In testing the fatigue behavior of gears, the illustrated system of gears and shafts is frequently employed. The parts are made so that in assembly it is necessary to hold one of the 75 mm gear stationary and rotate the corresponding 125 mm gear through a 3° angle in order to get the gears to mesh. There is a "locked-in " torque in the system, and when the system is driven by application of an external torque to one of the gears, the system of gears and shafts constitutes a power loop in which the average power is much larger than the externally supplied power. 

Calculate the maximum shear stresses in the two shafts after they are assembled but before external torque is applied. The shafts are made of 1020 CR steel.

Answer rating: 100% (QA)

To calculate the maximum shear stresses in the two shafts after they are assembled but before external torque is applied we can use the following steps 1 Calculate the angle of twist for the system of ... View the full answer