Curved blade, preparation method thereof, and centrifugal impeller comprising the same

A method for preparing a curved blade of a centrifugal impeller, the centrifugal impeller comprising a disk and a cover, wherein the centrifugal impeller is centered around a rotating axis, the disk comprises a disk surface perpendicular to the rotating axis, and the cover comprises a cover surface perpendicular to the rotating axis;

• the method comprising:
• S1) providing a primary blade, wherein the primary blade comprises an inlet edge, an outlet edge, a blade root, and a blade top;
• the inlet edge is disposed oppositely to the outlet edge;
• the blade root is disposed oppositely to the blade top;
• the blade root is adapted to be disposed along and connected to the disk surface, the blade top is adapted to disposed along and connected to the cover surface;
• the inlet edge and the outlet edge are disposed between the blade root and the blade top;
• the inlet edge is adapted to be disposed adjacent to the rotating axis with respect to the outlet edge;
• and a vertex is defined at a joint of the outlet edge and the blade top;
• S2) forming a fold line on the primary blade, wherein the fold line comprises a first point and a second point;
• the first point is defined on the outlet edge;
• the second point is defined on the blade top;
• a first curve is formed on the outlet edge between the first point and the vertex;
• a second curve is formed on the blade top between the second point and the vertex;
• the first curve, the second curve, and the fold line enclose a bending region;
• and
• S3) bending the bending region along the fold line towards the rotating axis to form the curved blade, while moving the second curve of the bending region along the cover surface.