These drives receive an unusually clear treatment because at dr. Nov 02, 2018 xun, chao, jiao, sujuan, chen, yong, and long, xinhua. 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. Gear design objectives understand basic principles of gearing. Epicyclic gear trains egts are commonly used in automatic transmission mechanisms to achieve a set of desired velocity ratios. Compound planetary gear 728 a study on optimization of planetary gear trains 729. Having more teeth in mesh, not shifting the load so abruptly, also reduces. Propelled by their 2016 international blues competition win, the delgado brothers invite audiences to travel with them via their spirited live. Design, load analysis and optimization of compound. Two inputs are needed to obtain a predictable output. The book is profusely illustrated and analyzes many applications.
Tooth load and torque calculations in epicyclic gear trains. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears. Usually, an epicyclical gearing systems are employed to achieve high reduction ratio in a. N is the gears teeth number, the sign depends on the type of gear and, in sequence is for external gears. The homotopy analysis for the nonlinear dynamics of. In the texts chapters, readers can find all the information needed for various types of gear trains, with illustrations and examples. The homotopy analysis for the nonlinear dynamics of planetary gear trains. With planetary gear trains the gears are in constant mesh and gear ratio changes are effected by holding, releasing.
Us3021729a planetary transmission for tractors or the. This accounts for epicyclic gear trains being more quiet than parallel shaft gear trains. In the texts chapters, readers can find all the information needed for various types of. Apr 08, 2019 if there npetl more than one arm in the planetary gear train. The classical lever analogy provides an easy way to study the kine. Understand geometry of different gears and their dimensional pro perties. Introduction to gear trainsintroduction to gear trains most of the pictures and animations are from norton design of machinery. A simple method for calculating planetary gear ratios is described which can be used to determine quickly the potential usefulness of any planetary configurations. Sun gear is located at the center that transmits torque to planet gears orbiting around the sun gear. A practical method to analyze planetary gear train for speed ratio determination is lever analogy.
Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. It was developed under the motto from practice to practice. Understand gear trains and how to calculate ratios. R is the angular speed of the arm, equal to the input angular speed. Planetary gear trains pdf planetary gear is one of the epicyclic gear, which is a gear system consisting of. Planetary gear trains of various functions and designs and with different characteristics are used in reduction gears to obtain compact coaxial designs and high gear ratios and in gear boxes, reversing gears, and clutch mechanisms to obtain convenient.
The book reflects not only teaching, but also the practical experience of the authors. A planetary gear train is a gear train that allows the input and output shaft to be coaxial. The epicyclic gear train family in general has a central sun gear. A reliabilitymodel is presentedfor planetarygear trains inwhich the ring gear isfixed, the sun gear isthe input,and the planet arm isthe output. Optimization, planetary gear trains tangential tooth load, wear tooth load, dynamic tooth load, static tooth load i.
A planetary or epicyclic gear trains comprises of one or more planet gears revolving around a sun gear. With planetary gear trains the gears are in constant mesh and gear ratio changes are effected by holding, releasing or rotating certain parts of the gear train by means of a one way clutch, two. Also the case study to determine the reduction ratio of two stage gear box is discussed. Automatic transmission basics linnbenton community.
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. Pintz cleveland state university cleveland, ohio prepared for lewisresearchcenter under grant nag3o186 nlsa nationalaeronautics and spaceadministration sclentlllcand technical informationbranch 1984. Simple planetary gear trains have a sun gear, a ring, a carrier, and a planet set. Proceedings of the asme 2018 international design engineering technical conferences and computers and information in engineering conference. The authors help gear designers to creatively understand the design of gears, as well as master the mechanical calculations needed. Introduction special layouts of simple planetary gear trains composed planetary gear trains elements of planetary gear train design list of symbols. Planetary gear trains pgts are introduced to undergraduate mechanical engineering students in the course of theory of machines. Introduction a planetary or epicyclic gear trains comprises of one or more planet gears revolving around a sun gear. Simulations of the planetary gear trains obtained using the developed software are presented.
Lightweight design for planetary gear transmissions. The expelled oil enters an oil discharge passage 62 in an oil collection channel 56 adjacent to and. Planetary gear trains are popular in applications where more torque is required from a smaller gearmotor package. 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. All 34 types can be derived from one general form of the simple planetary gear train. Xun, chao, jiao, sujuan, chen, yong, and long, xinhua. The second type uses the planetary gear trains as the basic topological unit. It is a gear system that consists of one or more outer gear planet gear rotating about a central sun gear. A reliability model is presented for planetary gear trains in which the ring gear is fixed, the sun gear is the input, and the planet arm is the output. Another class of gear train has wide application, the epicyclic or planetary train. Sun gear carrier ring gear speed torque direction 1 input output held maximum reduction increase same as input 2 held output input.
The outermost gear, the ring gear, meshes with each of the planet gears. Design, modelling and analysis of a 3 stage epicyclic planetary reduction gear unit of a flight vehicle k akhila1 and m amarnath reddy2 corresponding author. On completion of this short tutorial you should be able to do the following. When there are three or more planets, as is the usual case, care must be made to make sure the teeth of both planets can engage. Small gear driving large gear under drive under drive happens when carrier is the output under drive increases torque decreases speed large gear driving smaller gear overdrive overdrive happens when the carrier is the input if the carrier is held, the gear set goes to reverse. Automatic transmission basics linnbenton community college.
Planetary gears, gear train, is 4460, torque density. Figure 1 shows an epicyclic gear mechanism employing the ravigneaux gear set as the ratio change gear train where the rotating and band clutches are designed as c and b, respectively. Following are the different types of gear trains, depending upon the arrangement of wheels. Venturing on the tracks of humanity and artistry, the delgado brothers new cd two trains, an 11 song collection, may be the most dynamic and soulful work of their 30 year recording career. Plane t a r y gear tra i n s consis t o f the follo w i n g. This book provides comprehensive information for various planetary gear trains, with practical applications and comprehensive references to technical articles. Planetary gear train article about planetary gear train. A compound configuration for planetary gear train is selected and an optimization study is. In the current literature available to engineers, planetary gear trains are given. Us3021729a planetary transmission for tractors or the like.
The planetary gear trains are commonly used in automotive transmissions. These gear arrangements give different speed ratio options. A variety of representations have been proposed for this type of model. Reliability model for planetary gear trains journal of. Introduction special layouts of simple planetary gear trains composed planetary gear trains elements of planetary gear train design list of symbols skip to article content. Usually, an epicyclical gearing systems are employed to achieve high reduction ratio in a small and power. Planetary gear train a mechanism for transmitting rotational motion by spur or bevel gears less often by. Mechanical analysis gear trains city, university of london. Each planetary gear train only contains three basic links. Compound planetary gear 728 a study on optimization of planetary gear trains 729 tablei planetarygeartraincombinations. Introduction to gear trainsintroduction to gear trains. Epicyclic gearing also called as planetary gearing. The planetary gear sets, or epicyclic gear drives, are commonly used to transform torque and speed in many automotive, aerospace, and marine applications. Free body diagrams of gear trains american society for.
Pdf planetary gear trains pgt have been widely used in many industries due to their unique advantages over parallel shaft gear trains. A lubrication system for a planetary gear train 6 includes oil spray bars 32 intermediate each pair of planet gears 10. Pdf epicyclic drive trains download read online free. Special issue of the 3rd international conference on. Introduction to epicyclic gear train working and advantages. The homotopy analysis for the nonlinear dynamics of planetary. Teaching planetary gear trains with the aid of nomographs. 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. The planet gear are mounted on a moveable arm carrier. Design of machinery an introduction to the synthesis and. The numerical implementation is done within 2dhp90, a twodimensional nite element code, which allows for both h and p adaptation.
A planetary type power transmission comprising an input shaft and an output shaft, a forward planetary gear train and a reverse planetary gear train each having sun, pinion and ring gears in meshing engagement, means to efiect selective driving of said forward and reverse trains by the input shaft, a first carrier for both said trains, first. We use the method introduced in epicyclic ratio calculation trqin determining the final gear ratio of an epicyclic gear train. For an example of automotive applications, most automatic transmissions utilize planetary gear sets for torque or speed multiplications. Intro planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet gear and ring gear. Us5472383a lubrication system for a planetary gear train. The planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. Planetary gear trains is the most comprehensive and uptodate work available in this key technical area. The usefulness of planetary gear trains and the engineering techniques necessary for optimum design are discussed in this paper. It is stated that the simple planetary gear train consisting of two central gears, one or more planet gears and one arm, has 34 different types.
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. Compound planetary gear train planetary gear train with more than one arm r14 t1t3. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. Simple planetary gear trains have a sun gear, a ring, a carrier, and a. Planetary gear train article about planetary gear train by. Planetary gear trains pdf planetary gear trains pdf planetary gear trains pdf download. Next, a parallel, portable code has been developed on a distributed memory machine using mpi. How a planetary gear train functions analogous to solar system. Design, load analysis and optimization of compound epicyclic. Mullers discovery of their perfect analogy to the simple epicyclic drive trains.
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