This method is extremely methodical, which is appropriate since use of intuition is quite futile with an epicyclic gear train such as the following example. These books contain exercises and tutorials to improve your practical skills, at all levels. Hw 1 problem 1 a 17tooth spur pinion paired with a 50 tooth gear has a diametral pitch of 2. So the absolute speed of a gear is the relative speed with respect to the shaft plus the shafts speed with respect to ground. Epicyclic gear train nptel pdf download n is the gears teeth number, the sign depends on the type of gear and, in sequence is for external gears. A gear a mounted on shaft x having 50 teeth drives the gear b having 75 teeth mounted. The advantages of planetary gear trains are higher torque capacity, lower weight, small size and improved efficiency of the planetary design. Mathematics a circle whose circumference rolls along the circumference of a fixed. 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. Gear trains pdf nptel, gear trains nptel pdf download, gear trains nptel lectures, gear and gear train nptel pdf, gear trains, gear trains theory, gear trains problems, gear trains pdftheory of machine, nptel gear train pdf, gear trains pdftheory of machine for diploma. Pdf dynamic analysis of epicyclic gear trains by means of.
For a simple gear train, we do not need one of the gears in the stage 2 gearpair. Based on the number of degrees of freed om, the epicyclic gear trains can be further categorized as differential and planetary gear trains. Reverted gear train when the axes of the first gear i. An update on the latest gear design software from several vendors, plus what gear design engineers can expect next. Tribology is also in virtually every area of engineering and industry aerospace agriculture automotive. Epicyclic gearing also called as planetary gearing. Another class of gear train has wide application, the epicyclic or planetary train. Epicyclic gear train nptel pdf merge friction losses can be divided into two major categories. Epicyclic definition of epicyclic by the free dictionary. Transportation engineering ii transportation engineering ii lecture series on transportation engineering ii by dr. For a simple gear train, we do not need one of the gears in the stage 2 gear pair. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Experimental analyses of vibration and noise of faulted.
To define a train, consider that it has always the arm r, a gear of the planet and a main gear. The conventional gear trains described in the previous sections are all onedegreeof free dom dof devices. In case there is a third gear there will be 3 trains and then 3 equations. Textile engineering mechanics of textile machinery nptel. Sort by date 1 design unit evaluating new software from smt januaryfebruary 2007. Design, load analysis and optimization of compound. Download limit exceeded you have exceeded your daily download allowance. Gears and gear trains study notes for mechanical engineering. Introduction to epicyclic gear train working and advantages. Nptel video lectures, iit video lectures online, nptel youtube lectures, free video lectures, nptel online courses, youtube iit videos nptel courses. Railway and locomotive engineering internet archive. For the predefined gear ratios, one negativeratio drive and two structurally different positiveratio drives will be designed and compared fig.
In absence of lubricant additives and antifriction coating, gears will be subjected to direct friction. A twostage planetary gear stage is defined using the program. Design, load analysis and optimization of epicyclic gear. A gear train hav ing a relative motion of axes is called planetary or an epicyclic gear train. Often gears are treated as pitch cylinder, which roll together without slip as shown in fig. In an epicyclic gear train, the axis of at least one of the gears also moves. 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. A simple gear train has only one gear on each shaft how does this. If the arm is the input and the planet is the output, the overall gear ratio is 31 3. Introduction to gear trainsintroduction to gear trains. Im designing a gear driven mechanism, and i need to size the motor, assuming some frictional loss in the gears, so i need the cof. In ptolemaic cosmology, a small circle, the center of which moves on the circumference of a larger circle at whose center is the earth and the.
The epicyclic gear trains are useful for transmitting high velocity. A gear whose axis itself is revolving is called a planetary gear. Gear surfaces coated with boundary additive or antifriction. Thediscussed examples illustrate how the presented approach can be extendedfor computing the equivalent inertia. Nptel latest breaking news, pictures, videos, and special reports from the economic times.
Planetary or epicyclic gear train epicyclic gear train. Free pdf ebooks users guide, manuals, sheets about gear trains nptel lectures ready for download. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. 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 trains train of gears widely used on machines to transfer motion from one element to many elements.
Lightweight design for planetary gear transmissions. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Lecture notes tribology mechanical engineering mit. Design of machinery an introduction to the synthesis and. 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 gears are mounted, may move relative to a fixed axis. Nptel mechanical engineering fluid mechanics video introduction and. A fixedring epicyclic gear train is required to have an overall ratio of 5. An epicyclic train is often suitable when a large torquespeed ratio is required in a compact envelope. In an epicyclic gear train, the internal wheels a, b and the compound wheel c and d rotate independently about the axis o. Gear trains image from simon fraser university image from jtekt torsen na, inc.
Pdf dynamic analysis of epicyclic gear trains by means. Kinematics of machines nptel online videos, courses iit. The paper illustrates the application of a systematic technique for thededuction of dynamic equations of epicyclic gear trains. Find materials for this course in the pages linked along the left. Tribology 101 introduction to the basics of tribology. A network theory for variable epicyclic gear trains. Design, load analysis and optimization of compound epicyclic. If the sun gear is to have between 10 to 15 teeth, suggest the most appropriate numbers of teeth for each of the constituent gears. In some cases, such as the automotive differential, one input is. The wheels e and f rotate on a pin fixed to the arm g. Gears kinematics gear machines free 30day trial scribd. Rajat rastogi, department of civil engineering, iit roorkee. Usually, following two types of lubrication mechanisms are commonly used for gear lubrication.
Apr 04, 20 reverted gear train when the axes of the first gear i. Ordinary gear trains have axes, relative to the frame, for all gears comprising the train. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. With the rotation of each element of the gear train in hand, the overall gear ratio becomes easy. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. 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. Most gears are in the hardness range of approximately rc 30 to rc 38 or rc 55 to rc it is interesting to note that oil sample collected after 3 hours of operating gear at rpm no load conition show wear fig. The epicyclic gear trains may be simple or compound. With increase in pitch line velocity, lubricant used should be less viscous in order to min. Gear trains for web faculty of engineering, university of. A gear train is usually made up of two or more gears.
The present work on epicyclic gear trains carries out the design of all the gears, shafts, keys and the loads are calculated for individual gears in the epicyclic gear train system. Thus a gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical system to another. The use of theproposed method is particularly amenable in conjuction with proceduresfor the computerized enumeration of geared kinematic chains. 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. Gears 5 5 epicyclic gear train it is the system of epicyclic gears in which at least one wheel axis itself revolves around another fixed axis.
R is the angular speed of the arm, equal to the input angular speed. The stationary gear sun gear or ring gear can be referred to as the central gear. Asok kumar mallik department of mechanical engineering iit kanpur. In some epicyclic gear trains, we may find two or more planetary gears. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. A gear train is known as an normal gear teach if all the rotating shafts are set up on a commonplace stationary frame and a planetary gear educate pgt if some gears not only rotate. With the right feedback, you can get your software developer to work for you to provide the most relevant features possible. Kinematics of machines nptel online videos, courses. For more videos click on playlist link shown below v kinematics of machinery komtom degree.
Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. To find more books about gear trains pdf nptel, you can use related keywords. All the components are modelled in catia to check the assembly and the. Dynamic analysis of epicyclic gear trains by means of.
For a more involved epicyclic gear train example, please refer to the epicyclic gear train example section. Jan 23, 2015 gears 5 5 epicyclic gear train it is the system of epicyclic gears in which at least one wheel axis itself revolves around another fixed axis. Define gear train and explain different types of gear train 25. Reverted gear train pdf following are the different types of gear trains, depending upon the arrangement of wheels. A key part of gear design software development is customer feedback. It is made up of a number of elements which are interconnected to form the train. Lecture 39 gear train, internal and epicyclic gearing infocobuild. As the weigh is 60%, and half the size of a conventional gear box, it.
List of ebooks and manuels about gear trains nptel lectures. Helical gear the teeth on helical gears are cut at an angle to the face of the gear this gradual engagement makes helical gears operate much more smoothly and quietly than spur gears one interesting thing about helical gears is that if the angles of the gear teeth are correct, they can be mounted on perpendicular shafts, adjusting the rotation angle by 90 degrees. It is a mathematical equation that tells how many values can vary and can help in the first three types of gear trains, the axes of the shafts over which the gears are mounted are ger relative to each. Thediscussed examples illustrate how the presented approach can be extendedfor computing the equivalent inertia of an.
Each element consists of the three components illustrated below. In this train, the blue gear has six times the diameter of the yellow gear the size of the red gear is not important because it is just there to reverse the direction of rotation in this gear system, the yellow gear the sun engages all three red gears the planets simultaneously all three are attached to a plate the planet carrier, and. Following are the different types of gear trains, depending upon the arrangement of wheels. Download our gear trains pdf nptel ebooks for free and learn more about gear trains pdf nptel. A gear train is a combination of gears used to transmit motion from one shaft to another. As the weigh is 60%, and half the size of a conventional gear box, it is very likely to have a misconception. In ptolemaic cosmology, a small circle, the center of which moves on the circumference of a larger circle at whose center is the earth and the circumference of which describes the orbit of one of the planets around the earth. Higher value of t f cause scuffing failure of gears. Two inputs are needed to obtain a predictable output. 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.
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