Abstract: A seal assembly for a turbomachine. The turbomachine includes a rotating shaft extending along a centerline and a fixed housing positioned exterior to the rotating shaft in a radial direction relative to the centerline. The seal assembly includes a sump housing at least partially defining a bearing compartment for holding a cooling lubricant. The seal assembly further includes a bearing supporting the rotating shaft. In addition, the seal assembly also includes a sump seal at least partially defining the bearing compartment. A pressurized housing of the seal assembly is positioned exterior to the sump housing and defines a pressurized compartment to at least partially enclose the sump housing. Further, a non-contacting carbon seal is positioned between the rotating shaft and the fixed housing to at least partially define the pressurized compartment to enclose the sump housing.

Abstract: A seal assembly for a turbomachine. The turbomachine includes a rotating shaft extending along a centerline and a fixed housing positioned exterior to the rotating shaft in a radial direction relative to the centerline. The seal assembly includes a sump housing at least partially defining a bearing compartment for holding a cooling lubricant. The seal assembly further includes a bearing supporting the rotating shaft. In addition, the seal assembly also includes a sump seal at least partially defining the bearing compartment. A pressurized housing of the seal assembly is positioned exterior to the sump housing and defines a pressurized compartment to at least partially enclose the sump housing. Further, a non-contacting carbon seal is positioned between the rotating shaft and the fixed housing to at least partially define the pressurized compartment to enclose the sump housing.

Abstract: A gas turbine engine comprises a fan, a compressor, a turbine having first stage blades and second stage blades, the first stage blades rotates in a first direction and the second stage blades rotates in a second direction opposite the first direction. The first stage blades are directly adjacent to one another, a drive in operable input connection with the fan and in operable output connection with the first stage blades and the second stage blades, the first stage blades and the second stage blades driving the fan through the drive.

Abstract: A gas turbine engine comprises a fan, a compressor, a turbine having first stage blades and second stage blades, the first stage blades rotates in a first direction and the second stage blades rotates in a second direction opposite the first direction. The first stage blades are directly adjacent to one another, a drive in operable input connection with the fan and in operable output connection with the first stage blades and the second stage blades, the first stage blades and the second stage blades driving the fan through the drive.

Abstract: A rotary hydraulic actuator includes a housing defining a chamber, a first boss, and a port block with a bore communicating with the chamber. The port block includes rotor supply and drain ports communicating with the bore, and a stator port communicating with the chamber through a stator hole in the boss. A rotor mounted in the internal chamber includes: a body with a laterally-extending arm; a first stub shaft received in the bore, the first stub shaft including base slots passing laterally therethrough; a first rotor port disposed in the arm in communication with the internal chamber, and oriented in a tangential direction relative to an axis of rotation; and internal passages which interconnect the rotor base slots and the first rotor port. Passages in the port block communicate with the bore and interconnect the rotor supply and drain ports at a first angular position of the rotor.

Abstract: A dual fuel propulsion system comprising a gas turbine engine configured to generate a propulsive thrust using a cryogenic liquid fuel.

Abstract: A precooler for cooling compressor bleed air for an environmental control system includes a heat exchanger in fluid communication with a source of cooling air and operable for cooling the bleed air. A variable bypass valve between a bleed air source and environmental control system is operable for bypassing at least a portion of the compressor bleed air around the heat exchanger. The cooling air may be a portion of fan air modulated by a variable fan air valve. The bleed air source may be selectable between the low pressure bleed air source and a high pressure bleed air source. One method includes flowing the compressor bleed air from a single low pressure source only and increasing thrust sufficiently to meet a minimum level of pressure of the bleed air during one engine out aircraft operating condition during approach or loitering.

Abstract: Spaced apart counter-rotatable forward and aft rows of forward and aft propellers are mounted on forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators on the frames are operable for controlling pitch of the propellers. A hydraulic fluid supply outboard of the frames is connected to forward and aft rotary unions which are operable for transferring hydraulic fluid between forward and aft union stators to forward and aft union rotors mounted within the forward and aft rotary unions. The forward union rotor is operable to transfer the hydraulic fluid from the forward rotary union to the aft pitch change actuators and the aft union rotor is operable to transfer the hydraulic fluid from the aft rotary unions to the forward pitch change actuators. The forward and aft rotatable frames counter-rotatably mounted on a structural frame located forward or aft of the propellers.

Abstract: Axially spaced apart counter-rotatable forward and aft rows of forward and aft propellers mounted on forward and aft rotatable frames includes a flowpath passing through the forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators mounted on the aft rotatable frames are connected to and operable for controlling and setting pitch of the aft propellers. The pitch change actuators are mounted radially inwardly of the flowpath in a one to one ratio with forward and aft rotatable struts extending radially across the flowpath. One or more rotatable shafts extend through one or more of the rotatable struts and connect one or more of the pitch change actuators to one or more of the propellers. The pitch change actuators may be ganged together by unison rings having ring teeth engaging gear teeth on gears connected to the pitch change actuators or connected to the rotatable shafts.

Abstract: A rotary hydraulic actuator includes a housing defining a chamber, a first boss, and a port block with a bore communicating with the chamber. The port block includes rotor supply and drain ports communicating with the bore, and a stator port communicating with the chamber through a stator hole in the boss. A rotor mounted in the internal chamber includes: a body with a laterally-extending arm; a first stub shaft received in the bore, the first stub shaft including base slots passing laterally therethrough; a first rotor port disposed in the arm in communication with the internal chamber, and oriented in a tangential direction relative to an axis of rotation; and internal passages which interconnect the rotor base slots and the first rotor port. Passages in the port block communicate with the bore and interconnect the rotor supply and drain ports at a first angular position of the rotor.

Abstract: A precooler for cooling compressor bleed air for an environmental control system includes a heat exchanger in fluid communication with a source of cooling air and operable for cooling the bleed air. A variable bypass valve between a bleed air source and environmental control system is operable for bypassing at least a portion of the compressor bleed air around the heat exchanger. The cooling air may be a portion of fan air modulated by a variable fan air valve. The bleed air source may be selectable between the low pressure bleed air source and a high pressure bleed air source. One method includes flowing the compressor bleed air from a single low pressure source only and increasing thrust sufficiently to meet a minimum level of pressure of the bleed air during one engine out aircraft operating condition during approach or loitering.

Abstract: Axially spaced apart counter-rotatable forward and aft rows of forward and aft propellers mounted on forward and aft rotatable frames includes a flowpath passing through the forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators mounted on the aft rotatable frames are connected to and operable for controlling and setting pitch of the aft propellers. The pitch change actuators are mounted radially inwardly of the flowpath in a one to one ratio with forward and aft rotatable struts extending radially across the flowpath. One or more rotatable shafts extend through one or more of the rotatable struts and connect one or more of the pitch change actuators to one or more of the propellers. The pitch change actuators may be ganged together by unison rings having ring teeth engaging gear teeth on gears connected to the pitch change actuators or connected to the rotatable shafts.

Abstract: Spaced apart counter-rotatable forward and aft rows of forward and aft propellers are mounted on forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators on the frames are operable for controlling pitch of the propellers. A hydraulic fluid supply outboard of the frames is connected to forward and aft rotary unions which are operable for transferring hydraulic fluid between forward and aft union stators to forward and aft union rotors mounted within the forward and aft rotary unions. The forward union rotor is operable to transfer the hydraulic fluid from the forward rotary union to the aft pitch change actuators and the aft union rotor is operable to transfer the hydraulic fluid from the aft rotary unions to the forward pitch change actuators. The forward and aft rotatable frames counter-rotatably mounted on a structural frame located forward or aft of the propellers.