Comparison of Skin Model representations and Tooth Contact Analysis techniques for Gear tolerance analysis

Abstract

To improve the tolerancing process in an industrial context, there exists a strong need for tolerance analysis to estimate the ppm (defected product per million - probability of scrap) in an acceptable computer time and managing the accuracy of the results. The developed approaches for gear tolerance analysis based on simulation, depend on the type of geometrical model - the Skin Model representation, and on the type of behavior model, which impact the accuracy of the results and the computer time of the simulation. Therefore, this paper proposes a comparison of four Skin Model representations (discrete shape, discrete shape with Vectorial Dimensioning & Tolerancing (VD&T), parametric surface, parametric surface with VD&T), and three Tooth Contact Analysis (TCA) techniques based on minimization of the distance between the two discrete representations of the two teeth, minimization of the distance between the two projected discrete representation in the meshing plane, simulation of tangency of tooth surfaces with a continuous representation being in mesh, regarding accuracy of results, computation time and the adequacy with the standard tolerance practices. The assessment of the accuracy of the results is based on a comparison between the numerical simulation results and the experimental results, and a comparison with the literature results. The assessment of the adequacy with the standard tolerance practices is based on the mapping between the parameters of the Skin Model representation and the standardized tolerances.