Problem 1 on design of shaft design of machine youtube. Operations research is the art of giving bad answers to problems to which otherwise worse answers are given. For the design of shafts made of metals with low ductility or fracture toughness, it is customary to apply theoretical stress concentration. Lecture 5 shaft design with solutions gear strength of. Useful solutions for standard problems preface modelling is a key part of design. Yuriy batrak for skf solution factory marine services in the netherlands as part of their service division in shaft alignment. Calculate the loads coming from gears, belts or chains step 4. The person who designs the solution for different engineering problems has to go through the various stages of the design process to arrive at an optimal solution.
When a stepped shaft is to be studied, direct successive integration becomes tedious. Let d diameter of the shaft width of the key w d4 rectangular crosssection nominal thickness h 23w 16d square crosssection. For a shaft subjected twisting moment, the angle of twist is given by, where, t torqe applied. The axial force of gear 5 on shaft c is in the negative zdirection. Shaftdesigner is being developed by intellectual maritime technologies imt headed by dr. Taking the dimensions, forces and other determining factors, the. The axial force of gear 3 on shaft b is in the positive zdirection. The typical shaft layout is a stepped element with a circular crosssection, with a wider crosssection at the centre so that several elements can be mounted on it at its ends, which results in a greater section modulus at the central area where flexion causes greater loads. Shaft design example problem design a shaft to support the attachments shown below with a minimum design factor of safety of 2. Solutions to chapter 10 exercise problems problem 10. Shaft design introduction standard diameters of shafts torsion. Lund uc davis fall 2017 3 some thoughts on optimization all models are wrong, but some are useful. Shaft is supported in selfaligning ball bearings and gears are both 10 pitch, 40 tooth, 20 spur gears.
You may assume that there are no axial loads and that the material selected will be steel with the following properties. Alfa laval solutions to specific centrifugal pump problems 4. Shaft coupling design article containg design procedure and numerical problems of different types of couplings commonly used. The objective of this project is to design a safe shaft given certain dimensions of gears and bearings as well as forces acting on the shaft through the gears and the effect of fillets and keys. Keys are temporary fastening and are always made of mild steel because they are subjected to shearing and compressive stresses caused by the torque they transmit. Keys 4 a key is the piece inserted in an axial direction between a shaft and hub of the mounted machine element such as pulley or gear etc. Shigleys mechanical engineering design chapter 7 shafts and shaft components. Page index listed on this page are all the individual pages in chapter 8 with the exception of the exercise problems. Alternatively, the equation given below can be used to solve for the new shaft size directly.
Shaft design based on strengthshaft design based on strength ai l t ti axial stress continue. Keys design 6 keys are sunk in the shaft and the hub. The shaft design book design charts and calculations for torsional properties of noncircular shafts abstract design charts and tables have been developed for the elastic torsional stress analyses of free prismatic shafts, splines and spring bars with virtually all commonly encountered cross sections. A larger shaft to take the torque will require more horsepower to eliminate wobble. If elected, then place the blade one blade width off the bottom. Shear deflection due to transverse loading of short shafts. Dss engineers, researches, designs, develops and distributes the highest quality cv axles and drive shafts for the aftermarket. Shaft deformations when subjected to torsion, every cross section of a circular shaft remains plane and undistorted. Shigleys med, 10 th edition chapter 7 solutions, page 545 74 we have a design task of identifying bending moment and torsion diagrams which are preliminary to an industrial roller shaft design. Video lecture on problem 1 on design of shaft from design of shafts, keys and couplings chapter of design of machine for mechanical.
An overall shaft design procedure is presented including consideration of bearing and component mounting and shaft dynamics using the asme design code for transmission shafting. At first a design scheme lay out is drawn in which the shape of the. If similar materials must be used, such as often the case in construction e quipment where a steel pin runs inside a steel bore, one of the elements should be harder than the other. Crosssections of noncircular nonaxisymmetric shafts are distorted when subjected to torsion. Nontrivial solutions to this set of simultaneous equations will. Mar 01, 2016 video lecture on problem 1 on design of shaft from design of shafts, keys and couplings chapter of design of machine for mechanical engineering students. The moment of inertia equation for a round shaft is rearranged to solve for diameter. Each page title is hyperlinked to its specific page and can be accessed by clicking on the title. Shaft stresses for rotating shaft for rotating shaft with steady bending and torsion bending stress is completely reversed, since a stress element on the surface cycles from equal tension to compression during each rotation torsional stress is steady previous equations simplify with m m and t a equal to 0. Comprehensive shaft design problems it will be necess. Mechanics and machine design, equations and calculators. The axial force of gear 2 on shaft a is in the negative zdirection. In analysis situation, can either use these customized equations for factor of safety, or can use standard approach from ch. The shaft is supported on bearings and it rotates a set of gears or pulleys for.
Design stresses in shafts august 15, 2007 23 find the torsion in the shaft. Video lecture on problem 1 on design of shaft from design of shafts, keys and couplings chapter of design of machine for mechanical engineering students. To prevent solid buildup on the bottom, a radialblade impeller may be used. Let point c represent the center of the span of the roller. Each shaft is designed for mechanical loads and critical shaft speed.
Calculate the bending moment due to the acting forces. Centrifugal pumps with suggestions as to probable causes and solutions. Check the shear strength of the key against the normal strength of the shaft. In the early stage, approximate modelling establishes whether the concept will work at all, and identifies the combination of material properties that maximize performance. Numerical problems on shaft design 1 a shaft is supported by two bearings which are placed 1m apart.
Useful solutions for standard problems dartmouth college. How correct system design and installation can avoid potential problems 5. 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. Page index listed on this page are all the individual pages in chapter 9 with the exception of the exercise problems. Opti 222 mechanical design in optical engineering 68 torsion example problems torsion problem 1 specifications. Calculate the torque on the shaft from power step 2. July 1984 design of powertransmitting shafts stuart h. Can design key to be weakest link to fail in case of overload. Jul 19, 2017 design of shaft a shaft is a rotating member usually of circular crosssection solid or hollow, which transmits power and rotational motion. It was created as a bridge between imts theoretical expertise and the practical experience in the field of shaft alignment and mounting of skf solution factory marine services. Shaft shown drives a gear set that is transmitting 5 hp at 1750 rpm. 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.
Pdf problem set 8 chapter 17 shafts selected problems jz cls. Machine elements such as gears, pulleys sheaves, flywheels, clutches, and sprockets are mounted on the shaft and are used to transmit power from the driving device motor or engine through a. The axial force of gear 4 on shaft b is in the positive zdirection. 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. However, design method remains the same for axle and spindle as that for a shaft. Useful solutions to standard problems in introduction and synopsis modelling is a key part of design. Determine the value of the critical speed of rotation for the shaft. Design of flanged coupling unprotected and protected type notations used in design. A steel shaft should not run in a steel bore, but it can run in a bronze lined bore e. Due to the uniqueness of solutions, we can be sure that the assumptions made and the solutions found are correct for the torsion problem.
Determine the length of the contact line and the contact ratio. Lecture 5 shaft design with solutions free download as pdf file. Lecture 5 shaft design with solutions gear strength of materials. Dss has the largest and best cv axle coverage in the industry and offers an easy to use ecatalog for easy accurate parts lookups. In the early stage, approximate modelling establishes whether the concept will work at all, and identifies the combination of material properties which maximize performance. Options include specialized shaft software, general beam deflection software, and finite element analysis software. Machine elements such as gears, pulleys sheaves, flywheels, clutches, and sprockets are mounted on the shaft and are used to transmit power from the driving device.