Abstract：The fruits and vegetables big awning volume curtain machine will be the next big awning planter essential machinery equipment and the development direction, it changed the traditional artificial volume curtain operation method, will enhance above efficiency several times compared to the manual control, solved the daily volume to graze animals the curtain the labor intensity, improved the severe winter open-air operation environment, more importantly reduced the volume, has grazed animals the time which the curtain consumed,Lengthened the illumination time.Enhanced the labor efficiency and the economic efficiency greatly.

Nowadays in the market the main supply is one kind is takes a walk about the type volume curtain machine this kind of volume curtain machine use volume curtain machine power the free volume to graze animals the curtain screen, does not need to receive the big awning slope size the limit. But this kind of volume curtain machine structure is complex, the stability is bad, the life is low, also does not suit the length oversized big awning.

What this topic designs is one kind of stationary volume curtain machine, it simulates the manual control,Through winding on rope string tautness and relaxation,The realization grass curtain volume receives and sets.

Its main organization including electric motor, speed reducer, volume curtain installment and so on. This topic emphatically carries on the design to the volume curtain machine speed reducer and the volume curtain installment, causes it in to reduce the cost under the premise to satisfy the ordinary pitch type big awning the request.

Key word Volume curtain machine，Speed reducer，Velocity ratio，Bending strength.

1 绪论1

1.1 本课题研究意义1

1.2 本课题的研究现状1

1.3 设计任务与要求3

1.4 拟解决的关键问题3

1.5 拟采用的研究手段4

2 传动装置的总体设计4

2.1 确定传动方案4

2.2 电动机的选择4

2.3 计算总传动比和分配各级传动比5

2.4 计算传动装置的运动和动力参数5

3 传动机构及零件的设计计算6

3.1 带传动的设计计算6

3.2 减速器的设计计算7

3.2.1 蜗轮蜗杆的设计计算7

3.2.2 蜗杆的设计10

3.2.3 齿轮的设计计算17

3.2.4 传动轴的设计22

3.2.5 输出轴的设计29

3.2.6 箱体的设计36

3.3 卷动机构的设计38

3.3.1 卷绳管的设计计算38

3.3.2 绞盘的设计计算41

3.3.3 滑动轴承的设计43

3.3.4 法兰连接的设计43

4 结论46

参考文献47

致谢49

外文文献原文

译文

1 绪论

1.1 本课题研究意义

随着城乡人民生活水平的提高，冬季栽培鲜菜、鲜果的温室大棚蓬勃发展，其规模越来越大。但是，在温室大棚作业中，卷铺草帘是最费时费工的主要作业环节之一，尤其在严寒冬季的凌晨和傍晚，在寒风刺骨的恶劣条件下，农民站在大棚顶上从事着艰苦笨重的草帘卷铺劳动，情况可想而知。对于一个长80米大棚来说，每天都要在早上拉启、傍晚放下，各要用大约40分钟左右。严格的来说，冬天里的阳光和温度是“果蔬大棚”中作物正常生长所依赖的珍贵资源。农民要争分夺秒，辛苦是可想而知的[1]。但这仍然解决不了问题，由于“果蔬大棚”保温帘开启和关闭时间相对集中，引起的劳力不足和耗用时间过长，已经严重制约了“果蔬大棚”的产量效益和发展空间。

电动卷帘机的出现则彻底解决了人工卷铺帘子带来的一系列不便。使用电动卷帘机，可随时启动，延长了光照时间，增加了光合作用，更重要的是节省劳动时间，减轻了劳动强度。日光温室在深冬生产过程中，每一千平方米温室人工控帘约需1.5小时，而卷帘机只需5分钟左右，太阳落山前，人工放帘需用约1小时左右，由此看来，每天若用卷帘机起放帘子，比人工节约近2小时的时间。同时延长了室内宝贵的光照时间，增加了光合作用时间。另外，使用电动卷帘机对草帘、棉帘保护性好，延长了草帘、棉帘的使用寿命，既降低生产成本，同时因其整体起放，其抗风能力也大大增强。总体上可使农民能比较轻松地用更多的精力提高对蔬菜进行管理，提高品质、扩大规模[2]。

因此，开发经济、实用的电动卷帘机是一项很好的研究课题。

1.2 本课题的研究现状

目前国内生产的卷帘机主要有两种工作方式[3]：一种是固定式，卷帘机固定在大棚后墙的砖垛上，它模拟人工操作，通过缠绕在轴上的绳子的拉紧和放松。利用机械动力把草帘子卷上去，利用大棚的坡度和草帘子的重量往下滚放草帘子。该种型号的卷帘机造价较高，大棚要有一定的坡度，如果棚面坡度太平，草帘子滚不下来，当风大时容易乱绳并影响工作，且安装复杂。另一种是走动式，这种卷帘机由悬臂杆、支撑杆、电机、减速机构和卷帘轴等组成。其工作方式是采用机械手的原理，利用卷帘机的动力上下自由卷放草帘子，不必受大棚坡度大小的限制。但存在以下不足，悬臂杆和支撑杆稳定性差，对草帘整体弯度要求较高，不易满足长度较大的大棚，且其卷帘轴被焊接成整体构件，拆装不方便。

对于较常见的80米长的果蔬大棚，通过文献检索，有一些满足要求的卷帘机械，现将代表性的结构特点分析如下。

图1[4]是一种卷帘机的使用状态示意图，该卷帘机采用固定式结构，主要由工作电机及固定机构，减速机，卷绳管，卷帘绳，螺栓，轴承等组成。其工作原理为电机通过减速箱减速，使输出轴与卷绳管连接，带动卷绳管转动，卷绳管与卷帘绳一端固定，电机工作，卷绳管带动卷帘绳卷起，卷帘绳带动草帘卷起，完成卷的过程。电动反转，卷帘在自身重力作用下沿绳放下，完成放的过程。其中卷帘机的电机和减速机分别固定在一电机支杆上，电机支杆的下端固定在温室的墙上。大棚卷帘机包括多个卷绳管支承机构，卷绳管直接与减速箱的输出轴相连。卷绳管通过支架固定。支架通过螺栓固定在大棚的顶墙上。卷帘绳一端套在卷绳轴上，另一端绕过卷轴大棚顶端。其中电机通过减速机予以减速，带动整体。优点：结构简单，以电机驱动，卷帘卷起速度快，省工省力，适合大面积作业。

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内容简介：: 中北大学2006届本科毕业设计说明书外文文献原文Helical，Worm and Bevel GearsIn the force analysis of spur gars, the forces are assumed to act in a single plain. In this lesson we shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a righthand helix and the other a lefthand helix. The shape of the tooth is an involute helicoids. If a piece of paper cut in the shape of a parallclogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoids.The initial contact of spurgear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point,which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth.It is this gradual engagement of the teeth and the smooth transfer of load from one tooth to another ,which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear（herringbone）is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reaction and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossedhelical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical gears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is no difference between a crossed helical gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is, a right-hand driver goes with a right hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should he used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature, nature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears. Worn gearing are either single or double enveloping. A single enveloping gearing is one in which the gear wraps around or partially encloses the worm, A gearing in which each element partially encloses the other is, of course, a double enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 9O deg. shaft angle.When gears are to be used to transmit motion between intersecting shafts, some form of bevel gear is required. Although bevel gears are usually made for a shaft angle of 9O deg., they may be produced for almost any shaft angle. The teeth may be east, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of the teeth. Another difficulty, which occurs in predicting the stress in bevel gear teeth, is the fact that the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of spur gears, however, they become noisy at higher values of the pitch-line velocity. In these eases it is often good design practice to go to he spiral bevel gear, which is the bevel counterpart of the helical gear, as in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered. It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gearsSAND CASTINGMost metal casting are made by pouring molten metal into a prepared cavity and allowing it to solidify. The process dates from antiquity. The largest bronze statue in existence to-day is the great Sun Buddha in Nara, Japan. Cast in the eighth century, it weighs 551 tons(500 metric tons) and is more than 71 ft (21m) high. Artisans of the Shang Dynasty in China ( 1766 - 1222B. C. ) created art works of bronze with delicate filigree as sophisticated as anything that is designed and produced today.There are many casting processes available today, mid selecting the best one to produced particular part depends on several basic factors, such as cost, size. production rate. finish, tolerance, section thickness, physical-mechanical properties, intricacy of design mach inability, and weld ability.Sand casting. the oldest and still the most widely used casting process. will be presented in more detail than the other processes since many of the concepts carry over into those processes as well.Green Sand Green sand generally consists of silica sand and additives coated by rubbing the sand grains together with clay uniformly wetted with water. More stable and refractory sands have been developed, such as fused silica, zircon, and mullets, which replace lower-cost silica and have only 2% linear expansion at ferrous metal temperatures. Also, relatively un-stable water and clay bonds are being replaced with synthetic resins, which are much mores table at elevated temperatures.Green sand molding is used to produce a wide variety of castings in sizes of less than around to as large as several tons. This versatile process is applicable to both ferrous and nonferrous materials.Green sand can be used to produce intricate molds since it provides for rapid collapsibility: that is, the mold is much less resistant to the contraction of the casting as it solidifies than are other molding processes. This results in less stress and strain in the casting.The sand is rammed or compacted around the pattern high a variety of methods, including hand or pneumatic-tool ramming, jolting (abrupt mechanical shaking), squeezing (com-pressing the top and bottom mold surfaces), and driving the sand into the mold at high velocities (sad slinging). Sand slings are usually resented for use in making very large casting where great volumes of sand are handled.For smaller casting, a two-part metal box or flask referred to as a cope and drag issued. First the pattern is positioned on a mold board. and the drag or lower half of the flask is positioned over it. Parting powder is sprinkled on the paten and the box is filled with sand. A jolt squeeze machine quicky compacts the sand. The flask is then turned over and again parting powder is dusted on it. The cope is then positioned on the top half of the flask and is filled with sand, and the two-part mold with the patter board sandwiched in between is squeezed.PatternsPatterns for sand casting have traditionally been made of wood or metal. However, it has been found that wood patterns change as much as 3% due to heat and moisture. This factor alone would put many casting out of acceptable tolerance for more exacting specifications. Now, patterns are often made from epoxies and from cold-setting rubber with stabilizing inserts. Patterns of simple design, with one or more flat surface, can be molded in one piece, provided that they can be withdrawn without disturbing the compacted sand. Other patterns may be split into two or more parts to facilitate their removal from the sand when using two-part flasks. The pattern must be tapered to permit easy removal from the sand. The taper is referred to as draft. When a part does not have some natural draft, it must be added. A more recent innovation in patterns for sand casting has been to make them out of foamed polystyrene that is vaporized by the molten metal. This type of casting, known as the full-mold process, does not require pattern draft.Spruces, Runners, and Gates.Access to the mold cavity for entry of the molten metal is provided by sprees, runners, and gates, as shown in Fig. 7 I. A pouring basin can be carved in the sand at the top of the spree, or a pour box, which provides a large opening, may be laid over the spree to facilitate pouring. After the metal is poured, it cools most rapidly in the sand mold. Thus the outer surface forms a shell that permits the still molten metal near the center to flow toward it. As a result, the last portion of the casting to freeze will be deficient in metal and, in the absence oaf supplemental metal-feed source, will result in some form of shrinkage.2 This shrinkage may take the form of gross shrinkage (large cavities) or the more subtle micro shrinkage ( finely dispersed porosity). These porous spots can be avoided by the use of risers, as shown in Fig.7-1, which provide molten metal to make up for shrinkage losses.CoresCores are placed in molds wherever it is necessary to preserve the space it occupies in the mold as a void in the resulting castings. As sown in Fig.7-1, the core will be put in place after the pastern is removed. To ensure its proper location, the pattern has extensions known as core prints that leave cavities in the mold into which the core is seated. Sometimes the core may be molded integrally with the green sand and is then referred to as a green-sand core. Generally, the core is made of sand bonded with core oil, some organic bonding materials, and water. These materials are thoroughly blended and placed in a mold or core box. After forming, they are removed and baked at 350to 450F ( 177to 232C). Cores that consist of two or more parts are pasted together after baking.CO2 CoresCO2 cores are made by ramming up moist sand in a core box. Sodium silicate is used as a binder, which is quickly hardened by blowing CO2 gas over it. The C02 system has the advantage of making the cores immediately available.Pouring the MetalSeveral types of containers are used to move the molten metal from the furnace to the pouring area. Large castings of the floor-and-pit type are poured with a ladle that has a plug in the button, or, as it is called, a bottom-pouring ladle. It is also employed in mechanized operations where the molds are moved along a line and each is poured as it is momentarily stopped beneath the large bottom-pour ladle.ladles used for pouring ferrous metals are lined with a high alumina-content refractory. After long use and oxidation, it can be broken out and replaced. Ladles used in handling ferrous metals most be preheated with gas flames to approximately 2600 to 2700F ( 1427 to 1482C) before filling. Once the ladle is filled, it is used constantly until it has been emptied.For nonferrous metals, simple clay-graphite crucibles are used. While they are quite susceptible to breakage, they are very resistant to the metal and will hold up a long time under normal condition. They usually do not require preheating, although care must he taken to avoid moisture pickup. For this reason they are sometimes baked out to assure dryness.The pouring process must he carefully controlled, since the temperature of the melt greatly affects the degree of liquid contraction before solidification, the rate of solidification, which in turn affects the around of columnar growth present at the mold wall, the extent and nature of the dendrite growth, the degree of alloy burnout, and the feeding characteristics of the rise ring system.Finishing OperationsAfter the castings have solidified and cooled somewhat. they are placed on a shakeout table or grating on which the sand mold is broken up, leaving the casting free to be picked out. The casting is then taken to the finishing room where the gates and risers are removed. Small gates and risers may he broken off with a hammer if the material is bride. Larger ones requiem sawing, cutting with a roach, or shearing. Unwanted metal protrusions such as fins, bosses, and small portions of gates and risers need to be smoothed off to blend with the surface. Most of this work is done with a heavy-duty grinder and the process is known as snagging or snag grinding. On large castings it is easier to move the grinder than the work, so swing-type grinders are used. Smaller castings are brought to stand or bench-type grinders. Hans and pneumatic chisels are also used to trim castings. A more recent method of removing excess metal from famous castings is with a carbon air torch. This consists of a carbon rod and high-amperage current with a stream of compressed air blowing at the base of it. This oxidizes and removes the metal as soon as it is molten, In many foundries this method has replaced nearly all chipping and grinding operation.译文斜齿轮、蜗杆蜗轮和锥齿轮在直齿圆柱齿轮的受力分析中，是假定各力作用在单一平面的。在这一课题中，我们将研究作用力具有三维坐标的齿轮。因此，在斜齿轮的情况下，其齿向是不平行于回转轴线的。而在锥齿轮的情况中各回转轴线互相不平行。像我们将要讨论的那样，尚有其他道理需要学习、掌握。斜齿轮用于传递平行轴之间的运动。倾斜角度每个齿轮都一样，但一个必须右旋斜齿，而另一个必须是左旋斜齿。齿的形状是一渐开线螺旋面。如果一张被剪成平行四边形(矩形)的纸张包围在齿轮圆柱体上，纸上印出齿的角刃边就变成斜线。如果我展开这张纸，在斜角刃边上的每一个点就发生一渐开线曲线。直齿圆柱齿轮轮齿的初始接触处是跨过整个齿面而伸展开来的线。斜齿轮轮齿的初始接触是一点，当齿进入更多的啮台时，它就变成线。在直齿圆柱齿轮中，接触线是平行于回转轴线的。在斜齿轮中，该线是跨过齿面的对角线。它是轮齿逐渐进行啮台并平稳地从一个齿到另一个齿传递运动，那样就使斜齿轮具有高速重载下平稳传递运动的能力。斜齿轮使轴的轴承承受径向和轴向力。当轴向推力变得大了或由于别的原因而产生某些影响时，那就可以使用人字齿轮。双斜齿轮(人字齿轮)是与反向的并排地装在同一轴上的两个斜齿轮等敬。他们产生相反的轴向推力作用，这样就消除了轴向推力。当两个或更多的单向齿斜齿轮被装在同一轴上时，齿轮的齿向应作选择，以便产生最小的轴向推力。交错轴斜齿轮或螺旋齿轮，他们的轴中心线既不相交也不平行。交错轴斜齿轮的齿彼此之间发生点接触，它随着齿轮的磨合而变成线接触。因此他们只能传递小的载荷和主要用于仪器设备中，而且肯定不能推荐在动力传动中使用。交错轴斜齿轮与斜齿轮之间在被安装后互相啮合之前是没有任何区别的。它们是以同样的方法进行制造。一对相啮合的交错轴斜齿轮通常具有同样的齿向，即左旋主动齿轮跟右旋从动齿轮相啮舍。在交错轴斜齿设计中，当该齿的斜角相等时所产生滑移速度最小。然而当该齿的斜角不相等时，如果两个齿轮具有相同齿向的话，大斜角齿轮应该用作主动齿轮。蜗轮与交错轴斜齿轮相似。小齿轮即蜗杆具有较小的齿数，通常是一到四齿由于它们完全缠绕在节圆柱上，因此它们又被称为螺纹齿。与其相配的齿轮叫做蜗轮，蜗轮不是真正的斜齿轮。蜗杆和蜗轮通常是用于向垂直相交轴之间的传动提供大的角速度减速比。蜗轮不是斜齿轮，因为其齿顶面做成中凹形状以适配蜗杆曲率，目的是要形成线接触而不是点接触。然而蜗杆蜗轮传动机构中存在齿问有较大滑移速度的缺点，正像变错轴斜齿轮那样。蜗杆蜗轮机构有单包围和双包围机构。单包围机构就是蜗轮包裹着蜗杆或部分地包围着蜗杆的一种机构。当然，如果每个构件各自局部地包围着对方的蜗轮机构就是双包围蜗轮蜗杆机构。这两者之间的重要区别是，在双包围蜗轮组的轮齿间有面接触，而在单包围蜗轮组的轮齿间只有线接触。一个装置中的蜗杆和蜗轮正像交错轴斜齿轮那样具有相同的齿向，但是其斜齿齿角的角度是极不相同的。蜗杆上的齿斜角度通常很大，而蜗轮上的则极小。因此惯常规定蜗杆的导角，那就是蜗杆齿斜角的余角；也规定了蜗轮上的齿斜角，该两角之和就等于90。的轴线交角。当齿轮要用来传递相交轴之网的运动时，就需要某种形式的锥齿轮。虽然锥齿轮通常制造成能构成90度轴交角，但它们也可产生任何角度的轴交角。轮齿可以铸出、铣制或滚切加工。仅就滚齿而言就可达一级精度。在典型的锥齿轮安装中，其中一个锥齿轮常常装于支承的外侧。这意味着轴的挠曲情况更加明显而使在轮齿接触上具有更大的影响。另外一个难题，发生在难于预示锥齿轮轮齿上的应力实际上是由于轮齿被加工成锥状造成的。直齿锥齿轮易于设计且制造简单，如果他们安装的精密而确定，在运转中会产生良好效果。然而在直齿圆柱齿轮情况下，在节线速度较高时，他们将发出噪音。在这些情况下，通常设计使用螺旋锥齿轮，实践证明是切实可行的，那是和配对斜齿轮很相似的配对锥齿轮。当在斜齿轮情况下，螺旋锥齿轮比直齿轮能产生平稳得多的啮合作用，因此碰到高速运转的场合那是很有用的。当在汽车的各种不同用途中，有一个带偏心轴的类似锥齿轮的机构，那是常常所希望的。这样的齿轮机构叫做准双曲面齿轮机构，因为他们的节面是双曲回转面。这种齿轮之间的轮齿作用是沿着一根直线上产生滚动与滑动相结合的运动并和蜗轮蜗杆的轮齿作用有着更多的共同之处。砂型铸造大多数金属铸件。是通过将熔化的金属注入预先做好的型腔凝固而成的，这种方法可溯及古代, 现存最大的青铜铸件是日本奈良市的太阳大佛它铸于八世纪，重551(美国)叫(500吨)高度超过71英尺(21米) 小国商朝(公元前17661222年)的工匠们制造的精美的青铜制品其复杂程度可与当代设计制造的工艺品媲美目前，有许多铸造方法，对特定铸件所选择的最好的铸造方法，取决于几个基本因素。比如成本、尺寸、生产率、光洁度(我国标准名词术语现称作表面粗糙度译者)、公差、截面厚度、物理化学降性、设计难度、可加工件和可焊件等砂则铸造是最古老且仍广泛应用的铸造方法。本文将详细地介绍这种方法，因为它的许多概念也适用于其他方法型砂型砂通常含有石英砂和添加剂、通过砂粒与用水均匀溅湿的粘土的搅拌、使砂粒及添加剂表面包复,层粘结薄膜更稳定耐熔的砂子，如熔融石英砂、钴土砂、

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