Abstract: An aircraft taxi drive system includes a motor that is configured to transfer power to an aircraft wheel via a drive chain, such that the motor rotates the aircraft wheel via the drive chain. In some examples, the drive chain is movable between first and second positions. In the first position, the drive chain, such as an exterior surface of the drive chain, is engaged with a driven sprocket that is mechanically connected to an aircraft wheel. In the second position, the drive chain is disengaged from the driven sprocket.

Abstract: An aircraft taxi drive system includes a motor that is configured to transfer power to an aircraft wheel via a drive chain, such that the motor rotates the aircraft wheel via the drive chain. In some examples, the drive chain is movable between first and second positions. In the first position, the drive chain, such as an exterior surface of the drive chain, is engaged with a driven sprocket that is mechanically connected to an aircraft wheel. In the second position, the drive chain is disengaged from the driven sprocket.

Abstract: A valve actuator is provided for use in conjunction with a drive motor and a valve. In one embodiment, the valve actuator includes a housing assembly, a first power screw rotatably mounted in the housing assembly and configured to be rotated by the drive motor, a first rack translatably mounted in the housing assembly, and a pinion rotatably mounted in the housing assembly and mechanically linked to the valve. The first rack is threadably coupled to the first power screw and is configured to move linearly as the first power screw rotates. The pinion engages the first rack and is configured to rotate as the first rack moves linearly to move the valve to a desired position.

Abstract: A linear actuator includes a thrust bearing that is integral to the actuation member. The actuator includes a translation member and an actuation member. The actuation member is responsive to a drive force to rotate. The translation member is configured to translate in response to actuation member. The thrust bearing is coupled to the actuation member and includes an inner race, an outer race, and a plurality of balls. The thrust bearing is configured as a zero lead ballscrew, with the inner race integrally formed on the actuation member, and the plurality of balls disposed between the inner and outer races.

Abstract: A linear actuator includes a thrust bearing that is integral to the actuation member. The actuator includes a translation member and an actuation member. The actuation member is responsive to a drive force to rotate. The translation member is configured to translate in response to actuation member. The thrust bearing is coupled to the actuation member and includes an inner race, an outer race, and a plurality of balls. The thrust bearing is configured as a zero lead ballscrew, with the inner race integrally formed on the actuation member, and the plurality of balls disposed between the inner and outer races.

Abstract: A valve actuator is provided for use in conjunction with a drive motor and a valve. In one embodiment, the valve actuator includes a housing assembly, a first power screw rotatably mounted in the housing assembly and configured to be rotated by the drive motor, a first rack translatably mounted in the housing assembly, and a pinion rotatably mounted in the housing assembly and mechanically linked to the valve. The first rack is threadably coupled to the first power screw and is configured to move linearly as the first power screw rotates. The pinion engages the first rack and is configured to rotate as the first rack moves linearly to move the valve to a desired position.

Abstract: A drive shaft is configured to be disposed between a drive mechanism and a plurality of driven mechanisms and to transfer a drive torque generated by the drive mechanism to one of the plurality of driven mechanisms. The drive shaft includes a first shaft section and a second shaft section. The first shaft section has a first outer diameter, and is dimensioned to be disposed within the drive mechanism, within one of the plurality of driven mechanisms, or simultaneously within the drive mechanism and one of the plurality of driven mechanisms. The first shaft section is also configured to at least selectively engage, and thereby at least selectively receive the drive torque generated in, the drive mechanism. The second shaft section is coupled to the first shaft section and has a second outer diameter that is less than the first outer diameter. The second shaft section is dimensioned to be disposed within either the drive mechanism or one of the plurality of driven mechanisms.

Abstract: A turbofan gas turbine propulsion engine includes a system to transfer power from the low pressure turbine to the high pressure turbine and/or extract additional load from the low pressure turbine during certain turbofan engine operational conditions. The systems include a hydrostatic power transfer system that includes a hydraulic pump and a hydraulic motor coupled to the low pressure and high pressure turbine, respectively. The systems additionally include a mechanical and electrical load shifting/loading sharing systems that use clutches and gear assemblies to share and/or shift load between the turbines.

Abstract: A turbofan gas turbine propulsion engine includes a multi-speed transmission between the high pressure and low pressure turbines and associated high pressure and low pressure starter-generators. The multi-speed transmission reduces the operating speed range from the low pressure turbine to its associated starter-generator, and is configurable to allow the starter-generator associated with the low pressure turbine to supply starting torque to the engine.

Abstract: An actuator that at least inhibits the deleterious effects of corrosive fluids, such as seawater, does not rely on relatively expensive materials, and is capable of operation and relatively high pressures includes two sealed buffer chambers. One buffer chamber is supplied with a buffer fluid, and the other buffer chamber is maintained at a vacuum pressure. The buffer fluid in the first buffer chamber helps remove any residual corrosive fluid that may remain on the actuator translation member as it moves into the actuator housing, and any fluid that leaks into the second chamber will boil as a result of the vacuum pressure therein.

Abstract: A lubrication system for supplying lubricants between two environments is provided. The first environment is disposed within a first housing and the second environment is disposed within a second housing having a supply opening and an exhaust opening. The system includes a lubricant supply tube disposed within the supply opening and configured to supply lubricant from the first environment to the second environment. The system also includes a receptacle disposed within the second housing and configured to receive lubricant supplied from the supply tube and to hold a predetermined volume of the lubricant. A check valve is disposed within the second housing and is in fluid communication with the exhaust opening. The check valve is configured to receive overflow lubricant from the receptacle, if the lubricant exceeds the predetermined volume and to provide a seal between the first and second environments in response to a pressure differential therebetween.

Abstract: An actuator that at least inhibits the deleterious effects of corrosive fluids, such as seawater, does not rely on relatively expensive materials, and is capable of operation and relatively high pressures includes two sealed buffer chambers. One buffer chamber is supplied with a buffer fluid, and the other buffer chamber is maintained at a vacuum pressure. The buffer fluid in the first buffer chamber helps remove any residual corrosive fluid that may remain on the actuator translation member as it moves into the actuator housing, and any fluid that leaks into the second chamber will boil as a result of the vacuum pressure therein.

Abstract: A seal pressure vent system for a waterjet propulsion apparatus including a water intake section and a pumping unit. The pumping unit is designed such that in operation the seal pressure vent system provides a fluidic path for the flow of high pressure water away from a lip seal assembly toward a near ambient pressure region. The seal vent system includes a plurality of fluid passageways formed in a stator structure in conjunction with a water barrier ring, a tail cone including an extended flange, or a modified stator web structure.

Abstract: A seal pressure vent system for a waterjet propulsion apparatus including a water intake section and a pumping unit. The pumping unit is designed such that in operation the seal pressure vent system provides a fluidic path for the flow of high pressure water away from a lip seal assembly toward a near ambient pressure region. The seal vent system includes a plurality of fluid passageways formed in a stator structure in conjunction with a water barrier ring, a tail cone including an extended flange, or a modified stator web structure.

Abstract: A relatively small, lightweight valve actuator assembly that can withstand relatively high levels of vibration and shock includes a motor, a position sensor, and a drive belt mounted on an actuator housing assembly. The position sensor is preferably disposed within a sensor housing that is mounted on a side of the actuator housing assembly. As a result, the overall center-of-gravity (CG) and weight of the actuator assembly is significantly reduced, as is the overall size envelope.

Abstract: Methods and apparatus are provided for monitoring an aircraft accessory. The apparatus comprises a processor associated with said aircraft accessory, a transducer coupled to said processor and operable to produce parametric data relating to said aircraft accessory and a memory coupled to said processor having baseline parametric data residing therein, wherein said baseline parametric data comprises the parametric data obtained during an acceptance test procedure. The method comprises installing a transducer configured to produce parametric data relating to said aircraft accessory, coupling said transducer to a processor associated with said aircraft accessory, coupling said processor to a memory associated with said aircraft accessory, recording baseline parametric data relating to said aircraft accessory in said memory during an acceptance test procedure for said aircraft accessory.

Abstract: An air turbine starter is provided that includes a check valve assembly. The check valve assembly comprises a valve body, a valve seat and a valve element. The valve body includes an inlet port, an outlet port, and a flow passage extending therebetween. The valve seat is coupled to the valve body, extends at least partially into the flow passage and has an opening therethrough. The valve element is disposed within the flow passage between the valve seat and the valve body outlet port. The valve element is also configured to translate axially between an open position and a closed position in response to a pressure differential between the inlet and outlet ports.

Abstract: An air turbine starter is provided that includes a check valve assembly for placement between a first environment, at least a portion of which is at a first pressure (P1), and a second environment, at least a portion of which is at a second pressure (P2), wherein the difference between the first and second pressures generate a pressure force (Fp). The check valve assembly comprises a valve element disposed between the valve seat and the valve body, the valve element capable of being acted upon by a gravitational force (Fw), a viscous force of the fluid to be communicated between the gearbox assembly and the starter housing (Fv), a buoyancy force of the valve element (Fb), and the pressure force on the valve element (Fp), the valve element further configured to translate axially to a closed position when P2<P1 and Fw<Fv+Fb+Fp.

Abstract: A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.

Abstract: A flight control actuation system comprises a controller, electromechanical actuator and a pneumatic actuator. During normal operation, only the electromechanical actuator is needed to operate a flight control surface. When the electromechanical actuator load level exceeds 40 amps positive, the controller activates the pneumatic actuator to offset electromechanical actuator loads to assist the manipulation of flight control surfaces. The assistance from the pneumatic load assist actuator enables the use of an electromechanical actuator that is smaller in size and mass, requires less power, needs less cooling processes, achieves high output forces and adapts to electrical current variations. The flight control actuation system is adapted for aircraft, spacecraft, missiles, and other flight vehicles, especially flight vehicles that are large in size and travel at high velocities.