Design of shaft stress analysis in shafts a line shaft rotating at 200 r. Introduction 715 sleeve couplings or muff couplings 716 clamp or compression couplings. The single flexing coupling is for use in the case where shafts are supported by three bearings. Shafts are designed on the basis of strength or rigidity or both. Couplings are used to connect sections of long transmission shafts and to connect the shaft of a driving machine to the shaft of a driven machine. Head shafts or stub shafts are shafts directly connected to the motor.
Keys and keyways 51 introduction university of babylon. Find the diameter of a solid steel shaft to transmit 30 kw at 200 r. Understand basic types of universal joints and how and when theymay be. Couplings can be rigid or flexible depending on the alignment accuracies of the system and torque requirements. Pdf a textbook of machine design keys and coupling. Determine the diameter of the shaft, neglecting the bending moment on the shaft. Shaft keys are important machine components designed to transmit torque and rotative force.
Shaft keys, shaft key design, rectangular keys, square keys, woodruff keys, gib keys, taper keys. They are rigid sleeve or muff couplingsthis is the basic type of coupling. Shafts are mounted in bearings and transmit power through devices such as gears, pulleys, cams and clutches. The shaft may be assumed to be made of mild steel with an allowable shear stress of 42 mpa. F tangential force acting at the circumference of the shaft, d diameter of shaft, l k. Sunk keys half in the keyway of the shaft and half in the key way of hub. Pdf design and failure analysis of flange coupling with. Keys and coupling keys a key is a piece of metal inserted between shaft and hub to connect these together in order to prevent relative motion between them types of keys 1. The parts carried by axle or shaft are fastened to them by means of keys or splines and. A 600mm diameter pulley is mounted at a distance of 300mm to the right of left hand bearing and this drives a pulley directly below it with the help of belt having maximum tension of 2250 n.
Rigid couplings con t zthe load path is from the driving shaft to its flange, through the bolts, into the mating flange, and out to the driven shaft. Chapter 11 keys, couplings and seals keys parallel keys uf abe. Sleeve, a hollow cylinder, is fitted on the ends of input and output shaft with the help of a sunk key. The sunk keys are provided half in the keyway of the shaft and half in the keyway of the hub or boss of the. Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. At the same time jaw couplings have good misalignment characteristics and can transmit high torque. August 15, 2007 3 standard diameters of shafts 5 to 8 14 3 to 5 18. Recognize many types of couplings and their advantages and disadvantages. Flexible couplings are used to transmit torque from one shaft to another when the two shafts are slightly misaligned. Pdf a textbook of machine design keys and coupling ahmed. Shaft coupling design article containg design procedure and numerical problems of different types of couplings commonly used. There are many types of couplings that fall under the rigid couplings category. Introduction bush pin type flange coupling is used to connect of shafts which having a small parallel misalignment, angular misalignment or axial misalignment. Problem on design of key design of machine youtube.
Woodruff keys have deeper penetration useful for smaller shafts to prevent key from rolling when used near a shoulder, the keyway stress concentration interferes less with shoulder than square keyway shigleys mechanical engineering design fig. Design of flanged coupling unprotected and protected type. Unit iii shafts cause of failure in shafts, materials for shaft, stresses in shafts, design of shafts subjected to twisting moment, bending moment and combined twisting and bending moments, shafts subjected to fatigue loads, design for rigidity. Design based on rigidity is to ensure that maximum deflection because of bending and maximum twist due to torsion of the shaft is within the allowable limits. Transmission or line shafts are relatively long shafts that transmit torque from motor to machine. In order to have a greater length, it becomes necessary to join two or more pieces of the shaft by means of a coupling 3. This consists of a pipe whose bore is finished to the required tolerance based on the shaft size. Mechanical shaft keys are used for transferring torque in automotive powertransmission systems there are many shaft keys for costeffective and efficient power transmission, which includes square keys, parallel keys, rectangular keys, woodruff keys, taper and gribhead keys, and feather keys. Design of flan ge coupling includes the design of hubs, flanges, key and bolts 4. Machine design objectives after studying this unit, you should be able to describe types of shafts, take decisions to select the materials for shaft, estimate shaft diameters in different segments along length, and design couplings for shafts.
Keys are used as temporary fastenings and are subjected to consider able crushing and shearing stresses. Chapter 10 keys and couplings machine design, mechanical engineering mechanical engineering notes edurev notes for mechanical engineering is made by best teachers who have written some of the best books of mechanical engineering. General application or uses to transmit power from driver shaft to driven shaft. Iso 1940,1 balance quality of rotating rigid bodies. Shaft keys types and their design bright hub engineering.
Design, manufacturing, and installation errors a key with a square end is likely to damage the shaft when transmitting torque, figure 5. Rigid couplings are used where shafts are already positioned in precise lateral and angular alignment. These shafts usually have four, six, ten or sixteen splines. Their design does not allow for any misalignment between shafts, but are generally able to transmit more power than flexible couplings. Design tapered keys designed to be inserted from the end of the shaft after the hub is in position. Couplings, universal joints, and flexible shafts from sdpsi.
Compare combined stresses to suitable allowable stresses. Standard shaft elements such as shoulders and keys have standard proportions, making it possible to estimate stress. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices. In this example, the test fixture is using torque transducer as torque senor for measuring torque. The taper will impart a compressive contact pressure between the hub and the shaft. The strength o f the members in flange coupling are should be go od enough for app lied load7. Design of shaft a shaft is a rotating member usually of circular crosssection solid or hollow. Stress concentrations depend on size specifications, which are not known the first time through a design process. Design of shafts couplings ppt linkedin slideshare. Keys are used to transmit torque from a rotating machine element to the shaft.
Shaft design objectives compute forces acting on shafts from gears, pulleys, and sprockets. Bores and keyways for flexible couplings inch series. Friction will help transmit torque and provide resistance to axial motion of the hub relative to the shaft. Shafts are usually available up to 7 meters length due to inconvenience in transport. A shaft coupling is a mechanical device used to connect rotating shafts and absorb misalignments between them. Chapter 14 keys and couplings chapter objectives design the section of the most commonly used rectangular key on the basis of torque and allowable shear and bearing stresses in key. Stress analysis for shafts is highly dependent on stress concentrations. Numerical problems on shaft design 1 a shaft is supported by two bearings which are placed 1m apart. Couplings are used when the shafts are in a straight line and are to be connected end to end to transmit power. Shaft must sustain a combination of bending and shaft must sustain a combination of bending and torsional loads. A key is a piece of mild steel inserted between the 18. Keys, couplings and seals material taken for mott, 2003, machine elements in mechanical design keys za key is a machinery component that provides a torque transmitting link between two powertransmitting elements. Design and analysis of bushed pin flexible coupling.
Shaft couplings are available in different sizes and material finishes. Video lecture on problem on design of key from design of shafts, keys and couplings chapter of design of machine for mechanical. Understand principles of splines and analyze appropriate loads. Design based on strength is to ensure that stress at any location of the shaft does not exceed the material yield stress. There are several types of shaft keys, each with their own particular role and application. Countershafts are short shafts between the driver motor and the driven machine. Motion or power can be transmitted through an angle. To connect or couple 2 components which are manufactured separately eg. These shafts usually have four, six, ten or sixteen. Shaft couplings shaft couplings are used to connecetwo shafts in such away that when both shafts rotate, they act as one unit and transmit power from one shaft to other shafts to be coupled may have collinear axes, intersecting axes or parallel axes at a small distance. Nd 2011 keys a shaft which is having single keyway keys are used in couplings. A key is a piece of mild steel inserted between the shaft and hub or boss of the pulley to connect these together in order to prevent relative motion between them. Components such as gears are mounted on shafts using keys.
Tutorial 3 design of shaft key and coupling free download as word doc. Flexible couplings are designed to accommodate misalignment between shafts and various types of load. Precise alignment of the shafts chapter 11 keys, couplings and seals rjm 31604 bolts in carry torque in shear. Construction of formflex couplings design features of 4bolt coupling. Torque is transmitted from input shaft to the sleeve through key and from the sleeve to the output shaft through the key again. Rigid couplings are mainly used in areas where the two shafts are coaxial to each other. Design, solidworks, flexible coupling, rubber and brass bushed, single bush. Couplings should be capable of transmitting the rated torque capacity of the shaft while accommodating any misalignment between the. Mott, 2003, machine elements in mechanical design rigid couplings con t zthe total shear force on the bolts depends on the radius of the bolt circle, d. The coupling shown in the diagram on the right above is suitable for use in cases subject to great radial. In designing a key, forces due to fit of the key are neglected and it is assumed that the.
Shaft couplings design equation and calculator engineers. Tutorial 3 design of shaft key and coupling axle belt. Such shafts are known as splined shafts as shown in figure 6. Chapter 10 keys and couplings machine design, mechanical. In order to have a greater length, it becomes necessary to join two or more pieces of the shaft by means of a coupling shaft couplings are used in machinery for several purposes. Design of shafts, keys and couplings, design the diameter of a shaft on the basis of equivalent twistingbending moment and allowable shear stress, design the. The splined shafts are relatively stronger than shafts having a.
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