Abstract: An anti-torque mechanism which permits a full range of swashplate assembly motion. The anti-torque mechanism generally includes an anti-torque shaft and a compound bearing mounted thereto to provide five-degrees-of-freedom (spherical-linear-elastomeric) so as to permit a swashplate attachment point to move axially in response to pitch input; pivot in response to swashplate tilt; and move in/out in the radial direction.

Abstract: An anti-torque mechanism which permits a full range of swashplate assembly motion. The anti-torque mechanism generally includes an anti-torque shaft and a compound bearing mounted thereto to provide five-degrees-of-freedom (spherical-linear-elastomeric) so as to permit a swashplate attachment point to move axially in response to pitch input; pivot in response to swashplate tilt; and move in/out in the radial direction.

Abstract: A helicopter rotor has two or more blades which extend from a hub and has an adjustment mechanism for adjusting the lead/lag variation of the blades which typically occur due to manufacturing tolerance variations or to changes which occur through operation such as softening of the supporting elastomer dampers. One embodiment of the invention incorporates an end plate on an upper damper with a lug positioned adjacent to a lug on the torque tube such that the end plate of the damper can be changed relative to the longitudinal axis of the blade. For example, a .+-.1/2 degree adjustment can be made in the blade angle relative to the hub to insure that lead/lag errors are reduced. In another embodiment, the damper set includes extended metal shims adjacent to the end most laminate plys of the upper and lower dampers such that these shims can be bolted to the end plates of the snubber assemblies for step increasing the stiffness of the assemblies.

Abstract: A mounting arrangement (60) for coupling a control rod (38) to a stationary swashplate member (32) of a helicopter swashplate assembly (30) wherein the mounting arrangement (60) is characterized by a specially configured stationary swashplate member (32) and a trunnion fitting (62) for mounting in combination therewith. More specifically, the stationary swashplate member (32) includes a horizontal web (74) disposed between an inner ring segment (72.sub.IR) and an outer ring segment (72.sub.OR), wherein the horizontal web (74) includes an aperture (78) and defines a mounting surface (74.sub.S). The trunnion fitting (62) includes a base (64) defining a mounting surface (64.sub.S) and a pair of mounting ears (66) having aligned apertures (66.sub.O). The mounting surface (64.sub.S) of the trunnion fitting (62) engages the mounting surface (74.sub.S) of the horizontal web (74) such that the mounting ears (66) are disposed through the aperture (78) of the horizontal web (74).

Abstract: One embodiment of a main rotor pitch control rod subassembly includes an upper rod end segment having a bearing subassembly, a lower rod end segment having a bearing subassembly, an eccentric bushing disposed in rotatable combination with the upper rod end segment bearing subassembly for varying the axial length of the pitch control rod subassembly, a composite central body structure interposed between the upper and lower end segments, a composite strap member wrapped around and secured in combination with the lower end segment bearing subassembly, the composite central body structure, and the upper end segment bearing subassembly, eccentric bushing combination, a composite overwrap overlayed in combination with the composite strap member, a locking key member and a clamp-up bolt for clamping the composite strap member in tensioned combination with the locking key member, and a locking bolt.

Abstract: A mid-beam jointed reconfigurable bearingless main rotor (BMR) assembly that includes reconfiguration joints that facilitate BMR assembly reconfiguration by main rotor blade removal or folding to reduce the structural envelope of a helicopter for rapid deployment, routine transport, and/or storage. The BMR assembly comprises a rotor hub structure that includes a plurality of radially extending flexbeams, combinations of torsion flexure members and main rotor blades disposed in combination with corresponding flexbeams, and torque tube subassemblies disposed in combination with corresponding flexbeams and torsion flexure member, main rotor blade combinations. Each reconfiguration joint is formed by a combination of an outboard joint segment of a flexbeam and an inboard joint segment of the corresponding torsion flexure member.

Abstract: Main rotor pitch control rod assemblies on helicopters constitute means for ranslating an aviator's control impulses in the cockpit to the main rotor blades. Pitch control rod assemblies typically include means for locking the assembly into a predetermined attitude setting. The setting may be held by locking nuts. This invention provides a passive locking means using spring tension to maintain the desired setting if the locking nuts loosen due to stress loads or improper torquing during maintenance. The invention also provides passive means for maintaining expansive stress within the control rod to prevent distortion of the assembly under compressive loads.

Abstract: A swashplate configuration for a helicopter which eliminates the need for a uniball centering bearing and either a stationary or rotating scissors linkage through the use of elastomeric bearing assemblies consisting of a first stack of flat laminates oriented both vertically and radially with respect to the axis of the main rotor shaft and a second stack of spherical laminates having a center axis oriented radially with respect to the main rotor shaft axis and which reacts centering and torque loads through compression of the laminate stacks.

Abstract: A flexible composite scissor assembly is disclosed which utilizes one or more composite straps disposed either in a radial or non-radial relationship between a hub attached to a rotor and an inner or outer ring of a helicopter swashplate. The composite material has sufficient edge-wise stiffness to allow effective torque transmission between the rotor shaft and the swashplate yet has sufficient flexibility to allow for a vertical and angular displacement of the swashplate relative to the rotor shaft. Utilizing a flexible composite scissor assembly eliminates the need for mechanical linkages having pins and bearings which are a frequent source for wear, increasing the reliability of the rotor assembly, while reducing weight.