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自行车变速器设计（桂理工）,自行车,变速器,设计,理工
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本科毕业设计(论文)外文翻译（附外文原文） 学 院： 机械与控制工程学院 课题名称： 自行车变速设计 专业(方向)： 机械（模具） 班 级： 机械11-2班 学 生： 何更旺 指导教师： 刘电霆 日 期： 2015.3.10 译文：设计及制造轴传动的自行车M.Rama纳拉辛哈雷迪，助理，教授，科学与技术（svtm）的Vishveswaraiah爵士研究所附属于JNTU-A，Madanapalli，Chittoor（DIST），AP，印度。G.哈日普拉萨德1，2 S.Marurthi，R.Ganapathi3，M.Janardhan4，MPMadhu sudhan5。1,2,3,4,5（四年度B.Tech机械工程，科学与技术（svtm）的Vishveswaraiah爵士研究所附属于JNTU-A，Madanapalli，Chittoor（DIST），AP，印度。摘要：该项目开发为用户旋转两轮车用螺旋桨轴的后轮。通常在两轮车，链条和链轮方法被用于驱动后轮。但在该项目中，发动机连接在车辆的前部。发动机的轴与一个长棒相连。长棒的另一侧与一组锥齿轮相连。锥齿轮用于旋转90角的轴。车辆的后轮与锥齿轮（驱动）连接。因此，后轮旋转在垂直于发动机轴。因此，两轮车将向前迈进。根据发动机的运动方向，车轮将会向前移动或扭转。这避免了链条与链轮方法的使用。1 引言一轴传动是利用链条的驱动轴，而不是从踏板发射功率在引入一个多世纪以前以下图1-1轴驱动器显示的轮子安排一辆自行车，但大多是由链 - 取代由于齿轮驱动的自行车的范围可能与链轮和拨链器。近日，由于内齿轮技术的进步，也有少数的现代轴驱动的自行车已出台。轴驱动的自行车有一个大锥齿轮，其中传统的自行车将有其链环。这与啮合另一个伞齿轮安装在驱动轴这是在图1中示出。使用锥齿轮允许从踏板的驱动转矩的轴以通过90度转动。 图1-1自行车结构 驱动轴然后还有一个锥齿轮靠近后轮轮毂，其与斜齿轮相啮合的轮毂其中，后链轮将在一个常规的自行车，并抵消轴的第一驱动转矩变化。 1.1 使用传动轴即从踏板和传动产生的扭矩必须转移到后轮到车辆向前推并扭转。驱动轴必须提供功率的平滑，连续流至车轴。驱动轴和差速器用于传送这个扭矩。 图1-2传动轴的自行车1.2驱动轴的作用1.它必须从发送到脚踏板传递转矩。 2.操作时，有必要来传送由所述踏板开发最大的低档扭矩。3. 驱动轴还必须能够旋转由车辆所要求的非常快的速度的。4.驱动轴还必须通过传输，差分和车轴之间不断变化的角度进行操作。2 轴传动的发展史第一轴驱动器的周期似乎已独立发明于1890年在美国和英国。驱动轴扭矩是携带者;它们受到扭转和剪切应力，它代表了输入力和负荷之间的差。因此，他们需要强大到足以承受压力，不凭借轴的重量施加太大的额外的惯性。今天大多数的汽车用刚性驱动轴从变速器向车轮传递动力。一对短驱动轴的通常用于从中央差速器，变速器或transaxie给车轮发送功率。3 自行车的组件 图3-1 轴驱动自行车的部件3.1踏板自行车踏板是骑车人将他们的脚以推动自行车的自行车的一部分。它提供了骑车者的脚或鞋与曲柄使腿转底托架的主轴和推进自行车的轮子之间的连接。踏板通常由一个主轴该边线到曲柄和一个机构，在其上的搁脚板或附着的端部，也就是可以自由地相对于所述主轴上旋转的轴承。连接部分的曲柄旋转骑单车提供自行车动力;它由三个部分组成，如上图所示。3.2挡泥板弯曲的金属覆盖车轮的一部分，以保护骑车人从轮片飞溅的泥。3.3前刹机制刹车线压缩复位弹簧卡尺激活。它迫使一对侧壁刹车片停下自行车。3.4连接装置从该轮辐传动，在轮毂内部的轮的中心部分是球轴承，使在轴周围旋转。3.5锥齿轮一种齿轮的其中两个轮子一起工作在于不同的平面上，并有自己的牙齿切成直角的两个锥体，其顶点与点所在的轮的轴将满足重合的表面上。 图3-2锥齿轮3.6从动轴轴传动是使用链的驱动轴而不是从脚蹬到车轮传递动力的自行车。轴驱动器引入了一个多世纪以前，但大多采用链条驱动自行车取代因齿轮的范围可能与链轮和变速器。近日，由于内齿轮技术的进步，也有少数的现代轴驱动的自行车相继出现。3.7轴传动的优点1.具有高比模量和强度，2减少重量，3.由于重量减少，能量消耗将减少，4.具有高阻尼能力，因此它们产生更少的振动和噪音，5.具有良好的耐腐蚀性，6.扭矩容量比钢或铝轴更大，7.疲劳寿命比钢或铝轴更长，8. 旋转重锤传递更多可用功率更大。齿轮经常被安装在轴上并以90度分开，但也可以设计成其他角度，以正常工作。锥齿轮的节距表面是锥形。在齿轮的两个重要概念沥青面和俯仰角。一个齿轮的节面是虚无牙表面，你将不得不通过平均出各齿的峰和谷。一个普通的齿轮的节面是一个圆筒的形状。一个齿轮的倾斜角是俯仰面的面和axis.The最熟悉各种锥齿轮之间的角度具有小于90度的俯仰角，因此是圆锥状。这种类型的锥齿轮的被称为外部因为轮齿朝外。的啮合外部锥齿轮节距表面是同轴的齿轮轴;两个表面的顶点是在轴的轴的交叉点。4 方法的选择4.1选择锥齿轮 4.2选择传动轴 4.3配售锥齿轮 5 建设和工作轴也推动车辆前进。轴是在前端和后端之间的主连接，它执行的传送运动和推进前端。驱动轴的设计在图所示。 因此，通常传动轴和螺旋桨轴可互换使用。换句话说，驱动轴是纵向动力传递，在车辆中使用，其中所述踏板位于在人脚。驱动轴是由通用，等速或柔性接头连接一个或多个管状轴装配。管状件和节点的数量取决于两个轮子之间的距离。所涉及的工作是设计为合适的传动轴和更换链传动的平滑以从踏板动力传递给车轮，而不滑移。它只需要较少的维护。它具有成本效益。传动轴强度更并且也螺旋桨轴的直径较小。它吸收震动。因为推进器轴中心装有万向接头是柔性接头。它变成任何角位置。该轴的端部都配有锥齿轮，功率啮合的小锥齿轮经由传动轴和齿轮箱传递到后轮。与我们的轴传动的自行车，还有你的手或衣服没有更多的油脂;并没有更多的链和变速器的维护。5.2条件假设1.轴以绕其纵向轴线以恒定速度。2.轴具有均匀的，圆形的横截面。3.轴是完全平衡的，也就是说，在每一个横截面，所述质心与几何中心重合。4.所有阻尼和非线性效应被排除在外。5应力应变关系是线性的弹性和;因此，胡克定律适用于复合材料。6.流体相互作用忽略不计，即假定轴在真空中作用。7. 薄层薄且无外的平面负荷施加，它被认为是平面应力下作用。5.3扭矩传输作用与反作用我的朋友。如果一个人不转的踏板，然后他会站在它，所以最大扭矩= 0.008*16/2=0.128/2=0.064N*m模块（M）=0.008m惯性（I）= MR2的质量矩/2= 4 *0.0142=0.0039惯性（J）极矩=（DO4 - DI4）/32=（0.0284 - 0.0264）/32=（4.953X10-7）/32=1.54810-85.4轴的设计计算轴（DI）= 0.026m外径（D0） =0.028m轴长=0.335m齿数=16齿轮节距（P）= MT /2其中，自行车最大扭矩为T=（车手XG质量）L给定 ，L=踏板曲柄的“M”G长 = 9.81m/sec2（假设骑手的质量=60公斤）= 609.81 x0.335= 197.2N*m功率（P）=2NT/ 60=（2110 x197.2）/60=2271.5W剪应力（）=T/ J =（197.2）（7209）/1.54810-8 =9.181013 N/m4最大剪切应力（max）= TRO/ J=（197.2）（0.014）/（1.54810-8）=17.8310 7N弯矩（M）= EI/ R其中，E =杨氏模量I =惯性的R=瞬间半径（RO）M =（105 X0.0039）/0.014=29.25汇率扭曲= T / GJ=197.2/（36.75）（1.548*10-8）=3.46108剪应变=(扭曲率)=7209 X3.46 X108=2.491012= TL/ GJ=（197.2）（0.335）/（36.75）（1.54810-8）=66.06/（5.68X10-7）=1.163*109扭转是一个对象的扭转由于所施加的扭矩。它被表示在牛顿米（Nm的），在垂直于所述转矩轴的部分，在此部分所得到的剪切应力垂直于半径。为均匀的横截面的轴扭力是：T是施加的扭矩。T是最大剪应力的外表面JT= JZZ为同心圆形管r是旋转轴之间的距离是转矩被施加到或超过该对象的长度。 是扭曲的弧度的角度G是剪切模量或刚度的量（GPa）更常用的模量，ro外半径扭转（T）=JT.G/ L=（1.54810-8）（36.75）（1.163 X109）/0.335扭力（T）=1974.9 Nm偏转量（YMAX）= ML2/2EI=（29.25 0.3352）/（2105 0.0039）=4.008m，最大偏转量=T do / 2 / I=29.25 X0.014/0.0039=105 最大剪切应力（max）=（29.25 X0.014）/（1.54810-8）=26.4510 7Pa扭矩传递能力（T）由下式给出T = SS *（DO4 - DI4）/16（假设剪切强度（SS）=3601200MPa）T =360（0.0284 - 0.0264）0.028/16=3.12010-7 N*M张屈曲容量=(t*L2)/=(0.003*0.3352*0.003)/=3.70*10-4m6 结论首先该项目无法完成与驱动轴由于各种问题周围围了自行车，后来这是实现了两个成功运行伞齿轮在驱动轴的两端。所提出的工作的目的，以减少自行车人力（能量）的浪费骑马或任何机器，它采用驱动器轴;一般它是通过使用光来实现与伞重量传动轴齿轮两侧设计的更换链条传动。所提出的工作还涉及设计优化，即在将旋转运动转换与两个锥齿轮援助线性运动。相反的链传动一件传动轴后轮驱动的自行车已经优化设计和制造容易动力传输。以应用为目标的驱动轴最小重量轴这是进行约束，如扭矩传输，扭转屈曲能力，压力，应变等自行车的转矩传递容量传动轴已经被计算忽略，并考虑离心力的作用并且已经观察到，离心力将降低，转矩传递容量轴上的应力分布和最大在传动轴变形的功能的材料的堆叠。最佳材料层的堆叠可以被用作有效的工具，以减轻重量和压力演技在驱动轴上。驱动轴的设计是至关重要的，因为它是承受联合负荷。设计者两个选项设计驱动轴是否选择实心或空心轴。固体轴给出转矩的最大值传输,但由于增加的同时重轴，对于给定的重量，所述中空轴是更强，因为它具有更大的直径，由于重量轻和少弯矩从这项工作中所取得的成果是一个有用的逼近到的早期阶段帮助开发，节省了开发时间和帮助在决策过程优化设计。驱动轴曾担任替代一个链传动的自行车过去的一个世纪，从来没有变得非常流行故障排除，当检测到异常振动或噪音在驱动轴面积，该图可以被用来帮助诊断可能的原因。请记住，其它组分如车轮，轮胎，后桥和悬架也可以产生类似的条件。参考文献1 Rastogi, N. (2004). Design of composite drive shafts for automotive applications.Visteon Corporation, SAE technical paperseries.2 73332270 Design and Analysis of a Propeller Shaft of a Toyota Qualis by “SyedHasan”.3 A.M.Ummuhaani and Dr.P.Sadagopan “Design, Fabrication and Stress Analysis of a Composite Propeller Shaft, 2011-28-0013.4 Anup A. Bijagare, P.G. Mehar and V.N. Mujbaile “Design Optimization & Analysis of Drive Shaft”, Vol. 2 (6), 2012, 210-215.5 Rangaswamy, T.; Vijayrangan, S. (2005). Optimal sizing and stacking sequence of composite drive shafts. Materials science, Vol. 11 No 2., India. 6 Rastogi, N. (2004). Design of composite drive shafts for automotive applications. Visteon Corporation, SAE technical paper series. 7 R. P. Kumar Rompicharla1, Dr. K. Rambabu2 Sep-Oct. 2012 Design and Optimization of Drive Shaft with Composite Materials International Journal of Modern Engineering Research (IJMER)Vol.2,Issue.5,pp-3422-3428ISSN:2249-6645.International Journal of Emerging Engineering Research and Technology Volume 2, Issue 2, May 2014, PP 43-49 IJEERT 43 Design & Fabrication of Shaft Drive for Bicycle M.Rama Narasimha Reddy, Asst-Prof, Sir Vishveswaraiah Institute of Science &Technology(svtm),Affiliated to JNTU-A, Madanapalli, Chittoor (Dist), A.P., India G. Hari Prasad 1, S.Marurthi 2, R.Ganapathi 3, M.Janardhan4, M.P.Madhu sudhan5 1,2,3,4,5(IV Year B.Tech Mechanical Engineering , Sir Vishveswaraiah Institute of Science &Technology(svtm),Affiliated to JNTU-A, Madanapalli, Chittoor (Dist), A.P., India. Abstract: This project is developed for the users to rotate the back wheel of a two wheeler using propeller shaft. Usually in two wheelers, chain and sprocket method is used to drive the back wheel. But in this project, the Engine is connected at the front part of the vehicle. The shaft of the engine is connected with a long rod. The other side of the long rod is connected with a set of bevel gears. The bevel gears are used to rotate the shaft in 90 o angle. The back wheel of the vehicle is connected with the bevel gear(driven). Thus the back wheel is rotated in perpendicular to the engine shaft. Thus the two wheeler will move forward. According to the direction of motion of the engine, the wheel will be moved forward or reverse. This avoid the usage of chain and sprocket method 1. INTRODUCTION A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel arrangement displayed in the following fig 1. Shaft drives were introduced over a century ago, but were mostly supplanted by chain-driven bicycles due to the gear ranges possible with sprockets and derailleur. Recently, due to advancements in internal gear technology, a small number of modern shaft-driven bicycles have been introduced. Shaft-driven bikes have a large bevel gear where a conventional bike would have its chain ring. This meshes with another bevel gear mounted on the drive shaft which is shown in fig 1. Fig.1.1. Replacement of chain drive bicycle with driveshaft The use of bevel gears allows the axis of the drive torque from the pedals to be turned through 90 degrees. The drive shaft then has another bevel gear near the rear wheel hub which meshes with a bevel gear on the hub where the rear sprocket would be on a conventional bike, and canceling out the first drive torque change of axis. Fig2. Shaft drive for bicycle 1.1 Use of drive shaft The torque that is produced from the pedal and transmission must be transferred to the rear wheels to push the vehicle forward and reverse. The drive shaft must provide a smooth, uninterrupted flow of power to the axles. The drive shaft and differential are used to transfer this torque. 1.2 Functions of the Drive Shaft 1. First, it must transmit torque from the transmission to the foot pedal. 2. During the operation, it is necessary to transmit maximum low-gear torque developed by the pedal. 3. The drive shafts must also be capable of rotating at the very fast speeds required by the vehicle. M.Rama Narasimha Reddy etal. International Journal of Emerging Engineering Research and Technology 44 4. The drive shaft must also operate through constantly changing angles between the transmission, the differential and the axles. 2. LITERATURE REVIEW The first shaft drives for cycles appear to have been invented independently in 1890 in the United States and England. The Drive shafts are carriers of torque; they are subject to torsion and shear stress, which represents the difference between the input force and the load. They thus need to be strong enough to bear the stress, without imposing too great an additional inertia by virtue of the weight of the shaft. Most automobiles today use rigid driveshaft to deliver power from a transmission to the wheels. A pair of short driveshaft is commonly used to send power from a central differential, transmission, or transaxie to the wheels. 3. COMPONENTS OF BICYCLE Fig3.1. components of shaft driven bicycle 3.1 Paddle A bicycle pedal is the part of a bicycle that the rider pushes with their foot to propel the bicycle. It provides the connection between the cyclists foot or shoe and the crank allowing the leg to turn the bottom bracket spindle and propel the bicycles wheels. Pedals usually consist of a spindle that threads into the end of the crank and a body, on which the foot rests or is attached, that is free to rotate on bearings with respect to the spindle. Part attached to crank that cyclist rotate to provide the bicycle power; it consists of three segments as shown in figure 3.2 Fender Piece of curved metal covering a part of wheel to protect the cyclist from being splashed. 3.3 Front Brake Mechanism activated by brake cable compressing a calliper of return springs. It forces a pair of brake pads against the sidewalls to stop the bicycle. 3.4 Hub Centre part of the wheel from which spoke radiate, inside the hub are ball bearings enabling to rotate around in axle. 3.5 Bevel gear A kind of gear in which the two wheels working together lie in different planes and have their teeth cut at right angles to the surfaces of two cones whose apices coincide with the point where the axes of the wheels would meet. Fig3.2. Bevel Gear 3.6 Driven Shaft A shaft-driven bicycle is a bicycle that uses a drive shaft instead of a chain to transmit power from the pedals to the wheel. Shaft drives were introduced over a century ago, but were mostly supplanted by chain-driven bicycles due to the gear ranges possible with sprockets and derailleurs. Recently, due to advancements in internal gear technology, a small number of modern shaft-driven bicycles have been introduced. 3.7 Merits of Drive Shaft 1. They have high specific modulus and strength. 2. Reduced weight. 3. Due to the weight reduction, energy consumption will be reduced. 4. They have high damping capacity hence they produce less vibration and noise. 5. They have good corrosion resistance. 6. Greater torque capacity than steel or aluminum shaft. 7. Longer fatigue life than steel or aluminum shaft. 8. Lower rotating weight transmits more of available power. 3.8 Selection of Bevel Gear Bevel gears are gears where the axes of the two shafts intersect and the tooth-bearing faces of the gears themselves are conically shaped. Bevel Design & Fabrication of Shaft Drive for Bicycle International Journal of Emerging Engineering Research and Technology 45 gears are most often mounted on shafts that are 90 degrees apart, but can be designed to work at other angles as well. The pitch surface of bevel gears is a cone. Two important concepts in gearing are pitch surface and pitch angle. The pitch surface of a gear is the imaginary toothless surface that you would have by averaging out the peaks and valleys of the individual teeth. The pitch surface of an ordinary gear is the shape of a cylinder. The pitch angle of a gear is the angle between the face of the pitch surface and the axis.The most familiar kinds of bevel gears have pitch angles of less than 90 degrees and therefore are cone-shaped. This type of bevel gear is called external because the gear teeth point outward. The pitch surfaces of meshed external bevel gears are coaxial with the gear shafts; the apexes of the two surfaces are at the point of intersection of the shaft axes. 4. SELECTION OF METHODOLOGY 4.1 Selection of bevel gear 4.2 Selection of Drive shaft 4.3 Placing of bevel gear 4.4 Testing and correction 5. CONSTRUCTION AND WORKING PRINCIPLE Table4.2. Mechanical properties of Cast iron S.No Mech.Properties Symbol Units Cast Iron 1. Youngs Modulus E GPa 105.0 2. Shear Modulus G GPa 36.75 3. Poisson Ratio v - 0.23 4. Density Kg/m3 7209 5. Yield Strength Sy MPa 130 6. Shear Strength Ss MPa 169 The term Drive shaft is used to refer to a shaft, which is used for the transfer of motion from one point to another. Whereas the shafts, which propel is referred to as the propeller shafts. However the drive shaft of the automobile is also referred to as the propeller shaft because apart from transmitting the rotary motion from the front end to the rear end of the vehicle, these shafts also propel the vehicle forward. The shaft is the primary connection between the front and the rear end, which performs both the jobs of M.Rama Narasimha Reddy etal. International Journal of Emerging Engineering Research and Technology 46 transmitting the motion and propelling the front end. The design of drive shaft as shown in fig. Thus the terms Drive Shaft and Propeller Shafts are used interchangeably. In other words, a drive shaft is a longitudinal power transmitting, used in vehicle where the pedal is situated at the human feet. A drive shaft is an assembly of one or more tubular shafts connected by universal, constant velocity or flexible joints. The number of tubular pieces and joints depends on the distance between the two wheels. The job involved is the design for suitable propeller shaft and replacement of chain drive smoothly to transmit power from the pedal to the wheel without slip. It needs only a less maintenance. It is cost effective. Propeller shaft strength is more and also propeller shaft diameter is less. it absorbs the shock. Because the propeller shaft center is fitted with the universal joint is a flexible joint. It turns into any angular position. The both end of the shaft are fitted with the bevel pinion, the bevel pinion engaged with the crown and power is transmitted to the rear wheel through the propeller shaft and gear box. . With our shaft drive bikes, there is no more grease on your hands or your clothes; and no more chain and derailleur maintenance. 5.1 Specification of drive shaft The specifications of the composite drive shaft of an automotive transmission are same as that of the steel drive shaft for optimal design. The material properties of the steel (SM45C) are given in Table. The steel drive shaft should satisfy three design specifications such as torque transmission capability, buckling torque capability and bending natural frequency. 5.2 Design Assumptions 1. The shaft rotates at a constant speed about its longitudinal axis. 2. The shaft has a uniform, circular cross section. 3. The shaft is perfectly balanced, i.e., at every cross section, the mass center coincides with the Geometric center. 4. All damping and nonlinear effects are excluded. 5. The stress-strain relationship for composite material is linear & elastic; hence, Hookes law is Applicable for composite materials. 6. Acoustical fluid interactions are neglected, i.e., the shaft is assumed to be acting in a vacuum. 7. Since lamina is thin and no out-of-plane loads are applied, it is considered as under the plane Stress. 5.3 Transmission of Torque Action and reaction my friend. If a person does not turn the pedal then he will stand on it and so the maximum torque will = (body mass of the rider x g) x the length of the pedal lever. Remember to consider the gearing of the bike though. 5.4 Design Calculations Inner Diameter of shaft (di) = 0.026 m Outer Diameter of shaft (do) = 0.028 m Length of shaft (L) = 0.335 m Number of teeth = 16 Gear Pitch (P) = MT/2 = 0.008*16/2 = 0.128/2 =0.064 m Module (m) = 0.008 m Mass Moment of Inertia (I) = MR2/2 = 4*0.0142 = 0.0039 Polar Moment of Inertia (J) = (do4 di4)/32 = (0.0284 0.0264)/32 = (4.953X10-7)/32 = 1.548 X 10-8 Maximum Torque on bicycle is given by T = (Mass of rider x g) L Where L = Length of pedal crank in m g = 9.81 m/sec2 (Assume mass of rider = 60 kgs) S.No Name Notation Unit Value 1. Ultimate Torque Tmax Nm 3500 2. Max.Speed of shaft Nmax rpm 6500 3. Length of Shaft L mm 250 Design & Fabrication of Shaft Drive for Bicycle International Journal of Emerging Engineering Research and Technology 47 = 60 x 9.81 x 0.335 = 197.2 Nm Power (P) = 2NT / 60 = (2 x 110 x197.2) / 60 = 2271.5 watts Shear Stress () = T/J = (197.2)(7209) /1.548 X 10-8 = 9.18 X 1013 N/m4 Max.Shear Stress (max) = TRo/J = (197.2)(0.014) / (1.548 x 10-8) = 17.83 X 107 Bending moment (M) = EI / R Where E = Youngs modulus I = Moment of Inertia R = Radius (Ro) M = (105 X 0.0039)/ 0.014 = 29.25 Rate of twist = T/GJ = 197.2/(36.75)(1.548X10-8) = 3.46 X 108 Shear Strain = (rate of twist) = 7209 X 3.46 X108 = 2.49 X 1012 = TL/GJ = (197.2)(0.335)/(36.75)(1.548 X 10-8) = 66.06/(5.68X10-7) = 1.163X109 Torsion is the twisting of an object due to an applied torque. It is expressed in newton metres (Nm), In sections perpendicular to the torque axis, the resultant shear stress in this section is perpendicular to the radius. For shafts of uniform cross-section the torsion is: T is the applied torque Nm. is the maximum shear stress at the outer surface JT = Jzz for concentric circular tubes r is the distance between the rotational axis is the length of the object the torque is being applied to or over. is the angle of twist in radians. G is the shear modulus or more commonly the modulus of rigidity (GPa), ro outer radius Torsion (T) = JT.G/L = (1.548 X 10-8)(36.75)(1.163 X 109) / 0.335 Torsion (T) = 1974.9 Nm Deflection (YMax) = ML2 /2EI = (29.25 X 0.3352) / (2 X 105 X 0.0039) = 4.008 m Max.Deflection = T X do / 2 / I = 29.25 X 0.014 / 0.0039 = 105 Max.Shear Stress (max) = (29.25 X 0.014) / (1.548 X 10-8) = 26.45 X 107 Pa Torque Transmission Capacity (T) is given by T = Ss x (do4 di4)do / 16 (Assume shear strength (Ss) = 360 to 1200 Mpa) T = 360 X (0.0284 0.0264)0.028 / 16 = 3.120 X 10-7 N-m Tensional buckling capacity = Tensional Buckling Capacity = (t x L2t) / .2r3 = (0.003 x 0.3352 x 0.003) / (1 0.232).2x0.0143 = (1.01 x 10-6) /(0.947(5.48 x 10-6) = 3.71 X 10-4 m Bending Vibration Frequency is given by Fvb = (p2 / 2L2)(EIx / mi ) = (7.73 X 10-3)/(2 X 0.3352).(105 X 0.0039)/0.204 = (0.0344).2.007 M.Rama Narasimha Reddy etal. International Journal of Emerging Engineering Research and Technology 48 = 1.4166 X 0.0344 = 0.0487 6. RESULT S.no Parameter Symbol Units Value 1. Gear Pitch P m 0.064 2. Moment of Inertia I Kg.m2 0.0039 3. Polar Moment of Inertia J m4 1.548 X 10-8 4. Torque T Nm 197.2 5 Power P Watts 2271.5 6 Shear Stress Pa 9.18 X 1013 7 Max.Shear Stress max Pa 17.83 X 107 8 Bending Moment M N-m 29.25 9 Shear Strain - 2.49 X 1012 10 Angle of twist oc 66.63 11 Torsion Nm 1974.9 12 Deflection m 4.008 13 Max.Deflection max m 105 14 Torque Transmission Capacity T N/m 3.12 X 10-7 15 Tensional Buckling Capacity TC m 3.71 X 10-4 7. CONCLUSION Firstly the project were unable to be completed with the drive shaft due to various problems around circumference of the bicycle ,later on this was realized to run successfully with two bevel gears at both end of the drive shaft. The presented work was aimed to reduce the wastage of human power (energy) on bicycle riding or any machine, which employs drive shafts; in general it is achieved by using light weight drive shaft with bevel gears on both sides designed on replacing chain transmission. The presented work also deals with design optimization i.e converting rotary motion in linear motion with aid of two bevel gears. Instead of chain drive one piece drive shaft for rear wheel drive bicycle have been optimally designed and manufactured for easily power transmission. The drive shaft with the objective of minimization of weight of shaft which was subjected to the constraints such as torque transmission , torsion buckling capacity , stress, strain , etc The torque transmission capacity of the bicycle drive shaft has been calculated by neglecting and considering the effect of centrifugal forces and it has been observed that centrifugal force will reduce the torque transmission capacity of the shaft. The stress distribution and the maximum deformation in the drive shaft are the functions of the stacking of material. The optimum stacking of material layers can be used as the effective tool to reduce weight and stress acting on the drive shaft. The design of drive shaft is critical as it is subjected to combined loads. The designer has two options for designing the drive shaft whether to select solid or hollow shaft. The solid shaft gives a maximum value of torque transmission but at same time due to increase in weight of shaft, For a given weight, the hollow
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