Stator for an electric machine

Abstract

A stator for an electric machine includes a stator core defining slots extending from a first end to a second end in an axial direction; an electric wire disposed in the groove; a coolant tube disposed in the slot and extending from a first end to a second end in an axial direction, the coolant tube extending from a tube inlet to a tube outlet; and a thermally conductive potting material disposed in the slot between the coolant tube, the wire, and the stator core.

Description

Technical Field

[0001] The present disclosure relates to gas turbine engines, and more particularly, to cooling arrangements in gas turbine engines. Background Art

[0002] A typical aircraft propulsion system includes one or more gas turbine engines. For some propulsion systems, the gas turbine engine typically includes a fan and a core arranged in flow communication with each other. In addition, the core of the gas turbine engine typically 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, where one or more axial flow compressors gradually compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and combusted in the combustion section to provide combustion gases. The combustion gases are transported from the combustion section to the turbine section. The combustion gas flow through the turbine section drives the turbine section and is then transported through the exhaust section to, for example, the atmosphere.

[0003] Incorporating electric motors (e.g., generators) into propulsion engines to generate electrical power from the mechanical energy produced by the propulsion engines can enhance the performance of aircraft. For example, the electricity generated by the electric motors can be used to operate auxiliary propulsion devices (e.g., electric fans, electric motors, etc.) to supplement the thrust provided by the turbine engines. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0005] Figure 1 is a cross-sectional view of an exemplary gas turbine engine.

[0006] Figure 2 yes Figure 1 A perspective view of an exemplary stator of an exemplary gas turbine engine electric machine.

[0007] Figure 3 yes Figure 2 A magnified view of a portion of the stator showing the coolant tubes.

[0008] Figure 4 yes Figure 2 A partial enlarged view of the stator showing the coolant flow through Figure 3 coolant pipes.

[0009] Figure 5 is a perspective view of another exemplary stator.

[0010] Figure 6 yes Figure 5 A magnified view of a portion of the stator showing the coolant tubes.

[0011] Figure 7 yes Figure 2 A partial enlarged view of the stator showing the coolant flow through Figure 6 coolant pipes.

[0012] Figure 8 is a block diagram of an exemplary method for forming an electric machine. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to the present embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and the description have been used to refer to like or similar parts of the disclosure.

[0014] As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Furthermore, unless expressly stated otherwise, all embodiments described herein should be considered exemplary.

[0015] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0016] The terms "upstream" and "downstream" refer to relative directions of fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, while "downstream" refers to the direction toward which the fluid is flowing.

[0017] The present disclosure generally relates to apparatus for cooling electric machines in gas turbine engines, and methods for forming such apparatus. During operation, electric machines, such as motors and generators, generate heat. This heat can interfere with the operation of the electric machine, for example by increasing the resistance of the wiring, thereby weakening the magnetic field generated by the wiring. Thermal management to dissipate this heat can improve the efficiency and service life of the electric machine.

[0018] Liquid coolant can provide heat transfer via convection, while solid heat sinks provide heat transfer via conduction. Liquid coolant is provided in tubes within the stator to dissipate heat from the wires. Applying a potting material with high thermal conductivity to the stator ends further dissipates heat from the wires. By combining convective heat transfer from the coolant with conductive heat transfer from the potting material, overall heat dissipation from the wires is increased, and the efficiency of the motor is improved.

[0019] Now refer to Figure 1 , shows a schematic cross-sectional view of a gas turbine engine according to an example embodiment of the present disclosure. Specifically, Figure 1 An aviation three-stream turbofan engine is provided, referred to herein as "three-stream engine 100." Figure 1The three-flow engine 100 can be mounted to an aircraft (e.g., a fixed-wing aircraft) and can generate thrust for propelling the aircraft. The three-flow engine 100 is a "three-flow engine" because its architecture provides three different flows that generate thrust airflow during operation.

[0020] For reference, the three-stream engine 100 defines an axial direction A, a radial direction R, and a circumferential direction C. Furthermore, the three-stream engine 100 defines an axial centerline or longitudinal axis 112 extending along the axial direction A. Generally, the axial direction A extends parallel to the longitudinal axis 112, the radial direction R extends outwardly from and inwardly to the longitudinal axis 112 in a direction orthogonal to the axial direction A, and the circumferential direction extends three hundred and sixty degrees (360°) about the longitudinal axis 112. The three-stream engine 100 extends between a front end 114 and a rear end 116, e.g., along the axial direction A.

[0021] The three-stream engine 100 includes a core engine 118 and a fan section 150 positioned upstream thereof. Generally, the core engine 118 includes a compressor section, a combustion section, a turbine section, and an exhaust section in a series flow order. Specifically, as shown in FIG. Figure 1 As shown, the core engine 118 includes an engine core 120 and a core cowl 122 annularly surrounding the engine core 120. The engine core 120 and the core cowl 122 define an annular core inlet 124. The core cowl 122 also surrounds and supports a supercharger or low-pressure compressor 126 for pressurizing air entering the core engine 118 through the core inlet 124. A high-pressure, multi-stage, axial-flow compressor (hereinafter referred to as the high-pressure compressor 128) receives the pressurized air from the low-pressure compressor 126 and further increases the pressure of the air. The pressurized air flows downstream to the combustor 130, where fuel is injected into the pressurized air flow and ignited to increase the temperature and energy level of the pressurized air.

[0022] The high-energy combustion products flow downstream from the combustor 130 to a high-pressure turbine 132. The high-pressure turbine 132 drives the high-pressure compressor 128 via a first shaft, or high-pressure shaft 136. In this regard, the high-pressure turbine 132 is drivingly coupled to the high-pressure compressor 128. The high-energy combustion products then flow to a low-pressure turbine 134. The low-pressure turbine 134 drives the low-pressure compressor 126, components of the fan section 150, and the electric motor 200 via a second shaft, or low-pressure shaft 138. Specifically, the high-energy combustion products drive the turbine blades 135 of the low-pressure turbine 134. In this regard, the low-pressure turbine 134 is drivingly coupled to the low-pressure compressor 126, components of the fan section 150, and the electric motor 200. In this exemplary embodiment, the low-pressure shaft 138 is coaxial with the high-pressure shaft 136. After driving each of the turbines 132, 134, the combustion products exit the core engine 118 through the core exhaust nozzle 140 to generate propulsive thrust. Thus, the core engine 118 defines a core flow path or core duct 142 extending between the core inlet 124 and the core exhaust nozzle 140. The core duct 142 is an annular duct positioned generally inwardly of the core cover 122 in the radial direction R.

[0023] The fan section 150 includes a primary fan 152. Figure 1 In the illustrated embodiment, the primary fan 152 is an open rotor or non-ducted primary fan 152. However, in other embodiments, the primary fan 152 may be ducted, for example, by a fan housing or nacelle circumferentially surrounding the primary fan 152. As shown, the primary fan 152 includes an array of fan blades 154 ( Figure 1 Only one is shown). Fan blades 154 are rotatable, for example, about longitudinal axis 112. As described above, primary fan 152 is drivingly coupled to low pressure turbine 134 via LP shaft 138. Primary fan 152 may be directly coupled to LP shaft 138, for example, in a direct drive configuration. Alternatively, as Figure 1 As shown, the primary fan 152 may be coupled to the LP shaft 138 via a reduction gearbox 155 , such as in an indirect drive or gear drive configuration.

[0024] Furthermore, fan blades 154 can be arranged at equal intervals about longitudinal axis 112. Each fan blade 154 has a root and a tip and a span defined therebetween. Each fan blade 154 defines a central blade axis 156. For this embodiment, each fan blade 154 of primary fan 152 can rotate about its respective central blade axis 156, e.g., in unison with one another. One or more actuators 158 can be controlled to cause fan blades 154 to pitch about their respective central blade axis 156. However, in other embodiments, each fan blade 154 can be fixed or unable to pitch about its central blade axis 156.

[0025] The fan section 150 also includes a fan guide vane array 160 including fan guide vanes 162 ( Figure 1 For this embodiment, the fan guide vanes 162 are not rotatable about the longitudinal axis 112. Each fan guide vane 162 has a root and a tip and a span defined therebetween. The fan guide vanes 162 may be as follows: Figure 1 164 . The fan guide vanes 162 are shown as not obscured, or may be obscured, for example, by an annular shroud spaced outwardly from the tips of the fan guide vanes 162 in a radial direction R. Each fan guide vane 162 defines a central blade axis 164. For this embodiment, each fan guide vane 162 of the fan guide vane array 160 is rotatable about its respective central blade axis 164, for example, in unison with one another. One or more actuators 166 may be controlled to cause the fan guide vanes 162 to pitch about their respective central blade axis 164. However, in other embodiments, each fan guide vane 162 may be fixed or unable to pitch about its central blade axis 164. The fan guide vanes 162 are mounted to a fan shroud 170.

[0026] The fan shroud 170 annularly surrounds at least a portion of the core shroud 122 and is generally positioned outside the core shroud 122 in the radial direction R. Specifically, a downstream section of the fan shroud 170 extends above a front portion of the core shroud 122 to define a fan flow path or fan duct 172. Incoming air may enter the fan duct 172 through a fan duct inlet 176 and may be discharged through a fan exhaust nozzle 178 to generate propulsive thrust. The fan duct 172 is an annular duct that is generally positioned outside the core duct 142 in the radial direction R. The fan shroud 170 and the core shroud 122 are connected together and are formed by a plurality of substantially radially extending, circumferentially spaced struts 174 ( Figure 1 Each strut 174 has an aerodynamic profile to guide the air flowing therethrough. In addition to struts 174, other struts may be used to connect and support the fan shroud 170 and / or the core shroud 122.

[0027] The three-stream engine 100 further defines or includes an inlet duct 180. The inlet duct 180 extends between the engine inlet 182 and the core inlet 124 / fan duct inlet 176. The engine inlet 182 is generally defined at the front end of the fan cowl 170 and is positioned between the primary fan 152 and the fan guide vanes 162 along the axial direction A. The inlet duct 180 is an annular duct positioned inside the fan cowl 170 along the radial direction R. Air flowing downstream along the inlet duct 180 is divided (but not necessarily evenly) by the nose of the splitter 144 of the core cowl 122 into the core duct 142 and the fan duct 172. The inlet duct 180 is wider than the core duct 142 along the radial direction R. The inlet duct 180 is also wider than the fan duct 172 along the radial direction R.

[0028] As shown, the fan section 150 further includes a mid-fan 190. The mid-fan 190 includes an array of mid-fan blades 192 ( Figure 1 Only one is shown in FIG. 1 ). The middle fan blades 192 are rotatable, for example, about the longitudinal axis 112. The middle fan 190 is drive-coupled to the low-pressure turbine 134 via the LP shaft 138. The middle fan blades 192 may be arranged at equal circumferential spacing about the longitudinal axis 112. Each middle fan blade 192 has a root 194 and a tip 196 and a span defined therebetween. In addition, each middle fan blade 192 has a leading edge 198 and a trailing edge 199. The middle fan blades 192 are annularly surrounded or ducted by the fan cover 170. In this regard, the middle fan 190 is positioned inside the fan cover 170 in the radial direction R. In addition, for this example embodiment, the middle fan 190 is positioned within the inlet duct 180 upstream of the core duct 142 and the fan duct 172.

[0029] Thus, the air flowing through the inlet duct 180 flows over the middle fan blades 192 and is accelerated downstream thereof, particularly at the tips 196 of the middle fan blades 192. At least a portion of the air accelerated by the middle fan blades 192 flows into the fan duct 172 and is ultimately discharged through the fan exhaust nozzle 178 to generate propulsive thrust. In addition, at least a portion of the air accelerated by the middle fan blades 192 flows into the core duct 142 and is ultimately discharged through the core exhaust nozzle 140 to generate propulsive thrust. Typically, the middle fan 190 is a compression device positioned downstream of the engine inlet 182. The middle fan 190 is operable to accelerate air into the fan duct 172 or the secondary bypass passage.

[0030] However, it should be understood that the three-stream engine 100 is provided by way of example only. In other exemplary embodiments, the three-stream engine 100 may have any other configuration. For example, in other exemplary embodiments, the engine core 120 may have any other number and arrangement of shafts, spools, compressors, turbines, etc. In addition, in other exemplary embodiments, the three-stream engine 100 may alternatively be configured as a ducted turbofan engine (including an outer nacelle surrounding the primary fan 152 and a portion of the engine core 120); a direct drive gas turbine engine (which may not include a reduction gearbox, such as the reduction gearbox 155); a fixed pitch gas turbine engine (which may not include a variable pitch fan, such as the primary fan 152); a dual-flow gas turbine engine (which may not include a fan duct 172); and the like.

[0031] In addition, for Figure 1 In the illustrated embodiment, the three-stream engine 100 includes an electric motor operatively coupled to its rotating components. In this regard, the three-stream engine 100 is an aviation hybrid electric propulsion engine. Specifically, as Figure 1 As shown, the three-stream engine 100 includes an electric motor 200 operably coupled to the LP shaft 138. The electric motor 200 includes a rotor 202 and a stator 204. The electric motor 200 can be directly mechanically coupled to the LP shaft 138, or alternatively, the electric motor 200 can be indirectly mechanically coupled to the LP shaft 138, such as through a gearbox. Furthermore, although the electric motor 200 is operably coupled to the LP shaft 138 at the rear end of the LP shaft 138, the electric motor 200 can be coupled to the LP shaft 138 at any suitable location, or can be coupled to other rotating components of the three-stream engine 100, such as the HP shaft 136.

[0032] In some embodiments, motor 200 may be an electric motor operable to drive or propel LP shaft 138, such as during an engine burst. In other embodiments, motor 200 may be a generator operable to convert mechanical energy into electrical energy. Thus, the electrical power generated by motor 200 may be directed to various engine and / or aircraft systems. In some embodiments, motor 200 may be a dual-function motor / generator.

[0033] Now refer to Figure 2 , shows an exemplary stator 204 for an electric machine 200 (specifically, an electric motor). The stator 204 defines an axial direction A', a radial direction R', and a circumferential direction C'. In certain exemplary embodiments, Figure 2 The exemplary stator 204 may incorporate Figure 1 In such an exemplary embodiment, it will be appreciated that the axes for directions A', R', and C' are defined relative to the motor 200 and may or may not be aligned with the directions A, R, C of the three-stream engine 100.

[0034] The stator 204 includes a stator core 206 defining a plurality of slots 208 extending in an axial direction A' from a first end 210 of the stator core 206 to a second end 212 of the stator core 206. The stator 204 includes a plurality of wires 214 arranged as windings disposed in the slots 208 and a plurality of coolant tubes 216 disposed through the plurality of slots 208, the plurality of coolant tubes 216 extending in the axial direction A' from the first end 210 to the second end 212. Each of the plurality of coolant tubes 216 extends from a tube inlet 218 to a tube outlet 220 (at Figure 4 2). The stator core 206 includes a manifold 222 extending around the stator core 206 in a circumferential direction C′ and fluidly connected to each of the plurality of coolant tubes 216. The stator 204 includes a coolant supply 224 fluidly connected to the manifold 222 to supply coolant 226 to the manifold 222 and the coolant tubes 216. The stator 204 includes a thermally conductive potting material 228 disposed in the plurality of slots 208, between the plurality of coolant tubes 216, the plurality of wires 214, and the stator core 206.

[0035] The stator core 206 is the stationary portion of the electric motor 200, providing a structure to house the rotor 202 (not shown) that rotates within the stator 204. The stator core 206 and the plurality of wires 214 act as electromagnets during operation of the electric motor 200. That is, as the rotor 202 rotates within the stator 204, the rotor 202 induces current through the plurality of wires 214, thereby generating an electric current. In this configuration, the electric motor 200 acts as a generator, generating electricity for use by other components.

[0036] Alternatively, by providing current to the plurality of wires 214, the stator 204 generates a magnetic field that rotates the rotor 202, thereby providing rotational motion to the rotor shaft (not shown) to drive other components. In this configuration, the motor 200 acts as a motor that drives another component to rotate.

[0037] During operation of the electric machine, resistance in the plurality of wires 214 generates heat, which may interfere with the flow of electrical current. As will be explained in greater detail below, the plurality of coolant tubes 216 and the thermally conductive potting material 228 dissipate heat from the plurality of wires 214, thereby improving the performance of the electric machine 200.

[0038] like Figure 2As shown, the stator 204 includes a thermally conductive potting material 228. The potting material 228 is disposed between the first end 210 and the second end 212 of the stator core 206, extending into the plurality of slots 208 between the plurality of coolant tubes 216, the plurality of wires 214, and the stator core 206, covering the first end 210, the second end 212, and the manifold 222. The potting material 228 absorbs heat from the plurality of coolant tubes 216 and the plurality of wires 214, thereby increasing heat transfer from the stator 204. The potting material 228 may include an electrically insulating material, such as an epoxy, a silicone-based resin, or both. The potting material 228 is applied in liquid or gel form and then cured into a solid form during a heat treatment or drying process. The solid potting material 228 contacts the stator core 206 and the plurality of wires 214, securing the plurality of wires 214 within the plurality of slots 208. Thus, the potting material 228 secures the plurality of wires 214 to the stator core 206 , thereby improving the structural integrity and conductive heat transfer of the stator 204 .

[0039] The stator core 206 includes a plurality of wedges 230, each of which encloses a respective wire 214 and a respective coolant tube 216 within a respective slot 208. The wedges 230 are angular components shaped to be fixedly attached to the stator core 206, held in place by friction in the slot 208. The plurality of wedges 230 and the stator core 206 form an inner surface 232 of the stator 204 in the radial direction R'. The plurality of wedges 230 can be substantially flush with the stator core 206, such that the inner surface 232 is substantially smooth.

[0040] Now refer to Figure 3 , Figure 2 A close-up view of the stator 204 shows the plurality of wires 214 with the potting material 228 removed and shown in phantom to illustrate the arrangement of the coolant tubes 216 and wires 214 within the slots 208. As described above, the plurality of coolant tubes 216 provide coolant 226 to the plurality of wires 214, thereby transferring heat generated by the wires 214 away from the stator 204. Because the plurality of wires 214 extend from the first end 210 to the second end 212, heat is generated along the entire axial length of the slots 208. Therefore, the plurality of coolant tubes 216 extend through the plurality of slots 208 from the first end 210 to the second end 212 to dissipate heat from the entire length of the plurality of wires 214. To dissipate heat from the plurality of wires 214, at least one of the plurality of wires 214 transfers heat to the coolant tubes 216 via conduction, either directly or through an intermediate heat transfer medium. The coolant 226 flowing through the coolant tubes 216 is heated by contact with the coolant tubes 216 , and the heated coolant 226 flows out of the slots 208 , dissipating heat away from the stator 204 .

[0041] Now refer to Figure 4 , showing Figure 3 The stator 204 with the stator core 206 and the plurality of wires 214 removed to show the manifold 222 and the coolant tubes 216. Figure 4 In the exemplary embodiment, the tube inlet 218 of each coolant tube 216 is disposed at the first end 210, and the tube outlet 220 of each coolant tube 216 is disposed at the second end 212. The coolant tubes 216 are arranged parallel to each other to allow coolant 226 to flow through each of the coolant tubes 216 substantially simultaneously.

[0042] The manifold 222 extends in the circumferential direction C′ around the stator core 206 outside of the stator core 206 in the radial direction R′, fluidly connecting to each of the plurality of coolant tubes 216 . Figure 4 Manifold 222 includes a first portion 234 including a manifold inlet 236 and a second portion 238 including a manifold outlet 240. First portion 234 is disposed at first end 210 and is fluidly connected to a corresponding tube inlet 218 of each of the coolant tubes 216. Second portion 238 of manifold 222 is disposed at second end 212 and is fluidly connected to a corresponding tube outlet 220 of each of the coolant tubes 216. In this configuration, each of the coolant tubes 216 extends from first portion 234 of manifold 222 to second portion 238 of manifold 222. Coolant supply 224 is fluidly connected to manifold inlet 236 and manifold outlet 240. Coolant 226 flows from coolant supply 224 to manifold inlet 236, enters each tube inlet 218, passes through each coolant tube 216, exits through each tube outlet 220, reaches manifold outlet 240, and returns to coolant supply 224.

[0043] Now refer to Figure 5 , another exemplary embodiment of a stator 250 is shown. Figure 5 The stator 250 can be Figure 2 The exemplary stators are configured in substantially the same manner, and common structures share common numbers and common functions as described above. In this embodiment, a plurality of coolant tubes 252 extend along the wedges 230 of the stator core 206, beneath the plurality of wires 214, extending inward in the radial direction R'. The arrangement of the coolant tubes 252 along the wedges 230 provides additional space within the slots 208 for the wires 214. The thermally conductive potting material 228 absorbs heat from the manifold 222 and coolant tubes 252, further increasing heat transfer from the wires 214.

[0044] refer to Figure 6, provides a partial schematic diagram of a stator 250 without the thermally conductive potting material 228, with a coolant tube 252 extending along a wedge 230 to contact the wires 214, through which coolant 226 flows to cool the wires 214. In an embodiment, the wedge 230 forms a surface that the coolant tube 252 mates with or contacts. Through this mating configuration, the wedge 230 can additionally transfer heat away from the coolant tube 252, thereby increasing the overall heat transfer from the wires 214. In addition, the wedge 230 can support the coolant tube 252 in the slot 208, keeping the coolant tube 252 against the wires 214 to increase contact therebetween, thereby increasing conductive heat transfer.

[0045] Now refer to Figure 7 , providing a partial schematic diagram of a stator 250 without the wires 214, a coolant tube 252 flows coolant 226 in an axial direction A′ between a first portion 234 and a second portion 238 of the manifold 222 to cool the wires 214. The coolant 226 flows through the coolant tube 252 from the tube inlet 218 at the first end 210 to the tube outlet 220 at the second end 212, where the second portion 238 of the manifold 222 removes the coolant 226 to the coolant supply 224.

[0046] Now refer to Figure 8 , a flow chart of a method 300 of forming a stator for an electric machine according to an exemplary aspect of the present disclosure is provided. Figure 8 The method 300 can be used to construct the above reference Figure 1-Figure 7 Thus, it should be understood that method 300 can generally be used to manufacture electric machines for gas turbine engines as described above. However, in other exemplary aspects, method 300 can additionally or alternatively be used to manufacture any other electric machines.

[0047] As shown, the method 300 includes extending a plurality of wires along a plurality of coolant tubes through a plurality of slots at (302). The plurality of wires extend from a first end of a stator core to a second end of the stator core.

[0048] The method includes extending a plurality of coolant tubes through a plurality of slots of a stator core at (304). The coolant tubes extend in an axial direction from a first end of the stator core to a second end of the stator core. The coolant tubes may each have a tube inlet at a first end and a tube outlet at a second end. The coolant tubes may be disposed between adjacent windings of the plurality of wires, or the coolant tubes may be disposed below the plurality of wires.

[0049] The method includes placing a manifold in a circumferential direction around the stator core and connecting coolant tubes to the manifold at (306). The manifold provides coolant from a coolant supply to a corresponding tube inlet of each of the plurality of coolant tubes. A first portion of the manifold is placed at a first end, and a second portion of the manifold is placed at a second end.

[0050] The method includes applying a thermally conductive potting material to a first end and a second end of the stator core, a plurality of electrical wires, a plurality of coolant tubes, and a manifold at (308). The thermally conductive potting material is applied in liquid or gel form to cover surfaces of the stator core and the manifold.

[0051] The method includes curing the thermally conductive potting material into a solid state at (310). After curing into a solid state, the thermally conductive potting material secures the plurality of electrical wires and the plurality of coolant tubes in the plurality of slots. The solid thermally conductive potting material transfers heat away from the coolant tubes and the plurality of electrical wires, thereby improving cooling of the stator.

[0052] The method includes flowing a coolant through a manifold and coolant tubes at (312). The manifold is connected to a coolant supply that provides coolant to the coolant tubes. The coolant flows from a tube inlet of each of the coolant tubes to a tube outlet of each of the plurality of coolant tubes, thereby transferring heat away from the plurality of wires.

[0053] Further aspects are provided by the subject matter of the following clauses:

[0054] A stator for an electric motor, the stator defining an axial direction, a circumferential direction, and a radial direction, the stator comprising: a stator core defining slots extending from a first end to a second end in the axial direction; wires disposed in the slots; a coolant tube disposed in the slots and extending from the first end to the second end in the axial direction, the coolant tube extending from a tube inlet to a tube outlet; and a thermally conductive potting material disposed in the slots and between the coolant tube, the wires, and the stator core.

[0055] A stator as claimed in any preceding clause, wherein the wires are supported in the slots by the thermally conductive potting material.

[0056] The stator according to any of the preceding clauses, wherein the tube inlet of the coolant tube is provided at the first end of the stator core, and wherein the tube outlet of the coolant tube is provided at the second end of the stator core.

[0057] A stator as claimed in any preceding clause, wherein the thermally conductive potting material secures the wires to the stator core.

[0058] A stator as claimed in any one of the preceding clauses, wherein the thermally conductive potting material is an epoxy resin, a silicone-based resin, or both.

[0059] A stator as claimed in any preceding clause, wherein the coolant tube contacts the electrical wires.

[0060] The stator of any of the preceding clauses, further comprising a coolant disposed in the coolant tube, the coolant being configured to dissipate heat from the wires when flowing through the coolant tube.

[0061] A stator according to any of the preceding clauses, further comprising a manifold extending around the stator core in the circumferential direction, the manifold being fluidly connected to the coolant tubes.

[0062] A stator according to any of the preceding clauses, wherein the manifold is connected to the tube inlets of the coolant tubes and to the tube outlets of the coolant tubes.

[0063] A stator as claimed in any preceding clause, wherein the thermally conductive potting material is provided on the manifold.

[0064] The stator of any of the preceding clauses, further comprising a plurality of coolant tubes including the coolant tube, wherein at least some of the plurality of coolant tubes are arranged parallel to each other.

[0065] A stator as claimed in any preceding clause, further comprising a coolant supply fluidly connected to the coolant tube.

[0066] A stator as claimed in any preceding clause, wherein the stator core defines a plurality of slots.

[0067] A stator according to any of the preceding clauses, further comprising a plurality of wires.

[0068] A method of forming a stator for an electric machine, the stator defining an axial direction and a circumferential direction, the method comprising: extending a plurality of wires in each of a plurality of slots in a stator core; extending at least one of a plurality of coolant tubes in each of the plurality of slots in the axial direction; and applying a thermally conductive potting material to an end portion of the stator core over the plurality of wires and the plurality of coolant tubes.

[0069] The method of any of the preceding clauses, wherein the thermally conductive potting material is an epoxy resin, a silicone-based resin, or both.

[0070] The method of any of the preceding clauses, further comprising curing the thermally conductive potting material to secure the plurality of wires to the stator core.

[0071] The method of any of the preceding clauses, further comprising flowing a coolant through the plurality of coolant tubes to dissipate heat from the plurality of wires.

[0072] The method of any of the preceding clauses, further comprising extending at least one of the plurality of coolant tubes along a wedge of the stator core.

[0073] The method of any of the preceding clauses, further comprising placing a manifold around the stator core in the circumferential direction, the manifold being in fluid communication with the plurality of coolant tubes, and then applying the thermally conductive potting material to the ends of the stator core and the manifold.

[0074] The method of any of the preceding clauses, wherein each of the plurality of coolant tubes extends from a tube inlet connected to the manifold to a tube outlet connected to the manifold.

[0075] An aircraft gas turbine engine comprises: a turbine, the turbine comprising a compressor, a combustor and a turbine arranged in a series flow sequence; and an electric motor, the electric motor defining an axial direction, the electric motor comprising a stator and a rotor, the rotor being rotatable with the turbine, the stator comprising: a stator core, the stator core defining a plurality of slots extending from a first end to a second end in the axial direction; a plurality of wires disposed in the plurality of slots; a plurality of coolant tubes disposed so as to pass through the plurality of slots and extend from the first end to the second end in the axial direction, each of the plurality of coolant tubes extending from a tube inlet to a tube outlet; and a thermally conductive potting material disposed in the plurality of slots, between the plurality of coolant tubes, the plurality of wires and the stator core.

[0076] An aircraft gas turbine engine according to any one of the preceding clauses, wherein the plurality of wires are supported in the slot by the thermally conductive potting material.

[0077] The aircraft gas turbine engine according to any of the preceding clauses, wherein the tube inlet of at least one of the plurality of coolant tubes is arranged at the first end of the stator core, and wherein the tube outlet of at least one of the plurality of coolant tubes is arranged at the second end of the stator core.

[0078] An aircraft gas turbine engine according to any one of the preceding clauses, wherein the thermally conductive potting material secures the plurality of wires to the stator core.

[0079] An aircraft gas turbine engine according to any one of the preceding clauses, wherein the thermally conductive potting material is an epoxy resin, a silicone-based resin, or both.

[0080] The aircraft gas turbine engine according to any of the preceding clauses, wherein at least one of the plurality of coolant tubes contacts at least one of the plurality of electrical wires.

[0081] The aircraft gas turbine engine according to any of the preceding clauses, further comprising a coolant disposed in the plurality of coolant tubes, the coolant being configured to dissipate heat from the plurality of wires when flowing through the plurality of coolant tubes.

[0082] The aircraft gas turbine engine according to any of the preceding clauses, further comprising a manifold extending around the stator core in the circumferential direction, the manifold being fluidly connected to the plurality of coolant tubes.

[0083] The aircraft gas turbine engine according to any of the preceding clauses, wherein the manifold is connected to the tube inlet of at least one of the plurality of coolant tubes and to the tube outlet of at least one of the plurality of coolant tubes.

[0084] An aircraft gas turbine engine according to any one of the preceding clauses, wherein the thermally conductive potting material is provided on the manifold.

[0085] An aircraft gas turbine engine according to any of the preceding clauses, wherein at least some of the plurality of coolant tubes are arranged parallel to each other.

[0086] An aircraft gas turbine engine according to any of the preceding clauses, further comprising a coolant supply fluidly connected to at least one of the plurality of coolant tubes.

[0087] This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure 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 with insubstantial differences from the literal language of the claims.

Claims

1. A stator for an electric motor, the stator defining an axial direction, a circumferential direction and a radial direction, characterized in that: The stator comprises: a stator core defining slots extending in the axial direction from a first end to a second end; an electric wire disposed in the groove; a coolant tube disposed in the groove and extending in the axial direction from the first end to the second end, the coolant tube extending from a tube inlet to a tube outlet; and A thermally conductive potting material is disposed in the slots between the coolant tubes, the wires, and the stator core.

2. The stator according to claim 1, characterized in that in, The wires are supported in the grooves by the thermally conductive potting material.

3. The stator according to claim 1, characterized in that in, The tube inlet of the coolant tube is provided at the first end of the stator core, and wherein the tube outlet of the coolant tube is provided at the second end of the stator core.

4. The stator according to claim 1, characterized in that in, The thermally conductive potting material secures the wires to the stator core.

5. The stator according to claim 1, characterized in that in, The thermally conductive potting material is epoxy resin, silicone-based resin or both.

6. The stator according to claim 1, characterized in that in, The coolant pipe contacts the electric wire.

7. The stator according to claim 1, characterized in that Further included is a coolant disposed in the coolant tube, the coolant being configured to dissipate heat from the wire when flowing through the coolant tube.

8. The stator according to claim 1, characterized in that Further included is a manifold extending around the stator core in the circumferential direction, the manifold being fluidly connected to the coolant tubes.

9. The stator according to claim 8, characterized in that in, The manifold is connected to the tube inlets of the coolant tubes and to the tube outlets of the coolant tubes.

10. The stator according to claim 8, characterized in that in, The thermally conductive potting material is disposed on the manifold.

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