Abstract: A light weight fuel tank for a hydrogen powered airplane used as a platform for communication repeaters for communication services. An outer spherical shell member of a sandwich configuration surrounds an inner thin walled spherical shell member in which the liquid hydrogen is contained. A radial gap between the shell members is evacuated to a high vacuum. The facing surfaces of the shell members are coated with a low emissivity material. Electrical heaters are provided to control the evaporation rate of the hydrogen to match the fuel usage and to prevent icing during ascent and descent of the airplane.

Abstract: A method, apparatus, for subjecting a test object to vibrational energy testing is disclosed. The apparatus comprises a rotatable joint such as a hydrostatic ball joint for transmitting energy from a force generator to the test object, and a support structure, coupled to the test object and the rotatable joint, for flexibly restraining the test object from rotating about the center of rotation of the rotatable joint. In one embodiment of the invention, the support structure comprises a support member and at least one suspension device disposed between the support member and a ground datum. In another embodiment, the suspension device applies a suspension force to the support member in a direction substantially perpendicular to a vector from the center of rotation to the suspending force. In this embodiment the suspension devices are subjected primarily to compression and tension forces.

Abstract: A flywheel assembly for storing energy and rotatable in response to the rotation of a shaft includes a hub having a transition portion having a constant stress intermediate region operatively coupled to the shaft and an outer connecting portion forming a flexible cylinder, wherein the shaft and the flexible cylinder are substantially coaxial, and an outer cylinder wherein a majority of the mass of the flywheel assembly is concentrated. The flexible cylinder includes connecting pads disposed at opposing edges of the outer side of the flexible cylinder thereby permitting connection to the outer cylinder. The outer cylinder increases radially responsive to a corresponding increase in rotational speed of the flywheel assembly, while the diameter of the transition portion of the hub follows the radial increase of the outer cylinder.

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft (20) coincident with a main rotation axis included in a flywheel (10) used for energy storage and high surge power in vehicular applications. The bearing system includes upper and lower radial force generators (110, 210) containing only electromagnets, and upper and lower axial force generators (120, 220) including an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the bearings includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a preferred bearing stiffness. The bearing system also includes upper and lower touchdown ball bearings (130, 230) which are engaged only when the radial force generators are unable to maintain the rotor in a predetermined cylindrical volume within the flywheel (10).

Abstract: A bearing system for positioning and supporting a rotor having a vertical shaft coincident with a main rotation axis included in a flywheel used for energy storage and high surge power in vehicular applications includes first and second radial force generators disposed in a first plane perpendicular to the rotation axis of the rotor, the first and second force generators including only electromagnets, third and fourth radial force generators disposed in a second plane perpendicular to the rotation axis of the rotor, the third and fourth force generators including only electromagnets, and upper and lower axial force generators each containing an electromagnet and a permanent magnet. According to one aspect of the bearing system, each of the force generators includes control circuitry having simple and complex lead networks so as to permit the force generators to rapidly respond to vehicular transients while maintaining a desired bearing stiffness.