Thermal behavior of spiral bevel gears

A study of the thermal behavior of spiral bevel gears is presented. The study includes both experimental and analytical results. Experimental data was taken using thermocoupled test hardware as well as an infrared microscope. Many operational parameters were varied to investigate their effects on the thermal behavior. The data taken was also used to validate the boundary conditions applied to the analytical model. A finite element based solution sequence was developed. A three-dimensional model is based on modeling the manufacturing process for these gears. Contact between the meshing gears is found using tooth contact analysis to describe the location, curvatures, orientations, and surface velocities. This information is then used in a three-dimensional Hertzian contact analysis to predict contact ellipse size, and maximum pressure. From these results an estimate of the heat flux magnitude and location on the finite element model are made. The finite element model uses time averaged boundary conditions to permit the solution to attain steady state in a computationally efficient manner. Then time and position varying boundary conditions are applied to the model for analysis of the cyclic heating and cooling due to the gears meshing and transferring heat to the surroundings respectively. The model is run in this mode until the temperature behavior stabilizes. The transient flash temperature on the surface is therefore described. The analysis can be used to predict overall expected thermal behavior of spiral bevel gears. The experimental and analytical results were compared for this study and to a limited number of other studies. The experimental and analytical results were basically within 10% of each other for the cases compared. The experimental comparison was for bulk thermocouple locations and data taken with an infrared microscope. A limited number of studies that the results attained herein were compared to predicted the same basic behavior.