Abstract: An air cycle environmental control system for high pressure water separation omits a condenser heat exchanger and includes a reheater capable of placing compressed air in a heat exchange process to condense water vapor. A first turbine is in direct flow communication with the reheater, while the first turbine is capable of condensing water vapor from the compressed air. A water extractor is in flow communication with the first turbine and the reheater, while a second turbine is downstream of the reheater. The second turbine is capable of cooling a reheated, dehumidified air from the reheater to produce a conditioned air for supply to an enclosure. A method of water separation from a high pressure water vapor bearing air omits a step of condensing water vapor in a condenser heat exchanger and includes the steps of cooling a compressed air in a reheater heat exchanger such that the compressed air becomes a cold air. Water vapor is then condensed from the cold air to become a dehumidified air.

Abstract: A method of brazing a Ti-15 Mo-3 Nb-3 Al-0.2 Si base material includes the steps of coating a braze material onto a base material. The braze material comprises substantially only a Ti--Cu--Ni--Zr mixture, with the mixture comprising about 40 wt % Ti. In particular, the braze material may comprise 40Ti-20 Cu-20 Ni-20 Zr. A following step includes heating the braze material and then forming a braze joint between the braze and base materials. The heating step can occur from about 760 to 932.degree. C. and over 15 to 90 minutes.

Abstract: A brake mechanism includes an inner assembly secured to a motor shaft and an outer assembly surrounding the inner assembly. The outer assembly includes a permanent magnet or an electromagnet between a pair of ferromagnetic pole structures. The inner assembly also includes a pair of ferromagnetic pole structures. During operation of the brake mechanism, the inner assembly is rotated relative to the outer assembly, and the pole structures cause a magnetic field within the inner assembly to pulsate. The pulsating magnetic field causes the inner assembly to apply a braking torque to the shaft.

Abstract: A cylindrical shaft including a rotor rotates within a housing. A foil bearing comprised of flexible foil segments encircles the rotor, and is located in between the rotor and the housing. The foil segments are attached to the housing, and are installed with a flexion to press against the rotor. A split ring is situated near each end of the foil bearing. Each ring is suspended in an circumferential groove in the rotor by springs which also apply a force tending to keep the ring closed. When the rings are closed, the foil segments can press against and support the rotor. The rings can be opened by respective solenoid-operated plungers to press against the foil segments and force them apart from the rotor.

Abstract: Metal and ceramic members are joined together by a braze joint including a member made of bar stock molybdenum, a first ductile member brazed between the molybdenum member and the metal member, and a second ductile member brazed between the molybdenum member and the ceramic member. The braze joint may be used to join a ceramic wheel shaft to a metal shaft in a turbomachine. The braze joint allows torsion to be transmitted between the ceramic wheel shaft and the metal shaft without the use of a metal sleeve.

Abstract: An environmental control system provides for two stage compression and expansion of a bleed air within a cooling cycle, while allowing for a separately driven fan to handle ambient air as a heat sink. The system comprises a plurality of compressors capable of compressing a water vapor bearing air to produce a compressed air. A reheater is capable of cooling the compressed air. A condenser is in flow communication with the reheater, with the condenser being capable of condensing the water vapor. A water extractor is in flow communication with and intermediate of the condenser and the reheater. A plurality of turbines are in flow communication with and downstream of the reheater.

Abstract: A ram air turbine includes a reaction turbine and an electrical generator that is driven by shaft power of the reaction turbine. A scoop directs a flow of ram air to an inlet of the reaction turbine and creates a pressure head for the reaction turbine. The reaction turbine and the scoop are contained entirely within a pod. The ram air turbine further includes a turbocompressor, including a turbine stage and a compressor stage, which provides a stream of cooled air to equipment inside the pod. The turbocompressor also reacts loads shed by the electrical generator.

Abstract: A rotor assembly includes a lamination stack, a pilot shaft for providing radial piloting for the lamination stack, and clamp for applying an axially compressive force to the lamination stack. Decoupling the piloting from the clamping allows the diameter of the rotor assembly to be increased. Resulting is a rotor assembly having a shorter axial length and higher tip speed.

Abstract: An air conditioning system for an aircraft includes cascaded high and low pressure turbines, an electric generator that is driven at variable speeds by the low pressure turbine, and a fan that is also driven by the low pressure turbine. During operation of the air conditioning system, ac power is generated by the electric generator and provided to electrical equipment onboard the aircraft. Because the electric generator is driven at variable speeds, it generates ac power having variable frequency. The air conditioning system further includes a bypass valve for bypassing the high pressure turbine when speed of the electric generator approaches a lower limit. Bypassing the high pressure turbine allows generator speed to be increased. The fan has a speed-cubed load characteristic that maintains the generator speed below an upper limit. Thus, the bypass valve and the fan can be used to limit the speed of the electric generator and thereby maintain frequency of the ac power between upper and lower limits.

Abstract: A winding wedge retention system designed to maintain coil form includes a rotor (21) having a plurality of rotor poles (24), a coil (20) wound on one of the rotor poles (24), a V-shaped support wedge (22) positioned between adjacent rotor poles (24, 24) and that is adapted to support the coil (20), and a second wedge (26) that is positioned between and adjacent to the coil (20) and the rotor pole (24) on which the coil (20) is wound. The second wedge (26), in the presence of centrifugal loads, maintains a constant shape of the coil (20) and also maintains a constant position of the coil (20) relative to a position of the support wedge (22).

Abstract: A transformer-coupled load driver (10) is adapted to provide a constant level of output current under condititons of variable input voltage and/or variable load resistance. The load driver (10) is provided with a current sensing resistor (30) which is included in an output branch (14) of the transformer (12). A pulse-width modulator (18) is used in conjunction with a voltage divider network (20) to sense current flow through the resisitor (30) and to control the current output of the branch (14) via modulation of a control signal delivered to the gate of a transistor (16).

Abstract: A hydrophilic antimicrobial coating includes a porous ceramic-based coating and at least one biocide dispersed in the porous, hydrophilic ceramic-based coating. The coating can be an alumina coating, and the biocide can include silver oxide. A second biocide such as zinc oxide or copper oxide can also be dispersed in the porous, hydrophilic ceramic-based coating. The hydrophilic antimicrobial coating can be applied to a heat transfer surface of a heat exchanger.

Abstract: A bearing detection system for an electrical generator (10) includes auxiliary bearings (29) for supporting a rotating shaft (39) upon failure of main bearings (62). The auxiliary bearings (29) are mounted on the shaft and have a slight gap (64) between their outside diameters and bearing liners 33. The gap corresponds to the main bearing permissible wear. During normal functioning of the main bearing, the auxiliary bearing frame (34) rotates with the shaft and a magnet (35) with a small clearance between its face and auxiliary bearing outer ring (32) forces the synchronized rotation of inner (37) and outer (32) races. The auxiliary bearing outer ring or race (32) has a coaxial groove (31) on its outer diameter and a detection sensor (30), mounted on the bearing liner, gives a signal per rotation of the shaft to a control circuit (40).

Abstract: An environmental control system includes a single heat exchanger, a single water separator and two air cycle machines on separate spools. Cooling turbines of the air cycle machines are cascaded. Air flows through both air cycle machines during normal operation of the environmental control system. If one of the air cycle machines fails, air can be bypassed around the failed air cycle machine. Cascading allows water separation to be performed by a mid-pressure water separator located between the air cycle machines.

Abstract: An environmental control system includes an air cycle machine, an electrical machine coupled to the air cycle machine, and a controller for the electrical machine. The controller can cause electrical energy to be extracted from the electrical machine whenever cooling capacity and/or airflow rate of the air cycle machine are greater than necessary. The electrical machine can also be operated as a motor to increase the airflow rate and cooling capacity of the air cycle machine.

Abstract: A decoupling apparatus for disconnecting an engine starter from an engine includes a first rotatable decoupler shaft, having a first clutch jaw, coaxially mounted with respect to a second rotatable decoupler shaft having a second clutch jaw. The two shafts can translate relative to each other from a first position in which the first and second clutch jaws are engaged to a second position in which the jaws are disengaged. A torsional shear pin with a unitary shaft has a first end in contact with a resilient member and a second end attached to the first decoupler shaft, thereby urging the first and second decoupler shafts into the first position. The torsional shear pin is frangible in response to angular movement of the first decoupler shaft relative to the second decoupler shaft to release the axially compressive force, thereby permitting the first and second decoupler shafts to move into the second position.

Abstract: A vibration damped turbo-machine blade includes a shot peened metallic substrate which provides a shape for the blade. Carried on the metallic substrate and bonded to an outer surface of this substrate is a singular ceramic coating of a damping material. The substrate may be made of forged titanium, and the coating may be made of a ceramic material including cobalt at a weight percentage of from about 13% to about 21%, with the balance of the ceramic material being substantially all tungsten carbide.

Abstract: A high aspect ratio, low solidity fan blade of an axial flow air cycle machine has a local tip center of gravity axis that has been shifted ahead of an elastic axis. The center of gravity axis can be shifted by clipping the tip of the blade at the trailing edge, by undercutting a rear portion of the pressure surface, or by sweeping forward leading and trailing edges of the blade by about five degrees (without clipping or undercutting the blade).