Reverted gear train pdf

A portion of these are basic criteria for the design of gear. In a gear train when the axis of the first and the last gear coincide or coaxial is. Kinematics of gear trains conventional gear trains. Since the motion of the first and last wheel is alike, therefore a compound wheel is provided. A reverted gear train has the first and last gears as. Ordinary gear trains have axes, relative to the frame, for all gears comprising the train. A gearbox is to be designed with a compound reverted. Solutions to chapter 10 exercise problems problem 10. The speed and direction of gear c when gear b is fixed and the arm amakes 100 rpm. These types of gear trains are used widely in automobile manual transmission systems. Gear b meshes with gear e and gear c meshes with gear d. Jan 11, 2018 a reverted gear train is very similar to a compound gear train. Variable gear train is a compound gear train, which has a variable gear reduction ratio. Sometimes, two or more gears are made to mesh with each other to transmit power from one shaft to another.

Jan 01, 20 kinematics of gear trains conventional gear trains. They could also be used to change the axis of input and ou. Sep 20, 2017 compound gear trains are those which have more than one gear on the same shaft. In the first three types of gear trains, the axes of the shafts over which the gears are mounted. Introduction to gear trainsintroduction to gear trains. For simple gear train, compound gear train and reverted gear train axes of motion of wheel are fixed in position and gears rotate about their. Gear trains theory of machines engineering reference. When the axes of the first gear and the last gear are coaxial, then the gear train is known as reverted gear train as shown in figure.

It is a compound gear with, two gearspairs, and a special condition that makes the total number of teeth of the first gear pair equals the number of teeth of the second gear pair, when the module is the same. Consequently, the dimensions of the sun gear would be onethird of the pinion of a parallel shaft geartrain designed to transmit an equivalent torque. The image to the left shows a schematic of a reverted geartrain. The gear 3 which is now the second driver drives the gear 4 i. Such a combination is called gear train or train of toothed wheels types of gear trains following are the different types of gear trains, depending upon the arrangement of wheels.

Reverted gear train applications of reverted gear train. In a reverted epicyclic gear train, arm a carries two gears b and c and a compound gear d e. It is a compound gear with, two gearspairs, and a special condition that makes the total number of teeth of the first gearpair equals the number of teeth of the secondgearpair, when the module is the same. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis.

The train will end up being reverted gear 1 and 3 will be in line and gear 2. All the gears have been manufactured with a normalized rack with a reference pressure angle of 20. Types of gear train and velocity ratio calculation techminy. The input gear has 20 teeth and the output gear has 100 teeth.

Unit iv epicyclic gear boxes home sri venkateswara. The output should deliver the power at a rotational speed in the range of 280 to 300 revmin. Figure 76a shows a simple ordinary train in which there is only one gear for each axis. Types of gear trains depend upon the arrangement of wheels. A calculator for designing a multistage compound gear train. Types of gears classification of gears types of gear trains. A simple reverted gear train consists of two shafts each of which carry multiple compound spur 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. The gear train in the figure has a transmission ratio of 3 between the input gear 1 and the output gear 3 and comprises of three gears. The gear b meshes with gear eand the gear c meshes with gear d. A gearbox is to be designed with a compound reverted gear train that transmits 25 horsepower with an input speed of 2500 revmin. Apr 04, 20 reverted gear train when the axes of the first gear i. Epicyclic gear trains are known to provide high power density and have. So reverted gear train may be called as a compund gear train but all compound gear train can not be a reverted gear train. Types of gear train simple, compound, reverted, epicyclic. Riveted gear train gear ratio is calculated similar to compound gear train. Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train.

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. Gear train synthesis or design is the process of selecting the design parameters in a gear train system to meet desired objectives. Reverted gear train as shown in figure, when gear 1 and 2 are rotate in opposite direction. A simple gear train with idler is a gear train the contains 3 gears. Compound epicyclic gear train sun and planet wheel. This type of arrangement is used in clocks and in simple lathe where back gears are. What is the difference between compound gear train and. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. They are both used when there is only a small space between the input and output shafts and large changes in speed or power are needed.

A gear train is a combination of gears used to transmit motion from one shaft to another. Some are listed in the bibliography at the end of this chapter. Jan 17, 2018 problem no 2 on epicyclic gear train gear trains kinematics of machinery theory of machines duration. Sep 25, 2017 in this lecture i have discussed about the numerical problem on reverted gear train from theory of machines in hindi.

In this lecture i have discussed about the numerical problem on reverted gear train from theory of machines in hindi. Gear train, modification, gear ratio, direction, spur gear. The image to the left shows a schematic of a reverted gear train. Gears 1 and 2 have z 1 12 teeth and z 2 35 teeth, respectively. See the above two pictures to understand how the gear reduction ratio can vary from 1. Determine the length of the contact line and the contact ratio. Following are the different types of gear trains, depending upon the arrangement of wheels. But in simple reverted gear train the direction of rotation of input and output shaft is same. These gears are called the driver, idler, and driven or follower. Planetary or epicyclic gear train epicyclic gear train.

Since the distance between the centres of the shaft 1 and 2 as well as 3 and 4 is the same. The epicyclic gear train is useful for transmitting highvelocity ratio with a gear of moderate size and in less space. Reverted gear train when the axes of the first gear i. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can rotate. This type of arrangement is used in clocks and in simple lathe where back gears are used to give a slow speed to the chuck. If the axes of driver shaft and driven shaft is coaxial, then the gear train is termed as reverted gear train. Compound gear trains are those which have more than one gear on the same shaft.

They are both used when there is only a small space between the input and output. Find the speed and direction of gear c when gear b is fixed and arm a makes 100 rpm cw. Reverted gear is use in compound gear train which is a difference between simple gear train and reverted gear train. Compound reverted gear design project by obadah yaghi on prezi. Examples of the use of these devices will be presented as well. The idler merely changes the direction of the follower so. The variable gear train is often coupled with a clutch. They are used to achieve high gear ratio within limited space. Types of gear trains asimple gear train bcompound gear. In this example, gear1 and gear3 are on the same axis. The reciprocal of the speed ratio or velocity is known as train value. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. What are application of reverted gear train answers.

For the gear train shown below, determine the train value, output speed, output direction, output torque, and output power. When two or more gears are made to mesh with each other to transmit power from one shaft to another, such a combination is called gear train or train of toothed wheels. Thus we see that in a reverted gear train, the motion of the first gear and the last gear is like. Spur gears with 20 pressure angle are used, with 16 teeth on each of the small gears and 48 teeth on each of the larger gears. Mechanical analysis gear trains city, university of london. Works on home computers pc or mac as well as smartphones and tablets.

In the case of the reverted gear train, the driver and the last gear are coaxial. Reverted gear trains are a type of compound gear trains in which input and output shafts are on the same axis. In this lesson, we will study about epicyclic gear trains, planetary gear trains, easy method to solve numerals on epicyclic gear train and holding torque of gears. The number of teeth on gears b, c and d are 75, 30 and 90respectively. Design of machinery an introduction to the synthesis and. Problem no 2 on epicyclic gear train gear trains kinematics of machinery theory of machines duration. Types of gear trains in 1,2,3 the axes of the shafts over which the gears are mounted are fixed relative to each other. The first and last gear are mounted on same axis of rotation in shaft is known as reverted gear trains. Reverted gear train pdf following are the different types of gear trains, depending upon the arrangement of wheels.

In figure 76b a compound ordinary train is seen to be one in which two or more gears may rotate about a single axis. The velocity ratio of an epicyclic gear train is determined by the following methods. In a gear train when the axis of the first and the last gear coincide or coaxial is known as reverted gear train. An automotive gear differential is a jointfractionated planetary gear train with two degreesoffreedom. A reverted gear train is very similar to a compound gear train. Reverted gear has two or more rigidly fixed gears of different size and has different number of teeth on the same shaft with same axis of rotation and same angular velocity. There are two major differences between compound and reverted gear trains. When the axes of the first and last wheels are coaxial the train is known as reverted gear trains as shown fig. Provides teeth counts from any given overall ratio. Pdf minimisation of the overall weight of the reverted and the nonreverted compound gear trains of arbitrary number of stages are formulated as. Note that the common normal is, in fact, the strings of both involutes. In this example, gear 1 and gear 3 are on the same axis.

The gear b meshes with gear e and the gear c meshes with gear d. A gearbox is to be designed with a compound reverted gear. This chapter will discuss the kinematics of gear tooth theory, gear types, and the kinematic design of gearsets and gear trains of simple, compound, reverted, and epicyclic types. It should be pointed out that six planets do not necessarily give a gearing twice the capacity of a similar. The number of teeth on gears b, c and d are 75, 30 and 90 respectively. Compound gear trains allows to achieve higher gear ratios without having the need for more number of shafts.