Introduction to gear trainsintroduction to gear trains. It is made up of a number of elements which are interconnected to form the train. The planet and sun gears mesh so that their pitch circles roll. A fixedring epicyclic gear train is required to have an overall ratio of 5. In simple, compound and reverted gear train, gear shaft axis is fixed or not movable but in epicyclic gear trains, the shaft axes are not fixed means the shaft axis is movable. If the ring gear f is fixed, determine the angular velocities at gears a, b, and c. The planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. Consolidating fissile materials in russias nuclear complex.
A simple gear train has only one gear fixed to each shaft. Let t1 number of teeth on gear 1, r1 pitch circle radius of gear 1, and n1 speed of gear 1 in r. The paper illustrates the application of a systematic technique for thededuction of dynamic equations of epicyclic gear trains. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray.
The three basic components of the epicyclic gear are. 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. 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. It may be regarded as a set of four rigid bodies because. An idea for coupling two engines to drive a generating. Definition of epicyclic gear train in the dictionary. Definition of gear train from the collins english dictionary. Machinedesign com sites machinedesign com files uploads 2015 02 gears1 1. The ring gear 5 is fixed and the gear 2 is rotating at 60 rpn ccw ccwcounterclockwise and cw clockwise. Compound epicyclic gear trains compound epicyclic gear trains.
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. 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. These drives receive an unusually clear treatment because at dr. Publishers pdf, also known as version of record includes final page, issue and. In this simple example of an epicyclic train, the only gear left to take an output.
The obtained optimal forcedisplacement curves result in decelerations in the passenger areas, which are below 5g. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Thediscussed examples illustrate how the presented approach can be extendedfor computing the equivalent inertia of an epicyclic gear train or forthe stability analysis of 2 d. Based on the number of degrees of freed om, the epicyclic gear trains can be further categorized as differential and planetary gear trains. Development of motorassisted hybrid traction system. Development of motorassisted hybrid traction system 1h. 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.
Induction motors, converter control, traction, simulation introduction currently, most suburban trains in russia contain 2 head carriage, 5 6 motor carriage and 3 4 auxiliary carriage. Each element consists of the three components illustrated below. Annulus an outer ring with inwardfacing teeth that mesh with the. In line with clients variegated requirements, we bring forth a distinguished collection of epicyclic gear train apparatus. Compound train an intermediate shaft carries two wheels connected in. How many times will gear a rotate compared to gear dq how does this compare to the gear ratio you just calculated in the table.
A thorough understanding of the sometimes difficult material is facilitated through the use of both schematic and symbolic diagrams. Automobile gear system engine will constantly produce rotaional force with specific speed an. Structural crashworthiness of railway vehicles manuel s. An epicyclic gear train is shown schematically in the adjacent figure. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. Note that a zero velocity input to the arm merely makes a conventional train out of the epicyclic train as shown in figure 932a. 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. Most of this material is a legacy of the cold war, when the soviet union and the united states each created nuclear. In this regard, manmade machinery provides us a rich yet more.
In the first three types of gear trains, axes of shafts over which the gears are mounted are fixed relative to each other 112320. Motion analysis allison compound epicyclic geartrain. The gear b meshes with gear a and has its axis on the arm at o2, about which the gear b can rotate. Simple train three or more wheels connected in series. Following are the different types of gear trains, depending upon the arrangement of wheels. The epicyclic gear train consists of the sun gear a which is in mesh with the planet gear b. Pdf design, load analysis and optimization of compound. 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. Thus the conventional gear train is simply a special case of the more complex epicyclic train, in which its arm is held stationary.
Mech 314 dynamics of mechanisms april 16, 2011 planetary gear train velocities 1 planetary gears and pitch point gear velocities figure 1. Genetic approach for multiobjective optimization of epicyclical gear. The gear 3 which is now the second driver drives the gear 4 i. Thus we see that in a reverted gear train, the motion of the first gear and the last gear is like. So the absolute speed of a gear is the relative speed with respect to the shaft plus the shafts speed with respect to ground. Planetary gears, which can supply a lot of speed reduction and torque in a small. Experimental analyses of vibration and noise of faulted. The sun gear2 on the input shaft is a 20 teeth external gear. Im working on a solution to this problem and i would like some advice and help. It is a compound gear with, two gearspairs, and a special condition that makes the total number of teeth of the first gearpair equals the number of teeth of the secondgearpair, when the module is the same. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Dynamic analysis of epicyclic gear trains by means of. An alternative method for kinematic and power analysis of compound gear train is studied, which uses the torques and lever analogy of a given gear.
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. Epicyclic gear train apparatus, mechanical laboratory. R is the angular speed of the arm, equal to the input angular speed. Calculate the holding torque on gear box cases it is assumed that the student is. Alternative method for analysis of complex compound planetary gear trains. The planet gears are held to a cage or carrier that fixes the planets in orbit relative to each other. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other. 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. When gears are meshed together, we say we have a gear train figure1.
Design of machinery an introduction to the synthesis and. Compound planetary trains can easily be configured so the planet carrier. Describe three types of epicyclic gear boxes solve gear box ratios. Hi there using compund gear train, we can have a maximum change in power output comparing to simple one. The outermost gear, the ring gear, meshes with each of the planet gears. If the sun gear is to have between 10 to 15 teeth, suggest the most appropriate numbers of teeth for each of the constituent gears. The book is profusely illustrated and analyzes many applications. Internal ringgear, three planets on spiderarm and the sun gear as semipictorial fig. Types of gear train and velocity ratio calculation techminy. Gears canbe used tochange the speedor directionofa turningmotion,as well as theamount of turningforce,or torque, that is available. In contrary, humandesigned gearing systems are versatile, ranging from simple, compound, reverted, to epicyclic gear trains 33. Types of gear train simple, compound, reverted, epicyclic.
Gear trains theory of machines engineering reference. Thus suburban train consists from 10 or 12 carriages. A network theory for variable epicyclic gear trains technische. Previous years gate questions on gear trains 200820. Pdf the mechanical efficiency of epicyclic gear trains. Helical gear the teeth on helical gears are cut at an angle to the face of the gear this gradual engagement makes helical gears operate much more smoothly and quietly than spur gears one interesting thing about helical gears is that if the angles of the gear teeth are correct, they can be mounted on perpendicular shafts, adjusting the rotation angle by 90 degrees. An epicyclic train is often suitable when a large torquespeed ratio is required in a compact envelope. Motorassisted hybrid traction system the motorassisted ma hybrid system, as shown in fig. The gear have more than one gear on the shaft in any epicyclic gear trains, there is called compound epicyclic gear train. Epicyclic gear train experiment 2229 words bartleby. In the first three types of gear trains, the axes of the shafts over. This apparatus is manufactured at our ultramodern manufacturing unit using the superb quality rawmaterial and progressive technology in conformance with defined quality standards. Table 1 comparison of parallel shaft vs epicyclic gear trains.
In epicyclic gear trains there is relative motion between axes which useful to transmit very high velocity ratio with gears of smaller sizes in lesser. Design, load analysis and optimization of compound. Example for, sun and planet gear is a compound epicyclic gear train. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point.
By multiplying the gear ratios between each set, you discover the ratio between gears a and d. A carrier connects the centres 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. The gear train comprises of gears 7, 4, 3, and 6, with 7 as the first gear and 6 as the last gear. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. The determination of optimal design of the planetary gear train with a lightweight, a short center distance, and a high efficiency is an important issue in the. Calculate the input and outputs speeds and torques of gear boxes.
Epicyclic gear trains may consist of simple gear trains, compound gear trains and mixed simple and compound gear trains. Sort by date 1 design unit evaluating new software from smt januaryfebruary 2007. Planet carrier holds one or more peripheral planet gears, same size, meshed with the sun gear. 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.
The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears. Examples of the use of these devices will be presented as well. Information and translations of epicyclic gear train in the most comprehensive dictionary definitions resource on the web. 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.
Kinematic analysis of synchromesh, machine tool gear box, differential gear box self study 3. But in case of epicyclic gear trains, the axes of the shafts on which the gears are mounted may move relative to a. Hi i require to design an epicyclic gear train which has two different inputs and one output at another gear. When two gears are meshed together properly, turning one gear will turn the other in the opposite direction. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space.
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