| 摘要 |
PROBLEM TO BE SOLVED: To reduce an impact loss, caused by a fastening nut, of fluid flowing into an impeller.SOLUTION: An electric blower includes an impeller 12 held to a rotation shaft 2 by a fastening nut 33 and a screw part 33b and rotationally driven by a motor part 11. The impeller 12 includes: a front shroud 12a having an intake port; a rear shroud 12b; a plurality of blades 12c held between the pair of shrouds; a resin inducer 12d provided in a center portion of the impeller 12, having an approximately conical hub part 12f and a plurality of vanes around the hub part 12f, and straightening an intake air flow; and a cylindrical spacer 12e provided inside the hub part 12f. The fastening nut 33 has a curved surface smoothly continuing in a fastening head from the apex toward the motor part 11 and has a structure in which a screw hole does not penetrate to the apex, thereby reducing an inlet impact loss caused by turbulence in inflowing and a loss caused by leak from an impeller back face portion. This improves efficiency of the electric blower. |
