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下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 11970985目录摘 要 .1ABSTRACT .21 绪论 .31.1 课题的研究目的和意义 .31.2 课题研究的内容 .32 港口单臂架 MQ4035 门座起重机总体设计 .42.1 性能参数 .42.2 确定主要工作机构和金属结构的形式 .52.3 载荷的计算 .122.4 轮压的计算 .212.5 整机抗倾覆稳定性计算 .243 回转机构设计及计算 .293.1 概述 .293.2 滚动轴承式回转支承选型计算： .303.3 回转支承装置计算 .323.4 回转驱动机构设计 .374 总结与展望 .454.1 工作总结 .454.2 工作展望 .45参考文献 .46致 谢 .46附录一 文献检索 .48下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709851摘 要近年来，随着我国实力的不断进步，各行各业都有了巨大的发展，在港口运输方面，以门座起重机为主要工作单位的运输机械占据的地位也越来越重要，而其中的回转部分的设计也越来越受到人们的关注，回转部分的好坏，对其总体性能的影响是不言而喻的，因此，有必要对其回转机构的设计进行一次探讨。本文以 MQ4035 单臂架门座起重机为例，叙述了门座式起重机总体设计的一般过程，并对其回转机构进行了初步设计，并且给出了回转机构及其总体的 CAD 图纸，结论证明，本文所确定的门座起重机各项参数可以通过整机稳定性验算，回转机构所选择的电机和轴承符合要求。本文借鉴了以往这方面学者的经验，也可以对于后来人的学习提供一些参考。关键词：门座起重机；回转机构；总体计算。下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709852AbstractIn recent years, with the continuous progress of our country, various trades and industries have a huge development, in the port transport, the portal crane as the main transport machinery have a more and more important position, the design of the rotating part of the crane also have been paid attention by more and more people, the good or bad of the circumgyrate mechanism is very important to the portal crane, therefore, it is necessary to carry out a discussion about the design of the rotating mechanism.This paper takes the MQ4035 portal crane as an example to describe the general process of portal cranes design, and make a design of the rotating mechanism. We also give the CAD drawings of the crane and the rotating mechanism. The result reveals that the stability of the whole crane can meet the requirements, the motor and bearings in the rotating mechanism meet the requirements.This article draws on the experience of the scholars in this part, then also can provides some reference to the people.Key Words：portal crane；rotating mechanism ；load computation.下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709853下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709854下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 1197098551 绪论1.1 课题的研究目的和意义随着世界经济全球化的快速发展和我国对外贸易量的持续增长，港口业务迅速发展，决定了港口起重机械向高速化、自动化、智能化发展，对设计和性能要求也越来越高：质量轻、刚度好、工作空间大、工作速度快、作业效率高。因此港口装卸机械的设计计算方法需要不断的更新、充实和完善，使港口机械向更注重功能性、经济性、可靠性和安全性的方向发展。根据国内外起重机械的发展，今后一个时期，港口起重机的主要发展趋势是：1）发展大型、专业的装卸机械。以适应船舶大型化、货物装卸散装化、集装箱化发展需要。2）减轻机械自重，实现起重机械的轻型化，包括采用新的结构型式，新材料，新的传动机构，新工艺等。3）将机械技术与电子技术结合，单机设计与机械化作业系统相结合。将先进的微机控制（PLC 控制）、光纤技术、液压技术等运用到机械的驱动和控制系统，以改善起重机工作性能。4）新的装卸搬运技术的研究。包括用自动存取系统的自动化仓库，气垫搬运技术等。5）标准化，系统化，规范化。6）人际工作学的应用。1.2 课题研究的内容本课题以 MQ4035 型门座式起重机为研究对象，进行整机设计计算和回转机构的设计。首先根据给定的技术参数，进行门座起重机的总体设计技术；然后进行其回转支承装置和回转驱动装置的计算。具体工作如下：1）根据课题所给的主要技术参数，参照起重机设计手册，对门座起重机进行总体方案选型和总体设计技术，对起升、变幅、回转、运行机构进行初步选型和布置，绘制门座起重机 MQ4035 的总图。2）根据所给定的参数，进行回转机构的计算，包括其支承装置和驱动装置的计算，选择电动机和联轴器、制动器。下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 1197098562 港口单臂架 MQ4035 门座起重机总体设计2.1 性能参数起重机的技术参数表征起重机的作业能力，是设计起重机的基本依据。设计港口起重机械时，需要根据具体情况确定起重机的主要性能参数。本次设计的 MQ4035 门座起重机主要性能参数见表 2.11。表 2.1 主要性能参数表项目名称 性能参数起重量 40t最大幅度：35m工作幅度最小幅度：11.5m轨上：25m起升高度轨下：15m起升机构：25m/min变幅机构：24m/min回转机构：1r/min机构工作速度运行机构：25m/min整机：A6起升机构：M6变幅机构：M6回转机构：M6机构工作级别运行机构：M4轨距/基距 10.5/10.5m工作状态最大风压 250N/m2非工作状态最大风压 1560 N/m2工作时最大轮压 240KN轨道型号 QU80电源 380V/50Hz下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 1197098572.2 确定主要工作机构和金属结构的形式单臂架门座起重机是简易式门座起重机，主要由钢结构、起升机构、变幅机构、回转机构、大车运行机构、吊具装置、电气设备及其必要的安全和辅助设备组成。在钢丝绳缠绕系统中，采用补偿滑轮钢丝绳缠绕系统或补偿卷筒钢丝绳缠绕系统，在变幅过程中起升吊点保持近水平状态，使用状态安全可靠。钢结构构造简单，主要有臂架、人字架、回转平台以及门架组成 2。2.2.1 确定主要工作机构形式1）起升机构组成及工作原理起升机构是用来实现货物升降的工作机构，它是起重机械中不可缺少的部分，是起重机中最基本重要的机构，其工作性能的优劣直接影响起重机的技术性能。起升机构一般由驱动装置、传动装置、制动装置、卷绕系统、取物装置以及安全辅助装置等组成。驱动装置包括电动机、联轴器、制动器、减速器、卷筒等部件。钢丝绳卷绕系统包括钢丝绳、卷筒、定滑轮和动滑轮。取物装置有吊钩、吊环、抓斗、电磁吸盘、吊具、挂梁等多种型式。安全保护装置有超负荷限制器、起升高度限位器、下降深度限位器、超速保护开关等，根据实际需要配用。起升机构的总体布置方案在很大程度上取决于驱动装置形式。在港口起重机中，起重机的驱动型式有两种：集中驱动和分别驱动。港口起重机常用的驱动装置型式为电机分别驱动，各机构由独立的电机驱动，分组性好，布置、安装维修都比较方便，操纵控制系统简单。电动机与卷筒并列布置是吊钩起重机应用最多的布置型式，电动机通过标准减速器带动卷筒转动，其布置形式如图 2.1。电动机输出的扭矩经减速器放大后驱动卷筒旋转，使钢丝绳绕上卷筒或从卷筒中放出，从而使吊具升降，实现货物的起升动作。卷筒的正反转通过改变电动机的转向实现，机构运动的停止或使货物悬吊在空中一定位置依靠制动装置来实现。起升机构的钢丝绳卷绕系统是起升机构传动的一部分，起着转换运动形式的作用。门座起重常用的起升钢丝绳卷绕系统形式如图 2.2 所示，钢丝绳两头固定在卷筒上，由卷筒引出通过人字架或转柱上的导向滑轮 1 至臂架或象鼻梁尾部的导向滑轮 2，再通过臂架或象鼻梁头部的定滑轮 3 引至吊钩装置的动滑轮组 4。不同的起重量配置由不同数量的定滑轮或动滑轮组成的滑轮组。对于单臂架门座起重机，臂架变幅时，为了使物品保持水平移动或近似做水平位移动，必须对起升钢丝绳进行补偿。本文所采用的即为带补偿滑轮组的钢丝绳卷绕系统，如图 2.3 所示。下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709858图 2.1 起升驱动机构示意图图 2.2 门座起重机起升绳典型卷绕形式 图 2.3 带有绳索补偿的起升绳卷绕系统2）变幅机构组成及工作原理在起重机中用来改变幅度的机构称为变幅机构，对回转类型的起重机，从取物装置中心线到回转中心线的距离称为起重机的幅度。变幅机构是用来实现取物装置幅度改变的工作机构，由臂架系统和变幅驱动系统组成。变幅机构的主要作用是：通过改变幅度来改变取物装置的工作位置，以实现起重机起重能力的调整，或者装卸路线的调整；通过改变幅度扩大起重机的作用范围，与起升、回转机构协调工作，使取物装置的工作范围形成一环形工作空间，以提高起重机的生产率。在装卸类型的起重机中，一般采用较下载后包含有 CAD 图纸和说明书,咨询 Q 197216396 或 119709859高的变幅速度以提高装卸生产率。本设计中，采用具有补偿系统的桁架式单臂架系统，齿条式变幅驱动机构。桁架式单臂架自重轻，幅度大，设计和制造方便。具有补偿系统的变幅机构可使吊重和臂架系统的重心在变幅过程中实现沿水平线或接近水平线轨迹运动，以减小吊重和自重引起的变幅阻力，从而减少变幅功耗。本机变幅机构采用单根齿条驱动变幅，传动系统主要由电动机、传动轴、制动器、减速器、联轴器、小齿轮、齿条和摇架等组成。当电机工作时，齿条作直线往复运动，以驱动组合臂架摆动而适应各幅度位置的变化。摇架作为运动齿条的导向装置，可绕铰点转动。小齿轮与齿条的啮合间隙用三个带有偏心轴的导向轮来调整。电动机与减速器的连接采用浮动传动轴。在减速器的高速轴端装有一套制动器，在臂架的下铰点装有减速开关，在摇架上装有两级终端限位保护，在齿条箱的终端还设置有安全档块。变幅机构驱动传递路径为：变频电机鼓型齿形联轴器浮动轴鼓型带制动盘齿形联轴器减速器低速轴鼓型齿形联轴器齿条支承摇架齿条。它采用变频调速的方式，由电控 PLC、变频器实现，具有良好的调速性能。变幅机构传动简图如图 2.4 所示。图 2.4 变幅机构示意图1-变频电机；2- 高速轴齿形联轴器；3-浮动轴；4- 盘式制动器；5-高速轴带制动盘联轴器；Engineering, 2011, 3, 935-941 doi:10.4236/eng.2011.39115 Published Online September 2011 (http:/www.SciRP.org/journal/eng) Cop yrigh t 20 11 S ciRes . ENG Stress Analysis of Crane Hook and Validation by Photo-Elasticity Rashmi Uddanwadiker Department Mechanical Engineering, Visvesvaraya National Institute of Technology, Nagpur, India E-mail: rashmiu71 Received July 27, 2011; revised August 12, 2011; accepted August 26, 2011 Abstract Crane Hooks are highly liable components and are always subjected to failure due to accumulation of large amount of stresses which can eventually lead to its failure. To study the stress pattern of crane hook in its loaded condition, a solid model of crane hook is prepared with the help of CMM and CAD software. Real time pattern of stress concentration in 3D model of crane hook is obtained. The stress distribution pattern is verified for its correctness on an acrylic model of crane hook using Diffused light Polariscope set up. By predicting the stress concentration area, the shape of the crane is modified to increase its working life and reduce the failure rates. Keywords: Photo-Elasticity, Crane Hook, Finite Element Method, Curved Beam, Stress Optic Law 1. Introduction Crane Hooks are highly liable components that are typi- cally used for industrial purposes. It is basically a hoist- ing fixture designed to engage a ring or link of a lifting chain or the pin of a shackle or cable socket and must follow the health and safety guidelines 1-4. Thus, such an important component in an industry must be manu- factured and designed in a way so as to deliver maximum performance without failure. Thus, the aim of the project is to study the stress distribution pattern of a crane hook using finite element method and verify the results using Photo elasticity. 2. Failure of Crane Hook To minimize the failure of crane hook 5, the stress in- duced in it must be studied. Crane is subjected to con- tinuous loading and unloading. This causes fatigue of the crane hook but the fatigue cycle is very low 6. If a crack is developed in the crane hook, it can cause frac- ture of the hook and lead to serious accident. In ductile fracture, the crack propagates continuously and is more easily detectible and hence preferred over brittle fracture. In brittle fracture, there is sudden propagation of the crack and hook fails suddenly 7. This type of fracture is very dangerous as it is difficult to detect. Strain aging embrittlement 8 due to continuous loading and unloading changes the microstructure. Bending stress and tensile stress, weakening of hook due to wear, plastic deformation due to overloading, and ex- cessive thermal stresses are some of the other reasons for failure. Hence continuous use of crane hooks may in- crease the magnitude of these stresses and ultimately result in failure of the hook. 3. Methodology of Stress Analysis The analysis is carried out in two phase: 1) Finite ele- ment stress analysis of an approximate (acrylic) model and its verification by photo elasticity theory 2) Analyti- cal analysis assuming hook as a curved beam and its verification using Finite element analysis of the exact hook. To establish the finite element procedure a virtual model similar to the acrylic mode is prepared in ANSYS and the results of stress analysis are cross checked with that of photo elasticity. After establishing the procedure a virtual model similar to actual crane hook sample is cre- ated using CAD software and the results of finite element analysis are now verified with that of analytical method. 4. Finite Element Analysis (FEA) Finite element method 9,10 has become a powerful tool for numerical solution of a wide range of engineering problems. For the stress analysis of the acrylic model of R. UDDANWADIKER 936crane hook the outer geometry or profile of the model is drawn in ANSYS 11.0. It is then extruded to 9.885 mm to form a 3-D model of hook. Here 9.885 is the average thickness of the model. Material properties and element type are fed and the model is meshed using smart size option with the global size of the element as 3. Loading and constraint are applied to the meshed model as shown in the Figure 1 and the finite element model is then solved. Principal stress and von mises stress patterns are thus obtained as shown in Figure 2. 5. Theory of Photo Elasticity For the verification of the results obtained from FEM, the experimentation is conducted using the concept of photo elasticity. The concept is used to determine stress distribution and stress concentration factors in irregular geometries. The method is based on the property of bire- fringence, which is exhibited by certain transparent ma- terials. Birefringence is a property by virtue of which a ray of light passing through a birefringent material ex- periences two refractive indices. Thus, a crane hook model made out of such material is selected for the. Figure 1. Meshed constraint model. Figure 2. Principle stresses in the model. study. T t of the 5.1. Stress Optic Law When plane polarized light passes through a photo elas- he model has geometry similar to tha structure on which stress analysis is to be performed. This ensures that the state of stress in the model is simi- lar to that of the structure. tic material, it resolves along the two principal stress directions and each of these components experiences different refractive indices 11. The difference in the refractive indices leads to a relative phase retardation between the two component waves. The magnitude of the relative retardation is given by the stress optic law: RC t 11 22 where R is the induced retardation, C is the stress optic po- la ation of disc is done to find the material fringe va w value, coefficient, t is the specimen thickness, 11is the first principal stress, and 22is the second principal stress. The two waves are then brought together in a riscope set up. Thus, the state of stress at various points in the material can be determined by studying the fringe pattern. Calibr lue f . An acrylic model of disc is taken and subjected to compressive load in the circular polariscope setup. Figure 3 shows fringe pattern on a loaded disc. Values of loads are noted down for various fringe orders Using the formula f = 8P/ DN = 11.15 here P = Load applied at particular fringe N = Fringe order at corresponding load D = diameter of the disc = 7.01 cm Figure 3. stress pattern of photo elastic model under so- dium light. Cop yrigh t 20 11 S ciRes . ENG R. UDDANWADIKER 937 gnitude at a point is given by: ( 1 2 )/2 = N f / re 1= major principal stress, 2= minor principal 6. Results For the approximate model of crane hook, stresses in- maximum principal stress Stress ma t whe stress, t = thickness of hook. duced during finite element analysis are compared with that of photo elasticity experiment. For the acrylic model of crane hook the results are as under: ANSYS v/s Experimental As shown in Figure 4, (a) (b) Figure 4. Stress distribution pattern for acrylic model (a) 5 N/mm 2 while that e reasons for variation might be due to the fact th sults confirm that the FEA procedure is w Since the crane hook is a curved beam 12, simple the- Using fem; (b) Using photo-elasticity. value obtained from ANSYS = 12.3 obtained experimentally = 11.121 N/mm 2 . The results are closely in agreement with a very small percentage error = 5.76%. Possibl at it is difficult to find the magnitude of stress exactly on the plane of the fringe closest to inner surface and thus the value 12.35 may not be accurate. Figure 5 shows the exact location of maximum stress on the ap- proximate model of crane hook as obtained from AN- SYS software. The above re ell established and can be used for complex and accu- rate models also. Hence in the second phase of the study, analytical calculations are carried out for the exact model of crane hook and the results are validated from that of ANSYS. 7. Analytical Method ory of bending for shallow, straight beam does not yield accurate results. Stress distribution across the depth of such beam, subjected to pure bending, is non linear (to be precise, hyperbolic) and the position of the neutral surface is displaced from the centroidal surface towards the centre of curvature. In case of hooks as shown in Figure 6, the members are not slender but rather have a sharp curve and their cross-sectional dimensions are large compared to their radius of curvature. Figure 5. Variations due to limitations. Cop yrigh t 20 11 S ciRes . ENG R. UDDANWADIKER 938Neutral Surface Centroidal Surface M M r n r c e cg c c c d d b c o c i r o y c b d Figure 6. Curved beam with its cross section area. The strain at a radius r = 11 22 d n rr dd 0 d 1 d d(where ) () .where . . . . AA n A c A cn n n n n i i i o o o n AE A r A Ar r rr A A MEA e err rA e M rr Mr r My yrr Ae Ae r y Mc Aer Mc Aer RC t d rr r The strain is clearly zero at the neutral axis and is maximum at the outer radius of the beam. Using the rela- tionship of stress/strain = E, the normal stress is simply. n d EE rr r The location of the neutral axis is obtained by equating the product of the normal stress and the area elements over the whole area to 0 d dd n AA rr AE A r 0 reduces to d n A A Ar r d n A A r A r Therefore, The stress resulting from an applied bending moment is d the fact, that the resisting moment is sim erived from ply the integral of the product of moment arm over whole section from the neutral axis and dA. The maxi- mum stress occurs at either the inner or outer surface. The centroid of the section is 1 d rr A c A A Therefore, dwhere cn M EA e err .where n n n n rA e M rr Mrr My yrr Ae Ae r y The maximum stress occurs at either the inner or ou surface: Stress at inner surface ter . , . i i M c A i er Stress at outer surface . . . o M c o A o er The curved beam flexure form la is in reasonable agreement for beams with a ratio of curvature to beam dept r h 8(a ured for the modeling in ANSYS software. u h ( c / ) 5 (rectangular section). As this ratio in- creases, the difference between the maximum stress cal- culated by curved beam formula and the normal beam formula reduces. The above equations are valid for pure bending. In case of crane hooks, the bending moment is due to forces acting on one side of the section under con- sideration. For calculations the area of cross section is assumed to be trapezoidal 13. Values of stresses as shown in Figure 7 are found out at the A-A section as it is the section where maximum stress is induced. 8. Finite Element Method for the Exact Model A crane hook prepared by forging, as shown in Figure ), is proc Using digital Coordinate Measuring Machine (CMM) the cloud points are obtained and the model is prepared in Cop yrigh t 20 11 S ciRes . ENG R. UDDANWADIKER 939 F 50 mm b o b i r 1 r o h A AFigure 7. Analysis of crane hook. Pro-E software. The virtual model prepared in Pro-E software is i llowing e steps of FEM as discussed earlier the stress analysis obtained from analytical calcula- ed in the Section 7, are compared with re- sults obtained by FEA software. .372 N/mm se harmony with a small per- ce ue to the as ch of ensile stress is 150.72 N/mm on the inner su /mm . As shown in Fi 6)/135.46 = 10.12% N/mm ; Stress analyti-= 1.01 % mported in ANSYS environment. Fo th is conducted for the actual model in ANSYS environ- ment and the results are obtained. Figure 8(b) shows the magnitude and location of stress. 9. Results The induced stresses as tions, explain ANSYS v/s analytical Max value obtained analytically=12.35 N/mm 2 while value obtained from ANSYS = 13 2 The results are in clo ntage error = (13.372 12.35)/12.35 = 8.26% Possible reasons for variation might be the d sumption that 1) Loading is considered as point load- ing in analytical calculation while it is taken on a bunnodes in ANSYS. 2) Cross sectional area is assumed to be trapezoidal and 3) Plane sections remain plane after deformation. Using analytical calculations the stress variation yields the results as shown in Figure 9. Maximum t 2 rface of the crane hook and on the outer surface of the hook, compressive stress is 44.23 N 2 gure 9, the stress goes on decreasing from a max value to zero and again increases from zero to a certain value. Innermost point of section: Max stress by ANSYS= 135.46 N/mm 2 ; Max stress analytically= 150.72 N/mm 2 % error= (150.72 135.4 Outermost point of A-A section: Stress by ANSYS= 43.728 2 cally = 44.23 N/mm 2 ; % error = (44.23 43.728)/43.728(a) (b) Figure 8. (a) Actual crane hook; (b) Stresses obtained usin fem. g 2 3 4 5 6 o 158.72 N/mm 2 44.23 N/mm 2Figure 9. Variation of Stress with depth for the actual model. Cop yrigh t 20 11 S ciRes . ENG R. UDDANWADIKER 940 Reasons for variation: Various assumptions made during the analytical cal- culations (discussed earlier). Profile of the hook obtained from Pro-E Modeling software may not be exactly the same as actual one. 10. Conclusions The complete study is an initiative to establish a FEA procedure, by validating the results, for the measurement of stresses. For reducing the failures of hooks the estima-important. Analytical calculation becomes com- re too complicated. rging is preferred to casting as been in casting the molten metal when solidifies, it has some tion of stresses, their magnitudes and possible locations are very plex as the newer designs a Suggestions to reduce failure Manufacturing process: Fothe crane hooks produced from forging are much stronger than that produced by casting. The reason (a) (b) Figure 10. (a) Hook with Material Removed; (b) Hook with Material Removed. residual stresses due to non uniform solidification. Thus casted crane hooks cannot bear high tensile loads. Grain size: The stress bearing capacity depends on the homogeneity of the material i.e. the relative sizes of the grains in various areas of the component. Smaller the grain size better is the stress bearing capacity. So grain refinement process such as normalizing is advisable after forging. Processes such as welding should be avoided as they increase the stress concentration points which eventually lead to failure. Removal of metal from the hook body is not feasible as it increases the amount of stresses in the hook. This is validated by the following illustration: It is clear from the Fig 10(a) that removal of a small amount of material from minimum stress concen- Ca- 6 Fatigue Cycle. /gkstarns/ME417 S. Suresh, “Fatigue Crack dy of the Structural Relaxa- Tion-Induced Embrittlement of Hypoeutectic ZrCuAl Gro ure tration areas increases the stress slightly though reducing the cost of material. The Figure 10(b) validates the fact that when consid- erable amount of material is removed stresses increase by a good enough margin which is not at all feasible. Design improvement: From the stress analysis we have observed the cross section of max stress area. If the area on the inner side of the hook at the portion of max stress is widene