Approximation model for longitudinal-crowned involute helical gears with flank twist in continuous generating grinding

Longitudinal-crowned involute helical gears perform better in load capacity and can improve transmission quality. When longitudinal crowning of helical gears is processed with continuous generating grinding, the flank twist occurs and reduces the transmission stability of gears. In the paper, an innovative approximation model is proposed to demonstrate the relationships between the flank twist and parameters (including gear parameters and modification parameters) in a simple mathematical form. The flank twist calculated by the approximation model is compared with that calculated based on the gear meshing principle. The comparison results confirm that the model is right. Based on the new model, the influences of gear parameters on the flank twist are analyzed. The model can reduce the flank twist in the gear design.