Stability and dynamics of parallel plunge grinding

To improve the performance of conventional cylindrical plunge grinding processes, this paper introduces parallel grinding which employs an extra grinding wheel opposite to the original one, simultaneously cutting workpiece. Depending on the relative location of the two wheels, the cutting areas are divided into non-overlapped and overlapped zones. In the overlapped zone, the two wheels mutually interact with each other via the regenerative effect in the workpiece surface. Due to the newly introduced wheel, the static elastic deflection of the grinding system is significantly reduced so that the geometry accuracies of components can be improved. Meanwhile, it is found by linear analysis that the grinding stability and cutting efficiency can be largely improved by the parallel grinding when the two wheels are partially overlapped. Moreover, nonlinear analysis reveals unsafe cutting in the parallel grinding process, where loss of contact may take place either in the non-overlapped or in the overlapped cutting zones. As a result, the area of unsafe zones is shrunk by the parallel cutting method, which enhances the grinding safety.