Abstract: An impeller (1) of a fluid pump according to the present invention comprises: an impeller body (10) having a first shroud (20) and a plurality of vanes (30) provided on the first shroud (20); and a second shroud (50) bonded to the impeller body (10) and arranged opposed to the first shroud (20) in a central axis direction across the plurality of vanes (30). The first shroud (20) has a boss part (40) protruding in the central axis direction. The second shroud (50) has a central hole (53) through which the boss part (40) is inserted in the central axis direction. By a combination of a recessed first groove part (41) formed on an outer circumferential surface of the boss part (40) and a recessed second groove part (54) formed on an inner circumferential surface of the central hole (53), a balance hole (B) penetrating in the central axis direction is constituted.

Abstract: An impeller (1) of a fluid pump according to the present invention comprises: an impeller body (10) having a first shroud (20) and a plurality of vanes (30) provided on the first shroud (20); and a second shroud (50) bonded to the impeller body (10) and arranged opposed to the first shroud (20) in a central axis direction across the plurality of vanes (30). The first shroud (20) has a boss part (40) protruding in the central axis direction. The second shroud (50) has a central hole (53) through which the boss part (40) is inserted in the central axis direction. By a combination of a recessed first groove part (41) formed on an outer circumferential surface of the boss part (40) and a recessed second groove part (54) formed on an inner circumferential surface of the central hole (53), a balance hole (B) penetrating in the central axis direction is constituted.

Abstract: An impeller (100) for a fluid pump according to the present invention comprises a shroud (150) that has a disk shape and is drivingly rotated about a center axis, and a cover (110) comprising a cover main body (120) having a truncated cone shape with an inlet port (123) for a fluid formed at a center and a plurality of blades (130) arranged around a center axis of the cover main body (120). The cover (110) and the shroud (150) are joined to each other with a welding contacting portion (135) and a welding contacted portion (177) welded to each other in a center axis direction, in a state where another end surface of the shroud (150) and a distal end portion (131) of the blades (130) are in parallel with each other.