An apparatus comprising a rotor yoke comprising two longitudinal side portions interconnected by two outboard portions, wherein a center portion of each longitudinal side portion comprises a build-up of material that is configured to accommodate a yoke hub clamp. Included is an apparatus comprising a rotor yoke comprising two longitudinal side portions interconnected by two outboard portions, wherein no apertures pass through the two longitudinal side portions and the two outboard portions. Also included is a method of coupling aircraft blades comprising providing a rotor yoke comprising two longitudinal side portions interconnected by two outboard portions, wherein no apertures pass through the two longitudinal side portions and the two outboard portions.

A bearing sleeve assembly includes a rigid inner element having a cylindrical inner diameter bore and an outer surface that is non-cylindrical. Also included is a rigid outer element spaced radially outwardly from the rigid inner element, the rigid outer element comprising a cylindrical member with a uniform cross-section that forms a ring with an inner-diameter surface and an outer-diameter surface, the outer element's inner-diameter surface and the non-cylindrical outer surface of the inner element defining a non-uniform annulus therebetween. Further included is an elastomeric core disposed between the rigid inner element and the rigid outer element within the non-uniform annulus, the elastomeric core having a first thickness at a first location and a second thickness at a second location, the first thickness being greater than the second thickness.

A bearing sleeve assembly includes a rigid inner element having a cylindrical inner diameter bore and an outer surface that is non-cylindrical. Also included is a rigid outer element spaced radially outwardly from the rigid inner element, the rigid outer element comprising a cylindrical member with a uniform cross-section that forms a ring with an inner-diameter surface and an outer-diameter surface, the outer element's inner-diameter surface and the non-cylindrical outer surface of the inner element defining a non-uniform annulus therebetween. Further included is an elastomeric core disposed between the rigid inner element and the rigid outer element within the non-uniform annulus, the elastomeric core having a first thickness at a first location and a second thickness at a second location, the first thickness being greater than the second thickness.

A bearing arrangement with a first bearing layer comprising a first bearing support element and a second bearing layer comprising a second bearing support element, the first and second bearing layers being glidingly interconnected by at least one intermediate gliding element, wherein at least one first gliding surface is arranged between the first bearing support element and the at least one intermediate gliding element, and wherein at least one second gliding surface is arranged between the second bearing support member and the at least one intermediate gliding element, the at least one intermediate gliding element being elastically attached to the first bearing support element by means of at least one first flexible connector and to the second bearing support element by means of at least one second flexible connector.

A bearing arrangement with a first bearing layer comprising a first bearing support element and a second bearing layer comprising a second bearing support element, the first and second bearing layers being glidingly interconnected by at least one intermediate gliding element, wherein at least one first gliding surface is arranged between the first bearing support element and the at least one intermediate gliding element, and wherein at least one second gliding surface is arranged between the second bearing support member and the at least one intermediate gliding element, the at least one intermediate gliding element being elastically attached to the first bearing support element by means of at least one first flexible connector and to the second bearing support element by means of at least one second flexible connector.

A rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

A rotor hub assembly for a rotorcraft includes a yoke forming a bearing bore. The yoke has a teetering axis extending through the bearing bore. The rotor hub assembly includes a flapping bearing disposed in the bearing bore. The flapping bearing is operable to regulate teetering of the yoke about the teetering axis. The rotor hub assembly includes an axial spring abutting the flapping, thereby reducing movement of the flapping bearing along the teetering axis.

A rotor blade retention assembly includes a central hub, a rotor blade including an upper outer surface, a lower outer surface, a blade hole, and a proximal end coupled to the central hub, a strap member extending along a portion of the rotor blade such that a distal end receiving portion extends into the blade hole, and a retainer assembly disposed within the blade hole and coupled to the strap member. The retainer assembly includes an upper bushing and a lower bushing slidably disposed within the blade hole. The upper bushing includes a counterbored portion. The retainer assembly also includes an outboard blade pin disposed within the distal end receiving portion and includes a blade pin inner cavity.

A rotor blade retention assembly includes a central hub, a rotor blade including an upper outer surface, a lower outer surface, a blade hole, and a proximal end coupled to the central hub, a strap member extending along a portion of the rotor blade such that a distal end receiving portion extends into the blade hole, and a retainer assembly disposed within the blade hole and coupled to the strap member. The retainer assembly includes an upper bushing and a lower bushing slidably disposed within the blade hole. The upper bushing includes a counterbored portion. The retainer assembly also includes an outboard blade pin disposed within the distal end receiving portion and includes a blade pin inner cavity.

A rotor hub assembly for a rotary-winged aircraft includes a spool portion and a plurality of hub arms extending radially outwardly from the spool portion. A rotor blade is connectable to each hub arm. Each hub arm includes a spine portion and at least two leg portions extending from the spine portion. The spine portion and the at least two leg portions defining an I-shaped cross-section of each hub arm. A rotor assembly includes a rotor hub assembly including a spool portion and a plurality of hub arms extending radially outwardly from the spool portion. Each hub arm includes a spine portion and at least two leg portions extending from the spine portion. The spine portion and the at least two leg portions define an I-shaped cross-section of each hub arm. A rotor blade is secured to each hub arm.