HELICOPTER WITH CROSSWISE DUCT Russian patent published in 2015 - IPC B64C27/82 B64C27/04 

FIELD: transport.

SUBSTANCE: helicopter comprises tail section (1) with crosswise duct (6) and drive shaft (23) inside driven shaft cowl (14) to counteract the torque. Device (2) comprises rotor and stator shifted in rotor axis, drive shaft (23) and control rod (24) to control the pitch of blades (13). Rotor comprises sleeve (12) and vanes (13). Rotor vanes (13) feature modulated angular distribution around said rotor axis. Stator comprises multiple vanes (16, 17). Said vanes (16, 17) are modulated in angle to limit the interference between rotor vanes (13) and stator vanes (16, 17). This is ensured by making whatever angular difference between two rotor vanes (13) comply with whatever angular difference between two stator vanes (16, 17) or whatever stator vane and drive shaft cowl (14). Rotor runs about axis inclined through -20° to +45° from axis (18) shifted in parallel relative to helicopter or drive shaft lengthwise axis. Maximized spacing for any points (21) on trailing edges (30) of stator vanes (16, 17) is defined by the width of case (3), that is, confined inside the contour composed by said case (3).

EFFECT: decreased noise.

15 cl, 6 dwg