The number of shafts and direction of rotation of the input gear determine the direction of rotation of the output gear in a compound gear train. Motor angular displacement and load angular displacement and their derivatives are related by the gear ratio n. Gears c and b represent a compound gear as they appear fixed together. Pdf gear ratios for compound gear trains of minimum weight. Compound gear train the two middle gears share a common axle, so they rotate at the same speed. On completion of this short tutorial you should be able to do the following. A compound gear train with gears p, q, r and s has number of teeth 20, 40, 15 and 20 respectively. The gear train is classified into following types, simple gear train compound gear train riveted gear train epicyclic gear train 1. Pdf selection of the appropriate reversible twocarrier planetary. With the help of this video you can also guess the topic of your project also i hope you will enjoy the.
Introduction applications types of gear train introduction to compound gear train equation derivation for compound gear train. Use both the tabular and formula methods to determine the output speed of the ring gear 6. R5 model the forces and torques in a gear train as a system of linear equations. After the analysis of existing structures, the new structure that represents the combination of a worm gearing and a compound.
The compound gear train allows you to multiply gear ratios together. One of the most important mechanical components is a gear wheel. Design, load analysis and optimization of compound epicyclic gear trains syed ibrahim dilawer1, md. In gear train, combination of two or gears are used to transmit power. The structure of an epicyclic gear the sun wheel, the planet wheels, the annulus and the spider. Let t1 number of teeth on gear 1, r1 pitch circle radius of gear 1, and n1 speed of gear 1 in r. The objective of the gear train design is to find the number of teeth of the four gears and to obtain a required gear ratio of 16. Simple gear train in this type, there is only one gear is mounted on each shaft. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train.
Simple gear trains schematic of simple gear train a simple gear train is a number of simple gear pairs in series. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Two inputs are needed to obtain a predictable output. Compound gear train when there are more than one gear on a shaft,it is called a compound gear train compound gear train for large velocities ratios, compound gear train arrangement is. Simple gear trains schematic of simple gear train a simple gear train is a number of simple gearpairs in series. The aim of our research has been to perform the synthesis of a new structure of combined gear trains that would feature a very compact construction and a relatively inexpensive manufacturing process as well as very high transmission ratios and good efficiencies.
In a real gear box, power is lost through friction and the power output is smaller than the power input. A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage. Gear b is the output of the first pair and gear c is the input of the second pair. The numbers of the sun gear 2, planet gears 3, 4 and 5, and ring gear 6 are 30, 20, 60, 30 and 200, respectively. Finally, combining these expressions, we arrive at the equilibrium equation for the circuit. Design, load analysis and optimization of compound epicyclic. Why might compound gear trains be better than two gears alone. Gear trains theory of machines engineering reference with. Reverted gear train output shaft is concentric with the input shaft. 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.
In this video you will learn about working of compound gear train with fully explaination. In some epicyclic gear trains, we may find two or more. Two gears fixed together in this way rotate together and at the same rpm. 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 34 45 56 4 23 4 5 34 56. Thus we see that in a reverted gear train, the motion of the first gear and the last gear is like. A network theory for variable epicyclic gear trains technische. Gear trains theory of machines engineering reference.
The gear train below has an arrangement of gear wheels including two compound gears. Simple gear train the most common of the gear train is the gear pair connecting parallel shafts. The compound gear train has two gears on some of the shafts. Deb, k, and goyal, m, optimizing engineering designs using a combined genetic search. They rotate in the same direction and act like one gear. Pdf symbolic computation of planetary gear train efficiency. Hi there using compund gear train, we can have a maximum change in power output comparing to simple one. They are locked on to the common shaft say with a keyway or spline. Gears b and c are locked to the same shaft and revolve at the same speed. Please answer the question below in a detailed man.
When the same direction of rotation is required for the driver and the follower, an idler wheel is used. Mar 01, 2015 final gear ratio compound gear train conclusion 7. The gears 4 and 5 are also compound gears which are mounted on shaft c. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. Use merge points to merge the point the point at the end of the lineofcentres for the first gear pair, and point at the end of the new line. A calculator for designing a multistage compound gear train. In a reverted gear train, the driving and the driven gears are coaxial or coincident. The teeth of this type can be spur, helical or herringbone. A compound gear train is one where a gear is located on a second shaft with another gear which turm in common. Consequently, it is possible to create very large gear ratios and hence generate very large torque and low speeds from highspeed, lowtorque motors. This allows the final gear to rotate slower and produce more torque than if it were connected only to the driver gear. To merge pdfs or just to add a page to a pdf you usually have to buy expensive software. To merge or manage pdf files, youll need either a free but limited thirdparty productivity app or one of a variety of welldesigned commercial apps.
Planetary gear train axes of all gears are fixed axes r. Gear trains like this are often found inside machines such as centre lathes and milling machines. Planetary or epicyclic gear train in simple gear trains, each shaft supports one gear. But stock gears come with certain bore sizes, requiring knowledge of the necessary shaft diameter. In the lever analogy, an entire compound planetary gear train can usually be. Angular velocity ratio between gears must remain constant throughout their mesh. Our servers in the cloud will handle the pdf creation for you once you have combined your files. Automobile gear system engine will constantly produce rotaional force with specific speed an. In some cases, such as the automotive differential, one input is provided the. Apr 28, 2016 introduction applications types of gear train introduction to compound gear train equation derivation for compound gear train.
By joining two shafts of one component planetary gear. The procedure is to start with the input, and to calculate how the angular velocity propagates through each successive intermeshing pair of gears based upon the number of teeth. A simple gear can change magnitude and line of action of an effort force. Simple gear train a simple gear train uses two gears, which. By dragging your pages in the editor area you can rearrange them or delete single pages. Additionally, for the reverted compound gear train, applicability of the solution obtained is evaluated for the special case in which the interstage speed ratios are made equal throughout the. Idler gears are gears used to add spacing between other gears in a gear train. Compound train an intermediate shaft carries two wheels connected in series. 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. In the first three types of gear trains, the axes of the shafts over. Gears are compact, positiveengagement, power transmission elements capable of changing the.
Determining compound gear ratios multiple stages when a gear train has multiple stages, the gear ratio for the overall gearing system is the product of the individual stages. A gear whose axis itself is revolving is called a planetary gear. Also, you can add more pdfs to combine them and merge them into one single document. Works on home computers pc or mac as well as smartphones and tablets. Design, load analysis and optimization of compound. It becomes necessary when it is required to obtain large speed reduction within a small space. 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. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. Provides teeth counts from any given overall ratio. A compound reverted gear train is to be designed as a speed increaser to provide a total increase of speed of exactly 45 to 1. Simple gear train is one in which each shaft carries only one gear.
A compound locomotive is a steam locomotive which is powered by a compound engine, a type of steam engine where steam is expanded in two or more stages. Compound gear train a simple gear train uses two gears, which may be of different sizes. Two and three stages were used in ships, for example compounding became popular for railway locomotives from the early 1880s and by the 1890s were becoming common. The term power transmission is defined as the move ment of. A gear train is a combination of gears used to transmit motion and power from one shaft to another it is also known as train of toothed wheels gear trains may use spur, bevel or spiral gears. Simple gear trains, compound gear trains for large speed reduction, epicyclic gear trains algebraic and tabular methods of finding velocity ratio of epicyclic gea. Pdf this paper considers twospeed planetary gear trains with four external shafts composed of two simple. Illustration from army service corps training on mechanical transport, 1911, fig. Apr 30, 2017 in this video you will learn about working of compound gear train with fully explaination. Apr 04, 2015 reverted gear train are the compound gear train in which both the axis of the driver and the driven shaft are coaxial. Another class of gear train has wide application, the epicyclic or planetary train. Reverted gear train are the compound gear train in which both the axis of the driver and the driven shaft are coaxial. Mar 29, 2020 for high speed reduction, compound gear trains are required.
The gears 4 and 5 are also compound gears which are mounted on shaft c and the gear 6 is the driven gear mounted on shaft d. Compound gear train in this type, two or more gears are. Index terms epicyclic gear train, power split device. The gear 3 which is now the second driver drives the gear 4 i. Compound gear train in a compound gear train at least one of the shafts in the train. The total mechanical loss is then given as the sum of losses from all gear meshes and bearings. The effort force is applied to the driver and the load is applied to the follower. This planetary gear train consists of a sun gear yellow, planet gears blue supported by the. Simple train three or more wheels connected in series. Compound gear trains schematic of compound, threestage, gear train a compound gear train has at least. The analysis of the gear train is relatively simple, but the result may be unexpected. The train in figure has two gears in between the input and output gears. When gears are meshed together, we say we have a gear train.
Previous years gate questions on gear trains 200820. On a smaller scale, plastic gear trains are found inside dvd recorders. 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. Theory of machines gear trains 11 introduction a gear train is a combination of gears used to transmit motion from one shaft to another. Pdf a nonlinear dynamic model for compound planetary gear sets. A reverted gear train is shown in figure given below, it should be noted that gear 1 and the gear 4 are mounted on the driver and the driven shaft respectively, whose axes are collinear.
Publishers pdf, also known as version of record includes final page, issue and volume numbers. For example, for the gear at left the blue gears are 7 and 21 teeth, while the green gears are 9 and 30 teeth. Pdf the determination of the mechanical efficiency of a planetary. Gear q and r are mounted on the same shaft as shown in the figure below. Compound gear trains involve several pairs of meshing gears. The gearing inside this servo is a compound gear train with four stages. When a simple gear train has three meshed gears, the intermediate gear between the driver gear. A nonlinear dynamic model for compound planetary gear sets. R5 combine these linear equations into a matrix equation. Ofcourse,all thegears fixedonto the same shaft rotateat the same rate the rateof rotationof the shaft. Gears c and b are fixed together and rotate in the same direction and at the same speed.
Another example of a compound gear system is seen below. The diameter of the gear q is twice that of gear r. As before, we will use the part that has gear 2 of stage 2, as the part for gear 1 of the stage 3. If one of these gears is attached to a motor or a crank then it is called the driver gear. In this video, we will understand how linear algebra can help us to predict the losses and understand the design tradeoffs when converting high speeds and low torques into low speeds and high torques using a gear train. For this reason, planetary gear trains are also called epicyclic. The locomotive was only one application of compounding. Design of machinery an introduction to the synthesis and. The gear that is turned by the driver gear is called the driven gear. For the gear train shown below, determine the train value, output speed, output direction, output torque, and output power. Simple gear train a simple gear train uses two gears. The arm in driven at 50 rpm cw, and the input speed of the sun gear 2 is 50 rpm ccw.
To obtain the gear ratio, tv output rateinput rate, of a compound gear train, an illustrated example is presented in this section. A compound gear train is to be designed to achieve a specific gear ratio between the driver and driven shafts. Edit the basepart, add a line merge it with the end of the line used for gearpair stage 2, close the parteditor. Usually, gears have the same module throughout a compound gear train. In normal atmospheric conditions, all engineering metallic surfaces are primarily coated with some adsorbed gas fig. Compound gear train for large velocities, compound arrangement is preferred two or more gears may rotate about a single axis. In a compound gear train, each shaft supports two gear wheels except the first and the last.
Compound gear train the two middle gears share a common axle. Following are the different types of gear trains, depending upon the arrangement of wheels. Introduction to gear trainsintroduction to gear trains. Development of a design tool for a twodegree of freedom gear. When drawn with a compass they have the same centre.