(Solved): 4. Fig 4 illustrates a pair of standard spur gears with normal meshing. The module m=2.0, the press ...

4. Fig 4 illustrates a pair of standard spur gears with normal meshing. The module $m=2.0$, the pressure angle $=20^{?}$, and the number of teeth $Z_1=21,Z_2=73$. Calculate the radius of addendum two gears, as well as the tooth thickness $(s_1$ and $s_2)$, space width $(e_1$ and $e_2)$ and the center distance $a?\left(20^{?}\right)$