Patent ID: 7033145

Claim:
A centrifugal pump, for electrical household appliances, comprising: a support casing including a body and a volute which are coupled to one another to define a working chamber, a synchronous electrical motor driven by alternating current, having a stator which is stationary relative to the body, and having a permanent magnet rotor which is rotatable in the body, and a bladed impeller mounted rotatably in the working chamber and provided with a hub which has a cavity; the impeller being coupled to an end of the rotor which extends into the cavity of the hub of the impeller; wherein said end of the rotor and the hub of the impeller are provided with a first and a second transverse coupling formation, respectively, which have respective angular extensions which are predetermined in such a manner that there is angular play, suitable for promoting the starting of the motor, between the rotor and the impeller; the coupling formations being capable of interfering with one another, after the motor has started, in order to bring about the drive of the impeller by the rotor; wherein the portions of the coupling formation of the rotor that are to cooperate with the coupling formation of the impeller are produced from a resilient material; and wherein the coupling formation of the rotor comprises: a substantially radial transverse appendage which extends from and is integral with a drive body of substantially rigid material which is secured to the rotor, and a damping formation which is molded in a single piece of resilient material onto the drive body and has two end portions which are molded onto the opposite surfaces or faces of the appendage and which are to engage the coupling formation of the impeller, and an intermediate connecting and retaining portion which interconnects the end portions and extends at least partially through the drive body in such a manner that the damping formation as a whole is constrained in a stable manner, axially and angularly, on the drive body.