中高壓外嚙合齒輪泵畢業(yè)設計外文文獻講解

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1、武漢科技大學本科畢業(yè)設計（外文文獻）題目：中高壓外嚙合齒輪泵設計姓名：專業(yè)：交通運輸學號：200934011指導教師：中高壓外嚙合齒輪泵-外文文獻外文文獻一The concept of gear pump is very simple, that it is two of the mostbasic form of the same size gear in a close co-operation of mutualengagement with the rotating shell, the shells internal similar 8 shape, the two gears mo

2、unted 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 teethalong the shell of the rotary movement, the final two hours from the meshing teeth. Speaking in terms

3、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 squeezedmechanically to row out. Because the liquid is incompressible, so the liquid and the tooth at the same time will not be able

4、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, thevolume of discharge is the same. With the continuous rotation of the

5、 driveshaft, pump fluid is continuously discharged. Pump flow directly tothe 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 and gear lubrication, and the pump b

6、ody is also not possible with no gap, it can not be so that- 1 -中高壓外嚙合齒輪泵-外文文獻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 themajority, will still be able to achieve 93% 98% efficiency.For theviscosity or

7、 density change in the process fluid, the pump willnot beaffected 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, blocked, or limiter on the bac

8、k of the hypertension, the pump will maintain a constant flow, until the device in the weakest parts of the mechanicallimit (usually equipped with a torque limiter).For a pump speed, infact, there are restrictions, which mainly depends on the process fluid, if the transmission is oil, pump can rotat

9、e 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 discharge the flow of accurat

10、e, so the value of PV (pressure velocity) is also a limiting factor, and is a process variable. As a resultof these restrictions, gear pump manufacturers will provide a range of products, that is, different specifications and emission (per week to the emission of volume). These pumps will fit the sp

11、ecific 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- 2 -中高壓外嚙合齒輪泵-外文文獻technology, will be a longer working life. D-type bearing a combination of forced lubrication mechanism, so that the polymer

12、 surface by the bearing, and return to the import side of pump to ensure effectivelubrication 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 shaft with precision bearings to ensure non

13、-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 formation of self-sealing. Can also be used

14、 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 flange and install other equipmentline, which m

15、akes the manufacture of tube flange easier. PEP-II with a gear pump with the pump to match the specifications of the heatingelements for the user matching, which ensures rapid heating and heat control. Heating the body and pump in different ways, the damage to these components is limited to a board,

16、 the pump has nothing to do withthe whole.Gear pump by an independent motor drive, to be effectiveinblockingthe upper reaches ofthe pressure pulsation and flowfluctuations. Gear pump in the outlet of the pressure fluctuation can be- 3 -中高壓外嚙合齒輪泵-外文文獻controlled within 1%. In the extrusion production

17、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.外文文獻一翻譯齒輪泵的概念是很簡單的， 即它的最基本形式就是兩個尺寸相同的齒輪在一個緊密配合的殼體內(nèi)相互嚙合旋轉(zhuǎn)， 這個殼

18、體的內(nèi)部類似“8”字形，兩個齒輪裝在里面，齒輪的外徑及兩側與殼體緊密配合。來自于擠出機的物料在吸入口進入兩個齒輪中間，并充滿這一空間，隨著齒的旋轉(zhuǎn)沿殼體運動， 最后在兩齒嚙合時排出。在術語上講，齒輪泵也叫正排量裝置， 即像一個缸筒內(nèi)的活塞， 當一個齒進入另一個齒的流體空間時， 液體就被機械性地擠排出來。 因為液體是不可壓縮的，所以液體和齒就不能在同一時間占據(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)動軸的不間斷地旋轉(zhuǎn)， 泵也就不間斷地排出流體。 泵的流量直接與泵的轉(zhuǎn)速有關。實際上，在泵內(nèi)有

19、很少量的流體損失，這使泵的運行效率不能達到100，因為這些流體被用來潤滑軸承及齒輪兩側，而泵體也絕不可能無間隙配合，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行，對大多數(shù)擠出物料來說，仍可以達到93 98的效率。對于粘度或密度在工藝中有變化的流體，這種泵不會受到太多影響。如果- 4 -中高壓外嚙合齒輪泵-外文文獻有一個阻尼器， 比如在排出口側放一個濾網(wǎng)或一個限制器， 泵則會推動流體通過它們。如果這個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，直至達到裝置中最弱的部件的機械極限( 通常裝有一個扭矩限制器)

20、 。對于一臺泵的轉(zhuǎn)速，實際上是有限制的，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， 但當流體是一種高粘度的聚合物熔體時，這種限制就會大幅度降低。推動高粘流體進入吸入口一側的兩齒空間是非常重要的，如果這一空間沒有填充滿，則泵就不能排出準確的流量，所以PV值( 壓力流速 ) 也是另外一個限制因素，而且是一個工藝變量。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用工藝相配合， 以使系統(tǒng)能力及價格達到最優(yōu)。PEP II 泵的齒輪與軸共為一體，采用通體淬硬工藝，可獲得更長的工作壽命?！癉”型軸承結合了強制潤滑機

21、理，使聚合物經(jīng)軸承表面，并返回到泵的進口側， 以確保旋轉(zhuǎn)軸的有效潤滑。 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 密封結構與聚四氟唇型密封共同構成水冷密封。 這種密封實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口。 為便于安裝， 制造商設計了一個環(huán)形螺栓安裝面，以使與其它設備的法蘭安裝相配合， 這使得筒形法蘭的制造更容- 5 -中高壓外嚙合齒輪泵-外文文獻易。PEP II齒輪

22、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板子上，與整個泵無關。齒輪泵由一個獨立的電機驅(qū)動， 可有效地阻斷上游的壓力脈動及流量波動。在齒輪泵出口處的壓力脈動可以控制在1以內(nèi)。在擠出生產(chǎn)線上采用一臺齒輪泵，可以提高流量輸出速度， 減少物料在擠出機內(nèi)的剪切及駐留時間，降低擠塑溫度及壓力脈動以提高生產(chǎn)率及產(chǎn)品質(zhì)量。外文文獻二Pumps outlineThe pump is the application very widespread general machinery, may say that is place of

23、 the fluid flow, nearly has the pump in the work. Moreover, along with sciences and technologys development, pumps application domain is expanding rapidly, according to the over-all state statistics, pumps power consumption approximately composes the national total output of electrical energy 1/5, o

24、bviously the 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 pumps principle of workThe drive leads impeller revolving through the pump spindle to have the cent

25、rifugal 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 incre

26、ase, and depends upon this energy the hydraulic transport to the operating location. while the liquid is flung which exports to the impeller,- 6 -中高壓外嚙合齒輪泵-外文文獻the impeller eye center has formed the low pressure, ? has had the differential pressure in the imbibition pot and between the impeller cent

27、er liquid, in the imbibition pots liquid under this differential pressure function, after inhales the pipeline and pumps suction chamber unceasingly enters in the impeller.Second, centrifugal pumps structure and main spare partA centrifugal pump mainly by the pump body, the impeller, the packing rin

28、g, the rotation 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 pumps shell, including suction chamber and delivery chamber.Suction chamber: Its function is enables the

29、 liquid to flow in evenly the impeller. Delivery chamber: Its function collects the liquid, and sends in itthe 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

30、volute 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 movers energy the liquid.Impel

31、ler classification:According to liquid inflow classification: Single suction impeller (in impellers one side has an entrance) and double attracts the impeller (liquid from impellers lateral symmetry liudao impeller passage). Is opposite according to the liquid in centerlines flow direction- 7 -中高壓外嚙

32、合齒輪泵-外文文獻classification: Runoff type impeller, axial-flow propeller and interflow type impeller.According to impellers structural style classification: Shrouded impeller, open type impeller and semi-opened impeller.3. Axis: Is transmits the mechanical energy the important components, the? prime move

33、rs torque passes to the impeller through it. The pump spindle is the pump rotors 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, thus the pump

34、 spindle in a big way wants the bearing capacity, to be wear-resisting, to be anti-corrosive.Pump spindles 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 the static pump housin

35、g (center-section and guide vanes 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 is uses for to protect the

36、pump spindle, causes it not to corrode and the attrition. When necessity, theaxle sleeve may replace.6. Axis seals: The pump spindle and around packing box between end covers installs short for axis to seal, mainly prevents in pumps liquid divulging and the air enters in the pump, achieves seals and

37、 prevents the air admission to cause the pump cavitation goal. the axis seals form: Namely has skeletons rubber seal, the packing seal and the mechanical seal.7. axial force balancing unit.Third. Centrifugal pumps prime task parameter- 8 -中高壓外嚙合齒輪泵-外文文獻1. Current capacity: Namely the pump in unit of

38、 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 weights liquid (pump suction flange) (pump discharge flange) from the pump inlet place to the pump exit, itsenergys increment, indic

39、ated with H, the unit is m.3. Rotational speed: Pumps 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 pumps net positive suction head is expressed that p

40、umps performances main parameter,uses the symbolic representation.5. Power and efficiency: Pumps power input is shaft power P, is also electric motors output. Pumps output is the active power.Fourth, pump proper energy lossPump mechanical energy which obtains from the prime mover, has a part to tran

41、sform 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 and the surface friction creates. The impact and the eddy current loss are because

42、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 channels length, the size, the shape, the surface roughness, as well as liquid speed of fl

43、ow 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. Pumps volumetric efficiency is 0.930.98 generally.- 9 -中高壓外嚙合齒輪泵-外文文獻Improves the packing ring and the seal structure, ma

44、y 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 when packing, bearing and balancing unit and soon mechanical part movement f

45、riction loss, generally before primarily.Fifth, pumps speed change-Proportionality law1. Centrifugal pumps speed change:A centrifugal pump, when its rotational speed change, its rated flow, lifting and the shaft power will have the change according to the certain proportion relations. At present, us

46、es the frequency conversion velocity modulation electrical machinery to realize centrifugal pumps speed change, is a new important energy conservation way.2. proportionality law expressionIn the formula, Q, H, N- pumps rated flow, lifting and shaft power The subscript 1,2 express the different rotat

47、ional speed separatelyn- rotational speedSixth, centrifugal pumps ratio rotationCompared to the rotation is the comprehensive parameter which derives by the law of similarity, it is the operating mode function, to a pump, the different operating mode has differently compared to the rotation, for eas

48、e of carries on the comparison to the different type pumps performance and the structure, the application optimum condition (the peak efficiency spot) the ratio rotation represents this pump.When chooses the pump, may according to job requirement Q, H and unifies electrical machinerys rotational spe

49、ed, calculates the ns number, determines pumps type approximately. At that time, used the positive displacement pump generally, at that time, used the centrifugal pump, the interflow pump, the axial flow pump and so on.- 10 -中高壓外嚙合齒輪泵-外文文獻Seventh,centrifugal pumpscavitation andinspirationcharacteris

50、tic1.Cavitation phenomenonsThe pumping station transportation mediums liquid condition and the gas are can transform mutually, the transformed condition is the pressure and the temperature. Under certain temperature, the liquid starts the critical pressure which vaporizes for the vaporization pressu

51、re. 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), the liquid absolute pressure drops when pulled out delivers the liquid at that time under the temperature vaporizati

52、on 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 bubbles along with liquid flow forward motion to high pressure region, down to around the air bubble high-pressured liqu

53、id 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 surge, causes the overflow part to receive the corrosion and the destruction. The above process is called the cavitati

54、on.2. Cavitation will cause serious results:(1). has the vibration and the noise.(2). is influential to pumps operating performance: When the cavitation develops the certain extent, the ? steam bubble produces massively, will stop up the flow channel, will cause pumps current capacity, lifting, the

55、efficiency and so on obviously to drop.(3). will have the destruction to flow channels material quality: Is mainly nearby the leaf blade entrance the metal weary disintegration.3. centrifugal pumps inspiration characteristic:- 11 -中高壓外嚙合齒輪泵-外文文獻(1). Pump has the cavitation basic condition is: Under

56、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 entire flood peak which zero) the liquid has subtracts the value which the vaporization delivery head remains only, with ex

57、pression.(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 expression.(4). With and difference and relation:Pump not cavitationThe pump starts the cavitationPump serious cavitation(5). regardin

58、g 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 the pump, therefore, pumps permission net positive suction head is:4. Enhances the centrifugal pump anti-cavitation performance theme

59、thod 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 inspiration installment.In addition, reduces the inspiration pipeline

60、 resistance loss as far as possible, reduces the liquid the saturated steam tension, namely when design inspiration pipeline selects caliber big as far as possible, length short, the bend and valve few, transportation liquid temperature as far as- 12 -中高壓外嚙合齒輪泵-外文文獻possible low and so on measures, m

61、ay enhance the installment the effective cavitation remainder.5. axial force balancing unit(1). axial force production reason Around because the impeller the both sides the fluid pressuredistributed situation different (wheel cap lateral pressure is low, ? wheel disk pressure high) causes axial forc

62、e A1, its direction for from impeller back side direction impeller eye.The fluid flows in and flows out dynamical reaction A2 which impellers direction and the speed different produce, its direction and A1 are opposite, therefore line shaft directive force A=A1-A2, the direction is ordinary and A1 same (general A2 is small).(2). Axial force balanced Uses double attracts the type impeller: The impeller lateralsymmetry, the fluid from the both sides inspiration, the axial force automatic counter-balance achieves balanced.Opens the balancing hole or installs the compensating pipe:A: Open