Efficiency of 2 d.o.f. planetary gear trains

[inazio]

Hello all,
I need to calculate the theorical efficiency of some 2 degrees of freedom planetary gear trains. I have found some different methods, but all of them calculate the efficiency of the basic 2 dof planetary gear train in which the planet link is taken as an input or an output link.
I would like to calculate the efficiency of 2 dof planetary gear trains with 5 and 6 links.
Do you know wich methodology could I use to calculate it?
Regards

 

[volpegrigia]

try "G. Henriot - Planetary gear trains". He has a complete tratise on the subject.

 

[inazio]

Thank you volpegrigia,
Henriot has a method to calculate the efficiency of simple 2 dof planetary gear trains.But unfortunately, the book I have found is in french.
I have calculated the efficiency of four 2 dof simple planetary gear trains using the method of Merritt. This method can be found in his books: Gears and Gear Trains.
A simple 2 dof planetary gear train, takes 2 sun gears and the carrier as the input/output links.
Now I need to calculate the efficiency of two compound 2 dof planetary gear trains. A compound planetary gear train is an assembly of two simple gear trains. On it, the carrier is not an input/output link and it belongs to both of the simple gear trains. I have thought to calculate the efficiency of the compound train, mutiplying the efficiency of the two simple trains independently, but I think that that can`t be done.
Do you know of any method available to obtain the efficiency of 2 dof compound planetary gear trains?
Regards