Abstract: This invention relates to an airconditioning system to provide environmental control for an aircraft's cabin or cockpit. The system cooling cycle includes in combination: a rotary power supply and a turbomachine which includes a power compressor secured to a power shaft for providing compressed air. The rotary power supply is drivingly coupled to the power shaft to operate at a given speed. An expansion cooling turbine is mounted on a shaft concentric to the power shaft. A power driven fan is provided for directing a source of ambient air to and through a heat exchanger. The power compressor is coupled respectively to the cabin and through the heat exchanger to an input of the expansion cooling turbine to thereby draw air from the cabin and deliver the compressed air to the expansion cooling turbine. The expansion cooling turbine is designed to operate at a different speed than the given speed of the power shaft.

Abstract: In an assembly, for use in transducer type instruments such as accelerometers, having a position sensing movable member including a pick-off element, wherein the movable member is secured to a support member by a flexure or hinge and the support member in turn is cantilevered between two stator members, instrument bias errors resulting from the securing of the non-cantilevered portion of the support member between the stator members can be reduced by aligning the edges of the surfaces of the stators that contact the support member with the centroid of the pick-off element so that the axis of cantilever rotation passes through the centroid of the pick-off area. In transducers having electrical leads on the movable member, the flexure and the support member for electrically connecting the pick-off element to the support member, bias errors can be further reduced by including the area of the electrical leads in calculating the centroid.

Abstract: In a gearbox for an aircraft, a multiple stage separator is attached to a gear journaled within the gearbox housing. An axial bore extends at least partially through the shaft supporting the gear and opens into a discharge chamber which communicates with an atmospheric vent. A first stage of the separator includes an impeller attached to one face of the gear and a second stage includes a series of angularly spaced passages extending in a generally radial direction through the shaft to communicate with the bore. A sleeve telescoped into a reduced section of the inner end of the bore receives the incoming mixture of air and oil and directs the air into an enlarged outer end section of the bore wherein final stage separation of air and oil occurs. A member including an aperture concentric with the central axis of the bore keeps the oil collected along the walls of the bore from entering into the discharge chamber.

Abstract: In an aircraft excessive rate of descent warning system that utilizes barometric descent rate compared with aircraft altitude above ground to generate a warning, nuisance warnings at airports having terrain that slopes generally downwardly towards the runway can be substantially reduced by modifying either the descent rate signal or the altitude above ground signal as a function of radio altitude rate thereby having the effect of increasing the descent rate required to trigger a warning when the aircraft is descending essentially parallel to the ground.

Abstract: In order to facilitate construction of a compact, lightweight servoed accelerometer with capacitive pick-off, a one-piece support frame, adapted to be inserted within a cylindrical housing, is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum or seismic mass having a paddle on one end. The paddle is positioned midway between the capacitor plates, thereby forming a pair of capacitors each having a capacitance on the order of 2 to 4 picofarads. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. The ends of the flexures are rigidly secured to the support frame, and a desired pressure of the bearings against the axle is maintained by means of adjustment screws.

Abstract: In order to reduce bias errors resulting from mounting of a force restoring coil assembly element of a force balancing transducer, the force coil assembly is suspended by means of one or more hinges from a force sensing movable member, which includes position pick-off means, that in turn is connected by hinging means to a support member. The effects of strain may further be reduced by locating the first hinges essentially along the axis of the centroid of the pick-off means.

Abstract: An arrangement for mounting a gear on a drive shaft of a fuel pump includes a longitudinal slot dividing one end portion of the shaft into first and second cantilever sections. Shoulders formed in the slot on the cantilever sections abut a key extending transversly through the slot to protrude from the shaft and the key is received in keyways formed in the gear diametrically of each other and opening into a cylindrical aperture. The latter is sized to receive the inner end portion of the shaft with a press fit with end walls of the keyways abutting the protruding key to locate the shaft axially within the gear. The width of the slot separating the cantilever sections of the shaft is slightly greater than the diameter of the key thereby providing clearance between the key and the cantilever sections to allow deflection of the sections during press-fitting of the shaft in the gear.

Abstract: An improved capacitive pick-off circuit is provided by utilizing an operational amplifier wherein a pick-off capacitor to be measured forms a part of a feedback circuit of the operational amplifier resulting in the gain of the operational amplifier becoming inversely proportional to the capacitance or directly proportional to the gap between the plates of the capacitor thereby providing a measure of capacitance. A differential capacitive pick-off circuit is implemented by using a pair of operational amplifiers wherein feedback circuits controlling the gain of the operational amplifiers include pick-off capacitors to be measured and a third differential amplifier is connected to the outputs of the two operational amplifiers to provide a signal representing the difference in capacitance between the two pick-off capacitors.

Abstract: An improved capacitive pick-off circuit is provided by utilizing a reference current generator to apply a square wave to a pick-off capacitor and the resulting voltage across the capacitor is then applied to a fixed capacitor. The resulting fixed capacitor current then provides a measure of the capacitance of the pick-off capacitor. A differential capacitive pick-off circuit is provided by applying the reference current to each pick-off capacitor and providing a fixed capacitor for each of the pick-off capacitors. The resulting fixed capacitor currents are combined and the resulting differential current is used as a measure of the difference in capacitance or the difference in the gaps between the plates of the capacitors.

Abstract: In a dynamoelectric machine having an exciter assembly mounted on a rotating shaft including: rectifiers for rectifying AC exciter current into a DC field current; a hub secured to the shaft; and a number of rectifier mounting plates attached to the hub, each plate having apertures through which individual rectifiers are mounted, the cooling of the exciter assembly and the rectifier diodes is facilitated by an oil spray impinging directly on the rectifier diodes and mounting plates wherein the cooling is enhanced and sludge build-up on the inner surface of the hub is reduced by providing coolant passageways in the rectifier mounting plates that allow the oil to pass through the plates.

Abstract: In a synchronous generator-motor, having both its main armature windings and exciter winding located on the stator and both the main field winding and the exciter armature windings including a rectifier for providing DC current to the main field located on the rotor and also including a voltage regulator responsive to the main armature voltage for regulating the current applied to the exciter field; the effects of transient currents in the main field windings resulting from load removal during the generator mode of operation and the voltages induced during motor start-up are substantially reduced by utilizing a resistive circuit operatively controlled by a transistor switching network that is in turn responsive to the exciter voltage and the induced voltage in the main field windings.

Abstract: A snap-fit fastening system for use in attaching a member to an electric motor utilizes stator through-bolts with specially formed heads and the member includes a plurality of slots formed in a pattern similar to the pattern in which the through-bolt holes of the stator laminates are arranged, but with the slots extending radially relative to the central axis of the stator and being offset laterally relative to the associated holes. An annular flange integrally formed with each bolt intermediate its ends seats on the top laminate to confine deflection of the upper end of the bolt to movement in a generally radial direction. Bullet-shaped extensions integrally formed with the upper ends of the bolts telescoped into the slots so a lip formed in each extension snap-fits the member onto the bolts, the lips overlapping the edges of the slots to lock the member on the through-bolts.

Abstract: Direct readings of the timing angle and duration of the fuel injection of a diesel engine along with the engine speed are provided by an electronic test instrument that converts the duration of the timing advance and the duration of one engine revolution into electrical pulses of corresponding width. Both these pulse widths are then converted to corresponding electrical quantities and the quantity which corresponds to the timing angle is divided by the quantity which corresponds to one engine revolution to produce an indication of timing angle, or alternatively a constant reference quantity is divided by the quantity which corresponds to the engine revolution, thus providing an indication the engine speed.

Abstract: A double suction, high-speed centrifugal pump includes an impeller with shrouds formed integrally with opposite sides thereof. The impeller is splined on a rotatable shaft within a chamber in a housing. Sealing rings are fixed within the chamber and axially facing sealing surfaces and walls are formed in the shrouds and sealing rings respectively to help keep liquid from leaking from the impeller discharge and back to the inlet of the impeller. Means are provided for adjusting the axial distance between each of the sealing walls of the two shrouds and the center of the impeller chamber. Also, means are provided for locating the impeller axially within the impeller chamber to precisely position the sealing surfaces with respect to the sealing walls.

Abstract: A hermetic refrigerant compressor includes an electric motor mounted within a sealed housing with a crankshaft extending vertically from the motor to connect with a plurality of radially disposed compressor pistons. The lower end portion of the crankshaft extends into a sump of lubricant collected in the lower end of the housing and first and second stage pumping means are formed in the lower end of the housing to pump lubricant to upper and lower bearings which support the crankshaft within the housing. A vent communicates with the inlet to the first stage pumping means for venting flashed refrigerant gases from the system before the lubricant enters the first stage pumping means. In addition, a filter may be provided for continuously cleaning some of the lubricant discharged from the first stage pumping means without interfering with the flow of lubricant from the first stage pumping means to the second stage pumping means.

Abstract: A one-piece support frame is used to support a pair of capacitor plates and a lightweight longitudinally reinforced pendulum having a paddle on one end. The paddle is positioned midway between the capacitor plates forming a pair of capacitors. Attached to the pendulum is an axle which in turn is supported between two flexures by means of jeweled pivoted bearings. The ends of the flexures are rigidly secured to the support frame, and a desired pressure of the bearings against the axle is maintained by means of adjustment screws. Also attached to the pendulum is a torque coil which interacts with a magnetic assembly, secured to the support frame, to restore the paddle to the midpoint between the capacitor plates when the pendulum has been subjected to an acceleration force.

Abstract: In order to provide a substantially error free biasing and scaling circuit for transducer signals, an operational amplifier and a field effect transistor are used in combination with a DC voltage source to bias and scale the transducer signal.

Abstract: In order to enhance the reliability of a built-in test system, a confidence check circuit is connected to the logic and condition sensors of the system in order to test for the proper system operation. The confidence check circuit includes a ring counter which sequentially applies check signals of sufficient magnitude to each of the condition sensors to simulate a condition exceeding acceptable system operation limits resulting in the activation of an appropriate failure indicator associated with the built-in test system if the system is operating properly. A check signal is applied to each condition sensor and verification logic within the confidence check circuit responds to the activation of the correct failure indicator by incrementing the ring counter so as to generate a check signal for the next condition sensor in the confidence check sequence.

Abstract: A hermetic refrigerant compressor includes an electric motor mounted within a sealed housing with a crankshaft extending vertically from the motor to connect with a plurality of compressor pistons. The lower end portion of the crankshaft extends into a sump of lubricant in the housing and a pump is formed in the lower end of the crankshaft to pump lubricant through a discharge conduit to an annular chamber located within an upper bearing support for the crankshaft. The discharge conduit is offset from the central axis of the crankshaft and a diametrical cross-bore including first and second radial segments communicates with the annular chamber, the cross-bore intersecting the upper end of the discharge conduit. From the discharge conduit, one segment of the cross-bore is longer than the other so that lubricant is slung radially outward through the shorter length segment into the annular chamber.

Abstract: A burner control system includes a pump for supplying pressurized fuel through a fuel line and a signal-responsive flow valve to a burner nozzle. Also in the system is an ignition control circuit which includes an igniter operable in response to a first signal in the circuit to ignite the fuel. A flame-detecting cell in the circuit causes the termination of the first signal so as to deactivate the igniter when combustion occurs. A second or auxiliary circuit operatively connected to the ignition control circuit includes a first switch responsive to the first signal in the ignition control circuit to cause a second signal to be transmitted to the flow valve for opening the valve to allow pressurized fuel to flow to the nozzle. A second switch in the second circuit serves as an alternate circuit for transmitting the second signal to the flow valve.