Design a pair of standard spur gears for transmitting 60 hp from a 5200-rpm motor to a 1300-rpm machine. A safety factor of 1.2 should be used, together with 99% reliability and a life of 107 pinion revolutions at full load (with the remaining lower-load cycles being negligible). It is important to minimize size and weight. Use case-hardened alloy steel gears of 660 Bhn (pinion) and 600 Bhn (gear), and use Table 15.5 to estimate surface fatigue strength. Specify an appropriate combination of diametral pitch, numbers of teeth, center distance, face width, and level of manufacturing accuracy.
