Electric motor

Abstract

An electric machine may include a stator core having a plurality of core teeth that define a plurality of core slots in a surface of the stator core. A winding may be at least partially received in the core slots. The winding may include a tube and one or more wire strands, the tube defining a passageway through at least a portion thereof, and the one or more wire strands being disposed along a surface of the tube opposite the passageway. A cooling system may be operably coupled to the passageway and configured to move a cooling fluid through the passageway.

Description

Technical Field

[0001] The present subject matter generally relates to an electric machine having a cooling system fluidly coupled to one or more windings of the electric machine. Background Art

[0002] Electric machines, such as generators, motors, motor / generators, starter / generators, and other electric machines can be used for various purposes. In operation, an electric machine includes a rotor that is rotatable relative to a stator to generate electrical energy and / or that can rotate relative to the stator due to a changing magnetic field induced in windings of the stator. Losses and heat are generated during operation of the electric machine, which can have a negative impact on the efficiency or performance of the electric machine. Thus, an electric machine that can dissipate additional heat would be useful. Summary of the Invention

[0003] Technical Solution 1. An electric machine, comprising:

[0004] A stator core that defines a plurality of core slots in its surface;

[0005] A winding that is at least partially positioned in one of the plurality of core slots, the winding including a tube and one or more wire strands, the tube defining a passage through at least a portion thereof, the wire strands being disposed along the tube opposite the passage; and

[0006] A cooling system that is operably coupled to the passage and is configured to move a cooling fluid through the passage.

[0007] Technical Solution 2. The electric machine according to any of the technical solutions, further comprising:

[0008] A controller that is operably coupled to the cooling system and is configured to operate a pump of the cooling system.

[0009] Technical Solution 3. The electric machine according to any of the technical solutions, wherein the one or more wire strands are configured as stranded wire strands having a plurality of strands.

[0010] Technical Solution 4. The electric machine according to any of the technical solutions, wherein each of the plurality of strands is separately coated with an insulating layer.

[0011] Technical Solution 5. The electric machine according to any of the technical solutions, wherein the one or more wire strands include a plurality of wire strands positioned around an outer surface of the tube, and wherein each of the plurality of wire strands includes an outer sheath.

[0012] Technical Solution 6. The electric machine according to any of the technical solutions, further comprising:

[0013] A strip disposed around each of the plurality of wire rods, wherein the strip extends in a direction substantially perpendicular to each of the plurality of wire rods.

[0014] Technical solution 7. The electric machine according to any one of the technical solutions, wherein the channel includes a first channel and a second channel separated from the first channel.

[0015] Technical solution 8. The electric machine according to any one of the technical solutions, wherein the one or more wire rods include a first group of wire rods positioned between the first channel and the second channel and a second group of wire rods positioned around the first channel, the second channel, and the first group of wire rods.

[0016] Technical solution 9. The electric machine according to any one of the technical solutions, wherein the first group of wire rods belongs to a first specification, and the second group of wire rods belongs to a second specification, and the first specification is different from the second specification.

[0017] Technical solution 10. The electric machine according to any one of the technical solutions, further comprising:

[0018] One or more inner surface features within the channel.

[0019] Technical solution 11. The electric machine according to any one of the technical solutions, wherein the tube is formed of a first material, and the one or more wire rods include a second material, and wherein the first material is the same as the second material.

[0020] Technical solution 12. The electric machine according to any one of the technical solutions, wherein the tube is formed of a first material, and the one or more wire rods include a second material, and wherein the first material is different from the second material.

[0021] Technical solution 13. A method of manufacturing an electric machine, the method comprising:

[0022] Positioning one or more wire rods around the surface of a tube to form a winding, wherein the tube defines a channel through at least a portion thereof, and wherein the one or more wire rods are separated from the channel by the tube;

[0023] Operably coupling the winding to one of a stator core or a rotor of the electric machine; and

[0024] Fluidly coupling a cooling system to the channel.

[0025] Technical solution 14. The method according to any one of the technical solutions, wherein each of the one or more wire rods is configured as a stranded wire having a plurality of strands.

[0026] Aspect 15. The method according to any of the aspects, wherein fluidly coupling the cooling system to the channel includes coupling a supply line to one end portion of the winding and coupling a return line to a second end portion of the winding.

[0027] Aspect 16. The method according to any of the aspects, wherein fluidly coupling the cooling system to the channel further includes fluidly coupling a pump and a heat exchanger in series between the supply line and the return line.

[0028] Aspect 17. A winding assembly for an electric machine, comprising:

[0029] a tube defining a channel through at least a portion thereof, the tube being configured to be operatively coupled to a stator or a rotor of the electric machine; and

[0030] one or more wires positioned along the tube opposite the channel.

[0031] Aspect 18. The electric machine according to any of the aspects, wherein the one or more wires are configured as stranded wires, and a cooling system is operatively coupled to the channel and is configured to move a cooling fluid through the channel.

[0032] Aspect 19. The electric machine according to any of the aspects, wherein the one or more wires include a first set of wires and a second set of wires, and wherein the tube includes a first tube and a second tube.

[0033] Aspect 20. The electric machine according to any of the aspects, wherein the second set of wires is positioned between the first tube and the second tube, and the first set of wires is positioned around the first tube, the second tube, and the second set of wires.

[0034] Aspects and advantages of the present invention will be set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the present invention.

[0035] In some embodiments of the present disclosure, the electric machine includes a stator core defining a plurality of core slots in its surface. A winding is at least partially positioned in one of the plurality of core slots. The winding includes a tube and one or more wires, the tube defining a channel through at least a portion thereof, and the one or more wires are arranged along the tube opposite the channel. A cooling system is operatively coupled to the channel and is configured to move a cooling fluid through the channel.

[0036] In some embodiments of the present disclosure, a method of manufacturing an electric machine includes positioning one or more wire strands around a surface of a tube to form a winding. The tube defines a passageway through at least a portion thereof, and the one or more wire strands are separated from the passageway by the tube. The method further includes operatively coupling the winding to one of a stator core or a rotor of the electric machine. The method further includes fluidly coupling a cooling system to the passageway.

[0037] In some embodiments of the present disclosure, a winding assembly for an electric machine includes a tube that defines a passageway through at least a portion thereof. The tube is configured to be operatively coupled to a stator or a rotor of the electric machine. One or more wire strands are positioned along the tube opposite the passageway.

[0038] 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 embodiments of the invention and, together with the description, serve to explain the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] A complete 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 makes reference to the appended drawings, in which:

[0040] Figure 1 is a perspective view of an electric machine having a rotor positioned within a stator core, in accordance with various aspects of the present disclosure;

[0041] Figure 2 is taken along line II-II of Figure 1 a cross-sectional view of the electric machine;

[0042] Figure 3 is a schematic view of a cooling system operatively coupled to one or more windings of an electric machine, in accordance with various aspects of the present disclosure;

[0043] Figure 4 is a perspective view of a portion of one of the windings defining a passageway, in accordance with various aspects of the present disclosure;

[0044] Figure 5 is a perspective view of an end portion of one of the windings defining a passageway, in accordance with various aspects of the present disclosure;

[0045] Figure 6 is along Figure 5 a cross-sectional view of one of the windings taken along line VI-VI of

[0046] Figure 7 is along Figure 5 a schematic cross-sectional view of one of the windings taken along line VI-VI of

[0047] Figure 8 is a schematic cross-sectional view of one of the windings taken along line VI-VI Figure 5 in accordance with various aspects of the present disclosure;

[0048] Figure 9 is a perspective view of an end portion of one of the windings that defines a channel in accordance with various aspects of the present disclosure;

[0049] Figure 10 is a cross-sectional view of one of the windings taken along line X-X Figure 9 in accordance with various aspects of the present disclosure;

[0050] Figure 11 is a schematic cross-sectional view of one of the windings taken along line X-X Figure 9 in accordance with various aspects of the present disclosure;

[0051] Figure 12 is a schematic cross-sectional view of one of the windings taken along line X-X Figure 9 in accordance with various aspects of the present disclosure; and

[0052] Figure 13 is a flow chart of a method for operating an electric machine in accordance with various aspects of the present disclosure. DETAILED DESCRIPTION

[0053] Reference will now be made in detail to the present embodiments of the invention, 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. The same or similar designations in the drawings and description are used to refer to the same or similar parts of the invention.

[0054] As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to denote the position or importance of the individual components.

[0055] The terms "front" and "rear" refer to relative positions within a gas turbine engine or a vehicle and refer to the normal operating attitude of the gas turbine engine or the vehicle. For example, with respect to a gas turbine engine, the front refers to a position closer to the engine inlet, while the rear refers to a position closer to the engine nozzle or exhaust.

[0056] The terms "upstream" and "downstream" refer to the relative direction with respect to the flow path of the cooling fluid in a fluid path. For example, "upstream" refers to the direction from which the cooling fluid flows, and "downstream" refers to the direction to which the cooling fluid flows.

[0057] Unless otherwise specified herein, the terms "coupled", "fixed", "attached", etc. refer to direct coupling, fixing, or attachment, as well as indirect coupling, fixing, or attachment through one or more intermediate components or features.

[0058] The singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise.

[0059] As used throughout the specification and claims, approximate language is used to modify any quantitative representation, and that quantitative representation can vary without resulting in a change in the basic function associated therewith. Thus, values modified by terms such as "about", "approximately", "generally", and "substantially" are not limited to the precise values specified. In at least some instances, the approximate language can correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the components and / or systems. For example, the approximate language can refer to within a ten percent margin.

[0060] Herein, as well as throughout the specification and claims, range limitations are combined and interchanged, and such ranges are identified and include all subranges subsumed therein unless the context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of one another.

[0061] As used herein, the term "and / or" when used in a list of two or more items means that any one of the listed items can be used alone, or any combination of two or more of the listed items can be used. For example, if a composition or assembly is described as including components A, B, and / or C, the composition or assembly can include A alone; B alone; C alone; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C.

[0062] Generally speaking, the present disclosure provides a conductive winding that can be operably coupled to the stator and / or rotor of an electric machine or any other device incorporating conductive material. During operation, the rotor can be mechanically powered, driven, or rotated about a rotational axis by a force (such as the mechanical energy of an engine). Due to the interaction of the magnetic fields of the electric machine, the relative rotational movement of the rotatable rotor with respect to the fixed or stationary stator generates electrical power in one or more windings. The electrical power generated in one or more windings can be conductively connected to at least one electrical load or power source and further delivered to at least one electrical load or power source. In some aspects, the electric machine can provide electrical power to a power distribution system or network. In contrast, when operating as an electric motor, alternating electrical power (such as three-phase alternating electrical power) can be provided to one or more windings of the stator, which results in the rotational movement of the rotor.

[0063] The conductive winding can include a tube and one or more wires. The tube defines a channel therein, and the one or more wires can be positioned along a side of the tube opposite the channel. Each of the tube and the one or more wires can be formed of a conductive material. In various examples, the one or more wires can be configured as stranded wires (or Litz wires), and the stranded wires have a plurality of intertwined strands that can be insulated from each other.

[0064] The cooling system can be operably coupled to the channel and configured to move a cooling fluid through the channel. When the cooling fluid moves through the channel, heat is received from the winding into the cooling fluid, and then the cooling fluid is at least partially removed from the cooling fluid outside the winding. The heated cooling fluid can be cooled by a heat exchanger that can be located outside the winding.

[0065] The electric machine provided herein can improve the thermal performance of an electric machine employing a cooling system. By implementing one or more stranded wires along the tube, the electric machine can operate with higher efficiency, generate more power, and / or reduce its package size while operating at the same power as currently available electric machines.

[0066] Reference is now made to the accompanying drawings, in which like numbers represent like elements throughout the drawings, Figure 1 and 2 There is provided an electric machine 10 that includes a stator 12 operably coupled to a rotor 14. During operation, the rotor 14 can be mechanically powered, driven, or rotated about a rotational axis by a force (such as the mechanical energy of an engine). Due to the interaction of the magnetic fields of the electric machine, the rotational movement of the rotatable rotor 14 relative to the fixed or stationary stator 12 generates electrical energy in one or more windings 16. The electrical energy generated in the one or more windings 16 can be conductively connected to at least one electrical load or power source and further delivered to the at least one electrical load or power source. In some aspects, the electric machine 10 can provide electrical power to a power distribution system or network. In contrast, when operating as an electric motor, alternating current power (such as three-phase alternating current power) can be provided to one or more windings 16 of the stator 12, which generates a rotational movement of the rotor 14. In various embodiments, the electric machine 10 provided herein can be an alternating current (AC) synchronous machine, an AC induction machine, a switched reluctance machine, or any other viable type of electric machine.

[0067] As Figure 1 and 2As provided, the stator 12 may include a stator core 18 and windings 16 operably coupled to the stator core 18. The stator core 18 may have a generally cylindrical shape that may define a plurality of core slots 20 formed in the inner circumferential diameter 22 of the stator core 18. The core slots 20 may extend between a first end portion 24 and a second end portion 26 of the stator core 18. In various embodiments, the core slots 20 are spaced equidistantly around the inner circumferential diameter 22 of the stator core 18, spaced non-equidistantly around the inner circumferential diameter 22 of the stator core 18, and / or a combination of both. The core slots 20 define a radial depth between the end portions 24, 26 of the core slots 20.

[0068] The core slots 20 are adapted to receive one or more windings 16. The core slots 20 may have a rectangular cross-sectional shape as Figure 1 visible and / or any other shape without departing from the teachings provided herein. In some embodiments, each winding 16 may have a plurality of segments that may include one or more slot segments 28 received in the core slots 20 and one or more end turn segments 30.

[0069] Still referring to Figure 1 and 2 , the rotor 14 may include a rotor core 32 and one or more windings 16 and / or magnets 34 supported by the rotor core 32. The rotor 14 may also support a rotatable shaft 36 and / or be operably coupled to the rotatable shaft 36. In various embodiments, the rotor 14 may be, but is not limited to, a "claw pole" rotor, a permanent magnet non-claw pole rotor, a permanent magnet claw pole rotor, a salient pole field wound rotor, or an induction type rotor.

[0070] Figure 3 A schematic diagram of a motor 10 and a cooling system 40 according to an embodiment of the present disclosure is provided. Figure 4 Provided is Figure 3 an independent perspective view of the windings of the motor 10 in Figure 1 . To maintain the temperature of the motor 10 (

[0071] In some embodiments, the cooling system 40 can supply a cooling fluid 44 to windings 16 of the stator 12 and / or the rotor 14, where the cooling fluid 44 is in the form of lubricating oil, a consumable liquid (such as water), a gas, a supercritical vapor, and / or any other suitable cooling fluid. In various embodiments, the cooling fluid 44 can have a high specific heat capacity to transfer heat from the windings 16 via the cooling fluid flow path FP to the cooling system 40, a low dynamic viscosity to reduce the amount of power required to move the cooling fluid 44 through the cooling system 40 and the channels 42, a high flash / boiling temperature to allow for high operating temperatures, a high dielectric strength to withstand the potential difference across the windings 16 (otherwise, corona would occur, which would start pitting and corroding the insulation of the windings 16), be electrically insulating to avoid axial circulating currents that increase losses due to the potential difference across the windings 16 axially through the cooling fluid 44, and / or have high corrosion resistance to avoid corrosion of the motor 10 over time where the cooling fluid 44 comes into contact. For the example shown, the cooling system 40 can include a cooling system supply line 46 and a return line 48 that communicate with one or more of the windings 16. The cooling system supply line 46 and the return line 48 transport the cooling fluid 44 to and from the channels 42. It will be understood that the cooling system supply line 46 and the return line 48 can be formed in a variety of configurations suitable for this purpose. Additionally, in some embodiments, for example, an isolation breaker 50 can be provided along each of the supply line 46 and the return line 48, for example to prevent current from flowing from the windings 16 to the cooling system 40 in embodiments where the cooling system 40 can include conductive materials (such as metal).

[0072] The pump assembly 52 (and / or compressor assembly) is positioned relative to one or more of the windings 16 between the cooling system supply line 46 and the return line 48. The pump assembly 52 can move the cooling fluid 44 through the channels 42. In some embodiments, the pump assembly 52 can be configured to maintain the flow rate of the cooling fluid 44 below a maximum desired flow rate, which can reduce and / or prevent corrosion of the channels 42.

[0073] In some cases, the cooling system 40 can include a heat exchanger 56 that communicates with both the cooling system supply line 46 and the return line 48. In some cases, the heat exchanger 56 can be located between the windings 16 and the pump assembly 52, or at any other location within the cooling assembly. In some examples, the heat exchanger 56 can be configured to transfer thermal energy from the cooling fluid 44 to the atmosphere, which can reduce the temperature of the cooling fluid 44. Although the heat exchanger 56 has been referenced herein, it should be understood that the present disclosure contemplates the use of any existing or future method for transferring thermal energy that will operate as described and claimed.

[0074] In some examples, the flow of the cooling fluid 44 can be considered to be a closed loop. However, losses of the cooling fluid 44 are considered during normal operation. To this end, the cooling system 40 can further include a reservoir 58 in communication with the return line 48 to replace any losses of the cooling fluid 44.

[0075] Further referring Figure 3 and Figure 4 , the cooling system 40, the stator 12, and / or the motor 10 can further include a computing system 60 (or be operably coupled thereto) that causes the motor 10 to perform certain functions, such as the operation of the pump assembly 52. One or more functions can be any of the components of the cooling system 40 and / or the motor 10. The computing system 60 can include one or more computing devices 62. The (one or more) computing devices 62 can include one or more processors 64 and one or more memory devices 66. The one or more processors 64 can include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing device. The one or more memory devices 66 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0076] The one or more memory devices 66 can store information accessible by the one or more processors 64, including computer-readable instructions 68 executable by the one or more processors 64. The instructions 68 can be any set of instructions that, when executed by the one or more processors 64, cause the one or more processors 64 to perform operations. In some embodiments, the instructions 68 can be executed by the one or more processors 64 to cause the one or more processors 64 to perform operations, such as any operations and functions for which the (one or more) computing system 60 and / or the computing device 62 are configured, operations for operating the cooling system 40 and / or the motor 10, and / or any other operations or functions of the one or more computing devices 62. The instructions 68 can be software written in any suitable programming language or can be implemented in hardware. Additionally and / or alternatively, the instructions 68 can be executed on the (one or more) processors 64 in logically and / or virtually separated threads. The (one or more) memory devices 66 can further store data 70 that can be accessed by the (one or more) processors 64. For example, the data 70 can include data indicating motor temperature, winding temperature, cooling fluid temperature, cooling fluid flow rate, efficiency gains based on the use of the cooling system 40, and / or any other information. In some embodiments, these parameters can be used to adjust the cooling system 40, such as adjusting the coolant flow rate, in order to optimize operation, for aspects such as improving the efficiency of the cooling system and increasing the uniformity of the winding temperature.

[0077] (One or more) computing devices 62 may also include a network interface 72, which is used to communicate with, for example, other components of the cooling system 40 or any remote electronic device (e.g., via a network). The network interface 72 may include any suitable components for interfacing with one or more networks, including, for example, a transmitter, a receiver, ports, a controller, an antenna, and / or other suitable components. One or more external display devices (not depicted) may be configured to receive one or more commands, data, and / or information from (one or more) computing devices 62.

[0078] Now referring Figures 5 - 7 to, various views of the winding 16 of the present disclosure are provided. Figure 5 A perspective view of an end portion of one of the windings defining a channel according to some embodiments is provided. Figure 6 A cross-sectional view of one of the windings taken along line VI-VI of Figure 5 is provided. Figure 7 A schematic cross-sectional view of one of the windings taken along line VI-VI of Figure 5 is provided. In the illustrated embodiment, the winding 16 includes a tube 74 defining a channel 42 and one or more elongate wire elements 76 disposed on a side of the tube 74 opposite the channel 42. In some cases, one or more elongate wire elements 76 may form the tube 74 and / or the assembly may not have a tube 74. It may be noted that while the winding 16, the tube 74, and the channel 42 of Figure 6 and 7 are shown in the example illustration as having a generally rectangular shape, other shapes may be employed in alternative embodiments. It may also be noted that each of the tube 74 and the one or more wire elements 76 may be formed of a conductive or insulating material. In various embodiments, the tube 74 may be formed by an additive manufacturing process. For example, electron beam melting (EBM) may be used to form the winding 16 from a material having high electrical conductivity. However, it will be understood that in other embodiments, the winding 16 may be formed by any other suitable additive manufacturing process and / or any other suitable manufacturing process.

[0079] In some examples, each of the plurality of wire elements 76 may be a stranded wire having a plurality of conductive strands 78, the conductive strands 78 may be individually coated with an insulating layer 80, and then braided or plaited. During operation of the electric machine 10, current may tend to distribute itself within the conductor such that the current density near the surface of the conductor is greater than the current density closer to the center. This phenomenon is generally referred to as the "skin effect". In some high-frequency applications, the skin effect becomes more pronounced, resulting in power losses. Since stranded wire increases the resistance of the conductor to induced circulating current, the skin effect can be reduced by using stranded wire, thereby reducing the overall skin effect in the resulting wire.

[0080] Further reference is made to Figures 5 - 7 , each of the wire lines 76 may include an outer sheath 82 that surrounds and houses a plurality of conductor strands 78. The sheath 82 may insulate each wire line from an adjacent positioned wire line 76. In some embodiments, each of the elongated structures may extend around a portion of the tube 74 in a direction parallel or non-parallel to the tube 74.

[0081] In some cases, one or more strips 84 may be positioned around the tube 74, and one or more wire lines 76 may be positioned along the tube 74, which may allow the wire lines 76 to be in close contact with the tube 74. In some cases, the strip 84 may extend in a generally perpendicular direction relative to one or more of the wire lines 76. In various embodiments, the strip 84 may be electrically insulating, generally thermally insulating, and / or a combination of both.

[0082] In various embodiments, one or more wire lines 76 may be positioned around the tube 74, as Figure 6 shown, and / or one or more wire strands 78 may be distributed around the tube 74, as Figure 7 shown. Additionally, for Figure 6 the embodiments, one or more wire lines 76 include a plurality of wire lines 76, where the plurality of wire lines substantially completely surround and enclose the tube 74 (e.g., at least 90% surrounded, such as at least 95% surrounded, such as 100% surrounded). Additionally, for the embodiments shown, the plurality of wire lines 76 include at least 4 wire lines, such as at least 8 wire lines, such as at least 10 wire lines, such as at least 12 wire lines, such as up to 1,000 wire lines (counting each of the strands 78 in a stranded wire configuration as included in a single stranded wire).

[0083] In various embodiments, the tube 74 may be formed of a first material capable of conducting heat. In some cases, the tube 74 may also be conductive. Similarly, the wire lines 76 and / or the strands 78 may be formed of a second material that is also conductive. In various embodiments, the first material may be the same as the second material. More specifically, in certain embodiments, the first material may be the same by incorporating at least one element common to each of the first material and the second material and / or the first material and the second material may be the same compound.

[0084] However, it will be understood that in other embodiments, the first material may be different from the second material. In this way, the first material may define a higher thermal conductivity than the second material, and / or the second material may define a higher electrical conductivity than the first material.

[0085] In one or more of these embodiments, the first material and / or the second material can be a material that at least partially comprises copper (e.g., at least 99% pure copper). In other examples, the first material and / or the second material can be formed of any other electrically and / or thermally conductive material, such as copper alloy, silver, aluminum, aluminum alloy, and / or carbon nanotubes (CNT).

[0086] It will also be understood that in other embodiments, the winding 16 can have any other suitable configuration. For example, now referring to Figure 8 , there is provided a winding according to another embodiment of the present disclosure. In the embodiment of Figure 8 , the winding 16 is configured in substantially the same manner as the winding 16 of Figure 5 and 6 . However, the winding 16 of Figure 8 additionally includes more than one tube 74, and multiple sets of wire 76. In particular, for the embodiment of Figure 8 , the winding 16 includes two tubes 74, a first set 86 of wire 76, and a second set 88 of wire 76. Each tube 74 can be made of a first material (or each tube 74 can be made of a different material), the first set 86 of wire 76 can be made of a second material, and the second set 88 of wire 76 can be made of a third material. In some cases, each of the first material, the second material, and the third material can be substantially the same, and / or any of the first material, the second material, and the third material can be compositionally different from any of the remaining first material, second material, and third material. As provided above, the first material, the second material, and / or the third material can be a material that at least partially comprises copper (e.g., at least 99% pure copper), copper alloy, silver, aluminum, aluminum alloy, and / or carbon nanotubes (CNT), or any other viable material.

[0087] For the embodiment of Figure 8 , one or more tubes 74 include a first tube 74 and a second tube 74, and the first tube 74 and the second tube 74 are separated from each other by the second set 88 of wire 76 (e.g., the second set 88 of wire 76 is at least partially located between the first and second tubes 74). Additionally for this embodiment, the first set 86 of wire 76 is positioned around the first tube 74, the second tube 74, and the second set 88 of wire 76 in combination. In this way, for the depicted embodiment, the first set 86 of wire 76 encloses the first tube 74, the second tube 74, and the second set 88 of wire 76.

[0088] In some embodiments, both the first set 86 and the second set 88 of the wire strands 76 can be configured as stranded wire. However, in other embodiments, one of the first set 86 or the second set 88 of the wire strands 76 can be stranded wire while the other can be any other type of conductor. Additionally, in some embodiments, both the first set 86 and the second set 88 of the wire strands 76 can be configured as any other type of conductor other than stranded wire. In some cases, the first set 86 of the wire strands 76 belongs to a first specification and the second set 88 of the wire strands 76 belongs to a second specification. In various embodiments, the first specification can be different from the second specification. This can, for example, allow for efficient conveyance of various currents and voltages.

[0089] However, alternatively, in other embodiments, the first specification and the second specification can be the same. This can, for example, allow the winding 16 to most efficiently convey the desired current and / or voltage.

[0090] In some embodiments, such as Figure 7 the example shown in Figure 8 the winding 16 can have a first height h1 and a first width w1. Similarly, in Figure 8 the embodiment shown in

[0091] the winding 16 can have a second height h2 and a second width w2. In some cases, the second height can be less than the first height while the first width and the second width can be substantially equal. Thus, as Figures 9 - 12 shown in Figure 9 by including the first set 86 and the second set 88 of the wire strands 76 or any wire strands 76 between the tubes 74, the overall package size of the winding 16 can be reduced and / or the heat dissipation of the motor 10 can be increased. Figure 10 shown in Figure 9 the winding 16 can have a second height h2 and a second width w2. In some cases, the second height can be less than the first height while the first width and the second width can be substantially equal. Thus, as Figure 11 shown in Figure 9 the winding 16 can have a second height h2 and a second width w2. In some cases, the second height can be less than the first height while the first width and the second width can be substantially equal. Thus, as Figure 12 shown in Figure 9 the winding 16 can have a second height h2 and a second width w2. In some cases, the second height can be less than the first height while the first width and the second width can be substantially equal. Thus, as

[0092] In these embodiments, one or more inner surface features 90 (e.g., turbulators) positioned within the channel 42 can affect the flow of fluid 44 through the channel 42 by changing the pressure, changing the flow rate, changing the flow from laminar to turbulent (or vice versa), increasing the surface area of the channel 42 along the winding 16, thereby increasing the heat rejection properties of the winding 16, and so on. Generally speaking, all other things being equal, the more turbulent the flow, the greater the heat transfer rate. In other words, the higher the Reynolds number, the faster the heat transfer rate. Additionally, based on the local heat generation of the various parts of the winding 16, the inner surface features 90 can have different concentrations along the channel 42 of the winding 16, which can enhance the heat rejection from the winding 16 through the cooling system 40 and / or maintain a more uniform temperature along the winding 16.

[0093] In various embodiments, the inner surface feature 90 can be in the form of pins extending within at least a portion of the channel 42 of the winding 16 to promote mixing of the fluid 44 flow as the fluid 44 travels through the channel 42. However, in other embodiments, the inner feature 90 can include, but is not limited to, fins (rectangular, pin fins, etc.), columns, dimples, etc., which extend into the channel 42 to interact with the fluid 44. In other embodiments including circular cross-section channels 42, the inner features can be grooved fins / channels of various cross-sections, which improve heat transfer by inducing secondary flow. In any form, the inner surface feature 90 can increase the Reynolds number, indicating an increase in the turbulence of the fluid 44 passing through the channel 42. The position, size, and frequency of the inner surface feature 90 can be selected to minimize the increase in the power loss coefficient, as their presence creates higher pressure in order to move the cooling fluid 44 through the channel 42.

[0094] Now referring Figure 13 , a flowchart of a method 200 for manufacturing an electric machine according to various aspects of the present disclosure is provided. The electric machine produced by the disclosed method can be configured according to one or more of the embodiments described above and Figures 1 to 12 depicted in. As such, in at least some aspects, the electric machine 10 operated by the method 200 can be incorporated into an engine, such as an aircraft gas turbine engine, and can include a stator and a rotor.

[0095] As shown, the method 200 includes forming (202) a stator core and a rotor. As provided herein, the stator core and the rotor can be formed by any feasible method. Additionally, in various embodiments, the stator core can be positioned outside and / or inside the rotor.

[0096] At (204), the method includes forming a winding, which can include forming a tube at (206), the tube having a channel defined therethrough at least in part. In some cases, forming the tube can further include forming one or more inner surface features within the channel at (208), the inner surface features being configurable to change pressure, change flow rate, change flow from laminar to turbulent (or vice versa), increase the surface area of the channel along the winding, thereby increasing the heat rejection performance of the winding, etc.

[0097] At (210), the method can include winding one or more wires around a surface of the tube, the surface being on a side of the tube opposite the channel. Additionally, winding can include positioning one or more wires around the surface of the tube to form a winding, where the tube defines a channel therethrough at least in part. In various embodiments, the one or more wires are separated from the channel by the tube. In some embodiments, the one or more wires can include stranded wires, the stranded wires including a plurality of strands intertwined to form the wire.

[0098] In step (212), the method can include operably coupling the winding to a stator core or a rotor core. Once the winding is coupled to one of the stator core or the rotor core, the method can include fluidly coupling a cooling system to the channel in step (214). In some embodiments, fluidly coupling the cooling system to the channel further includes fluidly coupling a pump and a heat exchanger in series between a supply line and a return line. In some cases, the method can include fluidly coupling the cooling system to the channel in step (216), including coupling the supply line to an end portion of the winding and coupling the return line to a second end portion of the winding.

[0099] In operation, heat is generated by the motor. Meanwhile, the cooling system operably coupled to the channel is configured to move a cooling fluid through the channel. As the cooling fluid moves through the channel, heat is received from the winding into the cooling fluid, and then the heat is at least partially removed from the cooling fluid outside the winding. Additionally, the cooling fluid can contact one or more inner surface features within the channel, which can create less laminar flow within the channel to increase heat transfer from the winding to the cooling fluid and / or increase the surface area of the winding to increase the amount of heat that can be transferred to the cooling fluid. The heated cooling fluid can be cooled by a heat exchanger that can be 23 located outside the winding.

[0100] Accordingly, a motor having the cooling system provided herein can improve the thermal performance of the motor by increasing the heat transfer coefficient (HTC) of the motor. By operating in accordance with one or more of these aspects, Figures 1 - 12 the motor provided in Figure 13The method 200 provided herein can provide a more efficient electric machine due to the reduced operating temperature. Thus, when operating as a generator, the electric machine can be capable of generating more electrical power, and / or when operating as a motor, it can use electrical power more efficiently. Alternatively, by being able to more effectively remove the heat generated within the electric machine windings, the size of the electric machine can be reduced. In some applications, the size (and mass) of the electric machine may be more important than the efficiency of the electric machine.

[0101] Other aspects of the present disclosure may be provided in the following clauses:

[0102] An electric machine, comprising: a stator core that defines a plurality of core slots in its surface; a winding that is at least partially positioned in one of the plurality of core slots, the winding including a tube and one or more wire strands, the tube defining a passage through at least a portion thereof, and the wires being arranged along the tube opposite the passage; and a cooling system that is operably coupled to the passage and is configured to move a cooling fluid through the passage.

[0103] The electric machine according to one or more of these clauses further comprises: a controller that is operably coupled to the cooling system and is configured to operate a pump of the cooling system.

[0104] The electric machine according to one or more of these clauses, wherein the one or more wire strands are configured as stranded wire strands having a plurality of strands.

[0105] The electric machine according to one or more of these clauses, wherein each of the plurality of strands is separately coated with an insulating layer.

[0106] The electric machine according to one or more of these clauses, wherein the one or more wire strands include a plurality of wire strands positioned around an outer surface of the tube, and wherein each of the plurality of wire strands includes an outer sheath.

[0107] The electric machine according to one or more of these clauses further comprises: a strip disposed around each of the plurality of wire strands, wherein the strip extends in a direction generally perpendicular to each of the plurality of wire strands.

[0108] The electric machine according to one or more of these clauses, wherein the passage includes a first passage and a second passage separate from the first passage.

[0109] The electric machine according to one or more of these clauses, wherein the one or more wire strands include a first group of wire strands positioned between the first passage and the second passage and a second group of wire strands positioned around the first passage, the second passage, and the first group of wire strands.

[0110] An electric machine according to one or more of these clauses, wherein the first set of wire strands belongs to a first specification, and the second set of wire strands belongs to a second specification, and the first specification is different from the second specification.

[0111] The electric machine according to one or more of these clauses further includes: one or more inner surface features within the channel.

[0112] An electric machine according to one or more of these clauses, wherein the tube is formed of a first material, and the one or more wire strands include a second material, and wherein the first material is the same as the second material.

[0113] An electric machine according to one or more of these clauses, wherein the tube is formed of a first material, and the one or more wire strands include a second material, and wherein the first material is different from the second material.

[0114] A method of manufacturing an electric machine, the method comprising: positioning one or more wire strands around a surface of a tube to form a winding, wherein the tube defines a channel through at least a portion thereof, and wherein the one or more wire strands are separated from the channel by the tube; operably coupling the winding to one of a stator core or a rotor of the electric machine; and fluidly coupling a cooling system to the channel.

[0115] The method according to one or more of these clauses, wherein each of the one or more wire strands is configured as a stranded wire having a plurality of strands.

[0116] The method according to one or more of these clauses, wherein fluidly coupling the cooling system to the channel includes coupling a supply line to an end portion of the winding and coupling a return line to a second end portion of the winding.

[0117] The method according to one or more of these clauses, wherein fluidly coupling the cooling system to the channel further includes fluidly coupling a pump and a heat exchanger in series between the supply line and the return line.

[0118] A winding assembly for an electric machine, comprising: a tube that defines a channel through at least a portion thereof, the tube being configured to be operably coupled to a stator or a rotor of the electric machine; and one or more wire strands positioned along the tube opposite the channel.

[0119] An electric machine according to one or more of these clauses, wherein the one or more wire strands are configured as stranded wires, and a cooling system is operably coupled to the channel and is configured to move a cooling fluid through the channel.

[0120] The electric machine according to one or more of these clauses, wherein one or more wires include a first set of wires and a second set of wires, and wherein the tube includes a first tube and a second tube.

[0121] The electric machine according to one or more of these clauses, wherein the second set of wires is positioned between the first tube and the second tube, and the first set of wires is positioned around the first tube, the second tube, and the second set of wires.

[0122] The techniques discussed herein relate to computer-based systems and actions taken by computer-based systems and information sent to and from computer-based systems. Those of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions among components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, storage, instructions, and applications can be implemented on a single system or distributed across multiple systems. The distributed components can run sequentially or in parallel.

[0123] Although specific features of various embodiments may be shown in some figures and not in others, this is merely for convenience. In accordance with the principles of the present disclosure, any feature of any figure can be referenced and / or claimed in combination with any feature of any other figure.

[0124] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any incorporated method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If these other examples include structural elements that are not different in literal language from the claims, or if these other examples include equivalent structural elements that are not substantially different in literal language from the claims, then these other examples are intended to be within the scope of the claims.

Claims

1. A motor, comprising: A stator core that defines a plurality of core slots in its surface; A winding that is at least partially positioned in one of the plurality of core slots, the winding including a tube and one or more wire rods, the tube defining a passage through at least a portion thereof, the wire rods being arranged to be opposite the passage along the tube, wherein the passage includes a first end portion and an opposite second end portion; A cooling system that includes a supply line operably coupled to the first end portion and a return line operably coupled to the second end portion and is configured to move a cooling fluid through the passage; One or more inner surface features within the passage, wherein the one or more inner surface features increase the Reynolds number of the cooling fluid moving through the passage; And An insulating circuit breaker provided along each of the supply line and the return line to prevent current from flowing from the winding to the cooling system.

2. The motor according to claim 1, further comprising: A controller operably coupled to the cooling system and configured to operate a pump of the cooling system.

3. The motor according to claim 1, wherein, The one or more wire rods are configured as stranded wire rods having a plurality of strands.

4. The motor according to claim 3, wherein, Each of the plurality of strands is individually coated with an insulating layer.

5. The motor according to claim 1, wherein, The one or more wire rods include a plurality of wire rods positioned around an outer surface of the tube, and each of the plurality of wire rods includes an outer sheath.

6. The motor according to claim 5, further comprising: A strip provided around each of the plurality of wire rods, wherein the strip extends in a direction substantially perpendicular to each of the plurality of wire rods.

7. The motor according to claim 1, wherein, The passage includes a first passage and a second passage separated from the first passage.

8. The electric machine according to claim 7, wherein, The one or more wire rods include a first group of wire rods positioned between the first passage and the second passage and a second group of wire rods positioned around the first passage, the second passage, and the first group of wire rods.

9. The electric machine according to claim 8, wherein, The first group of wire rods belongs to a first specification, and the second group of wire rods belongs to a second specification, and the first specification is different from the second specification.

10. The motor according to claim 1, wherein, The tube is formed of a first material, and the one or more wire rods include a second material, and wherein the first material is the same as the second material.

11. The motor according to claim 1, wherein, The tube is formed of a first material, and the one or more wire rods include a second material, and wherein the first material is different from the second material.

12. A method of manufacturing a motor, the method comprising: Positioning one or more wire rods around a surface of a tube to form a winding, wherein the tube defines a passage through at least a portion thereof, wherein the passage includes a first end portion and an opposite second end portion, and wherein the one or more wire rods are separated from the passage by the tube, wherein one or more inner surface features are formed within the passage, wherein the one or more inner surface features increase the Reynolds number of the cooling fluid moving through the passage; and; Operably coupling the winding to one of a stator core or a rotor of the motor; And Fluidly couple a cooling system to the channel, wherein the cooling system includes a supply line operably coupled to the first end portion and a return line operably coupled to the second end portion, and wherein an insulating breaker is provided along each of the supply line and the return line to prevent current from flowing from the winding to the cooling system.

13. The method according to claim 12, wherein, Each of the one or more wire rods is configured as a stranded wire rod having a plurality of strands.

14. The method according to claim 12, wherein, Fluidly coupling the cooling system to the channel includes coupling the supply line to one end portion of the winding and coupling the return line to the second end portion of the winding.

15. The method according to claim 14, wherein Fluidly coupling the cooling system to the channel further includes fluidly coupling a pump and a heat exchanger in series between the supply line and the return line.

16. A winding assembly for an electric machine, comprising: A tube defining a channel through at least a portion thereof, the tube being configured to be operably coupled to a stator or a rotor of the electric machine, wherein the channel includes a first end portion and an opposite second end portion; One or more wire rods positioned along the tube opposite the channel; A cooling system including a supply line operably coupled to the first end portion and a return line operably coupled to the second end portion, and configured to move a cooling fluid through the channel; One or more inner surface features within the channel, wherein the one or more inner surface features increase the Reynolds number of the cooling fluid moving through the channel; And Insulating breakers provided along each of the supply line and the return line to prevent current from flowing from the winding to the cooling system.

17. The electric machine according to claim 16, wherein, The one or more wire rods are configured as stranded wire rods, and the cooling system is operably coupled to the channel and configured to move a cooling fluid through the channel.

18. The motor according to claim 16, wherein, The one or more wire rods include a first group of wire rods and a second group of wire rods, and wherein the tube includes a first tube and a second tube.

19. The electric machine according to claim 18, wherein, The second group of wire rods is positioned between the first tube and the second tube, and the first group of wire rods is positioned around the first tube, the second tube, and the second group of wire rods.

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