A method for estimating a temperature profile for individual combustion cans at an inlet of a gas turbine is disclosed. The rotary joint has a distributor and a center shaft, which includes two hollow cylindrical center shafts respectively inserted into a through hole from opposite front and back surface sides of a rotatable table. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members.