CENTRIFUGAL FAN IMPELLER Russian patent published in 1994 - IPC

FIELD: manufacture of fans. SUBSTANCE: mounted between bearing and cover disks are blades. Each blade has profiled portion and hollow leading-edge flap which forms chamber and slots together with profiled portion. Swirlers are arranged in area of slots on profiled portion of blade and are made in form of bent plates whose concave side is directed to outlet of slot. Disks have through holes which are brought in communication with chamber and additional through holes located on center line of outlet section of slots on side of working and rear surfaces which are brought in communication with passages narrowing in the direction opposite to rotation of impeller. Each passage is formed by fixed wall and flexible plates whose one end is secured respectively on bearing and cover disks. Flexible plates are provided with motion mechanisms made in form of cam drive. Besides that, additional flexible plate is secured in chamber. Center section of this plate is movably secured on the profiled portion of blades and is provided with mechanism of cam drive. EFFECT: enhanced efficiency. 4 dwg