The schaeffler eaxle configurator schaeffler symposium 2018. A differential is a device, usually but notnecessarily employing gears, capable oftransmitting torque and rotation throughthree shafts, almost always used in one oftwo ways. Motiondimension 2 is relative to motiondimension 1. 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. The speed ratio in ordinary gear train of fundamental kinematics units is. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes. All the components are modelled in catia to check the assembly and the. The block uses a coordinate system that produces positive tire and vehicle motion for standard engine, transmission, and differential configurations.
The second sun gear serves the same purpose as the annular gear of a simple planetary gear train, but clearly does not have the internal gear mate that is typical of an annular gear. Reduce velocity difference between two connected shafts. A planetary mesh provides the second reduction stage. Two forms of planetary gears of the bevel type are shown in figures 23 and 24.
The transmission schematic and cad model are shown in fig. Planetary gears, which can supply a lot of speed reduction and torque in a small package, have operating characteristics beyond those of. To improve load sharing, the plural planetary gears of each. Solid mechanics tutorial gear systems this work covers elements of the syllabus for the edexcel module 21722p hncd mechanical principles outcome 3.
Mechanical efficiency is an important index of gearing, especially for epicyclic gearing. Planetary gears, gear train, is 4460, torque density. Selecting gears in metric unit the gear tooth profile of the spur gear will be in module. The open rotor engine is a next generation aeroengine that satisfies the demand for high fuel efficiency and low co 2 emission. 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. The comparison of planetary gear system over helical gears systems is done on the basis of volume, weight and torque density keywords. Each planet includes at least one planetary gear set comprising plural planetary gears connected to rotate together, but having a different diameter to form a differential gear system. Since planetary gear systems are most commonly used, and techniques exist to determine equivalent planetary gear trains, a comprehensive method for analyzing the static. The following shows the gear optimization in some case studies. Special issue of the 3rd international conference on.
Because of its compact size, light weight, the capability of a high speed ratio, and the ability to provide differential action, epicyclic gearing is very versatile, and its use is. To stop the rotation of the sun, you must apply the negative gear ratio in. This model will be used to improve the current analytical methods for determining the instantaneous loads to which gear teeth are subjected. 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 basic parts of a differential is introduced first. Hence, a gear ratio of 0 given to motiondimension 2 means the sun rotates at the same speed as motiondimension 1 not necessarily 0. Pdf design and experiences of a planetary gear box for adaptive. An epicyclic gear train consists of two gears mounted so that the center of one gear revolves. I had developed this work as my semester project with a view to get familiar with the technologies as well as application. A spur gear differential is constructed from two identical coaxial epicyclic gear trains assembled with a single carrier such. A planetary system with three or four planetary pinions a hydraulic applied wet disc brake system with.
A dual planetary gear transmission having two planetary gear sets rotatably mounted on a common grounded axle wherein sun gears span both planetary gear sets providing a system for gear movement to be transferred between both gear sets whereby additional input allows modification to a differential relationship between the main transmission members. It consists of two bevel gears sun gear and two bevel gears planet gear. This gear set is formed by differential planetary gears sun gear z1, planet gear. If the carrier is acting as the input in the planetary gear system, rotating the ring gear while the sun gear is still, divide the number of teeth on the ring gear the driven gear by the. The schematic of a conventional planetary gear train is shown in fig. The structure and motion type of a planetary gearbox are more complex in comparison with a fixedshaft one, which makes condition monitoring and fault diagnosis of planetary gearbox a challenging issue in practical applications. Gl5 75w90 or equivalent type 6forward speeds and 1reverse transmission gear ratio 1st 3. Since, i am working in the metric unit every dimension will be in mm. The other two planet gears are aligned on a perpendicular axis which changes orientation with the ring gears rotation.
Similar to a harmonic drive system, one pair of gears generates differential angular motion to achieve a high reduction gear ratio. Design and analysis of differential gearbox full report download abstract abstract my project design and analysis of differential gearbox mainly focuses on the mechanical design and analysis of gearbox as transmit the power. Differential gear, in automotive mechanics, gear arrangement that permits power from the engine to be transmitted to a pair of driving wheels, dividing the force equally between them but permitting them to follow paths of different lengths, as when turning a corner or traversing an uneven road. Comparison of two designs of differential planetary gear with differential in output. Kinematics and statics analysis for power flow planet gear trains. This project was done for me 10301machine design at rowan university. Other differential designs employ different numbers of planet gears. In the two figures shown above, only one planet gear green is illustrated, however, most automotive applications contain two opposing planet gears. Differential planetary mechanism of reduction gear for robotic. The sun and planet gear converted the vertical motion of a beam, driven by a steam engine, into circular motion using a planet, a cogwheel fixed at the end of the connecting rod connected to the beam of the engine. Figure 4 user interface of mdesign gearbox with 3dgeardesigner and result page ref. The most basic form of planetary gearing involves three sets of gears with different degrees of freedom. Remove the planetary ring gear using prying slots in the wheel bearing cage.
This is the final design of a differential planetary gearset. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Differential is an arrangement of gears which work together and allow the vehicle to take a turn smoothly. Modeling a differential planetary gear train with backlash and teeth damage the differential planetary gear chosen for study has two inputs and one output 11, 12. This transmission system can be screw type or gears type. Planetary gearing could increase torque and reduce load inertia while slowdown the speed. Similar to a harmonic drive system, one pair of gears generates differential. Pdf comparison of two designs of differential planetary. 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. Design and test of differential planetary gear system for. Also the case study to determine the reduction ratio of two stage gear box is discussed. Planetary gearbox vibration signal characteristics.
Highratio speed reducer based on elastic deformation of an elliptical gear. On completion of this short tutorial you should be able to do the following. For this reason, this class of gear is often referred to as a planetary system. Differential planetary mechanism of reduction gear for. A torque transfer device has plural planets arranged for planetary rotation about one or more sun gears and within one or more ring gears. It includes 3d printed, laser cut, and also purchased gears. 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.
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. In terms of its functionality, there are no differences in comparison to. Planetary gear train with two meshed planet gear sets. The planet gear in figure 23 rotates about a fixed bevel gear at the center of which is the driven shaft. Article information, pdf download for differential planetary. Gear mechanism that allows driven shafts to spin at different speeds. While a harmonic drive system utilizes slightly different number of gear teeth between the flex spline and the circular spline to induce differential motion, a planetary gear mechanism with different gear modules. Typically, each gear mesh will have 1%2% loss in efficiency, so with three different meshes from the transmission shaft to each of the half shafts, the system will. The main purpose of the transmission system is to allow a change of gear. Paper open access the strength analysis of differential. The block is suitable for use in hardwareintheloop hil and optimization workflows.
Pdf comparison of two designs of differential planetary gear. A significant feature of the schaeffler electric axle is the integration of a differential with a planetary design as an alternative to the bevel gear differential 1. To compare with traditional gearbox, planetary gear has several advantages. Design and optimization of planetary gears considering all. In this case, the planet gears have 12 teeth, the sun gear has 18 and the ring gear has 42 teeth. 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. Nasatm2011217127 3 the pinion is straddle mounted and the gear is overhung. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which. Normally, the ring gear is stationary, causing the planets to orbit the sun in the same rotational direction as that of the sun. When the vehicle is traveling in a straight line, there will be no differential movement of the planetary system of. The proposed design is based on a solution with a differential planetary gear system in which the second degree of freedom is activated when.
Planetary gear ratio calculations this article also available in spanish. Planetary gear is one of the epicyclic gear, which is a gear system consisting. The angular speed of the planet carrier can be found since we know. With the motion of the beam, this revolved around, and turned, the sun, a second rotating cog fixed to the drive shaft, thus generating rotary motion. Planetary epicyclic gear ratios equations and calculators. Differential helps in turning the drive wheels at different rpm while the vehicle takes a turn. Working out planetary gear turns ratios working out the gear ratio of a planetary gear train can be. Introduction planetary gear systems normally consist of a centrally pivoted sun gear, a ring gear, and several planet gears found. Planetary gearboxes are widely used in helicopters, wind turbines, mining machinery, and so forth. In the differential, bevel pinion gear is fixed to the propeller shaft which rotates the crown wheel. Design and numerical characterization of a new planetary.
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