Mechanics of self-rotating double-disc grinding process

Unlike most double-disc grinding processes, which use forced workpiece rotation, some double-disc processes rely on workpiece self-rotation driven by non-uniform shear forces resulting from partial wheel-workpiece coverage. This self-rotation is poorly understood, with workpiece angular frequency remaining unknown despite its importance. This paper investigates the kinematics of self-rotation via analytical modelling of the moment-equilibrium conditions, derived from experimentally determined specific-energy values. The model showed that workpiece coverage ratio is the dominant factor governing workpiece angular frequency, allowing for the choice of optimal workpiece coverage ratios that avoid (i) workpiece-stoppage and (ii) excessive frictional heat generation. The predicted velocity was validated with acoustic-emission measurements.