The combinedmesh stiffness of spiralbevel gearsis oneimportant factorfordynamic analysis. The total deflection on the contact line of a tooth pair is composed of bending, shear and tooth contact deflections. The bending and shear deflections on the contact line of the gear tooth are evaluated by the finite element method with isoparametric shell elements, and the tooth contact deflections are evaluated using Hertzian contact theory. Based on these deflections, the stiffness is obtained using the so called flexibility method, and then the combined mesh stiffness is obtained by applying
the contact and load sharing ratios.