An electric motor comprises a stator (1, 5, 8) having an air-gap which extends around an axis and in which a rotating magnetic field is generated, and a rotor (11, 12, 13) comprising a shaft (11) which is rotatably held by a bearing (10) and a permanent magnet (13) which is held in said air-gap and is driven to rotate around said axis by said rotating magnetic field. The stator (1, 5, 8) is adapted to generate, in addition to said rotating magnetic field, a stationary magnetic field which is rotationally asymmetric with respect to said axis.
