòng)，可有效地阻斷上游的壓力脈動(dòng)及流量波動(dòng)。在齒輪泵出口處的壓力脈動(dòng)可以控制在1以內(nèi)。在擠出生產(chǎn)線上采用一臺(tái)齒輪泵，可以提高流量輸出速度，減少物料在擠出機(jī)內(nèi)的剪切及駐留時(shí)間，降低擠塑溫度及壓力脈動(dòng)以提高生產(chǎn)率及產(chǎn)品質(zhì)量。外文文獻(xiàn)二Pump's outlineThe pump is the application very widespread general machinery, may say that is place of the fluid flow, nearly has th

23、e pump in the work. Moreover, along with science's and technology's development, pump's application domain is expanding rapidly, according to the over-all state statistics, pump's power consumption approximately composes the national total output of electrical energy 1/5, obviously t

24、he pump is natural consumes energy the wealthy and powerful family. Therefore, raises the pump technical level to save the energy consumption to have the important meaning.First. Centrifugal pump's principle of workThe drive leads impeller revolving through the pump spindle to have the centrifug

25、al force, under the centrifugal action of force, the liquid is flung along the leaf blade flow channel to the impeller export, the liquid sends in after the volute collection the eduction tube. The liquid obtains the energy from the impeller, causes the pressure energy and the speed can increase, an

26、d depends upon this energy the hydraulic transport to the operating location. while the liquid is flung which exports to the impeller, the impeller eye center has formed the low pressure, has had the differential pressure in the imbibition pot and between the impeller center liquid, in the imbibitio

27、n pot's liquid under this differential pressure function, after inhales the pipeline and pump's suction chamber unceasingly enters in the impeller.Second, centrifugal pump's structure and main spare part A centrifugal pump mainly by the pump body, the impeller, the packing ring, the rota

28、tion axis, the axis seals parts and so on box to be composed, some centrifugal pumps are also loaded with the guide pulley, the inducer, the balance disc and so on. 1. Pump body: Namely pump's shell, including suction chamber and delivery chamber. Suction chamber: Its function is enables the liq

29、uid to flow in evenly the impeller.Delivery chamber: Its function collects the liquid, and sends in it the subordinate impeller or guides the eduction tube, at the same time reduces the liquid the speed, causes the kinetic energy to further turn the pressure energy. The delivery chamber has the volu

30、te and the guide vane two forms. 2. Impeller: It is in the centrifugal pump transmits the energy for the liquid only part, the impeller with the bond fixation on the axis, leads revolving along with the axis by the prime mover, passes to through the leaf blade prime mover's energy the liquid.Imp

31、eller classification: According to liquid inflow classification: Single suction impeller (in impeller's one side has an entrance) and double attracts the impeller (liquid from impeller's lateral symmetry liudao impeller passage). Is opposite according to the liquid in centerline's flow d

32、irection classification: Runoff type impeller, axial-flow propeller and interflow type impeller. According to impeller's structural style classification: Shrouded impeller, open type impeller and semi-opened impeller.3. Axis: Is transmits the mechanical energy the important components, the prime

33、 mover's torque passes to the impeller through it. The pump spindle is the pump rotor's major parts, on the axis is loaded with components and so on impeller, axle sleeve, balance disc. The pump spindle depending on the both sides bearing supporting, makes the high speed rotation in the pump

34、, thus the pump spindle in a big way wants the bearing capacity, to be wear-resisting, to be anti-corrosive. Pump spindle's material selects the carbon steel or the alloy steel and after the quenching and retempering treatment generally.4. Packing ring: Is installs in the rotation impeller and t

35、he static pump housing (center-section and guide vane's assembly) between packing assembly. It is function is through controls between the two gap method, increases in the pump between the high and low pressure cavity the fluid flow resistance, reduces divulging. 5. Axle sleeve: The axle sleeve

36、is uses for to protect the pump spindle, causes it not to corrode and the attrition. When necessity, the axle sleeve may replace. 6. Axis seals: The pump spindle and around packing box between end cover's installs short for axis to seal, mainly prevents in pump's liquid divulging and the air

37、 enters in the pump, achieves seals and prevents the air admission to cause the pump cavitation goal. the axis seals form: Namely has skeleton's rubber seal, the packing seal and the mechanical seal.7. axial force balancing unit.Third. Centrifugal pump's prime task parameter 1. Current capac

38、ity: Namely the pump in unit of time discharges the liquid quantity, usually indicated with the Unit of volume that mark Q, the unit has m3/h, m3/s, l/s and so on, 2. Lifting: The transportation unit weight's liquid (pump suction flange) (pump discharge flange) from the pump inlet place to the p

39、ump exit, its energy's increment, indicated with H, the unit is m. 3. Rotational speed: Pump's rotational speed is the pump each minute revolving number of times, expressed with N. Electrical machinery rotational speed N generally about 2900 n/min. 4. Net positive suction head: Centrifugal p

40、ump's net positive suction head is expressed that pump's performance's main parameter,uses the symbolic representation. 5. Power and efficiency: Pump's power input is shaft power P, is also electric motor's output. Pump's output is the active power.Fourth, pump proper energy

41、loss Pump mechanical energy which obtains from the prime mover, has a part to transform into the liquid energy, but another part because in the pump consumes loses. In the pump all losses may divide into the following several items: 1. Hydraulic loss by the liquid in pump impact, the turbulent flow

42、and the surface friction creates. The impact and the eddy current loss are because the liquid flow change direction produces. The liquid flows through the flow channel general meeting which contacts to present the surface friction, from this produces the energy loss is mainly decided by flow channel

43、's length, the size, the shape, the surface roughness, as well as liquid speed of flow and characteristic.2. Volumetric loss: volumetric loss was already obtained the energy liquid to have a part to flee the result which in the pump the class and leaked outward. Pump's volumetric efficiency

44、is 0.930.98 generally. Improves the packing ring and the seal structure, may reduce the leakage, raises the volumetric efficiency. 3. Mechanical loss mechanical loss refers to the impeller lap side and the pump housing friction loss between the liquid, namely the disc loses, as well as pump spindle

45、when packing, bearing and balancing unit and so on mechanical part movement friction loss, generally before primarily.Fifth, pump's speed change-Proportionality law 1. Centrifugal pump's speed change: A centrifugal pump, when its rotational speed change, its rated flow, lifting and the shaft

46、 power will have the change according to the certain proportion relations. At present, uses the frequency conversion velocity modulation electrical machinery to realize centrifugal pump's speed change, is a new important energy conservation way. 2. proportionality law expression In the formula,

47、Q, H, N- pump's rated flow, lifting and shaft power The subscript 1,2 express the different rotational speed separately n- rotational speedSixth, centrifugal pump's ratio rotation Compared to the rotation is the comprehensive parameter which derives by the law of similarity, it is the operat

48、ing mode function, to a pump, the different operating mode has differently compared to the rotation, for ease of carries on the comparison to the different type pump's performance and the structure, the application optimum condition (the peak efficiency spot) the ratio rotation represents this p

49、ump. When chooses the pump, may according to job requirement Q, H and unifies electrical machinery's rotational speed, calculates the ns number, determines pump's type approximately. At that time, used the positive displacement pump generally, at that time, used the centrifugal pump, the int

50、erflow pump, the axial flow pump and so on.Seventh,centrifugal pump's cavitation andinspirationcharacteristic 1.Cavitation phenomenons The pumping station transportation medium's liquid condition and the gas are can transform mutually, the transformed condition is the pressure and the temper

51、ature. Under certain temperature, the liquid starts the critical pressure which vaporizes for the vaporization pressure. The temperature is higher, the liquid vaporization pressure is higher. Pump when revolution, if its overflow part local region (for example impeller blade import later somewhere),

52、 the liquid absolute pressure drops when pulled out delivers the liquid at that time under the temperature vaporization pressure, the liquid then in this place starts to vaporize, the bubble formation (air bubble internal pressure approximately was equal to vaporization pressure). When these air bub

53、bles along with liquid flow forward motion to high pressure region, down to around the air bubble high-pressured liquid causes the air bubble to reduce suddenly congeals. While air bubble vanishing, the liquid particle by the high speed packing hole, occurs hits mutually forms the intense pressure s

54、urge, causes the overflow part to receive the corrosion and the destruction. The above process is called the cavitation. 2. Cavitation will cause serious results: (1). has the vibration and the noise. (2). is influential to pump's operating performance: When the cavitation develops the certain e

55、xtent, the steam bubble produces massively, will stop up the flow channel, will cause pump's current capacity, lifting, the efficiency and so on obviously to drop. (3). will have the destruction to flow channel's material quality: Is mainly nearby the leaf blade entrance the metal weary disi

56、ntegration.3. centrifugal pump's inspiration characteristic: (1). Pump has the cavitation basic condition is: Under leaf blade entrance lowest liquid flow pressure <= this temperature liquid vaporization pressure .(2). effective net positive suction head: The pump entry (potential head is the

57、 entire flood peak which zero) the liquid has subtracts the value which the vaporization delivery head remains only, with expression. (3). pump essential net positive suction head: Liquid flow from pump inlet to impeller in minimal pressure point of force K place complete energy loss, with expressio

58、n. (4). With and difference and relation: Pump not cavitation The pump starts the cavitation <Pump serious cavitation (5). regarding a pump, to guarantee that its safe operation does not have the cavitation, must the net positive suction head also be supposed to add a security allowance regarding

59、 the pump, therefore, pump's permission net positive suction head is: 4. Enhances the centrifugal pump anti-cavitation performance the method to include: (1). I mprovement machine pump structure, reduces, is machine the pump design question. (2). Enhancement installment effective net positive suction head. Most mainly the most commonly used method uses the irrigation i