A 50-tooth spur gear is in mesh with a 27-tooth pinion. Thegears have a diametral pitch of 5 teeth/in, and a pressure angle ofφ = 25°. The gears transmit 80 HP at 4000 pinion rpm.
Find the factors of safety against bending and surface failure.Assume that the teeth are full depth, Qv = 10, a through hardenedto 360 HB steel gear, and a carburized and case hardened steelpinion. Assume a face width of 3.0 in, a 99.9% reliability, and alife of 9 5 10 × cycles.
