US 11,787,533 B2
Rotor assemblies for rotorcraft
Dennis K. Kennedy, Mesa, AZ (US); Joshua Jeffrey Bracken, Gilbert, AZ (US); and Jeffrey L. Sorensen, Fountain Hills, AZ (US)
Assigned to The Boeing Company, Arlington, VA (US)
Filed by The Boeing Company, Chicago, IL (US)
Filed on May 20, 2021, as Appl. No. 17/326,222.
Claims priority of provisional application 63/112,446, filed on Nov. 11, 2020.
Prior Publication US 2022/0144418 A1, May 12, 2022
Int. Cl. B64C 27/39 (2006.01); B64C 27/35 (2006.01); B64C 27/48 (2006.01)
CPC B64C 27/39 (2013.01) [B64C 27/35 (2013.01); B64C 27/48 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A rotor assembly for a rotorcraft, the rotor assembly comprising:
a rotor hub, comprising rotor-blade supports; and
rotor-blade assemblies, each coupled to a respective one of the rotor-blade supports;
wherein:
the rotor hub has a rotation axis about which the rotor hub has a rotational symmetry of order N;
the rotor-blade supports are N in number; and
each of the rotor-blade assemblies comprises:
a flap axle, extending through the respective one of the rotor-blade supports and having a central flap-axle axis;
a hub connector, coupled to the respective one of the rotor-blade supports via the flap axle, pivotable relative to the respective one of the rotor-blade supports about the central flap-axle axis, and defining a central hub-connector axis that is perpendicular to the central flap-axle axis;
a rotor blade, coupled to the hub connector, pivotable relative to the hub connector about the central hub-connector axis, and, together with the hub connector, pivotable relative to the respective one of the rotor-blade supports about the central flap-axle axis; and
a torsion strap extending along the central hub-connector axis, having a first end, coupled to the rotor blade, and a second end, through which the flap axle passes.