1.       A 21-tooth pinion rotating at 1800 rpm meshes with a 33-tooth gear in a spur-gear reducer. Both pinion and gear are manufactured to a quality level of 9. A reliability of 0.9 has been specified, and the transmitted tangential load is 2800 lb. Conditions are such that Cm = 1.7. It is proposed that standard 25°, full-depth teeth be used, with both pinion and gear hobbed from an AISI 4140 nitrided steel. The diametral pitch is 6, and the face width 2.0 in. Estimate the number of cycles of contact (surface) stress (using the AGMA equations) that the gearset can withstand.

2.       If the gearset in Problem 12-46 transmits 7.5 kW at 1750 input pinion rpm, find the torque on each of the three shafts.