摘要 |
An improved startup device for the rotor of a permanent-magnet synchronous motor, particularly adapted for liquid conveyance pumps, such as those used in electrical household appliances or the like, which are equipped with a permanent-magnet synchronous motor of the type comprising a stator unit (11) with a pack of metal laminations and electrical windings (12) supported by a body (13) that forms a substantially cylindrical chamber (14) that accommodates, upon assembly, the rotor unit (23), which is axially crossed by a motor shaft (19). The rotor unit (11) comprises a cup-shaped cylindrical element (24) that is closed hermetically by means of a lid (25) and is rigidly coupled to the shaft (19) either directly or by means of the lid (25); the permanent-magnet rotor (29) is rotatably accommodated inside the cup-shaped element (24) and rotates freely with respect to the shaft (19); motion transmission teeth (31) are provided between the rotor (12) and the shaft (19) and are adapted to cause the rotation of the shaft after the rotor, activated by the stator (12), has turned without a load through a given rotation angle. <IMAGE> |