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家用 榨汁机 机电 系统 设计 CAD

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附录一： 选择榨汁机的诚实指南 1930年一个被称为诺曼沃克博士的人发明了一种榨汁机，它首先磨碎和削减生产。由此产生的质量被放入一个亚麻包,放置在液压机,导演汁淹死一个壶嘴。(沃克博士活到108岁,他死于冲浪事故)。你仍然可以购买这2段“诺沃克”机约2000美元,这是一个每个高昂价格。和大部分的榨汁机,你会发现销售还没有进化之后,和大多数的榨汁机,你会发现销售还没有进化之后,这让我们称之为离心式榨汁机，.离心式榨汁机工作通过使用平刀片快速旋转过滤器的底部。削减生产是扔的过滤器。由于受离心作用力，果汁然后穿过小孔通过过滤器流出，它的内在设计包括: 过滤器很大并且很难清洗干净。 切割刀片的清洗有一定的危险性。 过程包含大量氧化,因此会有一些垂死和棕色的汁。 有很多令人不愉快感到不舒服的泡沫。 没有草药和芽草之类的所以绿叶蔬菜是不可能的。 这些榨汁机可以严重的损害你的听力,不会受欢迎的，因为连栋房屋或公寓有噪音,没有人会睡好觉。 最后,设计离心式榨汁机，里面是不同于树木的切削刀。它们转速高达10000 r/min,旋转产生的摩擦对职业是不好的。当马达早在持续的抵抗之下10000 r/min,也不是一件容易的事，你可以花费在离心式榨汁机从30美元到100.美元不等,所以你支付什么呢?嗯,事实上,大多数品牌和审美设计.然而最便宜的机器肯定是周心,不会最后你长,经验和反馈告诉我们,更昂贵的机器不一定会长期工作下去，.事实上,如果大家都买了榨汁机，并且每天都在使用他们的机器，我们认为几乎每个机器日常使用的市场将被取消,因为每天用法实际上所有机器无法在他们的第一年之内，让单独在保单之内。本指南已经写的几个人的累积经验,跨越4年多。 对我们来说这是一个大胆的声明是榨汁机是提供保修的。大多数人我们说话,燃尽之前机器从来没有把它回来。我们生活在这样一个社会可悲的是,但它制造的大。社会的另一个事实是我们中有多少人新项目的橱柜,仅次于最可能的新项目的橱柜,仅次于乔治福尔曼风格烤架。我们相信这是由于上述缺点的这种风格的大街离心是迄今为止最购买的一种，这榨汁机处理整个生产制造过程，.整个苹果,芹菜的整个头，性能并不是最好的。一位健康食品作者告诉我们它的伟大在于能够把一整头的芹菜榨好，虽然最终,这个功能是方便,但是这个过程仍然破坏果汁,您仍然需要清理每一个玻璃以后被生产作为过滤器障碍物更加迅速。 接下来,我们都知道三角皮带传动的重要性。三角皮带传动广泛应用于各种各样的机器,所以理解和知道如何设计很试验台上三角皮带激励等三角皮带和滑轮是两个最重要的部分三角皮带驱动,中心距,滑轮的直径和滑轮直径是最基本的参数三角皮带传动三角皮带驱动。驱动皮带轮和动力输出轮,我们设计的直径比速度的基础。 三角皮带传动驱动皮带轮和动力输出皮带轮和无休止的三角皮带绕着两个滑轮。这个三角皮带驱动器配有扭矩测量装置在rpm传感器分配给驱动皮带轮和动力输出皮带轮,不断检测轮,两个传感器与电子控制哪些，决定之间的传动比传动和动力输出装置检测到滑轮,校准设备,这将一组齿轮速比与定义扭矩与电子控制,和电子控制与电子评估者。 本发明涉及提供一个三角皮带驱动,可以确定现有扭矩在不同驱动同一负载通过简单的手段和最优转矩现有在不同驱动同一负载以最优的方式,通过简单的手段和作为的运行部分的函数，v带传动,驱动轮,动力输出装置和三角皮带,控制并调整它。 三角皮带驱动按照发明配有扭矩测量装置,采用三角皮带在v形带沟槽的深度渗透的动力和动力输出装置滑轮,因此，通常被认为是滑移和没有考虑在内,从而造成的可变传动比以及这个齿轮比率相比,这些不断变化的函数驱动皮带轮上的负载,与预定的力矩电子设备,评估这对扭矩的变化差异获得的方式,导致实际转矩分别。 通过这可以在一个简单的和确定的方式和调整扭矩;同时检测并立即解决发展中问题,过载,磨损等的各种机器和设备驱动,如农业机械、工业机械和l相似，.不同的旋转直径带是由这些不同的渗透深度的三角皮带,正因为如此,两个滑轮.T或齿轮的不同转速比的两个滑轮是通过改变这措施.为了弥补这一行动,或改变传动比通过传感器,根据负载驱动皮带轮和他穿透深度的滑轮V带轮，滑轮不断发现通过滑轮的v带.不断发现通过传感器,和这些数据集中到电子设备.由此形成一个传动比。 空载条件或知道他三角皮带驱动负载校准标定装置的执行将RPM或传动比分配给其他一组上，述描述的具体化将因此完全揭示发明的一般性质,其他人可以通过运用现有知识,容易修改和/或调整等各种应用程序并且没有离开通用概念和它的具体体现,因此,适应和修改等,目的是应该理解的意义和范围内对应披露的化身,是理解词组或术语使用本是为目的的描述,而不是限制。 理解上述理论的目的是设计v形带激励等总体设计要求是得到最好的两个滑轮之间的中心距离. .当然,设计师有几个知道条件他/她开始设计之前,如驱动轮的转速、传动皮带轮之间的传动比和动力机械故障轮(或动力输出轮),电力传输和三角皮带的工作环境激励等设计的最终目的是使三角皮带传动的最小规模的会议,所有的工作需求的基础。 众所周知,三角皮带是最重要的三角皮带传动的一部分。然而重要理解三角皮带的设计和选择,人造丝和橡胶v形带广泛用于电力的传动.v带是有两个系列:标准三角皮带和高容量三角皮带,皮带可以使用较短的中心距离。三角皮带的优点之一是成本低,和输出功率高，可能增加了操作几个v带,身边的皮带驱动应该以同样的速度伸展为了保持负载同样分给them.When皮带断裂,通常必须被替代。开车可能倾向前或在任何角度的一边的下边.另外的优势是,它包括皮带槽角，通常从34-38的带槽的广泛作用，使机器大量增加牵引力并且由传送带传递。 而另一个重要部分三角皮带驱动轮,它可能用广泛应用在是铸铁、钢板或模铸金属灰色铸铁这些材料，当三角皮带的速度不超过25米/秒,我们应该采用HT150滑轮的材料,当速度是25到45米/秒之间,然后我们可以采用球墨铸铁,铸钢、锻钢,我们也可以焊接穿孔钢板作为滑轮，当需要的力不是很大时,滑轮也可以用铸铝或其他材料制作.皮带轮由轮缘,网络和轮中心构成.滑轮是一个市场,允许调整螺杆的宽度的有效直径滑轮是不同的,和温和的变化速度比通常有关,小皮带轮传动皮带轮,和大用作动力输出装置滑轮。 在我们理解常用的v型皮带传动的结构,我们应该分析三角皮带的力量,三角皮带的分析更重要,主力拉力和压力,和压力包括拉伸应力、弯曲应力和离心压力设计必须使拉力和压力不超过固定值以避免滑动,我们也应该使发射功率,三角皮带的张力和速度必须满足这一条件,三角皮带有足够的抗疲劳强度和一个明确的允许值。 接下来,我们应该知道轴、联轴器和滚动接触轴承。 几乎所有机器包含轴轴最常见的形状是圆形截面可以是实心或空心(空心轴可能导致重量储蓄).通常轴有时被用作在螺丝刀叶片,套筒扳手和控制旋钮茎。 轴必须有足够的抗扭强度传输扭矩和压力过大。它也足够扭力tiff,安装组件不偏离足够硬,一个安装组件不过分偏离原来的角位置相对于第二个组件安装在同一个轴上总体而言,扭转角度轴的长度不应超过或者等于20mm。 轴安装本质通过齿轮等设备和传输功率,滑动,凸轮和离合器这些设备介绍部队试图弯轴;因此,轴必须足够严格,防止超载的发生.在设备内部,轴的弯曲挠度之间的长度不应超过0.01英寸.满足轴承支持。 此外,轴必须能够承受弯曲和扭矩的组合作用，所以，必须考虑扭转和弯矩的当量载荷.，因为扭矩和弯矩会产生变应力，在许用应力中也应该有一个考虑疲劳现象的安全系数。 通常轴直径小于3英寸，材料可采用含碳量约为0.4%的冷轧钢,直径在3至5英寸大的，则采用锻造毛坯，。当直径大于5英寸时，则采用锻造毛坯，然后机械加工到所要求的尺寸。轻载时，广泛采用塑料轴。由于塑料是电的不是导体，在电器中用它做轴比较安全。 齿轮和皮带轮等零件通过键连接在轴上。在对键及轴上与之相应的键槽进行设计时，必须进行认真的计算。例如,应力集中发生在轴键槽,由于键槽存在使轴的横截面面积间隙，会料被进一步削弱了轴的强度。 如果轴以速度转动，,将会发生强烈的振动，可能会毁坏整台机器。,知道这些临界速度的大小是很重要的，这样就可以避免它的发生，一般凭经验来说，工作速度和临界转速之间的应该至少相差20%。 轴设计的另一个重要方面是轴与轴之间的直接联接方法，这是有刚性或者弹性联轴器来实现的。 联轴器是用来把两相邻的轴端联接起来的装置,在机械结构中，联轴器被用来实现两根转轴之间的半永久联接。在机器的正常的使用期间内，这种联轴器一般不必拆开，在这种意义上，可以说联轴器的联接是永久性的。但在紧急情况下，或者需要更换已经磨损的零件时，可以先把联轴器拆开，然后再连接上。 有几种类型的轴联轴器,其特征取决于它们的用途，如果制造工厂或船舶螺旋桨需要一根特别长的轴，可以采用分段的方式将其制造出来，然后采用刚性联轴器将各段联接起来。一种常用的联轴器是由两个配对的法兰组成，这两个法兰盘借助靠键传动的轴套联接到相邻两节轴的两端，然后用螺栓穿过法兰联接起来形成刚性接头。相互联接的两根轴通常是靠法兰面的槽口来对准的, 在把属于不同的设备（例如一个电动机和一个变速箱）的联联接起来的时候，要把这些轴精确地对准是比较困难的，此时可以采用弹性联轴器。这种联轴器联接的方式可以吧由于被联接的轴线不重合所造成的有害影响减少到最低程度。弹性联轴器也允许被联接的轴在它们各自的载荷系统作用下产生偏斜或者在轴线方向自由移动而不至于相互干扰。弹性联轴器也可以用来减轻一根轴传动另一根轴上的冲击载荷和振动的强度。 几乎所有轴都装有滚动轴承。对于球轴承和滚子轴承，一个机器设计员应该考虑下面五个方面：:(a)寿命与负载的关系;(b)刚度、也就是在荷载下的变形量;(c)摩擦:(d)磨损;(e)噪音。对于中等负载和转速选择一个标准的轴承，通常都可以抱着其令人满意的工作性能。当载荷较大时，轴承变得重要起来。在转速高的场合需要有专门的冷却装置，而这啃会增加摩擦阻力。磨损主要由于污染物的进入引起的，必须选用密封装置以防止周围环境的不良影响。 因为大批量生产这种方式决定了球轴承和滚子轴承不但质量高，而且价格低，因而机器设计人员的任务是选择而不是设计轴承。滚动接触轴承通常是采用硬度大约900HV、整体淬火的刚来制造的。但在许多机构上不使用专门的套圈，而将相互作用的表面淬硬到大约600HV。滚动轴承由于在工作中会产生高的应力，其主要失效形式是金属疲劳，这一点并不奇怪，目前正在进行大量的工作以求改进这种轴承的可靠性。通常设计轴承中将会有90%的轴承具有超过一百万转的寿命。 不承受责任的事实基本设计球和滚子轴承的轴承制造商,机器设计者必须从正确的升值的义务由轴承,不仅要考虑轴承选择而且还要考虑轴承的正确安装条件。轴承的配合比赛在轴或到住房是至关重要的,因为他们的结合影响轴承的内部间隙以及保存所需的干扰程度可以引起严重的麻烦担忧，经常位于轴向内部竞赛对接肩膀。此时,半径是重要为避免应力集中和球比赛提供了提供了一个半径或倒角允许空间。 设计生活不是决定性的因素,通常以确定最大载荷下轴承将转移的数量意味着可以应用于轴承的负荷,这是固定的或轻微的旋转运动,而不会影响它的运行品质随后转动motion.This已经由实践经验时的负载应用到轴承导致的总变形滚动体和滚道接触在任何时候不超过0.01%的滚动体直径.这相当于直径25mm的求产生0.0025mm的永久变形。 只有将轴承与周围环境适当的隔开，许多轴才能成功的实现它们的作用,在某些情况下，必须保护环境，使其不受润滑剂和轴承便面磨损生产物的污染，轴承设计的一个重要组成部分是使密封装置起到应有作用。此外，对摩擦学研究员来说，为了任何目的而应用于运动零部件上的密封装置都是他们感兴趣的。因为密封装置是轴承系统部分，只有根据适当轴承理论才能设计出令人满意的封密装置。虽然它们很重要，与轴承其他方面的研究工作相比，到目前为止在密封装置的研究方面所作出的工作相比，到目前为止在密封装置的研究方面所做出的工作还是比较少的。在最后,我们将介绍减速器。 减速器是一个动态的交流机构,利用齿轮的速度转换器,减速电机转速的旋转数,和有更大的扭矩机构.减速器的作用:(1) 同一时间，速度提高输出扭矩,输出转矩比由减速电机输出,但要注意超过额减速的同时降低了负载的惯量，惯量的减少为减速比的平方。大家可以看一下一般的电机都有一个惯量数值。(2) 定扭矩减速器。 通用斜齿轮减速器减速机(包括平行轴斜齿轮减速机,蜗轮减速机、斜齿轮减速机等。)行星齿轮减速机、摆线减速机、蜗轮减速机、行星摩擦无级变速机械机器。 第一,国内许多由齿轮传动减速器,蜗杆传动为主,但功率和负载比通常很小,或者速度比大而机械效率过低的问题，另外,材料的质量和技术水平也有很多弱点,大规模的减速齿轮的问题特别突出，寿命不是很长，国内使用大型减速齿轮(约50 kw),许多从国外(例如区别,德国等等)进口的60年代开始几齿减速机等等,不同传播,摆线销齿轮传动,泛音传输生产具有传动比大,体积小,机械效率高等优点。但它传播理论限制,不能传输过大的功率，功率一般都必须小于40千瓦,因为在传播理论上,技术水平和材料质量方面没有突破,因此,还不能从根本上解决传动功率大,传动比大,体积小,重量轻,机械效率高等这些要求。90年代的初期,国内出现三环（齿轮）的减速器，是一种齿轮传动减速装置,可以实现大传动比,传动负载能力也比较大。它体积和重量都是轻于定轴齿轮减速器,结构简单,效率也高因为这个减速齿轮三轴平行结构简单,因此造成功率/体积比仍很小，其输入轴和输出轴不在同一轴线上，这个在使用上没有许多不便，北京理工大学研制成功的内平动齿轮减速器，不仅具有三环减速器的优点，还有着大的功率/重量比值，以及输入轴和输出轴在同一轴线上的优点，处于国内领先地位，国内有少数高等学校和厂矿企业对齿轮传动中的某些原理做些研究工作，发表过一些研究论文，在利用摆线齿轮作平动减速器开展了一些工作。（2） 稳定运动减速器齿轮的工作原理简介、稳定运动齿轮减速机是指在一对齿轮减速器传动中，齿轮在平动发生器的驱动下作平面平行运动，通过齿廓间的啮合，驱动另一个齿轮作定,通过之间的齿廓啮合,启动另一个牙齿轮作定轴减速转动，实现减速传动的作用。平动发生器可采用平行四边形机构，或者正旋机构或十字滑块机构。平动发生器可以是虚拟的采用平行四边形机构，也可以采用实体的平行四边形机构。有实用价值的平动齿轮机构为啮合齿轮机构，因此又可分为内齿轮并做减速转动输出。该机构也称三环减速器。由于内齿轮传动，两曲柄中心能设置在外齿轮的齿圈内部，大大减少了机构整体尺寸。由于外齿轮作平动，两曲柄中心能设置在外齿轮的齿圈内部，大大减少了机构整体尺寸。由于内齿轮机构传动效率高、体积小、输入输出同轴线，故有广泛的应用前景。（3） 该项目技术特点和关键性功能的新的稳定的“动作”减速机齿轮和国内外有减速机齿轮相比,具有以下特点:(1)传动比范围大,自I= 10,起可能达到最达的几千I，若制造大速传动比的减速器,则显示了这种齿轮减速器的优点。(2)传动功率范围大，并可与电动机连接一体制造。(3)结构简单,体积小,重量是轻，比,现有的机齿轮减速器减少1/3左右。(4)机械效率很高。(5)此减速器输入轴和输出轴在同一的轴线上。因缺少数据,表中所列的各减速器的功率/重量比是最优越的。【1】、吉川,“分析和控制冗余机器人的“机械技术研究:第一个国际研讨会(m布雷迪和r .保罗eds)(麻省理工学院出版社、剑桥、质量)(1984)439 - 439页。【2】、克莱恩,“动冗余机械手避障在动态变化的环境中“。机器人研究1、3号109 - 117(1985)。列日瓦“自动监控的配置和多体的行为机制”IEEE反式。在系统中,人,Cybern。SMC-7,12号,868 - 871(1977)。3Chirikjian和J.W.布尔迪克“避障算法hyper-redundant操纵者，机械设计及其自动化,辛辛那提(1990年5月)第625 - 631页。【3J】.K.索尔兹伯里,J.J.克雷格的手:力控制和运动学问题“Int。1。机械设计技术研究1、第一4-17(1982)。【4】Dubey r和J.Y.S. Luh,“机械设备控制与自动化,罗利(1987年3月),页1066 - 1072。【5】、7W.K. K.W. Jeong、钟、y . Youm“发展POSTECH 7自由度直接驱动设计”3日ISRAM Conf . .温哥华(7月。1990)页577 - 582。附录二： The Honest Guide to Choosing a Juicer In the 1930s a cap called Dr Norman Walker invented a juicer which firstly grated and cut produce . The resulting mass was then to be put into a linen bag and placed under a hydraulic press, directing juice drown a spout.(Dr Walker lived to 108 years of age, he died in a surfing accident). You can still purchase this 2-stage “Norwalk” machine for around $2000, which is a every prohibitive price indeed. And most of the juicer you will find on sale havent evolved much since then,And most of the juicer you will find on sale havent evolved much since then,which brings us to called it Centrifugal juicers.Centrifual juicers work by using a flat cutting blade on the bottom of a rapidly spinning strainer. Cut produce is flung out over the sides of the strainer . Due to the cantrifugal force, juice then passes through tiny holes in the strainer.Features intrinsic this design include: f the two pulleys.The RPM or gear ratio of the two pulleys is changed by means of this action.To compensate for this action,the RPM or gear ratio is changed by means of the rpm sensor,depending on the load on the drive pulley and he penetration depth into pulleys of the v-belt.The rpm of The strainers are huge and a pain to clean . The cutting blades are tricky to clean and some are particularly dangerous to handle. The process incorporate mass oxidization and therefore a dying and brown juice. There is a lot of unpleasant forth . Leafy green vegetables are impossible,so no herb and no wheatgrass pulp in the juice. These juicers can seriously damage your hearing, and wont be popular in a terraced house or flat, or if anyone is still in bed. Ultimately, the technology inside a centrifugal juicer is not unlike that of a tree cutter. Theyre spinning at up to 10000rpm.The resulting frictional heat is not good. for your juice.Neither is 10000rpm an easy task for a motor when under constant resistance,The amount you can spend on centrifugal juicer varies from$30 to over $100.so what are you paying for?Well ,in truth, mostly brand name and aesthetic design.While the cheapest of machines are certainly week hearted and not going to last you long ,experience and feedback tells us that more expensive machines dont necessary last any longer.In fact ,if everyone who bought a juicer used their machine every day we think nearly every machine on the market would be withdrawn because with daily usage virtually all machines would fail within their year,let alone within warranty. This guide has been written as a result of the cumulative experience of several of several people,spanning over 4 years and many juices. And thats a brave statement for us to make but far braver is the warranty provided with juicer. Most people we speak to that have burnt out previous machines never even took it back. We live in a throw away society sadly, but its great for manufactures . Another fact of society is how many of us new item to be left in the cupboard , second only to the most likely new item to be left in the cupboard, second only to the George Foreman style grills. We believe this is because of the above drawbacks of this style of juicer-as the high street centrifugal is by far the most purchased type of this juicer-as the high street centrifugal is by far the most purchased type of juicer in the UK.Centrifugal juicers that handle whole produce.What a feature,hole apples,whole heads of celery.Having said that,impatience isnt the highest virtue.One health food author tells us “Its great being able able to put in a whole head of celery, but the keeps burning out and I have to take it to the shop”.Ultimately, this feature is one of convenience,but the process still destroys the juice,and you still have to clean up after every glass produced as the strainer clog seven more rapidly. Next ,we all know the importance of the V-belt Drive. The v-belt drive are widely used in all kinds of machines,so to understand and know how to design it is very necessary.The v-belt drive.The v-belt and the pulley are two most important parts of v-belt drive,the center distance,the diameter of the pulleys and the rpm of the pulleys are the most essential parameters of the v-belt drive. The v-belt drive has a drive pulley and a power take-off pulley,we design their diameters in the basis of speed ratio. The v-belt drive has a drive pulley and a power take-off pulley and endless v-belt rotating around both pulleys. This v-belt drive is equipped with a torque measuring device in that an rpm sensor is assigned to both the drive pulley and the power take-off pulley,which continuously detects the pulley rpm,the two rpm sensor are connected with an electronic control which determines the gear ratio between the drive and the power take-off pulleys from the detected rpm,a calibration device,which associates a set gear ratio with a define torque is connected with the electronic control, and the electronic control is connect with an electronic evaluator. The invention relates to the provision of a v-belt drive,where it is possible to determine the torque existing at different drive loads by simple means and in an optimal the torque existing at different drive loads by simple means and in an optimal manner,as a function of the coorperating parts of the v -belt drive,drive pulley, power take-off and v-belt,and to control and adjust it in his way. The v-belt drive in accordance with the invention is equipped with a torque measuring device , which uses the depth of penetration of v-belt in the v-belt grooves of the drive and power take-off pulleys ,which beretofore often had been considered to be slippage and had not been taken into account,as well as the variable gear ratio caused thereby and compares this gear ratio,which continuously changes as a function of the load on the drive pulley,in an electronic device with a predetermined torque, evaluates this differences obtained in manner for the changing torques,which results in the respectively actual torque. By means of this it is possible in a simple and assured manner and adjust the torque;at the same time detect and immediately remedy developing troubles,overloads,wear and the like in connection with the various machines and devices to be powered,such as agricultural machinery,industrial machinery and the like.Differing rotational diameter of the belt are caused by these differing penetration depths of the v-belt and,because of that ,different rpm oboth pulleys is continuously detected by means of the v-belt.The rpm of both pulleys is continuously detected by means of the rpm sensors,and these numbers are centered into the electronic device.which forms a RPM gear ratio therefrom. In the no-load condition or with a know load of he v-belt drive a calibration is performed in the calibration device by assigning the RPM or gear ratio to a set torque.The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can , by applying current knowledge,readily modify and /or adapt for various applications such specific embodiments without departing from the generic concept,and ,therefore,such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments .It is to be understood that phraseology or terminology employed herein is for the purpose of description and not limitation. The purpose of understanding the above theory is to design the v-belt drive.The total design requirement is to get the best distance between the centres of the two pulleys. Of course,the designer has a few know conditions before he/she start the design, such as the rpm of the drive pulley,the gear ratio between the drive pulley and the power take -off pulley(or the rpm of the power take-off the pulley),the power to be transmitted and the work circumstances of the v-belt drive.The final purpose of the design is to make the v-belt drive have the least size in the basis of meeting to all the work requirements. As known to all ,the v-belt is the of the most important part of the v-belt drive. Scompreis important to comprehend the construction of the v-belt and to choose it .the rayon and rubber v-belt are widely used for power transmission.Such belts are made in two series:the standard v-belt are and the high capacity v-belt .The belt can be used with short center distances and are made endless. One of the virtues of the v-belt is that the cost low,and power output may be increased by operating several belts side by side.All the belts in the drive should stretch at the same rate in order to keep the load equally divided among them.When one of the belt breaks, the group must usually be replaced. The drive may be inclind at any angle with tight side either top or bottom.Another advantage is that the include angle for the belt groove is usually from 34-38,the widing action of the belt in the groove gives a large increase in the tractive force developed by the belt. Another important part of the v-belt drive is the pulley,it may be made of cast iron,sheet steel or die cast metal ,gray cast-iron is widely used of all these materials.When the speed of the v-belt is not more than 25m/s,we should adopt HT150 as the materials of the pulleys;When the speed is between 25 to 45m/s,then we can employ nodular cast iron,cast steel or forged steel,we also can weld the punched steel plate to use as the pulleys.When the power delivered is not very much ,the pulleys also can be made in cast aluminum or plastic.The pulley is composed by wheel flange,web and wheel nave.Pulley are an the market that permit an adjustment in the width of the groove.The effective diameter of the pulley is varied,and the moderate changes in the speed ratio can be secured.Usually, the small pulley is the drive pulley ,and the large one is used as the power take-off pulley. After we understand the usual structure of the v belt drive ,we should analyse the force of the v-belt,the analysis of the v-belt is more important,the main force are pulling force and stress,and the stress include pulling stress,bending stress and centrifugal stress.The designer must make the pulling force and the stress are not more than the permanent value.In order to avoid the slip slide,we also should make the transmitted power,the pulling force and the speed of v-belt must be satisfied ,it is to say.the v-belt has enough fatigue resistance and a definite lifetime. Next,we should know the shafts、couplings and rolling contact bearings. Virtually all machines contain shafts.The most common shape for shafts is circular and the cross section can be either solid or hollow(hollow shafts can result in weight savings).Rectangular shafts are sometimes used as in screwdriver blades,socket wrenches and control knob stems. A shafts must have adequate torsional strength to transmit torque and not be overstressed. It also be torsionally tiff enough so that one mounted component does not deviate stiff enough so that one mounted component doesnt deviate excessively from its original angular position relative to a second component mounted on the same shaft.Generally speaking,the angle of twist should not exceed one degree in a shaft length equal to 20 diameters. Shafts are mounted inbearings and transmit power through such devices as gears,pullerys,cams and clutches.These devices introduce forces which attempt to bend the shaft;hence,the shafts must be rigid enough to prevent overloading of the supporting bearings.In general,the bending deflection of a shaft should not exceed 0.01 in .perft to length between bearing supports. In addition,the shafts must be able to sustain a combination of bending and torsional loads.Thus an equivalent load must be considered which takes into account both torsion and bending.Also, the allowable stress must contain a factor of safety which includes fatigue,sine torsional and bending stress reversal occur. For diameters less than 3 in the usual shaft material is cold-rolled ateel containing about 0.4percent carbon.Shafts are either cold-rolled or forged in sizes from 3 in . To 5 in,shafts are forged and machined to size.Plastic shafts are widely used for light load applications.One advantage of using plastic is safety in electrical applications,since plastic is a poor conductor of electricity. Component such as gear and pullerys are mounted on shafts by means of key.The design of the key and corresponding key way in the shaft must be quickly evaluated. For example,stress concentrations occur in shafts due to keyways ,and the material removed to from the keyway further weakens the shaft. If shafts are run at cirtical speeds,severe,sever vibrations can occur which can seriously damage a machine.It is important to know the magnitude of these critical speeds so that they can be avoided,As a general rules of thumb,the difference between the operating speed and the critical speed should be at least 20 percent. Another important aspect of shafts design is the method of directly connecting one shaft to another.This is accomplished by devices such as rigid and flexible couplings. A coupling is a device for connecting the eds of adjacent shafts.In machine construction,oupling are used to effect a semipermanent connection between adjacent rotating shafts.The connection is permanent in the sense that it is not meant to be broken during the useful life of the machine,but it can be broken and restored in an emergency or when worn parts are replaced. There are several types of shaft couplings,their characteristics depend on the purpose for which they are used.If an exceptionally long shaft is required in a manufacturing plant or a propeller shaft on a ship,it is made in sections that are coupled together with rigid couplings.A common type of rigid coupling consists of two mating radial flanges(disks）that are attached by key-driven hubs to the eds of adjacent shaft sections and bolted together through the flanges to form a rigid connection.Alignment of the connected shafts is usually effected by means of a rabbet joint on the face of the flanges. In the connecting shafts belongs to separate devices (such as an electric motor and a gearbox),precise aligning of the shafts is difficult and a flexible coupling is used.This coupling connects the shafts in such a way s to minimize the harmful effects of shaft misalignment.Flexible couplings also permit the shafts to deflect under their separate systems of with one another.Flexible couplings can also serve to reduce the intensity of shock loads and vibrations transmitted from one shaft to another. Virtually all shafts contain rolling contact bearing.The concern of a machine designer with ball and roller bearings is five fold as follows:(a)life in relation to load;(b)stiffness,deflections under load;(c)friction:(d)wear;(e)noise/For moderate loads and speeds the correct selection of a standard bearing on the basis of load rating will usually secure satisfactory performance.The deflection of the bearing elements will become important where loads are high,although this is usually of less magnitude than that of the shafts or other components associated with the bearing.Where speeds are high special cooling arrangements become necessary which may increase frictional drag.Wear is primarily associated with the introduction of contaminants,and sealing arrangement must be chosen with regard the hostility of the environment. Because the high quality and low price of ball and roller bearings depends on quantity production,the task of the machine designer become one of selection rather than design.Rolling-contact bearings are generally made with ateel which is through-hardened to about 900HV,although in many mechanisms special races are not provided and the interacting surfaces are hardened to about 600HV.It is not surprising that,owing to metal fatigue,and a good deal of work is currently.Design can be based on accepted values of life and it is general practice in the bearing industry to define the load capacity of the bearing as that value below which 90 percent of a batch will exceed a lift of one million revolution. Not withstanding the fact that responsibility for the basic design of ball and roller bearings rests with the bearing manufacturer,the machine designer must from a correct appreciation of the duty to be performed by the bearing and be concerned not only with bearing selection but with the conditions for correct installation. The fit of the bearing races onto the shaft or onto the housing is of critical importance because of their combined effect on the internal clearance of the bearing as well as preserving the desired degree of interference can induce serious trouble from fretting corrosion.The inner race is frequently located axially by abutting against a shoulder. A radius at this point is essential for the avoidance of stress concentration and ball races are provides with provides with a radius or chamfer to allow space for this. Where life is not the determining factor in design,it is usual to determine maximum loading by the amount to which a bearing will deflect under mean the load that can be applied to bearing,which is either stationary or subject to slight swiveling motions,without impairing its running qualities for subsequent rotational motion.This has been determined by practical experience as the load which when applied to bearing results in a total deformation of the rolling element and raceway at any point of contact not exceeding 0.01 percent of the rolling-element diameter.This would correspond to permanent deformation of 0.0025mm for a ball 25 mm in diameter. The successful functioning of many bearing depends upon providing them with adequate protection against their environment,and in some circumstances the enviroration of the bearing surfaces.Achievement of the correct functioning of seal is an essential part of design. Moreover , seals which are applied to moving parts for any purpose are of interest to tribologists because they are components of bearing systems and can only be designed satisfactorily on the basis of the appropriate bearing theory.Not withstanding their importance,the amount of research effort that has been devoted to the understanding of the understanding of the behavior of seal has been small when compared with that devoted to other aspects of bearing technology. At the last ,we will introduce the reducer. Reducer is a dynamic communication agencies,the use of gear speed converters,motor rotational speed reducer to be the Rotary to be few,and have greater torque institutions.The reducer role: velocity at the sametime increase the output torque,output torque ratio by motor output by slowdown,but the attention should be paid to exceed the rated torque reducer. The speed at the same time reduce the inertia load,the inertia of deceleration than reduced to the square.We can look at the General Motors has a value of inertial. General helical gear reducer has reducer (including parallel shaft helical gear reducer,a worm reducer,bevel gear reducer an so on.)Planetary gear reducer,Cycloid reducer,a worm reducer, a planetary friction CVT mechanical machines. First, the domestic reduction gear many by the gear drive,the worm drive primarily,but has the power and the load ratio generally is small,or velocity ratio great and mechanical efficiency excessively low question.Moreover, in the material quality and the technological level also has many weakness,the large-scale reduction gear question is specially more prominent,the service life is not long.The domestic use large-scale reduction gear (about 50kw),many from overseas(for example Demark,Germany and so on)imports The 60 s start few tooth reduction gears and so on,difference transmission,cycloid pin gear transmission,overtone transmission which produces has velocity ratio to be big,volume small,mechanical efficiency higher merit? But its transmission theory limit,can not transmit the oversized power,the power all must be smaller than generally 40kw,because in the transmission theoretically,the technological level and the material quality aspect has not broken through,therefore,has not been able fundamentally to solve the transmission power in a big way ,the velocity ratio big,the volume small,the weight light,mechanical efficiency higher these requests basically.The 90s initial period,the home appears three links the reduction gear is one kind of outsides stable motion gear drive reduction gear,it may realize the great velocity ratio,transmission load ability is also big.Its volume and the weight are all lighter than the dead axle speed reducer gear,the structure is simple,the efficiency is also high.Because this reduction gear three axle parallel structure is simple,therefore caused the power /volume the ratio is still small.Also its input axis and the output shaft on the identical spool thread,this do not have in the use many inconveniently.Not omly Beijing Institute of Technology develops develops in succssful”stable motion speed reducer gear “to have outside three link reduction gear merit,but also has the big power?weight (or volume)the ratio,as well as the input axis and the output shaft on identical spool thread merit,is at the domestic leading position.The home has the minority college and the factory and mining enterprise does the research work to in stable motion gear drive certain principles,has published some search paper,in has done some work using the cycloidal tooth crop rotation stable motion reduction gear. Second.the stable motion speed reducer gear principle of work synopsis,the stable motion speed reducer gear is refers to in