Wear evolution and service life prediction of small-diameter ball-end grinding wheels during hemispherical resonator grinding

During the trajectory grinding of hemispherical resonators, the grinding points of the small-diameter ball-end diamond wheel continuously migrate along the complex curved surface, resulting in dynamically changing grinding conditions. This dynamic variation induces non-uniform wheel wear, ultimately leading to form errors on the workpiece surface. To gain an in-depth understanding of the influence of wheel wear on form error, a theoretical model of wheel wear in hemispherical resonator grinding was established. The spatial distribution characteristics of wear points and the influencing factors of wheel wear were systematically analyzed, and the evolution law of wheel wear throughout the full grinding cycle was revealed. Furthermore, a model describing the effect of wheel wear on the form error of hemispherical resonators was developed to clarify the mechanism of form error formation. Grinding experiments showed that the deviation between the theoretical and measured wheel wear values was less than 9.64%, while the error rate of form accuracy ranged from 2.42% to 7.62%. Based on the established wheel wear and form error models, a support vector machine prediction model was constructed to predict form errors and evaluate wheel service life under various grinding parameter combinations. The reliability of the wheel life evaluation results was verified through comprehensive analyses of form error characteristics, wheel wear morphology, and workpiece surface quality. Overall, this study develops a unified framework that integrates wheel wear evolution, wear-induced form error formation, and rapid prediction of form error and wheel life in hemispherical resonator grinding, thereby supporting form error control, grinding parameter optimization, and wheel condition management.