Abstract: A mounting (20) which provides superior isolation yet which eliminates damaging edge-induced shear strain (ENT) buildup in the elastomer sections (28) and (30) when exposed to high temperatures by having a first elastomer section (28) loaded in compression and a second elastomer section (30) loaded in shear. Exposing the mounting (20) to elevated temperature environments allows the first elastomer section (28) to expand in height and places the second elastomer section (30) in shear to accommodate the height change. The instant invention compensates for fluid and elastomer expansion due to high temperatures by providing a mechanical type compensator (37) which takes up less space and eliminates the pressure loss associated with air-charged compensators (99). Further, a unique combination of fluorinated fluids and polysiloxane polymer enables the mounting (20) to withstand temperatures of greater than 200 deg F. for extended periods of time.

Abstract: A flexibly-mounted active vibration absorber (AVA) which has a secondary controllable mass M.sub.3. If the passive resonance of mass M.sub.2 of the tuned absorber is insufficient to control the input vibration, a secondary mass M.sub.3 is vibrated at a frequency, amplitude and phase sufficient to make up the deficiency in mass M.sub.2. Many embodiments are described which depict variations on the first spring used for flexibly mounting the AVA, the actuators used to drive the AVA, and the attachment features for attaching to a vibrating member. Further in another aspect, means for counterbalancing the moments produced by the AVA are described.

Abstract: A damping device which provides superior damping stiffness K", has linear damping characteristics as a function of amplitude and for which the temperature sensitivities of stiffnesses K*, K", K' have been minimized. The device includes a first second fluid-filled chambers which are interconnected by a passageway. The length and diameter of the passageway, as well as the fluid viscosity, are chosen to give the optimum damping characteristics. Further, a plurality of spring loaded pressure relief valves are integrated into the assembly to allow more flow area to open when a threshold pressure is encountered, thereby reducing the internal pressures and dynamic stiffness K* at cold temperatures.

Abstract: A mounting (20) which provides low vertical and lateral spring rates for excellent lateral and vertical vibration isolation yet provides a high roll stiffness for reacting torsional moments, while reducing isolator complexity and eliminating the need for a yoke or hanger. The mounting (20) includes a top member (34), a first arm (26) and a second arm (28) which are flexibly interleaved or attached. The first arm (26) is attached to a top member (34) by way of a pivot which can be a spring (30), the second arm (28) is also attached to the top member (34) by another pivot which can be a spring (32), and a third spring (36) attaches the arms (26) and (28) to each other. The arms (26) and (28) also attach to the supported member (22) preferably at their respective outboard ends (38), or at least one intermediate link can be used.

Abstract: A pivot type aircraft mounting for resiliently connecting a structure to an aircraft engine which uses a pivoting and siding joint on a beam at the engine attachment point, a vertically stiff and laterally soft intermediate pivot joint on the beam, and a resilient compression section near the end of the beam for reacting the engine loads into the structure and providing the desired spring rates in the vertical and lateral direction. The invention can utilize low friction pivoting and sliding joints such as nylon lines bearings or elastomeric bearings. The compression section can be metal mesh for high temperature applications or of elastomeric or laminated elastomeric construction for normal operating temperatures. The remote location of the compression section is particularly well suited for addition of fluid for adding damping or tuned absorber effects.

Abstract: A vibration isolating mount for connecting spaced structures and limiting noise transmission between the connected structures, such as between an aircraft and a turbine engine. The isolator comprises a pair of arms which are interconnected at one location by a torque tube pivotally connected to the aircraft structure and which are interconnected at another location by a tie brace which is also connected to the aircraft structure by a vibration isolator pad. The engine is connected to the arms by a hanger. The mount accepts various engine leads and reactions while minimizing the transmission of engine noise into the cabin of the aircraft.

Abstract: A strut for mounting an engine and isolating the vibration of the engine from the framework of an aircraft to which it is attached. An engine mounting strut (32) includes a forward spar (40), which extends outwardly from a rib (34) of an aircraft (20). An aft spar (62) similarly extends outward from a rib (38) and is pivotally connected to a box beam (42) in a vibration isolation mount (78). The pivotal axis of mount (78) is generally aligned with the longitudinal axis of the box beam. A vibration isolation arm (44) extends from a pivotal connection (82) having an axis generally orthogonal to the longitudinal axis of the box beam and is connected to the forward spar at two spaced-apart vibration isolation mounts (46 and 84). The spars are enclosed with an aerodynamic skin (56) forming a torque box 48, to which are attached forward and aft fairings (58).

Abstract: A link-type coupling particularly suited for use in connecting a drive shaft to a rotor hub in an aircraft for permitting the hub to rotate about an axis that may be angularly misaligned with respect to the rotational axis of the drive shaft. The coupling includes a series of links arranged tangentially with respect to the hub and shaft and connected thereto by laminated elastomeric bearings at the ends of the links. The laminated elastomeric bearings accommodate the motion of each link while transferring torque between the shaft and hub.

Abstract: A rotor blade retention system connects an elongated rotor blade to a rotor hub that is rotatable about its central axis. The connected rotor blade normally extends generally radially from the hub and is rotatable with the hub. The retention system includes at least three laminated elastomeric bearings connected together in serial compression load transmitting relationship. Each laminated bearing includes a plurality of alternating and bonded together layers of elastomeric material and substantially inextensible material. The layers of each of the serially interconnected bearings are at least partially inclined relative to the longitudinal axis of the rotor blade. In section taken radially of the longitudinal axis of the blade, at least a portion of each layer of each bearing projects longitudinally toward an end of the rotor blade. Preferably, only one of the serially interconnected bearings is rigidly connected to the rotor blade.

Abstract: A compressive load carrying laminated bearing comprising alternating bonded layers of a resilient material and a non-extensible material generally concentrically disposed about a common center with successive layers being disposed at successively increasing radii. The fatigue life thereof, when subjected to cylic rotational or torsional motion about the common center, is substantially enhanced by progressively increasing the thickness of the layers of resilient material with increasing radii while simultaneously progressively decreasing the modulus of elasticity of the layers of resilient material with increasing radii. .Iadd.