AXIAL-FLOW FAN Russian patent published in 2003 - IPC

FIELD: mechanical engineering. SUBSTANCE: axial-flow fan 1 has central hub 3 and blades 4; each blade has root 5 and tip 6 and is bounded by convex edge 7 whose projection on plane of rotation of fan is defined by parabolic segment and concave edge 8 whose projection on plane of rotation of fan is defined by arc of circle. Blade 4 has sections with aerodynamic profiles 18 and surface 18a including at least one rectilinear section (t) and blade angle (β) which gradually and continuously reduces from blade root 5 to tip 6 of blade 4 according to cube root law as function of fan radius. EFFECT: higher efficiency. 11 cl, 8 dwg, 1 tbl