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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