An epicyclic gear train shown in Fig. 15.29, consists of two sun wheels A and D with 28 and 24 teeth respectively, engaged with a compound planet wheels B and C with 22 and 26 teeth. The sun wheel D is keyed to the driven shaft and the sun wheel A is a fixed wheel coaxial with the driven shaft. The planet wheels are carried on an arm E from the driving shaft which is coaxial with the driven shaft. Find the velocity ratio of gear train. If 1.2 kW is transmitted and input speed is 120 rpm, determine the torque required to hold the sun wheel A. E Fig.15.29 Epicyclic gear train