Patent ID: 7923882

Claim:
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 (R E ) 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 (R E ), 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 ).