It is a type of gear train,with a basic idea about it !! thank you!!!!

1. EPICYCLIC GEAR TRAIN
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BY:
 KAMAL SIHAG

2. EPICYCLIC OR PLANETARY GEAR
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3. Epicyclic gearing or
planetary gearing is a gear
system consisting of one or
more outer gears, or planet
gears, revolving about a
central, or sun gear.
Typically, the planet gears are
mounted on a movable arm
or carrier which itself may
rotate relative to the sun gear.
Epicyclic gearing systems also
incorporate the use of an
outer ring gear or annulus,
which meshes with the planet
gears.
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4. Gears
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Epicyclic Gear train
Epicyclic means one gear
revolving upon and around
another. The design involves
planet and sun gears as one
orbits the other like a planet
around the sun. Here is a
picture of a typical gear box.
This design can produce large gear ratios in a small space and are
used on a wide range of applications from marine gearboxes to
electric screw drivers.

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Epicyclic Gear train
It is the system of epicyclic gears in which at least one wheel
axis itself revolves around another fixed axis.

6. Epicyclic Gearset
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An epicyclic gear set has some gear or
gears whose center revolves about
some point.
Here is a gearset with a stationary ring
gear and three planet gears on a
rotating carrier.
The input is at the Sun, and the output
is at the planet carrier.
The action is epicyclic, because the
centers of the planet gears revolve
about the sun gear while the planet
gears turn.
Finding the gear ratio is somewhat
complicated because the planet gears
revolve while they rotate.
INPUT
CARRIER
Ring
Planet
Sun

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Planetary Gear Train (Epicyclic Gear Train)

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Planetary Gear Train…
 In this train, the blue gear has six times the diameter
of the yellow gear
 The size of the red gear is not important because it is
just there to reverse the direction of rotation
 In this gear system, the yellow gear (the sun)
engages all three red gears (the planets)
simultaneously
 All three are attached to a plate (the planet carrier),
and they engage the inside of the blue gear (the ring)
instead of the outside.

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Planetary Gear Train…
Because there are three red gears instead of one,
this gear train is extremely rugged.
planetary gear sets is that they can produce
different gear ratios depending on which gear
you use as the input, which gear you use as the
output, and which one you hold still.

10. DRAWING OF PLANETARY GEAR
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11. ADVANTAGES
 Compared to conventional gearboxes has
smaller dimensions
 Easier to sort through the constant rounds of
shot
Greater durability than conventional bikes in
gear
 Easy to achieve high transmission ratio due to
the size
They have higher gear ratios.
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12. DISADVANTAGES
More expensive than conventional production of
gearboxes
More complex than conventional transmission
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13. APPLICATIONS
These are used in back gear of lathe, hoists, pulley
blocks, wrist watches etc…
They are popular for automatic transmissions in
automobiles.
They are also used in bicycles for controlling power
of pedaling automatically or manually
.
They are also used for power train between internal
combustion engine and an electric motor
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