
	Where results make sense

Topic: Epicyclic gearing

Related Topics

Gear

Gear ratio

Derailleur gears

Gearbox

Torque converter

Automatic transmission

Bicycle

CVT

Power (physics)

Aminotic fluid

Mechanical advantage

Strategic management

Mechanical work

Snowmobile

Machine

In the News (Wed 2 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Epicyclic gearing - TheBestLinks.com - Gear, Clockwise and counterclockwise, Hub gear, Automatic transmission, ... (Site not responding. Last check: 2007-10-14)
		Epicyclic gearing or planetary gearing is a gear system that consists of one or more outer gears, or planet gears, rotating about a central, or sun gear.
		The gear ratios between the input rotation and output rotation in the epicyclic gear train depends on what components are used to transfer rotation into and out of the system.
		The gear ratio in 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.
	www.thebestlinks.com /Epicyclic_gearing.html (693 words)

	Epicyclic gearing - Wikipedia, the free encyclopedia
		Epicyclic gearing or planetary gearing is a gear system that consists of one or more outer gears, or planet gears, rotating about a central, or sun gear.
		The gear ratio in 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.
		In any epicyclic gearing system, one of these three basic components is held stationary; one of the two remaining components is an input, providing power to the system, while the last component is an output, receiving power from the system.
	en.wikipedia.org /wiki/Epicyclic_gearing (956 words)

	Hub gear - Wikipedia, the free encyclopedia
		Hub gears work by internal planetary or epicyclic gearing, which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed relative to the rear wheel's sprocket depending on which gear is selected.
		Unlike derailleur gears, where the gears and mechanism are exposed to the elements, hub gears are enclosed within the hub of the bicycle's rear wheel.
		Gears are changed by a cable which is tightened or loosened by a lever or twist grip on the handlebars.
	en.wikipedia.org /wiki/Hub_gear (679 words)

	Hub gear - Wikipedia, the free encyclopedia (Site not responding. Last check: 2007-10-14)
		Gears are changed by a cable which is tightened or loosened by a lever on the handlebars.
		Hub gears work by internal planetary or epicyclic gearing, which means that the outer case of the hub gear unit (which is attached to the spokes) is made to turn at a different speed to the rear wheel's axle depending on which gear is selected.
		Hub gears were invented in 1903 by an English company called Sturmey Archer, and by the 1930s they had become common on bikes across the world.
	www.encyclopedia-online.info /Hub_gear (540 words)

	Articles - Gear (Site not responding. Last check: 2007-10-14)
		Different-sized gears are often used in pairs for a mechanical advantage, allowing the torque of the driving gear to produce a larger torque in the driven gear at lower speed, or a smaller torque at higher speed.
		A disadvantage of helical gears is a resultant thrust along the axis of the gear, which needs to be accommodated by appropriate thrust bearings, and a greater degree of sliding friction between the meshing teeth, often addressed with specific additives in the lubricant.
		A ´´crown gear´´ or ´´contrate gear´´ is a special form of bevel gear which has teeth at right angles to the plane of the wheel; it meshes with a straight cut spur gear or pinion on a right-angled axis to its own, or with an escapement such as found in mechanical clocks.
	www.seekj.com /articles/Gear (854 words)

	Motion Control Technology
		The ring gear is stationary, and the input sun gear pinion drives the planet gears, which then walk in the same rotational direction as the sun gear.
		Helical gearing is similar to spur gearing except the teeth of the gears are not straight or parallel to the axis of rotation.
		For this reason all planet gears have to be captivated on both sides of the gear and both the input pinion and output carrier plate/shaft have to be supported with bearings to handle the axial loading.
	www.techbriefs.com /motion/features/feat_1204.html (1542 words)

	Epicyclic gearing: Facts and details from Encyclopedia Topic (Site not responding. Last check: 2007-10-14)
		Epicyclic gearing systems may also incorporate the use of an outer ring gear or annulus, EHandler: no quick summary.
		The gear ratio[For more facts and a topic of this subject, click this link] in an epicyclic gearing system is somewhat non-intuitive, EHandler: no quick summary.
		In mechanical or automotive engineering a freewheel is a device in a transmission that disengages the drive shaft from the driven shaft in the case that the driven...
	www.absoluteastronomy.com /encyclopedia/e/ep/epicyclic_gearing.htm (1132 words)

	Epicycloidal gears and gear tooth arrangement therefor - Patent 4446752
		The gear train is provided with a novel input means in the form of an offset eccentric crank, which also combines the functions of input and output bearings, and a counterweight for offsetting the eccentric motion.
		The gear train is provided as a modular system, in which a number of different "halves" of the gear train are provided, these "halves" being selectively matchable with one another in order to provide a wide variety and range of gear ratios from a limited number of component halves.
		The gears of the instant invention are provided with a novel tooth design, which uses a quite high pressure angle of 30 degrees, plus or minus 7 degrees, depending upon the difference in the numbers of teeth provided on the meshing gears.
	www.freepatentsonline.com /4446752.html (4224 words)

	Epicyclic gearing
		If the gear 'A' is fixed and 'B' allowed to rotate freely around it constrained within an annulus; then for one rotation of 'A' and corresponding rotation of 'B' the point of contact on the annulus would have moved through a distance equal to 2x P x Ra.
		In normal operation epicyclic gear designs the planet pins are straddle mounted on a rigid carrier and are precisely aligned to each other.
		Other designs include the Allen-Stoeckicht where the split annulus of a double epicyclic gear are given a degree of movement within the carrier fo the two rings, this carrier itself is given a degree of axial movement by being fixed to the outer casing by a straight cut tooth coupling.
	www.marineengineering.org.uk /gearing/grepiMain.htm (773 words)

	Actuator for steering rear wheels - Patent 5595089
		In another preferred embodiment of the invention, when the support member (3) is molded, a ring gear (12) of the epicyclic gearing (7) may be formed around the part of the inner peripheral wall of the support member in accordance with the configuration of the mold used.
		The ring gear 12 is used in common between the pair of planetary gear trains, and is simultaneously molded as the resin member 3 is molded integrally with the casing 1.
		Subsequently, the nut 41 is mounted on the actuator shaft 6, the shafts 35, 36, 37 and 38 are mounted on the nut 41, and the planet gears 31, 32, 33 and 34 are mounted on the shafts 35, 36, 37 and 38, respectively.
	www.freepatentsonline.com /5595089.html (4252 words)

	Evolution of Early British Derailleurs
		Consequently an epicyclic gear in the hub could be substantially smaller and lighter than a similar gear in the chainwheel or bracket.
		The patent outlined how, if the rider selects lower gear, "the segments of the wheel are forced outwards moving on their rounded ends which serve as hinges, and away from the driving chain so that the latter is then driven by the smaller driving [i.e.
		The idea of the rider being able to change gear whilst riding was still sufficiently novel for the patent to state that "sometimes" the mechanism was "so arranged that the change of gear can be made whilst riding..." This was done by "the movement of a lever and a slider thereon".
	www.users.globalnet.co.uk /~hadland/old_derail.htm (10494 words)

	Definition of Gears
		Different-sized gears are often used in pairs, allowing the torque of the driving gear to produce a larger torque in the driven gear at lower speed, or a smaller torque at higher speed.
		A disadvantage of helical gears is a resultant thrust along the axis of the gear, which needs to be accomodated by appropriate thrust bearings.
		A variation of this mechanism is used in the differential gear, a complex arrangement of gears that transmits power to two axles moving at variable speeds, such as those on a cornering automobile.
	www.wordiq.com /definition/Gears (700 words)

	Split Torque Epicyclic Helicopter Gearing
		The first planetary gear is in meshing engagement with the stationary sun gear and the second planetary gear is in meshing engagement with the rotor sun gear.
		The first planetary gear is also in meshing engagement with the internal teeth of a first ring gear and the second planetary gear is also in meshing engagement with the internal teeth of a second ring gear.
		The first planetary gear has a first planetary pitch diameter, and the second planetary gear has a second planetary pitch diameter, wherein the first planetary pitch diameter is different from the second planetary pitch diameter.
	www.delocorp.net /page5.html (472 words)

	Helical Gears (Site not responding. Last check: 2007-10-14)
		Helical Gears are similar to spur gears but the teeth lie at an angle to the axis.
		Allen-Stoeckicht where the split annulus of a double epicyclic gear are given a degree of movement within the carrier...
		This patent describes a speed change pulley drive mechanism employing an epicyclic gear train with a ring gear, multiple planet gears and a sun gear, input and output members, and a clutch operable to either directly connect the input and output...
	www.nissei-usa.com /Helical-Gears/epicyclic.html (819 words)

	Epicyclic Maintaining Work (power) - Topic Powered by eve community (Site not responding. Last check: 2007-10-14)
		Moore has incorporated an unusual winding arrangement using a couple of pinions (with epicyclic tooth forms) and a ratchet wheel that has the ratchet teeth on the outside and epicyclic teeth (pointing inward) on the inside.
		The epicyclic gear form is theoretically the least friction inducing.
		I believe this type of maintaining power uses a planetary gear arrangement for applying a forward power to the train, while the winding torque is in the opposite direction.
	nawcc-mb.infopop.cc /groupee/forums/a/tpc/f/4166015461/m/9056053622 (651 words)

	Bicycle (Site not responding. Last check: 2007-10-14)
		Internal hub gearing works by planetary, or epicyclic, gearing, in which the outer case of the hub gear unit turns at a different speed relative to the rear axle depending on which gear is selected.
		External gearing utilizes derailleurs, which can be placed on both the front chainring and on the rear cluster or cassette, to push the chain to either side, derailing it from the sprockets.
		By gearing this wheel to the regular front wheel so that it spun in the opposite direction at equal speed, the net angular momentum of both wheels together was close to zero.
	bicycle.ask.dyndns.dk (6235 words)

	Epicyclic gearing: Facts and details from Encyclopedia Topic (Site not responding. Last check: 2007-10-14)
		Epicyclic gearing or planetary gearing is a gear A toothed wheel that engages another toothed mechanism in order to change the speed or direction of transmitted motion
		The gear ratio[Follow this hyperlink for a summary of this subject] in 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.
		gearing was developed for portable RADAR Measuring instrument in which the echo of a pulse of microwave radiation is used to detect and locate distant objects
	www.absoluteastronomy.com /e/epicyclic_gearing (954 words)

	Facetation / george goodall
		As noted, Ramelli’s epicyclic gearing appears similar to those in Leonardo’s manuscripts.
		However, epicyclic gearing was not unknown to the engineers of antiquity and Ramelli’s contemporary horologists (as described by the other body of work of that LIS hero Derek J. de Solla Price).
		Ramelli is born in the town of Lake Lugano, on the border between Switzerland and the Duchy of Milan.
	www.deregulo.com /facetation/2005_03_20_archives.html (4309 words)

	Computer Hubs (Site not responding. Last check: 2007-10-14)
		As I understand it, there are several different ways of driving the gearing system, involving various configurations of fixed parts and movable parts.
		Some that I looked at had a fixed sun gear, and movable planetary gear holder that provided the input rotation; I don't know which is more common.
		A distinction between epicyclic gearing in general and cycling hubs in particular would be good to have.
	www.wwwtln.com /finance/49/computer-hubs.html (1266 words)

	The Slide Rules - Ing. Giovanni Pastore
		The design of the Antikythera Calculator epicyclic gearing, found in a shipwreck of the I century B.C., makes to presume that some Hellenistic scientists should know the calculation of the planetary movement of celestial bodies and could have obtained the same results reached in the modern age.
		The scientific value of this gearing mechanism is undeniable, because, it anticipates and uses the heliocentric theory proposed by Copernico in 1543 and advances the cinematic study of the epicyclic gearings published by Robert Willis in 1841.
		This instrument was discovered in the Aegean sea near the isle of Antikythera at the beginning of XX century.
	www.giovannipastore.it /index_english.htm (1720 words)

	The Ultimate Overdrive (mechanics) - American History Information Guide and Reference
		An overdrive is a device which was commonly used on rear-wheel drive automobiles to allow the choice of an extra-high overall gear ratio for high speed cruising, thus saving fuel.
		Automotive transmissions manufactured since the 1980s tend to include a larger selection of gear ratios than before, the highest of which is usually greater than 1:1.
		The overdrive consists of a hydraulically operated epicyclic gear train bolted behind the transmission unit.
	www.historymania.com /american_history/Overdrive_(Transmission) (205 words)

	Designing rectangular gears
		Gears have been made in the past with several profile systems, the two
		Epicyclic gearing is used only in the manufacture of
		The gears in question do indeed have teeth that form a rounded corner.
	www.groupsrv.com /science/about5811.html (1411 words)

	Planetary Gear Motor
		A large family gear arrangements are under the general name of Epicyclic gearing.
		The name planetary is used interchangeably with epicyclic to denote the whole family of gears.
		The reversibility allows this power to be transmitted to the high speed end of the gear box without causing any damage to the gears, couplings or other elements in the line of power transmission.
	www.lariissa.com /pgm.htm (314 words)

	Ultramatic - (Site not responding. Last check: 2007-10-14)
		The Ultramatic was a hydraulic torque converter automatic transmission with a two-speed plus reverse epicyclic geartrain and torque converter lockup, called Direct Drive by Packard.
		The intention was that in normal driving, the high (1:1) ratio would be selected at all times, and the two stage, dual turbine torque converter (actually a total of four turbines were employed) used to reduce gearing for starting off.
		At a speed between 15 and 56 mph (depending on rear axle ratio which affected the rate of governor pressure rise), governor pressure eventually overcame the opposing throttle pressure, as determined by carburetor linkage position, causing the Direct Shift Valve to apply the direct drive clutch.
	psychcentral.com /psypsych/wiki/Ultramatic (1715 words)

	the Otherpower.com Discussion Board \|\| a gearing question
		The outside teeth of the annulus will be the output and will turn a simple spur gear that is connected to a sun gear in another epicyclic gearing system or a generator.
		Since they are mounted on the planetary gear carrier, that requires the planetary gear carrier be NOT stationary.
		The non cog gear selection probably is the reason why it is not referred to as a gearbox....
	www.fieldlines.com /story/2006/4/21/194212/962 (2412 words)

	Articles - Epicyclic gearing (Site not responding. Last check: 2007-10-14)
		If you want to derive this, just imagine the arm is locked, and calculate the gear ratio w_out/w_in=N_in/N_out.
		From the arms reference frame the ratio is always N_in/N_out, but from your frame all the speeds are increased by the angular velocity of the arm.
		Also, make sure N_sun+2*N_planet=N_ring where N is the number of teeth.
	www.x-moto.net /articles/Epicyclic_gearing (852 words)

	N04-012 - Sensitive Bearing Diagnostics for Rotorcraft Transmissions (Site not responding. Last check: 2007-10-14)
		Achieving true condition-based maintenance of advanced rotorcraft transmissions will require sensitive monitoring of bearing dynamics to characterize the gradual degradation of their condition.
		This is particularly difficult for the planetary gear bearings of epicyclic gearing, which can only be "heard" through a gear mesh with potent dynamics of its own.
		In the Phase I effort, we will analyze existing seeded-fault data to demonstrate the feasibility of applying the Dynamical Instruments technique to achieve sensitive monitoring of bearing condition in epicyclic gearing.
	www.navysbir.com /04_1/168.htm (209 words)

	Rohloff Hub and mountain schlumpf sp? gearing - 'BentRider Online Forums (Site not responding. Last check: 2007-10-14)
		My understanding is that Rohloff do not approve of the use of their hub in conjunction with a mountain drive.
		I haven't heard this, but the specs for Rohloff does specify a minimum gear ratio of chainring/cog=2.4 (link), presumably because pedaling hard with a smaller gear ratio puts too much torque on the hub.
		Nobody does this, obviously - most people use lower gears and count on the fact that the pedal force of an average recumbent rider spinning up a hill is much smaller than that of a strong upright rider standing on the pedals.
	www.bentrideronline.com /messageboard/showthread.php?mode=hybrid&t=9260 (533 words)

	Power-Handle a winch handle with a built-in gearing from Aronowitsch & Lyth AB - Best in test
		The epicyclic gearing and the drive shaft are manufactured in precision-machined aluminiumbronze; the spindles in stainless cold drawn acid-proof steel and the outer casing in investment casted surface treated aluminum!
		The epicyclic gearing in POWER-HANDLE gives a gear ratio of 3:1 in both directions.
		On self-tailing winches it is often possible for the operator to use his free hand to hold the torque reaction arm which in that case does not have to be placed over the line.
	www.arolyth.se /txpheng.html (469 words)

Try your search on: Qwika (all wikis)