Subtopic: Design and selection of machine elements – gears, pulleys, chains and sprockets and belts
Question Statement:
In bevel gears used in right-angle tractor drive gearboxes, the pitch angle $\gamma$ of a bevel pinion meshing at $90^\circ$ shaft angle with a gear is given by:
Options:
(A) $\tan \gamma = z_1 / z_2$
(B) $\sin \gamma = z_1 / z_2$
(C) $\cos \gamma = z_1 / z_2$
(D) $\tan \gamma = z_2 / z_1$
Answer Key:
A
Step-by-Step Solution & Explanation
For orthogonal bevel gears ($\Sigma = 90^\circ$), $\tan \gamma_1 = \frac{z_1}{z_2}$ and $\tan \gamma_2 = \frac{z_2}{z_1}$.