Abstract: A propeller blade includes an inner spar structure surrounding an inner spar foam core. Also included is a leading edge foam structure disposed proximate a leading edge of the inner spar structure. Further included is a trailing edge foam structure disposed proximate a trailing edge of the inner spar structure. Yet further included is an outer spar structure surrounding the inner spar structure, the leading edge foam structure and the trailing edge foam structure. Also included is a blade shell, a leading edge foam core located between the outer spar structure and the blade shell, and a trailing edge foam core located between the outer spar structure and the blade shell.

Abstract: A propeller blade assembly includes a spar extending along a propeller blade axis and an outer sleeve surrounding the spar portion at a root end of the rotor blade assembly. The spar is adhesively bonded to the outer sleeve at an interface portion. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. A method of assembling a propeller blade includes installing an outer sleeve over a spar at a root end of the spar, the spar a not fully cured composite component, and urging the spar into compressive conformance with the outer sleeve at an interface portion of the propeller blade assembly. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. The spar is cured thereby adhesively bonding the spar to the outer sleeve at the interface portion.

Abstract: A propeller blade includes a foam core, an adhesive layer formed on the core and a structural layer that covers at least a portion of the adhesive layer and that surrounds at least a portion of the foam core.

Abstract: According to one embodiment, a propeller blade includes a foam core and a structural layer formed of multiple layers that surrounds at least a portion of the foam core. The structural layer includes a mid-thickness location defined between the foam core and an outer edge of the structural layer and the multiple layers include at least one unidirectional layer and at least one biased layer disposed asymmetrically about the mid-thickness location.

Abstract: A propeller blade assembly includes a spar extending along a propeller blade axis and an outer sleeve surrounding the spar portion at a root end of the rotor blade assembly. The spar is adhesively bonded to the outer sleeve at an interface portion. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. A method of assembling a propeller blade includes installing an outer sleeve over a spar at a root end of the spar, the spar a not fully cured composite component, and urging the spar into compressive conformance with the outer sleeve at an interface portion of the propeller blade assembly. A spar maximum diameter along the interface portion is larger than an outer sleeve minimum diameter along the interface portion. The spar is cured thereby adhesively bonding the spar to the outer sleeve at the interface portion.

Abstract: A propeller blade includes a foam core and a structural layer that surrounds at least a portion of the foam core and includes a face side and a camber side is disclosed. The propeller blade also includes an insert disposed in the foam core in operable contact with the face side and the camber side of the structural layer.

Abstract: A propeller blade includes a foam core having a slot formed through it from a camber side to a face side, an internal stiffener disposed through the slot and including flanges in contact with both the camber and face sides and a structural layer that surrounds at least a portion of the foam core and in contact with the flanges on both the camber and face sides.

Abstract: A propeller blade includes a foam core formed of a combination of polyuria and polyvinyl chloride (pvc), an adhesive layer formed on the core and a structural layer that covers at least a portion of the adhesive layer and that surrounds at least a portion of the foam core.

Abstract: According to one embodiment, a propeller blade includes a carbon foam core and a structural layer that surrounds at least a portion of the carbon foam core.

Abstract: A propeller blade includes an inner spar structure surrounding an inner spar foam core. Also included is a leading edge foam structure disposed proximate a leading edge of the inner spar structure. Further included is a trailing edge foam structure disposed proximate a trailing edge of the inner spar structure. Yet further included is an outer spar structure surrounding the inner spar structure, the leading edge foam structure and the trailing edge foam structure. Also included is a blade shell, a leading edge foam core located between the outer spar structure and the blade shell, and a trailing edge foam core located between the outer spar structure and the blade shell.

Abstract: A retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an annular outer ring including a bearing race interface that is conical in shape and includes a radially inner surface that conforms to a radially outer surface of the annular loop; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop. Also, a propeller blade assembly includes a propeller blade having a blade portion and a root portion; and the retention assembly that is configured to attach to the propeller blade.

Abstract: A retention assembly for a propeller blade includes an inner ring that is conformally shaped to a bore of an annular loop, the annular loop being associated with a root portion of the propeller blade; a base that is configured to be immediately adjacent the annular loop; an outer ring that includes an extended tapered portion which decreases in radial thickness from an inboard end to an outboard end; and an adhesive that adhesively connects complementary surfaces of the outer ring and the annular loop. Also, a propeller blade assembly includes a propeller blade having a blade portion and a root portion and the retention assembly configured to be attached to the propeller blade.

Abstract: According to one embodiment, a propeller blade includes a carbon foam core and a structural layer that surrounds at least a portion of the carbon foam core.

Abstract: According to one embodiment, a propeller blade includes a foam core and a structural layer formed of multiple layers that surrounds at least a portion of the foam core. The structural layer includes a mid-thickness location defined between the foam core and an outer edge of the structural layer and the multiple layers include at least one unidirectional layer and at least one biased layer disposed asymmetrically about the mid-thickness location.

Abstract: According to one embodiment, a propeller blade includes a metallic foam core and a structural layer that surrounds at least a portion of the metallic foam core.

Abstract: A propeller blade includes a foam core having a slot formed through it from a camber side to a face side, an internal stiffener disposed through the slot and including flanges in contact with both the camber and face sides and a structural layer that surrounds at least a portion of the foam core and in contact with the flanges on both the camber and face sides.

Abstract: A propeller blade includes a foam core and a structural layer that surrounds at least a portion of the foam core and includes a face side and a camber side is disclosed. The propeller blade also includes an insert disposed in the foam core in operable contact with the face side and the camber side of the structural layer.

Abstract: A propeller blade includes a foam core, an adhesive layer formed on the core and a structural layer that covers at least a portion of the adhesive layer and that surrounds at least a portion of the foam core.

Abstract: A propeller blade for attachment to a receiving member of a hub of a propeller, is disclosed. The blade comprises a composite spar having an elongated portion formed in the shape of an airfoil. The elongated portion has a base end and a tip end, and a base portion for attachment to the receiving member. The base portion extends substantially transverse to the elongated portion and includes openings for receiving fasteners for fastening the spar to the receiving member. The blade also preferably includes an inner and outer sleeve for protecting the spar from frictional and compressive force wear in the base portion from fasteners. Preferably, the blade also includes an outer fiberglass shell and an inner weight tube for optionally adding more weight to the blade. The composite spar is preferably formed from a composite wall defining an interior space, which space is preferably filled with foam.

Abstract: A composite propeller blade and hub attachment assembly is disclosed. The assembly includes a blade root having a first connecting member and a hub arm having a second connecting member. The first connecting member meshingly engages the second connecting member. A device preloads the blade root and the hub arm. The first and second connecting members form a slot for receiving the preloading device. The preloading device includes an outer movable unit, an inner movable unit, and a mechanism for displacing the outer and inner movable units relative each other. As the mechanism for displacing relatively moves the inner and outer units, the preloading device is caused to expand and tension the blade root and hub arm for mechanically preloading the blade, in a manner which increases the low centrifugal load off lightweight composite blades.