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. We have already discussed that in an epicyclic gear train, the axes of the shafts, over which the gears are. Design and optimization of planetary gears considering all relevant influences tobias schulze gear design process lightweight construction and consideration of available resources result in gearbox designs with high load capacity and power density. It features a sun gear, planetary gears, carrier and a ring gear. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can. D rotation of driver per revolution of follower or the driven gear or pulley. 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. Free learn about recent technology and improve the knowledge. R is the angular speed of the arm, equal to the input angular speed. We present here a simple, methodical procedure for determining the final gear ratio of an epicyclic gear train.
Here is a gearset with a stationary ring gear and three planet gears on a rotating carrier. Gear transmissions usually exhibit high powertoweight ratios. 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. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. The angular speed of the planet carrier can be found since we know the. Design, load analysis and optimization of compound epicyclic. The gear have more than one gear on the shaft in any epicyclic gear trains, there is called compound epicyclic gear train. Working out the tooth counts for planetary gears is actually not that complicated, so i initially neglected to mention how to do it. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Recent articles in gear solutions have discussed epicyclic gearing, but often in the context of experienced engineers.
Calculate the suitable numbers of teeth for the gears. A question that i often get is how to work out planetary gears using the gear template generator. Epicyclic gearing or planetary gearing is a gear system that consists of one or more outer gears, or planet gears, revolving about a central, or sun gear. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. They are used to increase or decrease the speed or torque of the output shaft. As industrial applications required transmissions with higher power ratings, the performance of epicyclic gear systems became poorer at higher loads since. Sort by date 1 gear ratio epicyclic drives analysis. By utilizing the gear calculator introduced here, it is possible to reduce these burdens substantially. Choosing which piece plays which role determines the gear ratio for the gearset. Two inputs are needed to obtain a predictable output. Tabular method for epicyclic gear trains watch more videos at. 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.
Jan 17, 2018 tabular method for epicyclic gear trains watch more videos at. Pdf epicyclic gear train dynamics including mesh efficiency. At the same time, expectations for gear reliability are high. 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. This investigation is primarily concerned with planetary gear drives fig. When there is only one gear on each shaft, as shown in fig. 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. Design, modelling and analysis of a 3 stage epicyclic planetary reduction gear unit of a flight vehicle k akhila1 and m amarnath reddy2 corresponding author. 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. As the input power flow and ouput one are on the same axes, the efficiency of the gearbox is directly obtained from the efficency of the basic epicyclic gear, which depends on speed, torques and. Sharing is caring 1 1sharegear ratio is the ratio of output and input number of teeth on a shaft. Calculate the input and outputs speeds and torques of gear boxes.
Example for, sun and planet gear is a compound epicyclic gear train. In conventional drafting either manual or computer assisted, various views of a part are created in. Equation and calculators to determine ratios of planetary or epicyclic gear assemblies. 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. How to derive and calculate epicyclic gear ratio equations.
Planet gear for each planet gear, we can write nslr as follows. Example 6 figure shows a compound epicyclic gear train. A twostage planetary gear stage is defined using the program. Scribd is the worlds largest social reading and publishing site. 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. Introduction to epicyclic gear train working and advantages and disadvantages of the epicyclic gear train. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. Recent articles in gear solutions have discussed epicyclic gearing. Gear generator is a tool for creating involute spur gears and download them in svg format.
Mar 30, 2016 epicyclic gear train 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 gear ratio calculations for various gear train. 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. Ability to calculate the gear ratios, torques, and effective inertia for simple, compound. Epicyclic gearing is the basis of a planetary gearbox design. Planetary gear drive of high reduction ratios, clutches, etc. Epicyclic gearbox, rim stress, finite element analysis, ring gear 1. On completion of this short tutorial you should be able to do the following. Free body diagrams of gear trains american society for. The planet gear are mounted on a moveable arm carrier. Download limit exceeded you have exceeded your daily download allowance. Join 5,000 engineers with over 3,070,000 free cad files join the community. Epicyclic gearing systems may also incorporate the use of an outer ring gear or annulus, which meshes with the planet gears.
The planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear. Epicyclic gearset gears 6 an epicyclic gear set has some gear or gears whose center revolves about some point. Pdf the paper presents an epicyclic gear train dynamic mathematical model including. Lock the arm and assume other wheel is free to rotate. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. This example shows an epicyclic gear drive with overall ratio of 256.
Design, load analysis and optimization of compound. Pdf epicyclic drive trains download read online free. The derivation for gearing ratios between sun gear, planet carrier and ring gear motions are given in the attached excel file. The tool investigated is from atlas copco st series and consists of three main parts. The circulation of the spur gear takes place in analogy to the orbiting of the planets in the solar system. Pdf the mechanical efficiency of epicyclic gear trains. This method is extremely procedural, which is appropriate since use of intuition is often quite futile when applied to complex gear trains. Types of gear train and velocity ratio calculation.
Epicyclic gearing also called as planetary gearing. Sun gear is located at the center that transmits torque to planet gears orbiting around the sun gear. 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. Epicyclic gear train, output torque, holding torque. Gears can be animated with various speed to demonstrate working mechanism. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. In this research paper torque calculations are done for epicyclic gear.
Planetary or epicyclic gear train epicyclic gear train. A gear train is a combination of gears used to transmit motion from one shaft to another. Calculate gear ratio by dividing the number of teeth. The gear calculator is a comprehensive software which, after inputting various parameters related to gear calculations, computes online automatically gear sizes, strengths, working forces, tooth forms, backlash conversions, etc. It is a gear system that consists of one or more outer gear planet gear rotating about a central sun gear. 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. Designing compound epicyclic gear trains for maximum speed at high velocity ratios, machine design, april 4, 1957.
Each of these three components can be the input, the output or can be held stationary. For example, if the sun gear has 20 teeth and the ring gear has 60, the planetary gear has 80 teeth. Sep 04, 2018 planetary calculatilns with spur and helical toothing. In an epicyclic or planetary gear train, several spur gears distributed evenly around. All other applications, including machines that run for more than. The gears were modeled procedurally with a python script i wrote, and the rotation values for the. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. Jun 15, 2010 the planet gears red are being driven by the sun gear green and the ring gear light blue. Design of machinery an introduction to the synthesis and.
Pdf on aug 18, 2014, amar kumar and others published epicyclic gear train mechanism find, read and cite all the research. This is a comprehensive text and reference book for students and teachers of mechanical engineering, for design and research engineers, and for manufacturers and users of gear trains for the transmission of power in industry and transportation. However, advances in internal gear manufacturing did not parallel those in external gears, limiting the development of epicyclic gear trains. Epicyclic planetary gear train model with three configurations. Planetary epicyclic gear ratios equations and calculators. Epicyclic gear train an 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 epicyclic gear trains syed ibrahim dilawer1, md. Introduction to epicyclic gear train working and advantages. Jul 06, 2019 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. Hi, this is a simple, configurable, epicyclic planetary gear train created in creo parametric 3. It is therefore imperative to always calculate the speed of the sun, planet. Calculate gear ratio by dividing the number of teeth on the driven gear by the number of teeth on the driving gear. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. The next steps depend on the state of the planetary gears connected to the carrier, although all use the same formula.
Another class of gear train has wide application, the epicyclic or planetary train. This paper will focus on analysis and design of epicyclic gear arrangements that provide extremely high gear ratios. With a limited space, high reduction ratios are achieved by reducing the dimen sions of the teeth and the pinion. Intro planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet gear and ring gear. It has been documented that epicyclic gear stages provide high load capacity and compactness to gear drives. Planetary gear ratio calculations this article also available in spanish. 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 definition of epicyclic by the free dictionary. As more and more of these engineers reach retirement age younger engineers must pick up where they left off, and for many epicyclic gearing is an area where they lack experience. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear. 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.
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. This important for handheld torque wrenches leads to very light weight tools. The planetary gear train arrangement in general has a central sun gear which. The planet gears red are being driven by the sun gear green and the ring gear light blue. Because gear calculations require many complex formulas related to strengths and sizes, traditional gear design situations require highly specialized knowledge and suitable design time. 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. How to derive and calculate epicyclic gear ratio equations in. If needed, the free basic edition of netfabb for can be used to repair a. One of the planetary gearsets from our transmission has a ring gear with 72 teeth and a sun gear with 30 teeth. Intuitive method how to calculate derive gear ratio formulas equations for planetary epicyclic gear. Design and optimization of planetary gears considering all. Designing compound epicyclic gear trains for maximum speed at high. 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.
322 1308 287 903 1629 865 378 1267 517 1257 720 1622 1503 1529 1119 390 915 1017 745 945 449 1309 1083 891 720 822 687 291 54 212 1218 124 1196 161