In case there is a third gear there will be 3 trains and then 3 equations. Apr 04, 20 epicyclic gear train in an epicyclic gear train, the axes of the shafts, over which the gears are mounted, may move relative to a fixed axis. 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. Another class of gear train has wide application, the epicyclic or planetary train.
Epicyclic gear train free download as powerpoint presentation. What is the advantage and disadvantage of a epicyclic gear. Ppt gear trains powerpoint presentation free to view id. This accounts for epicyclic gear trains being more quiet than parallel shaft gear trains. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. 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. Applications the epicyclic gear trains are useful for transmitting high velocity ratios with gears of moderate size in a comparatively lesser. A simple epicyclic or planetary gear train is shown the figure. Ring or annular gear ring gear is the biggest gear in terms of size in whole geartrain. The first element comprises the external sun gear 1 and planet 2.
Epicyclic gear train the axes of the shafts, over which the gears are mounted, may move relative to a fixed axis. An epicyclic train consists of two threecomponent elements of the kind examined above. In the solar system the planets revolve around the sun. Epicyclic gear train it is the system of epicyclic gears in which at least one wheel axis itself revolves around another fixed axis. Definition of epicyclic gear train in the dictionary. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. Gear trains theory of machines engineering reference. Types of gear train and velocity ratio calculation techminy. An epicyclic gear, also referred to as a planetary gear, is a gearing system in which gears known as planetary gears revolve around one central gear referred to as the sun gear. Gear b meshes with gear c and revolves around it when the arm is rotated. The planet gear are mounted on a moveable arm carrier.
Epicyclic gear trains are powerful when used correctly, but are often misunderstood. What is epicyclic gearbox main components, working and. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. A gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical system to another, with some gear ratio performing a mechanical advantage. The name epicyclic is derived from the curve traced. Parts in a epicyclic gearbox sun gear the sun gear is a gear located at the centre of the whole setup and is always meshed with the planetary gears. In this train, the blue gear has six times the diameter of the yellow gear.
A bearer associates the focuses of the two gears and turns to convey one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. R is the angular speed of the arm, equal to the input angular speed. Two inputs are needed to obtain a predictable output. Planetary or epicyclic gear train epicyclic gear train. Design, load analysis and optimization of compound epicyclic. An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of a fixed, outer gear ring, or ring gear, sometimes called an annular gear.
Each element consists of the three components illustrated below. Epicyclic gear train a small gear at the center called the sun, several medium sized gears called the planets and a large external gear called the ring gear. Following are the different types of gear trains, depending upon the arrangement of wheels. Best epicyclic gear train in mechanical engineering. The useful application of the epicyclic gear train with bevel gears is found in humpages speed reduction gear and differential gear of an automobile. Dec 05, 2017 an epicyclic gearbox is an automatic type gearbox in which parallel shafts and gears arrangement from manual gear box are replaced with more compact and more reliable sun and planetary type of gears arrangement and also the manual clutch from manual power train is replaced with hydro coupled clutch or torque convertor which in turn made the. This system is reminiscent of the planets orbits around the sun, thus giving the gear system its name. If the shaft p rotates at rpm clockwise, while the annular a2 is driven in counter clockwise direction at 500 rpm, determine the speed and direction of rotation of shaft q. The epicyclic gear trains are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wrist watches etc. The main applications of epicyclic bevel gear train are humpages speed reduction gear and differential gear of an automobile.
A gear train is a combination of gears used to transmit motion from one shaft to another. Information and translations of epicyclic gear train in the most comprehensive dictionary definitions resource on the web. A planetary gear train is a little more complex than other types of gear trains. 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.
Ref willis r, principles of mechanism, cambridge university press, 1841, art. Here wheel a and arm c have a common axis at o1 about which they can rotate. The following two methods may be used for finding out the velocity ratio of an epicyclic gear train. Planetary or epicyclic gear train gear train mechanical. The gear train maybe for spur gear, helical gear and spiral gear.
Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. 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. Gear trains theory of machines engineering reference with. An epicyclic train is often suitable when a large torquespeed ratio is required in a compact envelope. The following 72 files are in this category, out of 72 total.
It is made up of a number of elements which are interconnected to form the train. Planetary gear system could be used to secure higher gear ratio in compact space. Jul 01, 2019 an epicyclic gear train otherwise called planetary gear comprises of two gears mounted with the goal that the focal point of one gear spins around the focal point of the other. The differential gear used in the rear drive of an automobile can be functioned as. Like a compound gear train, planetary trains are used when a large change in speed or power is needed across a small distance. For large velocities, compound arrangement is preferred. The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears. The planet and sun gears mesh so that their pitch circles roll.
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. 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. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. Notice how the planet gears roll on and revolve about the sun gear.
The bevel gears are used to make a more compact epicyclic system and they permit a very high speed reduction with few gears. The bevel gears helps to make the very compact epicyclic system, which can be used in high speed reduction with few gears. Ppt gear powerpoint presentation free to download id. Ppt gear trains powerpoint presentation free to view. Epicyclic gear train epicyclic means one gear revolving upon and around another. A gear is a component within a transmission device that transmits rotational force to another gear or. A planetary gear train is very much like our own solar system, and thats how it gets its name. It require small area during the power transmission and to obtain large speed reduction.
In this investigation is presented a systematic approach for the modelling and analysis of power split transmissions which include an epicyclic gear train, in various configurations, as they are. Epicyclic bevel gear train play ppt ppt presentation summary. Epicyclic gear train definition of epicyclic gear train. It is a gear system that consists of one or more outer gear planet gear rotating about a central sun gear. The humpages speed reduction gear was originally designed as a substitute for back gearing of a lathe, but its use is now considerably extended to all kinds. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. Having more teeth in mesh, not shifting the load so abruptly, also reduces. The outermost gear, the ring gear, meshes with each of the planet gears. 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. The input gear has 20 teeth and the output gear has 100 teeth.
Govindaraju,ssec 30 epicyclic gear train basic theory the diagram shows a gear b on the end of an arm. A thorough understanding of the sometimes difficult material is. Types of gears classification of gears types of gear trains. Pdf the mechanical efficiency of epicyclic gear trains. Design of machinery an introduction to the synthesis and. The design involves planet and sun gears as one orbits the other like a planet around the sun. Design, load analysis and optimization of compound.
Epicyclic gearing also called as planetary gearing. The working of the above gears are mentioned in the below ppt. The planet gears are held to a cage or carrier that fixes the planets in there orbit relative to each other. 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. Planetary epicyclic gear ratios equations and calculators. It acts as a drum or a case for all the others gears. An epicyclic gear train otherwise called planetary gear comprises of two gears mounted with the goal that the focal point of one gear spins around the focal point of the other. To define a train, consider that it has always the arm r, a gear of the planet and a main gear. Gears 4 4 epicyclic gear train epicyclic means one gear revolving upon and around another. Introduction to epicyclic gear train working and advantages. Introduction to gear trainsintroduction to gear trains. Example 6 figure shows a compound epicyclic gear train, gears s1 and s2 being rigidly attached to the shaft q. 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. In a planetary train at least one of the gears must revolve around another gear in the gear train.
The following two methods may be used for finding out the velocity ratio of. Such a gear configuration has useful applications, but the overall gear ratio. An epicyclic gear train, the axes of the shaft, over which the gears are mounted, move relative to a fixed axis. Epicyclic gear train in an epicyclic gear train, the axes of the shafts, over which the gears are mounted, may move relative to a fixed axis. 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. 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. The equations in question are not given, however they almost immediately fall out of willis derivations. In this case, the curve traced by a point on the pitch circle of the planet is a hypocycloid. This is sometimes referred to as conepulley backgearing because of its use within the cone pulleys of certain types of machine tools. A gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical system to another, with some gear ratio performing a mechanical advantage 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 key facts. Illustrated below is a typical epicyclic gear train.
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