Question

The minimum number of teeth on the pinion to operate without interference in standard full height involute teeth gear mechanism with ${20}^o$ pressure angle is

• A. 14
• B. 12
• C. 18
• D. 32

Answer 1

The correct option is C 18

$Z_{min}=$ minimum no.of teeth on the pinion to avoid interference.

Since gear ratio is not given, we assumed that arrangement is rack & pinion arrangement.

$Z_{min}=\frac{2\times A_W}{si{n}^2\varphi }=\frac{2\times 1}{si{n}^{2}20}=17.09$

$\underset{–}{\sim }\text{18 teeth}$