Movatterモバイル変換

Jump to content

Gear train

From Wikipedia, the free encyclopedia

(Redirected fromGear ratio)

Mechanical transmission using multiple gears

Transmission of motion and force by gear wheels, compound train.^[1]

Illustration byGeorgius Agricola (1580) showing a toothed wheel that engages a slotted cylinder to form a gear train that transmits power from a human-powered treadmill to mining pump.

Agear train orgear set is amachine element of amechanical system formed by mounting two or moregears on a frame such that the teeth of the gears engage.

Gear teeth are designed to ensure thepitch circles of engaging gears roll on each other without slipping, providing a smooth transmission of rotation from one gear to the next.^[2] Features of gears and gear trains include:

Thegear ratio of the pitch circles of mating gears defines the speed ratio and themechanical advantage of the gear set.
Aplanetary gear train provides high gear reduction in a compact package.
It is possible to design gear teeth for gears that arenon-circular, yet still transmit torque smoothly.
The speed ratios ofchain andbelt drives are computed in the same way as gear ratios. Seebicycle gearing.

The transmission of rotation between contacting toothed wheels can be traced back to theAntikythera mechanism of Greece and thesouth-pointing chariot of China. Illustrations by the Renaissance scientistGeorgius Agricola show gear trains with cylindrical teeth. The implementation of theinvolute tooth yielded a standard gear design that provides a constant speed ratio.

Gear ratio

Two meshedspur gears showingtangent contact between theirpitch circles, each illustrated with broken blue lines; the gear on the left has 10 teeth and the gear on the right has 15 teeth.

Dimensions and terms

Thepitch circle of a given gear is determined by thetangent point contact between two meshing gears; for example, twospur gears mesh together when their pitch circles are tangent, as illustrated.^[3]^: 529

Thepitch diameterd is the diameter of a gear's pitch circle, measured through that gear's rotational centerline, and thepitch radiusr is the radius of the pitch circle.^[3]^: 529 The distance between the rotational centerlines of two meshing gears is equal to the sum of their respective pitch radii.^[3]^: 533

Thecircular pitchp is the distance, measured along the pitch circle, between one tooth and the corresponding point on an adjacent tooth.^[3]^: 529

The number of teethN per gear is an integer determined by the pitch circle and circular pitch.

Relationships

Spur gear tooth dimensions and how they are measured:
t = tooth thickness, along the pitch circle
p = circular pitch, along the pitch circle
a = addendum, radially
b = dedendum, radially
In this example, the gear has 20 teeth.

The circular pitchp of a gear can be defined as the circumference of the pitch circle using its pitch radiusr divided by the number of teethN:^[3]^: 530

p\equiv {\frac {2\pi r}{N}}

The thicknesst of each tooth, measured through the pitch circle, is equal to the gap between neighboring teeth (also measured through the pitch circle) to ensure the teeth on adjacent gears, cut to the same tooth profile, can mesh without interference. This means the circular pitchp is equal to twice the thickness of a tooth,^[3]^: 535

p=2t

In the United States, thediametral pitchP is the number of teeth on a gear divided by the pitch diameter; for SI countries, themodulem is the reciprocal of this value.^[3]^: 529 For any gear, the relationship between the number of teeth, diametral pitch or module, and pitch diameter is given by:

d={\frac {N}{P}}=N\cdot m

Since the pitch diameter is related to circular pitch as

d\equiv 2r={\frac {Np}{\pi }}

this means

{\frac {N}{P}}=N\cdot m={\frac {Np}{\pi }}

Rearranging, we obtain a relationship between diametral pitch and circular pitch:^[3]^: 530

P={\frac {1}{m}}={\frac {\pi }{p}}

Gear or speed ratio

Two meshing gears transmit rotational motion; note difference in rotational speeds is equal to the reciprocal of the ratio between the number of teeth on the two gears

For a pair of meshing gears, theangular speed ratio, also known as thegear ratio, can be computed from the ratio of the pitch radii or the ratio of the number of teeth on each gear. Define the angular speed ratioR_AB of two meshed gearsA andB as the ratio of the magnitude of their respective angular velocities:

R_{AB}\equiv {\frac {|\omega _{A}|}{|\omega _{B}|}}

Here, subscripts are used to designate the gear, so gearA has a radius ofr_A andangular velocity ofω_A withN_A teeth, which meshes with gearB which has corresponding values for radiusr_B, angular velocityω_B, andN_B teeth.

When these two gears are meshed and turn without slipping, the velocityv of the tangent point where the two pitch circles come in contact is the same on both gears, and is given by:^[3]^: 533

v=|r_{A}\omega _{A}|=|r_{B}\omega _{B}|

Rearranging, the ratio of angular velocity magnitudes is the inverse of the ratio of pitch circle radii:

{\frac {|\omega _{A}|}{|\omega _{B}|}}={\frac {r_{B}}{r_{A}}}

Therefore, the angular speed ratio can be determined from the respective pitch radii:^[3]^{: 533, 552}

R_{AB}\equiv \left|{\frac {\omega _{A}}{\omega _{B}}}\right|={\frac {r_{B}}{r_{A}}}

For example, if gearA has a pitch circle radius of 1 in (25 mm) and gearB has a pitch circle radius of 2 in (51 mm), the angular speed ratioR_AB is 2, which is sometimes written as 2:1. GearA turns at twice the speed of gearB. For every complete revolution of gearA (360°), gearB makes half a revolution (180°).

In addition, consider that in order to mesh smoothly and turn without slipping, these two gearsA andB must have compatible teeth. Given the same tooth and gap widths, they also must have the same circular pitchp, which means

p_{A}=p_{B}

or, equivalently

{\frac {2\pi r_{A}}{N_{A}}}={\frac {2\pi r_{B}}{N_{B}}}

This equation can be rearranged to show the ratio of the pitch circle radii of two meshing gears is equal to the ratio of their number of teeth:

{\frac {r_{B}}{r_{A}}}={\frac {N_{B}}{N_{A}}}

Since the angular speed ratioR_AB depends on the ratio of pitch circle radii, it is equivalently determined by the ratio of the number of teeth:

R_{AB}\equiv {\frac {|\omega _{A}|}{|\omega _{B}|}}={\frac {r_{B}}{r_{A}}}={\frac {N_{B}}{N_{A}}}

In other words, the [angular] speed ratio isinversely proportional to the radius of the pitch circle and the number of teeth of gearA, and directly proportional to the same values for gearB.

Torque ratio analysis using virtual work

The gear ratio also determines the transmitted torque. Thetorque ratioTR_AB of the gear train is defined as the ratio of its output torque to its input torque. Using the principle ofvirtual work, the gear train'storque ratio is equal to the gear ratio, or speed ratio, of the gear train. Again, assume we have two gearsA andB, with subscripts designating each gear and gearA serving as the input gear.

{\mathrm {TR} }_{AB}\equiv {\frac {T_{B}}{T_{A}}}

For this analysis, consider a gear train that has one degree of freedom, which means the angular rotation of all the gears in the gear train are defined by the angle of the input gear. The input torqueT_A acting on the input gearA is transformed by the gear train into the output torqueT_B exerted by the output gearB.

LetR_AB be the speed ratio, then by definition

R_{AB}\equiv {\frac {|\omega _{A}|}{|\omega _{B}|}}

Assuming the gears are rigid and there are no losses in the engagement of the gear teeth, then the principle ofvirtual work can be used to analyze the static equilibrium of the gear train. Because there is a single degree of freedom, the angleθ of the input gear completely determines the angle of the output gear and serves as the generalized coordinate of the gear train.

{\frac {d\theta }{dt}}=\omega _{A}

The speed ratioR_AB of the gear train can be rearranged to give the magnitude of angular velocity of the output gear in terms of the input gear velocity.

|\omega _{B}|={\frac {|\omega _{A}|}{R_{AB}}}

Rewriting in terms of a common angular velocity,

\omega _{A}=\omega ,\quad \omega _{B}={\frac {\omega }{R_{AB}}}\!

The principle of virtual work states the input force on gearA and the output force on gearB using applied torques will sum to zero:^[4]

F_{\theta }=T_{A}{\frac {\partial \omega _{A}}{\partial \omega }}-T_{B}{\frac {\partial \omega _{B}}{\partial \omega }}=T_{A}-{\frac {T_{B}}{R_{AB}}}=0.

This can be rearranged to:

R_{AB}={\frac {T_{B}}{T_{A}}}

SinceR_AB is the gear ratio of the gear train, the input torqueT_A applied to the input gearA and the output torqueT_B on the output gearB are related by the same gear or speed ratio.

Mechanical advantage

The torque ratio of a gear train is also known as itsmechanical advantage; as demonstrated, the gear ratio and speed ratio of a gear train also give its mechanical advantage.

\mathrm {MA} \equiv {\frac {T_{B}}{T_{A}}}=R_{AB}

The mechanical advantageMA of a pair of meshing gears for which the input gearA hasN_A teeth and the output gearB hasN_B teeth is given by^[5]^: 74–76

\mathrm {MA} =R_{AB}=\left|{\frac {\omega _{A}}{\omega _{B}}}\right|={\frac {N_{B}}{N_{A}}}

This shows that if the output gearB has more teeth than the input gearA, then the gear trainamplifies the input torque. In this case, the gear train is called aspeed reducer and since the output gear must have more teeth than the input gear, the speed reducer amplifies the input torque.^[5]^: 76 When the input gear rotates faster than the output gear, then the gear train amplifies the input torque. Conversely, if the output gear has fewer teeth than the input gear, then the gear trainreduces the input torque;^[5]^: 68 in other words, when the input gear rotates slower than the output gear, the gear train reduces the input torque.

Hunting and non-hunting gear sets

Ahunting gear set is a set of gears where the gear teeth counts are relativelyprime on each gear in an interfacing pair. Since the number of teeth on each gear have no commonfactors, then any tooth on one of the gears will come into contact with every tooth on the other gear before encountering the same tooth again. This results in less wear and longer life of the mechanical parts.Anon-hunting gear set is one where the teeth counts are insufficiently prime. In this case, some particular gear teeth will come into contact with particular opposing gear teeth more times than others, resulting in more wear on some teeth than others.^[6]

Implementations

Gear trains with two gears

Two meshed spur gears, with a 2:1 ratio

The simplest example of a gear train has two gears. Theinput gear (also known as thedrive gear ordriver) transmits power to theoutput gear (also known as thedriven gear). The input gear will typically be connected to a power source, such as a motor or engine. In such an example, the output of torque and rotational speed from the output (driven) gear depend on the ratio of the dimensions of the two gears or the ratio of the tooth counts.

Idler gears

Gear train with anidler gear in the middle which does not affect the overall gear ratio but reverses the direction of rotation of the gear on the right.

In a sequence of gears chained together, the ratio depends only on the number of teeth on the first and last gear. The intermediate gears, regardless of their size, do not alter the overall gear ratio of the chain. However, the addition of each intermediate gear reverses the direction of rotation of the final gear.

An intermediate gear which does not drive a shaft to perform any work is called anidler gear. Sometimes, a single idler gear is used to reverse the direction, in which case it may be referred to as areverse idler. For instance, the typical automobilemanual transmission engages reverse gear by means of inserting a reverse idler between two gears.

Idler gears can also transmit rotation among distant shafts in situations where it would be impractical to simply make the distant gears larger to bring them together. Not only do larger gears occupy more space, the mass and rotational inertia (moment of inertia) of a gear is proportional to thesquare of its radius. Instead of idler gears, a toothed belt or chain can be used to transmittorque over distance.

Formula

If a simple gear train has three gears, such that the input gearA meshes with an intermediate gearI which in turn meshes with the output gearB, then the pitch circle of the intermediate gear rolls without slipping on both the pitch circles of the input and output gears. This yields the two relations

{\frac {|\omega _{A}|}{|\omega _{I}|}}={\frac {N_{I}}{N_{A}}},\quad {\frac {|\omega _{I}|}{|\omega _{B}|}}={\frac {N_{B}}{N_{I}}}.

The speed ratio of the overall gear train is obtained by multiplying these two equations for each pair (A-I andI-B) to obtain

R={\frac {|\omega _{A}|}{|\omega _{B}|}}={\frac {N_{B}}{N_{A}}}.

This is because the number of idler gear teethN_I cancels out when the gear ratios of the two subsets are multiplied:

{\begin{aligned}R_{final}&=R_{AI}\cdot R_{IB}\\&=\left({\frac {N_{I}}{N_{A}}}\right)\cdot \left({\frac {N_{B}}{N_{I}}}\right)=\left({\frac {N_{B}}{N_{A}}}\right)\end{aligned}}

Notice that this gear ratio is exactly the same as for the case when the gearsA andB engage directly. The intermediate gear provides spacing but does not affect the gear ratio. For this reason it is called anidler gear. The same gear ratio is obtained for a sequence of idler gears and hence an idler gear is used to provide the same direction to rotate the driver and driven gear. If the driver gear moves in the clockwise direction, then the driven gear also moves in the clockwise direction with the help of the idler gear.

Example

2 gears and anidler gear on a piece of farm equipment, with a ratio of 42:13 = 3.23:1

In the photo, assume the smallest gear (gearA, in the lower right corner) is connected to the motor, which makes it the drive gear or input gear. The somewhat larger gear in the middle (gearI) is called anidler gear. It is not connected directly to either the motor or the output shaft and only transmits power between the input and output gears. There is a third gear (gearB) partially shown in the upper-right corner of the photo. Assuming that gear is connected to the machine's output shaft, it is the output or driven gear.

Considering only gearsA andI, the gear ratio between the idler and the input gear can be calculated as if the idler gear was the output gear. The input gearA in this two-gear subset has 13 teeth (N_A) and the idler gearI has 21 teeth (N_I). Therefore, the gear ratio for this subsetR_AI is

R_{AI}={\frac {N_{I}}{N_{A}}}={\frac {21}{13}}

This is approximately 1.62 or 1.62:1. At this ratio, it means the drive gear (A) must make 1.62 revolutions to turn the output gear (I) once. It also means that for every onerevolution of the driver (A), the output gear (I) has made13⁄21 =1⁄1.62, or 0.62, revolutions. The larger gear (I) turns slower.

The third gear in the picture (B) hasN_B = 42 teeth. Now consider the gear ratio for the subset consisting of gearsI andB, with the idler gearI serving as the input and third gearB serving as the output. The gear ratio between the idler (I) and third gear (B)R_IB is thus

R_{IB}={\frac {N_{B}}{N_{I}}}={\frac {42}{21}}

or 2:1.

The final gear ratio of the compound system is1.62 × 2 ≈ 3.23. For every 3.23 revolutions of the smallest gearA, the largest gearB turns one revolution, or for every one revolution of the smallest gearA, the largest gearB turns 0.31 (⁠1/3.23⁠) revolution, a totalreduction of about 1:3.23 (Gear Reduction Ratio (GRR) is the inverse of Gear Ratio (GR)).

Since the idler gearI contacts directly both the smaller gearA and the larger gearB, it can be removed from the calculation, also giving a ratio of⁠42/13⁠ ≈ 3.23. The idler gear serves to make both the drive gear and the driven gear rotate in the same direction, but confers no mechanical advantage.

Double reduction gear

Double reduction gears

A double reduction gear set comprises two pairs of gears, each individually single reductions, in series. In the diagram, the red and blue gears give the first stage of reduction and the orange and green gears give the second stage of reduction. The total reduction is theproduct of the first stage of reduction and the second stage of reduction.

It is essential to have two coupled gears, of different sizes, on the intermediatelayshaft. If a single intermediate gear was used, the overall ratio would be simply that between the first and final gears, the intermediate gear would only act as anidler gear: it would reverse the direction of rotation, but not change the ratio.

Belt and chain drives

Bicycle with toothed belt drive to transmit torque from crank to rear sprocket

Special gears called sprockets can be coupled together with chains, as onbicycles and somemotorcycles. Alternatively, belts can have teeth in them also and be coupled to gear-like pulleys. Again, exact accounting of teeth and revolutions can be applied with these machines.

For example, a belt with teeth, called thetiming belt, is used in some internal combustion engines to synchronize the movement of thecamshaft with that of thecrankshaft, so that thevalves open and close at the top of each cylinder at exactly the right time relative to the movement of eachpiston. A chain, called atiming chain, is used on some automobiles for this purpose, while in others, the camshaft and crankshaft are coupled directly together through meshed gears. Regardless of which form of drive is employed, the crankshaft-to-camshaft gear ratio is always 2:1 onfour-stroke engines, which means that for every two revolutions of the crankshaft the camshaft will rotate once.

Automotive applications

Cutaway illustration of gears of an automotive transmission

Automobilepowertrains generally have two or more major areas where gear sets are used.

Forinternal combustion engine (ICE) vehicles, gearing is typically employed in thetransmission, which contains a number of different sets of gears that can be changed to allow a wide range of vehicle speeds while operating the ICE within a narrower range of speeds, optimizing efficiency, power, andtorque. Becauseelectric vehicles instead use one or more electric traction motor(s) which generally have a broader range of operating speeds, they are typically equipped with a single-ratioreduction gear set instead.

The second common gear set in almost all motor vehicles is thedifferential, which contains thefinal drive to and often provides additional speed reduction at the wheels. Moreover, the differential contains gearing that splits torque equally^{[citation needed]} between the two wheels while permitting them to have different speeds when traveling in a curved path.

The transmission and final drive might be separate and connected by adriveshaft, or they might be combined into one unit called atransaxle. The gear ratios in transmission and final drive are important because different gear ratios will change the characteristics of a vehicle's performance.

Valve timing gears on aFord Taunus V4 engine — the small gear is on thecrankshaft, the larger gear is on thecamshaft. The crankshaft gear has 34 teeth, the camshaft gear has 68 teeth and runs at half the crankshaft RPM.
(The small gear in the lower left is on thebalance shaft.)

As noted, the ICE itself is often equipped with a gear train to synchronize valve operation with crankshaft speed. Typically, the camshafts are driven by gearing, chain, or toothed belt.

Example

2004Chevrolet Corvette C5 Z06, six-speedmanual transmission
Gear	1	2	3	4	5	6	R
Ratio	2.97:1	2.07:1	1.43:1	1.00:1	0.84:1	0.56:1	−3.38:1

In first gear, the engine makes 2.97 revolutions for every revolution of the transmission's output. In fourth gear, the gear ratio of 1:1 means that the engine and the transmission's output rotate at the same speed, referred to as the "direct drive" ratio. Fifth and sixth gears are known asoverdrive gears, in which the output of the transmission revolves faster than the engine's output.

The Corvette above is equipped with a differential that has a final drive ratio (or axle ratio) of 3.42:1, meaning that for every 3.42 revolutions of the transmission's output, thewheels make one revolution. The differential ratio multiplies with the transmission ratio, so in 1st gear, the engine makes2.97 × 3.42 = 10.16 revolutions for every revolution of the wheels.

The car'stires can almost be thought of as a third type of gearing. This car is equipped with 295/35-18 tires, which have a circumference of 82.1 inches. This means that for every complete revolution of the wheel, the car travels 82.1 inches (209 cm). If the Corvette had larger tires, it would travel farther with each revolution of the wheel, which would be like a higher gear. If the car had smaller tires, it would be like a lower gear.

With the gear ratios of the transmission and differential and the size of the tires, it becomes possible to calculate the speed of the car for a particular gear at a particular engineRPM.

For example, it is possible to determine the distance the car will travel for one revolution of the engine by dividing the circumference of the tire by the combined gear ratio of the transmission and differential.

d={\frac {c_{t}}{gr_{t}\times gr_{d}}}

It is also possible to determine a car's speed from the engine speed by multiplying the circumference of the tire by the engine speed and dividing by the combined gear ratio.

v_{c}={\frac {c_{t}\times v_{e}}{gr_{t}\times gr_{d}}}

Note that the answer is in inches per minute, which can be converted tomph by dividing by 1056.^[7]

Gear	Distance per engine revolution	Speed per 1000 RPM
1st gear	8 in (200 mm)	7.6 mph (12.2 km/h)
2nd gear	11.5 in (290 mm)	10.9 mph (17.5 km/h)
3rd gear	16.6 in (420 mm)	15.7 mph (25.3 km/h)
4th gear	23.7 in (600 mm)	22.5 mph (36.2 km/h)
5th gear	28.3 in (720 mm)	26.8 mph (43.1 km/h)
6th gear	42.4 in (1,080 mm)	40.1 mph (64.5 km/h)

Wide-ratio vs. close-ratio transmission

This sectionpossibly containsoriginal research. Pleaseimprove it byverifying the claims made and addinginline citations. Statements consisting only of original research should be removed.(April 2009) (Learn how and when to remove this message)

This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Gear train" – news ·newspapers ·books ·scholar ·JSTOR(April 2011) (Learn how and when to remove this message)

Main article:Close-ratio transmission

A close-ratio transmission is a transmission in which there is a relatively little difference between the gear ratios of the gears. For example, a transmission with an engine shaft to drive shaft ratio of 4:1 in first gear and 2:1 in second gear would be considered wide-ratio when compared to another transmission with a ratio of 4:1 in first and 3:1 in second. This is because the close-ratio transmission has less of a progression between gears. For the wide-ratio transmission, the first gear ratio is 4:1 or 4, and in second gear it is 2:1 or 2, so the progression is equal to⁠4/2⁠ = 2 (or 200%). For the close-ratio transmission, first gear has a 4:1 ratio or 4, and second gear has a ratio of 3:1 or 3, so the progression between gears is⁠4/3⁠, or 133%. Since 133% is less than 200%, the transmission with the smaller progression between gears is considered close-ratio. However, the difference between a close-ratio and wide-ratio transmission is subjective and relative.^[8]

Close-ratio transmissions are generally offered insports cars,sport bikes, and especially in race vehicles, where the engine is tuned for maximum power in a narrow range of operating speeds, and the driver or rider can be expected to shift often to keep the engine in itspower band.

Factory four- or five-speed transmission ratios generally have a greater difference between gear ratios and tend to be effective for ordinary driving and moderate performance use. Wider gaps between ratios allow a higher 1st gear ratio for better manners in traffic, but cause engine speed to decrease more when shifting. Narrowing the gaps will increase acceleration at speed, and potentially improve top speed under certain conditions, but acceleration from a stopped position and operation in daily driving will suffer.

Range is the torque multiplication difference between 1st and 4th gears; wider-ratio gear-sets have more, typically between 2.8 and 3.2. This is the single most important determinant of low-speed acceleration from stopped.

Progression is the reduction or decay in the percentage drop in engine speed in the next gear, for example after shifting from first to second gear. Most transmissions have some degree of progression in that the RPM drop on the first–second shift is larger than the RPM drop on the second–third shift, which is in turn larger than the RPM drop on the third–fourth shift. The progression may not be linear (continuously reduced) or done in proportionate stages for various reasons, including a special need for a gear to reach a specific speed or RPM for passing, racing and so on, or simply economic necessity that the parts were available.

Range and progression are not mutually exclusive, but each limits the number of options for the other. A wide range, which gives a strong torque multiplication in first gear for excellent manners in low-speed traffic, especially with a smaller motor, heavy vehicle, or numerically low axle ratio such as 2.50, means the progression percentages must be high. The amount of engine speed, and therefore power, lost on each up-shift is greater than would be the case in a transmission with less range, but less power in first gear. A numerically low first gear, such as 2:1, reduces available torque in 1st gear, but allows more choices of progression.

There is no optimal choice of transmission gear ratios or a final drive ratio for best performance at all speeds, as gear ratios are compromises, and not necessarily better than the original ratios for certain purposes.

See also

Continuously variable transmission (CVT)
Epicyclic gearing - related toturboprop reduction gear boxes
Machine (mechanical)
Mechanism (engineering)
Outline of machines
Powertrain
Virtual work
Wheel train (horology)

References

^Army Service Corps Training on Mechanical Transport, (1911), Fig. 112
^Uicker, J. J.; G. R. Pennock; J. E. Shigley (2003).Theory of Machines and Mechanisms. New York: Oxford University Press.
^^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^jShigley, Joseph Edward; Mischke, Charles R. (1989)."13: Gearing—General".Mechanical Engineering Design (Fifth ed.). New York, New York: McGraw-Hill Publishing Company. pp. 527–584.ISBN 0-07-056899-5.
^Paul, Burton (1979).Kinematics and Dynamics of Planar Machinery. Prentice Hall.
^^a ^b ^cStandards and Curriculum Division, Bureau of Naval Personnel (1946)."6: Gears, a topic with teeth in it".Basic Machines. Washington, D.C.: Government Printing Office. pp. 65–79.
^"Why choose ring and pinion gears".amtechinternational.com. 5 December 2023.
^"Google: convert in/min to mph". Retrieved2018-11-24.Formula: divide the speed value by 1056
^Cangialosi, Paul (2001)."TechZone Article: Wide and Close Gear Ratios".5speeds.com. Medatronics.Archived from the original on 30 August 2012. Retrieved28 October 2012.

External links

Wikimedia Commons has media related toGear train.

v
t
e

Systems

Shapes

Geartooth profiles

Mechanics

Examples

Bicycles	Cogset Derailleur Hub gear Shaft-driven bicycle Sprocket
Horology	Wheel train

See also

Retrieved from "https://en.wikipedia.org/w/index.php?title=Gear_train&oldid=1293516193"

Hidden categories:

[8]ページ先頭

©2009-2025 Movatter.jp