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. 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. We feature a compact design with high power density thanks to equal force distribution among three planetary gears and robust performance due in part to hardened gears. The test ring gear was strain gaged according to the schematic shown in fig. This is because the planet carrier circled the sun gear once in the same direction as it was spinning, subtracting one revolution from the sun gear. By type, the sun and planet gears are crossed helical spur gears arranged as a wormgear transmission, in which the planet gear is a worm. Planet gear for each planet gear, we can write nslr as follows. Planetary gears are common in transmission systems, where they provide high gear ratios in compact geometries. I was trying to do the bearing calculation for planetary gear.
Either the sun or ring gears may be fixed, the other performs rotation about its axis fig. The rule is that the forces on the sun and ring from the carrier are always equal to one half each of the carrier force. Slide out planet gear subassembly from the window of the carrier 6a. By type, the sun and planet gears are crossed helical spur gears arranged as a worm gear transmission, in which the planet gear is a worm. If the link rotates about the fixed point b at 4 rads, determine the angular velocity of the ring gear r.
So four design variables are considered namely module m, number of teeth on sun gear t1, number of teeth on planet gear t2 and face width of gear b. Let n1, n2, n3 be the numbers of teeth of the sun, planet, and ring gears, and. This can be designed by the feeli ng which is the same as the equality position of planet gear. The planet gear a is pin connected to the end of the link bc. The two sun gears are centrally located and separated longitudinally along a common rotation axis. In many cases, one of these inputs will be zero velocity, i. Other articles where sunandplanet gear is discussed. Since the number of planets is a variable in this study, a family of planetary carriers was designed and procured to form 3 to 6 planet gear sets. Sun 1 long planet ring sun 1 long planet short planet sun 2 kinematics of planetary gear trains angular velocity relations in a planetary train, the sun, carrier and ring rotate on coaxial shafts. 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. The sun and planetary gear arrangement, sometimes also called as epicyclic gear train, is a gear train, where typically few smaller gears rotate and revolve by meshing around a bigger 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. Lecture 8 planetary gear train planetary gear trainspgt.
At the second stage, the planet carrier acts as the input for. Other uses for gears how gear ratios work howstuffworks. The production version of the test gear set uses a 6 planet carrier. Compare planetary gear reducer price super offer from. Premium nuts, dried fruit, chocolates, sweets and more at great prices. Planetary gear drives are constituted by three main elements.
Buy high quality and affordable planetary gear reducer via sales. The sun planet worm gear block represents a twodegreeoffreedom planetary gear built from carrier, sun, and planet gears. The ravigneaux gear block represents a planetary gear train with dual sun and planet gear sets. Research laboratory new design and improvement of planetary. At the second stage, the planet carrier acts as the input for the second planetary gear set, the larger sun gear. As ts is the rotation of the sun, and tc is the rotation of the carrier then so far in the absence of the planets turning we have equal rotation of the sun and carrier. Then, for such a configuration, the absolute speeds of carrier and planet are 11 c n nn, and 11 2 2 2 n n.
Then solve the above problem if the sun gear d is rotating clockwise at v d 5 rads while link bc rotates counterclockwise at v bc 4. You could rearrange things again, and this time hold the sun gear stationary, take the output from the planet carrier and hook the input up to the ring gear. Internal gear strains and load sharing in planetary. There will be another component added to the rotation due to planet rotation but at this point they are equal. Dynamic load sharing characteristics and sun gear radial. At the same time the pinion gear carrier and the sun gear are made from a higher grade steel to handle motors with higher horse power and torque levels. Experimental analyses of vibration and noise of faulted. Planetary gear with two sun gears and two planet gear sets. The even distribution of the transmitted horsepower on 3 to 5 planetary gears.
The sun gear is located at the center, and transmits torque to the planet gears. The solution of differential governing equation of motion is determined by applying the fourier series method. The figure at left shows a threedimensional view while the figure at right provides a crosssection. Multi objective optimization of planetary gear train. The sun and planet gear of james watt, actually invented by william murdoch, as a non patentinfringing alternative to the crankshaft for his rotative beam engines. The same gears were used in all the carrier builds. Sunandplanet gear definition of sunandplanet gear by.
Gear train with sun, planet, and ring gears matlab. This has become an epicyclic train with a sun gear and a planet gear orbiting around the sun, held in orbit by the arm. Powersplit planetary gear set power calculation physics. The angular speed of the planet carrier can be found since we know. Oct 15, 20 high torsional stiffness since the sun gear will likely contact multiple planet gears, the torsional stiffness, or resistance to elastic deformation, is higher in a planetary gear set than parallel axis gear setii. Subcategories this category has the following 4 subcategories, out of 4 total. How to derive and calculate epicyclic gear ratio equations. Zoltan levai 1 described a total of 34 different types of planetary gearsets that can be constructed. Planetary gear reducers belong to the epicyclic family of reducers, since the planet gears trace epicycloidal curves in spacevery similar to how the popular kids toy, the spirograph, worksi.
Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. There is less chance of wheel breakage and no skinned knuckles. A carrier connected to a drive shaft holds the planet gears. The torques on the sun and ring are proportional to their radius. A few of the more common ones are shown in the section below. This block models a gear train with sun, planet, and ring gears. The sun gear drives three planetary gears inside the planetary carrier, which rotate inside the internal ring gear. What are the different types sun gears and planet gears. Optimum distribution of load to each gear is secured by planetary gear system. Temporarily assemble the planet assemblies and intermediate shaft with the rear gasket in the case.
Feb 22, 2017 this video is related to skill education. The twelve illustrated by norton 2 are shown in the planetary oddities page. Typically, the arm and the sun gear will each be driven in some direction at some velocity. Types of planetary gearsets zoltan levai1 described a total of 34 different types of planetary gearsets that can be constructed. The article will discuss the sun and planet gear arrangement of a typical epicyclic gear train and its applications. In this geartrain, inputs and output can be taken from the carrier, ring and sun gears, and only the planet experiences epicyclic motion. The smaller of these gears engages an inner planet gear set, which in turn engages an outer planet gear set. It was invented to bypass the patent on the crank, already held by james pickard. At this time, the sun gear integrated with planet carrier, and the transmission ratio between engine and transmission is one. This video includes working of differential with sun and planet gears. Number 77284k 700r4 or 4l60e patcsonnax power gear. Since the number of planets is a variable in this study, a family of planetary carriers was designed and procured to form 3 to 6planet gear sets.
And it can be wildly used in industry, such as printing lathe, automation assembly. Floating planetary gear bearing arrangements axial location of bearings coated bearings applications in planetary gearboxes pitch and yaw gearbox for wind turbines hydraulic drive unit slewing gear drive for crawler excavators planetary gearbox with frontmounted spur gear stage addresses 00015ce800015ce8 0001771e0001771e 0001771f0001771f. Most of the automatic transmissions use this kind of gear train. The gear ratios between the planetary train members cannot be calculated in the same way as gears trains. Design of machinery an introduction to the synthesis and. For this stage, with the sun as input, planet carrier as output, and the ring gear fixed, the formula is. Because of the planet gears independence it maintains its equilibrium between the carrier and the sun and ring. Lubrication flexibility planetary gear sets may be lubricated with either oil or grease. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which. Supposing a 70% level, crack appears on the sun gear of the first stage, the dynamic response of sun gear and the corresponding fourier spectrum of the gear set are shown in figure 11, respectively. A fast fix for the allison lct heres an alternate method. Remove thrust washer 6b from counterbore in carrier 6a. The sunplanet worm gear block represents a twodegreeoffreedom planetary gear built from carrier, sun, and planet gears. Mechanical efficiency is an important index of gearing, especially for epicyclic gearing.
The production version of the test gear set uses a 6planet carrier. The tshaped key has a pilot and gear teeth that engage teeth on the od of the locking nut. Install the 4x4 extension housing with the c3 planet carrier and output shaft installed. Using sst and a press, remove the differential drive pinion, parking lock gear, counter driven gear with underdrive planetary ring gear and front tapered roller bearing. For clarity, only one planet gear is shown for each type. Using sst, remove the rear tapped roller bearing from the underdrive planetary gear. Murdock also experimented with compressed air and in 1803 constructed a steam gun.
An analyzing method of coupled modes in multistage. Enjoy exclusive discounts and free global delivery on planetary gear reducer at aliexpress. The planet gears perform rotation with the carrier and about the carrier fig. A new nonlinear bendingtorsional coupled model for doublerow planetary gear set was proposed, and planets eccentricity error, static transmission error, and timevarying meshing stiffness were taken into consideration. Planetary gear set of carrier, worm planet, and sun wheels. Modeling and simulation of power coupling system in. Jan 12, 2015 because of the planet gears independence it maintains its equilibrium between the carrier and the sun and ring. Sun gear p planet gear r ring gear a a r m ex ampl e.
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. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. The most basic type of planetary gearset is shown in the figures above. The indicator on the top gear shows we have not yet turned the planets. The engine is used to drive the city bus, individually, and the dynamic property of the city bus is not influenced compared with the traditional city bus. Fault diagnosis for a multistage planetary gear set using. A twostage planetary gear stage is defined using the program.
Say sun has 22 teeth, planet has 27 teeth, ring has 77 teeth,normal module is 1, pressure angle of 20 deg. Since all the three stages in the gear train are identical optimization of one stage is enough for reducing the complexity. Simple planetary gears are arranged with a centrally located, externally toothed sun gear that meshes with one or more externally toothed planet gears. Nut 6p and tanged lockwasher 6n from the planet shaft 6e. Powersplit planetary gear set power calculation physics forums. Planetary gear bearing arrangements in industrial gearboxes. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. The standard adapter keyed washer is replaced by a larger diameter keyed washer with two 14 holes 180 apart. The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines 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 front planet gear controls the gear ratios of first and second gear.
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