Abstract: A rotor hub assembly includes a yoke and a high capacity laminated (HCL) bearing, comprising layers of elastomeric material and layers of metal. The HCL bearing is affixed to the yoke to prevent separation of the HCL bearing from the yoke.

Abstract: A pitch bearing assembly for a rotor blade and a hub assembly of a rotary wing aircraft includes a single inner race. An inboard outer race surrounds an inboard portion of the inner race and includes a first inboard blade connector and a second inboard blade connector that are configured to connect to the rotor blade. An inboard bearing is disposed between the inboard portion of the single inner race and the inboard outer race and includes an elastomer. An outboard outer race surrounds an outboard portion of the single inner race and includes a first outboard blade connector and a second outboard blade connector that are configured to connect to the rotor blade. An outboard bearing is disposed between the outboard portion of the inner race and the outboard outer race and includes an elastomer.

Abstract: A hub system comprises at least one yoke, at least one shear bearing, and at least one mast adapter. The at least one mast adapter is configured to support the at least one yoke and the at least one shear bearing, and the at least one yoke has a flapping hinge that is non-coincident with a flapping hinge of the at least one shear bearing. Another hub system comprises a stacked yoke and a mast adapter. The mast adapter is configured to transfer rotation from a rotor mast to the hub system to rotate the hub system about a central axis of rotation. The mast adapter is further configured to support the stacked yoke such that each yoke in the stacked yoke is configured to accommodate at least some amount of rotation about an axis that is perpendicular to or about perpendicular to the central axis of rotation.

Abstract: A helicopter tail rotor gearbox including a housing, an output shaft for connection to a tail rotor rotatably supported in the housing and having an open end therein, an input member rotatably supported in the housing, gearing providing a power transmitting connection between the input member and output shaft, a pitch control shaft for effecting a change in the pitch of the tail rotor, the pitch control shaft being disposed at least partially within the output shaft, rotatable therewith, and movable relative thereto along the rotational axis of the output shaft, an actuating member for effecting axial movement of the pitch control shaft, the actuating member being movable axially of the output shaft but held against rotation therewith, and a bearing assembly positioned in between the pitch control shaft and the actuating member for permitting relative rotation therebetween, wherein the gearbox includes at least one formation for diverting oil, dispersed within the housing in use, towards the open end of the o

Abstract: An aircraft rotor assembly has upper and lower hub plates adapted to be mounted to a central rotor mast for rotation therewith. A plurality of radial arms is connected to at least two flap bearings mounted between the hub plates and forming a discrete flap hinge, each flap hinge defining a flap axis and allowing rotation of the associated arm relative to the hub plates and about the corresponding flap axis. Each of a plurality of blade grips is rotatably connected to one of the arms for rotation about a pitch axis and adapted for mounting of a blade to each blade grip, such that each blade is capable of rotation with the grip about the pitch axis and capable of rotation together with the corresponding arm relative to the hub plates and about the corresponding flap axis.

Abstract: A rotary system including a yoke having an opening forming a bridge for receiving a spoke extending therethrough. A rotor blade couples to the spoke and a pitch horn positioned outside the opening pitches the rotor blade during flight. A bearing assembly attaches the spoke and the pitch horn to the bridge and control blade forces exerted against the hub assembly during flight.

Abstract: The bearing system is configured for treating and reacting dynamic loading within a rotor hub of rotorcraft. The bearing system includes an outer member having a plurality of alternating outer elastomeric layers and shim layers. The outer member has an inboard surface configured for bonding to an inboard bearing support, and the outer member has an outboard surface configured for bonding to an outboard bearing support. The bearing system has an inner member bonded to an interior surface of the outer member. The inner member can include a rigid inner core, as well as a plurality of elastomeric layers and shim layers configured to react torsional movements of the rotor blade.

Abstract: According to typical inventive practice, a cylindrical or prolate spheroidal marine hull has two congruent contra-rotative propellers coaxially situated at or near its axial ends. Each propeller has plural blades mechanically and/or flexibly attributed with changeability of blade pitch angles and blade flap angles. A blade-pitch control system adjusts the individual blade pitch angles of both propellers. The blade-pitch control system may be electronically and/or mechanically actuated, and is capable of: (i) cyclically adjusting the blade pitch angles of the two propellers so as to select two respective blade-tip-path planes, each characterized by a direction of thrust that is associated with the blade flap angles and is generally perpendicular to the blade-tip-path plane; (ii) collectively adjusting the blade pitch angles of the two propellers so as to select two respective magnitudes of thrust.

Abstract: The present application includes a main rotor assembly for an aircraft. The rotor assembly has a main rotor mast configured for rotation about a mast axis and two yokes pivotally connected to the mast for rotation therewith about the mast axis. Each yoke is independently pivotable relative to the mast about at least one flap axis that is generally perpendicular to the mast axis. In at least one embodiment, a torque splitter connects the yokes and allows for limited rotation of the yokes relative to each other about the mast axis. Each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

Abstract: An omni-directional air flow device, for example, a fan or a vent associated with a fan, comprises a swivel control point providing almost a spherical range of motion of the air flow device so that air may flow in any direction. The omni-directional air flow device may comprise a user input device for receiving a program for controlling movement of the air flow device through a pre-determined path within the spherical range of motion and for controlling air flow velocity as the air flow device follows the pre-determined path. Moreover, the device may further comprise a controller and memory for storing data representing the pre-determined path and varying air flow velocities along the path. When provided with temperature and humidity sensors coupled to the processor, the processor may calculate a comfort index and adjust the pre-determined path or air flow velocity accordingly.

Abstract: A set (10) of cyclic swashplates (11, 12) for controlling the pitch of blades (4) of a main rotor (1) of a rotorcraft. The set includes a non-rotary swashplate (12) retained against rotation about an axis of rotation (AX) and a rotary swashplate (11) suitable for rotating about the axis of rotation (AX). The set (10) also includes drive means (100) with a drive arm (101) and an annular linear connection means (200) secured to the rotary swashplate (11). A first end (110) of the drive arm (101) is connected to the rotary swashplate (11) by the annular linear connection means (200). A second end (120) of the drive arm (101) is connected to a rotor mast (2) by slideway connection means (300) of the drive means (100).

Abstract: A rotor assembly includes a yoke operably associated with a rotor blade. The yoke includes a first device and a second device that attach the rotor blade to the yoke. The first device is configured to allow transverse movement of the rotor blade about a chord axis and rotational movement about a pitch-change axis. The second device is configured to allow rotational movement of the rotor blade solely about the pitch-change axis. The method includes rotating rotor assembly about a first plane of rotation, while retaining a relatively stiff out-of-plane rotation and a relatively soft in-plane rotation during flight.

Abstract: A shear bearing for a rotor system has a four bar linkage and a grip configured to retain a flexural yoke and the grip is connected between a first set of opposing links of the four bar linkage. A rotor system has a flexural yoke and a shear bearing configured to perform at least one of transmitting forces to the yoke and receiving forces from the yoke, wherein the yoke is free of cavities for receiving the shear bearing. A rotational system has a flexural yoke and a damper disposed on a surface of the yoke.

Abstract: A hub assembly for a tilt rotor includes a yoke having a plurality of yoke arms located substantially orthogonal to a central axis of the hub assembly. An inboard pitch change bearing assembly substantially surrounds a yoke arm of the plurality of yoke arms. An outboard pitch change bearing assembly is located at the yoke arm. The inboard pitch change bearing assembly and the outboard pitch change bearing assembly are operably connectable with a rotor blade to allow pitch change of the rotor blade relative to the yoke about a pitch change axis.

Abstract: A method of forming a rotorcraft blade is provided. A first support shaft (8) is secured to a rigid attachment filler (1) of the blade that is reversibly fastened to a mandrel (20). Fibers are placed around the assembly comprising said attachment filler (1) and said mandrel (20) in order to fabricate a spar of said blade, said spar (40) then including a succession of fiber layers (31, 32, 33) that hold said attachment filler (1) captive at the root (51) of said blade. Said first shaft (8) is removed after the spar has polymerized.

Abstract: A rotor for a helicopter, having a drive shaft rotating about a first axis; a hub angularly integral with the drive shaft about the first axis; and at least two blades projecting from the hub on opposite sides of the first axis and elongated along respective second axes crosswise to the first axis; each blade is movable with respect to the hub and to the other blade about a respective third axis crosswise to the respective second axis; the rotor has at least two dampers for damping oscillation of respective blades about the respective third axes, and which have respective first portions movable integrally with the respective blades about the respective third axes; and the dampers have respective second portions connected elastically to the respective first portions and functionally to each other.

Abstract: A constant-velocity drive system for a rotary-wing aircraft rotor comprising a differential torque-splitting mechanism and a gimbal mechanism is disclosed. A rotary-wing aircraft having a rotary-wing aircraft rotor comprising a differential torque-splitting mechanism and a gimbal mechanism is disclosed.

Abstract: Wind power plant rotor comprising one or more rotor blades and stiffening elements to stiffen the rotor, where the rotor blades are arranged such that they can turn around their longitudinal axes relative to corresponding rotor stiffening elements. Each rotor blade may comprise at least two rotor blade parts where the outer rotor blade part may be turnably arranged relative to the inner rotor blade part. The solution facilitates use of longer or slimmer rotor blades while strength and stiffness increase. The fatigue forces are thereby reduced while the corresponding tower structure can be made stiffer and lighter. Manufacturing and transport costs are reduced. Further, the stiffening elements may be formed with an aerodynamic outer cross section as for example a drop profile or wing profile in order to reduce air drag and audible noise.

Abstract: The present application includes a main rotor assembly for an aircraft. The rotor assembly has a main rotor mast configured for rotation about a mast axis and two yokes pivotally connected to the mast for rotation therewith about the mast axis. Each yoke is independently pivotable relative to the mast about at least one flap axis that is generally perpendicular to the mast axis. In at least one embodiment, a torque splitter connects the yokes and allows for limited rotation of the yokes relative to each other about the mast axis. Each yoke is configured for the attachment of rotor blades extending generally radially relative to the mast axis.

Abstract: A wind power plant has a turbine with its axis of rotation (1) substantially at right angle to wind direction, and wings (2) protruding from the axis (1) and the wings (2) have their crossways extension essentially in vertical direction. The wings (2) can be in odd as well as even number distributed around the axis of rotation (1), and composed of wing elements (21-24 and 31, 32) of optional length. For formation of the wings (2), the wing elements (21-24) are connected into a torsion link configuration (like a row of pairs of scissors), and thus synchronously movable in relation to each other. To adjust the extension of the wing elements (21-24 and 31, 32) an along the axis of rotation (1) adjustable sleeve means (4) is present, to which the inner end of an inner wing element (21) is connected.

Abstract: A variable blade pitch wind turbine and method of passively varying the blade pitch is presented. Each blade of the turbine rotor can individually and passively rotate about a respective blade axis to continuously vary the pitch of the blades to adjust to the ever changing wind speed and direction without active controls or other mechanical or electrical induced inputs to force rotational movement of the blades. Sections of each blade can respectively rotate to change the blade twist. In one example, a second rotor is used to increase the electrical generation and efficiency of the blade turbine.

Abstract: The catheter device comprises a drive shaft connected to a motor, and a rotor mounted on the drive shaft at the distal end section. The rotor has a frame structure which is formed by a screw-like boundary frame and rotor struts extending radially inwards from the boundary frame. The rotor struts are fastened to the drive shaft by their ends opposite the boundary frame. Between the boundary frame and the drive shaft extends an elastic covering. The frame structure is made of an elastic material such that, after forced compression, the rotor unfolds automatically.

Abstract: A stiff in-plane gimbaled rotor head for a rotorcraft, such as a helicopter, includes a vertically extending rotor shaft, a center hub disposed on the rotor shaft for conjoint rotation therewith, and an outer hub surrounding the center hub and coupled thereto through a spherical gimbal bearing for conjoint rotation therewith, and such that the outer hub is also capable of an angular range of gimbaling movement relative to the center hub. A plurality of rotor blades, which may include three or more blades, is coupled to the rotor shaft through the inner and outer hubs by a constant velocity joint that enables the blades to be rotated in a common plane about the axis of the rotor shaft while controlling the respective pitches of the blades and such that any other relative in-plane and out-of-plane movements of the blades during rotation is prevented.

Abstract: A yoke and bearing fitting assembly for a multi-blade aircraft rotor is disclosed. The assembly has a yoke having arms extending generally radially from a central portion of the yoke, the arms each having opposing surfaces. An aperture is formed in each arm and extends between the surfaces. A bearing fitting has a body configured for insertion into the aperture of the yoke and has two rims protruding from a periphery of the body, the body also having a bearing mount adapted for mounting a pitch change bearing assembly to the yoke. Each rim abuts one of the surfaces of the associated yoke arm when the bearing fitting is installed within the aperture, so as to create clamping forces between the rims and the arm and the arm. The bearing fitting transmits forces from the pitch bearing assembly into the yoke.

Abstract: An airfoil arranged for use in a fluid flow of varying direction relative to the airfoil, has arranged thereon a plural axis hinge for automatic adjustment of the angle of pitch of the airfoil. The airfoil can be applied to a rotary crossflow device for use in a fluid flow of varying apparent flow direction, an oscillating device for use in a fluid flow, a force generation device for use in a fluid flow of varying direction, or a flow control device for use in a fluid flow of alternating direction.

Abstract: A rotor-hub for a rotary-wing aircraft is disclosed. The rotor-hub comprises a yoke comprising a plurality of yoke arms and a plurality of yoke straps, wherein the yoke arms are joined together by the yoke straps, and wherein a plurality of inner walls of the yoke define a central void space. A pitch horn is movably connected to the yoke and a portion of the pitch horn is located within the central void space. A connecting shell is fixedly attached to the yoke.

Abstract: A rotor yoke includes a blade attachment portion, a mast attachment portion, and an intermediate portion extending between the blade attachment portion and the mast attachment portion. The intermediate portion, the blade attachment portion, and the mast attachment portion define an optional inner edge, such that the inner edge, if present, defines an opening. The rotor yoke further includes a peripheral, outer edge extending about the blade attachment portion, the intermediate portion, and the mast attachment portion. At least one of the outer edge and the inner edge, if present, includes a reduced thickness portion exhibiting a thickness that is less than a thickness of an adjacent portion of the rotor yoke.

Abstract: A method for connecting a tension-torsion strap. The method includes sliding a sleeve into an arm of a hub; aligning holes in the sleeve with holes in the hub; installing a bushing in each aligned hole in the sleeve; sliding a first end of the tension-torsion strap through the sleeve; and placing a pin through the bushings and the tension-torsion strap.

Abstract: The present invention relates to an improvement to rotorcraft rotors (1) fitted with inter-blade drag dampers (15) such that for each blade (4), the two joints (16) connecting said blade (4) to two inter-blade drag dampers (15) are disposed on either side of the pitch variation axis (101) of said blade, at least one of the two joints (16) being offset to above the plane P containing the pitch variation axis (101) and the vertical flapping axis (102).

Abstract: There is described a rotor for a helicopter, having a hub rotating about a first axis; a number of blades projecting from the hub in respective longitudinal directions lying in a plane crosswise to the first axis, and each connected to the hub so as to be movable at least about a second axis crosswise to the first axis and to the relative longitudinal direction; and a number of damping devices for damping vibration of the helicopter, each interposed between a respective blade and the hub; each damping device has a plate member fixed, on one side, to the hub, elastically connected, on the opposite side, to the relative blade, and flexible, during movement of the blade, about a third axis coaxial with the second axis.

Abstract: An assembly for providing flexure to a blade of a rotary blade system includes an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces has a layer of cushioning material positioned thereon and secured thereto. An alternate embodiment includes an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle. Another alternate embodiment includes a similar assembly having a twist-shank type of yoke for providing rotation of attached blades about their respective pitch axes.

Abstract: A rotor hub assembly for a rotary-wing aircraft has a central member and a plurality of blade grips adapted for attaching rotor blades to the central member. The blade grips are pivotally attached to the central member and are capable of pivoting about a pivot axis generally normal to a plane of rotation of the blades. The pivoting allows for in-plane motion of the blades relative to the central member. A damper is operably connected to each blade grip for damping the in-plane motion of the associated blade, each damper being selectively switchable between at least two spring rates.

Abstract: A rotor assembly having a rotor hub, a plurality of yokes, and a plurality of swing arms is provided. The yoke depending from the rotor hub. Each swing arm is movably positioned on the rotor hub for rotation between an unlocked position and a locked position. The yokes are freely movable about a pitch axis and a lead/lag axis when the swing arms are in the unlocked position and the yokes are locked in a predetermined pitch position and a predetermined lead/lag position when the swing arms are in the locked position.

Abstract: Rotor apparatus and methods for vertical lift aircraft are disclosed. In one embodiment, a bearing assembly adapted for rotatably coupling a rotor blade to a support member includes an inner housing annularly disposed about a portion of the support member, an outer housing annularly disposed about at least part of the inner housing and is rotatably coupled to the inner housing by an annular bearing device, and a flexible member adapted to be coupled to the support member and including an engagement portion adapted to engage the outer housing and to at least partially relax a side force exerted on the annular bearing device by a bending of at least one of the rotor blade and the support member.

Abstract: A wind turbine, having: (a) a rotatable frame; (b) a plurality of first air panels mounted to the rotatable frame, the plurality of first air panels extending in a direction parallel to an axis of rotation of the rotatable frame; (c) a plurality of second air panels mounted to the rotatable frame, the plurality of second air panels extending in directions radial to the axis of rotation of the rotatable frame; and (d) a base shaped to direct air flow received from a direction radial to the axis of rotation of the rotatable frame into a direction parallel to the axis of rotation of the rotatable frame.

Abstract: This invention relates to improving the performance of the conventional vertical windmills. The following strategies are employed to accomplish the objectives: Modularizing the vane assembly structure to scale up the size and capacity of the windmill without weakening its structural integrity. Reducing the frictional loss by using buoyancy bearing. Generating lift to harvest more energy stored in the wind. Applying the basic mechanical skill and using off-the-shelf parts to reduce initial investment and maintenance cost.

Abstract: An assembly for providing flexure to a blade of a rotary blade system, the assembly including an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween. At least one of the upper and lower yoke surfaces having a layer of cushioning material positioned thereon and secured thereto. The layer of cushioning material extending along and following the general contour of yoke surface, and the layer of cushioning material directly contacting a support plate. Another embodiment is an assembly for providing flexure to a blade of a rotary blade system, including, an upper support plate having an upper curved surface, a lower support plate having a lower curved surface, and a yoke positioned therebetween and directly contacting the support plates wherein one of the curved surfaces is a non-circular arc that does not form part of the circumference of a circle.

Abstract: An airfoil arranged for use in a fluid flow of varying direction relative to the airfoil, has arranged thereon a plural axis hinge for automatic adjustment of the angle of pitch of the airfoil. The airfoil can be applied to a rotary crossflow device for use in a fluid flow of varying apparent flow direction, an oscillating device for use in a fluid flow, a force generation device for use in a fluid flow of varying direction, or a flow control device for use in a fluid flow of alternating direction.

Abstract: The invention relates to a rotorcraft rotor comprising a hub and at least two blades hinged relative to the hub about respective pitch axes and about respective flap axes, and about respective lag axes; each blade is secured to a respective pitch lever; the rotor includes a respective pitch control rod connected to each pitch lever by a first ball joint, and a common lag damper system centered substantially on the axis of rotation of the rotor and connected to each of the blades; the damper system is secured to a respective lateral projection from each blade via a respective second ball joint that is sufficiently close to the first ball joint connecting the pitch rod to the pitch lever for the lag damper system to be relatively insensitive to flap oscillations of the hinged blades.

Abstract: A rotorcraft rotor includes a hub , a first blade having a first twistable structure secured to the hub by a first bolt and a first ring or washer , a second blade having a second twistable structure secured to the hub by a second bolt and a second ring or washer. The rotor includes a stop structure for preventing each ring or washer from turning relative to the hub or relative to the corresponding twistable structure.

Abstract: A multi-section blade for a wind turbine comprising at least one non-pitchable section and at least one pitchable section is provided. The non-pitchable section is configured to be fixed to a hub of the wind turbine. The pitchable section is configured to be rotated about a pitch axis which is substantially parallel to the span of the multi-section blade. A pitch bearing and a pitch motor are located within the blade and near the non-pitchable section and pitchable section interface.

Abstract: An improved waterwheel and methods for its use are provided. In an exemplary embodiment, the waterwheel is an undershot waterwheel utilized for electrical power generation. In another embodiment, the waterwheel may be partially or fully submerged. The waterwheel of the present invention may additionally be utilized to provide potable water, oxygen and hydrogen gases. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.

Abstract: The invention relates to a method for operating a wind power plant with a rotor and with at least two rotor blades rotatable about a common rotor axis in a rotor blade plane, whereof each can be swivelled about a swivel axis which is roughly parallel to its longitudinal axis approximately perpendicular to the rotor axis, in which the setting or pitch angels of the rotor blades are set with respect to the rotor blade plane as a function of the operating and in particular wind conditions, in which the pitch angels of at least two rotor blades in a parking position of the rotor, in which rotor rotation about the rotor axis is decelerated, are set to different values.

Abstract: An articulated rotor system with a servo-flap rotor control system locates the focal point of a blade retention spherical elastomeric bearing inboard of a joint in the servo-flap pitch control tube which separates the flap hinge and supports the servo-flap pitch control tube on a single pivot bearing within a blade retention spindle. Rotor blade flapping produces relative movements between the servo-flap pitch control tube and the blade retention spindle which is converted through a servo-flap drive linkage into servo-flap pitch motions to provide flap/pitch coupling which reduces steady and transient blade flapping.

Abstract: A rotor, especially for a rotary-wing aircraft, with a rotor mast and one or more adjustable rotor blades includes a rotor blade adjustment device without a swash plate and arranged on a carrier device that automatically rotates synchronously with the rotor blades, the rotor blade adjustment device rotating along with the carrier device in a manner that is free of relative movement with respect to the carrier device as well as with respect to the rotor mast and the rotor blades. The rotor blade adjustment device includes all of the blade actuators and kinematic elements required for a synchronized, cyclic and collective rotor blade adjustment as well as a control signal interface via which the control signals for the blade actuators can be transmitted from a stationary rotor section to the rotor blade adjustment device that is rotating along. Also, a rotary-wing aircraft, especially a helicopter, including at least one such rotor.

Abstract: In one embodiment of the present invention there is described a vehicle having a propeller mechanism for propelling the vehicle in a horizontal direction. The vehicle includes a transmitter positioned on the bottom of the vehicle for transmitting a signal from the vehicle downwardly away from the vehicle. A receiver is positioned on the bottom of the vehicle for receiving the signal as it is bounced off of a surface, defined as a bounced signal. A control system is also provided that automatically sets a speed of the propeller mechanism in response to the receiver. The control system sets the speed of the propeller mechanism to a first speed when the receiver receives the bounced signal and the control system sets the speed of the propeller mechanism to a second speed when the receiver does not receive the bounced signal. The first speed is predefined as a speed that causes the vehicle to gain altitude, while the second speed is predefined as a speed that causes the vehicle to lose altitude.

Abstract: The blade includes a current part (1) having an aerodynamic profile enclosing a spar (7) and extending from blade tip (4) to a blade root (3) provided with a pitch sleeve (21), through which twisting arm (6) passes and protrudes beyond blade root (3), and having a first part of a bundle (5) of superimposed and elongated metal strips, current part (1) including a block (13) based on synthetic material molded in form in a single piece around spar (7), and a second part of bundle (5) extending in line with the first part forming the twisting arm (6) and cooperating with the anchoring devices (14, 17) of the block (13) based on synthetic material around the spar (7).

Abstract: A rotor for a rotary wing aircraft includes a blade having a leading edge, and a trailing edge. The rotor has a leading edge tip extension at a tip of the blade and a weight within the leading edge tip extension. The rotor also includes a trailing edge tip extension extending from a selected point at an outboard portion of the blade to the tip of the blade, a leading edge of the extension extending rearward from the trailing edge of the blade.

Abstract: An elastomeric bearing system capable of sustaining a high compressive load is adapted to connect the blades of a helicopter rotor to a rotor hub. The bearing system comprises first and second elastomeric bearing elements fixed at the opposite ends of a tie bar. Said first elastomeric bearing element comprises a rigid external housing having an internal truncated-tapered surface with its minor basis directed inwardly, a rigid internal housing having an external truncated-tapered surface with its minor basis directed inwardly, and a resilient body between said internal and external truncated-tapered surfaces. Said second elastomeric bearing element is constituted by a chevron sub-assembly, comprising two tapered elastomeric bearing elements disposed with their minor basis facing each other, both having an individual internal housing and a resilient body and sharing a common external housing with a double-taper internal surface, the internal housings being connected one another by fastening elements.

Abstract: A snubber inner member has a doubly convex outer surface portion having a central longitudinal axis. A shim/spacer stack secured to the outer surface portion couples the snubber inner member to the second member. A retainer having one or more engagement surfaces cooperates with one or more engagement surfaces of the snubber inner member to constrain lateral movement of the snubber inner member relative to the retainer while permitting longitudinal movement of the snubber inner member away from the retainer. An elastomer secures the retainer to the first member.