Permanent-magnet rotor for a synchronous motor particularly for a washing machine pump for industrial and domestic use and the like

A synchronous motor, particularly for a pump of a washing machine for industrial and domestic use and the like, comprising:

• an external stator;
• and
• an internal permanent-magnet rotor to be immersed in a fluid, said internal permanent-magnet rotor comprising:
• a cup-like body, formed of a plastic material, comprising a base end, an open end, a side wall, and a plurality of longitudinal recesses on an outer side of said side wall, said longitudinal recesses extending from the base end to the open end of the cup-like body and definining between each other a plurality of positioning seats on the inner side of said side wall;
• a central cylindrical core comprising an axis X-X and an axial passage, said central cylindrical core being placed within the cup-like body;
• and
• a plurality of permanent magnets surrounding the central cylindrical core and having an extrados and an intrados and side edges, said permanent magnets being placed between the side-wall of the cup-like body and the central cylindrical core with the extrados facing the cup-like body, and being housed within the positioning seats of the cup-like body;
• wherein the core, the magnets and the cup-like body are incorporated in a substantially cage-like shaped structure formed of plastic material and having opposite bottoms and columns extended between the opposite bottoms,
• wherein said opposite bottoms of the cage-like structure abut the ends of the cup-like body in such a way as to sealingly enclose between them the central cylindrical core and the permanent magnets, and
• wherein said columns of the cage-like structure are housed in the recesses and are counter-shaped to them, in such a way as to define, alone with the side wall of the cup-like body, a cylindrical outer surface of the rotor of the cup-like body.