Centerless grinding process and apparatus therefor

摘要

In a method for minimizing the roundness error in an workpiece having a generally circular periphery during centerless grinding of the workpiece, the workpiece is rotatably supported on the upper surface of a first workpiece support between the grinding wheel and the second workpiece support, with the first support rotatably supporting the workpiece in contact with said grinding wheel and said second support. The alpha -setup angle and beta -setup angle cooperate with a cutting ratio to define the transfer function of a lobing loop system in the complex u-plane, and the lobing stability of the lobing loop system is thereby determined. The workpiece is rotated against the rotating grinding surface of the grinding wheel, and the magnitude and frequency of grinding disturbances causing the roundness error in the workpiece are detected. The beta -setup angle is modified to minimize the workpiece roundness error by minimizing the response of the lobing loop system corresponding to the detected grinding disturbances, and the ratio of the rotational speed of the grinding wheel to the rotational speed of the workpiece is adjusted to further minimize the workpiece roundness error by generating only precessing waves of minimum magnitude in the workpiece.