Interference in Internal Involute Spur Gears

Abstract

This paper deals with the interference in internal involute spur gears and shows, giving the pressure angle α and the addendum (for module) ρ₁, ρ₂, that the minimum tooth difference to avoid the trochoidal interference is nearly equal to (ρ₁+ρ₂)cosec²δ and that of avoiding the trimming is nearly equal to 2 (ρ₁+ρ₂)cosec²δ where (2δ-sin 2δ)/2sin²δ=tanα Results of numerical calculation for standard gears are also shown.