Torque on Gears in Epicyclic Gear Train:

An epicyclic gear train consists of various gears and an arm. The power input might be through a gear or arm and likewise power output may also be through an arm or a gear.

Assume T_i and T_o be input and output torques at equivalent input speed N_i and output speed N_o, respectively.

Let T_h be the torque on a fixed gear. As gear train is in equilibrium

 T_i  + T_h  + T_o  = 0                              . . . (10.10)

If there is no power loss

T_i N_i  + T_h N_h  + T_o N_o  = 0                        . . . (10.11)

As speed of fixed gear N_h = 0.

Hence,

T_i N_i  + T_o N_o  = 0 . . . (10.12)

From equations. (10.10) & (10.12) desired quantity may be resolute. The speed of the output shaft No may be resolute by tabular method or algebraic method. Hence, from the given power and speed T_i and T_o can be resolute.

Therefore, from known values of T_i, T_o, N_i & N_o value of torque on fixed gear T_h may be resolute.