Cooling the stator housing of the motor

Abstract

An electric motor may include a stator assembly and one or more rotors, the stator assembly including a stator housing, the one or more rotors being coupled to the stator by a rotor shaft assembly. The stator housing may include a cooling structure having a plurality of cooling body portions and a plurality of cooling ducts defined by the plurality of cooling body portions. A method of forming a stator housing for an electric motor may include additively manufacturing a stator housing including a cooling structure defining a fluid domain, coupling a source of a working fluid to the stator housing and introducing the working fluid into the fluid domain defined by the cooling structure, and sealing the cooling structure with respect to the working fluid contained within the fluid domain of the cooling structure. A method of cooling an electric motor may include heating a working fluid in the fluid domain and flowing the working fluid through the fluid domain, and transferring heat from the cooling structure to a cooling fluid that flows along one or more cooling surfaces contacting a surface of the electric motor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 072,432, filed on August 31, 2020, the contents of which are incorporated herein by reference in their entirety as if set forth verbatim. Technical Field

[0003] The present disclosure relates generally to electric machines, and more particularly to cooling electric machines. Background Art

[0004] The electric motor includes operating elements that generate heat when the electric motor is operated. Cooling features may be provided for the electric motor. However, some electric motors may have limited space available for cooling features.

[0005] Typically, structural and cooling features of an electric machine design compete for the same space adjacent to the force and heat generating components of the electric machine, and a trade-off between power density and performance must be made.

[0006] Therefore, a need exists for improved electric machines, such as electric machines with improved cooling, as well as improved methods of manufacturing components of electric machines and improved methods of cooling electric machines. Summary of the invention

[0007] Technical Solution 1. A motor, comprising:

[0008] a stator assembly comprising a stator housing; and

[0009] one or more rotors coupled to the stator by a rotor shaft assembly;

[0010] The stator housing includes a winding ring and a cooling structure, the winding ring defines a plurality of winding slots respectively configured to receive electromagnetic elements, the cooling structure is arranged in at least a portion of the winding ring, wherein the cooling structure includes a plurality of cooling body parts and a plurality of cooling ducts defined by the plurality of cooling body parts.

[0011] Technical Solution 2. The motor according to Technical Solution 1, wherein the stator housing comprises:

[0012] A plurality of cooling fins, and at least a portion of the cooling structure disposed within at least a portion of the plurality of cooling fins.

[0013] Technical Solution 3. The motor according to Technical Solution 1, wherein the cooling structure comprises:

[0014] A vapor chamber includes an internal wicking structure and one or more vapor channels.

[0015] Technical Solution 4. The motor according to Technical Solution 1, wherein the cooling structure comprises:

[0016] One or more evaporator sections and one or more condenser sections.

[0017] Technical Solution 5. The motor according to Technical Solution 1, wherein the winding ring comprises:

[0018] an inner annular portion, an outer annular portion, and a plurality of winding flanges disposed between the inner annular portion and the outer annular portion; and

[0019] The cooling structure comprises:

[0020] One or more evaporator sections and one or more condenser sections, wherein the one or more evaporator sections are disposed around the plurality of winding flanges, and wherein the one or more condenser sections are disposed around the inner annular section and / or the outer annular section.

[0021] Technical Solution 6. The electric machine according to Technical Solution 1, wherein the winding ring comprises a plurality of cooling fins, and wherein the cooling structure comprises:

[0022] one or more evaporator sections disposed about the cooling structure at locations relatively distal to the plurality of cooling fins; and

[0023] One or more condenser sections are disposed about the cooling structure at locations relatively proximal to the plurality of cooling fins.

[0024] Technical Solution 7. The electric machine according to Technical Solution 6, wherein the plurality of cooling fins define at least part of the one or more condenser parts of the cooling structure.

[0025] Technical Solution 8. The motor according to Technical Solution 1, wherein the cooling structure comprises:

[0026] One or more evaporator sections and one or more condenser sections, wherein the one or more evaporator sections and / or the one or more condenser sections have a variable location that depends at least in part on one or more temperature gradients of the cooling structure that may exist during operation of the electric machine.

[0027] Technical Solution 9. The electric machine according to Technical Solution 1, wherein the cooling structure defines a flow path configured to allow the working fluid to flow from the inlet to the outlet.

[0028] Technical Solution 10. The motor according to Technical Solution 1, wherein the cooling structure includes a lattice structure, a mesh structure, a wicking structure, and / or an agglomerated structure.

[0029] Technical Solution 11. An electric machine according to Technical Solution 1, wherein the cooling structure comprises an agglomerated structure, the agglomerated structure comprising sintered powder material and / or partially melted powder material from an additive manufacturing process for forming the stator housing.

[0030] Technical Solution 12. The motor according to Technical Solution 1, wherein the cooling structure comprises a steam chamber, and the steam chamber comprises a wicking structure and one or more steam channels.

[0031] Technical Solution 13. The electric machine according to Technical Solution 1, wherein the cooling structure includes a three-dimensional array of cooling body parts and cooling duct parts interspersed with each other.

[0032] Technical Solution 14. An electric motor according to Technical Solution 1, wherein the cooling structure comprises a random or semi-random structure of a lattice, mesh, wicking and / or agglomerated structure.

[0033] Technical Solution 15. An electric motor according to Technical Solution 1, wherein the stator housing comprises a single integrated component formed by an additive manufacturing process.

[0034] Technical Solution 16. A method for forming a stator housing for an electric motor, the method comprising:

[0035] additively manufacturing a stator housing including a cooling structure, the cooling structure defining a fluid domain;

[0036] coupling a source of working fluid to the stator housing and introducing working fluid into the fluid space defined by the cooling structure; and

[0037] sealing the cooling structure with respect to the working fluid contained within the fluid domain of the cooling structure;

[0038] The stator housing includes a winding ring and a cooling structure, the winding ring defines a plurality of winding slots respectively configured to receive electromagnetic elements, the cooling structure is arranged in at least a portion of the winding ring, wherein the cooling structure includes a plurality of cooling body parts and a plurality of cooling ducts defined by the plurality of cooling body parts.

[0039] Technical Solution 17. An electric motor according to Technical Solution 16, wherein the stator housing comprises a single integrated component.

[0040] Technical Solution 18. The method according to Technical Solution 16 comprises:

[0041] heating the working fluid and removing non-condensable gases from the fluid domain; and

[0042] The cooling structure is sealed with respect to the working fluid in a heated state.

[0043] Technical Solution 19. A method for cooling a motor, the method comprising:

[0044] operating an electric machine, the electric machine comprising a stator assembly, one or more rotors, a rotor shaft assembly coupling the one or more rotors to the stator assembly, and a plurality of operating elements comprising a plurality of electromagnetic elements, wherein the stator assembly comprises a stator housing, the stator housing comprising a winding annulus and a cooling structure, the winding annulus defining a plurality of winding slots respectively receiving corresponding electromagnetic elements of the plurality of electromagnetic elements, the cooling structure being disposed within at least a portion of the winding annulus, wherein the cooling structure comprises a plurality of cooling body portions and a plurality of cooling conduits defined by the plurality of cooling body portions, wherein the plurality of cooling conduits define a fluid domain containing a working fluid, and wherein operating the electric machine comprises the plurality of operating elements generating heat;

[0045] generating heat at least in part by the plurality of operating elements to heat the working fluid in the fluid domain and flow the working fluid through the fluid domain; and

[0046] Heat is transferred from the cooling structure to a cooling fluid that flows along one or more cooling surfaces, contacting surfaces of the electric machine.

[0047] Technical Solution 20. The method according to Technical Solution 19 comprises:

[0048] evaporating a working fluid at one or more evaporator portions of the cooling structure; and

[0049] A working fluid is condensed at one or more condenser portions of the cooling structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] A full and enabling disclosure including the best mode thereof to those skilled in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0051] Figure 1A schematically depicts a perspective view of an exemplary electric machine;

[0052] Figure 1B schematically depicts an exploded perspective view of an exemplary electric machine;

[0053] Figure 2 schematically depicting operating elements of an exemplary electric machine;

[0054] Figure 3A schematically depicting an exemplary stator assembly of an electric machine;

[0055] Figure 3B schematically depicts an exploded view of an exemplary stator assembly of an electric machine;

[0056] Figures 4A-4C schematically depicting an exemplary stator housing of a stator assembly;

[0057] Figures 5A-5C schematically depicts a partial cross-sectional view of an exemplary embodiment of a stator housing having a cooling structure disposed therein;

[0058] Figures 6A-6C schematically depicts a partial cross-sectional view of an additional exemplary embodiment of a stator housing having a cooling structure disposed therein;

[0059] Figures 7A-7C schematically depicting partial cross-sectional views of further exemplary embodiments of a stator housing having a cooling structure disposed therein;

[0060] Figures 8A-8G schematically depicts an exemplary steam chamber configuration that may be included in a cooling structure of a stator housing;

[0061] Fig.9A A flow chart describing an exemplary method of manufacturing a stator housing including a cooling structure is shown;

[0062] Figures 9B-9D schematically depicting a stator housing having a working fluid introduced into a fluid domain defined by a cooling structure of the stator housing; and

[0063] Fig.10 A flow chart depicting an exemplary method of cooling an electric machine is shown.

[0064] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the present disclosure. DETAILED DESCRIPTION

[0065] Reference will now be made in detail to exemplary embodiments of the subject matter of the present disclosure, one or more examples of which are shown in the accompanying drawings. Each example is provided by way of illustration and should not be construed as limiting the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made in the present disclosure without departing from the scope of the present disclosure. For example, a feature shown or described as part of one embodiment may be used together with another embodiment to produce yet another embodiment. Therefore, it is intended that the present disclosure covers such modifications and variations within the scope of the appended claims and their equivalents.

[0066] It is understood that the terms "upstream" and "downstream" refer to relative directions relative to the flow of fluid in a fluid channel. For example, "upstream" refers to the direction from which the fluid flows, while "downstream" refers to the direction to which the fluid flows. It is also understood that terms such as "top", "bottom", "outward", "inward", etc. are words of convenience and are not to be construed as limiting terms. As used herein, the terms "first", "second", and "third" may be used interchangeably to distinguish one component from another, and are not intended to indicate the location or importance of independent components. The terms "one" and "an" do not indicate a quantitative limitation, but rather indicate the presence of at least one of the referenced items.

[0067] Approximate language, as used herein throughout the specification and claims, may be applied to modify any quantitative expression that may permissibly vary without resulting in a change in the basic function to which it relates. Thus, a value modified by one or more terms, such as "approximately," "substantially," and "approximately," will not be limited to the precise value specified. In at least some cases, approximate language may correspond to the precision of an instrument used to measure a value, or the precision of a method or machine used to construct or manufacture a component and / or system. For example, approximate language may refer to within a 10% margin.

[0068] Here and throughout the specification and claims, range limitations are combined and / or interchanged, such ranges are identified and include all sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints are independently combinable with each other.

[0069] Exemplary embodiments of the present disclosure will now be described in more detail. Figure 1A and Figure 1BAn exemplary electric machine 100 is shown. The electric machine may include a stator assembly 102 and one or more rotors 104. The one or more rotors 104 may be coupled to the stator assembly 102 by a rotor shaft assembly 106 (such as via a rotor bearing assembly 107). The electric machine may include one or more cooling surfaces 108 (such as one or more stator cooling surfaces 110 and / or one or more rotor cooling surfaces 112) through which a cooling fluid 114 (such as cooling air) may flow and thereby cool the electric machine 100. The one or more cooling surfaces 108 may be disposed about a radially inward portion of the electric machine 100, such as, for example, at Figure 1A and Figure 1B . Additionally, or in the alternative, one or more cooling surfaces 108 may be disposed about a radially outward portion of the electric machine 100. For example, the one or more cooling surfaces may circumferentially surround the electric machine 100. In some embodiments, the circumferential perimeter of the electric machine 100 may define the cooling surfaces 108. In some embodiments, the cooling jacket 116 may define at least a portion of a cooling path for the cooling fluid 114 to flow past the one or more cooling surfaces 108.

[0070] like Figure 2 , an exemplary operating element 200 of the electric machine 100 may include a plurality of winding elements 202 and a plurality of magnet elements 204. Heat generated by the operating element 200 of the electric machine 100 may be transferred to the cooling fluid 114, which flows along one or more cooling surfaces 108, contacting surfaces of the electric machine, such as surfaces of the stator assembly 102 and / or surfaces of the rotor 104.

[0071] Figure 3A and Figure 3BAn exemplary stator assembly 102, 300 of an electric machine 100 is shown. The stator assembly 102, 300 may include a stator housing 302 and a plurality of electromagnetic elements 304 configured to fit into corresponding winding slots 306 of a plurality of winding slots 306 of the stator housing 302. The electromagnetic elements 304 may include teeth 305, winding material 307 wound around the teeth 305. By way of example, the winding material may include a plurality of wires, such as a wire harness. In some embodiments, the wire harness may be housed in an insulating material (not shown). The electromagnetic elements 304 may be secured in corresponding winding slots 306 via teeth fittings 308 (such as snap rings, retaining pins, clamps, etc.). The stator housing 302 may include a plurality of eddy current path interrupters 310 in communication with corresponding winding slots 306 of the winding slots 306. The eddy current path interrupters 310 block eddy currents caused by magnetic flux from the electric machine. The eddy current path interruption 310 may be located at a position of the stator housing 302 that interrupts a structural loop that may otherwise enhance eddy currents. The eddy current path interruption 310 may be disposed radially inwardly relative to the corresponding winding slot 306 and / or radially outwardly relative to the corresponding winding slot 306. The eddy current path interruption 310 may be configured to block and / or prevent the formation of a magnetic eddy current loop. The housing element 312 may be insertable into a corresponding eddy current path interruption 310 in a plurality of eddy current path interruptions 310. The stator housing 302 may include a plurality of cooling fins 314 disposed around one or more stator cooling surfaces 110. The cooling fins 314 may be configured to help dissipate heat from the operating element 200 of the motor 100. In some embodiments, a plurality of winding slots 306 of the stator housing 302 may be open to the rotor(s) 104. For example, in some embodiments, an assembled electric machine may include electromagnetic elements 304 directly facing rotor(s) 104 without a portion of stator housing 302 disposed therebetween.

[0072] The exemplary stator housing 302 is Figures 4A-4C . The stator housing 302 may be formed using an additive manufacturing process, such as a powder bed fusion process as described herein. The stator housing 302 may include a winding annulus 400 defining a plurality of winding slots 306 configured to receive the electromagnetic elements 304. The stator housing 302 may include a hub 402 configured to receive the rotor shaft assembly 106, such as via a rotor bearing assembly ( Figure 3B ). The winding ring 400 and the hub 402 may be secured to each other by a plurality of stator flanges 404. The stator flanges 404 may define at least some of the plurality of stator cooling surfaces 110. The winding ring 400 may include an inner ring portion 406, an outer ring portion 408, and a plurality of winding flanges 410 disposed between the inner ring portion 406 and the outer ring portion 408.

[0073] like Figure 4A As shown in FIG. 3 , the stator housing 302 may be constructed without the cooling fins 314. Figure 4B As shown in FIG. 3 , the stator housing 302 may include a plurality of cooling fins 314 disposed about a radially inward portion of the stator housing 302. For example, the cooling fins 314 may be disposed about a radially inward portion of the winding annulus 400 (such as an inner annular portion of the winding annulus 400). Figure 4C As shown in FIG. 1 , the stator housing may include a plurality of cooling fins 314 disposed about a radially outer portion of the stator housing 302. For example, the cooling fins 314 may be disposed about a radially outer portion of the winding annulus 400 (such as an outer annular portion of the winding annulus 400). Additionally or alternatively, as shown in FIG. Figure 4C , the stator housing 302 may include a plurality of cooling fins 314 disposed about a radially inward portion of the stator housing 302 and a radially outward portion of the stator housing 302. For example, a first plurality of cooling fins 314 may be disposed about a radially inward portion of the winding annulus 400 (such as an inner annular portion of the winding annulus 400), and a second plurality of cooling fins 314 may be disposed about a radially outward portion of the winding annulus 400 (such as an outer annular portion of the winding annulus 400).

[0074] The respective portions of the stator housing 302 may be formed integrally with each other, such as by additively manufacturing the respective portions of the stator housing 302 as a single integrated component. Additionally, or in the alternative, some of the portions of the stator housing 302 may be formed as separate components, such as in separate additive manufacturing operations, and such separate components may be fixed or secured to each other to form the complete stator housing 302.

[0075] Now turn to Figures 5A-5C , Figures 6A-6C , Figures 7A-7C as well as Figures 8A-8C , an exemplary cooling structure 500 will be described. As shown, at least a portion of the stator housing 302 may include a cooling structure 500 disposed therein. For example, one or more cooling structures 500 may be disposed within at least a portion of the winding ring 400. The cooling structure 500 may be disposed within at least a portion of the inner annular portion 406 of the winding ring 400, at least a portion of the outer annular portion 408 of the winding ring 400, and / or within at least a portion of one or more winding flanges 410. The cooling structure 500 may be disposed within at least a portion of one or more cooling fins 314. The cooling structure 500 may be configured to help transfer heat from the operating element 200 of the electric machine 100 to the cooling fluid 114, which flows along one or more cooling surfaces 108.

[0076] The cooling structure may be additively manufactured during the same additive manufacturing process used to form the stator housing 302. The cooling structure 500 may include a three-dimensional structure that defines a fluid domain. By way of example, the three-dimensional structure may define a fluid domain that includes a plurality of tortuous paths. The cooling structure 500 may include a hollow volume having an array of structural elements disposed therein, such as a lattice structure, a mesh structure, a wicking structure, an agglomerated structure, and the like. In some embodiments, the cooling structure 500 may include a sintered powder material and / or a partially melted powder material from an additive manufacturing process. At least a portion of the hollow volume of the cooling structure 500 may include a random or semi-random configuration of a lattice, mesh, wicking, and / or agglomerated structure.

[0077] The working fluid may be disposed within and / or flow through a plurality of passages defined by the cooling structure 500. The lattice, mesh, wicking, and / or agglomerated structures may be constructed and arranged to have a size that allows the working fluid to be transported through the cooling structure 500 via capillary action. In some embodiments, the cooling structure 500 may define a vapor chamber 502. The vapor chamber 502 may include an internal wicking structure 504 and / or one or more vapor channels 506. In some embodiments, the cooling structure 500 may include a vapor chamber 502 having an evaporator portion 508 and a condenser portion 510.

[0078] The evaporator portion 508 and the condenser portion 510 may be disposed about a defined area of ​​the cooling structure 500. Additionally, or in the alternative, the cooling structure 500 may include a vapor chamber 502 having the evaporator portion 508 and the condenser portion 510 with variable locations that depend on one or more temperature gradients of the cooling structure 500 that may exist during operation of the electric machine 100. For example, a relatively hot portion of the cooling structure 500 may operate as the evaporator portion 508, while a relatively cool portion of the cooling structure 500 may operate as the condenser portion 510.

[0079] In some embodiments, the cooling structure 500 may include one or more evaporator sections 508 disposed around one or more of the winding flanges 410. Additionally or in the alternative, the cooling structure 500 may include one or more condenser sections disposed around the inner annular portion 406 of the winding ring 400 and / or disposed around the outer annular portion 408 of the winding ring 400. In some embodiments, the cooling structure 500 may include one or more evaporator sections 508 disposed around the inner annular portion 406 of the winding ring 400 and / or disposed around the outer annular portion 408 of the winding ring 400. Additionally or in the alternative, the cooling structure 500 may include one or more condenser sections 510 disposed around one or more of the winding flanges 410. The winding flanges 410 may include one or more evaporator sections 508 and / or one or more condenser sections 510. The inner annular portion 406 of the winding annulus 400 may include one or more evaporator portions 508 and / or one or more condenser portions 510. The outer annular portion 408 of the winding annulus 400 may include one or more evaporator portions 508 and / or one or more condenser portions 510.

[0080] For example, in Figures 5A-5C As shown in FIG. 4 , the cooling structure 500 may substantially surround the entire winding ring 400 . Figure 5A The cooling structure 500 shown in FIG. 5 may be configured as a steam chamber 502. In some embodiments, Figures 5A-5C The winding annulus 400 shown in FIG. 4 may include one or more evaporator sections 508 disposed about at least a portion of the plurality of winding flanges 410 . Figures 5A-5C The winding ring 400 shown in FIG. 4 may include one or more condenser sections 510 disposed around at least a portion of the inner ring section 406 of the winding ring 400 and / or at least a portion of the outer ring section 408 of the winding ring 400. The specific locations of the evaporator section 508 and / or the condenser section 510 of the cooling structure 500 may depend at least in part on one or more operating temperatures of the winding ring 400, such as a temperature gradient within the winding ring 400.

[0081] The winding annulus may include an eddy current path interruption portion 310 that surrounds an outer annular portion 408 (eg, Figure 5A ), the inner annular portion 406 of the winding annulus (e.g., Figure 5B ), or both the outer annular portion 408 and the inner annular portion 406 of the winding annulus (e.g., Figure 5C) are disposed. In some embodiments, the location of the one or more evaporator portions 508 and / or the one or more condenser portions 510 may depend at least in part on the location of the vortex path interruption portion 310. For example, the one or more evaporator portions 508 may be disposed around a location of the cooling structure 500 that is relatively distal to the vortex path interruption portion 310. In addition, or in the alternative, the one or more condenser portions 510 may be disposed around a location of the cooling structure 500 that is relatively proximal to the vortex path interruption portion 310.

[0082] like Figures 6A-6C , in some embodiments, the winding ring 400 may include a plurality of cooling fins 314 disposed around an outer annular portion 408 of the winding ring 400 and / or an inner annular portion 406 of the winding ring 400. The cooling fins 314 may define at least a portion of the cooling structure 500. In some embodiments, the location of the one or more evaporator portions 508 and / or the one or more condenser portions 510 may depend at least in part on the location of the plurality of cooling fins 314. For example, the one or more evaporator portions 508 may be disposed around a location of the cooling structure 500 that is relatively distal to the plurality of cooling fins 314. In addition, or in the alternative, the one or more condenser portions 510 may be disposed around a location of the cooling structure 500 that is relatively proximal to the plurality of cooling fins 314. In some embodiments, the cooling fins may define the condenser portion 510 of the cooling structure 500.

[0083] like Figures 7A-7C, in some embodiments, the winding ring 400 may include a cooling structure 500 defining a flow path 700, the flow path 700 being configured to allow the working fluid to flow from the inlet 702 to the outlet 704. The flow path 700 may include a lattice structure or the like configured to cause the working fluid to follow a tortuous path between the inlet 702 and the outlet 704. In some embodiments, the cooling structure 500 may include one or more baffles 706 defining at least a portion of the flow path 700. The baffles 706 may be configured to guide the working fluid to pass along a serpentine path through the cooling structure 500. In some embodiments, the one or more baffles 706 may be disposed within a corresponding winding flange 410 of the plurality of winding flanges 410. For example, one or more baffles 706 disposed within the winding flange 410 may be configured to define a flow path that extends from the inner annular portion 406 of the winding annulus 400, through the winding flange 410 to the outer annular portion 408 of the winding annulus 400, and then from the outer annular portion 408 back through the winding flange 410 to the inner annular portion 406 of the winding annulus 400. Additionally, or in the alternative, one or more baffles 706 may be disposed within the outer annular portion 408 of the winding annulus 400 and / or within the inner annular portion of the winding annulus 400. For example, one or more baffles 706 disposed within the outer annular portion 408 may be configured to define a flow path that extends through the outer annular portion 408 in a clockwise direction, and then back through the outer annular portion 408 in a counterclockwise direction, or vice versa, such as between adjacent vortex path interruptions 310. One or more baffles 706 disposed within the inner annular portion 406 may be configured to define a flow path that extends clockwise through the inner annular portion 406 and then returns in a counterclockwise direction through the inner annular portion 406 , or vice versa, such as between adjacent vortex path interruptions 310 .

[0084] It will be recognized that Figures 5A-5C , Figures 6A-6C as well as Figures 7A-7C The exemplary stator housing 302 shown in FIG. 1 is provided by way of example only and is not intended to be limiting. In some embodiments, Figures 5A-5C , Figures 6A-6C and / or Figures 7A-7COne or more of the features shown in the figure can be combined with each other to provide further embodiments. For example, the stator housing 302 may include a cooling structure 500 having both a steam chamber 502 and a flow path 700, the flow path 700 being configured to allow a working fluid to flow from the inlet 702 to the outlet 704. The steam chamber 502 and the flow path 700 may be provided as separate cooling structures 500, such as physically separated cooling structures 500 and / or fluidly separated cooling structures 500. In addition, or in an alternative, the steam chamber 502 and the flow path 700 may be provided as a single integrated cooling structure, such as having a steam chamber 502 and a flow path 700 that are fluidly separated from each other and / or having a steam chamber 502 and a flow path 700 that are fluidly connected to each other.

[0085] Now refer to Figures 8A-8D , further describing the exemplary cooling structure 500. As shown, the exemplary cooling structure may include a cooling body 800 and a plurality of cooling conduits 802 at least partially defined by the cooling body 800. The cooling body 800 may include an array of structural elements, such as a lattice structure, a mesh structure, a wicking structure, an agglomerated structure, and the like. In some embodiments, the cooling body 800 may include an agglomerated structure comprising a sintered powder material and / or a partially melted powder material from an additive manufacturing process. At least a portion of the cooling body 800 may include a random or semi-random configuration of a lattice, mesh, wicking, and / or agglomerated structure. The plurality of cooling conduits 802 may include a tortuous path for a working fluid to flow through the cooling structure 500. In some embodiments, the cooling structure 500 may include a vapor chamber 502. The vapor chamber 502 may include a cooling body 800, which is constructed and arranged in the form of a wicking structure 504 that allows a working fluid to be transported through the cooling structure 500 via capillary action. For example, the lattice, mesh, wicking and / or agglomerated structures may be constructed and arranged with a size that provides a wicking structure 504 that allows capillary action. The vapor chamber 502 may include one or more of the cooling conduits 802 that are constructed and arranged in the form of one or more vapor channels 506.

[0086] like Figures 8A-8F , the working fluid within the cooling structure 500 may evaporate at one or more evaporator portions 508. The evaporated working fluid may travel along a vapor path 808 from the evaporator portion 508 through one or more of the cooling conduits 802 and / or the vapor channels 506 to the condenser portion 510. The working fluid may condense at the one or more condenser portions 510. The condensed working fluid may travel along a condensation path 810 from the condenser portion 510 through the cooling body 800 and / or the wicking structure 504 to the evaporator portion 508. The one or more cooling bodies 800 and / or the one or more wicking structures 504 may be disposed around an outer portion of the cooling structure 500 ( Fig. 8A and Figure 8B One or more cooling conduits 802 and / or one or more steam passages 506 may be disposed around an interior portion of the cooling structure 500 ( Fig. 8A and Figure 8B In addition, or in the alternative, one or more cooling conduits 802 and / or one or more steam passages 506 may be disposed around an outer portion of the cooling structure 500 ( Figure 8C and Fig.8D One or more cooling bodies 800 and / or one or more wicking structures 504 may be disposed around an interior portion of the cooling structure 500 ( Figure 8C and Fig.8D ).

[0087] like Figures 8E-8G As shown in FIG. 1 , the cooling structure 500 and / or the vapor chamber 502 may be configured in the form of a three-dimensional array of cooling body 800 portions and cooling conduit 802 portions interspersed with each other (such as a three-dimensional array of wicking structures 504 and vapor channels 506). For example, the three-dimensional array of cooling body 800 and / or wicking structures 504 may define a three-dimensional branching passage of cooling conduits 802 and / or vapor channels 506. The three-dimensional cooling structure 500 and / or the vapor chamber 502 (such as Figures 8E-8G 506 ) may include one or more evaporator portions 508 and / or one or more condenser portions 510 that are variably located within the vapor chamber 502, for example, based at least in part on the temperature and / or temperature gradient of the cooling structure 500. For example, when a portion of the cooling structure 500 exceeds a threshold temperature, a working fluid located proximate thereto may evaporate and travel through the cooling conduits 802 and / or the vapor passages 506. The evaporated working fluid may condense at a portion of the cooling structure that is below the threshold temperature, and then travel through the cooling body portion and / or the wicking structure via capillary action until it eventually reaches another portion of the cooling structure 500 that exceeds the threshold temperature. The specific location of the one or more evaporator portions 508 and / or the one or more condenser portions 510 may change during operation of the motor 100, such as under different operating conditions and / or when different portions of the cooling structure 500 discharge heat to the cooling fluid 114, the cooling fluid 114 flows along one or more cooling surfaces 108 (such as one or more stator cooling surfaces 110) of the stator housing 302.

[0088] Now turn to Fig.9A and Fig. 9B, an exemplary method 900 for forming a stator housing 302 for an electric machine 100 will be described. The stator housing 302 may be formed using an additive manufacturing process, such as a powder bed fusion process. As used herein, the term "additive manufacturing" generally refers to a manufacturing technique in which a component is manufactured in a layer-by-layer manner. The stator housing 302 may be formed using any desired additive manufacturing technique. In an exemplary embodiment, the stator housing 302 may be formed using an additive manufacturing technique, which includes a powder bed fusion (PBF) technique, such as a direct metal laser melting (DMLM) technique, an electron beam melting (EBM) technique, an electron beam sintering (EBS) technique, a selective laser melting (SLM) technique, a directional metal laser sintering (DMLS) technique, or a selective laser sintering (SLS) technique. In an exemplary PBF technique, thin layers of powdered material are sequentially applied to a build plane and then selectively melted or fused to each other in a layer-by-layer manner to form one or more three-dimensional objects. Additively manufactured objects are generally unitary in nature and may have various integrated sub-components.

[0089] In addition or alternatively, suitable additive manufacturing techniques include, for example, binder jetting technology, fused deposition modeling (FDM) technology, direct energy deposition (DED) technology, laser engineered net shaping (LENS) technology, laser net shaping manufacturing (LNSM) technology, direct metal deposition (DMD) technology, digital light processing (DLP) technology, reduction polymerization (VP) technology, photo-stereolithography (SLA) technology, and other additive manufacturing technologies using energy beams. Additive manufacturing technology can be generally described as the production of complex objects by building objects point by point, layer by layer (typically in the vertical direction); however, other production methods are contemplated and within the scope of the present disclosure. For example, although the discussion herein refers to the addition of materials to form continuous layers, the subject matter of the present disclosure can be practiced using any additive manufacturing technology or other manufacturing technology (including layer addition processes, layer subtraction processes, or hybrid processes).

[0090] The additive manufacturing process described herein can be used to form components using any suitable building material. For example, the building material can be a metal, a ceramic, or any other suitable building material. In an exemplary embodiment, the building material can be selected from a non-magnetic or weakly magnetic metal or metal alloy (such as titanium or a titanium alloy, aluminum or an aluminum alloy). In addition, or in an alternative, the building material can be selected from a metal or metal alloy with low electrical conductivity. Advantageously, such non-magnetic or weakly magnetic metals or metal alloys (and / or metals or metal alloys with low electrical conductivity) can exhibit a relatively low Lenz effect during operation of the motor 100. Such materials are sometimes referred to as "non-participating" materials because the materials do not generally participate in generating the electromagnetic force provided by the motor 100. The additive manufacturing process can utilize building materials in any suitable form (including solid, liquid, powder, sheet, wire, or any other suitable form).

[0091] Still refer to Figures 9A-9D , the exemplary method 900 may include, at block 902, additively manufacturing a stator housing 302, the stator housing 302 including a defined fluid domain 950 ( Fig. 9B ) of the cooling structure 500. The stator housing 302 may include a working fluid supply port 952 that provides a working fluid source 954 to a fluid domain 950 (defined by the cooling structure 500) Fig. 9C ) between the cooling structure 500. The exemplary method 900 may include coupling a working fluid source 954 to the stator housing 302 and introducing a working fluid 956 into a fluid domain 950 ( Fig. 9C By way of example, a working fluid source 954 may be coupled to a working fluid supply port 952 of the stator housing 302, such as via a supply hose 958. The exemplary method 900 may include sealing the cooling structure 500 at block 906 with a working fluid 956 contained within a fluid domain 950 of the cooling structure 500.

[0092] In some embodiments, the fluid domain 950 may be sealed with a patch 960, such as by adding molten material to the stator housing 302 to a portion of the cooling structure having the working fluid supply port 952. At least a portion of the fluid supply port 952 may be removed when sealing the cooling structure 500. The fluid domain 950 may be sealed under vacuum at a pressure level suitable for allowing the fluid domain to operate as a vapor chamber 502, so that the working fluid may evaporate and condense at a desired temperature corresponding to the expected operating conditions of the motor 100, for example. For example, the working fluid 956 may be heated to a suitable temperature (such as a boiling temperature), thereby purging non-condensable gases from the fluid domain 950 and / or the vapor chamber 502. The vapor chamber 502 may then be sealed with respect to the working fluid 956 in a heated state (such as while maintaining such heated conditions). The vacuum may be provided by allowing the working fluid 956 to cool. Any suitable working fluid 956 may be selected. Suitable working fluids include those having relatively high latent heat, relatively high surface tension, relatively high thermal conductivity, and a suitable boiling point commensurate with the expected operating conditions of the motor 100.

[0093] Now turn to Fig.10 , an exemplary method 1000 for cooling an electric machine will be described. The exemplary method 1000 may include operating an electric machine 100 at block 1002, the electric machine 100 including a plurality of operating elements 200 that generate heat. The electric machine 100 may include a stator housing 302 having a cooling structure 500, the cooling structure 500 defining a fluid domain 950 containing a working fluid 956. The cooling structure 500 may include a steam chamber 502. The exemplary method 1000 may include heating the working fluid 956 at block 1004 and flowing the working fluid 956 through the fluid domain 950. The fluid domain 950 may include a plurality of cooling conduits 802, such as a plurality of steam channels 506. The exemplary method 1000 may include transferring heat from the cooling structure 500 to a cooling fluid 114 at block 1006, the cooling fluid 114 flowing along one or more cooling surfaces 108 (such as one or more stator cooling surfaces 110 and / or one or more rotor cooling surfaces 112) contacting a surface of the electric machine 100 (such as a surface of the stator assembly 102 and / or a surface of the rotor 104). For example, the one or more cooling surfaces 108 (such as one or more stator cooling surfaces 110) may provide the cooling fluid 114 contacting a surface of the stator housing 302, such as a surface of the stator housing 302 including a plurality of cooling fins 314. The one or more cooling surfaces 108 may be disposed about a radially inward portion of the electric machine 100, such as, for example, Figure 1A and Figure 1B Additionally, or in the alternative, one or more cooling surfaces 108 may be disposed about a radially outer portion of the electric machine 100 .

[0094] The cooling structure 500 may include a vapor chamber 502. The exemplary method 1000 may include evaporating the working fluid 956 at one or more evaporator portions 508 of the cooling structure 500, such as at one or more evaporator portions 508 of the vapor chamber 502, at block 1008. At block 1010, the exemplary method 1000 may include condensing the working fluid 956 at one or more condenser portions 510 of the cooling structure 500, such as at one or more condenser portions 510 of the vapor chamber 502. When the working fluid 956 evaporates, the latent heat of evaporation absorbed by the working fluid cools the evaporator portion 508 of the cooling structure. The evaporated working fluid 956 increases the vapor pressure, which drives mass transfer from the evaporator portion 508 of the vapor chamber 502 to the condenser portion 510 of the vapor chamber 502. As the working fluid 956 condenses, latent heat is released from the working fluid 956 , and in some embodiments, one or more evaporator portions 508 and / or one or more condenser portions 510 may be variably located within the vapor chamber 502 , for example based at least in part on a temperature and / or temperature gradient of the cooling structure 500 .

[0095] Further aspects of the invention are provided by the subject matter of the following clauses:

[0096] 1. An electric machine, comprising: a stator assembly including a stator housing; and one or more rotors coupled to the stator by a rotor shaft assembly; wherein the stator housing includes a cooling structure, the cooling structure including a plurality of cooling body portions and a plurality of cooling ducts defined by the plurality of cooling body portions.

[0097] 2. An electric machine according to any clause herein, wherein the stator housing comprises a winding ring defining a plurality of winding slots respectively configured to receive electromagnetic elements, and a cooling structure disposed within at least a portion of the winding ring.

[0098] 3. An electric machine according to any clause herein, wherein the stator housing comprises: a winding annulus defining a plurality of winding slots respectively configured to receive electromagnetic elements, and at least a portion of the cooling structure disposed within at least a portion of the winding annulus.

[0099] 4. An electric machine according to any clause herein, wherein the stator housing comprises: a plurality of cooling fins, and at least a portion of the cooling structure is disposed within at least a portion of the plurality of cooling fins.

[0100] 5. An electric machine according to any clause herein, wherein the cooling structure comprises: a vapor chamber comprising an internal wicking structure and one or more vapor channels.

[0101] 6. An electric machine according to any clause herein, wherein the cooling structure comprises: one or more evaporator sections and one or more condenser sections.

[0102] 7. An electric motor according to any of the clauses herein, wherein the winding annulus comprises: an inner annular portion, an outer annular portion, and a plurality of winding flanges arranged between the inner annular portion and the outer annular portion; and wherein the cooling structure comprises: one or more evaporator portions and one or more condenser portions, wherein the one or more evaporator portions are arranged around the plurality of winding flanges, and wherein the one or more condenser portions are arranged around the inner annular portion and / or the outer annular portion.

[0103] 8. An electric machine according to any of the clauses herein, wherein the winding ring includes a plurality of cooling fins, and wherein the cooling structure includes: one or more evaporator sections arranged around a location of the cooling structure that is relatively far from the plurality of cooling fins; and one or more condenser sections arranged around a location of the cooling structure that is relatively near the plurality of cooling fins.

[0104] 9. An electric machine according to any clause herein, wherein the plurality of cooling fins define at least part of the one or more condenser portions of the cooling structure.

[0105] 10. An electric machine according to any of the clauses herein, wherein the cooling structure comprises: one or more evaporator sections and one or more condenser sections, wherein the one or more evaporator sections and / or the one or more condenser sections have a variable location, the variable location being at least partially dependent on one or more temperature gradients of the cooling structure that may exist during operation of the electric machine.

[0106] 11. An electric machine according to any clause herein, wherein the cooling structure defines a flow path configured to allow a working fluid to flow from an inlet to an outlet.

[0107] 12. An electric machine according to any clause herein, wherein the cooling structure comprises a lattice structure, a mesh structure, a wicking structure, and / or an agglomerated structure.

[0108] 13. An electric machine according to any clause herein, wherein the cooling structure comprises an agglomerated structure comprising sintered powder material and / or partially melted powder material from an additive manufacturing process used to form the stator housing.

[0109] 14. An electric machine as described in any clause herein, wherein the cooling structure comprises a vapor chamber comprising a wicking structure and one or more vapor channels.

[0110] 15. An electric machine according to any clause herein, wherein the cooling structure comprises a three-dimensional array of cooling body portions and cooling duct portions interspersed with one another.

[0111] 16. An electric machine according to any clause herein, wherein the cooling structure comprises a random or semi-random configuration of lattices, meshes, wicking and / or agglomerated structures.

[0112] 17. An electric machine according to any clause herein, wherein the stator housing comprises a single integrated component formed by an additive manufacturing process.

[0113] 18. A method of forming a stator housing for an electric machine, the method comprising: additively manufacturing a stator housing including a cooling structure, the cooling structure defining a fluid domain; coupling a heat transfer fluid source to the stator housing and introducing a working fluid into the fluid domain defined by the cooling structure; and sealing the cooling structure with respect to the working fluid contained within the fluid domain of the cooling structure.

[0114] 19. A method according to any clause herein, wherein the stator housing comprises a winding ring and a cooling structure, the winding ring defining a plurality of winding slots respectively configured to receive electromagnetic elements, the cooling structure being disposed within at least a portion of the winding ring, wherein the cooling structure comprises a plurality of cooling body portions and a plurality of cooling ducts defined by the plurality of cooling body portions.

[0115] 20. An electric machine according to any clause herein, wherein the stator housing comprises a single integrated component.

[0116] 21. A method according to any clause herein, comprising: heating the working fluid and purging non-condensable gases from the fluid domain; and sealing the cooling structure with respect to the working fluid in a heated state.

[0117] 22. A method according to any clause herein, wherein the electric machine is constructed according to any clause herein.

[0118] 23. A method for cooling an electric machine, the method comprising: operating an electric machine comprising a plurality of operating elements that generate heat, the electric machine comprising a stator housing having a cooling structure, the cooling structure defining a fluid domain containing a working fluid; heating the working fluid in the fluid domain and causing the working fluid to flow through the fluid domain; and transferring heat from the cooling structure to a cooling fluid that flows along one or more cooling surfaces contacting a surface of the electric machine.

[0119] 24. A method according to any of the clauses herein, wherein the electric machine includes a stator assembly, one or more rotors, a rotor shaft assembly coupling the one or more rotors to the stator assembly, and a plurality of operating elements including a plurality of electromagnetic elements, wherein the stator assembly includes a stator housing, the stator housing includes a winding ring defining a plurality of winding slots respectively accommodating corresponding electromagnetic elements of the plurality of electromagnetic elements, and a cooling structure disposed within at least a portion of the winding ring, wherein the cooling structure includes a plurality of cooling body portions and a plurality of cooling ducts defined by the plurality of cooling body portions, wherein the plurality of cooling ducts define a fluid domain containing a working fluid, and wherein operating the electric machine includes the plurality of operating elements generating heat.

[0120] 25. A method according to any clause herein, comprising heating the working fluid in the fluid domain by generating heat at least in part by the plurality of operating elements, and flowing the working fluid through the fluid domain.

[0121] 26. A method according to any clause herein, comprising: evaporating a working fluid at one or more evaporator portions of the cooling structure; and condensing the working fluid at one or more condenser portions of the cooling structure.

[0122] 22. A method according to any clause herein, wherein the electric machine is constructed according to any clause herein.

[0123] This written description uses exemplary embodiments to describe the presently disclosed subject matter (including the best mode), and also to enable those skilled in the art to practice such subject matter (including making and using any devices or systems and performing any incorporated methods). The patentable scope of the presently disclosed subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ significantly from the literal language of the claims.

Claims

1. A motor, comprising: a stator assembly comprising a stator housing; and one or more rotors coupled to the stator by a rotor shaft assembly; wherein the stator housing comprises a winding ring and a cooling structure, the winding ring defining a plurality of winding slots respectively configured to receive electromagnetic elements, the cooling structure being disposed within at least a portion of the winding ring, wherein the cooling structure comprises a plurality of cooling body portions and a plurality of cooling ducts defined by the plurality of cooling body portions, wherein the plurality of cooling ducts define a fluid domain containing a working fluid, Wherein, the cooling structure includes one or more evaporator parts and one or more condenser parts, and the working fluid evaporates at the one or more evaporator parts and condenses at the one or more condenser parts.

2. The motor according to claim 1, wherein: The stator housing comprises: A plurality of cooling fins, and at least a portion of the cooling structure disposed within at least a portion of the plurality of cooling fins.

3. The motor according to claim 1, wherein: The cooling structure comprises: A vapor chamber includes an internal wicking structure and one or more vapor channels.

4. The motor according to claim 1, wherein: The winding annulus comprises: an inner annular portion, an outer annular portion, and a plurality of winding flanges disposed between the inner annular portion and the outer annular portion; and Wherein the one or more evaporator portions are disposed around the plurality of winding flanges, and wherein the one or more condenser portions are disposed around the inner annular portion and / or the outer annular portion.

5. The motor according to claim 1, wherein: The winding ring includes a plurality of cooling fins, and wherein the one or more evaporator portions are arranged around a location of the cooling structure that is relatively far from the plurality of cooling fins; and the one or more condenser portions are arranged around a location of the cooling structure that is relatively near the plurality of cooling fins.

6. The motor according to claim 5, wherein: The plurality of cooling fins define at least a portion of the one or more condenser portions of the cooling structure.

7. The motor according to claim 1, wherein: The one or more evaporator portions and / or the one or more condenser portions have a variable location that depends at least in part on one or more temperature gradients of the cooling structure that may exist during operation of the electric machine.

8. The motor according to claim 1, wherein: The cooling structure defines a flow path configured to allow a working fluid to flow from an inlet to an outlet.

9. The motor according to claim 1, wherein: The cooling structure includes a lattice structure, a mesh structure, a wicking structure, and / or an agglomerated structure.

10. The electric machine according to claim 1, wherein: The cooling structure comprises an agglomerated structure comprising sintered powder material and / or partially melted powder material from an additive manufacturing process used to form the stator housing.

11. The electric machine according to claim 1, wherein: The cooling structure includes a vapor chamber including a wicking structure and one or more vapor channels.

12. The electric machine according to claim 1, wherein: The cooling structure includes a three-dimensional array of cooling body portions and cooling conduit portions interspersed with one another.

13. The electric machine according to claim 1, wherein: The cooling structures include random or semi-random configurations of lattices, meshes, wicking and / or agglomerated structures.

14. The electric machine according to claim 1, wherein: The stator housing comprises a single integrated component formed by an additive manufacturing process.

15. A method of forming a stator housing for an electric machine, the method comprising: additively manufacturing a stator housing including a cooling structure, the cooling structure defining a fluid domain; coupling a source of working fluid to the stator housing and introducing the working fluid into the fluid domain defined by the cooling structure; as well as sealing the cooling structure with the working fluid contained within the fluid domain of the cooling structure; The stator housing includes a winding ring and a cooling structure, the winding ring defines a plurality of winding slots respectively configured to receive electromagnetic elements, the cooling structure is arranged in at least a portion of the winding ring, wherein the cooling structure includes a plurality of cooling body parts and a plurality of cooling ducts defined by the plurality of cooling body parts, wherein the cooling structure includes one or more evaporator parts and one or more condenser parts, and the working fluid evaporates at the one or more evaporator parts and condenses at the one or more condenser parts.

16. The method according to claim 15, wherein: The stator housing comprises a single integrated component.

17. The method according to claim 15, comprising: heating the working fluid and removing non-condensable gases from the fluid domain; as well as The cooling structure is sealed while the working fluid is in a heated state.

18. A method for cooling an electric machine, the method comprising: operating an electric machine, the electric machine comprising a stator assembly, one or more rotors, a rotor shaft assembly coupling the one or more rotors to the stator assembly, and a plurality of operating elements comprising a plurality of electromagnetic elements, wherein the stator assembly comprises a stator housing, the stator housing comprising a winding annulus and a cooling structure, the winding annulus defining a plurality of winding slots respectively receiving corresponding electromagnetic elements of the plurality of electromagnetic elements, the cooling structure being disposed within at least a portion of the winding annulus, wherein the cooling structure comprises a plurality of cooling body portions and a plurality of cooling conduits defined by the plurality of cooling body portions, wherein the plurality of cooling conduits define a fluid domain containing a working fluid, and wherein operating the electric machine comprises the plurality of operating elements generating heat; generating heat at least in part by the plurality of operative elements to heat the working fluid in the fluid domain and flowing the working fluid through the fluid domain; as well as transferring heat from the cooling structure to a cooling fluid that flows along one or more cooling surfaces and contacts a surface of the electric machine, wherein the method comprises evaporating a working fluid at one or more evaporator portions of the cooling structure; and condensing a working fluid at one or more condenser portions of the cooling structure.

Images