A system includes a first structure having an upper surface coupled to a second structure by a fastener assembly including a bushing positioned within an opening in the upper surface of the first structure. An inner opening of the bushing defines an inner diameter, and a fastener is at least partially positioned within the bushing. An outer surface of the fastener defines an outer diameter of the fastener. The bushing and the fastener are configured such that a space between the outer surface of the fastener and the inner opening of the bushing defines a gap which increases in size in a direction extending from the upper surface to the lower surface of the first structure.

A system includes a first structure having an upper surface coupled to a second structure by a fastener assembly including a bushing positioned within an opening in the upper surface of the first structure. An inner opening of the bushing defines an inner diameter, and a fastener is at least partially positioned within the bushing. An outer surface of the fastener defines an outer diameter of the fastener. The bushing and the fastener are configured such that a space between the outer surface of the fastener and the inner opening of the bushing defines a gap which increases in size in a direction extending from the upper surface to the lower surface of the first structure.

A propeller provided with interchangeable blades, and to a method of mounting such interchangeable blades on the propeller. The propeller comprises a hub, fastening fittings, rotation guide devices for guiding the fastening fittings in rotation relative to the hub, locking parts, and blades. The fastening fittings are configured to be assembled into the hub from the inside of the hub, and the locking parts lock respective ones of the fastening fittings onto the hub. The blades are fastened to respective ones of the fastening fittings outside the hub and can thus easily be replaced with other blades without removing the propeller.

A propeller attaching device includes a coupler that rotates integrally with an output shaft of a motor, a movable body, and a resilient body. The coupler allows attachment/detachment of an attachment portion of the motor by rotation of the propeller in the circumferential direction and restricts the movement of the propeller in an axial direction. The movable body includes a second receiving portion, and is supported by the coupler so as to be movable in the axial direction. The attachment/detachment position is a position where attachment/detachment of the attachment portion to/from the first receiving portion is allowed. The restriction position is positioned in a first direction relative to the attachment/detachment position, the first direction extending from the other end to one end of the output shaft in the axial direction of the output shaft, and restricts the rotation of the propeller in the circumferential direction relative to the base.

A rotor blade assembly connectable to a rotor hub configured to rotate about a center axis includes a torsional pitch member coupled to the rotor hub, a torque tube coupled to the torsional pitch member, wherein the torsional pitch member extends away from the center axis through a portion of the torque tube, a blade coupled to the torque tube, and a pitch control member coupled to the torque tube and configured to control a pitch angle of the blade, wherein the torsional pitch member includes a first curvilinear channel and a second curvilinear channel each having a front side and a back side, wherein the first curvilinear channel and the second curvilinear channel are disposed adjacent to each other, such that the back side of the first curvilinear channel faces the back side of the second curvilinear channel.

Compact thrust bearing assemblies, mechanical assemblies including the compact thrust bearing assemblies, and methods of providing limited rotational motion in a compact thrust bearing assembly are disclosed herein. The thrust bearing assemblies include a plurality of rigid load-bearing structures arranged in a layered stack that defines a first end and an opposed second end. The thrust bearing assemblies further include a plurality of rotation-limiting structures configured to restrict relative rotation between adjacent pairs of rigid load-bearing structures. The thrust bearing assemblies also include a first load-receiving surface configured to receive a first thrust load and a second load-receiving surface configured to receive a second thrust load. The methods include methods of providing limited rotational motion in a thrust bearing assembly.

Compact thrust bearing assemblies, mechanical assemblies including the compact thrust bearing assemblies, and methods of providing limited rotational motion in a compact thrust bearing assembly are disclosed herein. The thrust bearing assemblies include a plurality of rigid load-bearing structures arranged in a layered stack that defines a first end and an opposed second end. The thrust bearing assemblies further include a plurality of rotation-limiting structures configured to restrict relative rotation between adjacent pairs of rigid load-bearing structures. The thrust bearing assemblies also include a first load-receiving surface configured to receive a first thrust load and a second load-receiving surface configured to receive a second thrust load. The methods include methods of providing limited rotational motion in a thrust bearing assembly.

A multi-blade rotor for a rotary wing aircraft, comprising a plurality of rotor that is connected to an associated rotor head via a plurality of flexbeam elements, wherein at least one flexbeam element of the plurality of flexbeam elements comprises an asymmetrical flexbeam root that is mounted to the associated rotor head.

A parking system for a propulsor teeter of an aircraft is disclosed. The system includes a propulsor including a hub. The hub is mechanically connected to a rotor, wherein the hub is configured to rotate about a rotational axis. A teeter mechanism is connected to the hub, wherein the teeter mechanism is configured to permit a propulsor plane of the propulsor to pivot with respect to a point of intersection between the propulsor plane and the rotational axis of the propulsor. A locking mechanism is configured to selectively lock the teeter mechanism while the aircraft is in flight, wherein selectively locking the teeter mechanism restricts the pivoting of the propulsor plane.

A monolithic blade of a rotorcraft rotor, the blade comprising at least locally an airfoil zone having a pressure side face and a suction side face. The invention is remarkable in that the blade has a root zone including a finger with a spherical bearing surface arranged at a root end of the blade, a recess suitable for receiving a laminated spherical bearing, and a flexible portion having a preferred direction of deformation in bending about a flapping axis of the blade, the flexible portion being arranged between the finger and the recess.