This transmission system can be screw type or gears type. This book is very useful for learning about gears and gearing. Pdf the paper presents an epicyclic gear train dynamic mathematical model including mesh efficiency, bearingsseals losses and inertial. Types of gears classification of gears types of gear trains. 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. 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. In this article we will discuss how to calculate gear ratio, speed and torque for various gear train. Pdf the mechanical efficiency of epicyclic gear trains.
Example for, sun and planet gear is a compound epicyclic gear train. Gear trains theory of machines engineering reference with. The following two methods may be used for finding out the velocity ratio of an epicyclic gear train. A new methodology for the enumeration of feasible clutching sequences for a given epicyclic gear mechanism egm is presented using the kinematic nomographs of epicyclic type transmission mechanisms. The sun gear, ring gear and planet carrier all rotate about the same axis. Pdf epicyclic gear train dynamics including mesh efficiency.
The schematic of a conventional planetary gear train is shown in fig. 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 planet gears are mounted on shafts that turn in planet carrier and meshes with both the sun gear and the ring gear. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. Gears 4 and 1 are in line, and gears 2 and 3 are on the same shaft. To understand gear ratio we suggest you first read. Interface shear strength in mixed lubrication can be given by. Another class of gear train has wide application, the epicyclic or planetary train. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can rotate. The train will end up being reverted gear 1 and 3 will be in line and gear 2.
Various types of planetary gears have been surveyed and the khv type was recommended as having potential for wider use with medium power. Helical gearing, in which the teeth are cut at an angle with the axis of rotation, was developed after spur gearing and has the advantages that has the smoother action and tends to be trainw fig. Types of gear train and velocity ratio calculation techminy. When there is only one gear fitted on each shaft, then this type of gearing system named simple gear trains. The mechanical efficiency of epicyclic gear trains. Gear train it is defined as two or more gears are made to mesh with each epicyclic gear train the axes of the shafts over which the gears are mounted, may move relative to a fixed axis. Gear surfaces coated with boundary additive or antifriction. Design of machinery an introduction to the synthesis and. 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. They are used to increase or decrease the speed or torque of the output shaft.
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. Types of gear trains following are the different types of gear trains, depending upon the arrangement of wheels. Following are the different types of gear trains, depending upon the arrangement of wheels. When pinion is the driver, it results in step down drive in which nptl output speed. Epicyclic gear systems can achieve high velocity ratios with a small number of gears. Pdf kinematic nomographs of epicyclictype transmission. Apr 25, 2020 gear train it is defined as two or more gears are made to mesh with each epicyclic gear train the axes of the shafts over which the gears are mounted, may move relative to a fixed axis. Design, load analysis and optimization of compound. In this project, we use gear type of transmission system, which is designed depending upon the. Nov 12, 2017 problem no 1 on epicyclic gear trains gear trains kinematics of machinery theory of machines duration. The gear train consists of five external gears and 4 internal annulus gears, including sun and planet gears forming an epicyclic gear train. The ratio attained from the gear train depends on the component that has its rotational motion constrained or controlled. Advantages of planetary gear system planetary gear system has lots of advantage as compared to traditional gearboxes 1. 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.
Each gear train consists of a sun gear in the centre, three planet gears, a planet linkage and an internal or ring gear. 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. Mullers discovery of their perfect analogy to the simple epicyclic drive trains. Problem no 1 on epicyclic gear trains gear trains kinematics of machinery theory of machines duration. Gear trains theory of machines engineering reference. Finally, the ring is the internal gear that meshes with the planets. Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train mechanism find, read and cite all the research you need on. Components, working principle, advantages, disadvantages, and applications pdf by mohammed shafi may 2, 2020 may 8, 2020. Introduction to epicyclic gear train working and advantages. We have generally 4types of gear trains, and those are.
All 34 types can be derived from one general form of the simple planetary gear train. Usually when two gears mate, they rotate opposite to each other. With certain types of compound arrangements ratios of 2000. The following two methods may be used for finding out the velocity ratio of. It is a wellknown fact that one can get 111, velocity ratios of six different values having only one planetary gear train p. A gear train is a combination of gears used to transmit motion from one shaft to another. Introduction to gear trainsintroduction to gear trains. If there is only one gear mounted on each shaft, the gear train is known as simple gear train. Jun 17, 2019 epicyclic gear train nptel pdf merge sijthre. Types of gears gear and its types mechanical gears. As the carrier rotates, planets rotate on planet gear shafts while orbiting the sun. Gear basic theory of machine interview question and answers helical gear advantages,disadvantages and application combination of gearless transmission with rods and epicyclic gear train epicyclic gearbox diagram, working, advantages of epicyclic gearbox gear train types, diagram, design calculation what is gear motor. It is interesting to note that coefficient of friction is variable and it depends on operating conditions.
It is used as a transmission system to get various speed ratios in forward as well as in reverse. Compound train an intermediate shaft carries two wheels connected in series. A differential is a gear train with three shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others, or a fixed multiple of that average. Sep 30, 2012 the types of gear train are given below. 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.
Compound train an intermediate shaft carries two wheels connected in. 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 epicyclic gear trains are used in the back gear of lathe, differential gears of the automobiles, hoists, pulley blocks, wrist watches etc. Two inputs are needed to obtain a predictable output. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. A simple epicyclic or planetary gear train is shown the figure. Epicyclic gear train nptel pdf automatic transmission has not better fuel economy. New design and improvement of planetary gear trains. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. Khk offers for free the gear technical data book in pdf format. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. Compound planetary gears involve one or more of the following three types of structures. 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.
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. One is that the bushing needs to be wider to t over the cap on the pinion. Generally, these are called planetary, star, and solar. The ring gear is stationary and the arm rotates at 1 rpm. 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. What is epicyclic gearbox main components, working and. Simple gear train in this type, there is only one gear is mounted on each shaft. Planetary gear system could be used to secure higher gear ratio in compact space. The gear have more than one gear on the shaft in any epicyclic gear trains, there is called compound epicyclic gear train. Simple train three or more wheels connected in series.
These drives receive an unusually clear treatment because at dr. Notes on the epicyclic gear train solution techniques with application to tandem bicycling new approach. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. The book is profusely illustrated and analyzes many applications. The name epicyclic is derived from the curve traced. In the first three types of gear trains, the axes of the shafts over which the gears are mounted are fixed relative to. In gear train, combination of two or gears are used to transmit power. 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. Pdf notes on the epicyclic gear train solution techniques. Basic gear axis for planetary gear train mechanism. Planetary or epicyclic gear train epicyclic gear train. An epicyclic gear train is a coaxial speed reducer or increaser stage comprised of a sun gear, planet gears, 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. A new methodology for the enumeration of feasible clutching sequences for a given epicyclic gear mechanism egm is presented using the kinematic nomographs.
In epicyclic gear train, different types of gear are used like spur gear, helical gear, bevel gear and many more. All the components are modelled in catia to check the assembly and the. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Here wheel a and arm c have a common axis at o1 about which they can rotate.
Gear ratio is the ratio of output and input number of teeth on a shaft. The gear train is classified into following types, simple gear train compound gear train riveted gear train epicyclic gear train 1. Types of gearbox complete explanation mechanical booster. What is the advantage and disadvantage of a epicyclic gear. Types of gear train simple, compound, reverted, epicyclic. Determine the train ratio for the epicyclic train shown below.
An epicyclic gear train, the axes of the shaft, over which the gears are mounted, move relative to a fixed axis. It is stated that the simple planetary gear train consisting of two central gears, one or more planet gears and one arm, has 34 different types. 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. Epicyclic gearbox is also known as planetary gearbox or planetary gear train or epicyclic gear train. 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 development of new types of planetary and planetary facegear drives is proposed. 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 usually made up of two or more gears. Epicyclic gear systems can be divided into three types.
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