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关键词：: 半轴壳体左右加工组合机床总体设计课程毕业设计半轴壳体左右两面孔加工组合机床总体设计

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题目半轴壳体左右两面孔加工组合机床的总体设计

主要研究目标或研究内容)1.组合机床方案的拟定；

2.选择刀具、确定相应的切削用量；

3.绘制被加工零件工序图、加工示意图、机床联系尺寸图；

4.编制机床生产率计算卡

课题要求、主要任务及数量（指图纸规格、张数，说明书页数、论文字数等）独立完成不少于3张A0图纸的结构设计图、装配图和零件图，其中应包含1张以上用计算机绘制的具有中等难度的A1号图纸，同时至少有折合A1图幅以上的图纸用三维绘制，查阅15篇以上与题目相关的文献。并需翻译一万印刷符（或译出3000汉字）以上的有关技术资料（并附原文）。毕业论文的字数一般为1..5万字（约40~50页）。

进度计划第1～3周：借阅相关资料、了解相关知识，毕业实习，完成开题报告

第4～6周：熟悉加工零件、了解用途、绘制零件图

第7～13周：确定设计方案、分析、计算、绘图

第14～15周：编写说明书、定稿、打印、答辩前准备阶段

主要参

考文献[1] 沈阳工业大学大连铁道学院吉林工学院编.组合机床设计.上海:上海科学技术出版社,1985.

[2] 周诵明. 机械类专业毕业设计指导书. 武汉：华中理工大学出社，1993.

[3] 赵雪松,任小中, 于华. 机械制造装备设计.武汉:华中科技大学出版社， 2009.

[4] 谢家瀛. 组合机床设计简明手册.北京：机械工业出版社，2002.

半轴壳体左右两面孔加工组合机床总体设计

摘要

半轴壳体左右两面钻孔组合机床总体设计是根据加工零件，拟定工艺和结构方案，选择合适的刀具，拟定合适的结构方案和工艺，定出通用部件，并进行绘图和相关方案和技术文件的设计。

满足加工内容如下：对左右端面经行钻孔加工，左端面上孔径为23.4mm和17.4mm的孔各两个，右端面上是孔径为13mm的六个孔。组合机床总体设计和普通机床的设计过程是相似的，组合机床使用多刀同时加工的，因此自动化程度高，因而比普通机床生产效率高，产品质量高，所需劳动力少。组合机床的总体设计是通过对零件分析等，用三图一卡表达出总体方案，包括绘制零件加工的工序图、加工示意图、联系尺寸图，及生产率计算卡。设计组合机床满足生产要求，符合实际情况，并且节约材料，满足市场需求，经济实惠。

关键词：半轴壳体，组合机床，总体设计

HALF SHAFT CASING AROUND TWO FACE PROCESSING AND THE OVERALL DESIGN OF COMBINED MACHINE TOOL

ABSTRACT

Overall design about half shaft shell sides drill combination machine tools is according to the machining parts, drafting process and the structure scheme, choosing the right tool, to formulate appropriate structure scheme and process, set general components, and for the design of drawing and relevant scheme and technical documents.

About satisfy processing content is as follows: to end the row drilling processing, on the left end face diameter of 23.4 mm and 17.4 mm hole of the two, on the right end is size for six of the 13 mm hole. Overall design of combined machine tool and the design process of ordinary machine tool is similar, combination machine tools using multiple blade processing at the same time, so a high degree of automation, and thus is higher than common machine tool production efficiency, product quality is high, you need less labor. The overall design of the modular machine tool is based on the component analysis and so on, with three figure one card expresses the overall scheme, including map parts processing process, processing sketch, contact size chart, and productivity calculation card. Design combination machine tools to meet production requirements, in line with the actual situation, and save material, meet market demand, economical and practical.

KEY WORDS: Half shaft casing, Combination machine tools, general design

目　录

前　言1

第1章组合机床总体设计步骤3

1.1制定方案3

1.1.1确定工艺方案3

1.1.2机床的配置型式及结构方案3

1.1.3总体设体—三图一卡4

第2章制定组合机床方案5

2.1影响组合机床方案制定的那些因素5

2.1.1被加工零件的加工精度和加工工序5

2.1.2被加工零件的特点5

2.1.3零件的生产批量6

2.1.4机床应用条件6

2.2制定工艺方案7

2.2.1工艺方法达到的制造要求7

2.2.2工艺原则的确定7

2.2.3定位基准及夹紧点的确定8

2.3确定机床配置型式及结构方案9

2.3.1机床各项注意内容9

第3章刀具部分10

3.1关于切削用量的内容10

3.1.1切削用量选择特点及注意问题10

3.1.2切削用量选择方法12

3.2切削力、扭矩、功率及刀具耐用度计算13

3.2.1各计算内容13

3.3刀具结构15

3.3.1选择刀具注意内容15

第4章图纸内容及要求16

4.1被加工零件16

4.1.工序图作用及内容16

4.1.2工序图注意事项17

4.2加工示意图17

4.2.1示意图作用及内容17

4.2.2示意图的画法及注意事项17

4.2.3相关部件确定18

4.2.4动力部件工作循环及工作行程22

4.3联系尺寸图作用及内容22

4.3.1联系尺寸图22

4.3.2选择动力部件23

4.3.3需考虑的问题25

4.3.4联系尺寸的画法和过程27

第5章组合机床生产率计算28

结　论30

谢辞31

参考文献32

前　言

机床在现代机械制造业中占有最重要的地位。通常在机械制造厂中，机床所担负生产总量，大约是机械制造业的90%，机床结构和工艺是对机械加工产品的质量及经济性影响的重要因素，它是衡量国家制造水平重要依据。另外，通过这么多年来机床的不断的发展，一次次的更新，出现了现在这么多、结构优良和性能较好的机床，才使现代制造业出现了翻天覆地的变化，组合机床的发展，节约了大量人力，释放了劳动力，提高了生产力，在现代机械领域，组合机床的设计非常重要的意义。

半轴壳体左右两两面钻孔组合机床总体设计，主要同过对加工工艺的要求，选择合适刀具，根据切削用量算出切削力，一步步选择主轴，进而确定工进长度，选择通用部件，绘制出三图一卡，来完成总体部分的相关设计。以达到的技术要求目的，即满足加工精度，耐用度，生产效率及节约资源。在设计中主要面对工艺分析，刀具选择，通用部件合理性等问题。通过认真分析计算一步步完成设计。

半轴壳体左右两面钻孔组合机床设计主要是让我们全面合理的分析理解，最终加工精度要求及达到生产率要求。同过理论计算，让理论和标准相结合，然后选择合适的通用部件。

全球第一台组合机床在1908年被设计出来，在这30年后组合机床在全球各国得到快速发展。时至今日，组合机床成为现代机械制造业的必不少设备。现代机械制造业全方位对组合机床提出了更高的要求，它也在连绵不绝的接受新技术，不断更新发展。

我国也不甘于落后，我国面对国际机床的发展，我国也不断发展，产生了生产和销售都不错的势头，到2005年，我国组合机床产量已达10000多台，产值达3.9亿，我国加入WTO以后，机械制造业我国所面临前所未有的挑战，组合机床不断发展。随着我国的发展，组合机床不断发展，使产品销售不断增长。关于组合机床的各项经济指标均有所增长。新机床不断出现，新技术的不断运用，促使我国组合机床不断发展。

参考文献

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工序图.gif

加工示意图.gif

联系尺寸图.gif

零件1.gif

内容简介：: 226 2012,24(2):226-234 DOI: 10.1016/S1001-6058(11)60238-2 RESEARCH OF INNER FLOW IN A DOUBLE BLADES PUMP BASED ON OPENFOAM* LIU Hou-lin, REN Yun, WANG Kai, WU Deng-hao, RU Wei-min,TAN Ming-gao Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhengjiang 212013, China, E-mail: liuhoulin (Received September 24, 2011, Revised January 9, 2012) Abstract: The inner flow analysis of centrifugal pumps has gradually become an important issue for the hydraulic design and performance improvement. Nowadays, CFD simulation toolbox of pump inner flow mainly contains commercial tools and open source tools. There are some defects for commercial CFD software for the numerical simulation of 3-D turbulent internal flow in pump, especially in capturing the flow characteristics under the off-design operating conditions. Additionally, it is difficult for researchers to do further investigation because of the undeclared source. Therefore, an open source software like Open Field Operation and Manipulation (OpenFOAM) is increasingly popular with researchers from all over the world. In this paper, a new computational study was implemented based on the original solver and was used to directly simulate the steady-state inner flow in a double blades pump, with the specific speed is 111. In order to disclose the characteristics deeply, three research schemes were conducted. The ratios ( /dQQ) of the flow rate are 0.8, 1.0 and 1.2, respectively. The simulation results were verified with the Particle Imaging Velocimetry (PIV) experimental results, and the numerical calculation results agree well with the experimental data. Meanwhile, the phenomena of flow separation under the off-design operating conditions are well captured by OpenFOAM. The results indicate that OpenFOAM possesses obvious strong predominance in computing the internal flow field of pump. The analysis results can also be used as the basis for the further research and the improvement of centrifugal pump. Key words: numerical simulation, double blades pump, internal flow, Particle Imaging Velocimetry (PIV) IntroductionDouble blades pumps is a kind of centrifugal pump with two blades. There are two symmetrical curve impeller passages from its inlet to outlet and the impeller outlet is quite wide. Therefore, it usually becomes one of impeller shapes in solid-liquid two- phase centrifugal pump. However, due to the short development history and the imperfect design theory, its impellers are often designed with a combination of experience of the designers so far in practice, so that its performance and stability are not ensured1-3. Determining the pump performance is decided by * Project supported by the National Natural Science Funds for Distinguished Young Scholar (Grant No. 50825902), the National Natural Science Foundation of China (Grant Nos. 51079062, 51179075 and 51109095) and the Natural Science Foundation of Jiangsu Province (Grant Nos. BK2009006, BK2010346). Biography: LIU Hou-lin (1971-), Male, Ph. D., Professor examining its inner flow characteristics is undoubte- dly the best method to improve the performance of pumps4-6. Recently, with the rapid progress in CFD and computer technology, the internal flow simulation has gradually become the important foundation of optimization and design for turbo-machinery7-10. Now, the fluid machinery CFD simulation toolbox mainly contains commercial tools and open source tools. Over the years, the commercial software pack- ages are fashionable in the world by its abundant fun- ction and fine easy-use quality. On the other hand, as a CFD software, commercial tool is not very profe- ssional, the computational results for pumps are less than satisfactory, especially in capturing the flow cha- racteristics under the off-design operating conditions. Furthermore, its undeclared source brings a considera- ble inconvenience for the application of numerical simulation in fluid machineries. Although codes can be added to implementation through user-define-fun- ctions, it has a strong limitation. For example, when the SIMPLE algorithm and two-equation turbulence nts 227models have to be improved, one need to have a through understanding of the governing equations, discretization method, turbulence models and iteration algorithm. However, the core algorithm code and data processing method can not be acquired because of commercialization and only several options can be chosen. Therefore, many open source CFD software are becoming popular and a high quality open source CFD simulation platform like the Open Field Operation and Manipulation (OpenFOAM) is out- standing due to its powerful function, clear archite- cture, expand feature and unified format. The OpenFOAM CFD toolbox was released as an open source December 10, 2004, which is based on C+ routine and contains many C+ modules which can be freely combined with some other modules such as tensor, vector, turbulence models, numerical algori- thm, discretion modules, automatic control modules and so on. Therefore, it is convenient to employ its solvers in simulating complex physical models in che- mical reaction, turbulent flow and heat conduction, etc. A variety of work on the internal flow in fluid machinery via OpenFOAM was done. Nilsson11con- ducted the steady and unsteady computation of the flow in the Hllerforsen turbine runner and draft tube, and compared the results obtained by the OpenFOAM with those by the CFX-5 and in experiments. Eve- ntually, the applicability and reliability of the OpenFOAM in a Kaplan water turbine runner and draft tube was verified. Petit et al.12validated an im- plementation of the General Grid Interface (GGI) in the OpenFOAM by using the frozen rotor steady app- roach and the sliding grid unsteady approach. How- ever, all the simulations were performed for a simpli- fied 2-D model of a centrifugal pump. Li13simulated boundary layer in wind tunnel by OpenFOAM, which revealed that it was suitable for using OpenFOAM to conduct a Computational Wind Engineering (CWE) research. Currently, there is not much work regarding the study of the inner flow of pumps through compa- rison between the OpenFOAM simulation and experi- ments, and the related reports are seldom found. As an open source code, the OpenFOAM provi- des direct access to models and solver implementation details. However, there are some defects for the OpenFOAM in the numerical simulation of 3-D turbu- lent internal flow in hydroturbines. For the CFD simu- lation of hydroturbines, separate 3-D mesh passages or full geometry are generally connected together in order to simulate the flow of water through a succe- ssion of complex geometries like pumps where the stationary suction and volute are located, along with the rotating impeller. The requirement to fit all the meshes with conformal matching interfaces is often very difficult or leads to geometric compromises that would affect the numerical quality of the simulation results. Therefore, there is a need for a treatment of rotor-stator interfaces, which is necessary for the simulation of the whole hydroturbines inner flow. Although the capability has existed in the OpenFOAM, there is no definition in the case directory. There is also a need for a set of boundary conditions that makes it easy to capture basic features in a similar way as it can be done in some other CFD solvers. Furthermore, relaxation factors which control under- relaxation, have an important influence on improving stability of a computation. However, there is no gui- ding principle about those factors. Therefore, the paper focuses on centrifugal pump with the conside- ration of these factors. The numerical simulation of pump by using the OpenFOAM is achieved and the computational results are verified by Particle Imaging Velocimetry (PIV) experiments. The research also provides the foundation for achieving higher computa- tion accuracy of pump inner flow by improving the CFD method with self-compiling program in the OpenFOAM. In this paper, in order to compute the intera- ctions between rotating and fixed components in pumps, a Multiple Reference Frames (MRF) solver is used. At the same time, the simulation results are also validated by PIV test. The operating system used is SUSE Linux 10.3, and the version number used for the present computations is OpenFOAM 1.5-dev. 1. Numerical method and model 1.1 Governing equations The OpenFOAM toolbox already provides a solver called MRFSimpleFoam for solving the steady- state Reynolds-Averaged Navier-Stokes equations with turbulence models, such as the standard k model. The coupling between velocity and pressure is treated using the SIMPLE method14. The MRFSimpleFoam solver employs the finite-volume technique to discretize the Navier-Stokes equations in the rotating reference frame: =0Ru +2 + =RR R uu u r +Rp u where Ru is flow velocity in rotating frame, rotating frame speed, r position vector, p fluid pressure, fluid density, and the kinematic vis- cosity. 1.2 General Grid Interface (GGI) Due to the interaction between stator and rotor, nts 228 how to cope with the grids and information tran- smission of the coupling parts in the computational domain is a key issue to simulate precisely the flow fields15-17. The frozen rotor method in MRFSimpleFOAM solver is a steady-state formula- tion where the relative positions in rotor and stator are fixed. In the same time frame, the rotor and the stator parts will be meshed separately. For non-stationary turbo-machinery simulations, the relative rotation of mesh parts will necessarily produce non-conformal in- terfaces between the fixed and moving sections. A connection between these meshes is needed in order to simplify the mesh complexity in various turbo-machi- nery simulations and hence reduce the computer time cost. The GGI, developed by Beaudoin and Jasak18can be used for that purpose in OpenFOAM. It is a new coupling interface for OpenFOAM, joining multi- ple non-conformal regions where the patches nodes on each side of the interface do not match. This interface uses weighted interpolation to eva- luate and transmit flow values across a pair of confor- mal or non-conformal coupled patches. The basic GGI interface is similar to a case of “static” sliding inter- faces with the advantage that no remeshing is required for the neighboring cells of the interface. The GGI uses the Sutherland-Hodgman algori- thm12for computing the master and shadow face in- tersection area. Some quick rejection algorithms based on an axis aligned bounding box have been impleme- nted to speed up the search for potential face neigh- bors. Then, in order to rapidly handle the final non- overlapping filtering test, an efficient Hormann- Agathos point-in-polygon algorithm19has been inclu- ded into the separating axis theorem algorithm18. Finally, discretization effects are taken into account in order to properly scale the GGI weighting factors to handle the possible presence of non-overlapping faces and hence keep the GGI interface conservative. 1.3 Boundary and initial conditions While the Partial Differential Equation (PDE) is solved with the finite volume method, a suitable inter- polation scheme of values typically from cell centres to face centres has a great effect on the numerical results, especially for the convection term. The conve- ction scheme of the existing solver is specified as default by limited linear differencing, which is a Total Variation Diminishing (TVD) scheme. Although it offers a second-order accurate discretization scheme for the convection term, it creates an unconditionally unstable discretisation practice20. In order to achieve stability, a fist-order accurate upwind differencing scheme has been introduced and the simulation results show that the TVD scheme can result more easily in iteration divergence and computation failure than the upwind differencing scheme in simulating the pump inner flow. Therefore, TVD scheme is not applicable to simulate the pump inner flow in the OpenFOAM. In this paper, Guassian up-wind scheme is used and can get the satisfactory results in numerical tests. In addition to appropriate discretization schemes, under-relaxation is another important technique used for improving the stability of a computation, particu- larly in solving steady-state problems. Under-relaxa- tion works by limiting the amount, in which a variable changes from one iteration to the next, either by limi- ting the solution matrix and source prior to solving for a field or by modifying the field directly. An under- relaxation factor , 01 specifies the amount of under-relaxation, ranging from none at all for =1 and increasing in strength as 0 . There- fore, selecting an appropriate relaxation factor has great influence on the efficiency of computation. If the relaxation factor is too large, it will lead to divergence of computation easily. If it is too small, the result will converge slowly. Besides, an appropriate relaxation factor depends on the specific problem itself. Thus, there is no instruction about relaxation factor in simu- lating pump inner flow. At the same time, if the rela- xation factors are used by default in the OpenFOAM to examine the pump inner flow, the result will be un- stable. In this paper, the relaxation factors are suitable for simulating the pump inner flow according to +=1up20. At last, the relaxation factors are determined after many tests and the under-relaxation factors of relevant variables (i.e., pressure, momentum, turbulence kinetic energy and turbulence dissipation rate) are 0.3, 0.7, 0.3 and 0.3, respectively. In order to simulate the flow field in and the whole pump, the GGI method is needed to transmit the information between rotor and stator. 1.4 Model A 3-D model of double-blade pump for simula- tion is generated by Pro/E. The suction chamber is designed by semi-spiral method, while the volute is designed by equal velocity moment method and the cross section is rectangular, and type line is the loga- rithmic spiral. The design parameters of the double blades pump are shown in Table 1. Herein the calculation formulas of sn is 3/43.65=snQnHBefore the simulation, studying the grid indepe- ndency and selecting the turbulent model are nece- ssary21,22. The geometry is meshed in hybrid grid by GAMBIT and the OpenFOAM is used to simulate the inner flow in the double-blade pump. The data for stu- dying grid independency are shown in Table 2. If the head difference is smaller than 0.2%, the grid number is acceptable. According to the computation, Scheme 2 meets the need. So Scheme 2 of grid is adopted. The grids are show in Fig.1. nts 229Table 1 The design parameters Parameter Sign Value Flow rate Q (m3/h) 25.86 Head H (m) 2.53 Rotation speed n (r/min) 750 Specific speed sn 111 Suction chamber inlet diametersD (m) 0.08 Impeller inlet diameter iD (m) 0.09 Blade inlet diameter 1D (m) 0.0812 Impeller outlet diameter 2D (m) 0.2 Impeller outlet width 2b (m) 0.047 Blade inlet angle 1 (o) 18.3 Blade outlet angle 2 (o) 30 Volute base circle diameter 3D (m) 0.212 Volute inlet width 3b (m) 0.077 Table 2 Data for studying grid independency Grid number No. Impeller Volute Suction Total Head, H (m)1 618 738 220 175 300 103 1 139 016 2.46034 2 577 913 179 340 255 937 1 013 190 2.45974 3 505 999 143 450 202 830 852 279 2.43180 4 378 565 151 341 99 619 629 525 2.40151 Fig.1 Grids Table 3 Comparison of turbulence models Turbulent model Head, H (m) Standard k 2.45974 RNG k 2.44706 Omega SST 2.42225 The standard k , RNG k and Omega SST turbulence models have been used to simulate the inner flow in centrifugal pumps. With the same grid, the comparison among the three turbulence models was made and the results are shown in Table 3. It is found that compared with the experimental data, the head obtained by standard k model is the most accurate. Therefore, the standard k turbulence model is used to perform the simulation in this paper. For the test region, the impeller passage near the volute tongue is selected. In order to analyze the inner flow better, 7 pieces of plane curve are set in the im- peller mid-height, equidistant from the impeller inlet to the impeller outlet, and 12 points are distributed equidistantly on each curve. All the analyses of post processing in this paper are based on those monito- ring points as shown in Fig.2. Fig.2 Sample points In order to disclose the characteristics effectively, three research schemes are presented. The ratios ( /dQQ) of the flow rate are 0.8, 1.0 and 1.2, respe- ctively. 2. Results and analysis 2.1 Relative velocity distribution The relative velocity distributions are illustrated in Fig.3. It can be seen that from inlet to outlet under the same working condition, there is a low-speed zone near the middle of the pressure side at the inlet, along the direction of speed changed, which can be found in the top view of Fig.3. Then, a back flow vortex appears, with a remarkable jet-wake flow model. Furthermore, the velocities of all points in the low speed zone go upward with the increase of radius and the jet-wake flow feature becomes unnoticeable, fina- lly disappears. On the circle of impeller inlet, the rela- tive velocities decline gradually at first, from the suction side nearby to the pressure side nearby, and then, when it comes close to the pressure side, the velocity goes up again, peaking at the pressure side. With the increase of radius, the variations of velocity near the suction side are less regular than that near the pressure side. However, when starting from the middle of impeller passage, the velocity near the suction side rises gradually with the increase of radius. But the velocity near the pressure side always rise with the increase of radius. Moreover, the velocity gradient near the pres

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