To define a train, consider that it has always the arm r, a gear of the planet and a main gear. Working out planetary gear turns ratios working out the gear ratio of a planetary gear train can be. An epicyclic gear train also known as planetary gear consists of two gears mounted so that the center of one gear revolves around the center of the other. Pdf the mechanical efficiency of epicyclic gear trains. Epicyclic gearing or planetary gearing is a gear system consisting of one or more outer, or planet, gears or pinions, revolving about a central sun gear or sun wheel. The book is profusely illustrated and analyzes many applications. Design of machinery an introduction to the synthesis and. A carrier connects the centers of the two gears and rotates to carry one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. If all gears of this mesh have the same module, calculate the number of teeth on gear 6. The epicyclic gear first analysed here have the following components. Plane t a r y gear tra i n s consis t o f the follo w i n g. Gear c compound epicyclic gear trainsun and planet gear in an epicyclic gear train, as shown in figure, the wheel c is keyed to the shaft b and wheel f is keyed to shaft a.
Two inputs are needed to obtain a predictable output. Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train mechanism find, read and cite all the research you need on. Obviously, since equation 20 must hold for the power. 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. Publishers pdf, also known as version of record includes final page, issue and. The gear b meshes with gear a and has its axis on the arm at o2, about which the gear b can rotate. An epicyclic train consists of two threecomponent elements of the kind examined above. A gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical system to another, with some gear ratio performing a mechanical advantage epicyclic gearing or planetary gearing is a gear system consisting of one or more outer gears, or planet gears, revolving about a central, or sun gear key facts. Calculate the holding torque on gear box cases it is assumed that the student is already familiar with the following concepts. 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. Design, load analysis and optimization of compound. Mullers discovery of their perfect analogy to the simple epicyclic drive trains. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other.
O e of the prime and biggest use of a planetary gearbox is for running the armature of a wind turbine. Also different methods like tabulation and formula methods are discussed which are used to solve the questions based on planetary gear train. Planetary gear train dynamics journal of mechanical design. The planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. Table 1 comparison of parallel shaft vs epicyclic gear trains. Planetary gear trains pdf planetary gear is one of the epicyclic gear, which is a gear system consisting of. The mechanical efficiency of epicyclic gear trains. Suppose an epicyclic gear train has 2 gears gear a and gear b and an arm arm c. A carrier connects the centres of the two gears and rotates to carry one gear, called the planet gear, around the other, called the sun gear. The term power transmission is defined as the move ment of. Gear train conguration appendix a8 another interesting design aspect is that the gear train reverts back to the axle about which the pinion turns. The epicyclic gear train with bevel gears is used in 1. Epicyclic gearing requires a stepbystep process to make it work, and some of the steps are not necessarily intuitive. Another class of gear train has wide application, the epicyclic or planetary train.
In this paper, graph theory is used for the study of epicyclic gear trains or planet gear trains e. Software gto provides the required results in a very short time. The stationary gear sun gear or ring gear can be referred to as the central gear. As such, this article aims to provide assistance and guidelines for people designing epicyclic gear trains for the first timeand perhaps, if you will, ease their degree of suffering. The wheels d and e rotate together on a pin fixed to the arm g. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. 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. Aug 05, 2015 working and construction of epicyclic gear train. Choosing which piece plays which role determines the gear ratio for the gearset. A carrier connects the centers of the two gears and rotates to carry one gear, called the planet gear, around the other, called the sun gear. Planetary gear trains are one of the main subdivisions of the simple epicyclic. Gear trains image from simon fraser university image from jtekt torsen na, inc. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1.
Gear trains theory of machines engineering reference. Introduction to gear trainsintroduction to gear trains. These drives receive an unusually clear treatment because at dr. But in case of epicyclic gear trains, the axes of the shafts on which the gears are mounted may move relative to a fixed axis.
A thorough understanding of the sometimes difficult material is facilitated through the use of both schematic and symbolic diagrams. In this investigation is presented a systematic approach for the modelling and analysis of power split transmissions which include an epicyclic gear train, in various configurations, as they are. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. In this case, the curve traced by a point on the pitch circle of the planet is a hypocycloid. This is sometimes referred to as conepulley backgearing because of its use within the cone pulleys of certain types of machine tools. The planet and sun gears mesh so that their pitch circles roll without slip. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. A network theory for variable epicyclic gear trains. Epicyclic gear train problems and solutions pdf best of all, they are entirely free to find, use and download, so there is no cost or stress at all. This plot was created using the matlab file ratioselect. Gear 2 attached to shaft a dives the epicyclic gear train at 800 rpm in the clockwise sense, when viewed from right. Epicyclic planetary gear system 3d cad model library. Following are the different types of gear trains, depending upon the arrangement of wheels. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train.
Planetary epicyclic gear ratios equations and calculators. Design, load analysis and optimization of compound epicyclic. The first element comprises the external sun gear 1 and planet 2. One of the planetary gearsets from our transmission has a ring gear with 72 teeth and a sun gear with 30 teeth. In case there is a third gear there will be 3 trains and then 3 equations. An epicyclic gear train also known as planetary gear consists of two gears mounted so that the centre of one gear revolves around the centre of the other. A pgt has been represented by its functional schematic, structural and kinematic graph. Feb 28, 2017 the planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. Epicyclic gear train with bevel gear the bevel gears are used to make a more compact epicyclic system and they permit a very high speed reduction with few gears. This lesson tells about basics of planetary gear train. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. One is that the bushing needs to be wider to t over the cap on the pinion.
An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of a fixed, outer gear ring, or ring gear, sometimes called an annular gear. What links here related changes upload file special pages permanent link page information wikidata item. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. 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. 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. 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. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. 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.
The following 72 files are in this category, out of 72 total. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. Each of these three components can be the input, the output or can be held stationary. Determine the speed and the sense of rotation of the output shaft b. This userfriendly windowing system can access help files, display the functional representation of a mechanism, optimize the gear ratios for epicyclic gear trains and present the numerical. In this case, the planet gears have 12 teeth, the sun gear has 18 and the ring gear has 42 teeth. Planetary gear system could be used to secure higher gear ratio in compact space. Mar 30, 2016 epicyclic gear train with bevel gear the bevel gears are used to make a more compact epicyclic system and they permit a very high speed reduction with few gears. A network theory for variable epicyclic gear trains technische. Describe three types of epicyclic gear boxes solve gear box ratios. In the first three types of gear trains, the axes of the shafts over. Apart from this, some objective questions have also been discussed in detail which were asked in previous years in engineering services examination. A model to simulate the dynamic behavior of a single stage planetary gear train with. They are great speed variation mechanisms, and are often.
The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. A network theory for variable epicyclic gear trains citation for published version apa. 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. Calculate the input and outputs speeds and torques of gear boxes. Pdf the paper presents an epicyclic gear train dynamic mathematical. In the first three types of gear trains, axes of shafts over which the gears are mounted are fixed relative to each other 112320. What is the advantage and disadvantage of a epicyclic gear. There would be numerous applications of planetary gearbox, but i will anser with the one which im sure about. The volume of the gear train with spur gears is reduced by 22.
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