Automatic Transmission, How it works ?

Some technologies are easier to understand

with the help of 3D animation

But, What about the 6-Speed Automatic transmition from Allison

To visualize and understand

This beautiful planetary gearset mechanism

A 2D Animation will be ideal

You can consider this 2D drawing as a cross section of the 3D model

A planetary gearset has 2 inputs and 1 output

If you properly understand working of a planetary gearset

You can easily understand automatic transmitions from the 2D animation

the essence of the planetary gearset is
that just by giving

different speeds to the ring and sun
gears you will be able to get different

speeds at the output

the beauty of automatic transmissions
lies in how these different input speeds

are transmitted

let's see it in the 2D animation

this 3D planetary set is represented in 2D as shown

in an automatic transmission the input
and the output are not directly

connected they are connected through an
intermediate shaft as shown

now a small suggestion before you
proceed you will be able to explain all

seven gears by yourself by pausing the
video for a moment and understanding the mechanism

please try that at every single gear you
will be amazed by the brilliance of this mechanism

if you press clutch see one the input
will be connected to the sun gear if you

press clutch C5 the output rain gear
will be stationary

this will result in the first gear

now let's add one more gear set here
comes the tricky part

the carrier of this set is connected to
the ring gear of the first set

this simply means that the output of the
second set is connected to the input of the first set

think for a moment about what happens
when you apply C1 and C4

Since C4 is applied the ring gear of
the second set will be stationary

this makes the carrier turn this carrier
is connected to the ring gear of the first set

so the ring gear of the first set will
also turn

this in turn will increase the output speed

or we will get the second
gear

to obtain a fourth gear or direct drive
a rotating clutch module is also used

we know that for a direct drive both the
Sun and the ring gear should rotate at

the input speed

if we press C2 and C1 together

this is what happens

in the very same mechanism if you apply
C2 and C4 you will get very high speed

at the output think for a moment and try
to understand this

it is clear that the carrier of the
second set will turn at the input speed

however here the ring gear is stationary

this makes the sun gear

turn at almost three times the
speed of the input

eventually a very high output speed is
obtained

one more gear set is used to obtain the
remaining gear ratios

however the sun gear of this set is not
connected to the shaft

instead it is connected to the rotating
clutch module

so this sun gear will always turn at the
input speed

and here again the output of

the set is connected to the input of the
adjacent set

for the remaining gear ratios C3 is
always applied this means that the brown

carrier or ring gear of the second set
will turn at one-third of the input

speed for the remaining cases

for the third gear apply see one as well

for the fifth gear apply C2 along with C3

the reverse is an interesting mechanism

here C5 is applied along with C3

so here the carrier of the second set is
stationary

this means that the planet gears of this
set will not be able to revolve

and that they will simply spin

this spin is in the same direction as
the input this planetary spin will make

the corresponding sun gear spin in the
opposite direction as a result

the output sun gear will also turn in the
opposite direction and we will get

the tereverse gear

we hope that you enjoyed the brilliance
of the allison transmission mechanism to

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