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Hi everybody,
I've got a simple question, but for me it's no so clear.

We have an input shaft to the gearbox (only 1 transmission ratio)and an output shaft.
Then ,which are the forces in the reaction arms of the gearbox?.
Do they take the whole input torque? or, do they take the difference between the input and output torque?, or
something in the middle?.

Thank you very much to everyone.


If the input and output shaft are parallel and rotating in opposite directions, then the torque on the gearbox will be the output torque minus the input torque.
If the shafts are rotating in the same direction (eg a two or four stage unit then the reation torque will be in plus out.
If the shafts are at an angle then vectors come into the equation


Whatever mike bull has write, is absolutely correct.


Being pedantic Mike, your answer assumes input and output shaft are co-axial. Any other arrangement (ie single pass spur 'box) would require vector calculations based on relative shaft centre positions.


Thank you very much to all of you.
I were investigating on the issue, and for my situation,
3 stage gearbox : 1st - planetary, 2nd and 3th stages - parallel, I made some figures regarding the diameters of the gears, and I concluded that the reaction arms took
aprox. the 82% of the input torque.
Thanks a lot.

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