The outermost gear, the ring gear, meshes with each of the planet gears. The most common shape is the involute gear form but it is not our task to study this here. L where a gear a and the arm c have a common axis at o 1 about which they can rotate. Planetary gear trains are one of the main subdivisions of the simple epicyclic gear train family. The gear b meshes with gear a and has its axis on the arm o 2, about which the gear b can.
Equation and calculators to determine ratios of planetary or epicyclic gear assemblies. A thorough understanding of the sometimes difficult material is. 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. In normal operation epicyclic gear designs the planet pins are straddle mounted on a rigid carrier and are precisely aligned to each other. Design, load analysis and optimization of compound epicyclic gear trains syed ibrahim dilawer1, md. Gears in the epicyclic gear trains are one of the most critical components in. 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. Planetary gearheads are used on high precision motion control applications that. Following this step, the gear ratio is calculated by dividing the number of driven teeth by the number of driving teeth. Recent articles in gear solutions have discussed epicyclic. Planetary epicyclic gear ratios equations and calculators. Purchase handbook of automotive design analysis 1st edition. Some are listed in the bibliography at the end of this chapter. Pdf this paper deals with the gear matching of 3k planetary gears.
Starting with the basic definitions of gears, conjugate motion, and the laws of gearing, learn the tools needed to understand the inter. Calculate the input and outputs speeds and torques of gear. Designing compound epicyclic gear trains for maximum speed at high. Handbook of automotive design analysis 1st edition. A gear can be defined as a toothed wheel which, when meshed with another toothed wheel with similar configura. The gear train may be either of simple single stage or compound double stage design and the. Agma agma standard allowable torque ansiagma application application application factor bearing power loss calculated carrier ring centrifugal coefficient of friction common compound planetary cont dynamic elements enclosed drive enclosed epicyclic epicyclic drives epicyclic gear drives equally spaced planets face width float frequency gear. Performance evaluation and blade design, converter and gearbox in combinationepicyclic geartrain analysis d. 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. Pdf gears in the epicyclic gear trains are one of the most critical components. 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. Converter and gearbox in combination epicyclic gear train analysis. Grant, the application, and evaluationofgeardrives. Design manual for enclosed epicyclic metric module gear drives.
Gear wreck will happen because of its tooth fatigue and tooth surface wear, so strength design from both side is necessary. Recent articles in gear solutions have discussed epicyclic gearing, but often in the context of experienced engineers. Mullers discovery of their perfect analogy to the simple epicyclic drive trains. He designed the 3300 hp, 3200 to 1700 rpm gears for the jumo 222, the largest piston type aircraft engine developed in germany. Design, load analysis and optimization of compound. The power density of planetary gear transmissions is dependent on the adjusted number of planets linking two cen tral gears. 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. Critical speed and forced response analysis a manual for computer program. Epicyclic gear train overdrives are so arranged that the input shaft drives the pinion carrier while the output shaft is driven by the annular gear ring figs 3.
Gear design and strength iupital has good strength, durability, wear resistance, and chemical resistance, so can be used to each gear. Alexander kapelevich akgears gear design consulting. Gear design national broach and machine division,of lear siegler, inc. 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. 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. The world of planetary gears planetary gears, which can supply a lot of speed reduction and torque in a small package, have operating characteristics beyond those of fixedaxis gear trains charles. It features a sun gear, planetary gears, carrier and a ring gear. He also designed a 5000 hp, 3770 to 550 rpm marine main propulsion unit, which had a gear case three feet in diameter, 2 12 feet long, and. Describe three types of epicyclic gear boxes solve gear box ratios. This standard is applicable to enclosed epicyclic speed reducers and increasers which use spur and helical gears. 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. It applies to nonaircraft, industrial, vehicular, or machine tool gear units with carrier speeds less than 1800 rpm and pinion absolute speed less than 4500 rpm. For example bevelled gears allow the axis of one gear to be inclined to the axis of another.
Epicyclic gear systems in the range 746 to 10 445 kw fixed point is called the pitch point. Stoeckicht adapted epicyclic gears for aircraft and marine applications. This example shows an epicyclic gear drive with overall ratio of 256. The tool investigated is from atlas copco st series and consists of three main parts. Pdf design, load analysis and optimization of compound. This paper will focus on analysis and design of epicyclic gear arrangements that provide extremely high gear ratios. Lightweight design for planetary gear transmissions berndrobert hohn, karsten stahl and philipp gwinner there is a great need for future powertrains in automotive and industrial applications to improve upon their efficiency and power. A major factor in the design of spur gears is the power. Designing compound epicyclic gear trains for maximum speed at high velocity ratios, machine design, april 4, 1957.
Design manual for enclosed epicyclic metric module gear. In an epicyclic or planetary gear train, several spur gears distributed evenly around the circumference run between a gear with internal teeth and a. Design, load analysis and optimization of compound epicyclic. Gitin, handbook of gear design tata mc grawhill education, 1994.
Sizing criteria, founder of five gear manufacturing companies, lubricating considerations, material selection, and. When calculating planetary or epicyclic gear ratios, first note the number of teeth on the sun and ring gears. The design of the gear teeth also affects the relative position of one gear to another. This investigation is primarily concerned with planetary gear drives fig. We use the method introduced in epicyclic ratio calculation for determining the final gear ratio of an epicyclic gear train. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. The handbook is based on iso specifications and is a unique blend of practical as well as the theoretical aspects of gear designs. D rotation of driver per revolution of follower or the driven gear or pulley. As industrial applications required transmissions with higher power ratings, the performance of epicyclic gear systems became poorer at higher loads since. Intro planetary gears also refer as epicyclic gearing consisting three elements sun gear, planet gear and ring gear. And it can be wildly used in industry, such as printing lathe, automation assembly, semiconductor equipment and automation system. The book is profusely illustrated and analyzes many applications. Carrier ring centrifugal coefficient of friction common compound planetary cont dynamic elements enclosed drive enclosed epicyclic epicyclic drives epicyclic gear drives equally spaced planets face width float frequency gear arrangement gear manufacturer gear mesh.
It will be extremely useful to american engineers since it stresses the efficiencies of new and existing transmission designs and provides concise guide rules as well as worksheets. The new edition includes more on spiral bevel gears, arcoid gears, klingelnberg and gleason systems and gear tooth checking. If they are not the load distribution across the face is affected, but not the load sharing. Lightweight design for planetary gear transmissions. 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. Design of machinery an introduction to the synthesis and. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. Pdf program design for the 3k planetary gear mechanism with. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. He goes a bit farther and summarizes the most recent developments in transmissions.
The sun pinion and flexible annulus are centered by the planet wheels when under load. R is the angular speed of the arm, equal to the input angular speed. These drives receive an unusually clear treatment because at dr. Indeed, a special, twostage planetary arrangement may utilize a gear ratio of over one hundred thousand to one. Design, load analysis and optimization of compound epicyclic gear trains article pdf available october 20 with 1,036 reads how we measure reads.
Indeed, a special, twostage planetary arrangement may utilize a gear. Design validation of high speed ratio epicyclic gear. Sun gear is located at the center that transmits torque to planet gears orbiting around the sun gear. 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 traditional 3k planetary gears mainly rely on the query manual, and. This does not generate planetary gears, and im also unclear as to how design a planetary gear with a 2. Optimization of the gear design leading to the reduction in the load failure of. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. 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.
Following are the different types of gear trains, depending upon the arrangement of wheels. How to i design a planetary gear with a gear ratio of 2. This process helps in finding the optimized design for the epicyclic gear. In an epicyclic gear train, the axes of the shafts, over which the gears are mounted, move relative to a fixed axis. This paper presents an analysis of such uncommon gear. A twostage planetary gear stage is defined using the program. Planetary or epicyclic gear gear ratios are the rates at which the selected gears rotate relative the mechanical advantage. High gear ratio epicyclic drives analysis it has been documented that epicyclic gear stages provide high load capacity and compactness to gear drives. Add them together to calculate the number of planetary gear teeth.