Research On Contact Characteristics Of Double Involute Gear

Double involute gears is a new type of gear, which combines the advantages of involute gear and double circular arc gears. The tooth profile consists of two involute curves, which are linked by a transitional curve and form the ladder shape of the tooth.The double involute gear avoid the defects of earlier node corrosion due to the tooth flank area without contact at the tooth waist. At the same time, the tooth root bending strength is improved due to the tooth root thickening. In recent years, the bending strength calculation of double involute gear has been intensively studied, but the study of contact strength of tooth surface is still a weak link. The contact strength calculation still uses contact strength calculation formula of common involute helical gear and It has been found that the large deviation was existed in practices. The contact strength was researched in the ideal state and the effect of the tooth surface friction on the tooth surface contact fatigue strength was ignored, so the development and application of double involute gear was restricted. In this paper, the contact characteristic analysis of double involute gear was conducted considering the effect of tooth surface friction and meshing stiffness, and the tooth surface friction characteristics and contact characteristics was studied. The concrete research contents as follows:(1) The simplified model of double involute gear is set up and the geometric characteristic of the model is analyzed. The meshing line length and the contact line length of double involute gear is calculated. The three-dimensional parametric model of the double involute gear is established based on the three-dimensional parametric modeling technology.(2) The static contact finite element model of double involute gear is established.The static contact finite element analysis is conducted. The distribution of gear tooth surface contact stress of this new type gear is analyzed comparing with involute gear.The static contact analysis of double involute gear is conducted by considering tooth surface friction and meshing stiffness and the influence of tooth surface friction and meshing stiffness on the static contact characteristics of double involute gear is analyzed.(3) The dynamic contact finite element model of double involute gear is established and dynamic contact finite element analysis of the double involute gear iscarried out. The dynamic contact characteristics of double involute gear is analyzed comparing with the static contact finite element analysis double involute gear. The dynamic contact analysis of double involute gear is carried out considering tooth surface friction and meshing stiffness, and the influence of tooth surface friction and meshing stiffness on dynamic contact stress of double involute gear is analyzed.(4) The contact fatigue analysis of double involute gear is carried out by using the finite element method and the contact fatigue property of the double involute gear is analyzed by comparing with the involute gear. The contact fatigue of double involute gear is analyzed by considering the tooth surface friction and meshing stiffness, and the influence of tooth surface friction and meshing stiffness on the contact fatigue life is analyzed.