Embedded Motor

Abstract

A gas turbine engine defines a working air flow path and includes an electrical system having an electric machine coupled to a rotating component at least partially inboard of the working air flow path in a radial direction and an electrical bus electrically coupled to the electric machine. The electrical bus includes electrical wires extending through the working air flow path within or downstream of the turbine section. The engine further includes a cooling system including a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wires extending through the working air flow path are substantially embedded within the cooling fluid supply line, and wherein a portion of the cooling fluid supply line extending through the working air flow path is substantially embedded within the cooling fluid return line.

Description

Technical Field

[0001] The present subject matter generally relates to a gas turbine engine having an embedded electric machine. Background Art

[0002] A typical aircraft propulsion system includes one or more gas turbine engines. For some propulsion systems, the gas turbine engine generally includes a fan and a core arranged to be fluidly connected to each other. In addition, the core of the gas turbine engine generally includes a compressor section, a combustion section, a turbine section, and an exhaust section in a series flow sequence. In operation, air is provided from the fan to the inlet of the compressor section, wherein one or more axial flow compressors gradually compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned in the combustion section to provide combustion gases. The combustion gases are directed from the combustion section to the turbine section. The combustion gas flow through the turbine section drives the turbine section and is then directed to, for example, the atmosphere through the exhaust section.

[0003] For some aircraft, it may be beneficial for the propulsion system to include electric fans to supplement the propulsion power provided by one or more gas turbine engines (included in the propulsion system). However, there may be space and weight limitations in providing an aircraft with a sufficient number of energy storage devices to power the electric fans. It is worth noting that some gas turbine engines may include auxiliary generators positioned, for example, within the cowling of the gas turbine engine. However, these auxiliary generators may not be configured to provide a sufficient amount of electricity to adequately drive the electric fans.

[0004] It would therefore be useful to have a propulsion system for an aircraft having one or more gas turbine engines and an electrical generator capable of providing the required amount of electrical power to the electrical propulsion. Summary of the invention

[0005] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0006] In an exemplary embodiment of the present disclosure, a gas turbine engine defining a radial direction and an axial direction is provided. The gas turbine engine includes: a compressor section and a turbine section, the compressor section and the turbine section are arranged in a series flow sequence, the compressor section and the turbine section jointly define a working air flow path; a rotating component capable of rotating together with at least a portion of the compressor section and at least a portion of the turbine section; an electrical system, the electrical system including an electric motor and an electrical bus, the electric motor is coupled to the rotating component at least partially inside the working air flow path in a radial direction, the electrical bus is electrically coupled to the electric motor, the electrical bus includes an electrical wire extending through the working air flow path within the turbine section or downstream of the turbine section; and a cooling system, the cooling system including a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wire extending through the working air flow path is substantially embedded in the cooling fluid supply line, and wherein a portion of the cooling fluid supply line extending through the working air flow path is substantially embedded in the cooling fluid return line.

[0007] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various aspects of the present invention and together with the description serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification, which refers to the accompanying drawings, in which:

[0009] Figure 1 is a top view of an aircraft according to various exemplary embodiments of the present disclosure.

[0010] Figure 2 yes Figure 1 A port side view of an exemplary aircraft.

[0011] Figure 3 is a schematic cross-sectional view of a gas turbine engine according to an exemplary aspect of the present disclosure.

[0012] Figure 4 is a schematic cross-sectional view of an electric machine embedded in a gas turbine engine according to an exemplary embodiment of the present disclosure.

[0013] Figure 5 is a close-up schematic cross-sectional view of electrical wires embedded in cooling fluid supply lines and cooling fluid return lines according to various exemplary embodiments of the present disclosure.

[0014] Figure 6 is along Figure 5 Line 6-6 Figure 5Schematic cross-sectional view of electrical wires embedded in cooling fluid supply and return lines.

[0015] Figure 7 is a close-up schematic cross-sectional view of an electric machine according to an exemplary embodiment of the present disclosure.

[0016] Figure 8 is a schematic cross-sectional view of an electric machine embedded in a gas turbine engine according to another exemplary embodiment of the present disclosure.

[0017] Fig. 9 is a schematic cross-sectional view of an electric machine embedded in a gas turbine engine according to yet another exemplary embodiment of the present disclosure.

[0018] Fig.10 is a schematic illustration of a plurality of wires embedded in a cooling fluid supply line and a cooling fluid return line according to various exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the present embodiments of the present invention, one or more examples of which are shown in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar reference numerals in the drawings and the specification are used to refer to like or similar parts of the present invention.

[0020] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless otherwise specifically stated, all embodiments described herein should be considered exemplary.

[0021] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of a single component.

[0022] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, with respect to a gas turbine engine, front refers to a position closer to the engine inlet and rear refers to a position closer to the engine nozzle or exhaust.

[0023] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction to which the fluid is flowing.

[0024] Unless stated otherwise, the terms "coupled," "fixed," "attached," and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment through one or more intermediate components or features.

[0025] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0026] Approximate language used throughout the specification and claims herein is used to modify any quantitative representation that can be allowed to vary without causing a change in the basic function associated therewith. Therefore, values ​​modified by one or more terms, such as "approximately", "approximately" and "substantially", are not limited to the precise values ​​specified. In at least some instances, approximate language may correspond to the accuracy of an instrument used to measure the value, or the accuracy of a method or machine used to build or manufacture a component and / or system. For example, approximate language may refer to a margin of 1, 2, 4, 10, 15 or 20%. These approximate margins may be applied to a single value defining one or both endpoints of a numerical range and / or the margin of a range between the endpoints.

[0027] Here and throughout the specification and claims, range limitations are combined and interchanged, and unless context or language indicates otherwise, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0028] The present disclosure generally relates to a gas turbine engine for a propulsion system of an aircraft having an electric machine embedded therein. In at least some embodiments, the gas turbine engine includes a compressor section and a turbine section arranged in a series flow sequence, and the compressor section and the turbine section together define a working air flow path. A rotating component, such as a shaft or spool, can rotate with at least a portion of the compressor section and the turbine section.

[0029] The propulsion system and / or the gas turbine engine additionally include an electrical system and a cooling system. The electrical system includes an electric motor and an electrical bus embedded in the gas turbine engine. For example, the electric motor can rotate with the rotating component and be positioned at least partially coaxially with the rotating component in the radial direction of the gas turbine engine inside the working air flow path. For example, in at least some embodiments, the electric motor can be a generator driven by the rotating component. The electrical bus includes wires extending through the working air flow path in the turbine section or downstream of the turbine section.

[0030] The cooling system is configured to maintain the temperature of the electric machine and the electrical bus within a desired operating temperature range regardless of their respective locations within the hot section of the engine. In particular, the cooling system includes a cooling fluid supply line and a cooling fluid return line. A portion of the electrical wires extending through the working air flow path are substantially embedded within the cooling fluid supply line, and a portion of the cooling fluid supply line extending through the working air flow path are substantially embedded within the cooling fluid return line. In this way, the electrical wires extending through the working air flow path are well clear of the hot gases flowing through the turbine section of the engine, and further, the relatively cool cooling fluid flow through the cooling fluid supply line also avoids the hot gases flowing through the turbine section of the engine.

[0031] The relatively cool cooling fluid passing through the cooling fluid supply line may be used to cool the embedded electric machine and optionally other components located within the hot section of the engine (eg, sump, bearings, etc.).

[0032] A gas turbine engine according to this configuration may allow for the inclusion of an embedded electric machine capable of generating large amounts of electrical power and transmitting such power at high voltage through the working air flow path, thereby reducing the risk of significant losses, such as corona discharge losses.

[0033] Referring now to the drawings, wherein like numerals refer to like elements throughout, Figure 1 A top view of an exemplary aircraft 10 is provided that may incorporate various embodiments of the present invention. Figure 2 Provided as in Figure 1 The aircraft 10 is shown in a port side view. Figure 1 and 2 The aircraft 10 defines a longitudinal centerline 14 extending therethrough, a vertical direction V, a lateral direction L, a forward end 16, and a rearward end 18.

[0034] In addition, the aircraft 10 includes a fuselage 12 and a pair of wings 20 extending longitudinally from a front end 16 of the aircraft 10 toward a rear end 18 of the aircraft 10. As used herein, the term "fuselage" generally includes the entire body of the aircraft 10, such as the tail of the aircraft 10. A first of such wings 20 extends laterally outward from a port side 22 of the fuselage 12 relative to the longitudinal centerline 14, while a second of such wings 20 extends laterally outward from a starboard side 24 of the fuselage 12 relative to the longitudinal centerline 14. Each wing 20 of the exemplary embodiment shown includes one or more leading edge flaps 26 and one or more trailing edge flaps 28. The aircraft 10 further includes a vertical stabilizer 30 having a rudder flap 32 for yaw control and a pair of horizontal stabilizers 34, each horizontal stabilizer 34 having an elevator flap 36 for pitch control. The fuselage 12 additionally includes an outer surface or skin 38. However, it should be understood that in other exemplary embodiments of the present disclosure, the aircraft 10 may additionally or alternatively include any other suitable stabilizer configuration that may or may not extend directly in the vertical direction V or the horizontal / lateral direction L.

[0035] Figure 1 and 2 The exemplary aircraft 10 of the present invention includes a propulsion system 100, referred to herein as “system 100”. The exemplary system 100 includes one or more aircraft engines and one or more electric propulsion engines. For example, the depicted embodiment includes a plurality of aircraft engines, each of which is configured to be mounted to the aircraft 10, such as to one of a pair of wings 20, and an electric propulsion engine. More specifically, for the depicted embodiment, the aircraft engines are configured as gas turbine engines, or more specifically, as turbofan jet engines 102, 104 that are attached to and suspended below the wings 20 in an underwing configuration. Additionally, the electric propulsion engines are configured to be mounted at the rear end of the aircraft 10, and thus the depicted electric propulsion engines may be referred to as “rear engines”. Further, the depicted electric propulsion engines are configured to inhale and consume air that forms a boundary layer on the fuselage 12 of the aircraft 10. Therefore, the depicted exemplary rear engine may be referred to as a boundary layer inhalation (BLI) fan 106. The BLI fan 106 is mounted to the aircraft 10 at a location aft of the wing 20 and / or jet engines 102, 104. Specifically, for the depicted embodiment, the BLI fan 106 is fixedly connected to the fuselage 12 at the rear end 18 such that the BLI fan 106 merges or blends with the tail at the rear end 18 and such that the meanline 15 extends therethrough. However, it should be understood that in other embodiments, the electric propulsion engine may be configured in any other suitable manner and may not necessarily be configured as a rear fan or a BLI fan.

[0036] Still reference Figure 1 and 2 In some embodiments, the propulsion system also includes one or more generators 108 operable with the jet engines 102, 104. For example, one or both of the jet engines 102, 104 may be configured to provide mechanical power to the generator 108 from a rotating shaft (e.g., an LP shaft or an HP shaft). Although schematically depicted outside the respective jet engines 102, 104, in some embodiments, the generator 108 may be positioned within the respective jet engines 102, 104. Additionally, the generator 108 may be configured to convert mechanical power into electrical power. For the depicted embodiment, the propulsion system 100 includes a generator 108 for each jet engine 102, 104, and also includes a power conditioner 109 and an energy storage device 110. The generator 108 may send electrical power to the power conditioner 109, which may convert the electrical power into an appropriate form and store the energy in the energy storage device 110 or send the electrical energy to the BLI fan 106. For the depicted embodiment, the generator 108, the power conditioner 109, the energy storage device 110, and the BLI fan 106 are all connected to an electrical bus 111, such that the generator 108 can be in electrical communication with the BLI fan 106 and / or the energy storage device 110, and such that the generator 108 can provide electrical power to one or both of the energy storage device 110 or the BLI fan 106. Thus, in such embodiments, the propulsion system 100 can be referred to as a gas-electric propulsion system.

[0037] However, it should be understood that Figure 1 and 2The aircraft 10 and propulsion system 100 depicted in the drawings are provided as examples only, and in other exemplary embodiments of the present disclosure, any other suitable aircraft 10 having a propulsion system 100 configured in any other suitable manner may be provided. For example, it should be understood that in various other embodiments, the BLI fan 106 may alternatively be positioned at any suitable location near the rear end 18 of the aircraft 10. Furthermore, in other embodiments, the electric propulsion engine may not be positioned at the rear end of the aircraft 10, and thus may not be configured as a "rear engine". For example, in other embodiments, the electric propulsion engine may be incorporated into the fuselage of the aircraft 10, and thus may be configured as a "pod engine" or a pod-mounted engine. Furthermore, in other embodiments, the electric propulsion engine may be incorporated into the wing of the aircraft 10, and thus may be configured as a "hybrid wing engine". Furthermore, in other embodiments, the electric propulsion engine may not be a boundary layer intake fan, but may be mounted at any suitable location on the aircraft 10 as a free stream intake fan (e.g., in an underwing mounted configuration, in a fuselage mounted configuration, in a tail mounted configuration, etc.). Furthermore, in other embodiments, propulsion system 100 may not include power conditioner 109 and / or energy storage device 110, for example, but rather generator 108 may be directly connected to the electric propulsion system.

[0038] Reference now Figure 3 , a schematic cross-sectional view of a propulsion engine according to an exemplary embodiment of the present disclosure is provided. In certain exemplary embodiments, the propulsion engine may be configured as a high bypass turbofan jet engine 200, referred to herein as "turbofan 200". It is noteworthy that in at least some embodiments, the jet engines 102, 104 may also be configured as high bypass turbofan jet engines. In various embodiments, turbofan 200 may represent jet engines 102, 104. However, optionally, in other embodiments, turbofan 200 may be incorporated into any other suitable aircraft 10 or propulsion system 100.

[0039] like Figure 3 As shown, the turbofan 200 defines an axial direction A (extending parallel to a longitudinal centerline 201 for reference), a radial direction R, and a circumferential direction C (extending around the axial direction A; not shown in FIG. Figure 3 ). Generally speaking, the turbofan 200 includes a fan section 202 and a turbine 204 disposed downstream of the fan section 202 .

[0040] The exemplary turbine 204 shown generally includes a substantially tubular outer casing 206 defining an annular inlet 208. The outer casing 206 surrounds, in series flow relationship: a compressor section including a supercharger or low pressure (LP) compressor 210 and a high pressure (HP) compressor 212; a combustion section 214; a turbine section including a high pressure (HP) turbine 216 and a low pressure (LP) turbine 218; and an injection exhaust nozzle section 220. The compressor section, combustion section 214, and turbine section together define a working air flow path 221 extending from the annular inlet 208 through the LP compressor 210, the HP compressor 212, the combustion section 214, the HP turbine section 216, the LP turbine section 218, and the injection nozzle exhaust section 220. A high pressure (HP) shaft or spool 222 drivingly connects the HP turbine 216 to the HP compressor 212. A low pressure (LP) shaft or spool 224 drivingly connects the LP turbine 218 to the LP compressor 210 .

[0041] For the depicted embodiment, the fan section 202 includes a variable pitch fan 226 having a plurality of fan blades 228 coupled to a disk 230 in a spaced apart manner. As shown, the fan blades 228 extend outwardly from the disk 230 generally in a radial direction R. Each fan blade 228 can rotate relative to the disk 230 about a pitch axis P because the fan blades 228 are operably coupled to a suitable actuation member 232, wherein the actuation member 232 is configured to collectively change the pitch of the fan blades 228. The fan blades 228, the disk 230, and the actuation member 232 can rotate together about the longitudinal axis 12 via the LP shaft 224 across a power gearbox 234. The power gearbox 234 includes a plurality of gears for stepping down the rotational speed of the LP shaft 224 to a more efficient rotating fan speed.

[0042] Still refer to Figure 3 In the exemplary embodiment of the present invention, the disk 230 is covered by a rotatable front hub 236 having an aerodynamic profile configured to facilitate airflow through the plurality of fan blades 228. Additionally, the exemplary fan section 202 includes an annular fan casing or outer nacelle 238 that circumferentially surrounds the fan 226 and / or at least a portion of the turbine 204. The nacelle 238 is supported relative to the turbine 204 by a plurality of circumferentially spaced outlet guide vanes 240. A downstream section 242 of the nacelle 238 extends outside of the turbine 204 to define a bypass airflow passage 244 therebetween.

[0043] Although not shown, various rotating components of the turbofan engine 10 (e.g., LP shaft 224, HP shaft 222, fan 202) may be supported by one or more oil-lubricated bearings. The illustrated turbofan engine 10 includes a lubrication system 245 for providing lubricating oil to one or more oil-lubricated bearings. In addition, the lubrication system 245 may include one or more heat exchangers for transferring heat from the lubricating oil through, for example, bypass air, exhaust air, or fuel.

[0044] Additionally, the exemplary turbofan 200 shown includes a motor 246 that is rotatable with the fan 226. Specifically, for the illustrated embodiment, the motor 246 is configured as a generator that is coaxially mounted to the LP shaft 224 (for the depicted embodiment, the LP shaft 224 also rotates the fan 226 through the power gear box 234) and rotatable with the LP shaft 224. As used herein, "coaxial" refers to axis alignment. However, it should be understood that in other embodiments, the axis of the motor 246 can be radially offset from the axis of the LP shaft 224, and can also be tilted relative to the axis of the LP shaft 224, so that the motor 246 can be at least partially positioned at any suitable position inside the working air flow path 221.

[0045] The motor 246 includes a rotor 248 and a stator 250. In certain exemplary embodiments, the rotor 248 and the stator 250 of the motor 246 are configured in substantially the same manner as the exemplary rotor and stator of the motor described below. It is worth noting that when the turbofan engine 200 is integrated into the above reference Figure 1 and Figure 5 In the propulsion system 100 described herein, the generator 108 may be operated in a manner similar to that described in the embodiment of the present invention. Figure 3 The motor 246 is configured in substantially the same manner.

[0046] However, it should also be understood that Figure 3 The exemplary turbofan engine 200 depicted in FIG. 2 is provided as an example only, and in other exemplary embodiments, the turbofan engine 200 may have any other suitable configuration. For example, in other exemplary embodiments, the turbofan engine 200 may be configured as a turboprop engine, a turbojet engine, a turbofan engine of a different configuration, or any other suitable gas turbine engine.

[0047] Reference now Figure 4 , depicting an electric machine 246 embedded within a gas turbine engine 200 according to an exemplary embodiment of the present disclosure. In certain exemplary embodiments, Figure 4 The electric machine 246 and gas turbine engine 200 depicted in the drawings may be used in the same manner as described above with reference to Figure 3The depicted exemplary electric machine 246 is configured in substantially the same manner as the turbofan engine 200. Thus, the same or similar numbers may refer to the same or similar parts.

[0048] More specifically, the electric machine 246 is coupled to a rotating component of the gas turbine engine 200 at a location at least partially inboard of the working air flow path 221 of the gas turbine engine 200 in the radial direction R. More specifically, in the depicted embodiment, the electric machine 246 is embedded within the turbine section of the gas turbine engine 200, and more specifically, is coupled to the LP shaft 224 of the gas turbine engine 200. Additionally, the electric machine 246 is at least partially positioned inside the turbine section or at least partially positioned aft of the turbine section in the axial direction A.

[0049] As depicted, motor 246 generally includes a rotor 248 and a stator 250. Rotor 248 is directly attached to LP shaft 224 such that rotor 248 can rotate with LP shaft 224. However, in other embodiments, rotor 248 can be attached to LP shaft 224 via one or more rotor connection members.

[0050] In contrast, stator 250 is attached to structural support member 256 via one or more stator connection members 254. In at least some exemplary embodiments, motor 246 may be a generator such that rotor 248 is driven by LP shaft 224. In such embodiments, rotation of rotor 248 relative to stator 250 may generate electricity, which may be transmitted via electrical bus 258, as will be discussed in greater detail below.

[0051] However, it should be understood that in other exemplary embodiments, the motor 246 may alternatively have any other suitable configuration. For example, in other embodiments, the motor 246 may include a rotor 248 located radially outside the stator 250 (e.g., as an outer rotor motor 246). Additionally, in certain embodiments, the motor 246 may operate as a motor, or may operate as both a motor and a generator. Further, the motor 246 may be mounted at any suitable location inside the working air flow path 221, within or at the rear of the turbine section. For example, in still other embodiments, the motor 246 may rotate with the high pressure shaft of the engine ( Figure 4 not depicted).

[0052] Additionally, in certain exemplary embodiments, the motor 246 may be configured as a permanent magnet motor including a plurality of permanent magnets (not shown). For these embodiments, the stator 250 may include one or more coils of electrically conductive wire (not shown). However, it should be understood that in other embodiments, the motor 246 may alternatively be configured as an electromagnetic motor including a plurality of electromagnets and active circuits, such as an induction motor, a switched reluctance motor, such as a synchronous AC motor, or any other suitable generator or motor.

[0053] Still refer to Figure 4 In the exemplary motor 246 of FIG. 1 , the structural support member 256 can be configured as part of an aft frame assembly extending from an aft frame strut 260. The aft strut 260 extends through the working air flow path 221 of the gas turbine engine 200 and is configured to provide structural support for the gas turbine engine 200. For the illustrated embodiment, the structural support member 256 also extends forward to support an aft engine bearing 262 that rotatably supports the LP shaft 224.

[0054] The stator connection member 254 may be an annular / cylindrical member extending from a structural support member 256 of the gas turbine engine 200. For the depicted embodiment, the stator connection member 254 further supports the rotation of the LP shaft 224 through one or more bearings. More specifically, the depicted gas turbine engine 200 further includes a front motor bearing 264, which is positioned in front of the motor 246 and is positioned between the LP shaft 224 and the stator connection member 254 in the radial direction R. Similarly, the rear motor bearing 266 is positioned behind the motor 246 and is positioned between the LP shaft 224 and the stator connection member 254 in the radial direction R. In particular, for the depicted embodiment, the front motor bearing 264 and the rear motor bearing 266 are both depicted as roller element bearings. However, in other embodiments, one or both are optionally configured as ball bearings or any other suitable bearings. For example, it should be appreciated that in other embodiments, the front motor bearing 264 and the rear motor bearing 266 may have any other suitable configurations and the present disclosure is not intended to be limited to the particular configuration depicted unless such limitations are added to the claims.

[0055] For the illustrated embodiment, the gas turbine engine 200 further defines an aft turbine sump 270. For the illustrated embodiment, the aft turbine sump 270 is at least partially defined by the structural support member 256 and the state connection member 254. The aft turbine sump 270 at least partially surrounds the aft engine bearing 262 for accommodating, for example, lubricating oil supplied by a lubricating oil supply system ( Figure 42; discussed below) to provide lubricating oil to the rear engine bearing 262. For the illustrated embodiment, the rear turbine sump 270 is fluidly bounded by a front sump seal 276 and by a front motor seal 278. The front sump seal 276 and the front motor seal 278 can maintain the provision of lubricating oil to the rear engine bearing 262 substantially within the rear turbine sump 270.

[0056] Of note, it will be further appreciated that in the illustrated embodiment, the motor 246 is further positioned within a motor compartment 280, which may be referred to as a motor sump, depending on the fluid provided thereto (e.g., cooling fluid discussed below). The motor compartment 280 is at least partially defined by the stator connection member 254 and the forward motor seal 278. Additionally, for the illustrated embodiment, the gas turbine engine 200 further includes an aft motor seal 280, further defining the motor compartment 280. The forward motor seal 278 and the aft motor seal 280 may substantially fluidly contain the fluid within the motor compartment 280.

[0057] However, it should be understood that in other exemplary embodiments, the arrangement of the bearings 264, 266 and the seals 278, 280 may be reversed such that the seals 278 and 280 are positioned closer to the motor 246 than the bearings 264, 266, respectively. With this configuration, the seals 278, 280 may substantially fluidly isolate the motor compartment 280 from, for example, the aft turbine sump 270. This configuration may be selected based on, for example, the fluid provided thereto (e.g., the cooling fluid discussed below).

[0058] As briefly discussed above, during operation of the gas turbine engine 200, the LP shaft 224 may rotate the rotor 248 of the electric machine 246, thereby allowing the electric machine 246 to function as a generator to produce electrical power. Additionally, the electric machine 246 is in electrical communication with—i.e., electrically connected to—an electrical bus 258. The electrical bus 258 may generally include a plurality of electrical wires, various power electronics, and converters, schematically represented as 282, etc. The electrical bus 258 may electrically connect the electric machine 246 to other aircraft power sources and exchange electrical power during operation in response to, for example, aircraft or engine controllers.

[0059] For the illustrated embodiment, the electrical bus 258 is electrically connected to the motor 246 at a location radially inward of the working air flow path 221. The electrical bus 258 includes one or more electrical wires, referred to for convenience as a single electrical wire 284, extending through the working air flow path 221 at a location within or behind the turbine section. More specifically, the electrical wire 284 includes a middle portion 286 extending through the working air flow path 221. The electrical bus 258 also includes a first terminal box 288 located outside the working air flow path 221 in the radial direction R and a second terminal box 290 located inside the working air flow path 221 in the radial direction R. The middle portion 286 extends from the first terminal box 288 to the second terminal box 290 through the working air flow path 221.

[0060] The illustrated exemplary gas turbine engine 200 further includes a cooling system 292 to help maintain the temperature of intermediate portion 286 of electrical bus 258 and electric machine 246 within a desired operating temperature range during operation of gas turbine engine 200 .

[0061] For example, it should be understood that each of the plurality of permanent magnets of the motor 246 (if included) defines a Curie temperature limit that may be less than the temperature within the working air flow path 221 extending through the turbine section of the gas turbine engine 200. The cooling system 292 of the gas turbine engine 200 may function to maintain the temperature of the motor 246, and more specifically each permanent magnet, below the Curie temperature limit of the plurality of permanent magnets. Further, the cooling system 292 may maintain the temperature of the motor 246 below a predetermined limit of the Curie temperature limit, for example, to increase the useful life of the motor 246. For example, in certain exemplary embodiments, the cooling system 292 of the gas turbine engine 200 may maintain the temperature of the motor 246 below a limit of at least about 50 degrees Fahrenheit (°F) of the Curie temperature limit, such as below a limit of at least about 75°F-100°F of the Curie temperature limit. Maintaining the temperature of the motor 246 below such a limit of the Curie temperature limit may further prevent any permanent magnet of the motor 246 from experiencing irreversible (or permanent) demagnetization, which may have a negative life impact on the motor.

[0062] Furthermore, during operation of a gas turbine engine 200 including an electric machine 246 according to an exemplary embodiment of the present disclosure, the electric machine 246 may be configured to generate a relatively large amount of electrical power, such as AC power. For example, in certain embodiments, the electric machine 246 may be configured to generate and deliver five hundred (500) volts ("V") or more of electrical power through the wires 284 of the electrical bus 258. For example, in certain embodiments, the electric machine 246 may be configured to generate and deliver six hundred (600) V or more of electrical power through the wires 284 of the electrical bus 258. This configuration may be achieved by the disclosed cooling system 292 for maintaining the temperature of the electric machine 246 within a certain operating temperature range, and / or by designing the intermediate portion 286 in a manner that allows the intermediate portion 286 of the electrical bus 258 to traverse the relatively high temperatures within the working air flow path 221 downstream of the combustion section of the gas turbine engine 200 while carrying a relatively high voltage.

[0063] With specific reference to the illustrated embodiment, the cooling system 292 includes a cooling fluid supply line 294 and a cooling fluid return line 296. A portion of the electrical bus 258 extending through the working air flow path 221, such as the middle portion 286 of the wire 284, is substantially embedded within the cooling fluid supply line 294, and another portion of the cooling fluid supply line 294 extending through the working air flow path 221 is substantially embedded within the cooling fluid return line 296.

[0064] More specifically, for Figure 4 In the illustrated embodiment, the portion of the electrical wire 284 extending through the working air flow path 221 is entirely embedded within the cooling fluid supply line 294 , and similarly, the portion of the cooling fluid supply line 294 extending through the working air flow path 221 is entirely embedded within the cooling fluid return line 296 .

[0065] In this manner, it should be understood that the electrical wires 284 are surrounded by the cooling fluid flow 298 through the cooling fluid supply line 294, such that the intermediate portion 286 of the electrical bus 258 that traverses the working air flow path 221 is not directly exposed to anything outside the cooling fluid supply line 294. Similarly, for the illustrated embodiment, the cooling fluid supply line 294 is surrounded by the cooling fluid flow 298 that is returned through the cooling fluid return line 296, such that the cooling fluid supply line 294 that traverses the working air flow path 221 is not directly exposed to anything outside the cooling fluid return line 296.

[0066] For example, briefly refer to Figure 5 and 6 , shows a close-up cross-sectional view of the cooling fluid supply line 294, the cooling fluid return line 296, and the intermediate portion 286 of the electrical bus 258. In particular, Figure 5A close-up schematic cross-sectional view of the assembly along the longitudinal direction of the assembly is provided, Figure 6 A close-up schematic cross-sectional view of the assembly along the transverse direction of the assembly is provided (along Figure 5 Line 6-6 in the figure).

[0067] In this way, the portion of the electrical bus 258 extending through the working air flow path 221 is very well isolated from the relatively high temperatures within the working air flow path 221, so that the wires 284 can carry the required amount of power through the working air flow path 221 and remain within the temperature limits of the materials. Further, the cooling fluid flow 298 through the cooling fluid supply line 294 is also isolated from the relatively high temperatures within the working air flow path 221, so that the cooling fluid flow 298 through the cooling fluid supply line 294 can cool, for example, the motor 246, which will be described in more detail below.

[0068] More specifically, as described above, the exemplary cooling system 292 includes a first terminal box 288 located outside the working air flow path 221 in the radial direction R and a second terminal box 290 located inside the working air flow path 221 in the radial direction R. The middle portion 286 of the electrical bus 258 extends from the first terminal box 288 to the second terminal box 290. At the first terminal box 288, the wires 284 of the electrical bus 258 are set to the inside of the cooling fluid supply line 294, and the cooling fluid supply line 294 is set to the inside of the cooling fluid return line 296. The embedded arrangement extends to the second terminal box 290, where the cooling fluid return line 296 branches and is fluidly connected to the motor compartment 280. The cooling fluid return line 296 can purge the cooling fluid in the motor compartment 280 for returning the cooling fluid to a position outside the working air flow path 221, as described below.

[0069] Also at the second terminal box 290, the cooling fluid supply line 294 extends to the motor 246, while the wires 284 of the electrical bus 258 are still embedded therein. Figure 7, a close-up schematic diagram of the motor 246 is provided, as well as a close-up schematic diagram of a portion of the electrical bus 258 and the cooling system 292. For the illustrated embodiment, the cooling fluid supply line 294 is in fluid communication with the motor heat exchanger 300, the motor 246, or both to cool the motor 246. More specifically, for the depicted exemplary embodiment, the motor 246 includes the motor heat exchanger 300, which is thermally coupled to the stator 250 of the motor 246, and also includes a motor terminal box 302 for receiving the cooling fluid supply line 294, wherein the wires 284 of the electrical bus 258 are positioned therein. The motor terminal box 302 separates the wires 284 from the interior of the cooling fluid supply line 294. The wires 284 are electrically coupled to the stator 250, and a cooling fluid flow 298 through the cooling fluid supply line 294 is provided to the motor heat exchanger 300. In the illustrated embodiment, the motor heat exchanger 300 includes a plurality of channels 304 that circumferentially surround at least a portion of the stator 250 (extending in a circumferential direction C). The cooling fluid flow 298 from the cooling fluid supply line 294 flows through these passages 304 to reduce the temperature of the stator 250 , which in turn reduces the temperature of the electric machine 246 .

[0070] For the illustrated embodiment, the motor heat exchanger 300 includes an inlet 306 and an outlet 308 for receiving the cooling fluid flow 298 from the motor terminal box 302. In the illustrated embodiment, the outlet 308 provides the cooling fluid flow 298 to the motor compartment 280 to be purged by the cooling system return line 296.

[0071] Additionally, or alternatively, in other exemplary embodiments, the outlet 308 of the motor heat exchanger 300 may be directly fluidly coupled to the cooling fluid return line 296, such as in Figure 7 Shown as dotted lines.

[0072] In one or more of these configurations, the cooling fluid flow 298 can further serve as a cooling medium for the front motor bearing 264 and the rear motor bearing 266 (see Figure 4 ) of a lubricant and / or heat exchange fluid. In this manner, it should be understood that in certain exemplary embodiments, the cooling fluid flow 298 may be a liquid cooling fluid flow, such as a lubricating oil flow.

[0073] However, in other exemplary embodiments, the cooling fluid may additionally or alternatively be a gaseous cooling fluid, such as air. Using this configuration, the air may not be used as a lubricant for any bearings. However, this may allow the cooling system 292 to cool the motor 246 without requiring additional structure or protection for the motor 246 to direct the cooling fluid flow. For example, in this configuration, the cooling fluid flow 298 from the cooling fluid supply line 294 may simply be directed to one or more aspects of the motor 246 to cool the motor 246.

[0074] Still refer to Figure 4 In the illustrated embodiment, the cooling system 292 is a closed-loop cooling system 292. For example, in the illustrated embodiment, the cooling fluid supply line 294 and the cooling fluid return line 296 are in series flow communication. For example, during typical operation, a cooling fluid flow 298 is provided to the first terminal box 288 via the cooling fluid supply line 294. Within the first terminal box 288, as described above, the cooling fluid supply line 294 is directed to a conduit embedded within the cooling fluid return line 296 extending through the working air flow path 221. The relatively cool cooling fluid flow 298 is then separated at the second terminal box 290 into a portion of the cooling fluid supply line 294 extending to the motor 246. The relatively cool cooling fluid flow 298 is then used to remove heat from the motor 246, reducing the temperature of the motor 246. After receiving heat from the motor 246, the relatively warm cooling fluid is provided to the cooling fluid return line 296 and reaches the second terminal box 290. At the second terminal box 290, the relatively warm cooling fluid is provided to a portion of the cooling fluid return line 296, which surrounds a portion of the cooling fluid return line 296 and extends through the working air flow path 221 (so that the relatively cool cooling fluid flow 298 in the cooling fluid supply line 294 is shielded from the high temperature of the working air flow path 221) to the first terminal box 288. At the first terminal box 288, the relatively warm cooling fluid is separated out to a separate cooling fluid return line 296. For the illustrated embodiment, the cooling portion 310 of the cooling system 292 is configured to receive cooling of the relatively warm cooling fluid from the cooling fluid return line 296, cool the relatively warm cooling fluid to return to the relatively cool cooling fluid, and provide the relatively cool cooling fluid to the cooling fluid supply line 294. The closed loop flow can then repeat.

[0075] In certain exemplary embodiments, cooling system 292 also includes a cooling portion 310. Cooling portion 310 of cooling system 292 may be, for example, a heat exchanger for reducing the temperature of a cooling fluid. For example, the heat exchanger may be a surface cooler configured to utilize air flow over cowling 206 of the turbine, an air-to-oil cooler heat exchanger, an oil-to-oil cooler heat exchanger, a heat exchanger with an integrated heat bus, and the like.

[0076] However, it should be understood that the cooling system 292 may have any other suitable configurations compared to other exemplary embodiments. Figure 8 , a schematic diagram of a gas turbine engine 200 having an electrical system and a cooling system 292 is provided according to another exemplary embodiment of the present disclosure. Figure 8 The exemplary gas turbine engine 200, electrical system, and cooling system 292 depicted may be similar to those described above with reference to Figures 4 to 7The depicted exemplary gas turbine engine 200 , electrical system, and cooling system 292 are configured in a similar manner.

[0077] For example, the depicted exemplary gas turbine engine 200 includes an electrical system having an electric machine 246 embedded within the turbine section of the gas turbine engine 200 and an electrical bus electrically coupled to the electric machine 246 and having electrical wires 284 extending through the working air flow path 211 of the gas turbine engine 200 within the turbine section or downstream of the turbine section. Additionally, the exemplary gas turbine engine 200 includes a cooling fluid supply line 294 in a cooling fluid return line 296, wherein a portion of the electric machine 246 extending to the air flow path is substantially embedded within the cooling fluid supply line 294 and a portion of the cooling fluid supply line 294 extending to the working air flow path 221 is substantially embedded within the cooling fluid return line 296.

[0078] Further, for the illustrated embodiment, the exemplary cooling system 292 further includes a cooling portion 310, which includes a heat exchanger 312. In certain exemplary embodiments, as in Figure 8 As schematically depicted in FIG. 1 , heat exchanger 312 may be an air cooled heat exchanger that utilizes airflow over cowling 206 of the turbine.

[0079] However, for the illustrated embodiment, the cooling system 292 further includes an expansion device located downstream of the portion of the cooling fluid return line 296 extending through the working air flow path 221 and upstream of the cooling portion 310, or more precisely, upstream of the heat exchanger 312. For the illustrated embodiment, the expansion device is a turbine 314, and the gas turbine engine 200 further includes an auxiliary motor 316 driven by the turbine 314. In this way, the cooling system 292 can capture heat from, for example, the motor 246 and use this heat to generate more electricity. The expanded cooling fluid from the turbine 314 can be provided to the heat exchanger 312, where the temperature can be further reduced. In this way, the cooling system 292 can generally operate according to the Rankine cycle, in which the hot components inside the working air flow path 221 operate to provide heat and work to the cycle. The turbine 314 and the heat exchanger 312 are operable to reduce the temperature of the working fluid.

[0080] With such a configuration, it should be understood that the cooling fluid may be a single-phase cooling fluid, such as a liquid (e.g., lubricating oil), a supercritical fluid (e.g., supercritical CO2), etc. Additionally or alternatively, the cooling fluid may be a phase-changing fluid configured to change between a gas phase and a liquid phase based on the cycle of the cooling system 292. In one or more of these configurations, the cooling system 292 may additionally include a compressor, may not include the auxiliary motor 316, etc.

[0081] Further, in still other exemplary embodiments, any other suitable configurations may be provided for the gas turbine engine 200, the electrical system, and / or the cooling system 292. For example, referring now to Fig. 9 , a gas turbine engine 200 , an electrical system, and a cooling system 292 according to another exemplary embodiment of the present disclosure are provided. Fig. 9 The exemplary embodiments can be described with reference to the above Figures 3 to 8 One or more of the described exemplary embodiments may be configured in a similar manner.

[0082] from Fig. 9 As will be further appreciated from the embodiment depicted in FIG. 2 , the gas turbine engine 200 further includes a lubricating oil system 318 for providing a flow of lubricating oil to, for example, the aft engine bearing 262 within the aft turbine sump 270. In the illustrated embodiment, the cooling system 292 is integrated with the lubricating oil system 318 such that the cooling fluid flow 298 through the cooling system 292 has a dual function of serving as a cooling fluid for the motor 246 and serving as a lubricating oil / cooling oil for the lubricating oil system 318. In particular, for the illustrated embodiment, the cooling system 292 includes a cooling system heat exchanger 312 and the lubricating oil system 318 includes a lubricating oil tank 320. For the illustrated embodiment, the cooling system heat exchanger 312 is thermally coupled to the lubricating oil tank 320. In this manner, the cooling system heat exchanger 312 can operate to reduce the temperature of the lubricating oil tank 320 and / or the temperature of the lubricating oil within the lubricating oil tank 320 (which serves as the cooling fluid for the cooling system 292).

[0083] Still reference Fig. 9 For the illustrated embodiment, the cooling fluid supply line 294 is configured to provide a cooling fluid flow 298 to the motor 246 and one or more bearings and / or reservoirs and the cooling fluid return line 296 is configured to return the cooling fluid flow 298 from the motor 246 and from one or more bearings and / or reservoirs (e.g., operating as a lube oil purge line). More specifically, for the illustrated embodiment, the cooling fluid supply line 294 is configured to provide a cooling fluid flow 298 to the motor 246 and the aft turbine reservoir 270 and the cooling fluid return line 296 is configured to purge the cooling fluid 298 from the motor and from the aft turbine reservoir 270.

[0084] More specifically, for Fig. 9In the embodiment of the present invention, the cooling system 292 further includes a third terminal box, which is configured as an intermediate terminal box 322 in the embodiment shown, which is located inside the working air flow path 221 in the radial direction R and between the first terminal box 288 and the second terminal box 290. The cooling system 292 further includes a first supply branch 324 of the cooling fluid supply line 294 and a first return branch 326 of the cooling fluid return line 296, each of which is fluidly coupled to the intermediate terminal box 322. At the intermediate terminal box 322, the first supply branch 324 of the cooling fluid supply line 294 receives a relatively cool cooling fluid flow from the cooling fluid supply line 294. The first supply branch 324 of the cooling fluid supply line 294 is further in fluid communication with the rear turbine tank 270 for providing relatively cool cooling fluid to the rear turbine tank 270. Similarly, at the intermediate terminal box 322, the first return branch 326 of the cooling fluid return line 296 is fluidly coupled to the cooling fluid return line 296 flowing back to the lubrication oil tank. The first return branch 326 of the cooling fluid return line 296 is further fluidly coupled to the rear turbine sump 270 for purging relatively hot cooling fluid from the rear turbine sump 270 and returning the relatively hot cooling fluid to the lubrication oil tank 320 via the cooling fluid return line 296.

[0085] However, it should be understood that the cooling system 292 and the electrical bus 258 may have any other suitable configurations as compared to other exemplary embodiments. Fig.10 , a schematic diagram of a gas turbine engine 200 having an electrical system and a cooling system 292 is provided according to another exemplary embodiment of the present disclosure. Fig.10 The exemplary gas turbine engine 200, electrical system, and cooling system 292 depicted in FIG. 2 may be described with reference to FIG. Figures 4 to 9 One or more of the depicted exemplary gas turbine engine 200 , electrical system, and cooling system 292 are configured in a similar manner.

[0086] However, for Fig.10 In the exemplary embodiment, the electrical bus 258 of the power system includes a first wire 284-1 and a second wire 284-2 extending through the turbine flow path 221 to the motor 246. The first wire 284-1 and the second wire 284-2 may be positive and negative wires, or any other suitable wire configuration.

[0087] In addition, for Fig.10, the cooling system 292 includes a cooling fluid supply line 294 and a cooling fluid return line 296. However, for the illustrated embodiment, the portion of the cooling fluid supply line 294 that extends through the turbine flow path 221 is not embedded within the cooling fluid return line 296. Instead, for the depicted embodiment, the cooling fluid supply line 294 extends through the turbine flow path 221 within the first strut 260-1 and the cooling fluid return line 296 extends through the turbine flow path 221 within the second strut 260-2. In addition, a portion of the first electrical wire 284-1 that extends through the turbine flow path 221 is embedded within the cooling fluid supply line 294, and similarly, a portion of the second electrical wire 284-2 that extends through the turbine flow path 221 is embedded within the cooling fluid return line 296. In this manner, both the first electrical wire 284-1 and the second electrical wire 284-2 are shielded from relatively high temperatures within the turbine flow path 221 within or downstream of the turbine section of the gas turbine engine 200. Further, with this configuration, the cooling fluid supply line 294 and the cooling fluid return line 296 and the combination of the wires 284-1, 284-2 can extend through a smaller cross-sectional space (e.g., through a smaller strut 260), thereby allowing a smaller strut with less interference (e.g., resistance) with the airflow through the turbine flow path 221.

[0088] It should be understood that although Fig.10 The embodiment of FIG. 2 shows a single cooling fluid supply line 294 and a single cooling fluid return line 296 , but the cooling system may include multiple of these lines, spaced apart from the other buckets along any suitable number of struts 260 .

[0089] This written description uses examples to disclose aspects of the invention, including the best mode, and also to enable those skilled in the art to practice aspects of the invention, including making and using any devices or systems and performing any combined methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0090] Further aspects and advantages may be derived from one or more configurations of the present disclosure in the following clauses:

[0091] A gas turbine engine defines a radial direction and an axial direction, the gas turbine engine comprising: a compressor section and a turbine section, the compressor section and the turbine section are arranged in a series flow sequence, the compressor section and the turbine section together defining a working air flow path; a rotating component, the rotating component can rotate together with at least a portion of the compressor section and at least a portion of the turbine section; an electrical system, the electrical system comprising an electric motor and an electrical bus, the electric motor is coupled to the rotating component at least partially inside the working air flow path in a radial direction, the electrical bus is electrically coupled to the electric motor, the electrical bus comprises an electrical wire extending through the working air flow path within or downstream of the turbine section; and a cooling system, the cooling system comprising a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wire extending through the working air flow path is substantially embedded in the cooling fluid supply line, and wherein a portion of the cooling fluid supply line extending through the working air flow path is substantially embedded in the cooling fluid return line.

[0092] A gas turbine engine according to one or more of these clauses, wherein a portion of the electrical wires extending through the working air flow path are fully embedded within the cooling fluid supply line.

[0093] A gas turbine engine according to one or more of these clauses, wherein a portion of the cooling fluid supply line extending through the working air flow path is fully embedded within the cooling fluid return line.

[0094] A gas turbine engine according to one or more of these clauses, wherein the cooling fluid supply line is in fluid communication with the motor heat exchanger, the motor, or both, for cooling the motor.

[0095] The gas turbine engine according to one or more of these clauses, wherein the cooling system is a closed loop cooling system.

[0096] The gas turbine engine according to one or more of these clauses, wherein the cooling fluid supply line and the cooling fluid return line are in series flow communication.

[0097] A gas turbine engine according to one or more of these clauses, wherein the cooling system further comprises an expansion device located downstream of a portion of the cooling fluid return line extending through the working air flow path and a cooling portion located downstream of the expansion device.

[0098] A gas turbine engine according to one or more of these clauses, wherein the expansion device is a turbine, and wherein the gas turbine engine further comprises an auxiliary electrical machine driven by the turbine.

[0099] The gas turbine engine according to one or more of these clauses, wherein the cooling portion includes a heat exchanger for receiving heat from a cooling fluid flow through the cooling system.

[0100] A gas turbine engine according to one or more of these clauses, wherein the cooling system is integrated with a lubrication oil system of the gas turbine engine, and wherein the cooling fluid supply line is configured to provide a cooling fluid flow to the electric machine and a sump located inside the working air flow path.

[0101] The gas turbine engine according to one or more of these clauses, wherein the cooling fluid return line is a lubrication oil sweep line.

[0102] The gas turbine engine according to one or more of these clauses, wherein the lubricating oil system further comprises a lubricating oil sump, and wherein the cooling system comprises a heat exchanger for cooling the lubricating oil thermally coupled to the lubricating oil sump.

[0103] A gas turbine engine according to one or more of these clauses, wherein the cooling system utilizes a gaseous cooling fluid or a liquid cooling fluid.

[0104] A gas turbine engine according to one or more of these clauses, wherein the cooling system utilizes a phase change cooling fluid.

[0105] A gas turbine engine defines a radial direction and an axial direction, the gas turbine engine comprising: a compressor section and a turbine section, the compressor section and the turbine section are arranged in a series flow sequence, the compressor section and the turbine section together defining a working air flow path; a rotating component, the rotating component can rotate together with at least a portion of the compressor section and at least a portion of the turbine section; an electrical system, the electrical system comprising an electric motor and an electrical bus, the electric motor is coupled to the rotating component at least partially inside the working air flow path in a radial direction, the electrical bus is electrically coupled to the electric motor, the electrical bus comprises an electrical wire extending through the working air flow path within or downstream of the turbine section; and a cooling system, the cooling system comprising a cooling fluid line, wherein a portion of the electrical wire extending through the working air flow path is substantially embedded within the cooling fluid line, and wherein the cooling fluid line extends from a position outside the working air flow path in a radial direction to a position inside the working air flow path in a radial direction, and wherein the cooling fluid line is in fluid communication with a cavity surrounding the electric motor.

[0106] The gas turbine engine according to one or more of these clauses, wherein the cooling fluid line is a cooling fluid supply line configured to provide a cooling fluid flow to a cavity surrounding the electric machine.

[0107] A gas turbine engine according to one or more of these clauses, wherein the electrical wire is a first electrical wire, wherein the electrical bus further includes a second electrical wire extending through a working air flow path within or downstream of the turbine section, wherein the cooling system further includes a cooling fluid return line, and wherein the second electrical wire is substantially embedded within the cooling fluid return line.

[0108] A gas turbine engine according to one or more of these clauses, wherein the gas turbine engine comprises a first airfoil and a second airfoil, the first airfoil and the second airfoil extending through a working gas flow path within or downstream of a turbine section and spaced apart in a circumferential direction of the gas turbine engine, and wherein a cooling fluid supply line extends through the first airfoil and a cooling fluid return line extends through the second airfoil.

[0109] An accessory system for a gas turbine engine, the gas turbine engine defining a radial direction and including a compressor section and a turbine section arranged in a series flow sequence and a rotating component capable of rotating together with at least a portion of the compressor section and at least a portion of the turbine section, the compressor section and the turbine section together defining a working air flow path, the accessory system comprising: an electrical system, the electrical system comprising an electric motor and an electrical bus, the electric motor being configured to be coupled to the rotating component at least partially inside the working air flow path in a radial direction, the electrical bus being electrically coupled to the electric motor and comprising an electrical wire configured to extend through the working air flow path within or downstream of the turbine section; and a cooling system, the cooling system comprising a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wire configured to extend through the working air flow path is substantially embedded within the cooling fluid supply line, and wherein a portion of the cooling fluid supply line configured to extend through the working air flow path is substantially embedded within the cooling fluid return line.

[0110] The accessory system of one or more of these clauses, wherein the cooling fluid supply line is in fluid communication with the motor heat exchanger, the motor, or both for cooling the motor.

Claims

1. A gas turbine engine, defining a radial direction and an axial direction, characterized in that: The gas turbine engine comprises: a compressor section and a turbine section, the compressor section and the turbine section arranged in a series flow sequence, the compressor section and the turbine section together defining a working air flow path; a rotating component rotatable with at least a portion of the compressor section and at least a portion of the turbine section; an electrical system including an electric machine coupled to the rotating component at least partially inside the working air flow path in the radial direction, and an electrical bus electrically coupled to the electric machine, the electrical bus including electrical wires extending through the working air flow path within or downstream of the turbine section; and A cooling system comprising a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wire extending through the working air flow path is substantially embedded within the cooling fluid supply line, and wherein a portion of the cooling fluid supply line extending through the working air flow path is substantially embedded within the cooling fluid return line.

2. The gas turbine engine according to claim 1, characterized in that The portion of the electrical wires extending through the working air flow path is entirely embedded within the cooling fluid supply line.

3. The gas turbine engine according to claim 2, characterized in that The portion of the cooling fluid supply line extending through the working air flow path is entirely embedded within the cooling fluid return line.

4. The gas turbine engine according to claim 1, characterized in that The cooling fluid supply line is in fluid communication with the motor heat exchanger, the motor, or both for cooling the motor.

5. The gas turbine engine according to claim 1, characterized in that The cooling system is a closed-loop cooling system.

6. The gas turbine engine according to claim 5, characterized in that The cooling fluid supply line and the cooling fluid return line are in series flow communication.

7. The gas turbine engine according to claim 5, characterized in that The cooling system further includes an expansion device downstream of the portion of the cooling fluid return line extending through the working air flow path and a cooling portion downstream of the expansion device.

8. The gas turbine engine according to claim 7, characterized in that The expansion device is a turbine, and wherein the gas turbine engine further comprises an auxiliary electric machine driven by the turbine.

9. The gas turbine engine according to claim 5, characterized in that The cooling portion includes a heat exchanger for receiving heat from a cooling fluid flowing through the cooling system.

10. The gas turbine engine according to claim 1, characterized in that The cooling system is integrated with a lubrication oil system of the gas turbine engine, and wherein the cooling fluid supply line is configured to provide a cooling fluid flow to the electric machine and a sump located inside the working air flow path.

11. The gas turbine engine according to claim 10, characterized in that The cooling fluid return line is a lubricating oil sweep line.

12. The gas turbine engine according to claim 10, characterized in that The lubricating oil system further comprises a lubricating oil tank, and wherein the cooling system comprises a heat exchanger for cooling the lubricating oil thermally coupled to the lubricating oil tank.

13. The gas turbine engine according to claim 1, characterized in that The cooling system utilizes a gaseous cooling fluid or a liquid cooling fluid.

14. The gas turbine engine according to claim 1, characterized in that The cooling system utilizes a phase change cooling fluid.

15. A gas turbine engine, defining a radial direction and an axial direction, characterized in that: The gas turbine engine comprises: a compressor section and a turbine section, the compressor section and the turbine section arranged in a series flow sequence, the compressor section and the turbine section together defining a working air flow path; a rotating component rotatable with at least a portion of the compressor section and at least a portion of the turbine section; an electrical system including an electric machine coupled to the rotating component at least partially inside the working air flow path in the radial direction, and an electrical bus electrically coupled to the electric machine, the electrical bus including electrical wires extending through the working air flow path within or downstream of the turbine section; and A cooling system comprising a cooling fluid line, wherein a portion of the electrical wire extending through the working air flow path is substantially embedded in the cooling fluid line, and wherein the cooling fluid line extends from a position outside the working air flow path along the radial direction to a position inside the working air flow path along the radial direction, and wherein the cooling fluid line is in fluid communication with a cavity surrounding the motor.

16. The gas turbine engine according to claim 15, characterized in that The cooling fluid line is a cooling fluid supply line configured to provide a cooling fluid flow to the cavity surrounding the electric machine.

17. The gas turbine engine according to claim 16, characterized in that The electrical wire is a first electrical wire, wherein the electrical bus further includes a second electrical wire extending through the working air flow path within or downstream of the turbine section, wherein the cooling system further includes a cooling fluid return line, and wherein the second electrical wire is substantially embedded within the cooling fluid return line.

18. The gas turbine engine according to claim 17, characterized in that The gas turbine engine comprises a first airfoil and a second airfoil, the first airfoil and the second airfoil extending through the working air flow path within or downstream of the turbine section and spaced apart in a circumferential direction of the gas turbine engine, and wherein the cooling fluid supply line extends through the first airfoil and the cooling fluid return line extends through the second airfoil.

19. An accessory system for a gas turbine engine, the gas turbine engine defining a radial direction and comprising a compressor section and a turbine section arranged in a series flow sequence and a rotating component capable of rotating together with at least a portion of the compressor section and at least a portion of the turbine section, the compressor section and the turbine section together defining a working air flow path, characterized in that The accessory system includes: an electrical system including an electric machine configured to be coupled to the rotating component at least partially inside the working air flow path in the radial direction, and an electrical bus electrically coupled to the electric machine and including electrical wires configured to extend through the working air flow path within or downstream of the turbine section; and A cooling system comprising a cooling fluid supply line and a cooling fluid return line, wherein a portion of the electrical wire configured to extend through the working air flow path is substantially embedded within the cooling fluid supply line, and wherein a portion of the cooling fluid supply line configured to extend through the working air flow path is substantially embedded within the cooling fluid return line.

20. The accessory system of claim 19, wherein: The cooling fluid supply line is in fluid communication with the motor heat exchanger, the motor, or both for cooling the motor.

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