US Patent 7768168 Electric machine comprising a permanent magnet

The present invention relates to an electrical machine having a rotor, a stator, and a permanent magnet located on the rotor. The permanent magnet is embodied essentially as a hollow cylinder with axial and/or radial contact faces and is secured to the rotor at the axial and/or radial contact faces by means of retaining elements; the permanent magnet is elastically supported in the axial direction (X-X) and/or the radial direction of the rotor by means of the retaining elements.