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Epicyclic gearing

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planets have "timing marks" (or "relative gear mesh phase" in technical term). The assembly conditions of compound planetary gears are more restrictive than simple planetary gears, and they must be assembled in the correct initial orientation relative to each other, or their teeth will not simultaneously engage the sun and ring gear at opposite ends of the planet, leading to very rough running and short life. In 2015, a traction based variant of the "stepped-planet" design was developed at the Delft University of Technology, which relies on compression of the stepped planet elements to achieve torque transmission. The use of traction elements eliminates the need to "timing marks" as well as the restrictive assembly conditions as typically found. Compound planetary gears can easily achieve larger transmission ratio with equal or smaller volume. For example, compound planets with teeth in a 2:1 ratio with a 50T ring gear would give the same effect as a 100T ring gear, but with half the actual diameter.
163: 5206:. Idler gears are used between sun gear and the planets to cause the sun gear to rotate in the same direction as the ring gear when the planet carrier is stationary. At low input speed, because of the load on the output, the sun will be stationary and the planet carrier will rotate in the direction of the ring gear. Given a high enough load, the turbine of the torque converter will remain stationary, the energy will be dissipated and the torque converter pump will slip. If the input speed is increased to overcome the load the converter turbine will turn the output shaft. Because the torque converter itself is a load on the planet carrier, a force will be exerted on the sun gear. Both the planet carrier and the sun gear extract energy from the system and apply it to the output shaft. 140:, which meshes with the planet gears. Planetary gears (or epicyclic gears) are typically classified as simple or compound planetary gears. Simple planetary gears have one sun, one ring, one carrier, and one planet set. Compound planetary gears involve one or more of the following three types of structures: meshed-planet (there are at least two more planets in mesh with each other in each planet train), stepped-planet (there exists a shaft connection between two planets in each planet train), and multi-stage structures (the system contains two or more planet sets). Compared to simple planetary gears, compound planetary gears have the advantages of larger reduction ratio, higher torque-to-weight ratio, and more flexible configurations. 4596: 5362: 5248:
wear quickly and sometimes crack. But the planetary speed reducer has multiple gear contacting surfaces with a larger area that can distribute the loading evenly around the central axis. Multiple gear surfaces share the load, including any instantaneous impact loading, evenly, which makes them more resistant to damage from higher torque. The housing and bearing parts are also less likely to be damaged from high loading as only the planet carrier bearings experience significant lateral force from the transmission of torque, radial forces oppose each other and are balanced, and axial forces only arise when using helical gears.
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is a convenient way to distinguish the sun gears of the two epicyclic gear trains. Ring gears are normally fixed in most applications as this arrangement will have a good reduction capacity. The second sun gear serves the same purpose as the ring gear of a simple planetary gear train but clearly does
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If one is to create an asymmetric carrier frame with non-equiangular planet gears, say to create some kind of mechanical vibration in the system, one must make the teething such that the above equation complies with the "imaginary gears". For example, in the case where a carrier frame is intended to
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Epicyclic gearing is also available which consists of a sun, a carrier, and two planets which mesh with each other. One planet meshes with the sun gear, while the second planet meshes with the ring gear. For this case, when the carrier is fixed, the ring gear rotates in the same direction as the sun
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In a typical application, the drive power connects to the sun gear. The sun gear then drives the planetary gears assembled with the external gear ring to operate. The whole set of planetary gear system revolves on its own axis and along the external gear ring where the output shaft connected to the
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gear, where a very high reduction ratio in a small package was needed. This had two outer ring gears, each half the thickness of the other gears. One of these two ring gears was held fixed and had one tooth fewer than did the other. Therefore, several turns of the "sun" gear made the "planet" gears
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Some epicyclic gear trains employ two planetary gears which mesh with each other. One of these planets meshes with the sun gear, the other planet meshes with the ring gear. This results in different ratios being generated by the planetary and also causes the sun gear to rotate in the same direction
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Some designs use "stepped-planet" which have two differently-sized gears on either end of a common shaft. The small end engages the sun, while the large end engages the ring gear. This may be necessary to achieve smaller step changes in gear ratio when the overall package size is limited. Compound
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that form epicyclic gear trains to predict the motions of the planets. Accurate predictions of the movement of the Sun, Moon, and the five planets, Mercury, Venus, Mars, Jupiter, and Saturn, across the sky assumed that each followed a trajectory traced by a point on the planet gear of an epicyclic
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The method of motion of a planetary gear structure is different from traditional parallel gears. Traditional gears rely on a small number of contact points between two gears to transfer the driving force. In this case, all the loading is concentrated on a few contacting surfaces, making the gears
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Planetary gear trains provide high power density in comparison to standard parallel axis gear trains. They provide a reduction in volume, multiple kinematic combinations, purely torsional reactions, and coaxial shafting. Disadvantages include high bearing loads, constant lubrication requirements,
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are easy to 3D print, it has become very popular to 3D print a moving herringbone planetary gear system for teaching children how gears work. An advantage of herringbone gears is that they don't fall out of the ring and don't need a mounting plate, allowing the moving parts to be clearly seen.
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In one arrangement, the planetary carrier (green in the diagram above) is held stationary, and the sun gear (yellow) is used as input. In that case, the planetary gears simply rotate about their own axes (i.e., spin) at a rate determined by the number of teeth in each gear. If the sun gear has
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A geared-down motor must turn farther and faster in order to produce the same output movement in the 3D printer which is advantageous if it is not outweighed by the slower movement speed. If the stepper motor has to turn farther then it also has to take more steps to move the printer a given
1629: 3752:— Torque of carrier. For all three, these are the torques applied to the mechanism (input torques). Output torques have the reverse sign of input torques. These torque ratios can be derived using the law of conservation of energy. Applied to a single stage this equation is expressed as: 4185: 4166: 2630: 5339:
distance; therefore, the geared-down stepper motor has a smaller minimum step-size than the same stepper motor without a gearbox. While down-gearing improves precision in unidirectional motion, it adds backlash to the system and so reduces its absolute positioning accuracy.
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The efficiency loss in a planetary gear train is typically about 3% per stage. This type of efficiency ensures that a high proportion (about 97%) of the energy being input is transmitted through the gearbox, rather than being wasted on mechanical losses inside the gearbox.
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The planetary gear train also provides stability due to an even distribution of mass and increased rotational stiffness. Torque applied radially onto the gears of a planetary gear train is transferred radially by the gear, without lateral pressure on the gear teeth.
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The fundamental formula of the planetary gear train with a rotating carrier is obtained by recognizing that this formula remains true if the angular velocities of the sun, planet and ring gears are computed relative to the carrier angular velocity. This becomes,
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mounted so that the center of one gear (the "planet") revolves around the center of the other (the "sun"). A carrier connects the centers of the two gears and rotates, to carry the planet gear(s) around the sun gear. The planet and sun gears mesh so that their
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In epicyclic gears, two speeds must be known in order to determine the third speed. However, in a steady state condition, only one torque must be known in order to determine the other two torques. The equations which determine torque are:
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for a few different reasons. Planetary gear boxes can provide a large gear ratio in a small, light-weight package. Some people install such gearboxes to get more accurate 3D prints by gearing-down the movement of their stepper motors.
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with stationary ring gear and rotating planet carrier as input. Planet gears are extended into cylindrical cutters, rotating around the pencil that is placed on the sun axis. The axes of planetary gears join at the pencil sharpening
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A convenient approach to determine the various speed ratios available in a planetary gear train begins by considering the speed ratio of the gear train when the carrier is held fixed. This is known as the fixed carrier train ratio.
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More planet and sun gear units can be placed in series in the same housing (where the output shaft of the first stage becomes the input shaft of the next stage) providing a larger (or smaller) gear ratio. This is the way most
4570:{\displaystyle {\frac {-\omega _{c}}{\omega _{r}-\omega _{c}}}=R,\quad {\mbox{or}}\quad {\frac {\omega _{r}}{\omega _{c}}}=1-{\frac {1}{R}},\quad {\mbox{so}}\quad {\frac {\omega _{r}}{\omega _{c}}}=1+{\frac {N_{s}}{N_{r}}}.} 3186:{\displaystyle \alpha _{\text{c}}={\frac {{\text{N}}_{\text{s}}}{{\text{N}}_{\text{s}}+{\text{N}}_{\text{r}}}}\alpha _{\text{s}}+{\frac {{\text{N}}_{\text{r}}}{{\text{N}}_{\text{s}}+{\text{N}}_{\text{r}}}}\alpha _{\text{r}}} 500:
of an epicyclic gearing system is somewhat non-intuitive, particularly because there are several ways in which an input rotation can be converted into an output rotation. The four basic components of the epicyclic gear are:
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The load in a planetary gear train is shared among multiple planets; therefore, torque capability is greatly increased. The more planets in the system, the greater the load ability and the higher the torque density.
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More than one member of a system can serve as an output. As an example, the input is connected to the ring gear, the sun gear is connected to the output and the planet carrier is connected to the output through a
4777: 4362:{\displaystyle {\frac {\omega _{s}-\omega _{c}}{-\omega _{c}}}=R,\quad {\mbox{or}}\quad {\frac {\omega _{s}}{\omega _{c}}}=1-R,\quad {\mbox{so}}\quad {\frac {\omega _{s}}{\omega _{c}}}=1+{\frac {N_{r}}{N_{s}}}.} 378: 2401:
The ring gear may also be held fixed, with input provided to the planetary gear carrier; output rotation is then produced from the sun gear. This configuration will produce an increase in gear ratio, equal to
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Each of the speed ratios available to a simple planetary gear train can be obtained by using band brakes to hold and release the carrier, sun or ring gears as needed. This provides the basic structure for an
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is constructed from two identical coaxial epicyclic gear trains assembled with a single carrier such that their planet gears are engaged. This forms a planetary gear train with a fixed carrier train ratio
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of epicyclic gearing with 56-tooth ring gear locked (1), 24-tooth sun gear locked (2), carrier with 16-tooth planetary gears locked (3) and direct drive (4) – numbers denote relative angular speed
3040:{\displaystyle \alpha _{\text{r}}={\frac {{\text{N}}_{\text{s}}+{\text{N}}_{\text{r}}}{{\text{N}}_{\text{r}}}}\alpha _{\text{c}}-{\frac {{\text{N}}_{\text{s}}}{{\text{N}}_{\text{r}}}}\alpha _{\text{s}}} 2911:{\displaystyle \alpha _{\text{s}}={\frac {{\text{N}}_{\text{s}}+{\text{N}}_{\text{r}}}{{\text{N}}_{\text{s}}}}\alpha _{\text{c}}-{\frac {{\text{N}}_{\text{r}}}{{\text{N}}_{\text{s}}}}\alpha _{\text{r}}} 1678: 4998: 2690: 5244:
planetary carrier achieves the goal of speed reduction. A higher reduction ratio can be achieved by doubling the multiple staged gears and planetary gears which can operate within the same ring gear.
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work. In some cases multiple stages may even share the same ring gear which can be extended down the length of the transmission, or even be a structural part of the casing of smaller gearboxes.
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In the case of a simple planetary gear train formed by a carrier supporting a planet gear engaged with a sun and ring gear, the fixed carrier train ratio is computed as the speed ratio of the
2405: 4936: 1721:, receiving power from the system. The ratio of input rotation to output rotation is dependent upon the number of teeth in each of the gears, and upon which component is held stationary. 5999: 5398: 2703:, the sun is usually stationary, being keyed to the axle or even machined directly onto it. The planetary gear carrier is used as input. In this case the gear ratio is simply given by 423: 1511:{\displaystyle \omega _{\text{c}}={\frac {N_{\text{s}}}{\,N_{\text{s}}+N_{\text{r}}\,}}\,\omega _{\text{s}}+{\frac {N_{\text{r}}}{\,N_{\text{s}}+N_{\text{r}}\,}}\,\omega _{\text{r}}} 1711: 619:
The overall gear ratio of a simple planetary gearset can be calculated using the following two equations, representing the sun-planet and planet-ring interactions respectively:
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turns for each turn of the planetary gears. For instance, if the ring gear has 64 teeth, and the planets 16 teeth, one clockwise turn of a planet gear results in
460: 313: 1371:{\displaystyle \omega _{\text{r}}={\frac {\,N_{\text{s}}+N_{\text{r}}\,}{N_{\text{r}}}}\,\omega _{\text{c}}-{\frac {\,N_{\text{s}}\,}{N_{\text{r}}}}\,\omega _{\text{s}}} 3750: 3723: 3696: 488:
contain planet gears spaced 0°, 50°, 120°, and 230°, one is to calculate as if there are actually 36 planetary gears (10° equiangular), rather than the four real ones.
1244:{\displaystyle \omega _{\text{s}}={\frac {\,N_{\text{s}}+N_{\text{r}}\,}{N_{\text{s}}}}\,\omega _{\text{c}}-{\frac {\,N_{\text{r}}\,}{N_{\text{s}}}}\omega _{\text{r}}} 1792: 4599:
A spur gear differential constructed by engaging the planet gears of two co-axial epicyclic gear trains. The casing is the carrier for this planetary gear train.
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These relationships can be used to analyze any epicyclic system, including those, such as hybrid vehicle transmissions, where two of the components are used as
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An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of an outer gear ring, or ring gear, sometimes called an
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Split ring, compound planet, epicyclic gears of a car rear-view mirror positioner. This has a ratio from input sun gear to output black ring gear of −5/352.
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Animation of a printable gear set. Legend: driving shaft and sun gear (green), ring gear (dark gray), planet gears (blue), driven shaft and carrier (red).
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Rotation of the planet gears can in turn drive the ring gear (not depicted in diagram), at a speed corresponding to the gear ratios: If the ring gear has
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In this example, the carrier (green) is held stationary while the sun gear (yellow) is used as input. Analysis assumes a common gear design modulus. The
200:, circa 80 BCE, had gearing which was able to closely match the Moon's elliptical path through the heavens, and even to correct for the nine-year 5153:"Compound planetary gear" is a general concept and it refers to any planetary gears involving one or more of the following three types of structures: 3759: 2510:
If the ring gear is held stationary and the sun gear is used as the input, the planet carrier will be the output. The gear ratio in this case will be
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The red marks show the relative displacement of the sun gear and carrier, when the sun gear is rotated 180° clockwise and the ring gear is held fixed.
4816: 4621: 1624:{\displaystyle -{\frac {\,N_{\text{r}}\,}{N_{\text{s}}}}={\frac {\,\omega _{\text{s}}-\omega _{\text{c}}\,}{\omega _{\text{r}}-\omega _{\text{c}}}}} 5925: 3960: 3870: 266:, a vertically revolving bookstand containing epicyclic gearing with two levels of planetary gears to maintain proper orientation of the books. 5382: 2706: 4782:
Thus, the angular velocity of the carrier of a spur gear differential is the average of the angular velocities of the sun and ring gears.
4710: 321: 6007: 5472: 4161:{\displaystyle {\frac {\omega _{s}}{\omega _{r}}}=R,\quad {\mbox{so}}\quad {\frac {\omega _{s}}{\omega _{r}}}=-{\frac {N_{r}}{N_{s}}}.} 3588: 3440: 3357: 3274: 2625:{\displaystyle \,1/\left(1+{\tfrac {\,N_{\text{r}}\,}{N_{\text{s}}}}\right)={\tfrac {N_{\text{s}}}{\,N_{\text{s}}+N_{\text{r}}\,}}\;,} 2349: 2241: 1727: 2296: 2156: 2024: 1896: 162: 5007: 5074: 4040:
This formula provides a simple way to determine the speed ratios for the simple planetary gear train under different conditions:
1637: 1118:{\displaystyle N_{\text{s}}\,\omega _{\text{s}}+N_{\text{r}}\,\omega _{\text{r}}=(N_{\text{s}}+N_{\text{r}})\,\omega _{\text{c}}} 81:. By choosing to hold one component or another—the planetary carrier, the ring gear, or the sun gear—stationary, three different 4946: 2635: 3523: 3209: 186:
Around 500 BCE, the Greeks invented the idea of epicycles, of circles travelling on the circular orbits. With this theory
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This planetary gear train consists of a sun gear (yellow), planet gears (blue) and carrier (green) inside a ring gear (red)
5751: 6469: 6199: 5434: 5283: 2501:{\displaystyle \;1+{\tfrac {\,N_{\text{r}}\,}{N_{\text{s}}}}={\tfrac {\,N_{\text{s}}+N_{\text{r}}\,}{N_{\text{s}}}}~.} 5799: 5620: 5593: 5309: 17: 5291: 6479: 6179: 5721: 4604: 148: 132:, which itself may rotate relative to the sun gear. Epicyclic gearing systems also incorporate the use of an outer 5911: 4890: 6038: 5149:
with the smaller planet series meshing with the sun wheel and the larger planet series meshing with the ring gear
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This is the lowest gear ratio attainable with an epicyclic gear train. This type of gearing is sometimes used in
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roll without slip. If the sun gear is held fixed, then a point on the pitch circle of the planet gear traces an
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of that path. (The Greeks interpreted the motion they saw, not as elliptical, but rather as epicyclic motion.)
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Miller, John M. (May 2006). "Hybrid electric vehicle propulsion system architectures of the e-CVT type".
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In the cases where gears are accelerating, or to account for friction, these equations must be modified.
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complete a single revolution, which in turn made the rotating ring gear rotate by a single tooth like a
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From the above formulae, we can also derive the accelerations of the sun, ring and carrier, which are:
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In many epicyclic gearing systems, one of these three basic components is held stationary (hence set
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P. A. Simionescu (1998-09-01). "A Unified Approach to the Assembly Condition of Epicyclic Gears".
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For instance, if the sun gear has 24 teeth, and each planet has 16 teeth, then the ratio is
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Alternatively, in the special case where the number of teeth on each gear meets the relationship
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as the ring gear when the planet carrier is the stationary. The fundamental equation becomes:
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In order that the planet gear teeth mesh properly with both the sun and ring gears, assuming
237: 225: 210: 197: 6004: 1880:{\displaystyle n\,\omega _{\text{s}}+(2+n)\,\omega _{\text{r}}-2(1+n)\,\omega _{\text{c}}=0} 6549: 6484: 6242: 5850: 5676: 921:{\displaystyle \omega _{\text{r}},\omega _{\text{s}},\omega _{\text{p}},\omega _{\text{c}}} 5823: 561:(blue) turn in a ratio determined by the number of teeth in each gear. Here, the ratio is 254:, an English abbot of St. Albans monastery, later described epicyclic gearing for an 8: 6574: 6554: 6339: 6086: 6081: 6031: 5854: 5680: 6720: 6625: 6310: 5866: 5692: 5636: 5157:(there are at least two or more planets in mesh with each other in each planet train), 524:(s): Usually two to four peripheral gears, all of the same size, that mesh between the 467: 255: 245: 5824:"How to derive and calculate epicyclic gear ratio equations in planetary gear systems" 5727:(Report). NASA Reference Publication. Vol. 1152. AVSCOM Technical Report 84-C-15. 196:
in 148 CE was able to approximate planetary paths observed crossing the sky. The
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the rate of the sun gear, in the opposite direction. An outer ring gear is not shown.
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gear, thus providing a reversal in direction compared to standard epicyclic gearing.
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One popular use of 3D printed planetary gear systems is as toys for children. Since
77:. Such an assembly of a planet engaging both a sun gear and a ring gear is called a 37: 6589: 6396: 6137: 5893: 5870: 5858: 5684: 5487: 5343: 5219: 5203: 5143: 929: 270: 259: 221: 187: 27:
Two gears mounted so the center of one gear revolves around the center of the other
6609: 6539: 6194: 6091: 6071: 6011: 5926:"52514 Caterpillar Tractor D8 Bulldozer Powershift Transmission Promotional Film" 5440: 5190: 82: 54: 5984: 5979: 5971:, movies and photos of hundreds of working mechanical-systems models at Cornell. 5161:(there exists a shaft connection between two planets in each planet train), and 3864:
formed by the sun, planet and ring gears on the fixed carrier. This is given by
3838:{\displaystyle \tau _{r}\omega _{r}+\tau _{c}\omega _{c}+\tau _{s}\omega _{s}=0} 6779: 6710: 6524: 6519: 6410: 6406: 6204: 6024: 5498: 5461: 2777: 5968: 5809: 5761: 4877:{\displaystyle (R-1)\omega _{\text{c}}=R\omega _{\text{r}}-\omega _{\text{s}}} 4694:{\displaystyle {\frac {\omega _{s}-\omega _{c}}{\omega _{r}-\omega _{c}}}=-1,} 6768: 6753: 6692: 6677: 6657: 6584: 6421: 6391: 6184: 6153: 5989: 5862: 5740:
Revolving Architecture: A history of buildings that rotate, swivel, and pivot
5688: 5214: 4030:{\displaystyle R={\frac {\omega _{s}-\omega _{c}}{\omega _{r}-\omega _{c}}}.} 3940:{\displaystyle R={\frac {\omega _{s}}{\omega _{r}}}=-{\frac {N_{r}}{N_{s}}}.} 1713:
for whichever gear is stationary); one of the two remaining components is an
549:: An outer ring with inward-facing teeth that mesh with the planetary gear(s) 6662: 6599: 6569: 6564: 6158: 5450: 5322: 5181: 4615:
In this case, the fundamental formula for the planetary gear train yields,
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So, with the planetary carrier locked, one turn of the sun gear results in
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clockwise turns of the ring gear. Extending this case from the one above:
240:, circa 80 BCE, to adjust the displayed position of the Moon for the 6743: 6667: 6640: 6635: 6499: 6489: 6305: 6265: 5404:
One of three sets of three gears inside the planet carrier of a Ford FMX
5331: 230: 2762:{\displaystyle {\tfrac {\,N_{\text{s}}+N_{\text{r}}\,}{N_{\text{r}}}}~.} 155:(see below). Further, the sun, planet carrier and ring axes are usually 93: 6725: 6687: 6529: 6362: 6285: 6232: 6189: 6122: 6117: 6066: 5953:
Gears and Their Vibration: A Basic Approach to Understanding Gear Noise
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and construction equipment to provide high torque to the drive wheels.
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equally spaced planet gears, the following equation must be satisfied:
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The axes of all gears are usually parallel, but for special cases like
67: 5974: 5897: 5184:, a special variation of epicyclic gearing was developed for portable 491: 6682: 6672: 6594: 6559: 6315: 6295: 6290: 6112: 6061: 5719: 5504: 263: 166: 5261: 4772:{\displaystyle \omega _{c}={\frac {1}{2}}(\omega _{s}+\omega _{r}).} 6474: 6257: 6247: 6237: 6132: 5466: 5373: 5146: 2700: 2693: 373:{\displaystyle {\frac {N_{\text{s}}+N_{\text{r}}}{n_{\text{p}}}}=A} 216: 192: 5456: 518:
gear(s) symmetrically and separated, all meshed with the sun gear
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not have the internal gear mate that is typical of a ring gear.
3660:{\displaystyle \tau _{s}=-\tau _{c}{\frac {N_{s}}{N_{r}+N_{s}}}} 3512:{\displaystyle \tau _{c}=-\tau _{s}{\frac {N_{r}+N_{s}}{N_{s}}}} 3429:{\displaystyle \tau _{c}=-\tau _{r}{\frac {N_{r}+N_{s}}{N_{r}}}} 3346:{\displaystyle \tau _{r}=-\tau _{c}{\frac {N_{r}}{N_{r}+N_{s}}}} 1717:, providing power to the system, while the last component is an 273:
designed and constructed the first mill with epicycloidal teeth
6645: 6459: 6227: 5994: 5615:(2nd ed.). Oxford, UK: Butterworth-Heinemann. p. 58. 117: 4785:
In discussing the spur gear differential, the use of the term
3196: 2784: 2391:{\displaystyle \;-{\tfrac {\,N_{\text{s}}\,}{N_{\text{r}}}}\;} 2283:{\displaystyle \,-{\tfrac {\,N_{\text{s}}\,}{N_{\text{p}}}}\,} 1779:{\displaystyle \,N_{\text{r}}=N_{\text{s}}+2\,N_{\text{p}}\;,} 128:. Typically, the planet gears are mounted on a movable arm or 6630: 6534: 6331: 5781: 5588:(4th ed.). Cheltenham, UK: Nelson Thornes. p. 244. 5185: 2335:{\displaystyle \,{\tfrac {\,N_{\text{p}}\,}{N_{\text{r}}}}\,} 2195:{\displaystyle \,{\tfrac {\,N_{\text{p}}\,}{N_{\text{r}}}}\,} 2068:{\displaystyle -{\tfrac {\,N_{\text{s}}\,}{N_{\text{p}}}}\;.} 1940:{\displaystyle n={\tfrac {\,N_{\text{s}}\,}{N_{\text{p}}}}\;} 258:
in the 14th century. In 1588, Italian military engineer
5060:{\displaystyle \omega _{\text{r}}=\omega _{\text{c}}(R-1)/R} 2772: 6652: 6047: 5122:{\displaystyle \omega _{\text{s}}=-\omega _{\text{c}}(R-1)} 4793: 1673:{\displaystyle \omega _{\text{r}}\neq \omega _{\text{c}}~.} 109: 58: 4993:{\displaystyle \omega _{\text{r}}=\omega _{\text{s}}(1/R)} 2685:{\displaystyle \;N_{\text{s}}:N_{\text{s}}+N_{\text{r}}~.} 151:, they can be placed at an angle, introducing elements of 6373: 3577:{\displaystyle \tau _{s}=\tau _{r}{\frac {N_{s}}{N_{r}}}} 3263:{\displaystyle \tau _{r}=\tau _{s}{\frac {N_{r}}{N_{s}}}} 6016: 5742:. New York, NY: Princeton Architectural Press. p.  5526: 5524: 5522: 4500: 4445: 4292: 4244: 4094: 3950:
In this calculation the planet gear is an idler gear.
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The number of teeth in the planet gear is irrelevant.
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J. J. Uicker, G. R. Pennock and J. E. Shigley, 2003,
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Kinematic Models for Design Digital Library (KMODDL)
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turns of each of the planet gear(s) about its axis.
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Science and Technology in the Industrial Revolution
5775: 5519: 5507:- a wheel that incorporates a planetary gear system 492:
Gear speed ratios of conventional epicyclic gearing
5783: 5720:Coy, J.J.; Townsend, D.P.; Zaretsky, E.V. (1985). 5653: 5121: 5059: 4992: 4930: 4876: 4771: 4693: 4569: 4361: 4160: 4029: 3939: 3837: 3744: 3717: 3690: 3659: 3576: 3511: 3428: 3345: 3262: 3185: 3039: 2910: 2761: 2684: 2624: 2500: 2390: 2334: 2282: 2194: 2145: 2067: 2013: 1984: 1939: 1879: 1778: 1705: 1672: 1623: 1510: 1370: 1243: 1117: 993: 920: 848: 476: 462:is the number of planet gears in the assembly and 454: 417: 372: 307: 5608: 1786:the equation can be re-written as the following: 6766: 5883: 5955:. Marcel Dekker, New York and MacMillan, London 5840: 5637:"What are planetary gears and how do they work" 5582:"Planetary gearing and unidirectional clutches" 5165:(the system contains two or more planet sets). 5542: 5540: 30:For the ring gear used in starter motors, see 6347: 6032: 5990:The "Interactive Planetary Gearset tutorial" 4931:{\displaystyle R=-N_{\text{r}}/N_{\text{s}}} 3851: 5737: 5548:Kinematics and Dynamics of Planar Machinery 5537: 5290:. Unsourced material may be challenged and 5133: 3197:Torque ratios of standard epicyclic gearing 2785:Accelerations of standard epicyclic gearing 112:system consisting of one or more outer, or 6354: 6340: 6039: 6025: 6005:Short Cuts for Analyzing Planetary Gearing 5940:Gear Drive Systems: Design and Application 5473:NuVinci continuously variable transmission 5431:– ancient mechanical astronomical computer 2639: 2618: 2409: 2387: 2353: 2061: 1936: 1772: 5310:Learn how and when to remove this message 4590: 2738: 2714: 2613: 2589: 2552: 2541: 2517: 2477: 2453: 2431: 2420: 2372: 2361: 2331: 2316: 2305: 2300: 2279: 2264: 2253: 2245: 2191: 2176: 2165: 2160: 2142: 2131: 2046: 2035: 2010: 1999: 1981: 1970: 1921: 1910: 1860: 1828: 1799: 1761: 1731: 1592: 1568: 1548: 1537: 1497: 1493: 1469: 1442: 1438: 1414: 1357: 1343: 1332: 1315: 1301: 1277: 1217: 1206: 1189: 1175: 1151: 1104: 1061: 1037: 821: 774: 750: 715: 709: 667: 643: 599:; meaning that each planet gear turns at 418:{\displaystyle N_{\text{s}},N_{\text{r}}} 5782:Musson, A.E.; Robinson, Eric H. (1969). 5662:"The Antikythera Mechanism reconsidered" 5586:Fundamentals of Motor Vehicle Technology 5321: 5228:inaccessibility, and design complexity. 5213: 5137: 4797: 4794:Gear ratio of reversed epicyclic gearing 4594: 2771: 1017:from which we can derive the following: 552: 161: 92: 36: 5579: 5453:– had a 2 speed planetary transmission. 5330:Planetary gears have become popular in 2117:turn of the sun gear produces 1.5  14: 6767: 5843:IEEE Transactions on Power Electronics 5659: 1706:{\displaystyle \omega _{\text{...}}=0} 6335: 6020: 5715: 5713: 2293:One turn of a planet gear results in 5975:"Epicyclic gearing animation in SVG" 5609:Harrison, H.; Nettleton, T. (1994). 5288:adding citations to reliable sources 5255: 2238:One turn of the sun gear results in 2153:teeth, then the ring will rotate by 229:gear train. This curve is called an 207:In the 2nd century AD treatise 5612:Principles of Engineering Mechanics 24: 6470:Continuously variable transmission 6200:Continuously variable transmission 5710: 5534:Oxford University Press, New York. 5532:Theory of Machines and Mechanisms, 5435:Continuously variable transmission 5196: 2780:AM bicycle hub (ring gear removed) 2021:teeth, then the ratio is equal to 269:French mathematician and engineer 236:Epicyclic gearing was used in the 25: 6791: 5962: 5669:Interdisciplinary Science Reviews 4173:2. The ring gear is held fixed, ω 284:Requirements for non-interference 6749: 6748: 6738: 5980:"Animation of Epicyclic gearing" 5397: 5381: 5372: 5360: 5260: 4374:3. The sun gear is held fixed, ω 2146:{\displaystyle \,N_{\text{r}}\,} 2014:{\displaystyle \,N_{\text{p}}\,} 1992:teeth, and each planet gear has 1985:{\displaystyle \,N_{\text{s}}\,} 1947:is the sun-to-planet gear ratio. 5945: 5932: 5918: 5904: 5816: 4506: 4498: 4451: 4443: 4298: 4290: 4250: 4242: 4100: 4092: 4043:1. The carrier is held fixed, ω 1001:are the number of teeth of the 425:are the number of teeth of the 171:Le diverse et artifiose machine 6361: 5731: 5629: 5602: 5573: 5553: 5490:– 14-ratio bicycle hub gearbox 5390:Pratt & Whitney Canada PT6 5251: 5116: 5104: 5046: 5034: 4987: 4973: 4832: 4820: 4763: 4737: 1857: 1845: 1825: 1813: 1101: 1075: 13: 1: 6505:Automated manual transmission 6077:Epicyclic (planetary) gearing 5641:Power Transmission Components 5512: 5209: 5147:internally geared bicycle hub 5142:Stepped planet series of the 5129:when the ring gear is locked. 2632:which may also be written as 274: 5886:Journal of Mechanical Design 5478:Ravigneaux planetary gearset 3698:— Torque of ring (annulus), 1959:relative to the two inputs. 455:{\displaystyle n_{\text{p}}} 308:{\displaystyle n_{\text{p}}} 120:, revolving about a central 7: 6580:Semi-automatic transmission 5738:Randl, Chad (15 May 2008). 5416: 5000:when the carrier is locked, 244:, and even for its orbital 88: 57:assembly consisting of two 10: 6796: 6417:Internal combustion engine 5483:Lepelletier gear mechanism 5350: 181: 169:, from Agostino Ramelli's 29: 6734: 6716:Hybrid vehicle drivetrain 6703: 6618: 6605:Transmission control unit 6545:Limited-slip differential 6510:Electrorheological clutch 6435: 6382: 6369: 6321:Spur gear corrected tooth 6278: 6256: 6220: 6213: 6167: 6146: 6105: 6054: 6046: 5942:. Marcel Dekker, New York 5494:Simpson planetary gearset 3852:Fixed carrier train ratio 3745:{\displaystyle \tau _{c}} 3718:{\displaystyle \tau _{s}} 3691:{\displaystyle \tau _{r}} 1955:with the third providing 6495:Dual-clutch transmission 5985:The "Power Split Device" 5863:10.1109/TPEL.2006.872372 5689:10.1179/030801807X163670 5580:Hillier, V.A.W. (2001). 5567:University of California 5134:Compound planetary gears 2398:turns of the ring gear. 242:ellipticity of its orbit 6465:Constant-velocity joint 5175:automatic transmissions 5067:when the sun is locked, 6445:Automatic transmission 5327: 5224: 5163:multi-stage structures 5150: 5123: 5061: 4994: 4932: 4878: 4806: 4773: 4695: 4605:spur gear differential 4600: 4591:Spur gear differential 4585:automatic transmission 4571: 4363: 4162: 4031: 3941: 3839: 3746: 3719: 3692: 3661: 3578: 3513: 3430: 3347: 3264: 3187: 3041: 2912: 2781: 2776:Compound planets of a 2763: 2686: 2626: 2502: 2392: 2342:turns of the ring gear 2336: 2284: 2196: 2147: 2113:; this means that one 2069: 2015: 1986: 1941: 1881: 1780: 1707: 1674: 1625: 1512: 1372: 1245: 1119: 995: 922: 850: 616: 478: 456: 419: 374: 309: 252:Richard of Wallingford 226:deferent and epicycles 174: 98: 42: 5938:Lynwander, P., 1983, 5660:Wright, M.T. (2007). 5429:Antikythera mechanism 5424:Hypocycloidal gearing 5325: 5217: 5141: 5124: 5062: 4995: 4933: 4879: 4801: 4774: 4696: 4598: 4572: 4364: 4163: 4032: 3942: 3840: 3747: 3720: 3693: 3662: 3579: 3514: 3431: 3348: 3265: 3188: 3042: 2913: 2775: 2764: 2687: 2627: 2503: 2393: 2337: 2285: 2197: 2148: 2070: 2016: 1987: 1942: 1882: 1781: 1708: 1675: 1626: 1513: 1373: 1246: 1120: 996: 923: 851: 556: 479: 457: 420: 375: 310: 238:Antikythera Mechanism 211:Mathematical Syntaxis 198:Antikythera Mechanism 165: 96: 40: 6550:Locking differential 6485:Direct-shift gearbox 6243:Shaft-driven bicycle 5951:Smith, J. D., 1983, 5569:. 1913. p. 979. 5562:Machinery, Volume 19 5469:, for bicycles, etc. 5284:improve this section 5075: 5008: 4947: 4891: 4817: 4711: 4622: 4387: 4186: 4056: 3961: 3871: 3760: 3729: 3702: 3675: 3589: 3524: 3441: 3358: 3275: 3210: 3054: 2925: 2796: 2707: 2636: 2514: 2406: 2350: 2297: 2290:turns of the planets 2242: 2157: 2128: 2025: 1996: 1967: 1897: 1793: 1728: 1684: 1638: 1528: 1385: 1258: 1132: 1024: 952: 866: 626: 514:: Holds one or more 468: 439: 389: 322: 292: 79:planetary gear train 47:epicyclic gear train 6775:Epicyclical gearing 6575:Preselector gearbox 6555:Manual transmission 6082:Sun and planet gear 5855:2006ITPE...21..756M 5681:2007ISRv...32...27W 5392:gas turbine engine. 5388:Reduction gears on 5218:The mechanism of a 433:, respectively and 6721:Electric generator 6626:Wheel hub assembly 6311:Gear manufacturing 6147:Geartooth profiles 6010:2021-02-25 at the 5912:"Archimedes Drive" 5328: 5225: 5151: 5119: 5057: 4990: 4940:which results in: 4928: 4874: 4807: 4769: 4691: 4601: 4567: 4504: 4449: 4359: 4296: 4248: 4158: 4098: 4027: 3937: 3835: 3742: 3715: 3688: 3657: 3574: 3509: 3426: 3343: 3260: 3183: 3037: 2908: 2782: 2759: 2751: 2682: 2622: 2616: 2565: 2498: 2490: 2444: 2388: 2385: 2332: 2329: 2280: 2277: 2192: 2189: 2143: 2065: 2059: 2011: 1982: 1937: 1934: 1877: 1776: 1703: 1670: 1621: 1508: 1368: 1241: 1115: 991: 948:respectively, and 930:angular velocities 918: 846: 844: 617: 508:: The central gear 484:is a whole number 474: 452: 415: 370: 305: 256:astronomical clock 246:apsidal precession 175: 99: 43: 6762: 6761: 6515:Epicyclic gearing 6384:Automotive engine 6329: 6328: 6274: 6273: 6097:Non-circular gear 6062:Spur gear systems 6000:Planetary Gearbox 5928:. 10 August 2022. 5898:10.1115/1.2829172 5344:herringbone gears 5320: 5319: 5312: 5101: 5085: 5031: 5018: 4970: 4957: 4925: 4910: 4871: 4858: 4842: 4735: 4677: 4612: = −1. 4562: 4529: 4503: 4493: 4474: 4448: 4432: 4354: 4321: 4295: 4273: 4247: 4231: 4153: 4123: 4097: 4081: 4022: 3932: 3902: 3725:— Torque of sun, 3655: 3572: 3507: 3424: 3341: 3258: 3180: 3171: 3167: 3162: 3152: 3147: 3139: 3134: 3122: 3113: 3109: 3104: 3094: 3089: 3081: 3076: 3064: 3034: 3025: 3022: 3017: 3010: 3005: 2993: 2984: 2981: 2976: 2968: 2963: 2953: 2948: 2935: 2905: 2896: 2893: 2888: 2881: 2876: 2864: 2855: 2852: 2847: 2839: 2834: 2824: 2819: 2806: 2755: 2750: 2747: 2735: 2722: 2678: 2673: 2660: 2647: 2615: 2610: 2597: 2585: 2564: 2561: 2549: 2494: 2489: 2486: 2474: 2461: 2443: 2440: 2428: 2384: 2381: 2369: 2328: 2325: 2313: 2276: 2273: 2261: 2188: 2185: 2173: 2139: 2058: 2055: 2043: 2007: 1978: 1933: 1930: 1918: 1868: 1836: 1807: 1769: 1752: 1739: 1694: 1666: 1661: 1648: 1619: 1615: 1602: 1589: 1576: 1560: 1557: 1545: 1505: 1495: 1490: 1477: 1465: 1450: 1440: 1435: 1422: 1410: 1395: 1365: 1355: 1352: 1340: 1323: 1313: 1310: 1298: 1285: 1268: 1238: 1229: 1226: 1214: 1197: 1187: 1184: 1172: 1159: 1142: 1112: 1098: 1085: 1069: 1058: 1045: 1034: 988: 975: 962: 915: 902: 889: 876: 829: 813: 800: 782: 771: 758: 747: 723: 706: 693: 675: 664: 651: 640: 477:{\displaystyle A} 449: 412: 399: 362: 359: 348: 335: 302: 145:pencil sharpeners 106:planetary gearing 102:Epicyclic gearing 85:can be realized. 51:planetary gearset 49:(also known as a 32:Starter ring gear 18:Planetary gearbox 16:(Redirected from 6787: 6752: 6751: 6742: 6619:Wheels and tires 6590:Torque converter 6356: 6349: 6342: 6333: 6332: 6218: 6217: 6041: 6034: 6027: 6018: 6017: 5956: 5949: 5943: 5936: 5930: 5929: 5922: 5916: 5915: 5908: 5902: 5901: 5881: 5875: 5874: 5838: 5832: 5831: 5820: 5814: 5813: 5789: 5779: 5773: 5765: 5735: 5729: 5728: 5726: 5717: 5708: 5707: 5705: 5703: 5666: 5657: 5651: 5650: 5648: 5647: 5633: 5627: 5626: 5606: 5600: 5599: 5577: 5571: 5570: 5557: 5551: 5550:, Prentice Hall. 5544: 5535: 5528: 5488:Rohloff Speedhub 5401: 5385: 5376: 5364: 5315: 5308: 5304: 5301: 5295: 5264: 5256: 5220:pencil sharpener 5204:torque converter 5144:Rohloff Speedhub 5128: 5126: 5125: 5120: 5103: 5102: 5099: 5087: 5086: 5083: 5066: 5064: 5063: 5058: 5053: 5033: 5032: 5029: 5020: 5019: 5016: 4999: 4997: 4996: 4991: 4983: 4972: 4971: 4968: 4959: 4958: 4955: 4937: 4935: 4934: 4929: 4927: 4926: 4923: 4917: 4912: 4911: 4908: 4883: 4881: 4880: 4875: 4873: 4872: 4869: 4860: 4859: 4856: 4844: 4843: 4840: 4778: 4776: 4775: 4770: 4762: 4761: 4749: 4748: 4736: 4728: 4723: 4722: 4700: 4698: 4697: 4692: 4678: 4676: 4675: 4674: 4662: 4661: 4651: 4650: 4649: 4637: 4636: 4626: 4576: 4574: 4573: 4568: 4563: 4561: 4560: 4551: 4550: 4541: 4530: 4528: 4527: 4518: 4517: 4508: 4505: 4501: 4494: 4486: 4475: 4473: 4472: 4463: 4462: 4453: 4450: 4446: 4433: 4431: 4430: 4429: 4417: 4416: 4406: 4405: 4404: 4391: 4368: 4366: 4365: 4360: 4355: 4353: 4352: 4343: 4342: 4333: 4322: 4320: 4319: 4310: 4309: 4300: 4297: 4293: 4274: 4272: 4271: 4262: 4261: 4252: 4249: 4245: 4232: 4230: 4229: 4228: 4215: 4214: 4213: 4201: 4200: 4190: 4167: 4165: 4164: 4159: 4154: 4152: 4151: 4142: 4141: 4132: 4124: 4122: 4121: 4112: 4111: 4102: 4099: 4095: 4082: 4080: 4079: 4070: 4069: 4060: 4036: 4034: 4033: 4028: 4023: 4021: 4020: 4019: 4007: 4006: 3996: 3995: 3994: 3982: 3981: 3971: 3946: 3944: 3943: 3938: 3933: 3931: 3930: 3921: 3920: 3911: 3903: 3901: 3900: 3891: 3890: 3881: 3844: 3842: 3841: 3836: 3828: 3827: 3818: 3817: 3805: 3804: 3795: 3794: 3782: 3781: 3772: 3771: 3751: 3749: 3748: 3743: 3741: 3740: 3724: 3722: 3721: 3716: 3714: 3713: 3697: 3695: 3694: 3689: 3687: 3686: 3666: 3664: 3663: 3658: 3656: 3654: 3653: 3652: 3640: 3639: 3629: 3628: 3619: 3617: 3616: 3601: 3600: 3583: 3581: 3580: 3575: 3573: 3571: 3570: 3561: 3560: 3551: 3549: 3548: 3536: 3535: 3518: 3516: 3515: 3510: 3508: 3506: 3505: 3496: 3495: 3494: 3482: 3481: 3471: 3469: 3468: 3453: 3452: 3435: 3433: 3432: 3427: 3425: 3423: 3422: 3413: 3412: 3411: 3399: 3398: 3388: 3386: 3385: 3370: 3369: 3352: 3350: 3349: 3344: 3342: 3340: 3339: 3338: 3326: 3325: 3315: 3314: 3305: 3303: 3302: 3287: 3286: 3269: 3267: 3266: 3261: 3259: 3257: 3256: 3247: 3246: 3237: 3235: 3234: 3222: 3221: 3192: 3190: 3189: 3184: 3182: 3181: 3178: 3172: 3170: 3169: 3168: 3165: 3163: 3160: 3154: 3153: 3150: 3148: 3145: 3141: 3140: 3137: 3135: 3132: 3129: 3124: 3123: 3120: 3114: 3112: 3111: 3110: 3107: 3105: 3102: 3096: 3095: 3092: 3090: 3087: 3083: 3082: 3079: 3077: 3074: 3071: 3066: 3065: 3062: 3046: 3044: 3043: 3038: 3036: 3035: 3032: 3026: 3024: 3023: 3020: 3018: 3015: 3012: 3011: 3008: 3006: 3003: 3000: 2995: 2994: 2991: 2985: 2983: 2982: 2979: 2977: 2974: 2971: 2970: 2969: 2966: 2964: 2961: 2955: 2954: 2951: 2949: 2946: 2942: 2937: 2936: 2933: 2917: 2915: 2914: 2909: 2907: 2906: 2903: 2897: 2895: 2894: 2891: 2889: 2886: 2883: 2882: 2879: 2877: 2874: 2871: 2866: 2865: 2862: 2856: 2854: 2853: 2850: 2848: 2845: 2842: 2841: 2840: 2837: 2835: 2832: 2826: 2825: 2822: 2820: 2817: 2813: 2808: 2807: 2804: 2768: 2766: 2765: 2760: 2753: 2752: 2749: 2748: 2745: 2739: 2737: 2736: 2733: 2724: 2723: 2720: 2712: 2691: 2689: 2688: 2683: 2676: 2675: 2674: 2671: 2662: 2661: 2658: 2649: 2648: 2645: 2631: 2629: 2628: 2623: 2617: 2614: 2612: 2611: 2608: 2599: 2598: 2595: 2587: 2586: 2583: 2577: 2571: 2567: 2566: 2563: 2562: 2559: 2553: 2551: 2550: 2547: 2539: 2525: 2507: 2505: 2504: 2499: 2492: 2491: 2488: 2487: 2484: 2478: 2476: 2475: 2472: 2463: 2462: 2459: 2451: 2445: 2442: 2441: 2438: 2432: 2430: 2429: 2426: 2418: 2397: 2395: 2394: 2389: 2386: 2383: 2382: 2379: 2373: 2371: 2370: 2367: 2359: 2341: 2339: 2338: 2333: 2330: 2327: 2326: 2323: 2317: 2315: 2314: 2311: 2303: 2289: 2287: 2286: 2281: 2278: 2275: 2274: 2271: 2265: 2263: 2262: 2259: 2251: 2233: 2231: 2230: 2227: 2224: 2217: 2215: 2214: 2211: 2208: 2201: 2199: 2198: 2193: 2190: 2187: 2186: 2183: 2177: 2175: 2174: 2171: 2163: 2152: 2150: 2149: 2144: 2141: 2140: 2137: 2119:counterclockwise 2112: 2110: 2109: 2106: 2103: 2099: 2093: 2091: 2090: 2087: 2084: 2080: 2074: 2072: 2071: 2066: 2060: 2057: 2056: 2053: 2047: 2045: 2044: 2041: 2033: 2020: 2018: 2017: 2012: 2009: 2008: 2005: 1991: 1989: 1988: 1983: 1980: 1979: 1976: 1946: 1944: 1943: 1938: 1935: 1932: 1931: 1928: 1922: 1920: 1919: 1916: 1908: 1886: 1884: 1883: 1878: 1870: 1869: 1866: 1838: 1837: 1834: 1809: 1808: 1805: 1785: 1783: 1782: 1777: 1771: 1770: 1767: 1754: 1753: 1750: 1741: 1740: 1737: 1712: 1710: 1709: 1704: 1696: 1695: 1692: 1679: 1677: 1676: 1671: 1664: 1663: 1662: 1659: 1650: 1649: 1646: 1630: 1628: 1627: 1622: 1620: 1618: 1617: 1616: 1613: 1604: 1603: 1600: 1593: 1591: 1590: 1587: 1578: 1577: 1574: 1566: 1561: 1559: 1558: 1555: 1549: 1547: 1546: 1543: 1535: 1517: 1515: 1514: 1509: 1507: 1506: 1503: 1496: 1494: 1492: 1491: 1488: 1479: 1478: 1475: 1467: 1466: 1463: 1457: 1452: 1451: 1448: 1441: 1439: 1437: 1436: 1433: 1424: 1423: 1420: 1412: 1411: 1408: 1402: 1397: 1396: 1393: 1377: 1375: 1374: 1369: 1367: 1366: 1363: 1356: 1354: 1353: 1350: 1344: 1342: 1341: 1338: 1330: 1325: 1324: 1321: 1314: 1312: 1311: 1308: 1302: 1300: 1299: 1296: 1287: 1286: 1283: 1275: 1270: 1269: 1266: 1250: 1248: 1247: 1242: 1240: 1239: 1236: 1230: 1228: 1227: 1224: 1218: 1216: 1215: 1212: 1204: 1199: 1198: 1195: 1188: 1186: 1185: 1182: 1176: 1174: 1173: 1170: 1161: 1160: 1157: 1149: 1144: 1143: 1140: 1124: 1122: 1121: 1116: 1114: 1113: 1110: 1100: 1099: 1096: 1087: 1086: 1083: 1071: 1070: 1067: 1060: 1059: 1056: 1047: 1046: 1043: 1036: 1035: 1032: 1000: 998: 997: 992: 990: 989: 986: 977: 976: 973: 964: 963: 960: 927: 925: 924: 919: 917: 916: 913: 904: 903: 900: 891: 890: 887: 878: 877: 874: 855: 853: 852: 847: 845: 831: 830: 827: 820: 816: 815: 814: 811: 802: 801: 798: 784: 783: 780: 773: 772: 769: 760: 759: 756: 749: 748: 745: 725: 724: 721: 714: 710: 708: 707: 704: 695: 694: 691: 677: 676: 673: 666: 665: 662: 653: 652: 649: 642: 641: 638: 614: 612: 611: 608: 605: 598: 596: 595: 592: 589: 585: 579: 577: 576: 573: 570: 566: 483: 481: 480: 475: 461: 459: 458: 453: 451: 450: 447: 424: 422: 421: 416: 414: 413: 410: 401: 400: 397: 379: 377: 376: 371: 363: 361: 360: 357: 351: 350: 349: 346: 337: 336: 333: 326: 314: 312: 311: 306: 304: 303: 300: 279: 276: 260:Agostino Ramelli 222:Claudius Ptolemy 188:Claudius Ptolemy 21: 6795: 6794: 6790: 6789: 6788: 6786: 6785: 6784: 6765: 6764: 6763: 6758: 6730: 6699: 6614: 6610:Universal joint 6540:Hotchkiss drive 6431: 6378: 6365: 6360: 6330: 6325: 6270: 6252: 6209: 6195:Bicycle gearing 6163: 6142: 6101: 6092:Cycloidal drive 6072:Rack and pinion 6050: 6045: 6012:Wayback Machine 5965: 5960: 5959: 5950: 5946: 5937: 5933: 5924: 5923: 5919: 5910: 5909: 5905: 5882: 5878: 5839: 5835: 5822: 5821: 5817: 5802: 5780: 5776: 5754: 5753:978-156898681-4 5736: 5732: 5724: 5718: 5711: 5701: 5699: 5664: 5658: 5654: 5645: 5643: 5635: 5634: 5630: 5623: 5607: 5603: 5596: 5578: 5574: 5559: 5558: 5554: 5546:B. Paul, 1979, 5545: 5538: 5529: 5520: 5515: 5510: 5441:Cycloidal drive 5419: 5414: 5413: 5412: 5409: 5402: 5393: 5386: 5377: 5368: 5365: 5353: 5316: 5305: 5299: 5296: 5281: 5265: 5254: 5212: 5199: 5197:Power splitting 5191:cycloidal drive 5136: 5098: 5094: 5082: 5078: 5076: 5073: 5072: 5049: 5028: 5024: 5015: 5011: 5009: 5006: 5005: 4979: 4967: 4963: 4954: 4950: 4948: 4945: 4944: 4922: 4918: 4913: 4907: 4903: 4892: 4889: 4888: 4868: 4864: 4855: 4851: 4839: 4835: 4818: 4815: 4814: 4796: 4757: 4753: 4744: 4740: 4727: 4718: 4714: 4712: 4709: 4708: 4670: 4666: 4657: 4653: 4652: 4645: 4641: 4632: 4628: 4627: 4625: 4623: 4620: 4619: 4593: 4556: 4552: 4546: 4542: 4540: 4523: 4519: 4513: 4509: 4507: 4499: 4485: 4468: 4464: 4458: 4454: 4452: 4444: 4425: 4421: 4412: 4408: 4407: 4400: 4396: 4392: 4390: 4388: 4385: 4384: 4377: 4348: 4344: 4338: 4334: 4332: 4315: 4311: 4305: 4301: 4299: 4291: 4267: 4263: 4257: 4253: 4251: 4243: 4224: 4220: 4216: 4209: 4205: 4196: 4192: 4191: 4189: 4187: 4184: 4183: 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1255: 1235: 1231: 1223: 1219: 1211: 1207: 1205: 1203: 1194: 1190: 1181: 1177: 1169: 1165: 1156: 1152: 1150: 1148: 1139: 1135: 1133: 1130: 1129: 1109: 1105: 1095: 1091: 1082: 1078: 1066: 1062: 1055: 1051: 1042: 1038: 1031: 1027: 1025: 1022: 1021: 985: 981: 972: 968: 959: 955: 953: 950: 949: 942:planetary gears 912: 908: 899: 895: 886: 882: 873: 869: 867: 864: 863: 843: 842: 832: 826: 822: 810: 806: 797: 793: 792: 788: 779: 775: 768: 764: 755: 751: 744: 740: 737: 736: 726: 720: 716: 703: 699: 690: 686: 685: 681: 672: 668: 661: 657: 648: 644: 637: 633: 629: 627: 624: 623: 609: 606: 603: 602: 600: 593: 590: 587: 586: 583: 581: 574: 571: 568: 567: 564: 562: 559:planetary gears 494: 469: 466: 465: 446: 442: 440: 437: 436: 409: 405: 396: 392: 390: 387: 386: 356: 352: 345: 341: 332: 328: 327: 325: 323: 320: 319: 299: 295: 293: 290: 289: 286: 277: 184: 91: 35: 28: 23: 22: 15: 12: 11: 5: 6793: 6783: 6782: 6777: 6760: 6759: 6757: 6756: 6746: 6735: 6732: 6731: 6729: 6728: 6723: 6718: 6713: 6711:Electric motor 6707: 6705: 6701: 6700: 6698: 6697: 6696: 6695: 6690: 6685: 6680: 6675: 6670: 6665: 6660: 6650: 6649: 6648: 6643: 6638: 6628: 6622: 6620: 6616: 6615: 6613: 6612: 6607: 6602: 6597: 6592: 6587: 6582: 6577: 6572: 6567: 6562: 6557: 6552: 6547: 6542: 6537: 6532: 6527: 6525:Friction drive 6522: 6520:Fluid coupling 6517: 6512: 6507: 6502: 6497: 6492: 6487: 6482: 6477: 6472: 6467: 6462: 6457: 6452: 6447: 6441: 6439: 6433: 6432: 6430: 6429: 6424: 6419: 6414: 6411:Plug-in hybrid 6404: 6399: 6394: 6388: 6386: 6380: 6379: 6370: 6367: 6366: 6359: 6358: 6351: 6344: 6336: 6327: 6326: 6324: 6323: 6318: 6313: 6308: 6303: 6298: 6293: 6288: 6282: 6280: 6276: 6275: 6272: 6271: 6269: 6268: 6262: 6260: 6254: 6253: 6251: 6250: 6245: 6240: 6235: 6230: 6224: 6222: 6215: 6211: 6210: 6208: 6207: 6202: 6197: 6192: 6187: 6182: 6177: 6171: 6169: 6165: 6164: 6162: 6161: 6156: 6150: 6148: 6144: 6143: 6141: 6140: 6135: 6130: 6125: 6120: 6115: 6109: 6107: 6103: 6102: 6100: 6099: 6094: 6089: 6087:Harmonic drive 6084: 6079: 6074: 6069: 6064: 6058: 6056: 6052: 6051: 6044: 6043: 6036: 6029: 6021: 6015: 6014: 6002: 5997: 5992: 5987: 5982: 5977: 5972: 5964: 5963:External links 5961: 5958: 5957: 5944: 5931: 5917: 5903: 5892:(3): 448–453. 5876: 5849:(3): 756–767. 5833: 5815: 5800: 5774: 5752: 5730: 5709: 5652: 5628: 5621: 5601: 5594: 5572: 5552: 5536: 5517: 5516: 5514: 5511: 5509: 5508: 5502: 5499:Sturmey Archer 5496: 5491: 5485: 5480: 5475: 5470: 5464: 5462:Harmonic drive 5459: 5454: 5448: 5443: 5438: 5432: 5426: 5420: 5418: 5415: 5411: 5410: 5403: 5396: 5394: 5387: 5380: 5378: 5371: 5369: 5366: 5359: 5356: 5355: 5354: 5352: 5349: 5318: 5317: 5268: 5266: 5259: 5253: 5250: 5211: 5208: 5198: 5195: 5159:stepped-planet 5135: 5132: 5131: 5130: 5118: 5115: 5112: 5109: 5106: 5097: 5093: 5090: 5081: 5069: 5068: 5056: 5052: 5048: 5045: 5042: 5039: 5036: 5027: 5023: 5014: 5002: 5001: 4989: 4986: 4982: 4978: 4975: 4966: 4962: 4953: 4921: 4916: 4906: 4902: 4899: 4896: 4885: 4884: 4867: 4863: 4854: 4850: 4847: 4838: 4834: 4831: 4828: 4825: 4822: 4803:CSS animations 4795: 4792: 4780: 4779: 4768: 4765: 4760: 4756: 4752: 4747: 4743: 4739: 4734: 4731: 4726: 4721: 4717: 4702: 4701: 4690: 4687: 4684: 4681: 4673: 4669: 4665: 4660: 4656: 4648: 4644: 4640: 4635: 4631: 4592: 4589: 4580: 4579: 4578: 4577: 4566: 4559: 4555: 4549: 4545: 4539: 4536: 4533: 4526: 4522: 4516: 4512: 4497: 4492: 4489: 4484: 4481: 4478: 4471: 4467: 4461: 4457: 4442: 4439: 4436: 4428: 4424: 4420: 4415: 4411: 4403: 4399: 4395: 4375: 4372: 4371: 4370: 4369: 4358: 4351: 4347: 4341: 4337: 4331: 4328: 4325: 4318: 4314: 4308: 4304: 4289: 4286: 4283: 4280: 4277: 4270: 4266: 4260: 4256: 4241: 4238: 4235: 4227: 4223: 4219: 4212: 4208: 4204: 4199: 4195: 4174: 4171: 4170: 4169: 4168: 4157: 4150: 4146: 4140: 4136: 4130: 4127: 4120: 4116: 4110: 4106: 4091: 4088: 4085: 4078: 4074: 4068: 4064: 4044: 4038: 4037: 4026: 4018: 4014: 4010: 4005: 4001: 3993: 3989: 3985: 3980: 3976: 3969: 3966: 3948: 3947: 3936: 3929: 3925: 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763: 754: 743: 739: 738: 735: 732: 729: 727: 719: 713: 702: 698: 689: 684: 680: 671: 660: 656: 647: 636: 632: 631: 551: 550: 532: 519: 509: 493: 490: 473: 445: 408: 404: 395: 381: 380: 369: 366: 355: 344: 340: 331: 298: 285: 282: 224:used rotating 183: 180: 90: 87: 55:gear reduction 26: 9: 6: 4: 3: 2: 6792: 6781: 6778: 6776: 6773: 6772: 6770: 6755: 6747: 6745: 6741: 6737: 6736: 6733: 6727: 6724: 6722: 6719: 6717: 6714: 6712: 6709: 6708: 6706: 6702: 6694: 6691: 6689: 6686: 6684: 6681: 6679: 6676: 6674: 6671: 6669: 6666: 6664: 6661: 6659: 6656: 6655: 6654: 6651: 6647: 6644: 6642: 6639: 6637: 6634: 6633: 6632: 6629: 6627: 6624: 6623: 6621: 6617: 6611: 6608: 6606: 6603: 6601: 6598: 6596: 6593: 6591: 6588: 6586: 6585:Shift-by-wire 6583: 6581: 6578: 6576: 6573: 6571: 6568: 6566: 6563: 6561: 6558: 6556: 6553: 6551: 6548: 6546: 6543: 6541: 6538: 6536: 6533: 6531: 6528: 6526: 6523: 6521: 6518: 6516: 6513: 6511: 6508: 6506: 6503: 6501: 6498: 6496: 6493: 6491: 6488: 6486: 6483: 6481: 6478: 6476: 6473: 6471: 6468: 6466: 6463: 6461: 6458: 6456: 6453: 6451: 6448: 6446: 6443: 6442: 6440: 6438: 6434: 6428: 6425: 6423: 6422:Petrol engine 6420: 6418: 6415: 6412: 6408: 6405: 6403: 6400: 6398: 6395: 6393: 6392:Diesel engine 6390: 6389: 6387: 6385: 6381: 6377: 6375: 6368: 6364: 6357: 6352: 6350: 6345: 6343: 6338: 6337: 6334: 6322: 6319: 6317: 6314: 6312: 6309: 6307: 6304: 6302: 6299: 6297: 6294: 6292: 6289: 6287: 6284: 6283: 6281: 6277: 6267: 6264: 6263: 6261: 6259: 6255: 6249: 6246: 6244: 6241: 6239: 6236: 6234: 6231: 6229: 6226: 6225: 6223: 6219: 6216: 6212: 6206: 6203: 6201: 6198: 6196: 6193: 6191: 6188: 6186: 6183: 6181: 6178: 6176: 6173: 6172: 6170: 6166: 6160: 6157: 6155: 6152: 6151: 6149: 6145: 6139: 6136: 6134: 6131: 6129: 6126: 6124: 6121: 6119: 6116: 6114: 6111: 6110: 6108: 6104: 6098: 6095: 6093: 6090: 6088: 6085: 6083: 6080: 6078: 6075: 6073: 6070: 6068: 6065: 6063: 6060: 6059: 6057: 6053: 6049: 6042: 6037: 6035: 6030: 6028: 6023: 6022: 6019: 6013: 6009: 6006: 6003: 6001: 5998: 5996: 5995:Prius Gearbox 5993: 5991: 5988: 5986: 5983: 5981: 5978: 5976: 5973: 5970: 5967: 5966: 5954: 5948: 5941: 5935: 5927: 5921: 5913: 5907: 5899: 5895: 5891: 5887: 5880: 5872: 5868: 5864: 5860: 5856: 5852: 5848: 5844: 5837: 5829: 5825: 5819: 5811: 5807: 5803: 5801:9780802016379 5797: 5793: 5788: 5787: 5778: 5772: 5768: 5763: 5759: 5755: 5749: 5745: 5741: 5734: 5723: 5716: 5714: 5698: 5694: 5690: 5686: 5682: 5678: 5674: 5670: 5663: 5656: 5642: 5638: 5632: 5624: 5622:0-34-056831-3 5618: 5614: 5613: 5605: 5597: 5595:0-74-870531-7 5591: 5587: 5583: 5576: 5568: 5564: 5563: 5556: 5549: 5543: 5541: 5533: 5527: 5525: 5523: 5518: 5506: 5503: 5500: 5497: 5495: 5492: 5489: 5486: 5484: 5481: 5479: 5476: 5474: 5471: 5468: 5465: 5463: 5460: 5458: 5455: 5452: 5449: 5447: 5444: 5442: 5439: 5436: 5433: 5430: 5427: 5425: 5422: 5421: 5407: 5400: 5395: 5391: 5384: 5379: 5375: 5370: 5363: 5358: 5357: 5348: 5345: 5340: 5336: 5333: 5324: 5314: 5311: 5303: 5300:February 2021 5293: 5289: 5285: 5279: 5278: 5274: 5269:This section 5267: 5263: 5258: 5257: 5249: 5245: 5241: 5237: 5233: 5229: 5221: 5216: 5207: 5205: 5194: 5192: 5187: 5183: 5178: 5176: 5170: 5166: 5164: 5160: 5156: 5155:meshed-planet 5148: 5145: 5140: 5113: 5110: 5107: 5095: 5091: 5088: 5079: 5071: 5070: 5054: 5050: 5043: 5040: 5037: 5025: 5021: 5012: 5004: 5003: 4984: 4980: 4976: 4964: 4960: 4951: 4943: 4942: 4941: 4938: 4919: 4914: 4904: 4900: 4897: 4894: 4865: 4861: 4852: 4848: 4845: 4836: 4829: 4826: 4823: 4813: 4812: 4811: 4804: 4800: 4791: 4788: 4783: 4766: 4758: 4754: 4750: 4745: 4741: 4732: 4729: 4724: 4719: 4715: 4707: 4706: 4705: 4688: 4685: 4682: 4679: 4671: 4667: 4663: 4658: 4654: 4646: 4642: 4638: 4633: 4629: 4618: 4617: 4616: 4613: 4611: 4606: 4597: 4588: 4586: 4564: 4557: 4553: 4547: 4543: 4537: 4534: 4531: 4524: 4520: 4514: 4510: 4495: 4490: 4487: 4482: 4479: 4476: 4469: 4465: 4459: 4455: 4440: 4437: 4434: 4426: 4422: 4418: 4413: 4409: 4401: 4397: 4393: 4383: 4382: 4381: 4380: 4379: 4356: 4349: 4345: 4339: 4335: 4329: 4326: 4323: 4316: 4312: 4306: 4302: 4287: 4284: 4281: 4278: 4275: 4268: 4264: 4258: 4254: 4239: 4236: 4233: 4225: 4221: 4217: 4210: 4206: 4202: 4197: 4193: 4182: 4181: 4180: 4179: 4178: 4155: 4148: 4144: 4138: 4134: 4128: 4125: 4118: 4114: 4108: 4104: 4089: 4086: 4083: 4076: 4072: 4066: 4062: 4052: 4051: 4050: 4049: 4048: 4041: 4024: 4016: 4012: 4008: 4003: 3999: 3991: 3987: 3983: 3978: 3974: 3967: 3964: 3957: 3956: 3955: 3951: 3934: 3927: 3923: 3917: 3913: 3907: 3904: 3897: 3893: 3887: 3883: 3877: 3874: 3867: 3866: 3865: 3863: 3858: 3849: 3832: 3829: 3824: 3820: 3814: 3810: 3806: 3801: 3797: 3791: 3787: 3783: 3778: 3774: 3768: 3764: 3756: 3755: 3754: 3737: 3733: 3710: 3706: 3683: 3679: 3649: 3645: 3641: 3636: 3632: 3625: 3621: 3613: 3609: 3605: 3602: 3597: 3593: 3585: 3567: 3563: 3557: 3553: 3545: 3541: 3537: 3532: 3528: 3520: 3502: 3498: 3491: 3487: 3483: 3478: 3474: 3465: 3461: 3457: 3454: 3449: 3445: 3437: 3419: 3415: 3408: 3404: 3400: 3395: 3391: 3382: 3378: 3374: 3371: 3366: 3362: 3354: 3335: 3331: 3327: 3322: 3318: 3311: 3307: 3299: 3295: 3291: 3288: 3283: 3279: 3271: 3253: 3249: 3243: 3239: 3231: 3227: 3223: 3218: 3214: 3206: 3205: 3204: 3174: 3155: 3125: 3116: 3097: 3067: 3058: 3050: 3049: 3028: 2996: 2987: 2956: 2938: 2929: 2921: 2920: 2899: 2867: 2858: 2827: 2809: 2800: 2792: 2791: 2790: 2779: 2774: 2770: 2756: 2741: 2729: 2725: 2716: 2702: 2697: 2695: 2679: 2667: 2663: 2654: 2650: 2641: 2619: 2604: 2600: 2591: 2579: 2572: 2568: 2555: 2543: 2534: 2531: 2527: 2522: 2518: 2508: 2495: 2480: 2468: 2464: 2455: 2446: 2434: 2422: 2413: 2410: 2399: 2375: 2363: 2354: 2319: 2307: 2292: 2267: 2255: 2246: 2237: 2236: 2235: 2179: 2167: 2133: 2122: 2120: 2116: 2062: 2049: 2037: 2028: 2001: 1972: 1960: 1958: 1954: 1924: 1912: 1903: 1900: 1893: 1892: 1891: 1874: 1871: 1862: 1854: 1851: 1848: 1842: 1839: 1830: 1822: 1819: 1816: 1810: 1801: 1796: 1789: 1788: 1787: 1773: 1763: 1758: 1755: 1746: 1742: 1733: 1722: 1720: 1716: 1700: 1697: 1688: 1667: 1655: 1651: 1642: 1609: 1605: 1596: 1583: 1579: 1570: 1562: 1551: 1539: 1531: 1524: 1523: 1522: 1499: 1484: 1480: 1471: 1459: 1453: 1444: 1429: 1425: 1416: 1404: 1398: 1389: 1381: 1380: 1359: 1346: 1334: 1326: 1317: 1304: 1292: 1288: 1279: 1271: 1262: 1254: 1253: 1232: 1220: 1208: 1200: 1191: 1178: 1166: 1162: 1153: 1145: 1136: 1128: 1127: 1106: 1092: 1088: 1079: 1072: 1063: 1052: 1048: 1039: 1028: 1020: 1019: 1018: 1013:respectively. 1012: 1008: 1004: 982: 978: 969: 965: 956: 947: 946:carrier frame 943: 939: 935: 931: 909: 905: 896: 892: 883: 879: 870: 862: 861: 860: 839: 836: 834: 823: 817: 807: 803: 794: 789: 785: 776: 765: 761: 752: 741: 733: 730: 728: 717: 711: 700: 696: 687: 682: 678: 669: 658: 654: 645: 634: 622: 621: 620: 560: 555: 548: 544: 540: 536: 533: 531: 527: 523: 520: 517: 513: 512:Carrier frame 510: 507: 504: 503: 502: 499: 489: 485: 471: 463: 443: 434: 432: 428: 406: 402: 393: 384: 367: 364: 353: 342: 338: 329: 318: 317: 316: 296: 281: 272: 267: 265: 262:invented the 261: 257: 253: 249: 247: 243: 239: 234: 232: 227: 223: 219: 218: 213: 212: 205: 203: 199: 195: 194: 189: 179: 172: 168: 164: 160: 158: 154: 150: 149:differentials 146: 141: 139: 135: 131: 127: 123: 119: 115: 111: 107: 103: 95: 86: 84: 80: 76: 71: 69: 65: 64:pitch circles 60: 56: 52: 48: 39: 33: 19: 6663:Racing slick 6600:Transfer box 6570:Park-by-wire 6565:Parking pawl 6514: 6480:Differential 6455:Direct-drive 6437:Transmission 6427:Steam engine 6372:Part of the 6371: 6180:Differential 6175:Transmission 6128:Spiral bevel 6076: 5952: 5947: 5939: 5934: 5920: 5906: 5889: 5885: 5879: 5846: 5842: 5836: 5827: 5818: 5785: 5777: 5739: 5733: 5700:. Retrieved 5675:(1): 27–43. 5672: 5668: 5655: 5644:. Retrieved 5640: 5631: 5611: 5604: 5585: 5575: 5561: 5555: 5547: 5531: 5451:Ford Model T 5408:transmission 5341: 5337: 5329: 5306: 5297: 5282:Please help 5270: 5246: 5242: 5238: 5234: 5230: 5226: 5200: 5182:World War II 5179: 5171: 5167: 5162: 5158: 5154: 5152: 4939: 4886: 4808: 4786: 4784: 4781: 4703: 4614: 4609: 4602: 4581: 4373: 4172: 4042: 4039: 3952: 3949: 3859: 3855: 3847: 3669: 3200: 2788: 2698: 2509: 2400: 2345: 2123: 2118: 1961: 1956: 1952: 1950: 1889: 1723: 1718: 1714: 1633: 1520: 1016: 1010: 1006: 1002: 945: 941: 937: 933: 858: 618: 558: 547:Annular gear 546: 543:Annulus gear 542: 538: 534: 529: 525: 521: 515: 511: 505: 495: 486: 464: 435: 430: 426: 385: 382: 287: 268: 250: 235: 215: 208: 206: 191: 185: 176: 170: 142: 137: 133: 129: 125: 121: 113: 105: 101: 100: 78: 75:annulus gear 74: 72: 50: 46: 44: 6641:Alloy wheel 6500:Drive wheel 6490:Drive shaft 6450:Chain drive 6306:Chain drive 6266:Wheel train 6138:Herringbone 5332:3D printing 5252:3D printing 2699:In bicycle 1011:planet gear 1009:, and each 522:Planet gear 278: 1650 231:epitrochoid 116:, gears or 83:gear ratios 6769:Categories 6726:Alternator 6374:Automobile 6363:Powertrain 6301:Belt drive 6286:Ball screw 6233:Derailleur 6067:Worm drive 5828:buseco.net 5810:1036858215 5771:1568986815 5762:1036836698 5646:2024-09-25 5513:References 5446:Epicycloid 5406:Ravigneaux 5210:Advantages 3862:gear train 498:gear ratio 202:precession 153:bevel gear 68:epicycloid 6595:Transaxle 6560:Manumatic 6530:Gearshift 6402:Fuel cell 6316:Freewheel 6296:Jackscrew 6291:Leadscrew 6168:Mechanics 5505:Uni Wheel 5271:does not 5111:− 5096:ω 5092:− 5080:ω 5041:− 5026:ω 5013:ω 4965:ω 4952:ω 4901:− 4866:ω 4862:− 4853:ω 4837:ω 4827:− 4787:ring gear 4755:ω 4742:ω 4716:ω 4683:− 4668:ω 4664:− 4655:ω 4643:ω 4639:− 4630:ω 4521:ω 4511:ω 4483:− 4466:ω 4456:ω 4423:ω 4419:− 4410:ω 4398:ω 4394:− 4313:ω 4303:ω 4282:− 4265:ω 4255:ω 4222:ω 4218:− 4207:ω 4203:− 4194:ω 4129:− 4115:ω 4105:ω 4073:ω 4063:ω 4013:ω 4009:− 4000:ω 3988:ω 3984:− 3975:ω 3908:− 3894:ω 3884:ω 3821:ω 3811:τ 3798:ω 3788:τ 3775:ω 3765:τ 3734:τ 3707:τ 3680:τ 3610:τ 3606:− 3594:τ 3542:τ 3529:τ 3462:τ 3458:− 3446:τ 3379:τ 3375:− 3363:τ 3296:τ 3292:− 3280:τ 3228:τ 3215:τ 3175:α 3117:α 3059:α 3029:α 2997:− 2988:α 2930:α 2900:α 2868:− 2859:α 2801:α 2701:hub gears 2355:− 2247:− 2115:clockwise 2029:− 1863:ω 1840:− 1831:ω 1802:ω 1689:ω 1656:ω 1652:≠ 1643:ω 1610:ω 1606:− 1597:ω 1584:ω 1580:− 1571:ω 1532:− 1500:ω 1445:ω 1390:ω 1360:ω 1327:− 1318:ω 1263:ω 1233:ω 1201:− 1192:ω 1137:ω 1107:ω 1064:ω 1040:ω 1003:ring gear 934:ring gear 910:ω 897:ω 884:ω 871:ω 824:ω 804:− 786:− 777:ω 762:− 753:ω 718:ω 679:− 670:ω 646:ω 539:Moon gear 535:Ring gear 530:ring gear 516:planetary 431:ring gear 271:Desargues 264:bookwheel 167:Bookwheel 126:sun wheel 6754:Category 6693:Tubeless 6678:Run-flat 6658:Off-road 6475:Coupling 6397:Electric 6279:See also 6258:Horology 6248:Sprocket 6238:Hub gear 6221:Bicycles 6214:Examples 6185:Coupling 6154:Involute 6008:Archived 5697:54663891 5467:Hub gear 5417:See also 2694:tractors 2096:⁠− 2077:⁠− 1634:only if 1007:sun gear 938:sun gear 928:are the 582:⁠− 563:⁠− 528:and the 526:sun gear 506:Sun gear 429:and the 427:sun gear 217:Almagest 214:(a.k.a. 193:Almagest 136:gear or 122:sun gear 89:Overview 6159:Cycloid 6133:Helical 6055:Systems 5871:4986932 5851:Bibcode 5722:Gearing 5677:Bibcode 5457:Gearbox 5351:Gallery 5292:removed 5277:sources 5180:During 3671:where: 2232:⁠ 2220:⁠ 2216:⁠ 2204:⁠ 2111:⁠ 2092:⁠ 932:of the 613:⁠ 601:⁠ 597:⁠ 578:⁠ 190:in the 182:History 157:coaxial 138:annulus 130:carrier 118:pinions 70:curve. 53:) is a 6744:Portal 6704:Hybrid 6668:Radial 6646:Hubcap 6460:Clutch 6407:Hybrid 6376:series 6228:Cogset 6205:Offset 6106:Shapes 5869:  5808:  5798:  5769:  5760:  5750:  5702:20 May 5695:  5619:  5592:  5223:angle. 4887:where 2754:  2677:  2493:  1957:output 1953:inputs 1890:where 1719:output 1665:  1005:, the 944:, and 859:where 383:where 173:, 1588 114:planet 6780:Gears 6688:Spare 6631:Wheel 6535:Giubo 6190:Train 6123:Crown 6118:Bevel 6048:Gears 5867:S2CID 5725:(PDF) 5693:S2CID 5665:(PDF) 5437:(CVT) 5186:radar 4378:=0, 4177:=0, 4047:=0, 2218:, or 2094:, or 1715:input 580:, or 545:, or 108:is a 59:gears 6683:Snow 6673:Rain 6653:Tire 6113:Spur 5806:OCLC 5796:ISBN 5767:ISBN 5758:OCLC 5748:ISBN 5704:2014 5617:ISBN 5590:ISBN 5275:any 5273:cite 1521:and 496:The 209:The 147:and 134:ring 110:gear 6636:Rim 5894:doi 5890:120 5859:doi 5685:doi 5286:by 4704:or 2213:64 2089:16 1693:... 575:16 220:), 124:or 104:or 45:An 6771:: 5888:. 5865:. 5857:. 5847:21 5845:. 5826:. 5804:. 5794:. 5792:69 5756:. 5746:. 5744:19 5712:^ 5691:. 5683:. 5673:32 5671:. 5667:. 5639:. 5584:. 5565:. 5539:^ 5521:^ 5193:. 4603:A 4587:. 4502:so 4447:or 4294:so 4246:or 4096:so 2229:4 2207:16 2108:2 2083:24 940:, 936:, 610:2 594:2 569:24 541:, 537:, 280:. 275:c. 233:. 159:. 6413:) 6409:( 6355:e 6348:t 6341:v 6040:e 6033:t 6026:v 5914:. 5900:. 5896:: 5873:. 5861:: 5853:: 5830:. 5812:. 5764:. 5706:. 5687:: 5679:: 5649:. 5625:. 5598:. 5313:) 5307:( 5302:) 5298:( 5294:. 5280:. 5117:) 5114:1 5108:R 5105:( 5100:c 5089:= 5084:s 5055:R 5051:/ 5047:) 5044:1 5038:R 5035:( 5030:c 5022:= 5017:r 4988:) 4985:R 4981:/ 4977:1 4974:( 4969:s 4961:= 4956:r 4924:s 4920:N 4915:/ 4909:r 4905:N 4898:= 4895:R 4870:s 4857:r 4849:R 4846:= 4841:c 4833:) 4830:1 4824:R 4821:( 4767:. 4764:) 4759:r 4751:+ 4746:s 4738:( 4733:2 4730:1 4725:= 4720:c 4689:, 4686:1 4680:= 4672:c 4659:r 4647:c 4634:s 4610:R 4565:. 4558:r 4554:N 4548:s 4544:N 4538:+ 4535:1 4532:= 4525:c 4515:r 4496:, 4491:R 4488:1 4480:1 4477:= 4470:c 4460:r 4441:, 4438:R 4435:= 4427:c 4414:r 4402:c 4376:s 4357:. 4350:s 4346:N 4340:r 4336:N 4330:+ 4327:1 4324:= 4317:c 4307:s 4288:, 4285:R 4279:1 4276:= 4269:c 4259:s 4240:, 4237:R 4234:= 4226:c 4211:c 4198:s 4175:r 4156:. 4149:s 4145:N 4139:r 4135:N 4126:= 4119:r 4109:s 4090:, 4087:R 4084:= 4077:r 4067:s 4045:c 4025:. 4017:c 4004:r 3992:c 3979:s 3968:= 3965:R 3935:. 3928:s 3924:N 3918:r 3914:N 3905:= 3898:r 3888:s 3878:= 3875:R 3833:0 3830:= 3825:s 3815:s 3807:+ 3802:c 3792:c 3784:+ 3779:r 3769:r 3738:c 3711:s 3684:r 3650:s 3646:N 3642:+ 3637:r 3633:N 3626:s 3622:N 3614:c 3603:= 3598:s 3568:r 3564:N 3558:s 3554:N 3546:r 3538:= 3533:s 3503:s 3499:N 3492:s 3488:N 3484:+ 3479:r 3475:N 3466:s 3455:= 3450:c 3420:r 3416:N 3409:s 3405:N 3401:+ 3396:r 3392:N 3383:r 3372:= 3367:c 3336:s 3332:N 3328:+ 3323:r 3319:N 3312:r 3308:N 3300:c 3289:= 3284:r 3254:s 3250:N 3244:r 3240:N 3232:s 3224:= 3219:r 3179:r 3166:r 3161:N 3156:+ 3151:s 3146:N 3138:r 3133:N 3126:+ 3121:s 3108:r 3103:N 3098:+ 3093:s 3088:N 3080:s 3075:N 3068:= 3063:c 3033:s 3021:r 3016:N 3009:s 3004:N 2992:c 2980:r 2975:N 2967:r 2962:N 2957:+ 2952:s 2947:N 2939:= 2934:r 2904:r 2892:s 2887:N 2880:r 2875:N 2863:c 2851:s 2846:N 2838:r 2833:N 2828:+ 2823:s 2818:N 2810:= 2805:s 2757:. 2746:r 2742:N 2734:r 2730:N 2726:+ 2721:s 2717:N 2680:. 2672:r 2668:N 2664:+ 2659:s 2655:N 2651:: 2646:s 2642:N 2620:, 2609:r 2605:N 2601:+ 2596:s 2592:N 2584:s 2580:N 2573:= 2569:) 2560:s 2556:N 2548:r 2544:N 2535:+ 2532:1 2528:( 2523:/ 2519:1 2496:. 2485:s 2481:N 2473:r 2469:N 2465:+ 2460:s 2456:N 2447:= 2439:s 2435:N 2427:r 2423:N 2414:+ 2411:1 2380:r 2376:N 2368:s 2364:N 2324:r 2320:N 2312:p 2308:N 2272:p 2268:N 2260:s 2256:N 2226:/ 2223:1 2210:/ 2184:r 2180:N 2172:p 2168:N 2138:r 2134:N 2105:/ 2102:3 2098:+ 2086:/ 2079:+ 2063:. 2054:p 2050:N 2042:s 2038:N 2006:p 2002:N 1977:s 1973:N 1929:p 1925:N 1917:s 1913:N 1904:= 1901:n 1875:0 1872:= 1867:c 1858:) 1855:n 1852:+ 1849:1 1846:( 1843:2 1835:r 1826:) 1823:n 1820:+ 1817:2 1814:( 1811:+ 1806:s 1797:n 1774:, 1768:p 1764:N 1759:2 1756:+ 1751:s 1747:N 1743:= 1738:r 1734:N 1701:0 1698:= 1668:. 1660:c 1647:r 1614:c 1601:r 1588:c 1575:s 1563:= 1556:s 1552:N 1544:r 1540:N 1504:r 1489:r 1485:N 1481:+ 1476:s 1472:N 1464:r 1460:N 1454:+ 1449:s 1434:r 1430:N 1426:+ 1421:s 1417:N 1409:s 1405:N 1399:= 1394:c 1364:s 1351:r 1347:N 1339:s 1335:N 1322:c 1309:r 1305:N 1297:r 1293:N 1289:+ 1284:s 1280:N 1272:= 1267:r 1237:r 1225:s 1221:N 1213:r 1209:N 1196:c 1183:s 1179:N 1171:r 1167:N 1163:+ 1158:s 1154:N 1146:= 1141:s 1111:c 1102:) 1097:r 1093:N 1089:+ 1084:s 1080:N 1076:( 1073:= 1068:r 1057:r 1053:N 1049:+ 1044:s 1033:s 1029:N 987:p 983:N 979:, 974:s 970:N 966:, 961:r 957:N 914:c 906:, 901:p 893:, 888:s 880:, 875:r 840:0 837:= 828:c 818:) 812:p 808:N 799:r 795:N 790:( 781:p 770:p 766:N 757:r 746:r 742:N 734:0 731:= 722:c 712:) 705:p 701:N 697:+ 692:s 688:N 683:( 674:p 663:p 659:N 655:+ 650:s 639:s 635:N 607:/ 604:3 591:/ 588:3 584:+ 572:/ 565:+ 472:A 448:p 444:n 411:r 407:N 403:, 398:s 394:N 368:A 365:= 358:p 354:n 347:r 343:N 339:+ 334:s 330:N 301:p 297:n 34:. 20:)

Index

Planetary gearbox
Starter ring gear

gear reduction
gears
pitch circles
epicycloid
gear ratios

gear
pinions
pencil sharpeners
differentials
bevel gear
coaxial

Bookwheel
Claudius Ptolemy
Almagest
Antikythera Mechanism
precession
Mathematical Syntaxis
Almagest
Claudius Ptolemy
deferent and epicycles
epitrochoid
Antikythera Mechanism
ellipticity of its orbit
apsidal precession
Richard of Wallingford

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