A rotor assembly for a rotorcraft, comprising a rotor shaft, a torque transmission unit that is non-rotatably mounted to the rotor shaft, a rotor hub that is rotatably mounted to the rotor shaft via an associated angular displacement enabling component, and at least two rotor blades that are connected to the rotor hub, wherein the torque transmission unit is coupled to the at least two rotor blades on a rotor assembly outflow side via a pitch control unit, wherein the pitch control unit transmits to the at least two rotor blades torque that is applied from the rotor shaft to the torque transmission unit, and wherein the pitch control unit increases a respective pitch angle of the at least two rotor blades if the torque is increased.

A rotor assembly comprises a rotor hub and rotor-blade assemblies. The rotor hub comprises rotor-blade supports. Each rotor-blade assembly is coupled to a respective one of the rotor-blade supports and comprises a flap axle, a hub connector, a rotor blade, and a torsion strap. The flap axle extends through a respective one of the rotor-blade supports and has a central flap-axle axis. The hub connector is pivotable relative to a rotor-blade support about the central flap-axle axis and defines a central hub-connector axis. The rotor blade is coupled to and is pivotable relative to the hub connector, and, together with the hub connector, is pivotable relative to a respective one of the rotor-blade supports about the central flap-axle axis. The torsion strap has a first end, coupled to the rotor blade, and a second end, through which the flap axle passes.

A rotor blade retention assembly is configured to connect a rotor blade to a central hub comprising a hub arm coupled to and extending radially outward from a hub bowl. The hub arm includes a hub arm lug. The rotor blade retention assembly includes a tension-torsion strap with an inboard end and an outboard end, the inboard end including an inboard pin hole and the outboard end including an outboard pin hole. The rotor blade retention assembly further includes an inboard blade pin and an outboard blade pin. The inboard blade pin is configured to extend through the hub arm lug and the inboard pin hole and to couple the inboard end of the tension-torsion strap to the hub arm. The outboard blade pin is configured to extend through a blade lug of a rotor blade and the outboard pin hole and to couple the outboard end of the tension-torsion strap to the rotor blade.

A rotor system includes a drive hub, a set of rotor blades extending radially from the drive hub, and a set of tension-torsion straps connecting the rotor blades to the drive hub. The drive hub has a rotor mast opening extending along a mast axis. The rotor system is configured to rotate about the mast axis. The drive hub further has a set of mounting slots for mounting the tension-torsion straps. The mounting slots are arranged along a circle around the drive hub, each mounting slot extending through the drive hub along a respective mounting axis. The mounting axis of each of the mounting slots is biased relative to the mast axis. The tension-torsion straps are mounted to the drive hub at their corresponding mounting slots.

A rotary wing aircraft includes an airframe, a stationary mast fixedly engaged to the airframe and extending along a first axis, and an electric motor. The electric motor includes a stator assembly engaged to the mast and a rotor assembly disposed radially outward from the stator assembly and configured to rotate with respect to the stator assembly. A plurality of rotor blades project radially outward from the rotor assembly.

A rotary wing aircraft includes an airframe, a stationary mast fixedly engaged to the airframe and extending along a first axis, and an electric motor. The electric motor includes a stator assembly engaged to the mast and a rotor assembly disposed radially outward from the stator assembly and configured to rotate with respect to the stator assembly. A plurality of rotor blades project radially outward from the rotor assembly.

A structural member for use in a rotor system which rotates about a rotational axis includes a pin which extends substantially perpendicular to the rotational axis, a filler component positioned adjacent the pin, and a plurality of layers of composite material having fibers oriented lengthwise along a central axis which is perpendicular to the rotational axis. The plurality of fibers in the layers of composite material is wrapped about the pin and the filler component such that the fibers extend along the central axis and the plurality of layers form an opening filled by the filler component and which decreases as a function of distance from the pin along the central axis.

A structural member for use in a rotor system which rotates about a rotational axis includes a pin which extends substantially perpendicular to the rotational axis, a filler component positioned adjacent the pin, and a plurality of layers of composite material having fibers oriented lengthwise along a central axis which is perpendicular to the rotational axis. The plurality of fibers in the layers of composite material is wrapped about the pin and the filler component such that the fibers extend along the central axis and the plurality of layers form an opening filled by the filler component and which decreases as a function of distance from the pin along the central axis.

A rotor blade for a rotary wing aircraft includes a rotor hub including a first flex-beam attachment member and a flex-beam assembly. The flex-beam assembly includes a flex-beam support member having an attachment end and a wrapping end. A first flex-beam includes a first end, a second end and an intermediate portion. The first end of the first flex-beam is connected at the first flex-beam attachment member and the second end of the first flex-beam being connected to the attachment end of the flex-beam support member. A second flex-beam includes first end portion, a second end portion and an intermediate section. The first end portion of the second flex-beam is connected at the first flex-beam attachment member, the second end portion of the second flex-beam being connected at the second flex-beam attachment member and the intermediate section extending about the wrapping end of the flex-beam support member.

A rotor blade for a rotary wing aircraft includes a rotor hub including a first flex-beam attachment member and a flex-beam assembly. The flex-beam assembly includes a flex-beam support member having an attachment end and a wrapping end. A first flex-beam includes a first end, a second end and an intermediate portion. The first end of the first flex-beam is connected at the first flex-beam attachment member and the second end of the first flex-beam being connected to the attachment end of the flex-beam support member. A second flex-beam includes first end portion, a second end portion and an intermediate section. The first end portion of the second flex-beam is connected at the first flex-beam attachment member, the second end portion of the second flex-beam being connected at the second flex-beam attachment member and the intermediate section extending about the wrapping end of the flex-beam support member.