Synchronous machine and a process of manufacturing a synchronous machine

A synchronous machine comprising a stator and a rotor (10), a substantially cylindrical rotor (10) having a surface portion and a rotor nucleus portion (12), the rotor (10) being provided with a cage (16) positioned at the surface portion, the cage (16) being formed by conductive bars allocated in cage grooves (16) and rings (18), which interconnect the bars at their end,

• the rotor (10) further comprising at least one pair of permanent magnets (22), the permanent magnets (22) being allocated in magnet-fixation grooves (20), the magnet-fixation grooves (20) being positioned longitudinally on the nucleus (12) of the rotor (10),
• the fixation groove (20) comprising a substantially rectangular section having an engagement region (RE) and a first free-end portion (25) and a second free-end portion (26), the fixation groove (20) extending along the rotor (10), the permanent magnet (22) being fixedly associated to the rotor (10) in the engagement region (RE), the fixation groove (20) being positioned in a secant manner with respect to the surface portion of the rotor (10), the fixation groove (20) having a first elongated end (101) configured so as to create a reluctance-increase channel (50) close to the first free-end portion (25), the elongated end (101) extending from the first free-end portion (25) to a region adjacent the end of the groove bottom (15′), the first elongated end (101) being configured from an opening in the rotor (10), the opening extending along the rotor (10) and along the fixation groove (20), the magnet-fixation grooves (20) having displacement limiters (200, 201) adjacent the first free-end portion (25) and the second free-end portion (26), the displacement limiters being formed by nucleus (12) portions that extend inside the fixation grooves (20) in a direction parallel to the magnet width (23).