Analysis and optimization of time-varying meshing parameters of spiral bevel gear with consideration of load sensitivity

The dynamic response of automotive transmission systems is significantly influenced by the meshing behavior of spiral bevel gears, which are subject to load variations. This paper establishes a meshing model considering load sensitivity to explore the relevant meshing parameters of spiral bevel gears that change with load during the meshing process. Load-bearing Tooth Contact Analysis (LTCA) is then performed using this model to analyze the impact of loading torque on meshing parameters. The actual contact ratio calculation method is discussed, and the time-varying meshing stiffness curve of the gear pair can be obtained. The investigation demonstrates that the meshing stiffness is higher in meshing intervals with a larger contact ratio, which is vital for the robustness of gears under different loads. Based on these findings, an optimization strategy has been developed for the actual contact ratio of the gear pair. The manipulability of tooth surface geometry is leveraged to optimize the angle η between the contact trajectory of the gear tooth surface and the tooth root by adjusting the direction of the tooth surface contact path to achieve the goal of the contact ratio optimization, and the sensitivity of installation errors and friction before and after optimization are analyzed. Simulation results indicate a certain difference between the theoretical and actual contact ratio, and the introduction of the actual contact ratio into dynamic analysis will ensure the more accurate calculation. As the load increases, the actual contact ratio and time-varying meshing stiffness will be increased accordingly, leading to an improved load distribution coefficient and reduced fluctuation values of time-varying meshing stiffness, which promotes transmission stability. This study provides an in-depth analysis of the meshing behavior of spiral bevel gears under varying loading conditions. The findings offer valuable guidance and application for subsequent research on dynamic response of automotive transmission system.