Question

The angle between a tooth profile and a radial line at its pitch point is known as

(a) pressure angle

(b) dedendum angle

(c) spiral angle

(d) none of the mentioned

I had been asked this question in a national level competition.

The question is from Gearing in chapter Toothed Gearing & Gear Trains of Machine Kinematics

Answer 1

Correct answer is (a) pressure angle

Explanation: The angle subtended at the centre of a base circle from the origin of an involute to the point of tangency of the generatrix from any point on the same involute is known as roll angle.

The angle between a tooth profile and a radial line at its pitch point is known as pressure angle.