(Solved): -75 A 21-tooth pinion rotating at 1500rpm meshes with a 35 -tooth gear in a spur gear reducer. Bot ...

-75 A 21-tooth pinion rotating at $1500\mathrm{rpm}$ meshes with a 35 -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 $10\mathrm{kN}$. Conditions are such that $K_m=1.7$. It is proposed that standard $25^{?}$, full-depth teeth be used, with both pinion and gear hobbed from an AISI 4140 nitrided steel. The module is 4 and the face width $50\mathrm{mm}$. Estimate the number of cycles of bending stress (using the AGMA equations) that the gearset can withstand.