Design of machinery an introduction to the synthesis and. Calculat ion of a plane tary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. The sun gear is located at the center yellow, and transmits torque to the planet gears blue which are typically mounted on a moveable carrier green. Intro planetary gears also refer as epicyclic gearing consisting three elements sun. Small gear driving large gear under drive under drive happens when carrier is the output under drive increases torque decreases speed large gear driving smaller gear overdrive overdrive happens when the carrier is the input if the carrier is held, the gear set goes to reverse. Planetary gears are common in transmission systems, where they provide high gear ratios in compact geometries. The sun gear is located at the center, and transmits torque to the planet gears that orbit around it. In each case, one of the two inputs is fixed, and the other input makes one full rotation. The gear ratio formula for two meshing gears is simple and intuitive, while the gear ratio formula for the planetary mechanism is not. Lightweight design for planetary gear transmissions. One of these gears is planetary gear, which enables input from motor to transmit as output to reduce or speed up ccaxially. The angular speed of the planet carrier can be found since we know the. The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines. If the carrier is acting as the output in the planetary gear system, being rotated by the sun gear while the ring gear stays still, divide the number of teeth on the planetary gears the driven gear by the number of teeth on the sun gear the driving gear.
Each of these three components can be the input, the output or can be held stationary. This is particularly true for planetary gearboxes in industrial gear boxes, since such gearboxes must transmit very high power levels with high operational security within a very small design envelope. As we turned the planet gear it traversed the sun gear and imparted more rotation to the carrier. In the past ive had luck using this site to create an illustrator file that i can extrude in rhino.
Design, modelling and analysis of a 3 stage epicyclic planetary reduction gear unit of a flight vehicle k akhila1 and m amarnath reddy2. A compound configuration for planetary gear train is selected and an optimization. The basic form of a planetary gear system is shown in figure 17. Pdf investigation of materials for shaft and sun gear of a. Internal gear strains and load sharing in planetary. A planetary mesh provides the second reduction stage. The input and output axes of a planetary gear system are on a same line. Also the case study to determine the reduction ratio of two stage gear box is discussed. Sun gear p planet gear r ring gear a a r m ex ampl e. Jan 09, 2018 the gear ratio formula for two meshing gears is simple and intuitive, while the gear ratio formula for the planetary mechanism is not. Since planetary gears mesh with the sun gear and ring gear at several locations, more teeth are engaged to drive the load, compared to a conventional gearand.
Planetary gear trains are common in industrial, automotive, and aerospace systems. The bevelgear shaft is connected through a spline to a sun gear. A typical epicyclic planetary gear system by reason of the planet gears being connected to two other gears, carrier rotation is affected by two gear chains. Because of the speed constraint shown in equation 1, the planetary gear, despite of the fact it has three nodes, only has two. The central gear around which the planet gears revolve. Planet sun gear gear pinion pinion lowspeed stage highspeed stage intermediatespeed stage lowspeed shaft. Planetary gear ratio calculations this article also available in spanish. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear.
It consists of a sun gear a, planet gears b, internal gear c and carrier d. The angular velocity of gear 2 relative to the arm in revmin is the velocity of gear 5 relative to the arm is 47 sun gear 2 arm 3. How to derive and calculate epicyclic gear ratio equations in. Ideal planetary gear with sun, ring, and carrier simulink. For further information, please contact the lonne scandinavia main office service tlf. I forgot to point out that the 17hp in this particular example that is sent to mg2 mechanically from the psd and then returned to mg1 electrically is the virtual power i was mentioning from an earlier post. Planetary gearbox fault detection using vibration separation. Design and optimization of planetary gears considering all. They are great speed variation mechanisms, and are often.
A planetary gearbox with flexible pin design developed by itri taiwan for 2mw wind turbine pdfill pdf editor registration keys is. The comparison of planetary gear system over helical gears systems is done on the basis of volume, weight and torque density keywords. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3. A twostage planetary gear stage is defined using the program. A planetary gear system, also referred to as epicyclic gearing, consists of three. Pinion gear 8 pitch diameter 4 planet carrier 11 planetary gear set 11 power transfer unit 16 rearwheel drive rwd ring gear 11 spiral bevel gear 6 spur gear 5 sun gear 11 torque 2 torque converter 11 transaxle transfer case 16 transmission 8. To determine the gear condition in a simple planetary gear set always look at what the carrier is doing. A carrier connected to a drive shaft holds the planet gears. Power train configuration of the toyota hybrid system.
Because there are three red gears instead of one, this gear. Typically, the arm and the sun gear will each be driven in some direction at some velocity. Gearbox typical failure modes, detection and mitigation. And it can be wildly used in industry, such as printing lathe, automation assembly, semiconductor equipment and automation system. The bevel gear shaft is connected through a spline to a sun gear. Patel institute of engineering, vitthal udyognagar abstract.
In this case, maximum values fr and fa are not shown. A planetary gearing system comprising a planet carrier and planet gear wheels and planet friction wheels supported on planet wheel shafts on said planet carrier, said planet gear wheels cooperating with a gear ring encircling them and a sun gear wheel, said planet friction wheel cooperating with a friction ring circumscribing them and with a sun friction wheel, a housing enclosing the planet. A typical application is the automatic transmission system of car. Choosing which piece plays which role determines the gear ratio for the gearset. The basic form of planetary gear system is shown above. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. Pdf design and conduct of precision planetary gear vibration. This block models a gear train with sun, planet, and ring gears. 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 was invented by the scottish engineer william murdoch, an employee of boulton and watt, but was patented by james watt in october 1781. The block calculates the dynamic response to the sun, carrier, and ring input torques. Planet gears 4 drive ring gear 5 in same direction ccw 6. The planet gears are connected to each other through a common carrier which allows the gears to spin on shafts called pinions which are attached to the carrier. Pdf analysis of stresses and deflection of sun gear by.
When ring gear is fixed, input is given to turbine coupled to carrier and output is extracted from sun gear coupled to generator, planetary gear transmission acts as. One of the planetary gearsets from our transmission has a ring gear with 72 teeth and a sun gear with 30 teeth. 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 a planetary gear train functions analogous to solar system. From our study of normal 2 gear interactions we know that the amount of traversal is determined by the number of teeth on each gear.
Figure 19 is a fem model used for loaded tooth contact analysis of the planetary gear z 2 with the internal gear z 3. In more than a few cases, the planetary gears in particular are subjected to loads up to their physical limits. Planetary gear system planet gear b, z b sun gear a, z a carrier d internal gear c, z c planetary gear system the basic form of planetary gear system is shown above. Planetary gears, gear train, is 4460, torque density. If ever the carrier is an output in a simple planetary gear set, the condition will be forward reduction. Planetary gear bearing arrangements in industrial gearboxes. Feb 28, 2017 the planetary gear set, also known as the epicyclic gear train, is one of the most important and interesting inventions in engineering. It is certainly true that it takes a skilled gear engineer to master all of the intricate aspects of designing this type of gear system. Nasatm2011217127 3 the pinion is straddle mounted and the gear is overhung. Other uses for gears how gear ratios work howstuffworks. The selected materials had to meet strength requirements while being cost effective. In some helicopters planetary gear vibration is the primary source of cabin noise that can exceed 100db. All three are attached to a plate the planet carrier, and they engage the inside of the blue gear the ring instead of the outside.
The load dependent variable gear mesh stiffnesses were incorporated into a practical torsional dynamic model of a planetary gear system. In this tutorial, we will show you an original and easyto. This model will be used to improve the current analytical methods for determining the instantaneous loads to which gear teeth are subjected. Before 1990, the literature on analytical planetary gear dynamics is scarce. Calculate the number if teeth required in the ring gear for the ratio 5. Ports c, r, and s represent the shafts connected to the planet gear carrier, ring gear, and sun gear. A typical planetary gear set consists of three components carrier joining all planet gears, ring gear, and sun gear and each of these three components can be used as the input, output, or kept stationary. The sun gear is twice the diameter of the planet gear, and the ring gear is twice the diameter of the sun gear. The system is then held together by an arm connecting the planet gears in combination with a ring gear. Pdf gearing is one of the most critical components in mechanical power. Automatic transmission basics linnbenton community. Engine generator motor ring gear pinion gear sun gear carrier gear battery planetary gear set inverter vehicle fig. 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.
Drive selection in a mechanical transmission system, a drive is a device. Gearbox typical failure modes, detection and mitigation methods. A planetary train composed of sun gear 2, an arm or carrier 3, and planet gears 4 and 5. By locking or releasing certain gears, it has the advantage of operating the car at different speeds. In our gearheads the internal gear is fixed, the sun gear is the input pinion, and the output shaft. The fundamentals of planetary gear systems gear motions. 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. On completion of this short tutorial you should be able to do the following. This does not generate planetary gears, and im also unclear as to how design a planetary gear with a 2. From a kinematic point of view, what sets this mechanism apart is the kinematic constraint set between gear. It consists of a sun gear a, planetary gears b, internal gear c and carrier d. Calculate the input and outputs speeds and torques of gear boxes. Helical nonzero helix angle planetary gear system is mostly used at low noise place and quieter applications like medical equipment, wind power plant compared to spur zero helix angle.
How to i design a planetary gear with a gear ratio of 2. We would like to show you a description here but the site wont allow us. Conceptual design of planetary gearbox system for constant. Planetary gears, which can supply a lot of speed reduction and torque in a small package, have operating characteristics beyond those of. In this gear system, the yellow gear the sun engages all three red gears the planets simultaneously. At first glance, planetary gear systems, also known as epicyclic gear systems, appear to be quite complex. In this model, the sun gear has three degrees of freedom. Planetary gear design pdf pin mechanism for planetary gear drives in wind turbines. Planetary gear system consists of three kinds of gears.
Table 1 parameters of the test gear set parameter sun planet ring number of teeth 73 26 125 normal module, mm 1. A planetary gear train planetary trains always include a sun gear, a planet carrier or arm, and one or more planet gears. Introduction planetary gear systems normally consist of a centrally pivoted sun gear, a ring gear, and several planet gears found. A planetary gear set is made up of three types of gears. At the same time, expectations for gear reliability are high. 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. The basic planetary gear set consists of a sun gear, a ring gear and two or more planet gears, all remaining in constant mesh. Determine the angular velocity of each of the planet gears. In many cases, one of these inputs will be zero velocity, i. 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.
The planetary gear block implements an ideal planetary gear coupling consisting of a rigidly coupled sun, ring, and carrier gears. The planet gears orbit around the sun gear and mesh with an outer ring gear pink. F gear units are usually applied in the transmission of a torque without radial loads. Torsional vibrations and dynamic loads in a basic planetary. The planetary gear system is used in an automatic transmission for an automobile. Outer gears meshes with an outer internal geared wheel willis formula allow to calculate reduction ratio for an epicyclic gearbox. The input shaft was modelled as a cantilever beam carrying the weight of the. Guard and boot seal system a boot seal and metal guard are available in the model 6, 9 and 10 spindle output units only. Epicyclic gearing or planetary gearing is a gear system that consists of one or more outer gears, or planet gears, rotating 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. Pdf investigation of materials for shaft and sun gear of. This has become an epicyclic train with a sun gear and a planet gear orbiting around the sun, held in orbit by the arm. The dynamic model consists of input and output units, shafts, and a planetary train. Notice by the center indicator that the sun gears stays fixed while the planets turn.
234 832 1240 8 934 369 1081 515 892 1291 1192 1042 1469 1087 500 577 1544 68 173 1475 5 1517 1026 671 152 274 332 239 868 323 1319 818 244 482 969 466