Traceable form parameter evaluation of involute gear flank surfaces

Abstract Accurate and traceable surface form measurement of gears is crucial for high-value applications like automotive and wind energy. Traditional 1D measurements are insufficient for capturing complex manufacturing deviations. This work proposes deriving traceability for 2D surface form measurements from established 1D parameters, assuming similar uncertainty contributions. Preliminary validation includes 22 weekly repeat measurements and a 5-measurement repeatability study on a UK master gear traceable to Physikalisch-Technische Bundesanstalt, Germany. The flank surface is constructed by stitching line measurements and evaluated using the Chebyshev polynomial areal surface parameter method, extended for robust fitting. This method accommodates both optical and tactile data, allowing direct comparison between traditional and emerging optical techniques in future works. Uncertainty budgets were calculated for each surface form parameter (U95 = ±2 μm) and their traceable 1D parameter (U95 up to ±1.4 μm) and are discussed. Data stitching had the largest contribution to surface form parameter uncertainties (U95 = ±0.79 μm), followed by the traceable 1D parameter. This framework for 2D surface measurement, derived from 1D equivalents, lays the groundwork for improved gear evaluation methodologies. Future work will refine uncertainty quantification, investigate optical measurement capabilities, and further validate the approach for broader industrial adoption.