shows cross sections a a u2032 b b u2032 c c u2032 taken at three points along the rotor slot 2 u2032 in a central region as indicated by the cross section a a u2032 the intermediate plate 33 is simply a flat plate at the hub side 13 of the rotor 1 u2032 the rotor slot 2 u2032 is offset and therefore slightly tilted the intermediate plate 33 b for the magnet assembly 3 arranged in this section of the rotor slot 2 u2032 is wedge shaped to compensate for the tilted rotor slot floor at the brake disk side 12 of the rotor 1 u2032 the rotor slot 2 u2032 is offset in the opposite direction and therefore slightly tilted also in the opposite direction the intermediate plate 33 c for the magnet assembly 3 arranged in this section of the rotor slot 2 u2032 has a mirror image wedge shape to compensate for the changing inclination of the rotor slot floor for both wedge shaped intermediate plates 33 b 33 c the u2018 shorter u2019 side can be as thick as the uniform intermediate plate 33 used in the central region of the slot 2 u2032 while the u2018 higher u2019 side can be slightly higher for example 0 9 mm higher than the uniform intermediate plate 33 these thicknesses are shown in an exaggerated manner here to clearly illustrate the differences between the various intermediate plates 33 33 b 33 c using such wedge shaped plates 33 b 33 c the magnet pole pieces 31 lie essentially in the plane of the rotor inner surface.