Monodirectional impeller with flexible vanes

A monodirectional impeller for centrifugal electric pumps having a permanent-magnet synchronous motor, comprising:

• a first disk-like element, which is monolithically provided with curved nondeformable vanes;
• an annular element, whose dimensions are contained within inlet dimensions of said nondeformable vanes, said annular element being provided with means for coupling to said first disk-like element, said annular element having flexibly deformable vanes which cantilever outward and are interposed between the nondeformable vanes, said deformable vanes being adapted to modify, when loaded, their curvature in both directions of rotation, so that the power required for rotation in only one of the two directions is greater than a maximum power that the motor can deliver;
• and
• a second disk-like element rigidly coupled to said nondeformable vanes;
• wherein said first disk-like element and said second disk-like element enclose said deformable and non-deformable vanes, and leave the flexibly deformable vanes free.