Technique for examing epicyclic gear box krish gupta, ajay sharma amity university, aset, noida, india abstract this paper presents a method for analyzing epicyclic gearboxes by evaluating the speeds, torques and efficiency of the external elements in epicyclic gear mechanisms, as well as the total ratios of the gear box. Sign up now to enroll in courses, follow best educators, interact with the community and track your progress. The epicyclic gear trains are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wrist watches etc. 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. Another class of gear train has wide application, the epicyclic or planetary train. 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. Illustrated below is a typical epicyclic gear train. Planetary or epicyclic gear train epicyclic gear train.
This would allow the study of dynamic loading by considering tooth engagement which is affected by characteristics of the gears in mesh, such as errors, tooth stiffnesses, masses of the gears and contact ratios. Notice how the planet gears roll on and revolve about the sun gear. The stresses were also calculated with the help of ansys. The mechanical efficiency of epicyclic gear trains. It can be seen that the gear paircarrier system has two.
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. The tool investigated is from atlas copco st series and consists of three main parts. A spur gear differential is constructed from two identical coaxial epicyclic gear trains assembled with a single carrier such that their planet gears are engaged. The paper gives a general method for determining the assembly condition of epicyclic gears, irrespective of the structure or gear type. 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. A methodology for the design of tworing ravigneauxtype. Software gto provides the required results in a very short time.
Please consider this design as a basis to be customised to your own application. Introduction planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Jul 18, 2017 a gear train is a combination of gears used to transmit motion from one shaft to another. Used to change theused to change the direction of rotation or to connect two shafts at a distance. By using epicyclic gear, different torque speed ratio can be obtained. 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.
Introduction to epicyclic gear train working and advantages and. The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears. The wheels d and e rotate together on a pin fixed to the arm g. These drives receive an unusually clear treatment because at dr. The working principle of the epicyclic gearbox is based on the fact the fixing any of the gears i. Epicyclic gears get their name from their earliest application, which was the modelling of.
Epicyclic gearing also called as planetary gearing. 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. Application of the element relations to a complete train is carried out as shown in the example which follows. Pdf design, load analysis and optimization of compound. The inputand output shaftsare coaxial andthe inputand output 1 torques are assumedto be coaxialwith these shafts. 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. Planetary gear system could be used to secure higher gear ratio in compact space. On completion of this short tutorial you should be able to do the following.
Gear trains theory of machines engineering reference with. Epicyclic gear trains are powerful when used correctly, but are often misunderstood. Following are the different types of gear trains, depending upon the arrangement of wheels. 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. Gear trains theory of machines engineering reference. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. Power acting on the compound epicyclic gear trains is also varied and graphs are plotted to see the load behavior. This was developed as a chart which shows all the favourable conditions for. In this video, we have discussed how to tackle questions related to gear train, how to make the necessary table and reach the desired conclusion. Two inputs are needed to obtain a predictable output. Simple train three or more wheels connected in series.
Analysis of the epicyclic gear train was successfully completed with all its results collected and presented in the form of charts. Simple gear train compound gear train reverted gear train epicyclic gear train 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. The gears must rotate maintaining a fixed ratio of angular velocities relative to the carrier body. Although the working principle of planetary gears has been known for many years. In this case, the ring gear is usually fixed and the sun gear is driven.
Planetary or epicyclic gear train gear train mechanical. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. A thorough understanding of the sometimes difficult material is facilitated through the use of both schematic and symbolic diagrams. 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. Introduction to gear trainsintroduction to gear trains. The following two methods may be used for finding out the velocity ratio of an epicyclic gear train. As fixing any of the above causes the variation in gear ratios from high torque to high speed. A twostage planetary gear stage is defined using the program. Planetary or epicyclic gear train gear train like a compound gear train, planetary trains are used when a large change in speed or power is needed across a small distance. 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. Everything you need to print a complete, printable and full functional epicyclic gearing train. Design of machinery an introduction to the synthesis and.
Pdf design and analysis of an epicyclic gearbox for an. Epicyclic gear train an epicyclic gear train,the axes of the shafts, over which the gears are mounted, may move relative to a fixed axis. A unified approach to the assembly condition of epicyclic. The book is profusely illustrated and analyzes many applications. 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. Recent articles in gear solutions have discussed epicyclic gearing, but often in the context of experienced engineers. The volume of the gear train with spur gears is reduced by 22. Gears are the main component of the transmissions because they play the crucial role of transmitting the power from the input to the output with a defined ratio. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. 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. Using lever analogy diagrams in teaching compound planetary. 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. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3.
Also to be considered would be the influence of the gear train composed. More complex epicyclic trains may be analysed in a similar manner, but the technique is not of much assistance when the problem is one of gear train design the interested designer is referred to the bibliography. Calculate the input and outputs speeds and torques of gear boxes. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other. The epicyclic gear train with bevel gears is used in 1. The planet and sun gears mesh so that their pitch circles roll without slip. What is the advantage and disadvantage of a epicyclic gear. In case there is a third gear there will be 3 trains and then 3 equations. This type of transmission are used by skoda,toyota, lexus, etc epicyclic gearing planetry gearing. The result of this project is a very compact epicyclic gear. In order to achieve the above objective, methodology of design used is explained in next point. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts.
Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train mechanism find. Describe three types of epicyclic gear boxes solve gear box ratios. In fact, my reconstruction of the front dial depends crucially on the observation that the fig. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train. In this lesson, we will study about epicyclic gear trains, planetary gear trains, easy method to solve numerals on epicyclic gear train and holding torque of gears. Epicyclic planetary gear system 3d cad model library. They are great speed variation mechanisms, and are often.
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. A network theory for variable epicyclic gear trains citation for published version apa. In this case, the fundamental formula for the planetary gear train yields. Compound train an intermediate shaft carries two wheels connected in. Simple compound gear train n n n n t t t t r nn nn rr rr 26 tttt 16 15 14 15 14 12 23. In raos treatment cf the epicyclic gear train 4, service load variation isconsideredand both tooth bendingfatigue and pittingfatigue types of failure areaamitted. Epicyclic gear train has two gears so that the center of one gear revolves around the center of the other. Calculate the holding torque on gear box cases it is assumed that the student is already familiar with the following concepts. Pdf epicyclic gear train dynamics including mesh efficiency. The gear b meshes with gear a and has its axis on the arm at o2, about which the gear b can rotate. Tabular superposition method for analyzing of planetary gear trains. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. The planet gear are mounted on a moveable arm carrier. It is a gear system that consists of one or more outer gear planet gear rotating about a central sun gear.
Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. What is epicyclic gearbox main components, working and. The other gears are carried by a carrier which are called planet gears. There are four different ways that a planetary train can be hooked up. Using computer simulation software, such as working model and visual nastran.
According to the method, an associated mechanism is. The plotted graphs can be used to verify the compound epicyclic gear train model for different favorable conditions. The number of teeth on wheels c, d, e and f are 35, 65, 32 and 68 respectively. As more and more of these engineers reach retirement age younger engineers must pick up where they left off, and for many epicyclic gearing is an area where they lack experience. Pdf the mechanical efficiency of epicyclic gear trains. Planetary gear is one of the epicyclic gear, which is a gear system consisting of one or more. To define a train, consider that it has always the arm r, a gear of the planet and a main gear. New design and improvement of planetary gear trains. High pressure angle spur gears for epicyclic gear trains. All 34 types can be derived from one general form of the simple planetary gear train.
Epicyclic gearing requires a stepbystep process to make it work, and some of the steps are not necessarily intuitive. 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. Design of two stage planetary gear train for high reduction ratioprabhakar vitthal pawar. A complete working model was developed in solidworks cad software with all its specifications. Pdf the paper presents an epicyclic gear train dynamic. Design, load analysis and optimization of compound. A compound configuration for planetary gear train is selected and an optimization. A network theory for variable epicyclic gear trains. The planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. Compound train an intermediate shaft carries two wheels connected in series. Design, load analysis and optimization of compound epicyclic. In his masters thesis for virginia polytechnic institute and state university, entitled epicyclic gear train solution techniques with application to tandem bicycling1, christopher corey has. The sign is negative for exterior gears and positive for interior gears. This forms a planetary gear train with a fixed carrier train ratio r.
Table 1 comparison of parallel shaft vs epicyclic gear trains. The useful application of the epicyclic gear train with bevel. This accounts for epicyclic gear trains being more quiet than parallel shaft gear trains. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. Introduction to epicyclic gear train working and advantages. Therefore, in the present stuay, pitting fatigue is tne moae of failure on which the reliability of each component is based.