The mechanical efficiency of epicyclic gear trains. Software gto provides the required results in a very short time. Help me to find this epicyclic gear train nptel pdf gdar excel. Notes on the epicyclic gear train solution techniques with application to tandem bicycling new approach. What is epicyclic gearbox main components, working and. The ratio attained from the gear train depends on the component that has its rotational motion constrained or controlled. Example 6 figure shows a compound epicyclic gear train, gears s1 and s2 being rigidly attached to the shaft q. The book is profusely illustrated and analyzes many applications. 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 definition of epicyclic by the free dictionary. 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.
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. 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. Jan 23, 2015 here is a picture of a typical gear box. Calculate the input and outputs speeds and torques of gear boxes. All the components are modelled in catia to check the assembly and the. Calculate the holding torque on gear box cases it is assumed that the student is already familiar with the following concepts. 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. 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.
In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. Iif the calculated result is negative, the driver and follower will rotate in opposite directions. An epicyclic gear train is a coaxial speed reducer or increaser stage comprised of a sun gear, planet gear s, and a ring gear townsend 1992. A thorough understanding of the sometimes difficult material is facilitated through the use of both schematic and symbolic diagrams. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space. Gear trains theory of machines engineering reference with. 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 volume of the gear train with spur gears is reduced by 22. Problem no 2 on epicyclic gear train gear trains kinematics of machinery theory of machines duration. Apr 16, 2019 problem no 2 on epicyclic gear train gear trains kinematics of machinery theory of machines duration. This design can produce large gear ratios in a small space and are used on a wide range of applications from marine gearboxes to electric screw drivers. 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.
The name epicyclic is derived from the curve traced. Planetary epicyclic gear ratios equations and calculators. Tabular method consider an epicyclic gear train as shown in fig. Thus the conventional gear train is simply a special case of the more complex epicyclic train, in which its arm is held stationary. Note that a zero velocity input to the arm merely makes a conventional train out of the epicyclic train as shown in figure 932a. In this video, we have discussed how to tackle questions related to gear train, how to make the.
Pdf notes on the epicyclic gear train solution techniques with. Having more teeth in mesh, not shifting the load so abruptly, also reduces the noise level. These techniques have been applied to the problem of using an epicyclic gear train as a power coupling in a tandem bicycle. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. Gate problems and solutions of compound gear trains duration. In the first three types of gear trains, the axes of the shafts over which the gears are mounted vear fixed relative to each other.
A twostage planetary gear stage is defined using the program. N is the gears teeth number, the sign depends on the type of gear and, in sequence is for external gears. The following two methods may be used for finding out the velocity ratio of an epicyclic gear train. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. While the bulk of this publication is dedicated to the reproduction of nomographs covering the broad general category of problems dealing with air. Generally, singlestage epicyclic gear trains are more efficient than equivalent parallel shaft gear trains because. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Download limit exceeded you have exceeded your daily download allowance. This accounts for epicyclic gear trains being more quiet than parallel shaft gear trains. This gear has an inner hub c which is fixed to b and in mesh with the fixed ring gear r. Problem no 2 on epicyclic gear train gear trains kinematics of machinery.
Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. Mullers discovery of their perfect analogy to the simple epicyclic drive trains. One is that the bushing needs to be wider to t over the cap on the pinion. In this simple example of an epicyclic train, the only gear left to take an output. Let, ta number of teeth on gear a, and tb number of teeth on gear b. 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. In all cases, if d is known, f 1 d, or, if f is known, d 1 f. Pdf notes on the epicyclic gear train solution techniques. Epicyclic gearing requires a stepbystep process to make it work, and some of the steps are not necessarily intuitive. How a planetary gear train functions analogous to solar system. The epicyclic gear train consists of the sun gear a which is in mesh with the planet gear b. Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train mechanism find, read and.
The gear have more than one gear on the shaft in any epicyclic gear trains, there is called compound epicyclic gear train. Mar 30, 2016 velocity ratios of epicyclic gear train the following two methods may be used for finding out the velocity ratio of an epicyclic gear train. Pdf the mechanical efficiency of epicyclic gear trains. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. As such, this article aims to provide assistance and guidelines for people designing epicyclic gear trains for the first timeand perhaps, if you will, ease their degree of suffering. 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.
Planetary gear system could be used to secure higher gear ratio in compact space. Types of gear train and velocity ratio calculation techminy. 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. 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 act on those parts. 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. Table 1 comparison of parallel shaft vs epicyclic gear trains. These drives receive an unusually clear treatment because at dr. Introduction to gear trainsintroduction to gear trains. What is the advantage and disadvantage of a epicyclic gear. Example for, sun and planet gear is a compound epicyclic gear train. Epicyclic gears by mauro caresta 1 epicyclic gears aim of this note is to explain the direct method to solve problems with epicyclic gears the epicyclic gear first analysed here have the following components. 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. Gear train conguration appendix a8 another interesting design aspect is that the gear train reverts back to the axle about which the pinion turns. The circulation of the spur gear takes place in analogy to the orbiting of the planets in the solar system.
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. Following are the different types of gear trains, depending upon the arrangement of wheels. Describe three types of epicyclic gear boxes solve gear box ratios. The input gear has 20 teeth and the output gear has 100 teeth. 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. 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.
Design of machinery an introduction to the synthesis and. R is the angular speed of the arm, equal to the input angular speed. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. Planetary gear systems have very smalllarge train ratios and are very compact. Pdf epicyclic gear train solution techniques with application to. A gear train is a combination of gears used to transmit motion from one shaft to another.
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