Preview:Hertz Gear Tooth Contact Stress Calculator The Hertz theory equation assumes an elliptic stress distribution σo= {( W ( 1 + rp1/ rp2) )/( rp1F π [ ( 1 - v12) / E1+ ( 1 - v22) / E2] sinφ )}0.5 Where: σo= Maximum value of contact stress (N/mm2) W = force ...