HELICOPTER ENCLOSED ANTITORQUE PROPELLER Russian patent published in 2015 - IPC B64C27/82 

FIELD: aircraft engineering.

SUBSTANCE: this antitorque rotor has shaped leading part, cylindrical part and trailing part. It consists of stator accommodating reduction gear with input and output shafts whereat the hub with vanes secured thereto is mounted. Fixed directing vanes are fitted inclined to the surface of encasement and are secured by one end to encasement cylindrical part and by other end at stator. Antitorque rotor comprises twelve blades arranged in two lines. Second line of blades is located in encasement cylindrical part. Spacing between said lines makes 0.08-0.20 of rotor radius. Note here that angular distances between two adjacent blades in common sequence for two lines of blades in each of three consecutive pairs of blades are related as 3:5:7. Note also that the number of blades in every line is even and that said blades are located diametrically opposite. Supports of directing vanes at encasement cylindrical surface are arranged in symmetry relative to input shaft axis. Attachment of every blade to stator is shifted relative to this blade to encasement surface in clockwise direction on the side of shaped inlet part of said encasement.

EFFECT: decreased acoustic radiation of rotor at minimum vibration, better aerodynamics.

4 dwg