Abstract: Methods and apparatus are provided for a controlled motor assembly for use in a reaction wheel assembly (RWA). The controlled motor assembly is optimized to work with an AC motor, and includes a filter configured to inhibit electrical and electromagnetic noise from being coupled between a spacecraft power bus and a power bus internal to the RWA, as well as an arrangement of power switch elements providing a path for motor phase currents associated with the AC motor. A digital control system is implemented to receive a command input, position sensor feedback and to retrieve parameters associated with the AC motor from a memory device. Based on the command input, the position sensor feedback and the parameters associated with the AC motor, the digital control system controls activation for the arrangement of power switch elements, and generates data output.

Abstract: Embodiments of a three parameter, multi-axis isolator configured to limit the transmission of vibrations between a mass and a base are provided. In one embodiment, the three parameter, multi-axis isolator includes an isolator housing configured to be mounted to the base, opposing bellows sealingly mounted within the isolator housing, and a damper piston movably suspended within the isolator housing between the opposing bellows. The damper piston is configured to be coupled to the mass. The opposing bellows deflect with movement of the damper piston along multiple axes to limit the transmission of vibrations between the mass and the base.

Abstract: Gas turbine engine, broadband damping systems, and methods for producing broadband-damped gas turbine engine are provided. In one embodiment, the gas turbine engine includes an engine case, a rotor assembly mounted within the engine case for rotation about a rotational axis, and a broadband damping system disposed between the rotor assembly and the engine case. The broadband damping system includes a first set of three parameter axial dampers angularly spaced around the rotational axis, and a second set of three parameter axial dampers angularly spaced around the rotational axis and coupled in parallel with the first set of three parameter axial dampers. The first and second sets of three parameter axial dampers are tuned to provide peak damping at different rotational frequencies to increase the damping bandwidth of the broadband damping system during operation of the gas turbine engine.

Abstract: Embodiments of a thermally-conductive vibration isolator are provided, as are embodiments of a spacecraft isolation employing a plurality of thermally-conductive vibration isolators. In one embodiment, the thermally-conductive vibration isolator includes a first end portion, a second end portion substantially opposite the first end portion, and first and second load transfer paths from the first end portion to the second end portion. The first and second load transfer paths comprise a main spring and a damper in parallel with the main spring, respectively. An elongated thermal conduit, which has a thermal conductivity exceeding that of first load transfer path and the second load transfer path, extends from the first end portion to the second end portion.

Abstract: Resilient aircraft engine mounts and mounting systems including the same are provided. A resilient aircraft engine mount comprises a base and a pair of opposed spiral springs in parallel forming a clevis with the base. A first spiral spring of the pair of opposed spiral springs has a first center opening extending therethrough. A second spiral spring of the pair of opposed spiral springs has a second center opening extending therethrough that is concentric with the first center opening for accepting a clevis pin. First and second spiral springs are each comprised of a rectangular cross section beam. The resilient aircraft engine mount is tunable in three translational axes to support three degrees of freedom vibration isolation. Two or more resilient aircraft engine mounts provide six degrees of freedom vibration isolation. Resilient aircraft engine mounts attach the aircraft engine to a pylon structure and help isolate vibratory forces.

Abstract: Embodiments of a low frequency isolation device are provided, as are embodiments of a spacecraft isolation system including a plurality of low frequency isolation devices. In one embodiment, the low frequency isolation device includes a three parameter isolator and a break frequency-reducing series spring mechanically coupled in series with the three parameter isolator and having a predetermined axial stiffness (KS AXIAL) and a predetermined lateral stiffness (KS LATERAL). The predetermined axial stiffness (KS AXIAL) of the break frequency-reducing series spring is less than the predetermined lateral stiffness (KS LATERAL) thereof.

Abstract: Resilient aircraft engine mounts and mounting systems including the same are provided. A resilient aircraft engine mount comprises a base and a pair of opposed spiral springs in parallel forming a clevis with the base. A first spiral spring of the pair of opposed spiral springs has a first center opening extending therethrough. A second spiral spring of the pair of opposed spiral springs has a second center opening extending therethrough that is concentric with the first center opening for accepting a clevis pin. First and second spiral springs are each comprised of a rectangular cross section beam. The resilient aircraft engine mount is tunable in three translational axes to support three degrees of freedom vibration isolation. Two or more resilient aircraft engine mounts provide six degrees of freedom vibration isolation. Resilient aircraft engine mounts attach the aircraft engine to a pylon structure and help isolate vibratory forces.

Abstract: Systems are provided for damping vibrations from a payload. In an embodiment, and by way of example only, the system includes an isolation strut and a gas line. The isolation strut includes a bellows and a piston. The bellows has a first end and a second end, the first end being enclosed, and the second end attached to the piston to define a chamber. The piston includes a damping annulus therethrough having a gas inlet and a gas outlet. The gas inlet provides flow communication to the chamber of the bellows. The gas line is coupled to the isolation strut and is in fluid communication with the gas outlet thereof. The system is hermetically sealed to contain a gas therein.

Abstract: Gas turbine engine, broadband damping systems, and methods for producing broadband-damped gas turbine engine are provided. In one embodiment, the gas turbine engine includes an engine case, a rotor assembly mounted within the engine case for rotation about a rotational axis, and a broadband damping system disposed between the rotor assembly and the engine case. The broadband damping system includes a first set of three parameter axial dampers angularly spaced around the rotational axis, and a second set of three parameter axial dampers angularly spaced around the rotational axis and coupled in parallel with the first set of three parameter axial dampers. The first and second sets of three parameter axial dampers are tuned to provide peak damping at different rotational frequencies to increase the damping bandwidth of the broadband damping system during operation of the gas turbine engine.

Abstract: Embodiments of a thermally-conductive vibration isolator are provided, as are embodiments of a spacecraft isolation employing a plurality of thermally-conductive vibration isolators. In one embodiment, the thermally-conductive vibration isolator includes a first end portion, a second end portion substantially opposite the first end portion, and first and second load transfer paths from the first end portion to the second end portion. The first and second load transfer paths comprise a main spring and a damper in parallel with the main spring, respectively. An elongated thermal conduit, which has a thermal conductivity exceeding that of first load transfer path and the second load transfer path, extends from the first end portion to the second end portion.

Abstract: Embodiments of a three parameter, multi-axis isolator configured to limit the transmission of vibrations between a mass and a base are provided. In one embodiment, the three parameter, multi-axis isolator includes an isolator housing configured to be mounted to the base, opposing bellows sealingly mounted within the isolator housing, and a damper piston movably suspended within the isolator housing between the opposing bellows. The damper piston is configured to be coupled to the mass. The opposing bellows deflect with movement of the damper piston along multiple axes to limit the transmission of vibrations between the mass and the base.

Abstract: Systems are provided for damping vibrations from a payload. In an embodiment, and by way of example only, the system includes an isolation strut and a gas line. The isolation strut includes a bellows and a piston. The bellows has a first end and a second end, the first end being enclosed, and the second end attached to the piston to define a chamber. The piston includes a damping annulus therethrough having a gas inlet and a gas outlet. The gas inlet provides flow communication to the chamber of the bellows. The gas line is coupled to the isolation strut and is in fluid communication with the gas outlet thereof. The system is hermetically sealed to contain a gas therein.