Learn Engineering - Turboshaft

Hey @TLAR care to weigh in?

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Pretty cool video there!

One key difference is the engine output shaft of most us military helicopters is connected to a “nose” gearbox that then connects to the main transmission via a shaft.
For example : An Apache has 2 driveshafts (main rotor), A Chinook has 7

What?! The wiki didn’t explain.

Apache has 1 short driveshaft from the each of the engines(2 very short - less than a foot long) shafts) - to the main transmission
Chinook has a similar set up plus the 5 driveshafts that go from the main xmsn in the rear to the front to drive the second xmsn & set of blades.

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Does this help clarify?

:smile:


Also, wouldn’t the Apache have a 3rd to the tail rotor transmission and a 4th to the tail rotor, um, other transmission (both are really more gearboxes, I presume, to turn the rotation 90ish degrees)?
https://www.wallpaperup.com/321969/AH-64_APACHE_attack_helicopter_army_military_weapon_(29).html

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I need further clarification. No matter how I slice it, the most I count is 6 shafts on the CH47

The CH47’s I had the “pleasure” of working on and riding in had (If memory serves me) had 5 leading to the forward xmsn, two to the rear and the two short ones from the engine / nose gearboxes to the combo xmsn

synchronizing the rotors was a tedious gig