The planet and sun gears mesh so that their pitch circles roll without slip. Epicyclic definition of epicyclic by the free dictionary. The working of epicyclic gear box can not be explained briefly as it requires more study. Design of machinery an introduction to the synthesis and. Also, when configured properly, epicyclic gear sets are more efficient. 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. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Traditional gears rely on a small number of contact points between two gears to transfer the driving force. Table 1 comparison of parallel shaft vs epicyclic gear trains. All the components are modelled in catia to check the assembly and the. Developing the gear ratio formula sae international. 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. Developing the gear ratio formula build knowledge introduction what students do in this activity in this activity students make observations about the rotation relationships in the tables they made during the recording gear rotations activity.
Design and analysis of an epicyclic gearbox for an electric. Epicyclic planetary gear system 3d cad model library. Epicyclictrain dynamometertorque and power transmitted auth with social network. Pdf this paper focusses on the designing and optimizing of a planetary gearbox for an fsae formula electric car. The first is the center gear, known as the sun gear. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves around the center of the other. If dia a dia b then for one rotation of a a point on the surface of a would move through a distance equal to 2 x pi x ra. You will now rotate the outer ring gear by that amount to align it correctly with the planet gears. Hypoid gears are based on rolling hyperboloids of revolution as shown in figure 923. Following are the different types of gear trains, depending upon the arrangement of wheels. Large speed reductions are possible with eppicyclic gears and if the fixed wheel is annular, a more compact unit could. All other applications, including machines that run for more than 4 hr but change direction, are considered cyclical. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes with the planet gears.
The following chapter contains former testing and theory of power losses in a gearbox. 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. In some epicyclic gear trains, we may find two or more. 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. Pdf design and analysis of an epicyclic gearbox for an electric.
A planetary gearbox design calculations filetype displays safety factors and life expectation as function of. Application examples planetary gears framo morat usa. After the theory is explained the next chapter contains. An epicyclic gear train also known as planetary gear consists of two gears mounted so that the centre of one gear revolves around the centre of the other. 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. 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. 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.
Planetary gear is one of the epicyclic gear, which is a gear system consisting of one or more outer gears, or planet gears, revolving about a central, or sun gear. Spur gear teeth produce no axial force on the geared elements. This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it. Gear generator is a tool for creating involute spur gears and download them in svg format. The thesis starts with a theoretical chapter containing the fundamentals of epicyclic gearing and the build of the specific gearbox investigated. A generic power flow model for compound epicyclic fourspeed gears is presented.
If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of. Designing compound epicyclic gear trains for maximum speed at high velocity ratios, machine design, april 4, 1957. But the gearing has been specifically designed so that the epicyclic table e3 turns at the rate of rotation of the moons apogeethe factor 53 being. The circulation of the spur gear takes place in analogy to the orbiting of the planets in the solar system. 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. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. It has been documented that epicyclic gear stages provide high load capacity and compactness to gear drives. This investigationisprimarily concerned with planetary gear drives fig. They explore these relationships as constant values that depend on the number of teeth on the two gears. The maag design utilizes carburized and ground spur gears.
Recently, amt are proposed to be connected with epicyclic gears and friction brakes, in order to reduce t. R is the angular speed of the arm, equal to the input angular speed. The system is used by automatic transmission vehicles to switch between gears automatically. The epicyclic gear train with bevel gears is used in 1. Generic power split modelling for compound epicyclic four. This paper will focus on analysis and design of epicyclic gear arrangements that provide extremely high gear ratios. Design, load analysis and optimization of compound epicyclic gear trains article pdf available october 20 with 1,104 reads how we measure reads. 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 geaar are mounted, may move relative to a fixed axis. 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. All these factors increase the cost of this type of gear drive. In addition it let you compose full gear layouts with connetcted gears to design multiple gears system with control of the inputoutput ratio and rotation speed. This planetary gear train consists of a sun gear yellow, planet gears blue supported by the. On completion of this short tutorial you should be able to do the following. This example shows an epicyclic gear drive with overall ratio of 256.
Gears b and c are locked to the same shaft and revolve at the same speed. Generally, these are called planetary, star, and solar arrangements. If there npetl more than one arm in the planetary gear train. Epicyclic gearing arrangements are comprised of four. An epicylic gear is a planetary gear arrangement consisting of one or more planet epicyclic gears p meshed planetary gearbox design calculations filetype rotating round a central sun gear s. Gear generator is a tool for creating involute spur gears and download them in dxf or svg format. The conveyors are driven forward by means of the friction between the drum motor and the belt. In a compound epicyclic gear train as shown pdfinancialcorp com in the figure, has gears. Advantages of an epicyclic gear artec machine systems. Epicyclic gear trains are generally used for automatic transmission, overdrives, and final drives.
But the small gap between gear teeth leads to lost motion. An early use of the sun gearplanet pinioninternal gear type of epicyclic train for. Carriers are simply cages for the planet alignment and location. At this point, the outer ring gear should look correctly sized to mesh with the planet gears, however, the angle of the gear is off by half a gear tooth, or. The motion of helical gears is smoother and quieter than the motion of spur gears. Figure 2 differentialplanetary gear actuators with compound planet gears. 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. 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. We use the method introduced in epicyclic ratio calculation trqin determining the final gear ratio of an epicyclic gear train. Planetary gears are an indispensable element in drum motors for conveyor belts and rollers. This is extremely important to optimize the load distribution in the meshing of the planets. Examples of differentialplanetary gear actuators with compound planet gears are shown in figure 2.
A carrier connects the centres 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. Table 1 maximum gear ratio values for differentialplanetary arrangements with compound planet gears. I which have a fixed annulus with the planet carrier rotating in the same direction as the sun gear. Mathematics a circle whose circumference rolls along the circumference of a fixed. Get epicyclic gear train problems and solutions pdf file for free from our online library created date. Sun 10 teeth planet 14 teeth ring gear stationary 38 teeth ring gear output 41 teeth profile shifted onto a 38 tooth pitch diameter. So it may seem surprising that the gearing includes two gears with 53 teeth f1, l2, whose effects cancel in the train leading to the saros dial. I have designed a small compound epicyclic gearbox with common planets. This gear turns all the gears around it and is at the very center of the entire gear system. Pdf design, load analysis and optimization of compound. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which.
For a solid shaft of diameter d, the polar moment of inertia for a hollow shaft of external diameter d and internal diameter d, the polar moment of inertia, from the above torsion equation the power transmitted. Two or four parameters model gear construction or scalar and vectorial power split. Indeed, a special, twostage planetary arrangement may utilize a gear ratio of over one hundred thousand to one. Yi zhang with susan finger stephannie behrens table of. Gears can be animated with various speed to demonstrate working mechanism. An epicylic gear is a planetary gear arrangement consisting of one or more planet epicyclic gears p meshed and rotating round a central sun gear s. The design involves planet and sun gears as one orbits the other like a planet around the sun. The number of planet gears varies depending on the design load. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes with.
Gear b is the output of the first pair and gear c is the input of the second pair. The selection of 2stage planetary gears made of plastic was mainly influenced by the need to keep noise generation as low as possible. Most mechanism of planetary gear comes with compact design and high reductive gear ratio consisting of sun. Retrieved 20 may epicyclic gears get their name from their earliest application, which was the modelling of the movements of the planets in the heavens. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3.