Each gear train consists of a sun gear in the centre, three planet gears, a planet linkage and an internal or ring gear. Having more teeth in mesh, not shifting the load so abruptly, also reduces the noise level. The outermost gear, the ring gear, meshes with each of the planet gears. In discussing the spur gear differential, the use of the term annular gear is a convenient way to distinguish the sun gears of the two epicyclic gear trains. The bevel gear train shown is called humpages reduction gear. Epicyclic gear trains consist of two or more gears mounted so that the center of one gear. This apparatus consists of two standard epicyclic gear trains. Mar 30, 2016 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. The advantage of epicyclic gear train is that, it can get very high or very low velocity ratio compared to simple gear trains and compound gear trains. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. 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. Planetary gear trains pdf planetary gear is one of the epicyclic gear, which is a gear system consisting of.
The epicyclic gear trains, or planetary gear trains, are important in the automatic transmissions. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train. With mechdesigner, it is epicycluc to design any number of mechanisms and cams in one model, then analyze, scrutinize and optimize all of them together, so that you can get the best machine performance. Thus, formulae 7 and 9, valid for the ordinary, can be extended to the elementary gear trains with epicyclic arrangement. A pgt has been represented by its functional schematic, structural and kinematic graph. Gear trains image from simon fraser university image from jtekt torsen na, inc. Types of gear train and velocity ratio calculation techminy. The epicyclic gear arrangement is reduced to an ordinary gear train by means of a kinematic inversion which makes. Epicyclic gear train free download as powerpoint presentation. 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. R is the angular speed of the arm, equal to the input angular speed. 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. However, advances in internal gear manufacturing did not parallel those in external gears, limiting the development of epicyclic gear trains. Bevelgear epicyclic trains are used quite frequently and their analysis may be carried out as spur gear epicyclic trains.
An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. Pdf epicyclic drive trains download read online free. A carrier connects the center 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. 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 sun gear, ring gear and planet carrier all rotate about the same axis. Proc instn melh fngrs vol 197c the first group involves the use of epicyclic type gear trains which are either heavier than used in fig. Us8376902b2 epicyclic gear system with flexpins and. The epicyclic gear trains are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wrist watches etc.
Gear ratio product of driven teethproduct of driving teeth gear ratio 100 x 100 x 100 20 x 40 x 10 125 alternatively we can say there are three simple gear trains and work ot the ratio for each. Design of machinery an introduction to the synthesis and. To define a train, consider that it has always the arm r, a gear of the planet and a main gear. With four core components, calculating the gear ratio of planetary gear systems, also known as epicyclic gear systems, may seem daunting. Having more teeth in mesh, not shifting the load so abruptly, also reduces. In epicyclic gear train, different types of gear are used like spur gear, helical gear, bevel gear and many more. Planetary gear train a planetary transmission system or epicyclic system as it is. 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. Scribd is the worlds largest social reading and publishing site. All the components are modelled in catia to check the assembly and the. Types of gear train simple, compound, reverted, epicyclic. What is the advantage and disadvantage of a epicyclic gear. The gear system also includes a carrier 8 having an end wall 12 and flexpins 20 cantilevered from the end wall and extended into the planet pinions.
Design, load analysis and optimization of compound epicyclic gear trains syed ibrahim dilawer1, md. Epicyclic gears get their name from their earliest application, which was the modelling of the movements of the planets in the heavens. In the case of epicyclic gearing, at least one of the gears not only rotates about its own axis but also rotates about some other axes. Epicyclic drive trains wayne state university press. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears.
The planet gears are mounted on shafts that turn in planet carrier and meshes with both. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. The gear have more than one gear on the shaft in any epicyclic gear trains, there is called compound epicyclic gear train. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can rotate. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. In this case, the ring gear is usually fixed and the sun gear is driven. A thorough understanding of the sometimes difficult material is. Ring gear i t is a type of gear which looks like a ring and have angular cut teethes at its inner surface,and is placed in outermost position in en epicyclic gearbox, the inner teethes of ring gear is in constant mesh at outer point with the set of planetary gears,it is also known as annular ring. 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. A planetary or epicyclical gear trains comprises of one or more planet gears revolving around a sun gear.
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. A thorough understanding of the sometimes difficult material is facilitated through the use of both schematic and symbolic diagrams. Jun 12, 2016 hey guys here i have solve this an example of epicyclic gear train in medical in a very simplified form so that you can understand it much better and can apply the same concept to every problem. We propose hereafter a unified model of epicyclic gear trains, based on a primitive parametric kernel, which contains all usual gear train formulations of any compound gear train. Planetary gear trains are one of the main subdivisions of the simple epicyclic. Design, load analysis and optimization of compound epicyclic. 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. Mullers discovery of their perfect analogy to the simple epicyclic drive trains. A planetary or epicyclic gear train is one type of gear train used to transmit motion. This is a comprehensive text and reference book for students and teachers of mechanical engineering, for design and research engineers, and for manufacturers and users of gear trains for the transmission of power in industry and transportation. In these gear trains, one or more gears are carried on a rotating planet carrier rather than on a shaft that rotates on a fixed axis.
These drives receive an unusually clear treatment because at dr. 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. Pdf a unified theory of epicyclic gear trains yves. Generally, singlestage epicyclic gear trains are more efficient than equivalent parallel shaft gear trains because. All 34 types can be derived from one general form of the simple planetary gear train.
Epicyclic gearing also called as planetary gearing. Us3473416a us3473416da us3473416a us 3473416 a us3473416 a us 3473416a us 3473416d a us3473416d a us 3473416da us 3473416 a us3473416 a us 3473416a authority us united states prior art keywords sun gear epicyclic pinions gear train prior art date 19650420 legal status the legal status is an. Gear trains of the type shown in figures 1, 3, 4 and 5 are called epicyclic gear trains or planetary gear trains. Epicyclic gear train overdrives are so arranged that the input shaft drives the pinion.
Each flexpin at its end remote from the end wall carries a sleeve 22. As previously stated, the human powered vehicle team at virginia tech has in the past considered planetary gear trains as a viable means of. Dynamics of transmissions using epicyclic gear trains. Introduction to gear trainsintroduction to gear trains. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. Design, load analysis and optimization of compound. Design and load analysis of and optimization of compound. The gear train maybe for spur gear, helical gear and spiral gear.
We show that the nested and the ravigneaux gear train derive from a. A frequent application of epicyclic gear trains is accomplishing a large speed reduction in a small space. Plane t a r y gear tra i n s consis t o f the follo w i n g. What is epicyclic gearbox main components, working and. Planetary gear drive of high reduction ratios, clutches, etc.
Example for, sun and planet gear is a compound epicyclic gear train. It require small area during the power transmission and to obtain large speed reduction. Two inputs are needed to obtain a predictable output. As industrial applications required transmissions with higher power ratings, the performance of epicyclic gear systems became poorer at higher loads since. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space. The dualwheel transmission dwt, proposed elsewhere using epicyclic gear trains egts, is designed here with epicyclic trains of cams and rollers. Describe three types of epicyclic gear boxes solve gear box ratios.
N r1 and n s1 n r2 and n s2 are teeth numbers for ring and sun gear at planetary gear 1 planetary gear 2, respectively. Introduction to epicyclic gear train working and advantages. In this paper, graph theory is used for the study of epicyclic gear trains or planet gear trains e. Dynamics of transmissions using epicyclic gear trains 20010903 due to the current changes in the automotive industry several new technologies are being developed and the old ones analyzed. An epicyclic gear train consists of two gears mounted so that the centre of one gear revolves the fundamental formula of the planetary gear train with a rotating carrier is obtained by recognizing that. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. These were then generalized to epicyclic gear trains with nonparallel shafts in later works for applications in. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. Another class of gear train has wide application, the epicyclic or planetary train. It will be extremely useful to american engineers since it stresses the efficiencies of new and existing transmission designs and provides concise guide rules as well as worksheets. A gear train is a combination of gears used to transmit motion from one shaft to another. The mechanical efficiency of epicyclic gear trains. Epicyclic gearbox diagram, working, advantages of epicyclic gearbox epicyclic gearbox.
Jul 11, 2015 applications the epicyclic gear trains are useful for transmitting high velocity ratios with gears of moderate size in a comparatively lesser space. A gear train is two or more gear working together by meshing their teeth and turning. Epicyclic planetary gear box 3d cad model library grabcad. The gear wheel transmitted motion between one shaft to another shaft, so the multiple set of gear transmit motion from single main gear to various revolving parts is known as gear train. The epicyclic gear first analysed here have the following components. Calculate the input and outputs speeds and torques of gear boxes. Pdf kinematic and dynamic simulation of epicyclic gear. Help me to find this epicyclic gear train nptel pdf gdar excel. Pdf the mechanical efficiency of epicyclic gear trains. 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. Epicyclic gear trains synthesis, analysis and applications. This accounts for epicyclic gear trains being more quiet than parallel shaft gear trains. The book is profusely illustrated and analyzes many applications. In ordinary gearing, the axes of various gears are fixed.
Planetary gear system could be used to secure higher gear ratio in compact space. Following are the different types of gear trains, depending upon the arrangement of wheels. Apr 08, 2019 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. Software gto provides the required results in a very short time. The volume of the gear train with spur gears is reduced by 22. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Calculate the holding torque on gear box cases it is assumed that the student is already familiar with the following concepts. Apr 25, 2020 introduction to gear trainsintroduction to gear trains. Pdf a unified theory of epicyclic gear trains yves remond. The second sun gear serves the same purpose as the annular gear of a simple planetary gear train, but clearly does not have the internal gear mate that is typical of an annular gear. Design study of kw helicopter transmission with split.