ENVIRONMENT

BACKGROUND

[0001] The constraints of a transportation system that seeks to promote high speed, high efficiency, and high power density, impose challenges that are not present in the state of the art. In particular, such a transportation system may include electromagnetic machines and/or electromagnetic actuators moving in a low-pressure environment, which may experience significant heat and a corona which erodes surfaces of the electromagnetic machine.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0002] For a better understanding of the various examples described herein and to show more clearly how they may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which: [0003] FIG. 1A depicts a perspective view of a device that includes encapsulation and shielding for a low pressure environment, according to non-limiting examples.

[0004] FIG. IB depicts a perspective view of one electromagnetic component of the device of FIG. 1A, according to non-limiting examples.

[0005] FIG. 2 depicts a cross-section of the electromagnetic component of FIG. IB through the line A- A, according to non-limiting examples.

[0006] FIG. 3 depicts a method of encapsulation and shielding for a low pressure environment, according to non-limiting examples.

[0007] FIG. 4 depicts a method of applying a thermally conductive flexible material to an electromagnetic component, according to non-limiting examples. [0008] FIG. 5 depicts a method of applying an electrically conductive flexible material to an electromagnetic component and, in particular, to a thermally conductive flexible material on the electromagnetic component, according to non-limiting examples.

DETAILED DESCRIPTION

[0009] The constraints of a transportation system that seeks to promote high speed, high efficiency, and high power density, impose challenges that are not present in the state of the art. In particular, such a transportation system may include electromagnetic machines and/or electromagnetic actuators moving in a low-pressure environment, which may experience significant heat and a corona (e.g. an electrical corona) which erodes surfaces of the electromagnetic machine. Electromagnetic components of the electromagnetic machine may be most vulnerable to such heat and/or such a corona. For example, as understood herein, a low-pressure environment may be understood to include any suitable environment having a pressure that is lower than atmospheric pressure including, but not limited to, a pressure range of about 10 Pa to about 100 Pa.

[0010] In particular, electrical windings around pole portions of an electromagnetic machine and/or electromagnetic actuator (referred to interchangeably hereafter as an electromagnetic machine) may be particularly vulnerable to heat and/or corona effects in a low-pressure environment.

[0011] For example, significant heat may be generated at the electrical windings which may degrade the electrical windings. The heat is generally challenging to dissipate as the electromagnetic machine generally moves in the low-pressure environment, and hence heat dissipation in the low-pressure environment may be significantly reduced compared to heat dissipation at atmospheric pressure (e.g. due to reduced convection in the low-pressure environment as compared to, for example, an atmospheric pressure environment).

[0012] Furthermore, a corona is generally ionization of air that results in electron bombardment of surfaces, and hence leads to erosion thereof. As electrical windings may generally be the least robust component of the electromagnetic machine, they may be particularly sensitive to corona effects and/or erosion.

[0013] In particular, surfaces of an electromagnetic machine for a low-pressure environment should be at a ground potential to prevent corona. Furthermore, for many electromagnetic machines (e.g. especially those lacking a thermal management system, such as cold plates, and the like), the surfaces should dissipate heat as quickly as possible. However, providing these features in combination can be particularly challenging for electrical windings in a low-pressure environment. [0014] Exacerbating the problem, certain electromagnetic components may have dimensions and coefficients of thermal expansion where thermal expansion and contraction can place a large amount of physical stress on the electromagnetic components. For example, physical stresses due to thermal expansion and contraction can cause delamination of coatings on electromagnetic components; when such coating are conductive and are to reduce and/or prevent a corona, as described below, a risk of electrical failure of the electromagnetic components may occur due to creepage. Hence, any coatings used with electromagnetic components described herein are selected to have a have a bonding strength which may withstand thermal expansion and contraction of the electromagnetic components described herein, which may reduce this risk.

[0015] Hence, provided herein is an electromagnetic machine that includes electromagnetic components, including, but not limited to, an electromagnetic winding. At least a portion of the electromagnetic components are first coated with a thermally conductive flexible material, that may be silicone-based, with a thermal conductivity selected to conduct heat away from the electromagnetic components in operation, for example in a low pressure environment. In a particular example, the thermal conductivity may be one or more of at least about 0.5 W/(m-K) (e.g. watts per meter-kelvin) and/or about 0.65 W/(m-K) and/or about 1 W/(m-K). However, any suitable thermal conductivity is within the scope of the present specification.

[0016] An electrically conductive flexible material is then disposed on the thermally conductive flexible material, the electrically conductive flexible material having an electrical sheet resistance selected to reduce and/or prevent corona formation at the electromagnetic components in operation, for example in a low pressure environment. Indeed, in particular, the electrical sheet resistance of the electrically conductive flexible material may be specifically selected to prevent corona formation at the electromagnetic components in operation, for example in the low pressure environment. In a particular example, the electrical sheet resistance of the electrically conductive flexible material may be between about 1 ohms/square and less than about 1000 ohms/square, for example at temperatures between about -40°C and about 150°C. However, any suitable electrical sheet resistance at any suitable temperatures is within the scope of the present specification Furthermore, the electrically conductive flexible material and the thermally conductive flexible material provided herein may be selected to have respective moduli of elasticity of about 10 MPa and bond strength of a same and/or similar order of magnitude (e. g. the electrically conductive flexible material and the thermally conductive flexible material provided herein may be selected to have respective bond strengths of about 10 MPa). However, any suitable modulus of elasticity and/or any suitable bond strength are within the scope of the present specification.

[0017] As such, the electrically conductive flexible material is at an outside and/or external surface of the electromagnetic machine (e.g. where the electromagnetic components are located) and may be grounded to prevent (and/or reduce) corona effects at the external surface of the electromagnetic machine where the electromagnetic components are located. Furthermore, the thermally conductive flexible material may generally conduct heat away from the electromagnetic components to the electrically conductive flexible material at the external surface of the electromagnetic components, where the heat may be dissipated. However, alternatively, the electromagnetic machine provided herein may include a thermal management system, and/or an external and/or an internal heat sink, such as cold plates, and the like, and heat may be dissipated via such a thermal management system, in these examples, the thermally conductive flexible material may assist in transferring heat to such a thermal management system and/or heat sink and/or cold plate.

[0018] Hence, when the electromagnetic machine, and in particular the electromagnetic components are in operation in a low pressure environment, the thermally conductive flexible material may conduct heat away from the electromagnetic components for dissipation at the surface of the electromagnetic components, and the electrically conductive flexible material at the surface may be grounded to prevent (and/or reduce a likelihood of) a corona from forming the surface. As mentioned previously, alternatively, thermally conductive flexible material may assist in transferring heat to such a thermal management system and/or heat sink and/or cold plate.

[0019] Furthermore, as the thermally conductive flexible and the electrically conductive flexible material are flexible, they are generally suited to the thermal expansion and contraction of the electromagnetic components. As mentioned above, the electrically conductive flexible material and the thermally conductive flexible material provided herein may be selected to have respective moduli of elasticity and respective bond strengths of about 10 MPa and/or any suitable values. In particular term “flexible material” as used herein may be understood, in some examples, to include materials which generally elastically deform under stress, such as stress applied due to thermal expansion of components on which the flexible material is located, and which may return to an initial shape when such stress is removed. As such, a flexible material as provided herein is understood to be deformable without losing physical integrity and/or is pliable, and the like. In some examples, a “flexible material” may interchangeably be referred to herein as a “ductile material”; in more specific examples, a “flexible material” and/or “ductile material” may comprise an “elastomeric material”, and the like.

[0020] As provided herein, the thermally conductive flexible material may be applied by placing the electromagnetic components (and/or an entirety of the electromagnetic machine (e.g. as uncoated) in a mold, and filling the mold with one or more curable raw materials which, when cured, form the thermally conductive flexible material. A vacuum may be applied to mold to remove air bubbles from the one or more curable raw materials (e.g. the mold containing the electromagnetic components and the one or more curable raw materials may be placed into a chamber that is evacuated). The mold, with the one or more curable raw materials coating the electromagnetic components therein, may be heated to a first given temperature to cure, and/or partially cure, the one or more curable raw materials into the thermally conductive flexible material. The electromagnetic components coated with the thermally conductive flexible material may be removed from the mold and heated to a second given temperature for stabilizing a respective raw material of the electrically conductive flexible material, the second given temperature higher than the first given temperature. The first given temperature may be selected to assist with removal of the thermally conductive flexible material and the electromagnetic components from the mold. And the second given temperature may be selected to stabilize and/or more fully cure the thermally conductive flexible material, and/or to place the thermally conductive flexible material into a state compatible with coating of raw materials of the electrically conductive flexible material. For example, raw materials of the electrically conductive flexible material may sprayed onto the thermally conductive flexible material after the thermally conductive flexible material is heated to the second given temperature (e.g. for a suitable time period) and, in some examples, if the thermally conductive flexible material were not heated to the second given temperature, solvents used rendering the electrically conductive flexible material sprayable may cause issues with the thermally conductive flexible material. Put another way, the thermally conductive flexible material may be heated to the second given temperature, prior to coating with the electrically conductive flexible material, to better cure and/or stabilize the thermally conductive flexible material prior to coating with the electrically conductive flexible material.

[0021] After the thermally conductive flexible material is applied to the electromagnetic components, and after the thermally conductive flexible material is stabilized at the second given temperature, one or more curable raw materials for the electrically conductive flexible material is applied to the thermally conductive flexible material. The one or more curable raw materials may be air-dried as coated on the thermally conductive flexible material. After the air-drying, the curable raw material may be heated, as coated on the thermally conductive flexible material and air-dried, to a third given temperature, for a suitable time period, to cure the curable raw material into the electrically conductive flexible material; the third given temperature may be the same as the second given temperature, or the third given temperature may be different from the second given temperature; in some particular examples, the third given temperature may be greater than or about equal to the third given temperature and/or within about 10% of the second given temperature. The third given temperature and/or the cure process for the electrically conductive flexible material may also result in cross-linking between the thermally conductive flexible material and the electrically conductive flexible material; for example, when the thermally conductive flexible material and the electrically conductive flexible material have a same backbone material, such as silicone, the silicones may bond to each other, which may provide additional stability between the thermally conductive flexible material and the electrically conductive flexible material, though the silicones used for the materials may be of different types.

[0022] A first aspect of the present specification provides an electromagnetic machine comprising: an electromagnetic component; a thermally conductive flexible material disposed on at least a portion of the electromagnetic component, the thermally conductive flexible material having a thermal conductivity selected to conduct heat away from the electromagnetic component in operation; and an electrically conductive flexible material disposed on the thermally conductive flexible material, the electrically conductive flexible material having an electrical sheet resistance selected to one or more of reduce and prevent corona formation at the electromagnetic component in operation.

[0023] A second aspect of the present specification provides a method comprising: coating at least a portion of electromagnetic component with a thermally conductive flexible material, the thermally conductive flexible material having a thermal conductivity selected to conduct heat away from the electromagnetic component when the electromagnetic component is in operation; and, thereafter, coating the thermally conductive flexible material with an electrically conductive flexible material, the electrically conductive flexible material having an electrical sheet resistance selected to one or more of reduce and prevent corona formation at the electromagnetic component in operation [0024] Attention is next directed to FIG. 1A which depicts a perspective view of an electromagnetic machine 100 in a partially disassembled state, which includes an electromagnetic component 102 provided in the form of an electrical winding. FIG. IB shows a perspective view of the electromagnetic component 102 as disassembled from the remainder of the electromagnetic machine 100.

[0025] An electromagnetic machine which incorporates the electromagnetic component 102 may be attached to a pod and/or vehicle and/or payload used in a high speed transport system which may be deployed on land, underground, overland, overwater, underwater, and the like; a pod and/or vehicle and/or payload of the highspeed transport system may comprise a vehicle, and the like, for transporting cargo and/or passengers, and the like, and/or any other suitable payloads. In general, the electromagnetic component 102 provided in the form of an electrical winding may be replaceable at the electromagnetic machine 100 and may, for example, be placed on a pole portions (e.g. a pole portion 103 described in more detail below) of the electromagnetic machine 100, and removed/replaced when damaged, and the like.

[0026] As depicted, the electromagnetic component 102 has a length longer than a width, and hence is arranged along a longitudinal axis 104 and further forms an aperture 106. While not depicted in FIG. 1 A or FIG. IB (e.g. however, see FIG. 2), the electromagnetic component 102 may include an electrical coil around therein, for example via a wire repeatedly wrapped around the aperture 106; as best seen in FIG. IB, opposite ends 107 of such a wire are depicted at an end of the electromagnetic component 102 along the longitudinal axis 104.

[0027] The opposite ends 107 are understood to be electrically connected to electrical connectors 108, as supported by a faceplate 110 and/or frame at an end of the electromagnetic component 102 along the longitudinal axis 104 (e.g. the end of the electromagnetic component 102 along the longitudinal axis 104 where the opposite ends

107 are located), though the opposite ends 107 and the electrical connectors 108, etc., may be in any suitable position.

[0028] The electrical connectors 108 generally include portions (e.g. ports and the like) which receive and/or convey power from a power source via complementary plugs and/or connectors of the power source, and grounding portions which may be connected to grounding portions of the power source (e.g. grounding portions of the plugs and/or connectors of the power source). As depicted, the grounding portions of the electrical connectors 108 are threaded such that the electrical connectors 108 may be mated to grounding portions of plugs and/or connectors of the power source that have complementary threads, though any suitable devices for mating the electrical connectors

108 an external power source is within the scope of the present specification. The power source may be at a pod to which the electromagnetic machine 100 is attached.

[0029] As depicted, electrical connections between the electrical connectors 108 and the opposite ends 107 of the wire that form the coil of the electromagnetic component 102 may be located in a housing 112 (e.g. an insulating encapsulating housing, which, as described in more detail below, may be formed from a thermally conductive flexible material used to coat the remainder of the electrical component 102) which may be coated with an electrically conductive material, such as an electrically conductive flexible material used to coat the remainder of the electrical component 102. The faceplate 110 may be conducting, and electrically connected to the electrically conductive material coating the housing 112.

[0030] As will be explained with respect to FIG. 2, the electromagnetic component 102 includes an electrically conductive flexible material at an external surface thereof which is also electrically connected to the housing 112 and/or also coats the housing 112. [0031] For example, the electrically conductive material coating the housing 112 may comprise an electrically conductive paint which coats the housing 112 and furthermore may be applied after the housing 112 is attached to the electromagnetic component 102, and which is also partially applied to the electrically conductive flexible material at the external surface of the electromagnetic component 102. However, the housing 112 may be formed from the thermally conductive flexible material used to coat the remainder of the electrical component 102 and coated with the electrically conductive flexible material used to coat the remainder of the electrical component 102.

[0032] Hence, external surfaces of the electromagnetic component 102, the housing 112 and the faceplate 110 may all be electrically connected, and may be grounded via a grounding portion the electrical connectors 108 as described above.

[0033] While not depicted, a stress grading paint, and the like, may extend from a conductive external surface of the electromagnetic component 102 under the housing 112 and which is also electrically connected to the electrically conductive material coating the housing 112, to provide a pathway for electrical fields (e.g. formed at the conductive external surface of the electromagnetic component 102 and the electrically conductive material coating the housing 112) to “gracefully” fall off and/or decline.

[0034] For completeness, also depicted in FIG. 1A are a pole portion 103 attached to a backplane 114 of the electromagnetic machine 100, as disassembled from the electromagnetic component 102. However, the electromagnetic machine 100 may be assembled such that the pole portion 103 is inserted through the aperture 106 and the electromagnetic machine 100 may rest on the backplane 114. While not depicted, the electromagnetic machine 100 may include attachment devices, such as straps, and the like, for attaching the electromagnetic machine 100 to the pole portion 103 and/or the backplane 114. The pole portion 103 and the backplane 114 are understood to comprise any suitable combination of magnetically conducting materials.

[0035] As such, it is understood that the pole portion 103 and the backplane 114 may be of complementary shapes and/or sizes, and the like. The electromagnetic machine 100 may include other components such as one or more cold plates, and the like, to assist in cooling the electromagnetic machine 100, as well as other electromagnetic components, pole portions and backplanes, which may be joined together and attached to a pod. [0036] In operation, a current may be provided to the electrical coil in the electromagnetic component 102 via the electrical connectors 108 such that a magnetic field is formed in the aperture 106 at the pole portion 103, which may interact with a track (not depicted) and the like, to perform functionality related to moving a pod to which the electromagnetic machine 100 is attached, including, but not limited to, propelling, braking, levitating, and/or stabilizing the pod, and the like. As such, the pole portion 103 and the backplane 114 are understood to comprise any suitable magnetically conducting material and/or materials.

[0037] While a particular example of the electromagnetic machine 100 is depicted, with a particular shape, size and configuration, electromagnetic machine 100 may be of any suitable shape, size and/or configuration. For example, while the electromagnetic component 102 is depicted as planar and arranged along the longitudinal axis 104, the electromagnetic component 102 may have steps and or kinks, and/or have any suitable shape which may be arranged along the longitudinal axis 104 or not arranged along the longitudinal axis 104. Furthermore, the electromagnetic component 102 may be removable and/or replaceable at the electromagnetic machine 100; for example, as depicted, the electromagnetic component 102 may be removed from the pole portion 103 and replaced with another, similar electromagnetic component.

[0038] As mentioned above, when the electromagnetic machine 100 is in operation in a low-pressure environment, the electromagnetic components 102 may generate heat, and, furthermore, there is a risk that a corona may develop at an external surface and/or portion and/or face of the electromagnetic machine 100, which may be mitigated by grounding the electrically connected external surfaces of the electromagnetic component 102, the housing 112 and the faceplate 110. As such, the external surfaces of the electromagnetic component 102 are understood to be electrically conductive and furthermore the electromagnetic component 102 is adapted to conduct heat away from the electrical coil therein, as described hereafter.

[0039] For example, attention is next directed to FIG. 2 which depicts a cross-section through the line A-A of FIG IB through the electromagnetic component 102.

[0040] As depicted, the electromagnetic component 102 includes a wire 200 of an electrical coil therein, depicted in cross-section as circles; while only one circle of the wire 200 is indicated, it is understood that the wire 200 may be wound about the aperture 106 any suitable number of times, and each instance of a circle in FIG. 2 indicates a particular portion of the wire 200. Furthermore, while the wire 200 is shown in an ordered pattern (e.g. the circles of the wire 200 are arranged in an ordered grid), the wire 200 may be wound in any suitable pattern. It is further understood that, as depicted, the cross-section of the wire 200 may not be to scale. It is furthermore understood that the opposite ends 107 depicted in FIG. IB are opposite ends 107 of the wire 200. The wire 200 is furthermore understood to be insulated so that the wire 200 does not short to itself within the electromagnetic component 102.

[0041] Furthermore, as depicted, a surface 202 of the electromagnetic component 102, within which the wire 200 is located, may comprise an electrically insulating material 204. The electrically insulating material 204 may include, but is not limited to, electrically insulating tape applied to the surface 202 of electromagnetic component 102 using vacuum pressure impregnation; any suitable resin 206, and the like, may also be applied using the vacuum pressure impregnation which, as depicted, may at least partially surround the wire 200 within the surface 202.

[0042] Hence, as depicted, a portion of the electromagnetic component 102, within which the wire 200 is located may have a surface 202 which is coated with an electrically insulating material. However, in other examples, portions of the wire 200 may not be coated and/or may be exposed at the surface 202 (though the wire 200 is understood to be insulated from itself).

[0043] Regardless, the electromagnetic machine 100 further comprises a thermally conductive flexible material 208 disposed on at least a portion of the electromagnetic component 102, the thermally conductive flexible material 208 having a thermal conductivity selected to conduct heat away from the electromagnetic component 102 in operation.

[0044] As depicted, the thermally conductive flexible material 208 is disposed on the electrically insulating material 204, such as the electrically insulating tape, of the electromagnetic component 102 (e.g. the thermally conductive flexible material 208 is disposed on the surface 202). [0045] Regardless, the electromagnetic machine 100 further comprises an electrically conductive flexible material 210 disposed on the thermally conductive flexible material 208, the electrically conductive flexible material 210 having an electrical sheet resistance selected to reduce corona formation at the electromagnetic component 102 in operation, as described above. In particular, the electrically conductive flexible material 210 may be electrically connected to an electrically conductive coating of the housing 112 and the faceplate 110, and/or the electrically conductive flexible material 210 may also coat the housing 112 and be electrically connected to the faceplate 110; grounding portions of the electrical connectors 108 are also electrically connected to the faceplate 110 which is electrically connected to the remainder of electrical coatings of surfaces of the electrical component 102, all of which may be grounded via the grounding portions of the electrical connectors 108 (e.g. such a grounding portion may comprise a shell, and the like, of the electrical connectors 108 which provides an electrical path to a ground of the electromagnetic machine 100 and/or a pod and/or vehicle and/or payload to which the electromagnetic machine 100 is attached).

[0046] Details of the materials 208, 210 will next be described.

[0047] In particular, the thermally conductive flexible material 208 may comprise a silicone-based material having a thermally conductive filler material comprising a plurality of types of alumina including spherical alumina.

[0048] Furthermore, the thermally conductive filler material is understood to include other alumina types (e.g. other than spherical alumina), and content of the spherical alumina, relative to the other alumina types, may be selected to obtain a given viscosity of one or more curable raw materials of the thermally conductive flexible material 208, as well as a given thermal conductivity. Such one or more curable raw materials may include the silicone-based material in a form compatible with applying the thermally conductive flexible material 208 to the electromagnetic component 102 using a mold, as described below with respect to FIG. 3 and FIG. 4.

[0049] In particular, a content of the spherical alumina, relative to the other alumina types, maybe selected to achieve a thermal conductivity of the thermally conductive flexible material 208 of one or more of at least about 0.5 W/(m-K) and/or about 0.65 W/(m-K) and/or about 1 W/(m-K). In particular, a thermal conductivity of one or more of at least 0.65 W/(m-K) has been determined to assist with conducting heat away from the electromagnetic component 102, and in particular the wires 200, when the electromagnetic component 102 is in operation. Hence, a content of the thermally conductive filler material in the silicone-based material of the thermally conductive flexible material 208, may be selected to achieve such a thermal conductivity.

[0050] Furthermore, the thermally conductive flexible material 208 is understood to be provided as the one or more curable raw materials prior to being applied to the electromagnetic component, and a viscosity of the one or more curable raw materials (e.g. the silicone-based material) may be in a range of about 40,000 centipoise to about 15,000 centipoise (e.g. at respective speeds between about lrpm (revolutions per minute) and about lOrpm, as centipoise is generally measured with a viscometer that rotates a liquid to measure viscosity), with the content of the spherical alumina, relative to the other alumina types selected accordingly. Such a viscosity has been found to be compatible with a mold- based process for applying the thermally conductive flexible material 208 to the electromagnetic component 102, described in more detail below with respect to FIG. 3 and FIG. 4. However, any suitable viscosity is within the scope of the present specification. [0051] Hence, the content of the spherical alumina, relative to the other alumina types may be selected both to achieve a thermal conductivity of the thermally conductive flexible material 208 of at least 0.65 W/(m-K) and a viscosity of the one or more curable raw materials thereof in a range of about 15,000 centipoise to about 40,000 centipoise (e.g. at speeds between about lrpm and about lOrpm).

[0052] Furthermore, it is understood that the thermally conductive flexible material 208 may not be electrically conductive, and hence may act as an electrically insulating layer between electrically conductive flexible material 210 and the remainder of the electromagnetic component 102.

[0053] In some examples, the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may have a same “backbone” material, which may be understood to be a material to which filler materials may be added to achieve particular physical properties (e.g. particular viscosities and/or thermal conductivities and/or sheet resistances, and the like). [0054] For example, the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may each use silicone as a “backbone” material, but which include different filler materials, such as at least one suitable thermally conductive filler material (e.g. the alumina) for the thermally conductive flexible material 208 and at least one suitable electrically conducting and/or conductive filler material for the electrically conductive flexible material 210, described in more detail below.

[0055] As has also been described herein, selecting the materials 208, 210 to have respective moduli of elasticity and respective bond strengths of about 10 MPa (e.g. once cured) and which may be achieved using materials that have silicone as a “backbone” material, may also mitigate the physical stress caused by thermal expansion and contraction of the electromagnetic machine 100 and/or the electromagnetic component 102.

[0056] However, while the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may have a same backbone material, such as silicone, the backbone materials may not be identical; for example, while each of the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may each use a silicone as a respective backbone material, the silicones may be of different types, selected, for example, to be compatible with respective application processes of the thermally conductive flexible material 208 and the electrically conductive flexible material 210, described in more detail below. However, in general, whether a same or different backbone material, the materials 208, 210 may be selected have respective moduli of elasticity and respective bond strengths of about 10 MPa.

[0057] In particular, the electrically conductive flexible material 210 may be provided as one or more of a sprayable and solvenated curable raw material prior to being applied to the thermally conductive flexible material 208. Hence, as the two processes used to apply the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may be different (e.g. a mold-based process and a spray process), the silicones used in each may be different.

[0058] In some examples, the electrically conductive flexible material 210 may comprise a silicone-based material having an electrically conducting and/or conductive filler material comprising one or more of carbon nanotubes and silver particles, for example to achieve a sheet resistance of between about 1 ohms/square and less than about 1000 ohms/square, between about -40°C and about 150°C. Hence, a curable raw material of the electrically conductive flexible material 210 may include the silicone-based material in a form compatible with applying the electrically conductive flexible material 210 to the thermally conductive flexible material 208 using a spray technique, as described below with respect to FIG. 3 and FIG. 5.

[0059] In particular, sheet resistances in a range of between about 1 ohms/square and less than about 1000 ohms/square have been determined to reduce corona formation at the electromagnetic component 102 in operation, as described above. Furthermore, the electromagnetic component 102 may experience temperatures between about -40°C and about 150°C. Hence, a content of the electrically conducting and/or conductive filler material in the silicone-based material, may be selected to achieve such sheet resistances in such a temperature range. For example, the electrically conducting and/or conductive filler material may be provided only as carbon nanotubes, or only as silver particles, or only as other suitable conducting and/or conductive particles, or as a combination of carbon nanotubes and/or silver particles and/or other suitable conducting and/or conductive particles, with a content and/or ratios of such particles selected to achieve the a sheet resistance of between about 1 ohms/square and less than about 1000 ohms/square, between about -40°C and about 150°C.

[0060] Furthermore, as the electrically conductive flexible material 210 may be provided as one or more of a solvenated and sprayable curable raw material which is applied to the thermally conductive flexible material 208, a thickness of the electrically conductive flexible material 210 may be small and/or much thinner than the thermally conductive flexible material 208. As such, the electrically conductive flexible material 210 may not provide a significant thermal resistance, resulting in heat being easily conducted through the electrically conductive flexible material 210 to be dissipated in the low-temperature environment. However, the electrically conducting and/or conductive filler material of the electrically conductive flexible material 210 may have a thermal conductivity which assists in conduction of heat therethrough.

[0061] Furthermore, as the materials 208, 210 are each flexible, for example due to the use of silicone as backbone materials, the materials 208, 210 may physically stretch and contract with thermal expansion and contraction of the electromagnetic component 102 (e.g. along the longitudinal axis 104). Furthermore, the thermally conductive flexible material 208 is understood to conduct heat away from the wires 200 and/or the electromagnetic component 102 for dissipation at the electrically conductive flexible material 210 (e.g. and/or, alternatively, via a thermal management system, such as cold plates, and the like), and the electrically conductive flexible material 210 provides for reduction and/or prevention of a corona (e.g. when grounded). As such, in combination, the materials 208, 210 may address various thermal, physical and electrical problems of deploying an electromagnetic machine in a low-pressure environment. Hence, it is understood that the materials 208, 210 provide encapsulation and shielding (e.g. electrical shielding) for at least the electromagnetic component 102 of the electromagnetic machine 100.

[0062] While as depicted the materials 208, 210 coat the electromagnetic component 102 provided as electrical windings, in other examples, the materials 208, 210 may also coat the pole portion 103 and the backplane 114 and/or an entirety of the electromagnetic machine 100 other than the electrical connectors 108. In particular, the pole portion 103 and the backplane 114 may also be understood to comprise electromagnetic components of the electromagnetic machine 100. Hence, electromagnetic components (e.g. the electromagnetic component 102 connected to the pole portion 103 and the backplane 114) of the electromagnetic machine 100 may be coated with the materials 208, 210, but after assembly of the electromagnetic component 102 to the pole portion 103 and the backplane 114. However, as depicted in FIG. IB, the electrical connectors 108 and the faceplate 110 and may be attached to the electromagnetic component 102 prior to the coating of the materials 208, 210, though parts of the electrical connectors 108 that are to electrically connect to a power source may be masked during the coating. It is further understood that, when the thermally conductive flexible material 208 is applied to the pole portion 103 and/or the backplane 114, the thermally conductive flexible material 208 is applied to conductive and/or magnetically conducting surfaces; however, as the thermally conductive flexible material 208 is electrically insulating, there is generally little, to no, effect on formation of a magnetic field by the electromagnetic machine 100 in operation. As described below, the housing 112 may be formed from the thermally conductive flexible material 208 (e.g. when the thermally conductive flexible material 208 coats the remainder of the electromagnetic component 102), and the electrically conductive flexible material 210 may be applied to the housing 112 when applied to the remainder of the electromagnetic component 102. However, the housing 112 may alternatively be formed in any suitable manner and coated with the the materials 208, 210.

[0063] Put another way, the electromagnetic machine 100 may further comprise at a surface of an electromagnetic component of the electromagnetic machine 100 (e.g. the surface 202 the electromagnetic component 102 and/or a surface of the pole portion 103 and/or a surface of the backplane 114), one or more of: conductors (e.g. the pole portion 103 and/or the backplane 114) and an electrical insulating material (e.g. the electrically insulating material 204), and the thermally conductive flexible material 208 may be disposed on one or more of the conductors and the electrical insulating material at the surface.

[0064] Attention is next directed to FIG. 3 which depicts a block diagram of a process and/or method 300 of encapsulation and shielding for a low pressure environment. The method 300 will next be described with respect to the electromagnetic machine 100 and the materials 208, 210. However, the method 300 may be used to coat any suitable electromagnetic components using any suitable thermally conductive flexible material and any suitable electrically conductive flexible material. Variations of the method 300 are also within the scope of the present specification. Furthermore, in the following discussion, the electromagnetic component 102 may be provided as depicted in FIG. IB, with the connectors 108 and faceplate 110 attached prior to coating with the materials 208, 210 ; however, in other examples, electromagnetic component 102 may be provided without the connectors 108 and faceplate 110 attached prior to coating with the materials 208, 210. [0065] At a block 302, at least a portion of the electromagnetic component 102 is coated with the thermally conductive flexible material 208. As previously described, the thermally conductive flexible material 208 has a thermal conductivity selected to conduct heat away from the electromagnetic component 102 when the electromagnetic component is in operation.

[0066] At a block 304, which occurs after the at least a portion of the electromagnetic component 102 is coated with the thermally conductive flexible material 208, the thermally conductive flexible material is coated with the electrically conductive flexible material 210. As previously described, the electrically conductive flexible material 210 has an electrical sheet resistance selected to one or more of reduce and prevent corona formation at the electromagnetic component 102 in operation.

[0067] Particular examples of each of the block 302 and the block 304 are next respectively described in detail with regards to FIG. 4 and FIG. 5.

[0068] Attention is next directed to FIG. 4 which depicts a block diagram of a process and/or method 400 for applying a thermally conductive flexible material to an electromagnetic component. The block 302 of the method 300 may be implemented using the method 400, and/or any other suitable method. The method 400 will next be described with respect to the electromagnetic component 102 and the thermally conductive flexible material 208. However, the method 400 may be used to coat any suitable electromagnetic components using any suitable thermally conductive flexible material. Variations of the method 400 are also within the scope of the present specification.

[0069] Furthermore, the blocks of the method 400 may be implemented manually and/or automatically using robotic devices and the like.

[0070] At a block 402, the electromagnetic component 102 is placed into a mold (e.g. manually and/or using any suitable robotic devices, and the like). A portion of the electromagnetic component 102 may be masked, such as the portions of the connectors 108 that connect to an external power source (and/or, when the electromagnetic component 102 is provided without the connectors 108, the opposite ends 107 of the wire 200 may be masked), prior to placing the electromagnetic component 102 into the mold. However, in other examples, no masking may be used; rather, portions of the electromagnetic component 102 that are to electrically connect with external components may be coated with the thermally conductive flexible material 208 (and the electrically conductive flexible material 210) as described hereafter, and such material 208, 210 may be abraded and/or abraded, where suitable, after the coating processes. However, any suitable combination of techniques (and states of the electromagnetic component) for ensuring that suitable electrical components of the electromagnetic component 102 are electrically connected to one another are within the scope of the present specification.

[0071] In a particular example, however, the mold may be configured such that the connectors 108 and the faceplate 110 are excluded from the mold such that, as described below, when raw curable materials of the thermally conductive flexible material 208 are added to the mold, the connectors 108 and the faceplate 110 are not coated with such raw curable materials. In this particular example, the mold may also be shaped to form the housing 112 from the thermally conductive flexible material 208.

[0072] Such a mold may be of any suitable material, such a metal and/or a plastic, and may include a cavity whose surfaces define a shape of the thermally conductive flexible material 208 when applied to the electromagnetic component 102, and, for example, form the housing 112. Hence, the mold is understood to be of a size and shape which accommodates the electromagnetic component 102, as well as the thermally conductive flexible material 208. The cavity may also be coated with a mold release material prior to placing the electromagnetic component 102 therein.

[0073] It is furthermore understood that the electromagnetic component 102 may have been previously coated with electrically insulating tape (e.g. the electrically insulating material 204), and the like, applied to the electromagnetic component using vacuum pressure impregnation, but that the electromagnetic component 102, when placed in the mold, is not yet coated with the materials 208, 210. Hence, at this phase of the method 400, the surface 202 may be an external surface of the electromagnetic component 102.

[0074] At a block 404, the mold is filled with the thermally conductive flexible material 208 provided as one or more curable raw materials. For example, the one or more curable raw materials of the thermally conductive flexible material 208 may comprise uncured silicone in a liquid form with the thermally conductive filler materials, described herein, added to the uncured silicone. The viscosity of the thermally conductive flexible material 208 provided as one or more curable raw materials has been described herein and may assist with filling the cavity, as well as encapsulating and/or penetrating the electromagnetic component 102. As mentioned above, a viscosity of the one or more curable raw materials may be in a range of about 15,000 centipoise to about 40,000 centipoise at speeds between about lrpm and about lOrpm

[0075] At a block 406, a vacuum is applied to the mold with the one or more curable raw materials coating the electromagnetic component 102 therein. For example, the mold may be placed in a vacuum chamber and/or a thermal vacuum chamber (TVAC), and the vacuum chamber may be evacuated, which generally results in outgassing of the one or more curable raw materials, as well as encapsulation and/or penetration of the one or more curable raw materials at the surface 202 of the electromagnetic component 102.

[0076] Any suitable vacuum may be used, which may be lower than a pressure of the low- pressure environment in which the electromagnetic component 102 is later used. Furthermore, the vacuum may be held for any suitable time period which may be compatible with effective outgassing, etc., of the one or more curable raw materials, and may be in a range of an hour to ten hours and/or any other suitable time period.

[0077] At a block 408, the mold may be heated with the one or more curable raw materials, of the thermally conductive flexible material 208, coating the electromagnetic component 102 therein to a first given temperature to cure the one or more curable raw materials into the thermally conductive flexible material 208. In some examples, the mold may be heated in a TVAC where the mold is presently located, having undergone the vacuum described above with respect to the block 408; in such examples, heating the mold may occur with or without a vacuum applied. When the mold is heated with vacuum applied, the mold may include heating components disposed in or on the mold to heat the mold. When the mold is heated without a vacuum applied, the mold may be heated by heating an atmosphere around the mold. However, the mold may be heated external to a vacuum chamber, for example in a heating chamber.

[0078] Furthermore the first given temperature is selected to cure the one or more curable raw materials of the thermally conductive flexible material 208 into a flexible form and/or to ensure that the thermally conductive flexible material 208, coating the electromagnetic component 102, is removable from the mold. For example, the first given temperature may be a temperature compatible with curing liquid uncured silicone into a flexible form, but not so far as to bond with the mold. The first given temperature hence generally depends on the one or more curable raw materials but may be in a range of about 100°C to about 120°C for some liquid uncured silicone materials. Furthermore, the mold may be heated to the first given temperature for any suitable time period compatible with curing the one or more curable raw materials into a flexible form and may be in a range of an hour to ten hours and/or any other suitable time period.

[0079] When a TVAC is used, the TVAC may be programmed to apply a suitable vacuum and temperature sequence to apply the vacuum of the block 406 and the heat of the block 408. In general, once the heating to the first given temperature occurs for a suitable time period, the heat may be turned off to let the mold return to an ambient temperature.

[0080] At a block 410, after heating at the block 408, the thermally conductive flexible material 208 and the electromagnetic component 102 are removed from the mold. It is understood that the block 410 may include removing the mold from a TVAC and the like, prior to the removing the thermally conductive flexible material 208 and the electromagnetic component 102 from the mold.

[0081] At a block 412, the thermally conductive flexible material 208 and the electromagnetic component 102 are heated to a second given temperature for stabilizing the thermally conductive flexible material 208 electrically conductive flexible material (e.g. for a suitable time period), the second given temperature higher than the first given temperature. The second given temperature may be selected to stabilize and/or more fully cure the thermally conductive flexible material 208, and/or to place the thermally conductive flexible material 208 into a state compatible with coating of raw materials of the electrically conductive flexible material 210. In some examples, second given temperature may be about 150°C. For example, as described in more detail below, raw materials of the electrically conductive flexible material 210 may be sprayed onto the thermally conductive flexible material 208 after the thermally conductive flexible material 208 is heated to the second given temperature (e.g. for a suitable time period) and, in some examples, if the thermally conductive flexible material 208 were not heated to the second given temperature, solvents used to render the raw materials of the electrically conductive flexible material 210 may cause issues with the thermally conductive flexible material 208 when sprayed onto the thermally conductive flexible material 208. Put another way, the thermally conductive flexible material 208 may be heated to the second given temperature, prior to coating with the electrically conductive flexible material 210, to better cure and/or stabilize the thermally conductive flexible material 208 prior to coating with the electrically conductive flexible material 210.

[0082] In particular, as one or more curable raw materials of the electrically conductive flexible material 210 may be applied using a spray process, the one or more curable raw materials may be of a different type than that used with the thermally conductive flexible material 208 (e.g. different types of uncured silicones). Such one or more curable raw materials of the electrically conductive flexible material 210 may be more solvenated than the one or more curable raw materials used with the thermally conductive flexible material 208. Hence, the thermally conductive flexible material 208 may be heated to the second given temperature, prior to coating with the electrically conductive flexible material 210, electrically conductive flexible material to render the thermally conductive flexible material 208 resistant to being dissolved, and the like, by the solvents used with the one or more curable raw materials of the electrically conductive flexible material 210.

[0083] At this stage, the electrical component 102 and the thermally conductive flexible material 208 may have the form shown in FIG. 1A, with the housing 112 formed from the thermally conductive flexible material 208. Indeed, forming the housing 112 from the thermally conductive flexible material 208 assists with thermal conduction at the electrical component 102.

[0084] Attention is next directed to FIG. 5 which depicts a block diagram of a process and/or method 500 for applying a thermally conductive flexible material to an electromagnetic component and, in particular, to a thermally conductive flexible material on the electromagnetic component. The block 304 of the method 300 may be implemented using the method 500, and/or any other suitable method. The method 500 will next be described with respect to the electromagnetic component 102, and the thermally conductive flexible material 208 and the electrically conductive flexible material 210. However, the method 500 may be used to coat any suitable electromagnetic components using any suitable thermally conductive flexible material and/or electrically conductive flexible material. Variations of the method 500 are also within the scope of the present specification. [0085] Furthermore, the blocks of the method 500 may be implemented manually and/or automatically using robotic devices and the like.

[0086] It is further understood that the method 500 may occur after the method 400 has been used to coat the electromagnetic component 102, with the thermally conductive flexible material 208 and, for example, form the housing 112.

[0087] At a block 502, the thermally conductive flexible material 208 is coated with the electrically conductive flexible material 210 provided as one or more curable raw materials. For example, the one or more curable raw materials of the electrically conductive flexible material 210 may comprise uncured silicone in a sprayable, solvenated liquid form with the electrically conductive filler materials, described herein, added to the silicone.

[0088] Furthermore, the one or more curable raw materials of the electrically conductive flexible material 210 may be sprayed onto the electromagnetic component 102 where the thermally conductive flexible material 208 is located, for example using any suitable spray gun at any suitable spray speed, and/or using any suitable number of coats. In these examples, a solvent content of the one or more curable raw materials of the electrically conductive flexible material 210 may be selected for compatibility with a spray process. [0089] In other examples, the electromagnetic component 102 with the thermally conductive flexible material 208 applied, may be dipped into a container of the one or more curable raw materials of the electrically conductive flexible material 210, with a solvent content of the one or more curable raw materials of the electrically conductive flexible material 210 adapted accordingly.

[0090] Alternatively, the electromagnetic component 102 with the thermally conductive flexible material 208 applied, may be painted with the one or more curable raw materials of the electrically conductive flexible material 210, with a solvent content of the one or more curable raw materials of the electrically conductive flexible material 210 adapted accordingly.

[0091] Hence, coating the thermally conductive flexible material 208 with the electrically conductive flexible material 210 provided as one or more curable raw materials may comprise one or more of: spraying one or more curable raw materials onto the thermally conductive flexible material 208; painting the one or more curable raw materials onto the thermally conductive flexible material 208; and dipping the electromagnetic component 102 into the one or more curable raw materials.

[0092] As in some examples the housing 112 is formed from the thermally conductive flexible material 208, coating the thermally conductive flexible material 208 with the electrically conductive flexible material 210 provided as one or more curable raw materials may also include coating the housing 112 with the electrically conductive flexible material 210 provided as one or more curable raw materials; in these examples, the or more curable raw materials of the electrically conductive flexible material 210 are coated onto the housing 112 so as to also contact the faceplate 110. Depending on the coating technique, the portions of the connectors 108 that connect to complementary plugs and/or connectors of a power source may be masked, however with some coating techniques no masking may be used. For example, with spraying and/or painting, spraying and/or painting of the one or more curable raw materials onto the thermally conductive flexible material 208 may occur in a manner that coats the housing 112 and a portion of the faceplate 110, but avoids spraying and/or painting the connectors 108. With dipping, however, masking may be used to prevent the portions of the connectors 108 that connect to complementary plugs and/or connectors of a power source from being coated with the or more curable raw materials of the electrically conductive flexible material 210 and/or the electrically conductive flexible material 210 may later abraded from such portions; alternatively, dipping may occur starting from an end of the electrical component 102 opposite the connectors 108 and stop when the faceplate 110 is reached.

[0093] At a block 504, the one or more curable raw materials, of the electrically conductive flexible material 210, as coated on the thermally conductive flexible material 208, is air- dried. For example, the air-drying may occur at an ambient temperature (e.g. about 20°C to about 25°C) to allow solvent of the one or more curable raw materials to generally dissipate. The air-drying may be assisted with fans, blowers, and the like, but may include leaving the one or more curable raw materials, of the electrically conductive flexible material 210, as coated on the thermally conductive flexible material 208 to sit. The air drying may occur in a ventilated area, and the like. Furthermore, when the one or more curable raw materials, of the electrically conductive flexible material 210 is applied in coats, air-drying may occur between the coats. As such, the block 502 and the block 504 may occur in conjunction with each other, and/or alternating with each other any suitable number of times.

[0094] After the block 506 is implemented, at a block 506, the one or more curable raw materials, of the electrically conductive flexible material 210, as coated on the thermally conductive flexible material 208 and air-dried, is heated to a given temperature (e.g. a third given temperature as compared to the first given temperature and the second given temperature used to cure and/or stabilize the thermally conductive flexible material 208). The given temperature may be the same or different as the second given temperature as described above, to cure the one or more curable raw materials into the electrically conductive flexible material 210. The heating may occur in a thermal chamber and/or a TVAC and the like. For some sprayable, solvenated liquid uncured silicone materials, the given temperature may be about 150°C, which is greater than the first given temperature of about 100°C to about 120°C used to cure some liquid uncured silicone materials of the thermally conductive flexible material 208 and may be about the same as the second given temperature of about 150°C used to stabilize some partially cured silicone materials of the thermally conductive flexible material 208.

[0095] The cure of the one or more curable raw materials into the electrically conductive flexible material 210 at the block 506 may also result in bonding and/or cross-linking between the materials 208, 210, with the given temperature at which the electrically conductive flexible material 210 is cured selected accordingly. Put another way, contacting surfaces of the thermally conductive flexible material 208 and the electrically conductive flexible material 210 may be chemically cross-linked to each other during the curing at the block 506. Such bonding and/or cross-linking may be promoted by using a same and/or similar backbone material for the materials 208, 210. As such, it is understood the one or more curable raw materials of the electrically conductive flexible material 210 may include active chemical constituents configured to react with, and/or bond to, a surface of the thermally conductive flexible material 208. Regardless, the bonding and/or cross-linking between the materials 208, 210 may assist with a combined flexibility of the materials 208, 210.

[0096] It is further understood that, as described above, in implementation of the method 300, the method 400 and/or the method 500, that portions of the electromagnetic component 102 that are to electrically connect with an external power source may be coated with the materials 208, 210, and may be removed (and/or prevented) by one or more of: masking such portions prior to implementation of the method 300, the method 400 and/or the method 500, and/or abrading the materials 208, 210 from such portions after implementation of the method 300, the method 400 and/or the method 500 and/or by preventing such portions from being coated with the materials 208, 210 via molds and/or controlled spraying and/or controlled painting and/or controlled dipping. As such, it is understood that the method 300, the method 400 and/or the method 500 may be used to coat a portion of an electromagnetic component but not necessarily all of an electromagnetic component.

[0097] Hence, while the examples of the method 300, the method 400 and/or the method 500 have been described with respect to coating only the electromagnetic component 102, the electrical connectors 108 and the faceplate 110 with the materials 208, 210, in other examples, the method 300, the method 400 and/or the method 500 may be used to coat (all and/or a portion of) the electromagnetic machine 100 with the materials 208, 210. Alternatively, the method 300, the method 400 and/or the method 500 may be used to coat the entire electromagnetic component 102, as assembled with the pole portion 103 and the backplane 114, with the materials 208, 210, prior to, or after, attachment (e.g. by pouring and curing, and the like) of the housing 112 (and/or the faceplate 110 and the electrical connectors 108 when not initially attached). However, the method 300, the method 400 and/or the method 500, and/or variations thereof, may be used to coat at least a portion of any suitable electromagnetic components.

[0098] It is understood that for the purpose of this specification, language of “at least one of X, Y, and Z” and “one or more of X, Y and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY, YZ, XZ, and the like). Similar logic can be applied for two or more items in any occurrence of “at least one...” and “one or more...” language.

[0099] The terms “about”, “substantially”, “essentially”, “approximately”, and the like, are defined as being “close to”, for example as understood by persons of skill in the art. In some examples, the terms are understood to be “within 10%,” in other examples, “within 5%”, in yet further examples, “within 1%”, and in yet further examples “within 0.5%”. [00100] Persons skilled in the art will appreciate that there are yet more alternative examples and modifications possible, and that the above examples are only illustrations of one or more examples. The scope, therefore, is only to be limited by the claims appended hereto.