US 11,702,198 B2
Rotor for a hover-capable aircraft
Dario Bonanno, Samarate (IT); Phil Woody, Samarate (IT); Alexandros Stefanakis, Samarate (IT); and Vita Imperiale, Samarate (IT)
Assigned to LEONARDO S.P.A., Rome (IT)
Appl. No. 17/295,974
Filed by LEONARDO S.P.A., Rome (IT)
PCT Filed Sep. 30, 2019, PCT No. PCT/IB2019/058291
§ 371(c)(1), (2) Date May 21, 2021,
PCT Pub. No. WO2020/109880, PCT Pub. Date Jun. 4, 2020.
Claims priority of application No. 8209448 (EP), filed on Nov. 30, 2018.
Prior Publication US 2022/0009624 A1, Jan. 13, 2022
Int. Cl. B64C 27/473 (2006.01)
CPC B64C 27/473 (2013.01) [B64C 2027/4736 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A rotor (3, 5) for a hover-capable aircraft (1), comprising:
a hub (6, 8); and
a plurality of blades (7, 14) hinged on said hub (6, 8);
each said blade (7, 14) extending along an axis (B) and, in turn, comprising:
a leading edge (20) and a trailing edge (21), opposite to each other;
a top surface (22) and a bottom surface (23), opposite to each other and extending between said leading edge (20) and said trailing edge (21);
a chord (15) joining the points of said leading edge (20) and said trailing edge (21) in a section (S) of said blade (7, 14) orthogonal to said axis (B); and
a closed shell (30) made of composite material and adapted to withstand the torque directed along said axis (B) of said blade (7, 14);
said shell (30) comprising:
a first and a second element (31, 32), separate from each other, delimiting the respective said shell (30) on mutually opposite sides and respectively arranged at said top surface (22) and said bottom surface (23) of the respective said blade (7, 14); said first and second elements (31, 32) of each said blade (7,14) comprising respective first ends (37, 38) arranged on the side of the associated leading edge (20) and spaced apart from each other;
a first connection element (34) arranged on the side of the associated leading edge (20) and interposed between said first ends (37, 38) of the respective first and second elements (31, 32); and
a third element (80) connected to the associated said first and second elements (31, 32) and arranged on the side of the leading edge (20);
said first connection element (34) being connected to respective first faces (100) of said first and second elements (31,32);
said first faces (100) being respectively arranged on the opposite side of said top surface (22) and on the opposite side of said bottom surface (23) of said blade (7);
said blade (7,14) further comprising a fourth element (70) interposed between said third element (80) and said first connection element (34);
characterized in that said third element (80) is connected to respective second faces (101) opposite to corresponding said first faces (100) of said first and second elements (31, 32);
said first and second elements (31, 32) of each said blade (7, 14) respectively having, at least in part, a lie substantially parallel to a lie of the corresponding said top surface (22) and bottom surface (23) of the blade (7, 14);
said first and second elements (31, 32) of each said blade (7, 14) having a thickness in the transverse direction to the lie of the respective said top surface (22) and bottom surface (23);
said first and second elements (31, 32) respectively comprising a first and a second portion (36) opposite to each other and having greater thickness than respective remaining parts (35) of the respective said second and third elements (31, 32);
an extension (L) of said first and second portions (36) parallel to said chord (15) in said section (S) ranging between 30% and 35% of a length (M) of said chord (15) in said section (S).