The maag design utilizes carburized and ground spur gears. Types of gear train and velocity ratio calculation techminy. Each of the speed ratios available to a simple planetary gear train can be. Planetary kinematics note that point 1 on the planet gear is stationary zero velocity due to noslip assumption note that point 2 on the planet gear has the same velocity as point 2 on the sun gear also due to noslip assumption, which is given by.
An epicyclic train consists of two threecomponent elements of the kind examined above. The planetary gearbox design is fairly simple, consisting of a central sun gear, an outer ring also referred to as an internal gear, because its tooth face inward, planetary gears, and a carrier. Pdf design and analysis of an epicyclic gearbox for an electric. Planetary gear is one of the pdfill image writer epicyclic gear, which is a gear system consisting of. Technique for examing epicyclic gear box krish gupta, ajay sharma amity university, aset, noida, india abstract this paper presents a method for analyzing epicyclic gearboxes by evaluating the speeds, torques and efficiency of the external elements in epicyclic gear mechanisms, as well as the total ratios of the gear box. A geareddown motor must turn farther and faster in order to produce the same output movement in the 3d printerand that is a good thing. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. As the carrier rotates, planets rotate on planet gear shafts while orbiting the sun. Ring gear i t is a type of gear which looks like a ring and have angular cut teethes at its inner surface,and is placed in outermost position in en epicyclic gearbox, the inner teethes of ring gear is in constant mesh at outer point with the set of planetary gears,it is also known as annular ring. 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 basic of epicyclic gear is that it has an sun gear, planetary gears and ring gears this type of gear mechanism is used in the pto shaft of the tractors a.
A gear train is a combination of gears used to transmit motion from one shaft to another. Planetary epicyclic gear ratios equations and calculators. Epicyclic gearing planetary gearboxes in an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference run between a gear with internal teeth and a gear with external teeth on a concentric orbit. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. Oct 20, 2011 example solution for a single stage epicyclic gear.
We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. The sun is the center gear, meshing with the planets, while the carrier houses the planet gear shaft. Motion periods of planet gear fault meshing behavior mdpi. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can rotate. The working of epicyclic gear box can not be explained briefly as it requires more study. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. You need to define the elements role in the gear train, input, output or fixed. This makes them lighter and more compact, versus countershaft gearboxes. A friend and i decided on making a 3d printable planetary gear to test if the idea was fully possible to model into a somewhat modular design that allows for simple assembly and standalone use. All about epicyclic gearing this video illustrates. Set the number of planets and the dynamic parameters as speed and torque of the input element. The first element comprises the external sun gear 1 and planet 2. Jul 06, 2019 blake flournoy is a writer, reporter, and researcher based out of baltimore, md.
Publishers pdf, also known as version of record includes final page, issue and volume numbers. Abstract it has been said that deriving the formulas for the ratios between the various gears of an epicyclic planetary gear system is nonintuitive and taxes the human intellect to say the least. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. A question that i often get is how to work out planetary gears using the gear template generator working out the tooth counts for planetary gears is actually not that complicated, so i initially neglected to mention how to do it. Part of diplomadegree in engineering, new zealand nz. In a reverted epicyclic gear train, arm a carries two gears b and c and a compound gear d e. Pdf this article summarizes published journal articles on planetary and epicyclic gear dynamics and. The epicyclic gear train with bevel gears is used in 1. A question that i often get is how to work out planetary gears using the gear template generator. Spur gear teeth produce no axial force on the geared elements. In ptolemaic cosmology, a small circle, the center of which moves on the circumference of a larger circle at whose center is the earth and the circumference of which describes the orbit of one of the planets around the earth.
This is more likely due to a lack of writing on the subject, rather. The gear train maybe for spur gear, helical gear and spiral gear. Tabular method for epicyclic gear trains tabular method for epicyclic gear trains theory of machines video tutorial theory of machines video tutorials for gate, ies, and other psus exams preparation and to help mechanical engineering students covering. For example, if the sun gear has 20 teeth and the ring gear has 60, the planetary gear has 80 teeth. One of the planetary gearsets from our transmission has a ring gear with 72 teeth and a sun gear with 30 teeth. Each of these three components can be the input, the output or can be held stationary. Designing compound epicyclic gear trains for maximum speed at high velocity ratios, machine design, april 4, 1957. Epicyclic gear calculations pdf with four core components, calculating the gear ratio of planetary gear systems, also known as epicyclic gear systems, may seem daunting. Internet searches for how to proved fruitless and dare i say information is being withheld, so this programmer set out to demystify the methods for calculating the widely used equations of. White western gear corporation, california, ca 917491040 u. The angular speed of the planet carrier can be found since we know the. Introduction to gear trainsintroduction to gear trains. Mechanical efficiency is an important index of gearing, especially for epicyclic gearing. Epicyclic gear train, output torque, holding torque.
An epicyclic differential is at the heart of the toyota prius automotive drive train, where it interconnects the engine, motorgenerators, and the drive wheels which have a second differential for splitting torque as usual. All the components are modelled in catia to check the assembly and the. 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 systems also incorporate the use of an outer ring gear or annulus, which meshes. Jun 12, 2016 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. Planetary or epicyclic gear train epicyclic gear train. The circulation of the spur gear takes place in analogy to the orbiting of the planets in the solar system.
The three basic components of the epicyclic gear are. This is extremely important to optimize the load distribution in the meshing of the planets. A planet in red with 2 gears, gp1 and gp2 1 arm r in green 3 main gears g1, g2 and g3 in blue colour that are in contact with the gears of the planet. A gear train is usually made up of two or more gears. Following are the different types of gear trains, depending upon the arrangement of wheels. The thesis starts with a theoretical chapter containing the fundamentals of epicyclic gearing and the build of the specific gearbox investigated. The design of the gear teeth also affects the relative position of one gear to another. A twostage planetary gear stage is defined using the program. The number of teeth on gears b, c and d are 75, 30 and 90 respectively. The middle portion of such planet gears has a different profile than those on the ends, and is engaged with the rotating ring gear.
Mesh phasing relationships in planetary and epicyclic gears article pdf available in journal of mechanical design 1262 march 2004 with 2,334 reads how we measure reads. Pdf this paper focusses on the designing and optimizing of a planetary gearbox for an fsae formula electric car. Efficiency of epicyclic gears in automated manual transmission systems 20072409 vehicles with automated manual transmissions amt for gear shift control offer many advantages in terms of reduction of fuel consumption and improvement of driving comfort and shifting quality. Design validation of high speed ratio epicyclic gear.
For an epicyclic planetary stage with singular planet gears where the ring gear is stationary, the practical gear ratio varies from 3. Abstract this paper presents a method for analyzing epicyclic gearboxes by evaluating the speeds, torques and efficiency of the external elements in epicyclic gear mechanisms, as well as the total ratios of the gear box. Two forms of planetary gears of the bevel type are shown in figures 23 and 24. The annulus gear has internal teeth and the compound gear is.
Figure 1 below shows a simplified diagram of a planetary geartrain. At this point, the planetary gear train disappears from history for quite some time. Example 6 figure shows a compound epicyclic gear train, gears s1 and s2 being rigidly attached to the shaft q. 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 app will return a valuable information about the geartrain, including the factorization. Also, when configured properly, epicyclic gear sets are more efficient. This results in a low power to weight ratio and, together with lower pitch line velocity, leads to improved efficiency. It require small area during the power transmission and to obtain large speed reduction. Generally, these are called planetary, star, and solar arrangements. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis.
Jul, 2017 the working of epicyclic gear box can not be explained briefly as it requires more study. The final product of the effort, shown above, was des. Planetary gear ratio calculations this article also available in spanish. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space. Norton gives the general equation for epicyclic angular velocity to be. Epicyclic gear example solution for gear ratio youtube.
Design of two stage planetary gear trains for reduction ratio 78. By the way it is technically possible to follow the api rules of the special purpose gear units for petroleum, chemical and gas industry services, also for an epicyclic gearbox. A planetary gearbox offers high torque transmission with good stiffness and low noise, in a more compact footprint than other gearbox types. After the theory is explained the next chapter contains. Calculate gear ratio by dividing the number of teeth on the driven gear by the number of teeth on the driving gear. Find the speed and direction of gear c when gear b is fixed and arm a makes 100 rpm clockwise.
Choosing which piece plays which role determines the gear ratio for the gearset. Planetary gear systems have very smalllarge train ratios and are very compact. 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. Introduction to epicyclic gear train working and advantages. How a planetary gear train functions analogous to solar system. 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. 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 arrangement in figure 4c has common planet gears engaged with the sun gear, two stationary ring gears, and one rotating ring gear.
An epicyclic differential can use epicyclic gearing to split and apportion torque asymmetrically between the front and rear axles. Gear trains theory of machines engineering reference with. Most spur could not carry as much load as slowerrunning gears, gear tooth profiles are cut to conform to an involute highstrength alloy steels for gearing were developed curve in order to ensure conjugate action. Elec tric mo to r gt1 gt2 scre w driv er sh af t sw itc h mo t o r sha f t t em. Each of the speed ratios available to a simple planetary gear train can be obtained by using band brakes to fear and release the carrier, sun or ring gears as needed. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. Nov 25, 2015 this application is able to calculate the motion relation, torque distribution and cycle counting of an epicyclic gear train. Mesh phasing relationships in planetary and epicyclic gears.
In this paper, graph theory is used for the study of epicyclic gear trains or planet gear trains e. Design and optimization of planetary gears considering all. The following chapter contains former testing and theory of power losses in a gearbox. In an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference run between a gear with internal teeth and a gear with external teeth on a concentric orbit. If the carrier is acting as the input in the planetary gear system, rotating the ring gear while the sun gear is still, divide the number of teeth on the ring gear the driven gear by the number of teeth on the planetary gears the driving gears. The planets 2 and 3 are compounded together on the common arm axles. Working out the tooth counts for planetary gears is actually not that complicated, so i initially neglected to mention how to do it. How does epicyclic gear work some application of epicyclic gear how to make epicyclic gear calcula. This investigationisprimarily concerned with planetary gear drives fig. 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. 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. Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Mar 30, 2016 epicyclic gear train with bevel gear the bevel gears are used to make a more compact epicyclic system and they permit a very high speed reduction with few gears. Advantages of an epicyclic gear artec machine systems.
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. Design of machinery an introduction to the synthesis and. Problem no 1 on epicyclic gear trains gear trains kinematics of machinery theory of machines duration. This example shows an epicyclic gear drive with overall ratio of 256. The gear ratio in an epicyclic gearing system can be different by the design of the gear teeth and the ways of input rotation to the gear. What are the drawbacks to using a planetary gearbox. Epicyclic gear train definition of epicyclic gear train by. Because of its compact size, light weight, the capability of a high speed ratio, and the ability to provide differential action, epicyclic gearing is very versatile, and its use is increasing. Epicyclic definition of epicyclic by the free dictionary. 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. Another class of gear train has wide application, the epicyclic or planetary train.
Magic of mechanics epicyclic planetary gear youtube. Botman 12, who did not write the governing equations in. This investigation is primarily concerned with planetary gear. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. A network theory for variable epicyclic gear trains technische. Pdf the mechanical efficiency of epicyclic gear trains. Epicyclic gear sets are used because they are smaller than offset gear sets since the load is shared among the planed gears. 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. This system is reminiscent of the planets orbits around the sun, thus giving the gear system its name. Intro planetary gears also refer as epicyclic gearing consisting three elements sun.
Recent articles in gear solutions have discussed epicyclic. In this regard, manmade machinery provides us a rich yet more. Mathematics a circle whose circumference rolls along the circumference of a fixed. A pgt has been represented by its functional schematic, structural and kinematic graph. In contrary, humandesigned gearing systems are versatile, ranging from simple, compound, reverted, to epicyclic gear trains 33. It is the case of the gear presented in this paper, which can be considered full api6 compliant.
What is epicyclic gearbox main components, working and. Multiply all above reading by x and write same in second row. I which have a fixed annulus with the planet carrier rotating in the same direction as the sun gear. Highspeed epicyclic gears can be built relatively small as the power is distributed over several meshes. The thesis starts with a theoretical chapter containing the fundamentals of epicyclic gearing and the build of the. Calculate the number if teeth required in the ring gear for the ratio 5. Sun gear i t is the gear with angular cut teethes and is placed in the middle of the. Blake flournoy is a writer, reporter, and researcher based out of baltimore, md. The next steps depend on the state of the planetary gears connected to the carrier, although all use the same formula.
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