2) Why dedendum is larger than addendum? Meshing of mating teeth should occur on the involute portion of teeth. The teeth have involute profile from the base circles to addendum circles. ... To avoid this bottom land of gears are lowered such that it lies on the periphery of the dedendum circle.

Why is Dedendum value more than addendum?

Why dedendum Value is more than addendum value? In order to get clearance between the teeth of one gear and bottom surface of mating gear so as to avoid interference, dedendum is having more value than addendum.

Which is larger addendum or Dedendum?

DEDENDUM (b) is the depth of a tooth space below the pitch line. It is normally greater than the addendum of the mating gear to provide clearance. DIAMETRAL PITCH (P) is the ratio of the number of teeth to the pitch diameter.