Spiral Bevel Gear Loaded Contact Analysis And Mesh Stiffness Finite Element Method Study

The performance of spiral bevel gear is affected by its strength and stiffness seriously, transmission error and mesh stiffness directly affect the dynamic mechanical characteristics of working life and noise. The geometric model of spiral bevel gear is studied, finite element modeling method and the boundary conditions are set in the software of ABAQUS. The strength and stiffness of spiral bevel gear are analyzed based on the finite element method. Research in this paper is of significance to the design and manufacturing of spiral bevel gear that has a requirement of high performance.Main contents and methods of this paper are as follows:1. The geometric model and finite element model of spiral bevel gear are studied.Based on the machining theory of spiral bevel gear, theoretic points on tooth surface is gained via numerical calculation, thus the three-dimension solid model of the tooth is made by reconstructing tooth surface with NURBS surface.45 points on the reconstructed tooth surface is compared with the data calculated by software from Gleason, which confirms the accuracy of the reconstructed tooth surface.Hexahedral mesh grids are structured by combinedly using the software of ABAQUS and CATIA, and the accuracy of investigating LTCA with this method is analyzed. The preprocessing method and key technologies used in the software of ABAQUS while conducting LTCA are given.2. Via using the method of Loaded Tooth Contact Analysis (LTCA), parameters related to the strength of spiral bevel gear have been calculated in the thesis and the influence law of load on the parameters has been analyzed.In the thesis, the contact stress, bending stress on the root and the contact force on the tooth have been calculated by Finite Element Method (FEM). The tooth contact trajectory, the transmission error, the contact ratio and the distribution factor of load can be obtained each by the cloud map of contact stress and angle change. The computing method of each parameter and the influence law of loads on them has also been analyzed.3. Taking manufacturing errors, mounting errors, axial deformation and bearing stiffness into account, LTCA has been conducted, and its result has been compared with the one attained by Tooth Contact Analysis (TCA) in the thesis.4. The time-varying mesh stiffness of spiral bevel gear has been calculated.Based on the principal of LTCA, the thesis investigates the following contents:method of calculating the mesh stiffness of spiral bevel gear, the disposal method of correlation parameters, single-tooth mesh stiffness and multi-tooth mesh stiffness gained by analyzing the normal contact force and the elastic deformation in the software of ABAQUS, the influence law of load on the stiffness curve. The result shows that load has a great effect on the magnitude and cycle time of the stiffness curve. It should be noted that load has an impact on the contact ratio and the contact position.