Abstract: The technique of shrink fitting technique described herein is used to bond crystalline sapphire pieces to each other, in particular, the shrink fitting of a c-axis sapphire post to a c-axis sapphire puck. The sapphire dielectric resonator is used successfully from cryogenic temperatures to well above room temperature. The shrink fit bond yields a high strength and rigid attachment which can withstand high shock levels. Since there is no loss, the resonator Q is a maximum, being limited by the sapphire loss tangent only.

Abstract: A high-volume source for very low frequency applications in which conventional speakers are inadequate is disclosed. A presently preferred embodiment comprises a reservoir 32 with a pressure relief 33; a controller 34; a supply blower 36; an exhaust blower 38; a positive plenum 40; a negative plenum 42; an orifice plate with valving 44; a horn 46; and pressure transducers 48, 50, 52, 54, feeding detected pressure levels to the controller 34. An electrical command signal s(t) is also input to the controller. The command signal is a voltage analogous to the acoustic pressure or volume velocity to be output by the source.

Abstract: A bidirectional variable reluctance linear actuator and force control system by which one or more bidirectional linear actuators can be operated to produce a linear relationship between the net force on the armature structure and an applied flux linkage variation signal, as well as an actuator system by which the transmission of vibration through a structure can be blocked by applying forces and/or moments to the structure so as to cancel out its vibratory velocity. An adaptive control system, which is synchronized to machine speed, is able to determine the proper forces that will cancel the vibration of the structure and automatically null out each harmonic of the structure vibration, and cancels the vibration in up to six degrees of freedom of structural motion. The system can provide active attenuation system with a variety of noise sources and transmission paths, i.e.

Abstract: A structureborne vibration-compensated motor arrangement includes a pair of twin AC motors supported by a rotatable shaft structure and a stationary outer housing. Each motor includes an annular stator core structure and an annular rotor field structure. The stator core structure is mounted by an annular stator support member which, in turn, is stationarily supported by the outer housing. The rotor field structure is mounted by an annular rotor support member in spaced relation, either axially or radially, from stator core structure. The rotor support member, in turn, is mounted to the rotatable shaft structure for rotation therewith.

Abstract: This invention is a support spring made of a material, such as aluminum, that is damped by friction forces to directly support a sapphire dielectric resonator operating from a cold finger at cryogenic temperatures in a spring-mounted enclosure to reduce a phase-noise vibration sensitivity of the sapphire dielectric resonator. The support spring provides vibration isolation in al three directions, along with good thermal conductivity to aid in resonator cool-down. A damper clamp and damper clips provide the friction forces necessary for damping which prevents large vibration transmission peaks in a hostile, low-temperature, high-vacuum environment.