A 21-tooth pinion rotating at 1800 rpm meshes with a 33-tooth gear in a simple spur gear set. 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 Km = 1.7. It is proposed that standard 25-degree, full-depth teeth be used, with both pinion and gear hobbed from an AISI 4140 nitride steel. The diametral pitch is 6, and the face width 2.000 in.
(a) Determine the bending stress using the AGMA equations (for the gear most likely to fail).
(b) In the gearset, which do you expect to fail first - the pinion or the gear?
(c) Determine the pitch diameter of the pinion and pitch-line velocity of the gearset.
(d) Determine the dynamic factor K_v.
(e) Determine the bending geometry factor (J) and application factor.
(f) Determine the size factor (K_s), rim thickness factor (K_B), and idler factor (K_1).
(g) Determine the pinion-tooth bending stress How would you determine the factor of safety? Describe qualitatively.