Abstract: A grinding machine comprises a grinding spindle which can be displaced in a horizontal plane relative to a workpiece. The grinding spindle drives a grinding wheel, which is mounted for rotary movement about a horizontal axis, and is arranged on a swivel carriage arranged for rotary movement about a vertical axis relative to a base plate. A measuring device is provided for detecting the rotary position of the swivel carriage relative to the base plate comprise a first sensor element which is rigidly connected to the base plate and a second sensor element that can be rotated together with the swivel carriage. In order to simplify the measuring device and to make it easily accessible the sensor elements are arranged outside the said swivel carriage and the second sensor element is connected to the swivel carriage via a power transmission.

Abstract: A grinding wheel comprises a disk-shaped body (12) which is equipped with a peripheral processing surface consisting of a grinding material. There is further provided an at least two-part flange (20, 21) retaining the body (12) on both sides thereof and provided with a mounting opening (22) for a holding arbor of a grinding machine. In order to achieve a centering effect between the body and the flange, with the simplest possible constructional means, a first flange part (20) is provided with a circumferential surface (34) whose cross-section, taken along a radial plane, exhibits the shape of an n-cornered polygon. The body (12) is in contact with the circumferential surface (34) via bolts (32) projecting radially inwardly. The number of bolts (32) corresponds to the number of the corners of the polygon. The bolts (32) can be rotated relative to the circumferential surface (34) in the circumferential direction.