Centrifugal compressor-turbine back-to-back; inrunner axial compressor; and conformed integrated fuel cell system

Abstract

A hydrogen fuel cell electric engine 50 comprising a centrifugal compressor and a turbine rotatably mounted, back-to-back on a common shaft with one or more fuel cells 60A, 60B arranged around an outs

Description

[0001] The present disclosure relates to electrically-powered turbomachine assemblies and more particularly to hydrogen fuel cell electric engine systems for use with vehicles such as aircraft and will be described in connection with such utility, although other utilities are contemplated.

[0002] This section provides background information related to the present disclosure which is not necessarily prior art. This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all its features.

[0003] Exhaust emissions from transport vehicles are a significant contributor to climate change. Conventional fossil-fuel-powered aircraft engines release CO: emissions. Also, fossil-fuel-powered aircraft emissions include non-CO2 effects due to nitrogen oxide (NOx), vapor trails, and cloud formation triggered by the altitude at which aircraft operate. These non-CO2 effects are believed to contribute twice as much to global warming as aircraft CO2 and are estimated to be responsible for two-thirds of aviation’s climate impact. Additionally, the high-speed exhaust gasses of conventional fossil-fuel-powered aircraft engines contribute significantly to the extremely large noise footprint of commercial and military aircraft, particularly in densely populated areas.

[0004] Rechargeable battery-powered terrestrial vehicles, i.e., “EVs”, are slowly replacing conventional fossil-fuel-powered terrestrial vehicles. However, the weight of batteries and limited energy storage of batteries makes rechargeable battery-powered aircraft generally impractical.

[0005] Hydrogen fuel cells (FCs) offer an attractive alternative to fossil-fuel-burning engines. Hydrogen FC tanks may be quickly filled and store significant energy, and other than the relatively small amount of unreacted hydrogen gas, the reaction output exhausted from hydrogen FCs comprises essentially only water.

[0006] In our prior US Published Application No. US 2021 / 0151783, we describe an integrated hydrogen FC-powered electric engine system that can be utilized, for example, in a turboprop or turbofan system, to provide a streamlined, light weight, power dense and efficient system. Referring to Fig. 1, the integrated hydrogen-electric engine system 1 includes an elongated shaft 10 that defines a longitudinal axis “L” and extends through the entire powertrain of integrated hydrogen-electric engine system 1 to function as a common shaft for the various components of the powertrain. Elongated shaft 10 supports propulsor 14 (e.g., a fan or propeller), a multi-stage air compressor system 12, 12a, 12b, a fuel pump 22 in fluid communication with a fuel source (e.g., liquid hydrogen - LH?), a heat exchanger 24 in fluid communication with air compressor system 12, 12a, 12b, a FC stack 26 in fluid communication with heat exchanger 24, and a motor assembly 30 disposed in electrical communication with FC stack 26.

[0007] Air compressor system 12, 12a, 12b of integrated hydrogen-electric engine system 1 includes an air inlet portion 12a at a distal end thereof and a compressor portion 12b that is disposed proximally of air inlet portion 12a for uninterrupted, axial delivery of air flow in the proximal direction. Compressor portion 12b supports a plurality of longitudinally spaced-apart rotatable compressor wheels 16 (e.g., multi-stage) that rotate in response to rotation of elongated shaft 10 for compressing air received through air inlet portion 12a for pushing the compressed air to a FC stack 26 for conversion to electrical energy. As can be appreciated, the number of compressor wheels 16 and / or diameter, longitudinal spacing, and / or configuration thereof can be modified as desired to change the amount of air supply, and the higher the power, the bigger the propulsor 14. These compressor wheels 16 can be implemented as axial or centrifugal compressor stages. Further, the compressor can have one or more bypass valves and / or wastegates 17 to regulate the pressure and flow of the air that enters the downstream FC, as well as to manage the cold air supply to any auxiliary heat exchangers in the system.

[0008] Compressor 12b optionally can be mechanically coupled to elongated shaft 10 via a gearbox 18 to change (increase and / or decrease) compressor turbine rotations per minute (RPM) and to change air flow to FC stack 26. For instance, gearbox 18 can be configured to enable the air flow, or portions thereof, to be exhausted for controlling a rate of air flow through the FC stack 26, and thus, the output power.

[0009] Integrated hydrogen-electric engine system 1 further includes a gas management system such as a heat exchanger 24 disposed concentrically about elongated shaft 10 and configured to control thermal and / or humidity characteristics of the compressed air from air compressor system 12 for conditioning the compressed air before entering FC stack 26. Integrated hydrogen-electric engine system 1 further also includes a fuel source 20 of cryogenic fuel (e.g., liquid hydrogen— LH2, or cold hydrogen gas) that is operatively coupled to heat exchanger 24 via a pump 22 configured to pump the fuel from fuel source 20 to heat exchanger 24 for conditioning. In particular, the LH2 fuel, while in the heat exchanger 24, becomes gasified because of heating (e.g., LH2 converts to hydrogen gas - H2) taking heat out of the system. The hydrogen gas is then heated in the heat exchanger 24 to a working temperature of the FC stack 26 which also takes heat out of the compressed air, which results in a control of flow through the heat exchanger 24. In one embodiment, a heater 39 can be coupled to or included with heat exchanger 24 to increase heat as necessary, for instance, when running under a low power regime. Integrated hydrogenelectric engine system 1 also may include one or more external radiators 19 for facilitating air flow and adding, for instance additional cooling. Additionally, and / or alternatively, motor assembly 30 can be coupled to heat exchanger 24 for looping in the cooling / heating loops from motor assembly 30 as necessary. Such heating / cooling control can be managed, for instance, via controller 200 of integrated hydrogen-electric engine system 1. In one embodiment, fuel source 20 can be disposed in fluid communication with motor assembly 30 or any other suitable component to facilitate cooling of such components. Motor assembly 30 can include any number of fuel cell modules configured to march the power of the motors and the inverters 29.

[0010] Pump 22 can be coaxially supported on elongated shaft 10 for actuation thereof in response to rotation of elongated shaft 10. Heat exchanger 24 is configured to cool the compressed air received from air compressor system 12, 12a, 12b with the assistance of the pumped liquid hydrogen.

[0011] While existing hydrogen FC-powered electric engine systems, such as those disclosed in our US Published Application 2021 / 0151783, and as illustrated in Fig. 1, discussed above, advantageously may be mounted in the fuselage of an aircraft or a large nacelle mounted to an aircraft, existing hydrogen FCs can be too large and awkwardly shaped for packaging in conventional aircraft nacelles. In particular, the long shaft employed with existing hydrogen FC-powered engine systems as above described is too long to fit within conventional aircraft nacelles, which are aerodynamic pods commonly mounted to the wing or fuselage of an aircraft. As a result, conventional hydrogen FC electric engine architectures do not provide sufficient power density (W / m3) to replace conventional fossil-fuel-powered turbine engines.

[0012] In order to overcome the aforesaid and other problems of the prior art, in accordance with Aspect A of the present disclosure, we provide an integrated hydrogen FC electric engine system for aircraft comprising a centrifugal compressor and a turbine rotatably mounted, back-to-back on a common shaft, with the FCs arranged around an outside of the rotatably mounted centrifugal compressor and the rotatably mounted turbine.

[0013] In one embodiment of Aspect A, the FC is arranged so that the FC cathodes are positioned facing inwardly towards and closer to the common shaft while the FC anodes are positioned facing outwardly, i.e., facing away from the common shaft.

[0014] In accordance with another embodiment of Aspect A, the centrifugal compressor shares a common shaft with an exhaust turbine. Both the centrifugal compressor and the exhaust turbine have a compact length, while providing adequate airflow and pressure to the FC cathode. In order to minimize size and maximize airflow efficiencies, FCs are arranged such that their cathodes are in close proximity to the compressor outlet and the turbine inlet. Airflow from the rotatably mounted centrifugal compressor may be directed through the cathode to the turbine.

[0015] In this embodiment, an anode tail oxidizer combusts anode exhaust hydrogen with cathode exhaust air and delivers resulting exhaust to the turbine.

[0016] In another embodiment of Aspect A, the FC comprises a single continuous radially symmetric FC.

[0017] In yet another embodiment, a radial array of roughly rectangular FC stacks is arranged around the central shaft.

[0018] The result is an axially compact layout, which allows the length of the rotating elements to be minimized. This reduces weight associated with long shafts and multiple bearing supports of prior art integrated FC-powered electric engine system such as illustrated in Fig. 1, as above described, and also makes it possible to package our integrated hydrogen FC-powered electric engine within a conventional aircraft nacelle.

[0019] In yet another embodiment of Aspect A, the hydrogen FC-powered electric engine includes annular ducting configured to provide cooling air to the FCs. The annular duct may have an air inlet configured for uninterrupted axial delivery of airflow to the compressor and exhaust of spent air from the turbine via an air exhaust outlet. In such an embodiment, the annular ducting may be exposed to ram pressurization of a moving vehicle such as an aircraft or by a fan, which in a preferred embodiment is concentric with the compression-turbine (CT) shaft.

[0020] In one embodiment of Aspect A, when a fan is provided the fan has a larger diameter and lower rotational speed than the CT shaft. In such case, the fan axis may be connected to the CT shaft via a gearbox, preferably via planetary gearing.

[0021] In yet another embodiment of Aspect A, the fan is driven from its outside rim. In such embodiment, the fan need not be in contact with the CT shaft and may have its own bearings for support.

[0022] In one embodiment of Aspect A, cooling air after passing through the FC is warmed, and the warmed air is passed through a cooling-air turbine to recover some of the heat energy in the form of mechanical power.

[0023] In yet another embodiment of Aspect A, the common shaft is extended on either end to connect to electric motors, generators, and gearboxes and / or propulsion systems such as a propellor.

[0024] More particularly, in accordance with one embodiment of Aspect A, there is provided an integrated hydrogen FC electric engine comprising: a centrifugal compressor and a turbine rotatably mounted, back-to-back on a common shaft; and one or more FCs arranged around an outside of the rotatably mounted centrifugal compressor and the rotatably mounted turbine.

[0025] In one embodiment of Aspect A, the one or more FCs are arranged with their cathode sides closer to the common shaft.

[0026] In one aspect airflow from the rotatably mounted centrifugal compressor is directed through the cathode to the turbine.

[0027] In another embodiment of Aspect A, the rotatably mounted compressor and the rotatably mounted turbine are housed within an annular duct having an air inlet configured for uninterrupted axial delivery of airflow to the compressor and exhaust of spent air from the turbine via an air exhaust outlet.

[0028] In yet another embodiment of Aspect A, one or more FCs comprise a single, continuous radially-symmetrically shaped FC.

[0029] In another embodiment of Aspect A, one or more FCs comprise a plurality of FCs arranged in a radial array of FCs around the central shaft.

[0030] In yet another embodiment of Aspect A, one or more FCs comprise a plurality of FCs in the form of a radial array of substantially rectangularly shaped FC stacks arranged around the central shaft.

[0031] In another embodiment of Aspect A, the integrated hydrogen FC electric engine further comprising one or more fans for moving cooling air through the one or more FCs.

[0032] In one embodiment of Aspect A, the one or more fans are configured to be driven by the central shaft. In such aspect, one or more shafts may be configured to be driven by the central shaft through a gearbox driven by the central shaft. In such aspect the gearbox preferably comprises planetary gears.

[0033] In another embodiment of Aspect A, one or more fans preferably are configured to be driven from their outside rims. In such aspect, one or more fans preferably are configured to be supported on bearings or rollers in contact with the fans’ outer rims.

[0034] In accordance with Aspect B of the present disclosure, we provide electrically-powered turbomachine assemblies, and more particularly hydrogen FC electric systems comprising: a housing; a rotating shaft; an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft; an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor fixed to the rotating shaft; and a turbine including a turbine stator fixed to the housing and a turbine rotor fixed to the rotating shaft. In such embodiment the electrically-powered turbomachine assembly may include one or more fuel cells (FCs) arranged around an outside of the electrically-powered turbomachine assembly, wherein anode exhaust from the one or more FCs is configured to be passed to the turbine.

[0035] In one embodiment of Aspect B, an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor.

[0036] In another embodiment of Aspect B, the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft.

[0037] In another embodiment of Aspect B, one or more of the compressor stator and / or the one or more electric motor stators and / or the one or more of the turbine stators is / are configured for carrying an electric current.

[0038] In one embodiment of Aspect B, one or more of the compressor stators and / or the one or more of the turbine stators and / or one or more of the electric motor stators has / have a passage or passages configured to accommodate an electrical conduit within the stator. In another embodiment the one or more of the compressor stators and / or the turbine stators preferably is / are formed of an electrically conductive material and is configured to carry an electrical current.

[0039] In another embodiment of Aspect B, one or more of the compressor stators and / or turbine stators and / or the one or more of the electric motor stators has / have a passage or passages configured to carry a fluid. In such embodiment the fluid may comprise a thermal transfer fluid, or a lubricant. In the case where the fluid is a lubricant, in one embodiment the lubricant may form a fluid dynamic bearing for supporting the rotating shaft.

[0040] In another embodiment of Aspect B, one or more of the motor stators include cooling fins.

[0041] In a further embodiment of Aspect B, the rotating shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another.

[0042] According to yet another embodiment of Aspect B, the present disclosure provides an FC-powered vehicle comprising the electrically-powered turbomachine assembly as above described, and one or more FCs and / or current inverters arranged outside of the electrically-powered turbomachine assembly.

[0043] In another embodiment of Aspect B, the air compressors are configured to deliver air to a cathode side of the one or more FCs.

[0044] In yet another embodiment of Aspect B, anode exhaust from the FCs is passed to the turbine.

[0045] In a further embodiment of Aspect B, the electric motor stators include fins configured to be cooled by airflow from the compressors.

[0046] In still yet another embodiment, the system includes one or more inverters having cooling fins configured to extend into the housing and into cooling airflow from the compressors.

[0047] According to Aspect C, we provide a compact FC electrically-powered turbomachine assembly in which an electric motor, an air compressor system, and a turbine system are arranged around a central rotating shaft, in a housing. The compressor stators and the turbine stators are affixed to the housing, and the electric motor stators are affixed to the compressor stators. The compressor blades and turbine blades, and the electric motor cores are all affixed to the rotating shaft, and the electric motors are located within the compressor system and the turbine system. One or more FCs and inverters are arranged to the exterior of the housing resulting in an extremely compact system that can be fitted into a conventional fossil-fuel-powered aircraft nacelle. This permits us to retrofit conventional fossil-fuel-powered aircraft, replacing the existing fossil-fuel-powered turbine engines with hydrogen FC electric engines.

[0048] In one embodiment of Aspect C, the integrated hydrogen-electric engine system includes a fixed central shaft. Along the shaft, fixed components include motor stators, turbo compressor stator vanes, and expansion turbine stator vanes. The turbo compressor stator vanes are supported by the housing. The motor stators are supported by the central shaft which is in turn supported by stator vanes. The stator vanes outer edges are connected to a tubular housing which acts as both mechanical support and an aerodynamic duct. Each motor has a rotating outer shell, or rotor. Mounted to the shell of the motor(s) are compressor or turbine blades . Each rotating shell is supported by one or more bearings, preferably two, to maintain the alignment of the rotating machinery relative to the fixed machinery. In one embodiment, the outer shell of the motor is the stator (fixed) and the inner portion rotates.

[0049] One purpose of the compressor is to pressurize and condition air for the FCs. Air in a plenum is fed into the FC cathode side inlet. FC exhaust may then be combusted in an anode tail oxidizer (ATO) to harvest additional enthalpy to drive the turbine. Excess enthalpy in the flow after the turbine can be used to generate thrust directly through a nozzle.

[0050] Electrical power is provided to the motors via stator vanes aligned with each motor. There may be electrical conduits within the stator vanes, or the entire blade may be made of an electrically conductive material. Different blades may be connected to the phase leads of the motors. Sensors such as phase encoders may be connected via wires in electrical conduits within the stator vanes. The wiring to the motor stator coils may also pass axially along the central shaft.

[0051] The FCs are cooled using ram air, which in some flight conditions is too cold to apply to the FCs directly and may require heating. In such case, warm bleed air from turbine may be injected into and mixed with the ram air stream using injectors. In other embodiments, the bleed air could also be pulled from the compressor. In some embodiments, the ram air is assisted by a fan, which offsets the pressure drop of the ducting and allows for the duct to cool when the engine is operating while the aircraft is stationary.

[0052] Fluids for cooling or lubrication may be piped in passages within the stator vanes. A passage may enclose a fluid flow tube, or the fluid passage may be a hole connecting the inner and outer ends of the stator vanes. The fluids may be oils for lubrication of motor or rotor bearings, coolants, hydraulic or pneumatic pressure transmission. The fluids may also pass axially along the central shaft.

[0053] Air moving through the compressor may be used to heat or cool fluids moving through stator vanes. This includes motor coolant and lubrication, as well as FC coolant, pumped through the stator vanes. The internal structure of the stator vane can be designed to optimize the internal flow paths of fluids to maximize contact with the vane surface, acting as a heat exchanger. As an additional effect, fluid pumped through the stator vanes may be used to condition air flowing through the compressor before it reaches the FC cathode. If cold fluid (e.g., turbine oil) is pumped through the stator vanes (e.g., to warm lubricant from a larger reservoir to achieve desired rheometric properties), it may be used to intercool (isobaric cooling) air as it moves through the compressor. Liquid hydrogen will need to be heated and may be pumped through stator vanes to absorb heat from the vanes and gasify the LH2 before being introduced to the FC.

[0054] Passages within the central shaft may convey fluids from one location along the shaft to another. Seals and rotating couplings may enable multiple fluids to be conveyed to and from multiple locations. In particular, rotating seals may enable a coolant or lubricant to pass from the stationary central shaft to the rotating motor shells. In some cases, the fluids may be cryogenic coolants, including liquid hydrogen. This could enable superconducting motor windings. The turbine generator and compressor motors are electrically coupled, so that energy recovered from the turbine can be used to power the compressor. In one embodiment, electrical connections may be routed through the stationary central shaft.

[0055] In accordance with Aspect D of the present disclosure, we provide an electrically-powered turbomachine assembly comprising: a housing; a rotating shaft; an air compressor comprising one or more compressor stators; one or more electric motors including one or more electric motors including an electric motor stators and electric motor rotors.

[0056] In one embodiment of Aspect D, an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor.

[0057] In another embodiment of Aspect D, the electric motor core, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft.

[0058] In another embodiment of Aspect D, one or more of the compressor stator and / or the electric motor stator and / or the turbine stator is / are configured for carrying an electric current.

[0059] In one embodiment of Aspect D, one or more of the compressor stators and / or the turbine stators and / or the electric motor stators has / have a passage or passages configured to accommodate an electrical conduit within the stator. In another embodiment the one or more of the compressor stators and / or the turbine stators preferably is / are formed of an electrically conductive material and is configured to carry an electrical current.

[0060] In another embodiment of Aspect D, one or more of the compressor stators and / or turbine stators and / or the electric motor stators has / have a passage or passages configured to carry a fluid. In such embodiment the fluid may comprise a thermal transfer fluid, or a lubricant. In the case where the fluid is a lubricant, in one embodiment the lubricant may form a fluid dynamic bearing for supporting the rotating shaft.

[0061] In another embodiment of Aspect D, one or more of the motor stators include cooling fins.

[0062] In a further embodiment of Aspect D, the rotating shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another.

[0063] According to Aspect E, the present disclosure provides an FC-powered vehicle comprising the electrically-powered turbomachine assembly as above described, and one or more FCs and / or current inverters arranged outside of the electrically-powered turbine assembly.

[0064] In one embodiment of Aspect E, the air compressors are configured to deliver air to a cathode side of the one or more FCs.

[0065] In another embodiment of Aspect E, anode exhaust from the FCs is passed to the turbine.

[0066] In a further embodiment of Aspect E, the electric motor stators include fins configured to be cooled by airflow from the compressor.

[0067] In another embodiment of Aspect E, one or more of FCs are arranged around an outside of the electrically-powered turbine assembly, wherein anode exhaust from the one or more FCs is configured to be passed to the turbine.

[0068] In still yet another embodiment of Aspect E, the FC comprises a hydrogen FC, and the rotating shaft of the electrically-powered turbine assembly is configured to carry liquid hydrogen to cool electric motor windings.

[0069] In yet another embodiment of Aspect E, the system includes one or more inverters having cooling fins configured to extend into the housing and into cooling airflow from the compressor.

[0070] In a particularly preferred embodiment of Aspect E, the vehicle is an aircraft.

[0071] According to Aspect F there is provided an electrically-powered turbine assembly comprising: a fixed housing; an air compressor including one or more compressor rotors, and one or more compressor stators, where one or more of the compressor stators are fixed to the housing; a turbine including one or more turbine rotors, and one or more turbine stators, wherein one or more of the turbine stators are fixed to the housing; a central shaft supported at least in part by one or more compressor stators and the one or more turbine stators; one or more electric motors including an electric motor stators and an electric motor rotors; and one or more FCs arranged on an outside of the housing.

[0072] In one embodiment of Aspect F, the central shaft comprises a rotatable shaft, and the one or more compressor rotors, and the one or more turbine rotors and the one or more electric motor rotors are fixed to rotate with the shaft.

[0073] In another embodiment of Aspect F, the central shaft is fixed in position, the one or more electric motor stators are fixed to, and arranged on a non-rotating shaft, and the air compressor rotor and the turbine rotors are fixed to rotate with the motor rotors around the one or more electric motor stators.

[0074] In another embodiment of Aspect F, the one or more electric motors are also configured to act as electrical generators.

[0075] In a further embodiment of Aspect F, the air compressor and the turbine respectively include one or more counter-rotating rotors. In another embodiment of Aspect F, the non-rotating shaft is configured as a conduit for fluid transfer and / or electrical power. In another embodiment of Aspect F, the one or more compressor stators are configured for carrying an electric current. In such embodiment, the compressor stator may be a passage configured to accommodate an electrical conduit within the one or more stators. Alternatively, the one or more compressor stators are formed of an electrically conductive material configured to carry an electrical current.

[0076] In a further embodiment of Aspect F, the one or more compressor stators have a passage configured to carry a fluid. In such embodiment, the fluid optionally comprises a thermal transfer fluid for cooling the one or more motor stators and / or for cooling air as the air is moved through the air compressor. Optionally, the one or more compressor stators include internal fluidics channels configured to optimize heat exchange and the one or more fuel cells comprise hydrogen fuel cells. Alternatively, the fluid may comprise hydrogen and the hydrogen flowing through the conduit optionally is in liquid form and is configured to receive heat from the assembly to change from the liquid form and is configured to receive heat from the assembly to change from liquid to gas form for use by one or more fuel cells. In yet another embodiment the fluid may comprise a lubricant. In yet another embodiment, the fluid may form a fluid dynamic bearing.

[0077] In a further embodiment of Aspect F, the central shaft segments are mechanically coupled to one another.

[0078] In another embodiment of Aspect F, wherein one or more FCs are arranged around an outside of the housing, and wherein an output from the compressor optionally is coupled to an intake of one or more fuel cell cathodes, wherein an exhaust from the one or more fuel cells optionally is coupled to an anode tail oxidizer, and wherein an inlet manifold for the turbine optionally is configured to contain a catalytic mesh for the anode tail oxidizer. Further, the annular manifold optionally has an outlet configured to deliver air to a cathode side of the one or more FCs, and an anode exhaust from the one or more FCs is passed to the turbine.

[0079] In a further embodiment of Aspect F, the electric motor include fins configured to be cooled by airflow from the compressor.

[0080] In another embodiment of Aspect F, one or more inverters electrically connected to the electric motor, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor.

[0081] In a further Aspect G of the present disclosure, an integrated hydrogen FC electric engine as above described is fitted into an aircraft nacelle.

[0082] In one embodiment of Aspect G, the integrated hydrogen FC electric engine comprises a single, continuous radially-symmetrically shaped FC mounted within a wing nacelle of the aircraft.

[0083] In a further Aspect H of the present disclosure, an electrically-powered turbomachine assembly comprises a housing; a rotating shaft; an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft; an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft; and a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft, and characterized by one or more features, including an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor; and the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft; and the compressor stator is configured for carrying an electric current, and the compressor stator has a passage configured to accommodate an electrical conduit within the stator, and the compressor stator is formed of an electrically conductive material and is configured to carry an electrical current, and the compressor stator has a passage configured to carry a fluid, optionally a thermal transfer fluid, or a lubricant and wherein the lubricant optionally forms a fluid dynamic bearing for supporting the rotating shaft, and the motor stators include cooling fins; and the rotating shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another.

[0084] In another Aspect I, a fuel-cell-powered vehicle having an electrically-powered turbomachine assembly includes one or more FCs arranged around an outside of the electrically-powered turbomachine assembly, and the air compressor optionally is configured to deliver air to a cathode side of the one or more FCs. Anode exhaust from the FC optionally is passed to the turbine, where the electric motor stator includes fins configured to be cooled by airflow from the compressor, and optionally further comprising one or more inverters electrically connected to the electric motors, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor; and the vehicle may be an aircraft.

[0085] According to a first aspect of the present invention there is provided an integrated hydrogen fuel cell (FC) electric engine comprising: a centrifugal compressor and a turbine rotatably mounted, back-to-back on a common shaft; and one or more FCs arranged around an outside of the rotatably mounted centrifugal compressor and the rotatably mounted turbine.

[0086] Preferably the one or more FCs are arranged with their cathode sides closer to the common shaft, wherein airflow from the rotatably mounted centrifugal compressor optionally is directed through the cathode to the turbine and / or wherein an anode tail oxidizer optionally combusts anode exhaust hydrogen with cathode exhaust air and delivers resulting exhaust to the turbine.

[0087] Preferably the hydrogen FC electric engine is characterized by one or more of the following features: (a) wherein the rotatably mounted compressor and the rotatably mounted turbine are housed within an annular duct having an air inlet configured for uninterrupted axial delivery of airflow to the compressor and exhaust of spent air from the turbine via an air exhaust outlet; (b) wherein the one or more FCs comprises a plurality of FCs arranged in a radial array of FCs around the central shaft; (c) wherein the one or more FCs comprises a plurality of FCs in the form of a radial array of substantially rectangularly shaped FC stacks arranged around the central shaft; (d) further comprising one or more fans for moving cooling air through the one or more FCs, optionally (i) wherein one or more fans are configured to be driven by the central shaft; (ii) wherein one or more shafts are configured to be driven by the central through a gearbox driven by the central shaft; (iii) wherein the gearbox comprises planetary gears; (iv) wherein the one or more fans are configured to be driven from their outside rims; and / or (v) wherein one or more fans are configured to be supported on bearings or rollers in contact with the fans’ outer rims; (e) wherein the integrated hydrogen FC electric engine is fitted into an aircraft nacelle; and (f) wherein the one or more FCs comprises a single, continuous radially-symmetrically shaped FC.

[0088] According to a second aspect of the present invention there is provided a hydrogen FC-powered aircraft comprising at least one hydrogen FC electric engine system according to the first aspect of the present invention, and wherein the integrated hydrogen FC electric engine optionally is mounted within the aircraft nacelle of the aircraft.

[0089] According to a third aspect of the present invention there is provided an electrically-powered turbomachine assembly comprising: a fixed housing; an air compressor including one or more compressor rotors, and one or more compressor stators, where one or more of the compressor stators are fixed to the housing; a turbine including one or more turbine rotors, and one or more turbine stators, where one or more of the turbine stators are fixed to the housing; a central shaft supported at least in part by the one or more compressor stators and the one or more turbine stators; one or more electric motors including electric motor stators and electric motor rotors; and one or more FCs arranged on an outside of the housing.

[0090] Preferably the electrically-powered turbomachine assembly is characterized by one or more of the following features: (a) wherein the central shaft comprises a rotatable shaft, and the one or more compressor rotors, the one or more turbine rotors and the one or more electric motor rotors are fixed to rotate with the shaft; (b) wherein the one or more electric motor stators are fixed to , and arranged on a non-rotating shaft, and the air compressor and the turbine rotors are fixed to rotate with the electric motor rotors around the one or more electric motor stators; (c) wherein the one or more electric motors are also configured to act as electrical generators; (d) wherein the air compressor and the turbine respectively include one or more counter-rotating rotors; (e) wherein the non-rotating shaft is configured as a conduit for fluid transfer and / or electrical power; (f) wherein the one or more compressor stators are configured for carrying an electric current and have a passage configured to accommodate an electrical conduit within the one or more stators, or are formed of an electrically conductive material configured to carry an electrical current; (g) wherein one or more compressor stators have a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid for cooling the one or more motor stators and / or for cooling air as the air is moved through the air compressor, and optionally wherein the one or more compressor stators include internal fluidics channels configured to optimize heat exchange, wherein the one or more fuel cells comprise hydrogen fuel cells and the fluid comprises hydrogen and further wherein the hydrogen flowing through the conduit optionally is in liquid form and is configured to receive heat from the assembly to change from liquid form to gas form for use by one or more fuel cells; and wherein the fluid acts as a lubricant, or as a fluid dynamic bearing; (h) wherein the central shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another; (i) wherein one or more fuel cells are arranged radially on an outside of the housing, and wherein an output from the compressor optionally is coupled to an intake of the one or more fuel cells cathodes, wherein an exhaust from the one or more fuel cells optionally is coupled to an anode tail oxidizer, and wherein an inlet manifold for the turbine optionally is configured to contain a catalytic mesh for the anode tail oxidizer; (j) wherein the fixed housing includes an annular manifold having an inlet configured to capture a flow of air from the air compressor; (k) wherein the annular manifold optionally has an outlet configured to deliver air to a cathode side of the one or more FCs; (1) wherein an anode exhaust from the one or more FCs is passed to the turbine; (m) wherein the one or more electric motors include fins configured to be cooled by airflow from the compressor; and (n) further comprising one or more inverters electrically connected to the electric motor, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor.

[0091] According to a fourth aspect of the present invention there is provided a vehicle powered by an electrically powered turbomachine assembly according to the third aspect of the present invention.

[0092] Preferably the electrically powered turbine assembly includes one or more FCs as an electric power source, and / or wherein the vehicle comprises an airplane.

[0093] According to a fifth aspect of the present invention there is provided an electrically-powered turbomachine assembly comprising: a housing; a rotating shaft; an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft; an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft; and a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft.

[0094] Preferably the electrically-powered turbomachine assembly is characterized by one or more of the following features: (a) wherein an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor; (b) wherein the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft; (c) wherein the compressor stator is configured for carrying an electric current; (d) wherein the compressor stator has a passage configured to accommodate an electrical conduit within the stator; (e) wherein the compressor stator is formed of an electrically conductive material and is configured to carry an electrical current; (f) wherein the compressor stator has a passage configured to carry a fluid, optionally a thermal transfer fluid, or a lubricant and wherein the lubricant optionally forms a fluid dynamic bearing for supporting the rotating shaft; (g) wherein the motor stators include cooling fins; and (h) wherein the rotating shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another.

[0095] According to a sixth aspect of the present invention there is provided a fuel-cell-powered vehicle comprising the electrically-powered turbomachine assembly according to the fifth aspect of the present invention, and one or more FCs arranged around an outside of the electrically-powered turbomachine assembly, wherein (a) the air compressor optionally is configured to deliver air to a cathode side of the one or more FCs; wherein (b) anode exhaust from the FC optionally is passed to the turbine; wherein (c) the electric motor stator includes fins configured to be cooled by airflow from the compressor; (d) optionally further comprising one or more inverters electrically connected to the electric motors, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor; and (e) wherein the vehicle is an aircraft.

[0096] According to a seventh aspect of the present invention there is provided a FC-powered vehicle comprising an electrically-powered turbine assembly comprising: a housing; a rotating shaft; an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft; an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft; a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft, and one or more FCs arranged around an outside of the electrically-powered turbine assembly, wherein anode exhaust from the one or more FCs is configured to be passed to the turbine.

[0097] Preferably the FC-powered vehicle is characterized by one or both of the following features: (a) wherein the compressor stator has a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid; and (b) wherein the FC comprises a hydrogen FC, wherein the rotating shaft is configured to carry liquid hydrogen to cool the electric motor windings.

[0098] According to an eighth aspect of the present invention there is provided a FC-powered vehicle comprising an electrically-powered turbine assembly comprising: a housing; a rotating shaft; an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft; an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft; a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft; one or more FCs arranged around an outside of the electrically-powered turbine assembly; and one or more inverters electrically connected to the electric motors, wherein the one or more inverters include cooling fins extending into the housing and into cooling airflow from the air compressor.

[0099] Preferably the FC-powered vehicle is characterized by one or more of the following features: (a) wherein the air compressor is configured to deliver air to a cathode side of the one or more FCs; (b) wherein the electric motor stator includes fins configured to be cooled by airflow from the compressor; (c) wherein the vehicle is an aircraft; (d) wherein an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor; (e) wherein the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft; (f) wherein the compressor stator is configured for carrying an electric current, and wherein the compressor stator optionally has a passage configured to accommodate an electrical conduit within the compressor stator, and / or wherein the compressor stator optionally is formed of an electrically conductive material and is configured to carry an electrical current; (g) wherein the compressor stator has a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid or a lubricant which lubricant optionally forms a fluid dynamic bearing for supporting the rotating shaft; (h) wherein the electric motor stator includes cooling fins; (i) wherein the rotating shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another; and (j) wherein the FC comprises a hydrogen FC, wherein the rotating shaft is configured to carry liquid hydrogen to cool the electric motor windings.

[0100] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0101] Further features and advantages of the disclosure will be seen in the following detailed description, taken in conjunction with the accompanying drawings, wherein like numerals depict line parts. The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure. In the drawings: Fig. 1 is a schematic view of an integrated hydrogen FC electric engine system in accordance with the prior art; Fig. 2 is a schematic view of an integrated hydrogen FC electric engine system in accordance with an embodiment of the present disclosure; Fig. 3 A is a view taken along line 3-3 of Fig. 2; Figs. 3B is a perspective view of an alternative embodiment of the integrated hydrogen FC electric engine systems in accordance with the present disclosure; Fig. 3C is a cross-sectional view of an alternative embodiment of the integrated hydrogen FC electric engine system in accordance with the present disclosure; Fig. 4A is a view, similar to Fig. 2, of yet another alternative embodiment of an integrated hydrogen FC electric engine system in accordance with the present disclosure; Fig. 4B is a cross-sectional view of a FC electric engine system with anode tail oxidizer, in accordance with the present disclosure; Fig 4C is a cross-sectional view of a FC electric engine system with gearboxes to allow various rotational velocities, in accordance with the present disclosure; Fig. 5 is a schematic view of an aircraft including a pair of hydrogen FC electric engine systems in accordance with the present disclosure; Fig. 6 is a schematic view of an integrated hydrogen-electric engine system in accordance with one embodiment of the present disclosure; Fig. 7 is a perspective view, in cross-section of an integrated hydrogen-electric engine system in accordance with a second embodiment of the present disclosure; Fig. 8 is a schematic view of the integrated hydrogen FC electric engine system of Fig. 7; Fig. 9 is a schematic diagram showing the third alternative embodiment of an integrated hydrogen FC electric engine system in accordance with the present disclosure; Fig. 10 is a schematic diagram of the integrated hydrogen FC electric engine system of Fig. 9, and showing airflow, electrical and fluid transfer through the system; and Fig. 11 is a schematic view of an aircraft incorporating a pair of hydrogen FC electric engine systems in accordance with the present disclosure.

[0102] Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0103] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.

[0104] When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0105] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0106] Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below”, or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0107] Referring to Figs. 2 and 3A-3C, an integrated hydrogen FC electric engine 50 in accordance with present disclosure includes a centrifugal compressor 52 and a turbine 54 rotatedly mounted on a common shaft 56. Compressor 52 and turbine 54 are mounted back-to-back on common shaft 56. A plurality of FCs 60A, 60B... are arranged in annular groupings around the outside of the compressor-turbine combination, with the FC cathodes 62A, 62B .. .62N facing toward the inside, i.e., facing shaft 56 and arranged so that air flows from compressor 52 into the cathode inlets 63A, 63B .. .63N on the cathode side of the FCs 60A, 60B.. ..60N, and anodes 64A, 64B.. .64N facing toward the outside. An annular high temperature proton exchange membrane (HT-PEM) 66A, 66B.. .66N is positioned between the anodes 64A, 64B... 64N and the cathodes 62A, 62B ...62N. The air introduced on the cathode side of the FCs 60A, 60B ... 60N reacts with hydrogen (H2) gas introduced on the anode side of the FCs 60A, 60B, .. .60N producing electricity and a cathode reactant gas stream comprising primarily warm air and water. The cathode reactant gaseous stream is then passed via cathode outlets 70A, 70B .. .70N through turbine 54 to extract mechanical work from the stream of warm moist air. The compressor 52 and turbine 54 assembly is housed within an annular duct 76 which includes an air inlet 78 configured for uninterrupted axial delivery of air flow to the compressor 52, and exhaust of spent air via an air exhaust outlet 80 from the turbine 54.

[0108] Referring in particular to Fig. 3B, in an alternative embodiment, the FC is in the form of a single continuous radially-symmetric shaped FC 150 having an annular cathode 162 and annular anode 164 separated by an annular HT-PEM 166, surrounding the centrifugal compressor 52 and turbine 54. Referring to Fig. 3C, in yet another alternative embodiment, the FC is in the form of a radial array of substantially rectangularly shaped FC stacks 260A, 260B ... 260N arranged around the central shaft 56 of turbine 54.

[0109] Referring to Figs. 4A-4C, in still another embodiment the annular duct 76 is surrounded by an outer duct 82, and include inlet fan 83, and outlet fan 85 upstream and downstream of FCs 60A, 60B .. .60N as shown in Fig. 3A, concentrically mounted on shaft 56 for moving cooling air through the FCs. In a preferred embodiment, inlet fan 83 and outlet fan 85 have larger diameters and lower rotational speeds than shaft 56 and may be connected to shaft 56 via gearboxes 86, which typically are planetary gearboxes.

[0110] Alternatively, inlet fan 83 and outlet fan 85 may be driven from their outside rims via electric motors 90. In such case, fans 83 need not be in direct contact with shaft 56 but rather may be supported on bearings or rollers 92 in contact with the fans’ outside rims.

[0111] After the cooling air passes through the FCs and picks up heat, it may be passed through a cooling air turbine 54 (Fig. 3C) to recover some of the heat energy as mechanical work.

[0112] Shaft 56 also may be extended on either end to connect to other mechanical accessories, such as electric motors, generators, gearboxes, hydraulic pumps, etc., shown generally at 94, and / or to propulsion systems such as a propeller 96, usually via a gearbox 57, as shown in FIG. 4C.

[0113] The integrated hydrogen FC electric engine system 50 may be fitted into a conventional aircraft nacelle 98. Typically, the nacelle 98 is mounted on the wing or fuselage of an aircraft. Figure 4B shows an anode tail oxidizer (ATO) 68 which reacts unused hydrogen with cathode exhaust before the exhaust exits through the turbine. The ATO 68 is connected so that it receives the hydrogen that is not consumed at the FC anode 64, and the ATO 68 also receives exhaust containing heated air and water from the cathode 62A, 62B.. .62N. The ATO 68 may comprise a flame combustion reactor or surface catalytic reactor. The resulting gaseous ATO exhaust is expelled to the turbine to recover the heat energy as mechanical energy.

[0114] Fig. 4C shows the use of a gearbox 57 to adapt the rotational velocity of the turbine and compressor section to the rotational velocity of the propeller shaft 58 and propeller 96. Fig 4C also shows that a gearbox 86 can adapt the rotational velocity of the turbine and compressor section to the coolant inlet fan 83. Additionally, Fig 4C shows that coolant inlet fan 83 and coolant outlet fan 84 may be powered by electric motors 90 and supported by bearings 92.

[0115] Fig. 5 illustrates an aircraft 95 including a pair of integrated hydrogen FC electric engine systems 50 in the nacelles 98 of the aircraft in accordance with the present disclosure.

[0116] Fig 6 illustrates an integrated hydrogen-electric engine system 100 that can be utilized, for example, in a turboprop or turbofan system in accordance with the present disclosure. Integrated hydrogen-electric engine system 100 includes an elongated shaft 102 that defines a longitudinal axis “L” and extends through the entire powertrain of integrated hydrogen-electric engine system 100 to function as a common shaft for the various components of the powertrain. Elongated shaft 102 supports a propulsor 104 (e.g.. a fan or propeller) and a multi-stage air compressor section 106 comprising a plurality of compressor rotors 108A, 108B, 108C and a turbine section 110 comprising a turbine rotor 112. Compressor rotors 108A, 108B, 108C and turbine rotor 112 are fixed to rotating shaft 102. A plurality of electric motor cores 124A, 124B, 124C are also rotatably fixed to rotating shaft 102 within the multi-stage air compressor section 106, and an electric motor core 124D is fixed to rotating shaft 102 in turbine section 110. The air compressor motor housings 128A, 128B, 128C are supportably fixed to housing 125 on air compressor stators 126A, 126B, 126C. The turbine motor housing 128D is supportably fixed to housing 125 on turbine stator 126D. Electric motor housings 128A, 128B, 128C are affixed to air compressor stators 126A, 126B, 126C, and electric motor housing 128D is affixed to turbine stator 126D which in turn is fixed to housing 125. Electric motor housings 128A, 128B, 128C and 128D also form the stators for the electric motors. Shaft 102 is rotatably supported within compressor stators 126A, 126B, 126C and turbine stator 126D on bearing pairs 130A, 130B, 130C, 130D, respectively.

[0117] Compressor motor stators 126A, 126B, 126C, and turbine motor stator 126D include internal passages 160A, 160B, 160C, 160D for carrying coolant air to and from the electric motor cores 124A, 124B, 124C, 124D. Internal passages 160A, 160B, 160C, 160D also may be configured to deliver lubricant to bearings 130A, 130B, 130C, 130D. Compressor motor stators 126A, 126B, 126C and turbine motor stator 126D also may be configured for accommodating electrical wiring for carrying electricity generated by the FCs 138 (only one of which is shown, and not to scale) to power the electric motors. Alternatively, compressor or turbine motor stators 126A, 126B, 126C, 126D may be formed of electrically conductive materials for carrying electric current to the electric motors.

[0118] The integrated hydrogen-electric engine system 100 also includes inverter(s) 140 located immediately to the outside of housing 125 with the shortest path to each motor. Inverter(s) 140 may include cooling fin(s) 142 extending into housing 125 in contact with the compressor airflow 144. In similar manner, the electric compressor motor stators 128A, 128B, 128C may include cooling fin(s) 129, and the compressor airflow also may be used to cool the electric motors. Inverter(s) 140 are configured to convert direct current from the FCs 138 to alternating current for actuating the one or more electric motor(s) in electrical communication with inverter(s) 140. The one or more electric motor(s) drives elongated shaft 102 which carries the compressor rotors 108A, 108B, 108C and propulsor 104.

[0119] In operation, compressor airflow 144 is introduced into air inlet 180 and compressed by the air compressor section 106 and passed via high pressure air outlet 182 to the cathode side 184 of FC 138 where the oxygen in the air is reacted with hydrogen to produce electricity and reaction exhaust comprising primarily hot air and hot water. The water is separated, and the hot air exhaust from the FC 138 is passed via turbine inlet 185 to the turbine section 110 where it is used for driving the one or more turbine rotors 112. Optionally, the hydrogen exhaust from the FC anode 186 can be combined with the exhaust from the FC cathode 184 and combusted in an anode tail oxidizer (ATO) 188 before returning to the turbine inlet 185.

[0120] Integrated hydrogen-electric engine system 100 further includes a controller 300 for controlling the various aspects of the integrated hydrogen-electric engine system 100 and / or other components of the aircraft system. For example, controller 300 can be configured to manage a flow of liquid hydrogen, manage coolant liquids and rates of hydrogen and air going into the system and / or flows of hydrogen fuel and air to the FCs.

[0121] Alternatively, fluids for cooling the electric motors and fluids for lubricating the shaft bearings may be piped in the passages 160A, 160B, 160C, 160D within the compressor motor stators 126A, 126B, 126C and the turbine motor stator 126D. The passages may enclose fluid flow tubes, or the passages may be hollow passages connecting the inner and outer ends of the stators. We also can include sensors and phase encoders (not shown) within the motor stators. Also, different stators may be connected to different phase leads of the electric motors.

[0122] The rotating shaft 102 may comprise a unitary shaft or segmented shaft in which the segments are mechanically connected together by splines, couplings, gears and / or clutches. Shaft(s) 102 also may be provided with passage(s) 190 for conveying fluids from one location along shaft to another. Seals and rotating couplings (not shown) can enable multiple fluids to be conveyed to and from multiple locations within the integrated hydrogen-electric engine system.

[0123] In one embodiment, the shaft 102 may be configured to carry cryogenic fluids, including, for example, LH2 from the fuel store, to the electric motors. This would enable us to employ superconducting motor windings.

[0124] In other embodiments, FCs are positioned at radial locations on the outside of a central duct of the integrated hydrogen-electric engine system where a compressor (axial or centrifugal) is driven by motors and a turbine is fixed along a central shaft. Two such other embodiments are envisioned, in which the arrangement of rotor components of the compressor and the electric motors are nested within each other. A first embodiment comprising an inrunner motor configuration where the motor rotor is on the inside of its stator (Figs. 7 and 8), as will be described below in detail, and an outrunner configuration where the motor rotor is on the outside of its stator (Figs. 9-11) as will be described below in detail.

[0125] Figs. 7 and 8 illustrate a second embodiment of an integrated hydrogen-electric engine system 500 that can be utilized, for example, in a turboprop or turbofan system in accordance with the present disclosure. For the sake of illustration, non-electrical common elements such as the propulsor have been omitted. Integrated hydrogen-electric engine system 500 includes an elongated shaft 502 that defines a longitudinal axis “L” and extends through the entire powertrain of integrated hydrogen-electric engine system 500 to function as a common shaft for the various components of the powertrain. Elongated shaft 502 supports a propulsor (e.g., a fan or propellor) (not shown), a plurality of electric motors 505A, 505B, 505C, 505D within a multistage air compressor section 506 which includes a plurality of compressor rotors 508A, 508B, 508C, and a turbine rotor 509 within a turbine section 510. Shaft 502 is rotatably supported on compressor stators 526A, 526B, 526C and turbine stator 526D. Each electric motor 505A, 505B, 505C, 505D includes a motor core 524A, 524B, 524C, 524D, and a motor housing including a stator 526A, 5262B, 526C, 526D. Compressor rotors 508A, 508B, 508C and turbine rotor 512 are fixed to shaft 502.

[0126] Shaft 502 is rotatably supported within compressor stators 526A, 526B, 526C and turbine stator 526D on bearing pairs 530A, 530B, 530C, 530D.

[0127] As in the case of the Fig. 6 embodiment, compressor stators 526A, 526B, 526C, and turbine stator 526D include internal passages 560A, 560B, 560C, 560D for carrying coolant air to and from the electric motors 505A, 505B, 505C, 505D. The internal passages also may be configured to deliver lubricant to bearings (not shown). Compressor stators 526A, 526B, 526C and turbine stator 526D also may be configured for accommodating electrical wiring for carrying electricity generated by FC stacks 538 which are radially mounted on the exterior of housing 525 which acts both as a mechanical support and an aerodynamic duct. Alternatively, compressor or turbine stators 526A, 526B, 526C, 526D may be formed of electrically conductive materials for carrying electric current to the electric motors.

[0128] FC stacks 538 include heat exchanger inlet faces 527 and heat exchanger outlet faces 529. An annular cathode manifold plenum 531 is provided and is configured to deliver compressed air from the air compressor section 506 to the inlet faces of the FC stacks 538.

[0129] Also, as in the case of the Fig. 6 embodiment, the integrated hydrogen-electric engine system 500 also includes inverter 580 located immediately to the outside of housing 525 with the shortest path to each motor. The inverter(s) may include cooling fins 582 extending into housing 525 in contact with the compressor airflow 544. In similar manner as the Fig. 6 embodiment, the electric motor stators 528A, 528B, 528C and 528D may include cooling fins 531, and the compressor airflow also may be used to cool the electric motors. The inverter(s) are configured to convert direct current from the FC stacks 538 to alternating current for actuating the one or more electric motor(s) in electrical communication with inverter(s). The one or more electric motor(s) 505A, 505B, 505C, 505D drives elongated shaft 502 which carries the compressor rotors 508A, 508B, 508C and propulsor.

[0130] In operation, airflow 544 is introduced into air inlet 581 and compressed by the air compressor section 506 and passed via annular cathode manifold plenum 531 to the cathode side 584 of FC stack 538 where the oxygen in the air is reacted with hydrogen to produce electricity and reaction exhaust comprising primarily hot air and hot water. The water is separated, and the hot air exhaust from the FC stack 538 is passed via turbine inlet 585 to the turbine section 510 where it is used for driving the one or more turbine rotors 512. Optionally, the hydrogen exhaust from the FC anode 586 can be combined with the exhaust from the FC cathode 584 and combusted in an anode tail oxidizer 590, to harvest additional enthalpy to drive the turbine. Excess enthalpy in the flow after the turbine can be used to generate thrust direct through a nozzle 587.

[0131] Integrated hydrogen-electric engine system 500 further includes a controller 600 for controlling the various aspects of the integrated hydrogen-electric engine system 500 and / or other components of the aircraft system. For example, controller 600 can be configured to manage a flow of liquid hydrogen, coolant liquids and rates of hydrogen and air going into the system and / or flows of hydrogen fuel and air to the FCs.

[0132] Referring to Figs. 9 and 10, there is illustrated a further embodiment of our disclosure. As in the case of the Figs. 7 and 8 embodiment, non-electrical common elements such as the propulsor have been omitted.

[0133] The embodiment shown in Figs. 9 and 10 is similar to the embodiment shown in Figs. 7 and 8 in many respects. However, in the embodiment shown in Figs. 9 and 10, the central shaft is fixed, the electric motor stators are fixed to the shaft, the electric motor rotors and electric motor housings are configured to rotate around the electric motor stators, and the compressor rotors and the turbine rotors are configured to rotate with the electric motor rotors and housings.

[0134] Referring to Figs. 9 and 10, there is shown an integrated hydrogen-electric engine system 1500 that includes an elongated shaft 1502 that defines a longitudinal axis “L” and extends through the entire powertrain of integrated hydrogen-electric engine system 1500 to function as a common shaft for the various components of the powertrain. Elongated shaft 1502 is fixed in place, and supports a plurality of electric motors 1505A, 1505B ... within a multi-stage air compressor section 1506 which includes a plurality of compressor rotors 1508A, 1508B ... and an electric motor 1505D within a turbine section 1510 comprising a turbine rotor 1512. Shaft 1502 is supported on compressor stators 1526A, 1526B, 1526C... and turbine stator 1526D. Each electric motor 1505A, 1505B ... 1505D includes a motor stator 1528A, 1528B ... 1528D, which is fixed to shaft 1502, rotating motor rotors 1524A, 1524B ... and 1524D, or rotating motor housing which act as the motor rotors. Compressor rotors 1508A, 1508B ... and turbine rotor 1512 are supportedly fixed to rotating motor rotor 1524A, 1524B ... 1524D, respectively. Electric motor stators 1528A, 1528B ... are fixed to shaft 1502 within the multi-stage air compressor section 1506, and an electric motor stator 1528D is fixed to shaft 1502 in turbine section 1510.

[0135] As in the case of the Figs. 7-8 embodiment, compressor stators 1526A, 1526B, 1526C ... and turbine stator 1526D include internal passages (not shown) for carrying coolant air to and from the electric motors 1505A, 1505B ... 1505D. The internal passages also may be configured to deliver lubricant to bearings (not shown). Also, as in the case of the Figs. 7-8 embodiment compressor stators 1526A, 1526B, 1526C ... and turbine stator 1526D may be configured for accommodating electrical wiring for carrying electricity generated by FC stacks 1538 on the exterior of housing 1525. Alternatively, compressor or turbine stators 1526A, 1526B, 1526C ... 1526D may be formed of electrically conductive materials for carrying electric current to the electric motors.

[0136] Also, as in the case of the earlier described embodiments FC stacks 1538 may include heat exchanger inlet faces (not shown) and heat exchanger outlet faces (not shown), and are radially mounted to the exterior of housing 1525. Also as in the case of the Figs. 7-8 embodiment, an annular cathode manifold plenum (not shown) may be provided and configured to deliver compressed air from the air compressor section 1506 to the inlet faces of the FC stacks 1538.

[0137] Also, as in the case of the earlier described embodiments, the integrated hydrogenelectric engine system 1500 includes inverters (not shown) located immediately to the outside of housing 1525 with the shortest path to each motor. The inverter(s) may include cooling fins (not shown) extending into housing 1525 in contact with the compressor airflow 1544. In similar manner as the earlier described embodiments, the electric motor stators 1528A, 1528B, 1528D may include cooling fin(s) (not shown), and the compressor airflow also may be used to cool the electric motors. The inverter(s) are configured to convert direct current from the FC stacks 1538 to alternating current.

[0138] Referring in particular to Fig. 10, shaft 1502 may include passages 1610 within the shaft configured to convey fluids from one location along the shaft to another. Seals and rotating couplings (not shown) may be provided to enable multiple fluids to be conveyed to and from multiple locations. In particular, rotating seals may enable a coolant or lubricant to pass from the stationary shaft 1502 to the rotating motor rotors 1508A, 1508B ... 1512. In some cases, the fluids may be cryogenic coolants, including LH2. This could enable superconducting motor windings. The turbine generator and compressor motors are electrically coupled, so that energy recovered from the turbine can be used to power the compressor. In one embodiment, electrical connections may be routed through the shaft 1502.

[0139] In operation, air is introduced into air inlet 1580 and compressed by the air compressor section 1506 and passed to the cathode side 1584 of FC stack 1538 where the oxygen in the air is reacted with hydrogen to produce electricity and reaction exhaust comprising primarily hot air and hot water. The water is separated, and the hot air exhaust from the FC stack 1538 is passed to the turbine section 1510 where it is used for driving the one or more turbine rotors 1512. Optionally, the hydrogen exhaust from the FC anode 1586 can be combined with the exhaust from the FC cathode 1584 and combusted in an anode tail oxidizer 1588, to harvest additional enthalpy to drive the turbine. Excess enthalpy in the flow after the turbine can be recycled via conduit 1596 to the FC stack 1538 where it is mixed with fresh cold air at 1598 to condition the ram air stream, or the warm air from the turbine may be employed to gasify LH2 feed for the FCs.

[0140] Integrated hydrogen-electric engine system 1500 further includes a controller 1600 for controlling the various aspects of the integrated hydrogen-electric engine system 1500 and / or other components of the aircraft system. For example, controller 1600 can be configured to manage a flow of liquid hydrogen, manage coolant liquids and rates of hydrogen and air to the FCs.

[0141] Fig. 11 illustrates an aircraft 1000 including a pair of hydrogen FC electric engine systems 500 as above described in the wing nacelles 1002 of the aircraft.

[0142] A feature and advantage of the instant disclosure is that the housing, compressor stators, electric motor stator and turbine stators each serve multiple functions. This results in fewer components being needed, and a corresponding weight reduction. Also packaging the electric motor cores within the compressor section and turbine section permits us to provide an extremely compact hydrogen FC-powered electric engine system providing high power density, which may be sized and shaped to fit within the existing conventional aircraft wing nacelle.

[0143] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. Various changes and advantages may be made in the above disclosure without departing from the spirit and scope thereof. 66A, 66B...66N HT-PEM List of References: 68 ATO 1 hydrogen-electric engine system 70A, 70B.. .70N cathode outlets 10 elongated shaft 76 annular duct 12 air compressor system 78 air inlet 12a inlet portion 80 air exhaust outlet 12b compressor portion 82 outer duct 14 propulsor 83 inlet fan 16 wheels 84 outlet fan 17 wastegates 86 gearboxes 18 gearbox 88 air turbine 19 external radiators 90 electric motors 20 fuel source 92 bearings or roller 22 fuel pump 94 electric motors, generators, 24 heat exchanger gearboxes, hydraulic pumps 26 FC stack 95 aircraft 29 inverters 96 propeller 30 motor assembly 98 nacelle 39 heater 100 hydrogen-electric engine system 50 hydrogen FC electric engine system 102 elongate shaft 52 centrifugal compressor 104 propulsor 54 turbine 106 compressor section 56 common shaft 108A, 108B, 108C compressor rotors 57 gearbox 110 turbine section 58 propeller shaft 112 turbine rotor 60A, 60B...60N FC 124A, 124B, 124C, 124D electric motor 62 cathode cores 62A, 62B... 62N FC cathodes 125 housing 63A, 63B... 63N cathode inlets 126A, 126B, 126C compressor motor 64 FC anodes stator 64A, 64B...64N anodes 126D turbine motor stator 128A, 128B, 128C compressor motor 510 turbine section housings 512 turbine rotors 128D turbine motor housing 524A, 524B, 524C, 524D motor core 129 cooling fin 525 housing 130A, 130B, 130C, 130D bearing pairs 526A, 526B, 526C compressor stators 138 FCs 526D turbine stator 140 inverter 527 inlet faces 142 cooling fin 528A, 528B, 528C, 528D electric motor 144 compressor airflow stators 150 FC 529 outlet faces 160A, 160B, 160C, 160D internal 531 cooling fins passages 530A, 530B, 530C, 530D bearing pairs 162 annular cathode 531 annular cathode manifold plenum 164 annular anode 538 FC stacks 166 annular HT-PEM 544 airflow 180 air inlet 560A, 560B, 560C, 560D internal 182 air outlet passages 184 cathode side 580 inverter 185 turbine inlet 581 air inlet 186 FC anode 582 cooling fins 188 ATO 584 FC cathode side 190 passages 585 turbine inlet 200 controller 586 FC anode 260A, 260B.. .260N FC stacks 590 ATO 300 controller 587 nozzle 500 integrated hydrogen-electric engine 600 controller system 1000 aircraft 502 elongated shaft 1002 nacelles 505A, 505B, 505C, 505D electric motors 1500 integrated hydrogen-electric engine 506 air compressor section system 508A, 508B, 508C compressor rotors 1502 elongated shaft 1505A, 1505B... electric motors 1505D electric rotor 1506 air compressor system 1508A, 1508B ...compressorrotors 1510 turbine section 1512 turbine rotors 1524A, 1524B...1524D motor rotors 1525 housing 1526A, 1526B ... compressor stators 1526D turbine stator 1528A, 1528B... 1528D motor stator 1538 FC stack 1544 airflow 1580 air inlet 1584 cathode side 1586 FC anode 1588 ATO 1596 conduit 1598 fresh cold air mixed 1600 controller 1610 passages

Claims

1. An integrated hydrogen fuel cell (FC) electric engine comprising:a centrifugal compressor and a turbine rotatably mounted, back-to-back on a common shaft; andone or more FCs arranged around an outside of the rotatably mounted centrifugal compressor and the rotatably mounted turbine.

2. The integrated hydrogen FC electric engine of claim 1, wherein the one or more FCs are arranged with their cathode sides closer to the common shaft, wherein airflow from the rotatably mounted centrifugal compressor optionally is directed through the cathode to the turbine and / or wherein an anode tail oxidizer optionally combusts anode exhaust hydrogen with cathode exhaust air and delivers resulting exhaust to the turbine.

3. The integrated hydrogen FC electric engine of claim 1 or claim 2, characterized by one or more of the following features:(a) wherein the rotatably mounted compressor and the rotatably mounted turbine are housed within an annular duct having an air inlet configured for uninterrupted axial delivery of airflow to the compressor and exhaust of spent air from the turbine via an air exhaust outlet;(b) wherein the one or more FCs comprises a plurality of FCs arranged in a radial array of FCs around the central shaft;(c) wherein the one or more FCs comprises a plurality of FCs in the form of a radial array of substantially rectangularly shaped FC stacks arranged around the central shaft;(d) further comprising one or more fans for moving cooling air through the one or more FCs, optionally (i) wherein one or more fans are configured to be driven by the central shaft; (ii) wherein one or more shafts are configured to be driven by the central through a gearbox driven by the central shaft; (iii) wherein the gearbox comprises planetary gears; (iv) wherein the one or more fans are configured to be driven from their outside rims; and / or (v) wherein one or more fans are configured to be supported on bearings or rollers in contact with the fans’ outer rims;(e) wherein the integrated hydrogen FC electric engine is fitted into an aircraft nacelle; and(f) wherein the one or more FCs comprises a single, continuous radially-symmetrically shaped FC.

4. A hydrogen FC-powered aircraft comprising at least one hydrogen FC electric engine system as claimed in any of claims 1 -2, and wherein the integrated hydrogen FC electric engine optionally is mounted within the aircraft nacelle of the aircraft.

5. An electrically-powered turbomachine assembly comprising:a fixed housing;an air compressor including one or more compressor rotors, and one or more compressor stators, where one or more of the compressor stators are fixed to the housing;a turbine including one or more turbine rotors, and one or more turbine stators, where one or more of the turbine stators are fixed to the housing;a central shaft supported at least in part by the one or more compressor stators and the one or more turbine stators;one or more electric motors including electric motor stators and electric motor rotors; and one or more FCs arranged on an outside of the housing.

6. The electrically-powered turbomachine assembly of claim 5, characterized by one or more of the following features:(a) wherein the central shaft comprises a rotatable shaft, and the one or more compressor rotors, the one or more turbine rotors and the one or more electric motor rotors are fixed to rotate with the shaft;(b) wherein the one or more electric motor stators are fixed to , and arranged on a non-rotating shaft, and the air compressor and the turbine rotors are fixed to rotate with the electric motor rotors around the one or more electric motor stators;(c) wherein the one or more electric motors are also configured to act as electrical generators;(d) wherein the air compressor and the turbine respectively include one or more counter-rotating rotors;(e) wherein the non-rotating shaft is configured as a conduit for fluid transfer and / or electrical power;(f) wherein the one or more compressor stators are configured for carrying an electric current and have a passage configured to accommodate an electrical conduit within the one or more stators, or are formed of an electrically conductive material configured to carry an electrical current;(g) wherein one or more compressor stators have a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid for cooling the one or more motor stators and / or for cooling air as the air is moved through the air compressor, and optionally wherein the one or more compressor stators include internal fluidics channels configured to optimize heat exchange, wherein the one or more fuel cells comprise hydrogen fuel cells and the fluid comprises hydrogen and further wherein the hydrogen flowing through the conduit optionally is in liquid form and is configured to receive heat from the assembly to change from liquid form to gas form for use by one or more fuel cells; and wherein the fluid acts as a lubricant, or as a fluid dynamic bearing;(h) wherein the central shaft comprises a segmented shaft, wherein the shaft segments are mechanically coupled to one another;(i) wherein one or more fuel cells are arranged radially on an outside of the housing, and wherein an output from the compressor optionally is coupled to an intake of the one or more fuel cells cathodes, wherein an exhaust from the one or more fuel cells optionally is coupled to an anode tail oxidizer, and wherein an inlet manifold for the turbine optionally is configured to contain a catalytic mesh for the anode tail oxidizer;(j) wherein the fixed housing includes an annular manifold having an inlet configured to capture a flow of air from the air compressor;(k) wherein the annular manifold optionally has an outlet configured to deliver air to a cathode side of the one or more FCs;(1) wherein an anode exhaust from the one or more FCs is passed to the turbine;(m) wherein the one or more electric motors include fins configured to be cooled byairflow from the compressor; and(n) further comprising one or more inverters electrically connected to the electric motor, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor.

7. A vehicle powered by an electrically powered turbomachine assembly as claimed in claim 5 or claim 6.

8. The vehicle of claim 7, wherein the electrically powered turbine assembly includes one ormore FCs as an electric power source, and / or wherein the vehicle comprises an airplane.

9. An electrically-powered turbomachine assembly comprising:a housing;a rotating shaft;an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft;an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft; anda turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft.

10. The electrically-powered turbomachine assembly of claim 9, characterized by one or more of the following features:(a) wherein an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor;(b) wherein the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft;(c) wherein the compressor stator is configured for carrying an electric current;(d) wherein the compressor stator has a passage configured to accommodate anelectrical conduit within the stator;(e) wherein the compressor stator is formed of an electrically conductive material and is configured to carry an electrical current;(f) wherein the compressor stator has a passage configured to carry a fluid, optionallya thermal transfer fluid, or a lubricant and wherein the lubricant optionally forms a fluid dynamic bearing for supporting the rotating shaft;(g) wherein the motor stators include cooling fins; and(h) wherein the rotating shaft comprises a segmented shaft, wherein the shaftsegments are mechanically coupled to one another.

11. A fuel-cell-powered vehicle comprising the electrically-powered turbomachine assemblyas claimed in claim 9 or claim 10, and one or more FCs arranged around an outside of the electrically-powered turbomachine assembly, wherein(a) the air compressor optionally is configured to deliver air to a cathode side of the one or more FCs; wherein(b) anode exhaust from the FC optionally is passed to the turbine; wherein(c) the electric motor stator includes fins configured to be cooled by airflow from the compressor;(d) optionally further comprising one or more inverters electrically connected to the electric motors, wherein the one or more inverters include cooling fins extending into the housing and into the cooling airflow from the compressor; and(e) wherein the vehicle is an aircraft.

12. A FC-powered vehicle comprising an electrically-powered turbine assembly comprising: a housing;a rotating shaft;an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft;an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft;a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft, andone or more FCs arranged around an outside of the electrically-powered turbine assembly, wherein anode exhaust from the one or more FCs is configured to be passed to the turbine.

13. The FC-powered vehicle of claim 12, characterized by one or both of the following features:(a) wherein the compressor stator has a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid; and(b) wherein the FC comprises a hydrogen FC, wherein the rotating shaft is configured to carry liquid hydrogen to cool the electric motor windings.

14. A FC-powered vehicle comprising an electrically-powered turbine assembly comprising:a housing;a rotating shaft;an air compressor comprising a compressor stator fixed to the housing and a compressor rotor fixed to the rotating shaft;an electric motor including an electric motor stator fixed to the compressor stator, and an electric motor rotor fixed to the rotating shaft;a turbine including a turbine stator fixed to the housing, and a turbine rotor fixed to the rotating shaft;one or more FCs arranged around an outside of the electrically-powered turbine assembly; andone or more inverters electrically connected to the electric motors, wherein the one or more inverters include cooling fins extending into the housing and into cooling airflow from the air compressor.

15. The FC-powered vehicle of claim 14, characterized by one or more of the following features:(a) wherein the air compressor is configured to deliver air to a cathode side of the one or more FCs;(b) wherein the electric motor stator includes fins configured to be cooled by airflow from the compressor;(c) wherein the vehicle is an aircraft;(d) wherein an electric motor or generator is affixed to the turbine stator, and a turbine rotor is fixed to the motor or generator rotor;(e) wherein the electric motor rotor, the compressor rotor, and the turbine rotor are mechanically linked together via the rotating shaft;(f) wherein the compressor stator is configured for carrying an electric current, and wherein the compressor stator optionally has a passage configured to accommodate an electrical conduit within the compressor stator, and / or wherein the compressor stator optionally is formed of an electrically conductive material and is configured to carry an electrical current;(g) wherein the compressor stator has a passage configured to carry a fluid, wherein the fluid optionally comprises a thermal transfer fluid or a lubricant which lubricant optionally forms a fluid dynamic bearing for supporting the rotating shaft;(h) wherein the electric motor stator includes cooling fins;(i) wherein the rotating shaft comprises a segmented shaft, wherein the shaftsegments are mechanically coupled to one another; and(j) wherein the FC comprises a hydrogen FC, wherein the rotating shaft is configured to carry liquid hydrogen to cool the electric motor windings.

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