| 摘要 |
PURPOSE:To secure airtightness, by making the outer end face of a peripheral plate supporting the peripheral part of a blade into a stepped form and setting a partition plate to this stepped part so as to cause it to be located in a noncontact state with a desired minute void preserved. CONSTITUTION:When an impeller 1 is rotated, by operation of a rotary shaft 2, two different air streams are produced on both surfaces of the impeller 1 and the air sucked in separately from each of air-intake ports 5 and 6 flows side by side along groove parts on each of both surfaces of the blade 10 made of a corrugated thin plate, with a thin plate interposed in between. The outer end face of a peripheral plate 12 of the blade 10 is provided with a stepped part 13 with which a partition plate 4 is made up so as to engage in a noncontact state with a desired void preserved. With this superposed form of the partition plate 4 on the peripheral plate 12, the path of a clearance portion is lengthened whereby air flows with more difficult. |
