The most commonly used chain for drives is the singlestrand standard series roller chain. Provide means of connection and disconnection of engine with rest of power train without shock and smoothly. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. Anirvan dasgupta is a faculty in mechanical engineering at iit kharagpur since 1999. When the two gear are mating together, they rotating in opposite direction to each other. Multiplestrand roller chains are used to provide increased power capacity without the need for increasing the chain pitch or its linear speed. Gears gears, gear trains and gear box presented by ujjwal nagda 2. Introduction to gear trainsintroduction to gear trains.
Ordinary gear trains have axes, relative to the frame, for all gears comprising the train. Helical, bevel, worm, rack and pinion gears basics only. Module 15 3 hr gear trains kinematics of machines nptel, compound and epicyclic gear trains. Planetary gear trains are one of the main subdivisions of the simple epicyclic. Chapter 4 gear trains theory of machine, mechanical. Planetary gear trains pdf planetary gear is one of the epicyclic gear, which is a gear system consisting of. These notes are of made easy coaching institute, new delhi. Types of gear trains basic, formula and numerical problems approach for gate duration. F effort force n, lb f w load force or weight n, lb f r gear wheel inside diameter m, in. Jul 03, 2019 epicyclic gear train nptel pdf to excel pdf files kinematic analysis of synchromesh, machine tool gear box, differential gear box self study 3. This text will not deal with the stress analysis aspects of gear design. Circumferential velocities in a complex gear train have 3. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can rotate.
Gear train, internal and epicyclic gearing infocobuild. Epicyclic gear train nptel pdf in the first three types of gear trains, the axes of the shafts over which the gears are mounted are. This is a twodimensional case which allows for observation in a plane. The gear trains is having only one gear on each shaft is known as simple gear train. Another class of gear train has wide application, the epicyclic or planetary train. Understand gear trains and how to calculate ratios.
Gear ratio is numbers of teeth of larger gear to smaller gear. Introduction, static balancing, dynamic balancing, transferring of a force from one. Thoery of mechanisms and machines gears prepared by. Gears and gear trains study notes for mechanical engineering.
Stadtfeld introduction the most basic case of a gear train is the transmission of rotation and power between two parallel shafts. Therefore gear 1 is driver and gear 2 is driven when the motion of the gear drivers in opposite. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. Analysis of gear trains type of course intended audience prerequisites course duration exam date. The smallest number of teeth on a spur pinion and gear, onetoone gear ratio, which can exist without interference is np. Pressure angle is the angle between the pressure line and common tangent to pitch circles. As gear rotate, the line of contact goes on shifting parallel to the shaft. For more videos click on playlist link shown below v kinematics of machinery komtom degree. Textile engineering mechanics of textile machinery nptel. Planetary gearboxes are used frequently to match the inertias, lower the motor speed, boost the torque, and at the same time.
Epicyclic gear train nptel pdf merge helical gearing, in which the teeth are cut at an angle with the axis of rotation, was developed after spur gearing and has the advantages that has the smoother action and tends to be trainw fig. Gear train with simple gear train engineers gallery. Types of gear train and velocity ratio calculation techminy. Recognize different gearing systems and relative advantages and disadvantages between them. Simple gear trains, compound gear trains for large speed reduction, epicyclic gear trains algebraic and tabular methods of finding velocity ratio of epicyclic gear trains. Yi zhang with susan finger stephannie behrens table of contents. Basic mechanical engineering covers a wide range of topics and engineering concepts that are required to be learnt as in any undergraduate engineering course.
If a number of bodies are assembled in such a way that the motion of one. Pintz cleveland state university cleveland, ohio prepared for lewisresearchcenter under grant nag3o186 nlsa nationalaeronautics and spaceadministration sclentlllcand technical informationbranch 1984. Jan 24, 2008 lecture series on kinematics of machines by prof. Determine the speed of sliding between the gear teeth faces at the point of engagement, at the pitch point and at the point of disengagement, if the smaller gear is the driver. See the above two pictures to understand how the gear reduction ratio can vary from 1. Asok kumar mallik department of mechanical engineering iit kanpur. Following are the different types of gear trains, depending upon the arrangement of wheels. Compound gear train in this type, two or more gears are. Ii lecture 36 force analysis examples lecture 37 gear kinematics lecture 38 gear trains i lecture 39 gear trains ii lecture 40 gear trains iii. Whenever a change in the speed or torque of a rotating device is needed, a gear train or one of its cousins, the belt or chain drive mechanism, will usually be used. Gear trains simple, compound and epicyclic gear trains. The systems include spur gearing in which the axes of the shafts connected are parallel note helical gearing is the name given to a type of spur gearing in which, although the axes of the shafts are parallel, the teeth are cut on helices instead of straight across the wheel parallel to the axes.
Jul 19, 2017 apr 23, 2020 chapter 4 gear trains theory of machine, mechanical engineering mechanical engineering notes edurev is made by best teachers of mechanical engineering. Gear trains train of gears widely used on machines to transfer motion from one element to many elements. If the transmission of rotation should occur with a constant ratio, which means that in case of a con. They are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wrist watches etc. The contact of two teeth takes place over the entire width along a line parallel to the axes of rotation. Enable speed reduction between engine and the drive wheels in. Pressure line is the common normal at the point of contact of mating gears along which the driving tooth exerts force on the driven tooth. Tooth load and torque calculations in epicyclic gear trains. Nptel mechanical engineering kinematics of machines. Recognize different gearing systems and relative advantages and.
The course is expected to help students in their basic understanding and use of kinematic analysis. Pdf me6401 kinematics of machinery kom books, lecture. Gear design objectives understand basic principles of gearing. Gear trains speed ratio, train value parallel axis gear trains epicyclic gear trains. In helical gear teeth are part of helix instead of straight across the gear parallel to the axis. Design of machinery an introduction to the synthesis and. Gears terminology, fundamental law of gearing, involute profile. Mar 29, 2020 epicyclic gear train nptel pdf merge sijthre. The geometry of gears theory of machines engineering. Types of gears gear and its types mechanical gears. Theory of machines is an applied science of the relationships between geometry and relative motion of the parts of the machine, and concerns to the forces which act on those parts. Gear trains are widely used in all kinds of mechanisms and machines, from can openers to aircraft carriers. It is decided that the topics on dynamics listed above i to v will be covered in the course on dynamics of machines whereas. Gears is a positive drive which transmits exact velocity ratio from one shaft to another shaft, gear drive is used when the distance between driver and follower is very less, when two or more gears are made to mesh with each other to transmit power from one shaft to another, the combination is called gear trains gears.
K l university department of mechanical engineering material. Introduction to mechanisms carnegie mellon school of. In figure 76b a compound ordinary train is seen to be one in which two or more gears may rotate about a single axis. Provide a varied leverage between the engine and the drive wheels provide means to transfer power in opposite direction. Download me6401 kinematics of machinery kom books lecture notes syllabus part a 2 marks with answers me6401 kinematics of machinery kom important part b 16 marks questions, pdf books, question bank with answers key, me6401. A complete gear train design will necessarily involve considerations of strength of materials and the complicated stress states to which gear teeth are subjected.
Theory of machines institute of advanced studies in. The disc with teeth on their periphery is known as gear. This chapter will explore the theory of gear tooth action and the design. Dec 05, 2015 the epicyclic gear trains are useful for transmitting high velocity ratios with gears of moderate size in a comparatively lesser space. Detailed course content with modules for video lectures module 1 3 hr.
The gear train is classified into following types, simple gear train compound gear train riveted gear train epicyclic gear train 1. The loads applied to gear trains can vary from practically fig. Image from blog of haja sherief image from hpi racing image from proquest image from sandia national labs image from piaget image from fortune, apr. This video is part of the content developed by nptel, a joint initiative of all iits and iisc. Planetary epicyclic gear ratios equations and calculators. Lower and higher pairs, degrees of freedom, various types of mechanisms, their inversions and. Design, mechanical engineering, walchand institute of technology, solapur403, maharashtra, india 2professor, mechanical engineering, walchand institute of technology, solapur403, maharashtra, india abstract planetary gear trains are extensively used for the power transmission and are the most critical component. Understand geometry of different gears and their dimensional pro perties. Gear surfaces coated with boundary additive or antifriction. When pinion is the driver, it results in step down drive in which nptl output speed. Helical gearing, in which the teeth are cut at an angle with the axis of rotation, was developed after spur gearing and has the advantages that has the smoother action and tends to be trainw fig.
This document is highly rated by mechanical engineering students and has been viewed 1950 times. Kinematics of gears and gear trains it is decided that the topics on dynamics listed above i to v will be covered in the course on dynamics of machines whereas the topic a above will be covered in kinematics of machines course. Mechanical engineering kinematics of machines nptel. Gear trains image from simon fraser university image from jtekt torsen na, inc. Gear train it is defined as two or more gears are made to mesh with each epicyclic gear train the axes of the shafts over which the geaar are mounted, may move relative to a fixed axis. The variable gear train is often coupled with a clutch. This is sometimes referred to as conepulley backgearing because of its use within the cone pulleys of certain types of machine tools. Gears is a positive drive which transmits exact velocity ratio from one shaft to another shaft, gear drive is used when the distance between driver and follower is very less, when two or more gears are made to mesh with each other to transmit power from one shaft to another, the combination is called gear trains. The course will demonstrate various concepts by working out problems relevant to real life applications of mechanisms. They learn how to build the transmission part of a vehicle by designing gear trains with different gear ratios.
Once students learn the principles behind gear ratios, they are put to the test in two simple design activities that illustrate the mechanical advantages of gear. The number of teeth for spur gears is given by where k 1f fll1 for fulld tht th08f tbt th d ldepth teeth, 0. Clutch fully depressed the clutch is fully disengaged when the pedal is fully depressed. Bevel gearing in which the axes of the shafts intersect and skew or spiral gearing in which the. Divided into three parts, this book lays emphasis on explaining the logic and physics of critical problems to develop analytical skills in students. In this type of transmission system, the driver has to manually select and engage the gear ratios. Enable power transmission at varied angles and varied lengths.
A gear is a mechanical device that transmits rotary motion by changing the magnitude and line of action of the effort force. Epicyclic gear train nptel pdf automatic transmission has not better fuel economy. In gear train, combination of two or gears are used to transmit power. These types of gear trains are used widely in automobile manual transmission systems. Figure 76a shows a simple ordinary train in which there is only one gear for each axis. If the mating gear has more teeth than the pinion, that is. Theory of machine study notes hand written tom free study. In the first three types of gear trains, the axes of the shafts over which the gears are mounted are fixed relative to each other. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. The input gear has 20 teeth and the output gear has 100 teeth. Theory of machines is an applied science of the relationships between geometry and relative motion of the parts of the machine, and concerns to the forces which. The first gear known as the driver has 12 teeth, the second gear called the idler has 16 teeth, and the third gear. Rathindranath maiti, department of mechanical engineering, iit kharagpur.
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