Patent ID: 8408873

Claim:
A welding slot sealing structure for an impeller having a round disk, a plurality of blades attached radially at a predetermined angle to a surface of the disk, and a shroud attached to outer edges of the blades, in which slots are formed in a surface of the shroud, the blades are brought into contact with an opposite surface of the shroud from the slots and the shroud and the blades are welded by applying a laser beam from surfaces of the slots, wherein after the blades have been laser-welded to the shroud, components different from the shroud are installed on the surfaces of the slots on the opposite side from the blades so that the slots are flush with the shroud, wherein after the blades and the shroud have been laser-welded, the slots are filled part way, and the slots are sealed with the components different from the shroud on the surfaces of the slots, and wherein the components different from the shroud comprise overlays and lids, the slots are filled part way with the overlays, and the lids cover the slots.