| 摘要 |
PURPOSE:To prevent reduction of pressure certainly, and maintain blowing-out pressure at a high value by providing respective side end parts of the air suction port and the blowing-out port of an inside guide case in close proximity to an impeller, and forming a path between both ends in a circularly recessed shape so as to increase the interval thereto from the impeller. CONSTITUTION:Air sucked from an air suction port 40 into an impeller 10 flows to an air blowing-out port 50 a circular shaped air flow A, and a part of the air flow becomes a vortex B which flows around a center axis (y) located eccentrically toward the inner side from the center axis (x) of the impeller 10. If the shape and a clearance 60 at the intermediate part 33 of an inner guide case 30, are formed in a circular recessed shape and a volume which can accept the vortex B coming out of the impeller 10, an overhang flow of the vortex B from the impeller 10 can be stored inside the space 60 so as to form an independent system of a closed loop. An overhang flow into the clearance 60 by the vortex B acts as a wall opposing to air flow running backward to the suction port 40 side through the clearance 60 from the blowing out port 50 side so as to prevent invasion of the air flow. Since, the air suction side end part 31 of air 30 approaches the impeller 10, it is possible to prevent separation into the clearance 60, of an overhung vortex B on the suction port 40 side. |
