Pdf dynamic analysis of epicyclic gear trains by means of. For this example, let the input be the sun gear, the output be the arm, and let the ring be fixed. 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. By fixing one of the coaxial members and using the remaining two for input and output, three types of simple singlestage epicyclic gearing are possible. Each element consists of the three components illustrated below. Each one is positioned so the sun gear engages and turns all. The user enters the revolutions per minute and driection of the first driver. The first element comprises the external sun gear 1 and planet 2. The design involves planet and sun gears as one orbits the other like a planet around the sun. The teeth of this type can be spur, helical or herringbone. Simple gear train compound gear train planetary gear train. To define a train, consider that it has always the arm r, a gear of the planet and a main gear.
Gear c compound epicyclic gear trainsun and planet gear in an epicyclic gear train, as shown in figure, the wheel c is keyed to the shaft b and wheel f is keyed to shaft a. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Planetary gear system could be used to secure higher gear ratio in compact space. Introduction to gear trainsintroduction to gear trains. Download limit exceeded you have exceeded your daily download allowance. 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 last is a reduction again, but the output direction is reversed. Each one is positioned so the sun gear engages and turns all the planetary gears at once. A carrier connects the centers of the two gears and rotates to carry one gear, called the planet gear, around the other, called the sun gear. Take velocities of the extreme gears in the train relative to the carrier write the equation for the ratio of the two gears using the chain rule solution methodology. Looking for downloadable 3d printing models, designs, and cad files. Epicyclic gear trains are powerful when used correctly, but are often misunderstood. 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. The stationary gear sun gear or ring gear can be referred to as the central gear.
Also, locking any two of the three components together will lock up the whole device at a 1. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. Information and translations of epicyclic train in the most comprehensive dictionary definitions resource on the web. Example 6 figure shows a compound epicyclic gear train, gears s1 and s2 being rigidly attached to the shaft q. The number of teeth on wheels c, d, e and f are 35, 65, 32 and 68 respectively. Gears gears, gear trains and gear box presented by ujjwal nagda 2. The main applications of epicyclic bevel gear train are humpages speed reduction gear and differential gear of an automobile. R is the angular speed of the arm, equal to the input angular speed. The planet and sun gears mesh so that their pitch circles roll without slip. This presentation is very useful for the subject theory of machine, topic. Jun 11, 2016 here you will find a detailed description and introduction of epicyclic planetry gear train. 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 gear b meshes with gear a and has its axis on the arm at o2, about which the gear b can rotate. If a simple gear train or compound gear train is attached to the epicyclic gear train, do not include it in the analysis and treat it as part of a separate simple gear train. For a simple gear train, we do not need one of the gears in the stage 2 gearpair. Design of machinery an introduction to the synthesis and. Thus we see that in a reverted gear train, the motion of the first gear and the last gear is like. Information and translations of epicyclic gear train in the most comprehensive dictionary definitions resource on the web. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other. The annulus gear has internal teeth and the compound gear is carried by the arm and revolves freely on a pin of the arm h. 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.
Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. Advantages and velocity ratio of epicyclic gear train. Pdf dynamic analysis of epicyclic gear trains by means. 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.
Write down the relative velocity equations on the lhs 4. What is the advantage and disadvantage of a epicyclic gear. Another class of gear train has wide application, the epicyclic or planetary train. Right an example of an epicyclic gear sketch lecture. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. In this lecture i have discussed about the numerical problem on simple epicyclic gear train from theory of machines in hindi.
Let t1 number of teeth on gear 1, r1 pitch circle radius of gear 1, and n1 speed of gear 1 in r. For the first installment, weve focused on agmas online and video training programs. An epicyclic train consists of two threecomponent elements of the kind examined above. 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. Epicyclic train article about epicyclic train by the free. Epicyclic gear train apparatus manufacturer supplier india. Epicyclic gear train epicyclic means one gear revolving upon and around another. Ppt types of gear trains powerpoint presentation, free download. As before, the fast gear is the sun gear and slow gear is the ring. For large velocities, compound arrangement is preferred. Planetary epicyclic gear ratios equations and calculators. Pdf the mechanical efficiency of epicyclic gear trains. Gear power transmission is the movement of energy from its place of generation to a location where it is applied to performing useful work a gear is a component within a transmission device that transmits rotational force to another gear or device. Ppt automobile gearbox powerpoint presentation free to.
Power flow and efficiency analysis of epicyclic gear. Highspeed epicyclic gears can be built relatively small as the power is distributed over several meshes. The most common of the gear train is the gear pair connecting parallel shafts. Illustrated below is a typical epicyclic gear train. O e of the prime and biggest use of a planetary gearbox is for running the armature of a wind turbine. Find the number of teeth on all gears use geometry 2. It is a motorized unit consisting of a sun gear mounted on input shaft. Ppt gear powerpoint presentation free to download id. This is made possible in a 3 or more planet arrangement. This results in a low power to weight ratio and, together with lower pitch line velocity, leads to improved efficiency.
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. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Epicyclic gears planetary gears from maagrenkmaag have been used in plants with fastrunning turbo machines for over 50 years. Gear trains theory of machines engineering reference. Epicyclic gear train the axes of the shafts, over which the gears are mounted, may move relative to a fixed axis. There would be numerous applications of planetary gearbox, but i will anser with the one which im sure about. It is made up of a number of elements which are interconnected to form the train. The working of the above gears are mentioned in the below ppt. Designing compound epicyclic gear trains for maximum speed at high. Sep 18, 2017 hi all online lectures for engineering students. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. Epicyclic gearing overal gear ratio calculator fx solver.
The gear 3 which is now the second driver drives the gear 4 i. Epicyclic train article about epicyclic train by the. The second is an overdrive the output speed is faster than the input speed. A thorough understanding of the sometimes difficult material is. 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. This example shows an epicyclic gear drive with overall ratio of 256. A basic example is a singlestage gear unit withthree fixedplanets and a rotating carrier know as a star epicyclic gear. Definition of epicyclic gear train in the dictionary. The first is the center gear, known as the sun gear. Gear trains theory of machines engineering reference with.
Theory of machines is an applied science of the relationships between geometry and relative motion of the parts of the machine, and concerns to the forces which. Epicyclic gear train free download as powerpoint presentation. 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. The term power transmission is defined as the move ment of. In the numerical of simple epicyclic gear train i have found out or calculated the speed. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the. Mar 30, 2016 compound epicyclic gear train sun and planet gear. 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. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Epicyclic gear train solution techniques with application.
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. 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 epicyclic gear trains, the axes of shafts on which the gears are mounted may move relative to a fixed axis. 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. Notice that the first gear ratio listed above is a reduction the output speed is slower than the input speed. Two inputs are needed to obtain a predictable output. Designing compound epicyclic gear trains for maximum speed at high velocity ratios, machine design, april 4, 1957. Advantages of an epicyclic gear artec machine systems. If the basic efficiency is 95%, what is the efficiency of the planetary gearset in driving the load.
This gear turns all the gears around it and is at the very center of the entire gear system. Gear train is a new gear technology section focusing on training and education in the gear industry. One of the most important considerations for an epicyclic gear is to assure uniform load distribution among the planets. This is sometimes referred to as conepulley backgearing because of its use within the cone pulleys of certain types of machine tools. An epicyclic train is often suitable when a large torquespeed ratio is required in a compact envelope. Epicyclic gear train gear machines free 30day trial. Gear train is any combination of gear wheels by which motion is transmitted from one shaft to another shaft. It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. An epicyclic gearbox consists of two, three or even four epicyclic or planetary gear sets. Gear trains image from simon fraser university image from jtekt torsen na, inc. Such a gear configuration has useful applications, but the overall gear ratio. 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. Notice how the planet gears roll on and revolve about the sun gear.
Various gear position are marked on the gear lever knob itself. The bevel gears helps to make the very compact epicyclic system, which can be used in high speed reduction with few gears. Epicyclic gear train solution techniques with application to. Right an example of an epicyclic gear sketch lecture outline. In the numerical of simple epicyclic gear train i have found out or calculated. A combination of epicyclic gears, usually connected by an arm, in which some or all of the gears have a motion compounded of rotation about an axis and a. Epicyclic gear trains have broad applications in automobile, aerospace, mill, and automation industries, such as.
Find the fixed gear if any and substitute a value of zero for its angular velocity 5. In case there is a third gear there will be 3 trains and then 3 equations. A simple gear set has a sun gear, about which planets turns round. 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 load on the arm is 50 lbfin and the sun spins at 100rpm. The mechanical efficiency of epicyclic gear trains. Geartrain calculates the angular velocity of the final driven gear in a gear chain.