Question

The root angle of a bevel gear is equal to

(a) pitch angle – addendum angle

(b) pitch angle + addendum angle

(c) pitch angle – dedendum angle

(d) pitch angle + dedendum angle

The question was posed to me in a national level competition.

The above asked question is from Worm Gears topic in section Toothed Gearing & Gear Trains of Machine Kinematics

Answer 1

The correct choice is (c) pitch angle – dedendum angle

The explanation: Root angle is the angle subtended by the root of the tooth at the cone centre. It is denoted by ‘θR’. It is equal to the pitch angle minus dedendum angle.