Process For Mounting Magnets in an Electric Motor Rotor and Electric Motor Rotor

A process for mounting magnets in an electric motor rotor, said rotor comprising:

• a lamination stack (10) provided with a central axial bore (11);
• a plurality of axial channels (12) disposed around the central axial bore (11);
• and axial bores (13) disposed in a peripheral portion of the lamination stack (10) and which are external to the axial channels (12);
• permanent magnets (20) housed in the axial channels (12) so as to define the rotor poles;
• and
• a rotor cage (30) formed by a pair of end rings (31), each seated against an adjacent end lamination of the lamination stack (10) and interconnected by a plurality of bars (32) which are cast in the axial bores (13) in a single piece with the end rings (31), said process characterized in that it comprises the steps of:
• a—forming an end ring (31) with at least one inner radial projection (33) adjacent to each respective axial channel (12), said inner radial-projection (33) being disposed radially external to the projection of the contour of said axial channel (12);
• b—mounting in each axial channel (12) at least one respective permanent magnet (20);
• and
• c—deforming each inner radial projection (33) in order to increase its radial extension the sufficient to radially cover at least part of the projection of the contour of said axial channel (12), defining a stop for axially retaining the respective permanent magnet (20).