(Solved): 1. A stock helical gear has a normal pressure angle of 20, a helix angle of 25, and a transve ...

1. A stock helical gear has a normal pressure angle of $20^{?}$, a helix angle of $25^{?}$, and a transverse diametral pitch of 4 teeth/in, and has 12 teeth. Find: 1.1 The pitch diameter 1.2 The transverse, the normal, and the axial pitches (6) 1.3 The normal diametral pitch 1.4 The transverse pressure angle (2) 1.5 The smallest tooth number $\left({\mathrm{N}}_{?}\right)$ of a helical-spur pinion that will run without interference with a gear with the same number of teeth. (8) [20] Question 2 \{Chapter 14\} 2. In a set of spur gears, a 300-Brinell 18-tooth 16-pitch $20^{?}$ full-depth pinion meshes with a 64-tooth gear. Both gear and pinion are of grade 1 through-hardened steel. Using $?=$ $?0.032,J_P=0.32$ and $J_G=0.41$ respectively. Calculate: 2.1 The pinion strength of the steel $\left(S_t\right)p$ 2.2 The gear strength of the steel ${\left(S_t\right)}_G$ 2.3 The hardness of the gear ${\left(H_B\right)}_G$ [10]