Research On The Stress And Experiment Of Novel Torus-Involute Gears

Novel torus-involute gears are not sensitive to installation errors and have a good meshing performance without teeth modification. The contact stress and bending stress of torus-involute gears are important factors affecting their life span and the research on the stress of torus-involute gears is the foundation of the promotion of this kind of gears. The main content of the research on the contact and bending stress of torus-involute gears is shown as follows:(1)According to the gear cutting process and the theory of meshing, the tooth profile equations of torus-involute gears are derived. Based on the tooth profiles equations, the geometric characteristics of torus-involute gears are analyzed and the graphical user interfaces of the geometric characteristics of torus-involute gears are developed using MATLAB.(2)The mathematic contact model of torus-involute gears is established under standard installation and the tooth contact analysis is performed. The principal directions and curvatures of the rack cutters are studied and according to the relations between principal curvatures of mating surfaces, the principal curvatures of torus-involute gears are fumulated. The analytic method to calculate the maximum contact stress of torus-involute gears is provided based on the Hertz point contact theory. The effect of different modification coefficients on the tooth shape coefficient and the stress modification factor are analyzed and the rough method to calculate the root bending stress of different torus radius are provided based on the traditional cantilever theory.(3)According to the mathematic models of torus-involute gears, the accurate 3D models of torus-involute gears are bulit and the interference of torus-involute gears is checked. The finite element analysis of torus-involute gears under standard installation is performed and the contact ratio of torus-involute gears via the dynamic FEA.(4)The test rig of torus-involute gears is designed and the experiments of static bending stress of torus-involute gears under different loads on the tooth crest are performed. The testing results, the analytic results and FEA results of bending stress are compared, and the reasons for the experimental errors are studied.