Question

Involute profile is preferred to cyloidal because

(a) the profile is easy to cut

(b) only one curve is required to cut

(c) the rack has straight line profile and hence can be cut accurately

(d) none of the mentioned

This question was posed to me during an interview.

My question is based upon Toothed Gearing topic in portion Toothed Gearing & Gear Trains of Machine Kinematics

Answer 1

Correct option is (b) only one curve is required to cut

The best I can explain: The face and flank of involute teeth are generated by a single curve where as in cycloidal

gears, double curves (i.e. epi-cycloid and hypo-cycloid) are required for the face and flank respectively.

Thus the involute teeth are easy to manufacture than cycloidal teeth. In involute system, the basic rack has straight teeth and the same can be cut with simple tools.