Suppression of the inflection pattern in ultraprecision grinding through the minimization of the hydrodynamic force using a toothed wheel

Abstract

Fluid coolant has been widely used for cooling, lubrication, and the removal of cutting chips in the grinding process; however, it can generate grinding marks due to the hydrodynamic force especially in case of a lack of the spindle stiffness. This leads to inflection patterns on the workpiece, with sub-micrometer level of waviness, which is quite critical in rotationally symmetric ultraprecision grinding. In this study, we propose the use of a toothed wheel which is remarkably efficient in suppressing the inflection pattern by minimizing the hydrodynamic pressure. A toothed wheel has a simple geometry with a peripheral surface similar to a saw. The teeth disturb the generation of the coolant flux layer and noticeably decrease the hydrodynamic force. Furthermore, the toothed wheel increases the net grinding force due to the tangential cutting edge.This study simulated the hydrodynamic pressure in the grinding process and validated the flat surface grinding results by varying the tooth geometry. A comparison showed that the hydrodynamic force was decreased by 20–35% and that the inflection pattern of the ground surface was markedly decreased in rotational symmetric grinding.