Electric machine comprising an improved slip ring, particularly for compressors and mills

The invention relates to an electric machine that comprises a stator (1), a rotor (2) rotatably mounted and arranged in said stator (1) and having electrical windings (3), a slip ring (4), and a cylinder-shaped element (5) that has a cylindrical diameter (6), said slip ring (4) being electrically connected to the electrical windings (3) and having a slip ring diameter (7), and said rotor (2) being radially arranged externally on the lateral surface of the cylinder-shaped element (5). The invention also relates to a compressor or a mill that comprises such an electric machine. In order to improve known electric machines comprising slip rings (4), it is suggested that the slip ring diameter (7) is smaller than the cylindrical diameter (6).