人人文库网 > 图纸下载 > 毕业设计 > 叶轮座零件工艺设计及专用夹具设计【11张CAD图纸+毕业论文】【答辩通过】

单级离心泵设计外文翻译.doc

叶轮座零件工艺设计及专用夹具设计【11张CAD图纸+毕业论文】【答辩通过】

资源目录

叶轮座零件工艺设计及专用夹具设计【全套CAD图纸+毕业论文】【答辩通过】.rar

马磊叶轮座加工工艺过程卡.xls---(点击预览)

叶轮座说明书.doc---(点击预览)

相关资料

计划周记进度检查表.xls---(点击预览)

开题报告.doc---(点击预览)

叶轮座任务书.doc---(点击预览)

单级离心泵设计外文翻译.doc---(点击预览)

A0夹具.dwg

A1定位盘(夹具体）.dwg

A1马磊叶轮座毛坯图.dwg

A1马磊叶轮座零件图.dwg

A2叶轮座夹具底座.dwg

A2叶轮座夹具支承板.dwg

A3叶轮座夹具压板.dwg

A3叶轮座夹具支承管.dwg

A3叶轮座夹具斜楔A.dwg

A3叶轮座夹具斜楔B.dwg

A3定位短销.dwg

压缩包内文档预览：

编号：445871 类型：共享资源大小：1.98MB 格式：RAR 上传时间：2015-07-02 上传人：好资料QQ****51605 IP属地：江苏

45
积分

版权申诉 word格式文档无特别注明外均可编辑修改；预览文档经过压缩，下载后原文更清晰！ 立即下载

关键词：: 叶轮零件工艺设计专用夹具全套 cad 图纸毕业论文答辩通过

资源描述：

摘要

本论文主要研究叶轮座的加工工艺与其专用夹具的设计。根据零件使用要求，分析零件的机械加工工艺性，编制零件机械加工工艺规程，形成全套工艺文件，即工艺过程卡、机加工工艺卡、工序卡；绘制零件图；在制定工艺过程中，要确定各工序的安装工位和该工序需要的工步，加工该工序的机车及机床的进给量，切削深度，主轴转速和切削速度，该工序的夹具，刀具及量具，还有走刀次数和走刀长度，最后计算该工序的基本时间，辅助时间和工作地服务时间。设计叶轮座零件加工的专用夹具，绘制夹具装配图及全套非标零件图，分析夹具的定位精度，切削力、夹紧力。

关键词：加工工艺；专用夹具；全套工艺文件；定位精度

Abstract

This thesis mainly studies the impeller machining process and its special fixture design. According to parts use requirement, manufacturability analysis of machining parts, prepare the parts machining process planning, formed a full range of technology document, namely the process sheet, machining process CARDS, process CARDS; Draw the part drawing; In the process of making process, to determine the installation location of each process step and the work of the process need, locomotives and machine tools in processing the process feed, cutting depth, spindle speed and cutting speed, the process of fixture, cutting tools and measuring tool, and feeding frequency and feeding length, finally calculated the process of basic time, auxiliary time and service time is carried out. Special fixture design of impeller parts processing, fixture assembly drawings and a full range of non-standard parts charting, analysis of fixture locating precision, cutting force, clamping force.

Key words: process; Special fixture; Full set of process documents; Positioning accuracy

摘要III

AbstractIV

目录V

1 绪论1

1.1 本课题的研究内容和意义1

1.2 国内外的发展概况1

1.3本课题应达到的要求1

2 零件分析2

2.1 零件作用与分析2

2.2零件的生产纲领与生产类型2

2.3零件的工艺分析2

2.3.1 主要加工面：3

2.3.2主要基准面3

3叶轮座加工的主要问题和工艺过程设计所采取的相应措施4

3.1 确定毛坯的制造形式4

3.2基面的选择4

3.2.1粗基准的选择4

3.2.2精基准的选择4

3.3确定加工工艺路线4

3.4 机械加工余量、工序尺寸及毛坯尺寸的确定6

3.5 确定切削用量9

4专用夹具设计25

4.1零件的加工工艺分析25

4.2定位基准的选择25

4.3定位夹紧方案的确定25

4.4切削力的计算26

4.5定位元件的设计27

4.6定位误差计算27

4.6.1 工件孔与定位心轴的定位误差分析27

4.6.2 一面两销定位误差分析28

4.7夹紧元件的设计30

4.7.1夹紧力的计算30

4.7.2 自锁条件30

4.7.3 斜楔增力特性与升角关系31

4.7.4 斜楔夹紧机构的类型与计算31

5 结论与展望33

5.1 结论33

5.2 不足之处与未来展望33

致谢34

参考文献35

1 绪论

1.1 本课题的研究内容和意义

本论文研究的是叶轮座零件加工工艺及专用夹具设计。根据零件使用要求，分析零件的机械加工工艺性，编制零件机械加工工艺规程，形成全套工艺文件，即工艺过程卡、机加工工艺卡、工序卡；绘制零件图；在制定工艺过程中，要确定各工序的安装工位和该工序需要的工步，加工该工序的机车及机床的进给量，切削深度，主轴转速和切削速度，该工序的夹具，刀具及量具，还有走刀次数和走刀长度，最后计算该工序的基本时间，辅助时间和工作地服务时间。设计叶轮座零件加工的专用夹具，绘制夹具装配图及全套非标零件图，分析夹具的定位精度，切削力、夹紧力。

叶轮座是泵体的主要零部件之一，其加工精度，不但影响到泵的性能，而且影响到整机运行的平稳性。在普通卧式镗床的工作台上，安装一通用的分度盘，通过中间的通孔定位，用螺栓、压板和螺栓螺母将工件压紧，虽然这种加工方法可以满足设计要求，但由于镗床的对刀不方便，精度不易控制，因此加工效率低，加工成本高。而且利用镗床加工这样小的零件，机床的功能得不到充分发挥，不够经济。所以我们设计了专用工装，便能轻易地在普通车床上完成叶轮座上的孔加工。

全部文件.gif

A1马磊叶轮座零件图.gif

A1马磊叶轮座毛坯图.gif

A0夹具.gif

A1定位盘(夹具体）.gif

A2叶轮座夹具底座.gif

A2叶轮座夹具支承板.gif

内容简介：: 1 CENTRIFUGAL PUMPS IN THE CHEMICAL INDUSTRY Abstract : A centrifugal pump converts the input power to kinetic energy in the liquid by accelerating the liquid by a revolving device - an impeller. The most common type is the volute pump. Fluid enters the pump through the eye of the impeller which rotates at high speed. The fluid is accelerated radially outward from the pump chasing. A vacuum is created at the impellers eye that continuously draws more fluid into the pump . This article stresses on a series of centrifugal pumps， From a brief introduction to the principles. Keywords : centrifugal pump ,Introduction ,Working principle , Cavitation ， Mechanism of Cavitation ， Solution and Remedies 1. Introduction Pump ,device used to raise ,transfer ,or compress liquids and gases .Four general classes of pumps for liquids are described below .In all of them ,steps are taken to prevent cavitation (the formation of a vacuum) ,which would reduce the flow and damage the structure of the pump .Pumps used for gases and vapors are usually known as compressors .The study of fluids in motion is called fluid dynamics. Water pump ,device for moving water from one location to another ,using tubes or other machinery .Water pumps operate under pressures ranging from a fraction of a pound to more than 10,000 pounds per square inch .Everyday examples of water pumps range from small electric pumps that circulate and aerate water in aquariums and fountains to sump pumps that remove water from beneath the foundations of homes . One type of modern pumps used to move water is the centrifugal pump .Early version of the centrifugal pump ,the screw pump ,consists of a corkscrew-shaped mechanism in a pipe that ,when rotated ,pulls water upward .Screw pumps are often used in waste-water treatment plants because they can move large amounts of water without becoming clogged with debris .In the ancient Middle East the need for irrigation of farmland was a strong inducement to develop a water pump .Early pumps in this region were simple devices for lifting buckets of water from a source to a container or a trench .Greek mathematician and inventor Archimedes is thought to have devised the first screw pump in the third century BC .Later Greek inventor Ctesibius develop the first lift pump .During the late 17th and early 18th Centuries AD ,British engineer Thomas Savery ,French physicist Denis Papin ,And British blacksmith and inventor Thomas Newcomen contributed to the development of a water pump that used steam to power the pump piston .The steam-powered water pumps first wide use was in pumping water out of mines .Modern-day examples of centrifugal pumps are those used at the Grand Coulee Dam on the Columbia River .This pump system has the potential to irrigate over one million acres of land . Also known as rotary pumps ,centrifugal pumps have a rotating impeller ,also known as a blade ,that is immersed in the liquid .Liquid enters the pump near the axis of the impeller ,and the rotating impeller sweeps the liquid out toward the ends of the impeller blades at high pressure .The impeller also gives the liquid a relatively high velocity that can be converted into pressure in a stationary part of the pump ,known as the diffuser .In high-pressure pumps ,a number of impeller may be used in series ,and the diffusers following each impeller may contain guide vanes to gradually reduce the liquid velocity .For lower-pressure pumps ,the diffuser is generally a spiral passage ,known as a volute ,with its cross-sectional area increasing gradually to reduce the velocity efficiently .The impeller must be primed before it can begin operation ,that is ,the impeller must be surrounded by liquid when the pump is started .This can be done by placing a check valve in the suction line ,which holds the liquid in the pump when the impeller is not rotating .If this valve leaks ,the pump may need to be primed by the introduction of liquid from an outside source such as the discharge reservoir .A centrifugal pump generally has a valve in the discharge line to control the flow and nts 2 pressure .For low flows and high pressures ,the action of the impeller is largely radial .For higher flows and lower discharge pressure ,the direction of the flow within the pump is more nearly parallel to the axis of the shaft ,and the pump is said to have an axial flow .The impeller in this case acts as a propeller .The transition from one set of floe conditions to the other is gradual ,and for intermediate condition , the device is called a mixed-flow pump . 2.The Centrifugal Pump The centrifugal pump is by far the most widely used type in the chemical and petroleum industries .It will pump liquids with very wide ranging properties and suspensions with a high solids content including ,for example ,cement slurries ,and may be constructed from a very wide rang of corrosion resistant materials .The whole pump casing may be constructed from plastic such as polypropylene or it may be fitted with a corrosion-resistant lining .Because it operates at high speed ,it may be directly coupled to an electric motor and it will give a high flow rate for its size . In this type of pump ,the fluid is fed to the centre of a rotating impeller and is thrown outward by centrifugal action .As a result of the high speed of rotation the liquid acquires a high kinetic energy and the pressure difference between the suction and delivery sides arises from the conversion of kinetic energy into pressure energy . The impeller consists of a series of curved vanes so shaped that the flow within the pump is as smooth as possible .The greater the number of vanes on the impeller ,the greater is the control over the direction of the liquid and hence the smaller are the losses due to turbulence and circulation between the vanes .In the open impeller ,the vanes are fixed to a central hub ,whereas in the closed type the vanes are held between two supporting plates and leakage across the impeller is reduced .As will be seen later ,the angle of the tips of the blades very largely determines the operating characteristics of the pump . The liquid enters the casing of the pump， normally in an axial direction， and is picked up by the vanes of the impeller In the simple type of centrifugal pump， the liquid discharges into a volute， a chamber of gradually increasing crosssection with a tangential outlet A volute type of pump is shown in Fig.(a) In the turbine pump-Fig (b)the liquid flows from the moving vanes of the impeller through a series of fixed vanes forming a diffusion ring This gives a more gradual change in direction to the fluid and more efficient conversion of kinetic energy into pressure energy than is obtained with the volute type The angle of the leading edge of the fixed vanes should be such that the fluid is received without shock The liquids flows along the surface of the impeller vane with a certain velocity whilst the tip of the vane is moving relative to the casing of the pump The direction of motion of the liquid relative to the pump casing-and the required angle of the fixed vanesis found by compounding these two velocities In Fig c， nts 3 c. vu is the velocity of the liquid relative to the vane and tu is the tangential velocity of the tip of the vane；compounding these two velocities gives the resultant velocity 2u of the liquid It is apparent， therefore，that the required vane angle in the diffuser is dependent on the throughput， the speed of rotation， and the angle of the impeller blades The pump will therefore operate at maximum efficiency only over a narrow range of conditions Virtual head of a centrifugal pump The maximum pressure is developed when the whole of the excess kinetic energy of the fluid is converted into pressure energy. As indicated below the head is proportional to the square of the radius and to the speed， and is of the order of 60m for a singlestage centrifugal pump； for higher pressures，multistage pumps must be used Consider the liquid which is rotating at a distance of between r and r+dr from the centre of the pump(Fig d) d The mass of this element of fluid dm is given by 2rdrd， where is the density of the fluid and 6 is the width of the element of fluid。 If the fluid is traveling with a velocity u and at an angle to the tangential direction The angular momentum of this mass of fluid = dM (urcos) The torque acting on the fluid d is equal to the rate of change of angular momentum with time， as it goes through the pump D = dM /t(urcos)=2rbdr/t(urcos) (2.1) The volumetric rate of flow of liquid through the pump： Q=2rb/t (2.2) nts 4 Dr =Q d(urcos) (2.3) The total torque acting on the liquid in the pump is therefore obtained integrating d between the limits denoted by suffix 1 and suffix 2， where suffix 1 refers to the conditions at the inlet to the pump and suffix 2 refers to the condition at the discharge Thus， =Q ( 2u 2r cos 2 - 1u 1r cos 1 ) The advantages and disadvantages of the centrifugal pump The main advantages are： (1) It is simple in construction and can， therefore， be made in a wide range of materials (2)There is a complete absence of valves (3)It operates at high speed(up to 100 Hz)and， therefore， can be coupled directly to an electric motor. In general， the higher the speed the smaller the pump and motor for a give n duty (4)It gives a steady delivery (5)Maintenance costs are lower than for any other type of pump (6)No damage is done to the pump if the delivery line becomes blocked， provided it is not run in this condition for a prolonged period (7)It is much smaller than other pumps of equal capacity It can， therefore， be made into a sealed unit with the driving motor and immersed in the suction tank (8)Liquids containing high proportions of suspended solids are readily handled The main disadvantages are： (1)The singlestage pump will not develop a high pressure Multistage pumps will develop greater heads bat they are very much more expensive and cannot readily be made in corrosionresistant material because of their greater complexity It is generally better to use very high speeds in order to reduce the number of stages required (2)It operates at a high efficiency over only a limited range of conditions; this applies especially to turbine pumps (3)It is not usually self-priming. (4)If a non-return valve is not incorporated in the delivery or suction line, the liquid will run back into the suction tank as soon as the pump stops (5)Very viscous liquids cannot he handled efficiently 3. Cavitation in centrifugal pump （ 1） The term cavitation comes from the Latin word cavus, which means a hollow space or a cavity. Websters Dictionary defines the word cavitation as the rapid formation and collapse of cavities in a flowing liquid in regions of very low pressure. In any discussion on centrifugal pumps various terms like vapor pockets, gas pockets, holes, bubbles, etc. are used in place of the term cavities. These are one and the same thing and need not be confused. The term bubble shall be used hereafter in the discussion. In the context of centrifugal pumps, the term cavitation implies a dynamic process of formation of bubbles inside the liquid, their growth and subsequent collapse as the liquid flows through the pump. Generally, the bubbles that form inside the liquid are of two types: Vapor bubbles or Gas bubbles. 1.Vapor bubbles are formed due to the vaporisation of a process liquid that is being pumped. The cavitation condition induced by formation and collapse of vapor bubbles is commonly referred to as Vaporous Cavitation. 2.Gas bubbles are formed due to the presence of dissolved gases in the liquid that is being pumped nts 5 (generally air but may be any gas in the system). The cavitation condition induced by the formation and collapse of gas bubbles is commonly referred to as Gaseous Cavitation. （ 2） Important Definitions: To enable a clear understanding of mechanism of cavitation, definitions of following important terms are explored. Static pressure, Dynamic pressure, Total pressure, Static pressure head, Velocity head, Vapour pressure. Static pressure ： The static pressure in a fluid stream is the normal force per unit area on a solid boundary moving with the fluid. It describes the difference between the pressure inside and outside a system, disregarding any motion in the system. For instance, when referring to an air duct, static pressure is the difference between the pressure inside the duct and outside the duct, disregarding any airflow inside the duct. In energy terms, the static pressure is a measure of the potential energy of the fluid. Dynamic pressure： A moving fluid stream exerts a pressure higher than the static pressure due to the kinetic energy ( mv2) of the fluid. This additional pressure is defined as the dynamic pressure. The dynamic pressure can be measured by converting the kinetic energy of the fluid stream into the potential energy. In other words, it is pressure that would exist in a fluid stream that has been decelerated from its velocity v to zero velocity. Total pressure： The sum of static pressure and dynamic pressure is defined as the total pressure. It is a measure of total energy of the moving fluid stream. i.e. both potential and kinetic energy. Velocity head： Vapor pressure is the pressure required to keep a liquid in a liquid state. If the pressure applied to the surface of the liquid is not enough to keep the molecules pretty close together, the molecules will be free to separate and roam around as a gas or vapor. The vapor pressure is dependent upon the temperature of the liquid. Higher the temperature, higher will be the vapor pressure. （ 3） Cavitation Damage： Cavitation can destroy pumps and valves, and cavitation causes a loss of efficiency in pumps immediately, and also a continuously increasing loss of efficiency as the equipment degrades due to erosion of the pump components by cavitation. Therefore It is important to understand the phenomena sufficiently to predict and therefore reduce cavitation and damage from cavitation, and also to diagnose and find practical solutions to cavitation problems。 1） Cavitation Enhanced Chemical Erosion Pumps operating under cavitation conditions become more vulnerable to corrosion and chemical attack. Metals commonly develop an oxide layer or passivated layer which protects the metal from further corrosion. Cavitation can remove this oxide or passive layer on a continuous basis and expose unprotected metal to further oxidation. The two processes (cavitation & oxidation) then work together to rapidly remove metal from the pump casing and impeller. Stainless steels are not invulnerable to this process. 2） Materials Selection There is no metal, plastic, or any other material known to man, that can withstand the high levels of energy released by cavitation in the forms of heat and Phenomenon of Cavitation nts 6 pressure. In practice however, materials can be selected that result in longer life and customer value in their ability to withstand cavitation energies, so that attention to pump construction materials is valuable and productive. Where cavitation is not a problem or not predicted to be a problem, common materials such as cast iron and bronze are suitable for pump construction. There are millions of cast iron and bronze pumps that work fine for 20 years or more without any problem even though many of those pumps experience some cavitation. （ 4） Mechanism of Cavitation： The phenomenon of cavitation is a stepwise process as shown in Figure (below). Step One, Formation of bubbles inside the liquid being pumped. The bubbles form inside the liquid when it vaporises i.e. phase change from liquid to vapor. But how does vaporization of the liquid occur during a pumping operation? Vaporization of any liquid inside a closed container can occur if either pressure on the liquid surface decreases such that it becomes equal to or less than the liquid vapor pressure at the operating temperature, or the temperature of the liquid rises, raising the vapor pressure such that it becomes equal to or greater than the operating pressure at the liquid surface. For example, if water at room temperature (about 77 F) is kept in a closed container and the system pressure is reduced to its vapor pressure (about 0.52 psia), the water quickly changes to a vapor. Also, if the operating pressure is to remain constant at about 0.52 psia and the temperature is allowed to rise above 77 F, then the water quickly changes to a vapor. Just like in a closed container, vaporization of the liquid can occur in centrifugal pumps when the local static pressure reduces below that of the vapor pressure of the liquid at the pumping temperature. Step Two, Growth of bubbles Unless there is no change in the operating conditions, new bubbles continue to form and old bubbles grow in size. The bubbles then get carried in the liquid as it flows from the impeller eye to the impeller exit tip along the vane trailing edge. Due to impeller rotating action, the bubbles attain very high velocity and eventually reach the regions of high pressure within the impeller where they start collapsing. The life cycle of a bubble has been estimated to be in the order of 0.003 seconds。 Step Three, Collapse of bubbles， As the vapor bubbles move along the impeller vanes, the pressure around the bubbles begins to increase until a point is reached where the pressure on the outside of the bubble is greater than the pressure inside the bubble. The bubble collapses. The process is not an explosion but rather an implosion (inward bursting). Hundreds of bubbles collapse at approximately the same point on each impeller v

温馨提示:
1: 本站所有资源如无特殊说明，都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等，如果需要附件，请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸，网页内容里面会有图纸预览，若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对用户上传分享的文档内容本身不做任何修改或编辑，并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容，请与我们联系，我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

人人文库网所有资源均是用户自行上传分享，仅供网友学习交流，未经上传用户书面授权，请勿作他用。