Research On Minimum Film Thickness Of Tooth Surface In Grinding Face-Gear Drive

Abstract:Face-gear drive is a new type of gear transmission, it has many unique advantages. Its transmission efficiency and longevity greatly depends on the lubrication performance. The minimum film thickness, an important parameter in the lubrication analysis, has a close relationship to roughness height of tooth surface, it and their relationship not only directly affect carrying capacity and service life, but also are the important reasons for the failure of tooth, such as wear and scuffing. This paper studies minimum lubricant film thickness of tooth surface in grinding face-gear.In the geometric modeling of face-gear, according to the processing method and meshing theory, the equations of the face-gear tooth surface and fillet surface are deduced. In order to avoiding undercutting and addendum becoming to a point, effective tooth width of face-gear is made. The geometric models of pinion and face-gear are established.In the tooth contact finite element analysis(FEA) of orthogonal face-gear, three different finite element models of seven meshing teeth are established. By non-linear contact FEA with ABAQUS, the change rule of contact pressures and contact areas in three models are got. At the same time, the normal contact force of middle tooth in model, calculated by contact pressure and contact area, Provide condition for studying on the minimum lubricant film thickness in face-gear drive.In the minimum lubricant film thickness in grinding face-gear, based on the face-gear generation process, the tooth surface curvature of face-gear is obtained, the equation of the contact points on the face gear is deduced. According to differential geometry theory, the principal curvatures of the contact points on the pinion and the face gear are calculated. The tooth surface Entrainment speed of orthogonal face-gear drive is achieved. Based on Dowson-Higginson equation, this article obtains minimum film thickness of smooth tooth surface in meshing process. According to the effect of grinding method to surface topography, the minimum film thickness correction factor is recommended, this paper analyzes minimum film thickness of lubrication in the tooth surfaces considering diverse rough surface. In the Meshing characteristics test experiment of orthogonal face-gear pair, The meshing track, contact pressure and transmission error of face-gear drive have been detected, Which show theoretical calculation and related simulation results in front are right. This study provide important basis for design and lubricant deficiency analysis of face-gear.