Abstract: A numerically controlled grinding machine for grinding workpieces, such as tools, and other metallic or ceramic elements, comprises a machine bed (1) having fixedly connected to it a rigid, distortion-free portal (9) which has a reinforcing rear wall (13) rigidly connected to the machine bed, two side stands (10) and a horizontal bridge (11) which extends at a distance above the machine bed (1). A double wheel grinding spindle carrier (20) is adjustably mounted on the portal (9) for positioning along at least one axis (-y). The machine bed (1) projects at one side from the portal (9). The machine bed (1) supports a workpiece carrier movable about a plurality of axes.

Abstract: A clamping device is mounted to the machine bed of a grinding machine and is longitudinally slideable along said machine bed. Adjacent to the machine bed a rotatably driven grinding wheel is arranged such that by means of several actuators relative movements are possible between workpiece and tool in an X-Y-Z coordinate system related to the workpiece, while the grinding wheel is slideable parallel to its rotational axis which is adjusted according to the pivoting angle. To achieve a smooth transition without a ridge between the shaft portion and the hemispherical portion of the workpiece, the grinding wheel is moved, without interrupting its path curve such that the rotational axis describes roughly the arc of a circle about the hemispheric end. Simultaneously the grinding wheel performs a translatory movement parallel to its rotational axis such that the cutting edge in the hemispherical portion runs at a positive rake in the direction of the longitudinal axis of the workpiece.