Find materials for this course in the pages linked along the left. The designer shall consider the intended method of construction temporary or permanent casing, slurry drilling, etc. Lecture 34 lecture34 lecture 34 lecture 34 members subjected to combined loads combined bending twisting in some applications the shaft are. The ratio of mp to my is called as the shape factor f for the section. Shaft design introduction standard diameters of shafts torsion.
Compare combined stresses to suitable allowable stresses. Plans have been designed to treat flows ranging between. Easy way to draw shear force diagram and bending moment diagram lecture 6. There are two major types of splines used in industry. Estimating stress concentrations stress analysis for shafts is highly dependent on stress concentrations. Schedule and reading assignment please see unterhausen. Standard shaft elements such as shoulders and keys have standard proportions, making it possible to estimate stress concentrations factors before determining actual sizes. Machine design part i is the first course in an indepth three course series of machine design. The gas turbine operates on an open cycle consisting of a compressor, a combustor, and a turbine combined in series figure 2. Highspeed shafts require not only higher shaft stiffness but also stiff bearing supports, machine housings, etc. Determine torque in shafts from gears, pulleys, sprockets, clutches, and. Consequently, the material near the center contributes little to the torsional capacity of the shaft.
Pdf the objective of this chapter is to introduce the concepts and principles of shaft design. The difference between a shaft and an axle is that the shaft rotates to transmit power, and that it is subjected to fatigue. Lecture 34 design of shafts lecture series on design of machine elements i by prof. Drilled shafts design and construction slide 34 of 51 1. Shaft design based on strengthshaft design based on strength asme design code ductile material. The specification and design of transmission shafts is of special significance in the layout of vehicle transmissions. Shafts are designed on the basis of strength or rigidity or both. Splines provide a more uniform circumferential transfer of torque to the shaft than a key. If you have watched this lecture and know what it is about, particularly what mechanical engineering topics are discussed, please help us by commenting on this video with your suggested description and title. Stress concentrations depend on size specifications, which are not known the first time through a design process. Video is not complete and should be design of shafts not design of strength, and.
As shown in the previous lecture, shear stresses are smallest near the center of the shaft and the moment arms of the forces due to these stresses are also small. Lecture series on design of machine elements i by prof. Mounting type range capacity range cost required e. Lecture notes elements of mechanical design mechanical. Mechanical design of machine components may also be used to teach an upper level course. Numerical problems on shaft design 1 a shaft is supported by two bearings which are placed 1m apart. 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.
Unit vi shafts design of solid and hollow shafts for strength and rigidity design of shafts for combined bending and axial loads shaft sizes. Design a reliable and simple test rig to test shaft. Definition of shaft and its explanation design of machine video lecture on definition of shaft and its explanation from design of shafts, keys and couplings chapter of design of. Determine suitability of shaft design andor necessary size of shafting. As shafts are subjected to fluctuating bending and torsional stresses. J e shigley et al, mechanical machine design, ed 4 to 7, mcgraw hill. Lecture notes solid mechanics civil and environmental. In order to accommodate courses of varying emphases, considerably more material has been presented in the book than can be covered effectively in a single threecredithour course. Shigleysmechanical engineering design interference with helical gears on spur and gear with onetoone gear ratio, smallest number of teeth which will not have interference is k 1 for full depth teeth. They convert the chemical potential energy of the fuel to mechanical energy. Pdf shigley mechanical engineering design solutions manual. For design purposes it is necessary to find the principal stresses. Mechanical engineering design of machine elements i nptel.
To check the design of propeller shaft mathematically with a conventional material. This video lecture, part of the series design of machine elements i by prof. Design system to transmit power between parallel shafts three possibilities from many possibilities belt, chain or gear. Lecture 2 machine design free download as powerpoint presentation. Shaft design both stress and deflections need to be considered as both could be critical usually, shafts are designed based on stress considerations and then the deflections are calculated when the geometry is completed natural frequencies in both torsion and bending are also evaluated to avoid resonance after the geometry is. Shafts and portals of tunnels emphasis on design verifica tions. Most shafts have circular cross sections, either solid or tubular.
Shafts are usually available up to 7 meters length due to inconvenience in transport. Shaft design objectives compute forces acting on shafts from gears, pulleys, and sprockets. To check also design of propeller shaft mathematically with composite material. Design of shafts couplings ppt linkedin slideshare. Calculate forces on teeth of spur gears, including impact forces associated with velocity and clearances. Retaining rings retaining rings are used on shafts to maintain the axial position of components. Shaft design based on strengthshaft design based on strength ai l t ti axial stress continue. Design based on strength is to ensure that stress at any location of the shaft does not exceed the material yield stress. Shaft stresses similar approach can be taken with any of the fatigue failure criteria equations are referred to by referencing both the distortion energy method of combining stresses and the fatigue failure locus name. Highspeed shafts must be carefully checked for static and dynamic unbalance and for firstand secondorder critical speeds.
The design of shafts in some cases, such as those for turbopumps, is dictated by shaft. Machine design design of shafts me lectures by dr shashank mohan garg. Lecture 5 keys and keyways 51 introduction a key, fig. Design and optimization of automobile propeller shaft with. Design and optimization of 2stage reduction gearbox. 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. The machine design coursera series covers fundamental mechanical design topics, such as static and fatigue failure theories, the analysis of shafts, fasteners, and gears, and the design of mechanical systems such as gearboxes.
Opti 222 mechanical design in optical engineering 71 hollow shafts thick tubes. Construction procedures and lrfd design methods geotechnical engineering circular no. Chapter 7 shafts and shaft components lecture slides. Relative characteristics of gear types 1 best 5 worst ratio power speed relative space approx. 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. Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. Design of keys stresses in keyscotter jointsspigot and socket, sleeve and cotter, jib and cotter jointsknuckle joints. Maiti, department of mechanical engineering, iit kharagpur. Lecture 34 lecture34 lecture 34 lecture 34 members. Varma in figure 4, my is the moment corresponding to first yield and mp is the plastic moment capacity of the crosssection. Brittle fracture initiated by stress concentration. Spur gear design and selection objectives apply principles learned in chapter 11 to actual design and selection of spur gear systems.
Design and optimization of a formula sae vehicle a major qualifying project submitted to the faculty of worcester polytechnic institute in partial fulfillment of the requirements for the degree in bachelor of science in mechanical engineering by. To perform fem analysis with conventional as well as composite materials. Design of shaft the shafts are designed on the basis of strength, rigidity and stiffness. 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. Standard shaft elements such as shoulders and keys have standard proportions, making it possible to estimate stress. To investigate the existing design of automotiveautomobile propeller shafts. As the shafts transmitting power are subjected to fatigue loading, therefore higher factor of safety of 3 to 4 is used on the basis of yield strength for static load analysis. Design and performance of a gasturbine engine from an. Design of shaft a shaft is a rotating member usually of circular crosssection solid or hollow, which transmits power and rotational motion. When a drilled shaft is constructed with a permanent casing, the skin friction along the. Strength andresistance to deformation must therefore be carefully considered during the design process. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices.
Design information on polygons is available from general polygon. Keys and keyways 51 introduction university of babylon. William kinkead, me connor morette, me adrian pickering, me zachary sears, me james waldo, me. Shaft diameters are a key factor in determining the centre distance of a gearbox, and thus its size. Principles of mechanical design prof ahmed kovacevic. In analysis situation, can either use these customized equations for factor of safety, or can use standard approach from ch. Determine allowable force on gear teeth, including the factors necessary due to. Hence shafts are designed using degoodmans criteria of failure as it is conservative as well as optimum as per design. General design principles lecture31 levers types and design procedures lecture32 brackets types design principles module8 lecture33 shafts static loading.
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