Cooling system for an electric machine

Abstract

A cooling device for an electric machine includes a body, a plurality of channels defined in the body, and a manifold. The body extends from a first end to a second end and defines an outer surface, an inner surface, and a cavity interior to the inner surface. The cavity is configured to receive a motor winding of a motor. A plurality of channels extend from the first end to the second end. Each of the plurality of channels is disposed between the inner surface and the outer surface. The manifold defines a fluid port and is arranged to engage the body at one of the first end or the second end to form a fluid-tight chamber surrounding a plurality of channels from the cavity. The fluid seal chamber is in fluid communication with the fluid port.

Description

Technical Field

[0001] The present disclosure relates to gas turbine engines, and more particularly to an apparatus for cooling an electric machine in a gas turbine engine. 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. Furthermore, the core of the gas turbine engine typically includes a compressor section, a combustion section, a turbine section, and an exhaust section in a serial flow order.

[0003] Incorporating electric motors (e.g., generators) into propulsion engines to utilize the mechanical energy generated by the propulsion engines to generate electrical power can enhance aircraft performance. For example, the electrical power 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. When generating electrical power, the resistance of the electrical current of the electrical power generates heat. This generated heat further increases the resistance of the components of the electric motors, thereby reducing the amount of electrical power generated by the electric motors. Dissipating the generated heat can improve the generation of electrical power. 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 schematic cross-sectional view of a gas turbine engine according to an example embodiment of the present disclosure.

[0006] Figure 2 It is a schematic diagram of the front view of the motor of the gas turbine engine.

[0007] Figure 3 It is a three-dimensional diagram of the cooling device of the motor.

[0008] Figure 4 It is a perspective view of the cooling device body.

[0009] Figure 5A is a cross-sectional view of an exemplary arrangement of a body of a cooling device along line 5 - 5 .

[0010] Figure 5B is a cross-sectional view of another exemplary arrangement of a body of a cooling device along line 5 - 5 .

[0011] Figure 5C is a cross-sectional view of another exemplary arrangement of a body of a cooling device along line 5 - 5 .

[0012] Figure 6Ais a perspective view of an exemplary cooling device.

[0013] Figure 6B is a perspective view of another exemplary cooling device.

[0014] Figure 6C is a perspective view of another exemplary cooling device.

[0015] Figure 7 is a perspective view of another exemplary cooling device.

[0016] Figure 8A is a cross-sectional view of the cooling device along line 8-8.

[0017] Figure 8B is a cross-sectional view of another cooling device.

[0018] Figure 8C is a cross-sectional view of another cooling device.

[0019] Figure 9A yes Figures 8B-8C A perspective view of an exemplary unit cell of a cooling device is shown.

[0020] Figure 9B yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0021] Figure 9C yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0022] Figure 9D yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0023] Figure 9E yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0024] Figure 9F yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0025] Figure 9G yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0026] Figure 9H yes Figures 8B-8C A perspective view of another exemplary unit cell of the cooling device is shown.

[0027] Figure 10A is a perspective view of another exemplary cooling device.

[0028] Figure 10B is a perspective view of another exemplary cooling device.

[0029] Figure 10C is a perspective view of another exemplary cooling device.

[0030] Figure 11 This is a schematic diagram of the motor's axial direction.

[0031] Figure 12 is a side cross-sectional view of the motor.

[0032] Figure 13A is a side cross-sectional view of another exemplary electric machine.

[0033] Figure 13B is a side cross-sectional view of another exemplary electric machine.

[0034] Figure 13C is a side cross-sectional view of another exemplary electric machine.

[0035] Figure 14 This is another axial schematic diagram of the motor.

[0036] Figure 15 is a side cross-sectional view of the motor.

[0037] Figure 16A is a side cross-sectional view of another exemplary electric machine.

[0038] Figure 16B is a side cross-sectional view of another exemplary electric machine.

[0039] Figure 16C is a side cross-sectional view of another exemplary electric machine.

[0040] Figure 17 This is another axial schematic diagram of the motor. DETAILED DESCRIPTION

[0041] 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 present disclosure.

[0042] The word "exemplary" is used herein to mean "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, all embodiments described herein should be considered exemplary unless specifically stated otherwise.

[0043] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0044] 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, and "downstream" refers to the direction toward which the fluid is flowing.

[0045] As used herein, the terms “first,” “second,” and “third,” and other ordinal numbers are used to distinguish one component from another and are not intended to indicate the position or importance of each component.

[0046] This disclosure generally relates to cooling electric machines in gas turbine engines. During operation, electric machines, such as motors and generators, generate heat. This heat can interfere with the operation of the electric machine, such as 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 lifespan of the electric machine.

[0047] Liquid coolant provides heat transfer through convection. Providing liquid coolant in solid channels (such as pipes, tubes, or sleeves) that contact the wires in the stator can directly dissipate heat from the wires. The wires dissipate heat to the solid surface of the channel, and the liquid coolant flows along the channel to extract heat from the solid surface. Because the liquid coolant does not directly contact the wires, coolant leakage is reduced while providing the beneficial heat transfer characteristics of convection cooling. Using this device to cool the stator and rotor can improve the operation of the motor. More specifically, the device improves temperature uniformity in the wires, stator, and rotor, especially during high-speed operation, thereby increasing the power density of the motor.

[0048] 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, referred to herein as “three-stream engine 100 ”, is provided. Figure 1 The tri-flow engine 100 can be mounted to an aircraft, such as a fixed-wing aircraft, and can generate thrust for propelling the aircraft. The tri-flow engine 100 is a "tri-flow engine" because its architecture provides three different streams of airflow that generate thrust during operation.

[0049] 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 speaking, 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.

[0050] The three-flow engine 100 includes a turbine 120 and a fan section 150 positioned upstream thereof. Generally, the turbine 120 includes a compressor section, a combustion section, a turbine section, and an exhaust section in a serial flow order. Specifically, as shown in FIG. Figure 1 As shown, the turbine 120 includes an engine core and a core cowling 122 annularly surrounding the engine core. The engine core and the core cowling 122 define an annular core inlet 124. The core cowling 122 further surrounds and supports a supercharger or low-pressure (LP) compressor 126 for pressurizing air entering the turbine 120 through the core inlet 124. A high-pressure (HP), multi-stage, axial-flow compressor (referred to herein as the HP compressor 128) receives the pressurized air from the LP 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.

[0051] The high-energy combustion products flow downstream from the combustor 130 to a high-pressure turbine 132. The high-pressure turbine 132 drives the HP compressor 128 via a first shaft, or HP shaft 136. In this regard, the high-pressure turbine 132 is drivingly coupled to the HP compressor 128. The high-energy combustion products then flow to the 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 LP 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 HP shaft 136. After driving each of the turbines 132, 134, the combustion products exit the turbine 120 through the core exhaust nozzle 140 to generate propulsive thrust. Thus, the turbine 120 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 fairing 122 in the radial direction R.

[0052] The fan section 150 includes a main fan 152. Figure 1 In the illustrated embodiment, the main fan 152 is an open rotor or non-ducted main fan 152. However, in other embodiments, the main fan 152 may be ducted, for example, by a fan housing or nacelle circumferentially surrounding the main fan 152. As shown, the main 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, main fan 152 is drivingly coupled to low pressure turbine 134 via LP shaft 138. Main fan 152 may be directly coupled to LP shaft 138, for example, in a direct drive configuration. Alternatively, as Figure 1 As shown, the main 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.

[0053] In addition, 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 main 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.

[0054] The fan section 150 further 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 cowling 170.

[0055] The fan cowling 170 annularly surrounds at least a portion of the core cowling 122 and is generally positioned outboard of the core cowling 122 in the radial direction R. Specifically, a downstream section of the fan cowling 170 extends over a forward portion of the core cowling 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 positioned generally outboard of the core duct 142 in the radial direction R. The fan cowling 170 and the core cowling 122 are connected together and are formed by a plurality of substantially radially extending, circumferentially spaced struts 174 ( Figure 1 The struts 174 may each have an aerodynamic profile to guide the air flowing therethrough. In addition to the struts 174, other struts may be used to connect and support the fan cowling 170 and / or the core cowling 122.

[0056] 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 forward end of the fan cowling 170 and is positioned between the main fan 152 and the fan guide vane array 160 in the axial direction A. The inlet duct 180 is an annular duct positioned inboard of the fan cowling 170 in 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 cowling 122 into the core duct 142 and the fan duct 172. The inlet duct 180 is wider in the radial direction R than the core duct 142. The inlet duct 180 is also wider in the radial direction R than the fan duct 172.

[0057] 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 ). Each mid-fan blade 192 has a root and a tip and a span defined therebetween. The mid-fan blades 192 are rotatable, for example, about the longitudinal axis 112. The mid-fan 190 is drivingly coupled to the low-pressure turbine 134 via the LP shaft 138. The mid-fan blades 192 may be arranged at equal circumferential spacing about the longitudinal axis 112. The mid-fan blades 192 are annularly surrounded or ducted by the fan cowling 170. In this regard, the mid-fan 190 is positioned inside the fan cowling 170 in the radial direction R. Furthermore, for this example embodiment, the mid-fan 190 is positioned within the inlet duct 180, upstream of the core duct 142 and the fan duct 172.

[0058] Thus, air flowing through inlet duct 180 passes over mid-fan blades 192 and is accelerated downstream thereof, particularly at the tips of mid-fan blades 192. At least a portion of the air accelerated by mid-fan blades 192 flows into fan duct 172 and is ultimately discharged through fan exhaust nozzle 178 to generate propulsive thrust. Furthermore, at least a portion of the air accelerated by mid-fan blades 192 flows into core duct 142 and is ultimately discharged through core exhaust nozzle 140 to generate propulsive thrust. Typically, mid-fan 190 is a compression device positioned downstream of engine inlet 182. Mid-fan 190 is operable to accelerate air entering fan duct 172 or a secondary bypass passage.

[0059] However, it should be understood that the exemplary 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 turbine 120 may have any other number and arrangement of shafts, spools, compressors, turbines, etc. Further, in other exemplary embodiments, the three-stream engine 100 may alternatively be configured as a ducted turbofan engine (including an outer nacelle surrounding the main fan 152 and a portion of the turbine 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 main fan 152); a dual-flow gas turbine engine (which may not include a fan duct 172); and the like.

[0060] Further, for Figure 1 In the embodiment shown, the three-stream engine 100 includes an electric motor 200 operatively coupled to its rotating components. In this regard, the three-stream engine 100 is an aviation hybrid electric propulsion machine. 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 stator assembly 202 and a rotor assembly 204 rotatable within the stator assembly 202. The electric motor 200 can be directly mechanically coupled to the LP shaft 138, as shown, or alternatively, the electric motor 200 can be indirectly mechanically coupled to the LP shaft 138, such as through a gearbox. Further, 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.

[0061] In some embodiments, motor 200 may be an electric motor operable to drive or power 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.

[0062] It should be appreciated that the gas turbine engine may have any other suitable configuration besides the above-described three-flow engine 100. Such configurations may include ducted, direct drive, fixed pitch, turboprop, etc.

[0063] Now refer to Figure 2 , provides a schematic front view of electric motor 200. As described above, electric motor 200 includes a stator assembly 202 and a rotor assembly 204. Stator assembly 202 includes a stator core 206 defining a plurality of stator slots 208, and rotor assembly 204 includes a rotor core 210 defining a plurality of rotor slots 212. Stator slots 208 and rotor slots 212 house windings (not shown) through which current is supplied or induced. As described above, during operation of electric motor 200, the windings generate heat, which increases resistance in the windings and reduces the overall output of electric motor 200. Electric motor 200 includes a plurality of cooling devices 214, one for each of stator slots 208 and rotor slots 212, to cool the windings, stator core 206, and rotor core 210 therein. It will be appreciated that in addition to cooling devices 214, electric motor 200 may also include other devices for transferring heat away from stator assembly 202 and rotor assembly 204, such as cooling plates (not shown).

[0064] Now refer to Figure 3 , provides a perspective view of one of the cooling devices 214 of the motor 200, as shown Figure 2 As shown in FIG. 3 , the cooling device 214 extends in the axial direction A, which is aligned with the axial direction A of the three-stream engine 100 .

[0065] The cooling device 214 includes a body 216 extending from a first end 218 to a second end 220, a plurality of channels 222 defined in the body 216, an inlet manifold 224 disposed at the first end 218 of the body 216, and an outlet manifold 226 disposed at the second end 220 of the body 216. Coolant flows from a coolant supply (not shown) through the cooling device 214 to cool the windings disposed in the stator slots 208 or the rotor slots 212. More specifically, the coolant flows into the inlet manifold 224, flows through the channels 222 from the first end 218 to the second end 220, and flows out of the outlet manifold 226 back to the coolant supply.

[0066] The body 216 defines an outer surface 228, an inner surface 230, and a cavity 232 within the inner surface 230. The outer surface 228 contacts the stator core 206 or the rotor core 210. The cavity 232 is configured to accommodate windings of the electric machine 200, which are wrapped by the inner surface 230.

[0067] The channel 222 extends from the first end 218 to the second end 220 and is located between the inner surface 230 and the outer surface 228. The channel 222 is fluidly connected to the inlet manifold 224 to receive the coolant and is fluidly connected to the outlet manifold 226 to deliver the coolant. As described in more detail below, the channel 222 can be formed in one of a variety of configurations, such as by drilling, boring, additive manufacturing, or a combination thereof.

[0068] An inlet manifold 224 provides coolant from a coolant supply to the channels 222. The inlet manifold 224 defines a fluid port 234 through which the coolant supply provides coolant. The inlet manifold 224 is attached to the body 216 at a first end 218. More specifically, the inlet manifold 224 is shaped to surround the channels 222 at the first end 218 of the body 216 by forming a fluid-tight friction fit with an outer surface 228, thereby inhibiting leakage of coolant. The inlet manifold 224 defines a cavity that is continuous with the cavity 232 of the body 216 to allow the windings to pass therethrough. The inlet manifold 224 can provide secondary cooling for the windings.

[0069] The outlet manifold 226 receives coolant from the channels 222. The outlet manifold 226 defines fluid ports 236 through which coolant flows from the channels 222 back to the coolant supply. The outlet manifold 226 is attached to the body 216 at the second end 220, forming a fluid-tight friction fit with the outer surface 228. When the inlet manifold 224 and the outlet manifold 226 are attached to the body 216, they form a fluid-tight chamber that surrounds the plurality of channels 222 from the cavity 232. The fluid-tight chamber is in fluid communication with the fluid ports 234, 236 of the inlet manifold 224 and the outlet manifold 226 to provide coolant to the channels 222, thereby cooling the windings, without leaking coolant into the cavity 232. The outlet manifold 226 defines a cavity that is continuous with the cavity 232 of the body 216, allowing the windings to pass therethrough. The outlet manifold 226 can provide secondary cooling for the windings.

[0070] Now refer to Figure 4 , a three-dimensional view of another body 240 of the cooling device 214 is provided. Figure 4 The exemplary body 240 may be Figure 3The exemplary body 216 is configured in substantially the same manner, and therefore, the same or similar numbers can refer to the same or similar components. It should be understood that the same or similar numbers can refer to the same or similar components throughout the drawings.

[0071] Figure 4 The body 240 includes an outer sleeve 242, an inner sleeve 244, and a plurality of connectors 246 extending between the outer sleeve 242 and the inner sleeve 244 and connecting the outer sleeve 242 to the inner sleeve 244. The outer sleeve 242 defines the outer surface 228 of the body 240, and the inner sleeve 242 defines the inner surface 230 of the body. The inner sleeve 244 defines a cavity 232, and the motor windings (not shown) are housed in the cavity 232. A plurality of channels 248 are defined between the outer sleeve 242 and the inner sleeve 244 and between the connectors 246 to allow coolant to pass therethrough. By forming the body 240 with the outer sleeve 242 and the inner sleeve 244, the channels 248 are defined by the connectors 246, which can be arranged to provide a specified coolant flow through the body 240. The connectors 246 provide structural support, linking the outer sleeve 242 to the inner sleeve 244.

[0072] More specifically, now refer to Figures 5A-5C , shows a cross-sectional view of an exemplary arrangement of the cooling device 214. The cross-sectional view is taken along Figure 4 Intercepted at line 5-5. Figure 5A A plurality of connectors 246 are shown that define a single passage 248 for coolant. Figure 5B A plurality of dividers 250 are shown, arranged diagonally between the outer sleeve 242 and the inner sleeve 244 , defining triangular shaped passages 252 for the coolant. Figure 5C A plurality of dividers 254 are shown, which are in the form of pins or fins and are arranged in a straight line between the outer sleeve 242 and the inner sleeve 244, defining a flow pattern 256 for the coolant. A plurality of windings 260 are disposed in the cavity 232 of each cooling device 214. In this context, a "divider" is a structure disposed between the outer sleeve 242 and the inner sleeve 244 and altering the flow of the coolant.

[0073] like Figure 4 and Figure 5A As shown, the connector 246 is located at several locations between the outer sleeve 242 and the inner sleeve 244. The connector 246 is located at the first end 218 of the body 240 and the second end 220 of the body 240 ( Figure 4 ) to fix the outer sleeve 242 to the inner sleeve 244. Figure 4As shown, the connector 246 does not extend from the first end 218 to the second end 220, but rather terminates midway in the body 240. In this form, the remaining space between the outer sleeve 242 and the inner sleeve 244 forms a single channel 248 that allows coolant to flow unimpeded from the first end 218 to the second end 220. In the channel 248, the coolant can flow around the inner sleeve 244 to absorb heat from the windings 260.

[0074] like Figure 5B As shown, the divider 250 extends diagonally between the outer sleeve 242 and the inner sleeve 244 to form a triangular channel 252. The divider 250 extends from the first end 218 to the second end 220 ( Figure 4 ), and the coolant flows through the channel 252 without flowing around the inner sleeve 244. The triangular shape of the channel 252 provides additional contact surface area for the coolant. The separator 250 absorbs heat from the inner sleeve 244 (transferred from the winding 260), and the coolant flows over the surface of the separator 250 to transfer heat from the separator 250. By increasing the surface area of ​​the separator 250, the contact with the coolant is increased, thereby increasing the heat transferred from the winding 260.

[0075] Additionally or alternatively, the dividers 250 may define other patterns not shown, such as a curved shape, a U-shape, a spiral pattern, or combinations thereof. It will be appreciated that a particular pattern may be selected based on the specific heat transfer characteristics of the cooling device 214.

[0076] like Figure 5C As shown, the divider 254 extends vertically or horizontally between the outer sleeve 242 and the inner sleeve 244 to form a flow pattern 256. The divider 254 extends along the outer sleeve 242 and the inner sleeve 244 from the first end 218 to the second end 220 ( Figure 4 ) are arranged in a lattice or grid pattern, and the coolant flows through the flow pattern 256. Figure 5B Compared to separator 250 , separator 254 provides a larger surface area and creates more flow turbulence, further increasing heat transfer from winding 260 .

[0077] Now refer to Figures 6A-6C , a perspective view of an exemplary body of a cooling device is provided. Figures 6A-6C The cooling device body can also be Figure 4 The body 240 is configured in a similar manner.

[0078] Figure 6A A body 270 is shown having a divider 272 extending along a straight line in the axial direction A from the first end 218 to the second end 220 . Figure 6BA body 274 is shown having a divider 276 extending along a serpentine line from the first end 218 to the second end 220 . Figure 6C A body 278 is shown having a divider 280 extending along a helical line from the first end 218 to the second end 220 .

[0079] like Figure 6A As shown, a plurality of dividers 272 extend along a straight line along the axial direction A from the first end 218 of the body 270 to the second end 220 of the body 270. The dividers 272 form straight channels 282 for allowing coolant to flow in the axial direction A without flowing around the body 270. The straight channels 282 allow coolant to flow directly from the first end 218 to the second end 220, improving heat transfer from the windings by increasing convective heat transfer and increasing coolant flow rate. Figures 5A-5C ).

[0080] like Figure 6B As shown, a plurality of dividers 276 extend along a serpentine line from the first end 218 of the body 274 to the second end 220 of the body 274. The dividers 276 form a serpentine channel 284 that undulates between the outer sleeve 242 and the inner sleeve 244. The serpentine channel allows the coolant to flow in a radial direction toward the inner sleeve 244, thereby receiving heat from the inner sleeve 244. The coolant then flows in a radial direction toward the outer sleeve 242, receiving heat from the outer sleeve 242. The coolant then flows back and forth between the inner sleeve 244 and the outer sleeve 242 as the coolant flows from the first end 218 to the second end 220. The serpentine motion of the coolant creates localized flow turbulence, thereby increasing the interaction of the coolant with the outer sleeve 242 and the inner sleeve 244, thereby increasing cooling of the electric machine 200.

[0081] like Figure 6C As shown, a plurality of dividers 280 extend along a spiral line from the first end 218 of the body 278 to the second end 220 of the body 278. The dividers 280 form a spiral channel 286 extending around the body 278. The spiral channel 286 is more convenient than a straight channel (such as Figure 6A The channels 282 shown are longer, which increases heat transfer from the windings.

[0082] Now refer to Figure 7 , a perspective view of another exemplary cooling device 290 is provided. Figure 7 An exemplary cooling device may be used with Figure 4-6C One or more of the exemplary cooling devices are configured in a similar manner.

[0083] However, for Figure 7 An exemplary embodiment of Figure 7 The body 292 of the cooling device 290 is not as Figure 4-6CThe embodiment of the present invention includes an outer sleeve 242 and an inner sleeve 244, but is a one-piece structure having a channel 294 formed between an outer surface 296 and an inner surface 298. Coolant flows from a first end 300 of the body 292 to a second end 302 of the body 292 through the channel 294, thereby transferring coolant from the winding ( Figures 8A-8C ) heat. Inlet manifold 224 ( Figure 3 ) may be attached to the body 292 at a first end 300, and the outlet manifold 226 ( Figure 3 ) can be attached to the body 292 at the second end 302.

[0084] Now refer to Figures 8A-8C , provides along Figure 7 A cross-sectional view of exemplary aspects of cooling device 290 along line 8-8 in FIG. Figure 8A is a cross-sectional view of a solid body 292 having a channel 294 formed between an outer surface 296 and an inner surface 298 . Figure 8B is a cross-sectional view of a body 306 formed of a plurality of unit cells 308 . Figure 8C is a cross-sectional view of a body 310 having a platform 312 extending through the cavity 304. Each cooling device 290 has a plurality of windings 314 disposed therein.

[0085] like Figure 8A As shown, body 292 is a solid, unitary structure having a channel 294 formed therein. Body 292 includes an outer surface 296 and an inner surface 298. Inner surface 298 defines a cavity 304, with winding 314 disposed within cavity 304. Channel 294 is defined between outer surface 296 and inner surface 298. Channel 294 extends from a first end 300 of body 292 to a second end 302 of body 292. By way of example, body 292 may be extruded as a solid, unitary piece, and channel 294 may be bored, drilled, cut, or otherwise removed. Alternatively, body 292 may be cast in a mold that forms channel 294 simultaneously with the rest of body 292. Still alternatively, body 292 may be additively manufactured, such as by laser metal deposition, laser sintering, laser powder bed fusion, or another suitable process. Channel 294 may have any suitable shape, such as cylindrical, triangular, linear, serpentine, spiral, or a combination thereof.

[0086] like Figure 8BAs shown, the body 306 includes a plurality of unit cells 308. As will be described in more detail below, each unit cell 308 includes a microchannel 316 that forms a portion of one of the channels 294. The unit cells 308 are fused together to form the body 306 as a unitary structure, and the microchannels 316 are fluidly connected to each other to form the channels 294. By forming the body 306 from a plurality of unit cells 308, the channels 294 can have a more complex geometry than channels formed by drilling, boring, etc., thereby increasing the surface area for heat transfer.

[0087] like Figure 8C As shown, the inner surface 298 of the body 310 includes a first side 318 and a second side 320 opposite the first side 318 across the cavity 304 in which the winding 314 is disposed. A platform 312 extends through the cavity 304 from the first side 318 to the second side 320, and the platform 312 defines one or more of the plurality of channels 294. The platform 312 provides coolant to the winding 314 closer to the center of the cavity 304, thereby improving heat transfer from the winding 314 farther from the inner surface 298. Figure 8B Like the illustrated body, the body 310 (including the platform 312) is formed from a plurality of unit cells 308 that include microchannels 316 that form the passages 294 to provide coolant therethrough. Figure 8C The body 310 of FIG. 3 includes two platforms 312 , and it should be understood that the body 310 may include a different number of platforms, such as one, three, or more.

[0088] Additionally or alternatively, the platform 312 can extend from the top side 319 of the body 310 to the bottom side 321 of the body 310, aligned with the first side 318 and the second side 320. Additionally or alternatively, the platform 312 can extend between any or all of the first side 318, the top side 319, the second side 320, or the bottom side 321.

[0089] Figures 8B-8C The bodies 306, 310 shown in the figures include a single layer of unit cells 308. In another form not shown in the figures, the body can be formed from multiple layers of unit cells 308 to increase the thickness of the body. Part or all of the length of the body can include these multiple layers to achieve specific heat transfer performance and mechanical load constraints.

[0090] refer to Figures 9A-9H , provides Figures 8B-8C A perspective view of an exemplary unit cell 308 of bodies 306, 310 is shown in FIG. Figure 9A is a perspective view of the unit cell 308 , wherein the microchannels 316 open into four of the six faces 322 of the unit cell 308 . Figure 9B yes Figure 9A 308 is a cross-sectional view of a unit cell. Figure 9C is a perspective view of the unit cell 308 , wherein the microchannels 316 open into four of the six faces 322 of the unit cell 308 . Figure 9D yes Figure 9C FIG. 3 is a cross-sectional view of a unit cell 308 showing a central pillar 324 therein. Figure 9E is a perspective view of a unit cell 308 , wherein microchannels 316 lead to all six faces 322 of the unit cell 308 . Figure 9F yes Figure 9E 308 is a cross-sectional view of a unit cell. Figure 9G is a perspective view of the unit cell 308 with microchannels 316 opening into all six faces 322 of the unit cell. Figure 9H yes Figure 9G FIG. 3 is a cross-sectional view of a unit cell 308 showing a central pillar 324 therein.

[0091] Now refer to Figures 9A-9B , the unit cell 308 has a generally cubic shape with six rectangular faces 322 that define the exterior surfaces of the unit cell 308. The unit cell 308 defines microchannels 316 in four of the six faces 322 of the unit cell 308. The microchannels 316 preferentially allow coolant to flow from a first surface 326 to an opposing surface 328 and an adjacent surface 330 of the unit cell 308. This coolant flow also occurs at the unit cell 308. Figure 9B 308 . The coolant can flow between any of the surfaces 326 , 328 , 330 , such that any of the surfaces 326 , 328 , 330 can function as an inlet or outlet. The merging and diverging of flows within the unit cell 308 improves heat transfer. The microchannels 316 are in fluid communication with the microchannels 316 of adjacent unit cells 308 , and the microchannels 316 allow coolant to flow through the bodies 306 , 310 from the first end 300 to the second end 302 in a two-dimensional grid or lattice pattern.

[0092] Now refer to Figures 9C-9D , the unit cell 308 includes a central column 324 to increase the turbulence of the coolant flow. In this form, the microchannel 316 preferentially allows the coolant to flow from the first surface 326 to one of the two adjacent surfaces 330 ( Figure 9D (indicated by arrows in the figure), and less flow to the opposite surface 328. When in fluid communication with the microchannels 316 of adjacent unit cells 308, the microchannels 316 allow the coolant to flow through the bodies 306, 310 in a two-dimensional diagonal or diamond pattern. It should be understood that when the bodies 306, 310 have a single layer of unit cells 308, a Figures 9A-9D The unit cell 308 is formed so that the coolant does not leak into the cavity 304.

[0093] Now refer to Figures 9E-9F, the unit cell 308 defines microchannels 316 in all six faces 322 of the unit cell 308. In this configuration, the microchannels 316 are junctions that combine two or more incoming streams into a single combined stream or split a single incoming stream into two or more outgoing streams. More specifically, in the embodiment shown, the junction includes a first inlet 332, a second inlet 334, and an outlet 336. The junction is arranged to combine the coolant flowing through the first inlet 332 with the coolant flowing through the second inlet 334 into a combined coolant flow through the outlet 336, as shown. Figure 9F It should be understood that the unit cell 308 may include up to five inlets and up to five outlets, where the total number of inlets and outlets is six to correspond to the six faces 322 of the unit cell 308. Figures 9A-9B Like the unit cells 308 in FIG. 3 , the microchannels 316 provide coolant flow through the bodies 306 , 310 in a three-dimensional grid or lattice pattern.

[0094] Now refer to Figures 9G-9H , the unit cell 308 includes a central column 324 to direct the coolant to the adjacent surface 330. Figures 9E-9F Like the unit cell 308 of FIG. 3 , the microchannel is a junction including a first inlet 332, a second inlet 334, and an outlet 336. The junction combines the coolant flowing through the first inlet 332 with the coolant flowing through the second inlet 334 into a combined coolant flow through the outlet 336, as shown in FIG. Figure 9H It should be understood that the unit cell 308 may include up to five inlets and up to five outlets, where the total number of inlets and outlets is six to correspond to the six faces 322 of the unit cell 308. Figures 9C-9D Like the unit cells 308 of the embodiment, the microchannels provide coolant flow through the body in a three-dimensional diagonal or diamond pattern. When the body 306, 310 has multiple layers of unit cells 308, the microchannels can be used. Figures 9E-9H The unit cell 308 is configured to allow the coolant to flow in three dimensions.

[0095] Now refer to Figures 10A-10C , provides perspective views of other exemplary cooling devices. Figures 10A-10C The cooling device can be used with Figure 4-8C One or more of the cooling devices are configured in a similar manner.

[0096] Figure 10A 3 is a perspective view of a cooling device 340 having an inlet clamp 342 and an outlet clamp 344 . Figure 10B is a perspective view of a cooling device 346 having fluid ports 348 of a manifold 350 located within a first end 352 of a body 354 of the cooling device 346 . Figure 10Cis a perspective view of a cooling device 356 comprising a single manifold 358 attached to a first end 352 of a body 354. For clarity, Figures 10A-10B Passages extending through the cooling devices 340, 346 are present but not shown.

[0097] like Figure 10A As shown, cooling device 340 includes an inlet clamp 342 attached to inlet manifold 360 and an outlet clamp 344 attached to outlet manifold 362. Inlet clamp 342 and outlet clamp 344 each engage one of stator core 206 or rotor core 210, forming a friction fit that inhibits movement of cooling device 340. Inlet clamp 342 and outlet clamp 344 secure cooling device 340 in stator slot 208 or rotor slot 212.

[0098] like Figure 10B As shown, the manifold 350 includes a fluid port 348 located at an interior portion of a first end 352 of the body 354. By positioning the fluid port 348 at an interior portion of the first end 352, the manifold 350 is aligned with other components of other cooling devices 340, 346, 356 disposed in other stator slots 208 or rotor slots 212, such as the rotor slots 212. Figure 10A The inlet clamps 342 are spaced apart as shown. This provides additional patterns for the windings. The location of the fluid ports 348 can reduce the pressure drop of the coolant within the cooling device 346, thereby reducing the pumping power required to make the coolant flow.

[0099] like Figure 10C As shown, the manifold 358 at the first end 352 of the body 354 can serve as an inlet and outlet for the coolant. More specifically, the manifold 358 includes an inlet port 364 that provides coolant to the body 354 and an outlet port 366 that transmits coolant from the body 354. A channel 368 defined in the body 354 extends in the axial direction A to the second end 370 and then returns to the first end 352 in the axial direction A, thereby allowing the coolant to flow forward and backward in the axial direction A. The manifold 358 may include a baffle 372 that separates the coolant entering through the inlet port 364 from the coolant flowing out through the outlet port 366. Figure 10C In the example shown, coolant flows forward and backward once through body 354. It should be understood that passage 368 can be defined to allow coolant to flow through body 354 more than once, such as three times, five times, seven times, or any suitable number of times.

[0100] Now refer to Figure 11, provides an axial schematic diagram of electric machine 380. As described above, stator assembly 202 of electric machine 200 includes stator core 206 and a plurality of cooling devices 214 disposed in stator slots 208 of stator core 206. Rotor assembly 204 is disposed radially inwardly of stator assembly 202, and in this exemplary embodiment, rotor assembly 204 does not include any cooling devices 214. Rotor assembly 204 includes rotor core 210 and shaft 382. Figure 11 The exemplary motor 380 can be used with Figure 2 The exemplary electric machines 200 are configured in substantially the same manner, and thus, like numbers may refer to like or similar components as described above.

[0101] As described above, each cooling device 214 includes a respective inlet manifold 224 disposed at the first end 218 of the stator core 206 and a respective outlet manifold 226 disposed at the second end 220 of the stator core 206. The electric machine 200 includes a radial inlet manifold 384 fluidly connected to the inlet manifold 224 of each of the cooling devices 214 and a radial outlet manifold 386 fluidly connected to the outlet manifold 226 of each of the cooling devices 214. The radial inlet manifold 384 provides coolant from a coolant supply 388 to each of the cooling devices 214, and the radial outlet manifold 386 transfers coolant from each of the cooling devices 214 back to the coolant supply 388. The cooling devices 214 are connected to each other through the radial inlet manifold 384 and the radial outlet manifold 386 in a "parallel flow" configuration, i.e., each cooling device 214 communicates coolant with the radial inlet manifold 384 and the radial outlet manifold 386 without communicating with any other cooling device 214. The parallel flow configuration reduces temperature variations among the plurality of cooling devices 214 and reduces coolant pressure drop.

[0102] refer to Figure 12 , provides a side cross-sectional view of the electric machine 380. A radial inlet manifold 384 provides coolant to each of the stator slots via a cooling device (not shown for clarity). The coolant flows through each of the stator slots 208 to a radial outlet manifold 386. Because the cooling device 214 (not shown) is connected in a parallel flow configuration, the radial inlet manifold 384 provides coolant to each of the stator slots 208 substantially simultaneously, and the radial outlet manifold 386 receives coolant from each of the stator slots 208 substantially simultaneously.

[0103] like Figures 13A-13C , side cross-sectional views of other exemplary electric machines are provided. Figure 13A An electric machine 390 is shown having a radial inlet manifold 384 and a radial outlet manifold 386 that deliver coolant to the cooling device 214 in the rotor assembly 204 . Figure 13B An electric machine 392 is shown having a first radial inlet manifold 384A and a first radial outlet manifold 386A that communicate coolant between a coolant supply 388 and the cooling device 214 in the stator assembly 202 , and a second radial inlet manifold 384B and a second radial outlet manifold 386B that communicate coolant between the coolant supply 388 and the cooling device 214 in the rotor assembly 204 . Figure 13C An electric machine 394 is shown having a first radial inlet manifold 384A and a first radial outlet manifold 386A that communicate coolant between a first coolant supply 388A and the cooling device 214 in the stator assembly 202 , and second radial inlet manifolds 384B and a second radial outlet manifold 386B that communicate coolant between a second coolant supply 388B and the cooling device 214 in the rotor assembly 204 .

[0104] refer to Figure 13A Coolant supply 388 provides coolant to radial inlet manifold 384 via first rotary fluid coupling 398 and receives coolant from radial outlet manifold 386 via second rotary fluid coupling 400. First rotary fluid coupling 398 and second rotary fluid coupling 400 are connectors disposed in shaft 382 that fluidly connect coolant supply 388 to radial inlet manifold 384 and radial outlet manifold 386 when shaft 382 and rotor core 210 rotate. First rotary fluid coupling 398 includes an inlet 402, an outlet 404 in fluid communication with radial inlet manifold 384, and a passage 406 defined in shaft 382 connecting inlet 402 to outlet 404. Second rotary fluid coupling 400 includes an inlet 408 in fluid communication with radial outlet manifold 386, an outlet 410, and a passage 412 defined in shaft 382 connecting inlet 408 to outlet 410.

[0105] Alternatively, not shown, the inlet 402 and the outlet 404 may be separate rotary fluid couplings that communicate via the passage 406. Likewise, the inlet 408 and the outlet 410 may be separate rotary fluid couplings that communicate via the passage 412.

[0106] As the shaft 382 rotates, the inlet 402 of the first rotary fluid coupling 398 and the outlet 410 of the second rotary fluid coupling 400 rotate into engagement with the coolant supply 388. Coolant flows through the inlet 402 of the first rotary fluid coupling 398, through the passage 406, and out the outlet 404 to the radial inlet manifold 384, and then to the cooling devices 214 in the rotor slots 212. The coolant flows through the rotor slots 212 to the radial outlet manifold 386. The coolant then flows through the inlet 408 of the second rotary fluid coupling 400, through the passage 412, and out the outlet 410 to the coolant supply 388. The shaft 382 continues to rotate until the first rotary fluid coupling 398 and the second rotary fluid coupling 400 rotate out of engagement with the coolant supply 388, thereby stopping the flow of coolant. In this configuration, coolant flows only during a portion of the rotation of the rotor assembly 204.

[0107] refer to Figure 13B The coolant supply 388 delivers coolant between the first radial inlet manifold 384A, the first radial outlet manifold 386A, the second radial inlet manifold 384B, and the second radial outlet manifold 386B. More specifically, the coolant supply 388 communicates coolant directly with the first radial inlet manifold 384A and the first radial outlet manifold 386A to provide coolant to the cooling devices 214 in the stator slots 208 of the stator assembly 202, as shown. Figure 12 The coolant supply 388 further delivers the coolant to the second radial inlet manifold 384B and the second radial outlet manifold 386B via the first rotary fluid coupling 398 and the second rotary fluid coupling 400 to provide the coolant to the cooling device 214 in the rotor slot 212 of the rotor assembly 204, as shown. Figure 13B As shown. The coolant supply 388 can be provided with coolant through a first central inlet manifold 385 connected to the first radial inlet manifold 384A and the second radial inlet manifold 384B, and the coolant supply 388 can receive coolant through a second central inlet manifold 387 connected to the first radial outlet manifold 386A and the second radial outlet manifold 386B. The first central inlet manifold 385 and the second central inlet manifold 387 are non-rotating structures that transfer coolant to and from the coolant supply 388.

[0108] refer to Figure 13C, the motor 394 includes a first coolant supply 388A to provide coolant to the stator assembly 202, and a second coolant supply 388B to provide coolant to the rotor assembly 204. More specifically, the first coolant supply 388A is directly connected to the first radial inlet manifold 384A and the first radial outlet manifold 386A, and the second coolant supply 388B is connected to the second radial inlet manifold 384B using a first rotary fluid coupling 398 and to the second radial outlet manifold 386B using a second rotary fluid coupling 400. By having two separate coolant supplies 388A, 388B, the coolant can flow through the stator assembly 202 and the rotor assembly 204 at different rates, amounts, temperatures, chemical compositions, or combinations thereof. Specifically, Figure 13C Coolant is shown flowing through the stator assembly 202 in a direction along the axial direction A, and the coolant is shown flowing through the rotor assembly 204 in a direction opposite to the axial direction A. That is, the coolant in the stator assembly 202 flows in a direction opposite to the coolant in the rotor assembly 204 (i.e., a counter-flow configuration), which may provide additional heat transfer through the electric machine 394. It should be appreciated that the first coolant supply 388A and the second coolant supply 388B may provide coolant in the same direction (i.e., a co-flow configuration) through the stator assembly 202 and the rotor assembly 204.

[0109] Now refer to Figure 14 , provides an axial schematic diagram of electric machine 420. Stator assembly 202 of electric machine 420 includes stator core 206 and a plurality of cooling devices 214 disposed in stator slots 208 of stator core 206. Rotor assembly 204 is disposed radially inward of stator assembly 202, and in this exemplary embodiment, rotor assembly 204 does not include any cooling devices 214. Rotor assembly 204 includes rotor core 210 and shaft 382.

[0110] The cooling devices 214 are arranged in a "serial flow" configuration, wherein the outlet manifold of a first cooling device 214 is in fluid communication with the inlet manifold of an adjacent cooling device 214. Rather than providing coolant to all of the cooling devices 214, thereby splitting the flow of coolant, the coolant supply 388 is in fluid communication only with the inlet manifold 224 of a first of the cooling devices 214 and the outlet manifold 226 of a last of the cooling devices 214. In this configuration, a full flow rate of coolant is provided sequentially to each of the cooling devices 214. Each cooling device 214 provides coolant from its respective outlet manifold 226 to the inlet manifold 224 of the next adjacent cooling device 214, thereby providing coolant to each cooling device 214 in a serial flow path from the first of the cooling devices 214 to the last of the cooling devices 214. Figure 14In the example of FIG. 2 , it will be appreciated that the inlet manifold 224 and the outlet manifold 226 are indicated by arrows indicating the direction of flow of the coolant. The serial flow configuration reduces flow variations among the plurality of cooling devices 214 .

[0111] refer to Figure 15 , provides a side cross-sectional view of the electric machine 420. As described above, in a serial flow configuration, the coolant supply 388 provides coolant directly to the cooling devices 214 in the stator assembly 202 without the need for an additional manifold. In the serial flow configuration, the coolant flows through the first of the cooling devices 214 and then sequentially through the cooling devices 214 surrounding the stator assembly 202 until it flows through the last of the cooling devices 214 and returns to the coolant supply 388.

[0112] like Figures 16A-16C , side cross-sectional views of other exemplary electric machines are provided. Figure 16A Electric machine 422 is shown with coolant supply 388 providing coolant to cooling device 214 in rotor assembly 204 . Figure 16B Electric machine 424 is shown with coolant supply 388 providing coolant to cooling device 214 in stator assembly 202 and cooling device 214 in rotor assembly 204 . Figure 16C Electric machine 426 is shown having a first coolant supply 388A that provides coolant to cooling device 214 in stator assembly 202 and a second coolant supply 388B that provides coolant to cooling device 214 in rotor assembly 204 .

[0113] like Figure 16A As shown, coolant supply 388 provides coolant to cooling device 214 in rotor assembly 204. Figure 13A As shown, the electric machine includes a first rotary fluid coupling 398 disposed in the shaft 382 and a second rotary fluid coupling 400 disposed in the shaft 382. The coolant supply 388 provides coolant to an inlet 402 of the first rotary fluid coupling 398, and the coolant flows through a channel 406 to an outlet 404. The outlet 404 is fed to an inlet manifold 224 ( ) of the first cooling device 214 in the rotor assembly 204. Figure 14 The coolant flows sequentially to each of the cooling devices 214 of the rotor assembly 204 and then flows through the cooling devices 214 through the rotor slots 212 of the rotor core 210 .

[0114] The coolant then flows through the cooling devices 214 in sequence to the outlet manifold 226 ( Figure 14), to the inlet 408 of the second rotary fluid coupling 400. A passage 412 allows coolant to flow from the inlet 408 to the outlet 410, which provides the coolant to the coolant supply 388. As the shaft 382 rotates, the inlet 402 of the first rotary fluid coupling 398 rotates in and out of engagement with the coolant supply 388, thereby allowing coolant to flow only during a portion of the rotation of the shaft 382.

[0115] like Figure 16B As shown, the coolant supply 388 first provides coolant to the cooling device 214 in the stator assembly 202 and then to the cooling device 214 in the rotor assembly 204. Figure 13B As shown, the electric machine includes a first rotary fluid coupling 398 disposed in the shaft 382 and a second rotary fluid coupling 400 disposed in the shaft 382. The coolant supply 388 provides coolant to one of the cooling devices 214 of a given subassembly 202, which provides coolant to the other cooling devices 214 of the given subassembly 202 in a serial flow configuration.

[0116] The coolant then flows from the cooling device 214 of the stator assembly 202 to the inlet 408 of the second rotary fluid coupler 400, flows through the passage 412 to the outlet 410. The outlet 410 provides the coolant to one of the cooling devices 214 of the rotor assembly 204, which provides the coolant to the other cooling devices 214 of the rotor assembly 204 in a serial flow configuration. The coolant flows through the rotor assembly 204 to the inlet 402 of the first rotary fluid coupler 398, flows through the passage 406 to the outlet 404. The outlet 404 of the first rotary fluid coupler 398 is fluidly connected to the coolant supply 388. Figure 16B In the configuration, coolant flows in the axial direction A through the stator slots 208 to the second rotary fluid coupler 400 , and then flows counter to the axial direction A through the rotor slots 212 to the first rotary fluid coupler 398 .

[0117] like Figure 16C As shown, a first coolant supply 388A provides coolant to the cooling devices 214 in the stator assembly 202, and a second coolant supply 388B provides coolant to the cooling devices 214 in the rotor assembly 204. More specifically, the first coolant supply 388A is connected to the inlet manifold 224 of one of the cooling devices 214 in the stator assembly 202, which provides coolant in a serial flow configuration to the other cooling devices 214 in the stator assembly 202. The coolant flows through the stator assembly 202 to the outlet manifold 226 of one of the cooling devices 214, which provides coolant to the first coolant supply 388A.

[0118] The second coolant supply 388B is connected to an inlet 402 of the first rotating fluid coupling 398, which provides coolant to an outlet 404 through a passage 406. The outlet 404 of the first rotating fluid coupling 398 is connected to an inlet manifold 224 of one of the cooling devices 214 of the rotor assembly 204, which provides coolant to the other cooling devices 214 of the rotor assembly 204 in a serial flow configuration. The coolant flows through the rotor assembly 204 to an outlet manifold 226 of one of the cooling devices 214 of the rotor assembly 204, which provides coolant to an inlet 408 of the second rotating fluid coupling 400. The coolant flows through the passage 412 to an outlet 410, which provides coolant to the second coolant supply 388B. Figure 16C In the exemplary embodiment, coolant flows in an axial direction A (i.e., in the same direction) through the stator assembly 202 and through the rotor assembly 204. It should be understood that the coolant supplies 388A, 388B may provide coolant to the electric machine 426 in opposite directions (i.e., a counter-flow configuration).

[0119] Now refer to Figure 17 , provides an axial schematic diagram of motor 430. Stator assembly 202 of motor 430 includes stator core 206 and a plurality of cooling devices 214 disposed in stator slots 208 of stator core 206. Rotor assembly 204 is disposed radially inward of stator assembly 202 and, in this exemplary embodiment, does not include any cooling devices 214. Rotor assembly 204 includes rotor core 210 and shaft 382.

[0120] The cooling device 214 is arranged in a hybrid configuration that combines Figure 11 Parallel stream configuration and Figure 14 More specifically, the motor 430 includes a radial inlet manifold 384 that provides coolant from a coolant supply 388 to certain of the cooling devices 214, referred to herein as Figure 17 214I. Each inlet cooling device is in a parallel flow configuration with each other inlet cooling device 214I, and each inlet cooling device 214I is in a serial flow configuration with the other cooling devices in cooling devices 214. That is, each inlet cooling device 214I provides coolant to the other cooling devices 214 in a serial flow configuration.

[0121] As the coolant flows through the stator assembly 202, the coolant flows from certain of the cooling devices 214 to the radial outlet manifold 386. The cooling devices 214 in fluid communication with the radial outlet manifold 386 are referred to herein as Figure 172. The outlet cooling device 214O receives coolant from the other cooling devices 214 in a serial flow configuration and transmits the coolant to the radial outlet manifold 386. The radial outlet manifold 386 then transmits the coolant to the coolant supply 388. The mixed flow configuration provides improved temperature uniformity and flow variation within the multiple cooling devices 214.

[0122] The coolant supply 388 can be part of a closed-loop cooling system (not shown) arrangement having a pump, an external heat exchanger, and a coolant reservoir. The coolant can be of any suitable type, such as liquid helium, liquid nitrogen, water, oil, supercritical carbon dioxide, or a combination thereof. In operation, cold coolant is pumped to the motor 200 to cool the windings and core. The hot coolant leaving the motor 200 then passes through one or more heat exchangers to transfer thermal energy to a heat dissipation fluid. The cold coolant leaving the heat exchanger is then returned to the pump in a closed loop. The closed loop can be connected to the coolant reservoir to enable startup and transient scenarios. The cold heat dissipation fluid can be fuel, liquid hydrogen, or air obtained from a source such as a fuel tank or LP compressor. The hot heat dissipation fluid leaving the heat exchanger can be sent to the combustion chamber.

[0123] By incorporating a cooling device into an electric motor, liquid coolant can be provided to cool the windings disposed in the stator and rotor without leaking into the stator slots or rotor slots. More specifically, the channels of the cooling device allow coolant to flow through the stator slots and rotor slots, thereby absorbing heat from the windings without flooding the stator or rotor. Furthermore, by forming a fluid-tight chamber for the coolant to reduce or inhibit contact between the coolant and the windings, the electric motor may eliminate the need for additional components that would be used to flood the stator or rotor with coolant. Consequently, the cooling device improves the efficiency and lifespan of the electric motor.

[0124] Further aspects are provided by the subject matter of the following clauses:

[0125] A cooling device for an electric motor defining an axial direction, the cooling device comprising: a body extending from a first end to a second end, the body defining an outer surface, an inner surface, and a cavity within the inner surface, the cavity being configured to receive motor windings of the electric motor; a plurality of channels defined in the body, the plurality of channels extending from the first end to the second end, each of the plurality of channels being disposed between the inner surface and the outer surface; and a manifold defining a fluid port, wherein the manifold is arranged to engage the body at one of the first end or the second end to form a fluid-tight chamber surrounding the plurality of channels from the cavity, wherein the fluid-tight chamber is in fluid communication with the fluid port.

[0126] The cooling device of the preceding clause further comprises a second manifold defining fluid ports, wherein the second manifold is arranged to engage the body at the other of the first end or the second end to form a fluid-tight chamber surrounding the plurality of channels from the cavity.

[0127] A cooling device as recited in any one of the preceding clauses, wherein the body further comprises a plurality of dividers extending from the outer surface to the inner surface and from the first end to the second end, wherein the plurality of channels are defined between adjacent ones of the plurality of dividers.

[0128] A cooling device as claimed in any one of the preceding clauses, wherein the plurality of dividers each extend along a straight line along the axial direction from the first end to the second end.

[0129] A cooling device as in any preceding clause, wherein the plurality of dividers each extend along a serpentine line from the first end to the second end.

[0130] The cooling device of any of the preceding clauses, wherein the plurality of dividers each extend along a helical line from the first end to the second end.

[0131] A cooling device as claimed in any preceding clause, wherein the body comprises a plurality of unit cells, each unit cell defining a microchannel, wherein the plurality of channels are defined by respective microchannels of the plurality of unit cells.

[0132] A cooling device as claimed in any preceding clause, wherein one or more layers of the plurality of unit cells are provided between the inner surface and the outer surface.

[0133] The cooling device of any of the preceding clauses, wherein each unit cell defines a plurality of surfaces, the microchannel of each unit cell extends between at least two of the plurality of surfaces, and the microchannel is in fluid communication with at least one microchannel of at least one adjacent unit cell of the plurality of unit cells.

[0134] A cooling device according to any of the preceding clauses, wherein at least one of the microchannels is a junction, the junction comprising a first inlet, a second inlet, and an outlet, wherein the junction is arranged to combine fluid flowing through the first inlet with fluid flowing through the second inlet into a combined fluid flow through the outlet.

[0135] The cooling device of any of the preceding clauses, wherein each unit cell defines a plurality of surfaces and a center, and wherein the bonding portion is defined on the surface of the unit cell or at the center of the unit cell.

[0136] A cooling arrangement as claimed in any preceding clause, further comprising a coolant supply in fluid communication with the fluid port of the manifold.

[0137] A cooling device as claimed in any preceding clause, wherein the body comprises an outer sleeve defining the outer surface and an inner sleeve defining the inner surface and the cavity, and wherein the plurality of channels are defined between the outer sleeve and the inner sleeve.

[0138] A cooling device according to any of the preceding clauses, wherein the manifold is arranged to join the body at the same side as a second manifold, and wherein the manifold and the second manifold are adjacent to each other, wherein the cooling device further includes a partition defined between the manifold and the second manifold.

[0139] A cooling device according to any of the preceding clauses, wherein the inner surface includes a first side and a second side opposite the first side, and wherein the body further includes a platform extending from the first side to the second side, and wherein the plurality of channels includes one or more channels defined in the platform.

[0140] A cooling device according to any of the preceding clauses, wherein the manifold defines an inner portion at one of the first end or the second end of the body and defines an outer portion at one of the first end or the second end of the body, and wherein the fluid port is defined at the inner portion or the outer portion.

[0141] A cooling device according to any one of the preceding clauses, wherein the coolant is a fluid in a liquid, gaseous, supercritical or cryogenic state.

[0142] A cooling device as claimed in any preceding clause, wherein the body comprises an outer sleeve defining the outer surface and an inner sleeve defining the inner surface and the cavity, and wherein a plurality of cylindrical features or pins extend from the outer sleeve to the inner sleeve.

[0143] An electric machine for a gas turbine engine defining an axial direction, the electric machine comprising: a stator assembly including a stator core defining a plurality of stator slots in the axial direction; a rotor assembly including a rotor core defining a plurality of rotor slots in the axial direction, the rotor assembly being rotatable within the stator assembly; and a plurality of cooling devices, each of the plurality of cooling devices being disposed in one of the plurality of stator slots or one of the plurality of rotor slots. Each of the plurality of cooling devices comprises: a body extending from a first end to a second end, the body defining an outer surface, an inner surface, and a cavity within the inner surface; a plurality of channels defined in the body, the plurality of channels extending from the first end to the second end, each of the plurality of channels being disposed between the inner surface and the outer surface; an inlet manifold attached to the body at the first end; and an outlet manifold attached to the body at the second end, wherein the inlet manifold, the outlet manifold, and the body form a fluid-tight chamber surrounding the plurality of channels from the cavity.

[0144] An electric machine as recited in any preceding clause, wherein the outlet manifold of a first one of the plurality of cooling devices is in fluid communication with the inlet manifold of an adjacent second one of the plurality of cooling devices.

[0145] An electric machine as recited in any preceding clause, wherein the outlet manifold of each of the plurality of cooling devices is in fluid communication with a respective inlet manifold of each adjacent one of the plurality of cooling devices to form a serial flow path.

[0146] The electric machine of any of the preceding clauses, further comprising a radial inlet manifold fluidly connected to the inlet manifold of at least one of the plurality of cooling devices and a radial outlet manifold fluidly connected to the outlet manifold of at least one of the plurality of cooling devices.

[0147] An electric machine as recited in any preceding clause, further comprising a plurality of windings disposed in each cavity of the plurality of cooling devices.

[0148] An electric machine as recited in any of the preceding clauses, wherein at least one of said plurality of cooling devices further comprises an inlet clamp attached to said inlet manifold and an outlet clamp attached to said outlet manifold, wherein said inlet clamp engages one of said stator core or said rotor core and said outlet clamp engages one of said stator core or said rotor core.

[0149] An electric machine as claimed in any one of the preceding clauses, further comprising a rotary fluid coupling arranged to provide coolant to one of the plurality of cooling devices provided in one of the plurality of rotor slots.

[0150] An electric machine as claimed in any preceding clause, wherein the rotary fluid coupling is arranged to be rotated into engagement with a coolant supply to receive the coolant and is arranged to be rotated out of engagement with the coolant supply to cease receiving the coolant.

[0151] An electric machine as recited in any preceding clause, wherein the outlet manifold of one of the plurality of cooling devices is fluidly connected to the inlet manifold of an adjacent one of the plurality of cooling devices to form a mixed flow path.

[0152] An electric machine as claimed in any one of the preceding clauses, wherein the plurality of cooling devices provided in the plurality of stator slots are in fluid communication with the plurality of cooling devices provided in the plurality of rotor slots.

[0153] An electric machine as claimed in any one of the preceding clauses, wherein the rotor assembly further comprises a shaft, and wherein a passage defined in the shaft is in fluid communication with the rotary fluid coupling.

[0154] An electric machine as claimed in any preceding clause, further comprising one or more coolant supplies in fluid communication with the cooling arrangement.

[0155] A gas turbine engine includes a turbine, the turbine including a compressor, a combustor, and a turbine arranged in a serial flow sequence; and an electric machine defining an axial direction, the electric machine including a stator and a rotor capable of rotating within the stator. The electric machine further includes a plurality of cooling devices, each of the plurality of cooling devices being arranged to pass through the stator in the axial direction or to pass through the rotor in the axial direction. Each of the plurality of cooling devices includes a body extending from a first end to a second end in the axial direction, the body defining a cavity and a plurality of channels extending from the first end to the second end. A plurality of windings are provided in the cavity of each of the plurality of cooling devices.

[0156] The gas turbine engine of any one of the preceding clauses, further comprising a manifold configured to engage the body to surround the plurality of passages from the cavity.

[0157] The gas turbine engine according to any of the preceding clauses, further comprising a rotary fluid coupling arranged to provide coolant to one of the plurality of cooling devices provided in one of the plurality of rotor slots.

[0158] A gas turbine engine according to any one of the preceding clauses, wherein the rotary fluid coupling is arranged to rotate into engagement with a coolant supply to receive the coolant and is arranged to rotate out of engagement with the coolant supply to cease receiving the coolant.

[0159] This written description uses examples to disclose the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the present disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the present 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 cooling device for an electric motor with a limited axial direction, characterized in that: The cooling device comprises: a body extending from a first end to a second end, the body defining an outer surface, an inner surface, and a cavity within the inner surface, the cavity being configured to receive a motor winding of the motor; a plurality of channels defined in the body, the plurality of channels extending from the first end to the second end, each of the plurality of channels being disposed between the inner surface and the outer surface; and a manifold defining fluid ports, wherein the manifold is arranged to engage the body at one of the first end or the second end, wherein, when the manifold engages said one of the first end or the second end, the manifold and the inner surface of the body form a fluid-tight chamber surrounding the plurality of channels from the cavity, The fluid-tight chamber is in fluid communication with the fluid port.

2. The cooling device according to claim 1, characterized in that Further including: A second manifold defines a fluid port, wherein the second manifold is arranged to engage the body at the other of the first end or the second end to form the fluid-tight chamber with the manifold and the inner surface of the body.

3. The cooling device according to claim 1, characterized in that The body further comprises a plurality of dividers extending from the outer surface to the inner surface and from the first end to the second end, wherein the plurality of channels are defined between adjacent ones of the plurality of dividers.

4. The cooling device according to claim 3, characterized in that wherein each of the plurality of dividers extends along a straight line along the axial direction from the first end to the second end.

5. The cooling device according to claim 3, characterized in that Each of the plurality of dividers extends along a serpentine line from the first end to the second end.

6. The cooling device according to claim 3, characterized in that The plurality of dividers each extend along a spiral line from the first end to the second end.

7. The cooling device according to claim 1, characterized in that wherein the body comprises a plurality of unit cells, each unit cell defining a microchannel, wherein the plurality of channels are defined by respective microchannels of the plurality of unit cells.

8. The cooling device according to claim 7, characterized in that Each unit cell defines a plurality of surfaces, the microchannel of each unit cell extends between at least two of the plurality of surfaces, and the microchannel is in fluid communication with at least one microchannel of at least one adjacent unit cell in the plurality of unit cells.

9. The cooling device according to claim 7, characterized in that At least one of the microchannels is a junction comprising a first inlet, a second inlet, and an outlet, wherein the junction is arranged to combine fluid flowing through the first inlet with fluid flowing through the second inlet into a combined fluid flow through the outlet.

10. The cooling device according to claim 1, characterized in that Further included is a coolant supply in fluid communication with the fluid port of the manifold.

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