Spur gears, planetary gears, gearhead, servo drive, optimization. Finally by combining equation 2, 5 and 8 the following expression for. In this paper a new solution is considered for improving the efficiency of planetary transmissions. The planetary gearset is much more versatile, since it has two inputs and one output. Former basic units 1c planetary carrier and 1s sun gear are connected to units 2r inner ring and 2c planetary carrier of differential gear train, respectively. It allows the car to operate like a parallel hybrid the electric motor can power the car by itself, the gas engine can power the car by itself or they can power the car together. Design, load analysis and optimization of compound epicyclic. By application of the planetary reduction gear in design of grabs hoisting mechanism, the overload of the hoisting rope or insufficient closure of grabs clamshell are prevented. Planetary gears are common in transmission systems, where they provide high gear ratios in compact geometries.
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. The research program covers basic ideas of the design of the proposed gear drives. Choosing which piece plays which role determines the gear ratio for the gearset. All the components are modelled in catia to check the assembly and the. The power density of planetary gear transmissions is dependent on the adjusted number of planets linking two central gears. The kinematic scheme of loadsplit twostage planetary gear is shown in figure 1, which is composed of closed planetary gear train and differential planetary gear train.
Planetary gear train with stepped planet gear set matlab. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. The main purpose of this planetary was to see if i could make it with hand cut gears and how smoothly it would operate. A reliabilitymodel is presented for planetary gear trains in which the ring gear is. Lightweight design for planetary gear transmissions.
Driver planetary gear character istics this is a c o mp li c a t e d m e c h a n ism to solve. Calculate gear ratio by dividing the number of teeth on the driven gear by the number of teeth on the driving gear. The input power of a central gear is then distributed to several planet gears, resulting in lower load and lower tooth forces for each gearing. A planetary gear system, also referred to as epicyclic gearing, consists of three elements a sun gear, one or more planet gears, and a. Planetary geared motors are co mpletely filled in accordance with the information on the nameplate of the planetary gear unit with an oil of the corresponding type and viscosity. A carrier connected to a drive shaft holds the planet gears. Jan 12, 2015 the rule for calculating the power distribution on a power split planetary gear system is based on the equal force rule. A twostage planetary gear stage is defined using the program. Gear optimization macrogeometry the following shows the gear optimization in some case studies. Reliability model for planetary i gear trains 1 ntrs nasa.
Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. Calculate gear ratio by dividing the number of teeth. One of the planetary gearsets from our transmission has a ring gear with 72 teeth and a sun gear with 30 teeth. Two forms of planetary gears of the bevel type are shown in figures 23 and 24. Pdf relations between size and gear ratio in spur and. You can click on any of the images for a larger view. Powersplit planetary gear set power calculation physics forums.
The sun gear is located at the center, and transmits torque to the planet gears that orbit around it. Provided that the ring gear has a constant size, different ratios can be realized by varying the number of teeth of the sun gear and the number of teeth of the planetary gears. Design and optimization of planetary gears considering all. Before startup, correct the oil level in accordance with the quantity information on the nameplate of the planetary gear unit. The angular speed of the planet carrier can be found since we know the. Ronald walters multilayer planetary drive ronald walters sent me some pictures and a description of a very complicated planetary gear drive that he built.
Relations between size and gear ratio in spur and planetary. Here, you will find offtheshelf, highly sophisticated drive and gear unit solutions. Analysis of dynamic behavior of multiplestage planetary gear. Design of machinery an introduction to the synthesis and. Power analysis and efficiency calculation of the complex. The results show that the graphical representation is a simple, intuitive and practical method for power analysis and efficiency calculation, it can provide theoretical references for design work of the complex and closed planetary gears transmission. The software enables calculation of the system gearbox in one step, including a complete documentation into a pdfa document, according to iso 190051. Ports c, r, and s represent the shafts connected to the planet gear carrier, ring gear, and sun gear. Calculation of load distribution in planetary gears for an effective gear design process, agma 2 john argyris, alfonso fuentes, faydor l. Structure and features 4 types 5 standard reduction ratio ip 6 recommended lubrication oils 6 selection of. Tangential force of the planet carrier as well as centrifugal force of the planet are calculated. Modelling planetary gearpairs has become more complex because of a new mech designer rule the new rule is you cannot use the same line as the lineofcentres for more than one gearpair before r11.
That is to say, the number of teeth in the ring gear is equal to the number of teeth in the middle sun gear plus twice the number of teeth in the planet gears. Planetary gear design a planetary gear system, also referred to as epicyclic gearing, consists of three elements a sun gear, one or more planet gears, and a ring gear. A question that i often get is how to work out planetary gears using the gear template generator. Rrtdrrwd t2max nm1,00050,000 ratio5179 compact planetary drives. From the torque on the carrier we determine the force on the carrier based on its radius. Planetary gear ratio calculations this article also available in spanish. Planetary gear is a widely used industrial product in midlevel precision industry, such as printing lathe, automation assembly, semiconductor equipment and automation system. Litvin, computerized integrated approach for design and. Another class of gear train has wide application, the epicyclic or planetary train.
Design, load analysis and optimization of compound epicyclic gear trains syed ibrahim dilawer1, md. Our standard product range already includes solutions for a large number of specific requirements that need to be taken into consideration in a great variety of applications. Combining equation 19 with equations 29 and 30 yields the expression. Design, load analysis and optimization of compound. Planetary gear system is use in varies applications such as, clocks, lunar calendar, car. The power split device also allows the car to operate like a. Pdf relations between size and gear ratio in spur and planetary. Planetary gearing could increase torque and reduce load inertia while slowdown the speed. Tobias schulze standardized calculation methods such as iso 6336 and din 3990 already exist to determine the load distributions on gears inside a planetary gearbox, but by their very universal nature. For example, if the sun gear has 20 teeth and the ring gear has 60, the planetary gear has 80 teeth. Atlas copcos previous knowledge about power losses in planetary gears. The above formula for probability of survival reflects the observed. Each of these three components can be the input, the output or can be held stationary. 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.
Understanding, selecting and applying planetary gearheads. Application of planetary reduction gear in operation of. The asymmetrical design gives special operation features. New types of planetary face gear drives the developed face gear drives are shown in figs. Relations between size and gear ratio in spur and planetary gear trains 2035 the radius of the planet carrier is the radius of the sun gear plus th e radius of the planet.
Application of planetary reduction gear in operation of the. The power split device is the heart of the toyota prius. Calculate the input and outputs speeds and torques of gear boxes. Analysis of dynamic behavior of multiplestage planetary. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Elecon also manufacturers helical planetary gearbox and bevel planetary gearboxes. This planetary gear train consists of a sun gear yellow, planet gears blue supported by the. This technical product information tpi 08, planetary gear bearing. It is possible that it automatically decides combination and center distance of the troublesome teeth number, etc. The sliding force is the amount of force needed to slide the surfaces, combine it with the. The rule for calculating the power distribution on a power split planetary gear system is based on the equal force rule. The compound planetary gear block represents a planetary gear train with composite planet gears. You will see below, the models use one line as the lineofcentres for gearpair 1 and gearpair 2 r11 and after.
This paper presents planetary gear transmissions, designed according to iso 6336 ref. To add a second gearpair, you must add a second line with a. The calculation of the load capacity according to din 3990 method b is also part of the module. Most commonlyencountered geartrains are relatively simple, having only one input and one output, and thus only one overall ratio. Each composite planet gear is a pair of rigidly connected and longitudinally arranged gears of different radii.
Using lever analogy diagrams in teaching compound planetary. In addition to the geometry calculation, the torques, speeds, relative speed of the planet gear, power, pitch power, coupling power are determined as well. To compare with traditional gearbox, planetary gear has several advantages. Design and numerical characterization of a new planetary. 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. Research laboratory new design and improvement of planetary. We use the method introduced in epicyclic ratio calculation trqin determining the final gear ratio of an epicyclic gear train.
Two inputs are needed to obtain a predictable output. In some cases, such as the automotive differential, one input is provided the. All 34 types can be derived from one general form of the simple planetary gear train. The next steps depend on the state of the planetary gears connected to the carrier, although all use the same formula. In the past ive had luck using this site to create an illustrator file that i can extrude in rhino. Kinematic equivalence of planetary gear transmissions muellers book ref. Compound gears are simply a chain of simple gear trains with the input of the second being the output of the first. This block models a gear train with sun, planet, and ring gears. This means a planetary gear with say three planets can transfer three times the torque of a similar sized fixed axis. This is a clever gearbox that hooks the gasoline engine, generator and electric motor together.
The proposed new planetary transmission can be considered a cvt with a planetary gear set. The first constraint for a planetary gear to work out is that all teeth have the same pitch, or tooth spacing. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. 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. Technically, a meaningful ratio range for a planetary stage is approx.
New types of planetary facegear drives the developed facegear drives are shown in figs. Determination of load distributions on double helical. This does not generate planetary gears, and im also unclear as to how design a planetary gear with a 2. Pdf in this report equations for the minimum gear sizes necessary to drive a. The common planet gear is engaged with the sun gear, and both the stationary and the rotating ring gears.
Planetary gear drive of high reduction ratios, clutches, etc. The next chapter explains the matlab calculation program based on the. In planetary gears, torque density can be increased by adding more planets through multiple gear mesh points. At the same time, expectations for gear reliability are high. Epicyclic gearing planetary gearboxes neugart gmbh. 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. Planetary gear boxes chapter 10 4 technical information table 1 thermal power adjustment factor fk work time % room temperature c 10 20 30 40 50 100 1. I was trying to do the bearing calculation for planetary gear.
The spur planetary gear torsional stiffness and its. This does not allow for specific sliding velocities in each mesh to be equalized, resulting in a reduction of gear efficiency. At the variation interval of revolution speed, the change rate difference of loadsharing coefficient between internal and external meshing of firststage planetary gear train is significantly different. If there npetl more than one arm in the planetary gear train. The planetary gear and mechanical paradox gear design system software can do the design of the planet gear and the mechanical paradox gear easily. Working out the tooth counts for planetary gears is actually not that complicated, so i initially neglected to mention how to do it. Powersplit planetary gear set power calculation physics. Index terms epicyclic gear train, power split device.
Planetary epicyclic gear ratios equations and calculators. Additionally, there is a diversity of planetary gears for different applications. Development of a design tool for a twodegree of freedom gear. Planetary gear trains pdf planetary gear is one of the epicyclic gear, which is a gear system consisting of. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes.
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