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. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. It is a gear system that consists of one or more outer gear planet gear rotating about a central sun gear. On completion of this short tutorial you should be able to do the following. Epicyclic gear train solution techniques with application. The paper illustrates the application of a systematic technique for thededuction of dynamic equations of epicyclic gear trains. A fixedring epicyclic gear train is required to have an overall ratio of 5. The term power transmission is defined as the move ment of. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. Components, working principle, advantages, disadvantages, and applications pdf by mohammed shafi may 2, 2020 may 8, 2020 epicyclic gearbox is also known as planetary gearbox or planetary gear train or epicyclic gear train. Suppose an epicyclic gear train has 2 gears gear a and gear b and an arm arm c. Design, load analysis and optimization of compound.
Gear trains often consist of multiple gears in the train, as shown in the following two figures. Other uses for gears how gear ratios work howstuffworks. Introduction to epicyclic gear train working and advantages. For a more involved epicyclic gear train example, please refer to the epicyclic gear train example section. The owner would like your company to manufacture a shop display that is eye catching for passers. Epicyclic gear train we have already discussed that in an epicyclic gear train, the axes of the shafts, over which the gears are mounted, may move. The planet gear are mounted on a moveable arm carrier. Gears are compact, positiveengagement, power transmission elements capable of changing the amount of. 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. The input gear has 20 teeth and the output gear has 100 teeth. Simple gear trains schematic of simple gear train a simple gear train is a number of simple gearpairs in series. But in case of epicyclic gear trains, the axes of the shafts on which the gears are mounted may move relative to a.
Specifically, this thesis will provide a simple solution technique for the general case of a twodegree of freedom 2dof planetary gear train along with new graphical design aids. The inputand output shaftsare coaxial andthe inputand output 1 torques are assumedto be coaxialwith these shafts. Planetary gears are common in transmission systems, where they provide high gear ratios in compact geometries. A carrier connected to a drive shaft holds the planet gears. 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. If the arm is the input and the planet is the output, the overall gear ratio is 31 3. The second is an overdrive the output speed is faster than the input speed. With the rotation of each element of the gear train in hand, the overall gear ratio becomes easy. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. Epicyclic gearing also called as planetary gearing. Gear d 400 rpm 20 teeth output against a load of 200 nm all shafts carry a frictional resistance of 5 nm i need to find. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. Pdf dynamic analysis of epicyclic gear trains by means. The last is a reduction again, but the output direction is reversed.
The epicyclic gear train family in general has a central sun gear which meshes with and is surrounded by planet gears. It consists of two coaxial shafts s1 and s2, an annulus gear a which is fixed, the compound gear bc, the sun geard and the arm h. Pdf the mechanical efficiency of epicyclic gear trains. 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 worm gear can achieve a higher gear ratio than spur gears of a comparable size. A substantial amount of literature is available for planar linkages.
Gear trains theory of machines engineering reference. A twostage planetary gear stage is defined using the program. In this paper, graph theory is used for the study of epicyclic gear trains or planet gear trains e. Epicyclic gear trains have been broadly applied in engineering practice. Balance shaft and gear train modeling to capture gear. Thediscussed examples illustrate how the presented approach can be extendedfor computing the equivalent inertia. This chapter will explore the theory of gear tooth action and. To create large gear ratio, gears are connected together to form gear trains.
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. A worm gear is a gear in which a wheel resembles a screw, with parallel helical teeth, while the other is like a normal spur wheel. A gear train is a combination of gears used to transmit motion from one shaft to another. Also, locking any two of the three components together will lock up the whole device at a 1. A network theory for variable epicyclic gear trains. Epicyclic gear train gear machines free 30day trial. 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. Gear train with sun, planet, and ring gears matlab. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space.
It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. Ordinary gear trains have axes, relative to the frame, for all gears comprising the train. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. All three are attached to a plate the planet carrier, and they engage the inside of the blue gear the ring instead of the outside. Simplified gear train system modeled in gt suite v6. For this analysis, we consider a gear train that has one. 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. In gear train, combination of two or gears are used to transmit power. What is epicyclic gearbox main components, working and. Freudenstein i in 1955, gave an appropriate but a numerical method for dimensional synthesis of a four bar linkage. Simple gear train efficiency and torque help physics forums. Design of machinery an introduction to the synthesis and.
Based on the number of degrees of freed om, the epicyclic gear trains can be further categorized as differential and planetary gear trains. One or more sun gears can be used for achieving different output. Compound gear train in this type, two or more gears are. Introduction to gear trainsintroduction to gear trains. Plane t a r y gear tra i n s consis t o f the follo w i n g. This is the same convention as used in automotive transmissions. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the. The epicyclic gear trains may be simple or compound.
All the components are modelled in catia to check the assembly and the. Due to the high speed and torque ratios and compact and effective structure planetary gear train systems are widely used in many fields. Epicyclic gear trains are known to provide high power density and have become the gear train of choice for the main power flow in virtually all rotorcraft designs. Im working on a solution to this problem and i would like some advice and help. Planetary gear is one of the epicyclic gear, which is a gear system consisting of one or more outer gears. Planet gears t hese are small gears used in between ring and sun gear, the teethes of the planet gears are in constant mesh with the sun and the ring gear at both the inner and outer points respectively.
The use of theproposed method is particularly amenable in conjuction with proceduresfor the computerized enumeration of geared kinematic chains. Each element consists of the three components illustrated below. Following are the different types of gear trains, depending upon the arrangement of wheels. Not only the epicyclic gear trains in common uses were obtained, but some new types of epicyclic gear trains. Internal gear train operates in the same gear direction. The method of the innovative synthesis of the epicyclic gear trains was presented. A presentation on epicycle gear train linkedin slideshare. Simple gear train in this type, there is only one gear is mounted on each shaft. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. Consider a motor driving a rotary load through a gear train, as shown in figure 1. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. An epicyclic train is often suitable when a large torquespeed ratio is required in a compact envelope. Notice that the first gear ratio listed above is a reduction the output speed is slower than the input speed. The epicyclic gear trains are useful for transmitting high velocity.
The axis of the planet gears are attached to the planet carrier which is carrying the output shaft of the epicyclic gearbox. The mechanical efficiency of epicyclic gear trains. 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. 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.
The stationary gear sun gear or ring gear can be referred to as the central gear. For the gear train shown below, determine the train value, output speed, output direction, output torque, and output power. Dynamic analysis of epicyclic gear trains by means of. In this gear system, the yellow gear the sun engages all three red gears the planets simultaneously. The gear train is classified into following types, simple gear train compound gear train riveted gear train epicyclic gear train 1.
The outermost gear, the ring gear, meshes with each of the planet gears. Whenever a change in the speed or torque of a rotating device is needed, a gear train or one of its cousins, the belt or chain drive mechanism, will usually be used. Experimental analyses of vibration and noise of faulted. The planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering.
Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. The annulus gear has internal teeth and the compound gear is. A small gear and a larger gear are connected together, one on top of the other. What is the advantage and disadvantage of a epicyclic gear. So the absolute speed of a gear is the relative speed with respect to the shaft plus the shafts speed with respect to ground. A pgt has been represented by its functional schematic, structural and kinematic graph.
A thorough understanding of the sometimes difficult material is. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. Thus a gear train is a set or system of gears arranged to transfer rotational torque from one part of a mechanical system to another. The angular position of the motor is given by m, while the angular position of the load is given by l. 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. The righthand purple gear in the train is actually made in two parts, as shown. This block models a gear train with sun, planet, and ring gears. Gear trains are widely used in all kinds of mechanisms and machines, from can openers to aircraft carriers.
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