Thermal management of high power inductors

An inductor assembly includes a housing including a base, a sidewall, and an insert. The base and the sidewall define a cavity and the insert being positioned within the cavity. A core assembly is positioned within the cavity. The core assembly includes a core and a plurality of windings wrapped about the core and disposed between the sidewall and the insert. A flow path is formed in the housing for receiving a coolant to remove heat from the core assembly.

BACKGROUND

Embodiments of the present disclosure relate to an inductor assembly, and more particularly, to liquid cooling of an inductor assembly such as used in aerospace applications.

Current flowing through inductor assemblies generally produces heat. In some types of inductor assemblies, the heat generated by current traversing the conductive wires is sufficient to limit the current carrying capability, e.g. the current rating, of the inductor assembly. It can also influence core size, core material selection, and/or the reliability of the filtering functionality provided by the core. Conventional inductor assemblies therefore typically have a maximum core temperature limit and corresponding current limit.

Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved inductor assemblies that allows for improved current carrying capability.

BRIEF DESCRIPTION

According to an embodiment, an inductor assembly includes a housing including a base, a sidewall, and an insert. The base and the sidewall define a cavity and the insert being positioned within the cavity. A core assembly is positioned within the cavity. The core assembly includes a core and a plurality of windings wrapped about the core and disposed between the sidewall and the insert. A flow path is formed in the housing for receiving a coolant to remove heat from the core assembly.

In addition to one or more of the features described above, or as an alternative, in further embodiments the flow path includes at least one first channel, the at least one first channel extending within a plane defined by the base.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one first channel is aligned with one of the plurality of windings.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one first channel has an arcuate contour.

In addition to one or more of the features described above, or as an alternative, in further embodiments a radius of the at least is equal to an outer diameter of the core.

In addition to one or more of the features described above, or as an alternative, in further embodiments a portion of the at least one first channel extends at an angle to the base.

In addition to one or more of the features described above, or as an alternative, in further embodiments the portion of the at least one first channel is formed in the sidewall.

In addition to one or more of the features described above, or as an alternative, in further embodiments the flow path includes at least one second channel arranged in fluid communication with the at least one first channel, wherein a portion of the at least one second channel extending at an angle into the base.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one second channel is formed in the insert.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one second channel includes an angular section having an apex opposite the base.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one second channel includes a plurality of angular sections arranged in series.

In addition to one or more of the features described above, or as an alternative, in further embodiments the at least one second channel includes a plurality of vertical sections fluidly coupled by a plurality of planar sections.

In addition to one or more of the features described above, or as an alternative, in further embodiments comprising a base cover affixed to the base of the housing.

In addition to one or more of the features described above, or as an alternative, in further embodiments the housing of the inductor assembly further comprises another sidewall and another insert, the base and the another sidewall defined another cavity, the another insert being positioned within the another cavity, another core assembly being receivable within the another cavity.

In addition to one or more of the features described above, or as an alternative, in further embodiments the flow path includes a first flow path for removing heat from the core positioned within cavity and a second flow path for removing heat from the core positioned within the another cavity.

In addition to one or more of the features described above, or as an alternative, in further embodiments the flow path further comprises an inlet and an outlet, both the first flow path and the second flow path being arranged in fluid communication with the inlet and the outlet.

In addition to one or more of the features described above, or as an alternative, in further embodiments the first flow path and the second flow path are symmetrical.

In addition to one or more of the features described above, or as an alternative, in further embodiments flow path additionally includes a bypass flow path arranged in parallel with the first flow path and the second flow path.

DETAILED DESCRIPTION

With reference toFIGS. 1-3, an example of an inductor assembly20is shown. The inductor assembly20includes a housing22having a base23and an integral sidewall25extending, such as perpendicularly for example, from the base23. The base23and sidewall25of the housing22cooperate to define a cavity24of the housing22within which a core assembly26is received. The core assembly26includes a core28and a plurality of windings30wrapped about the core28. Each core28includes a central opening32and an insert34of the housing22seats within the central opening32to restrict movement of the core28relative to the housing22. The insert34is in thermal communication with the core28and the windings30wrapped about the core28. In an embodiment, the remaining inner volume of the cavity24is filled with a thermally conductive potting material. This potting material facilitates conduction of heat from the core assembly26, such as to the base23and the insert34of the housing22for example. In an embodiment, a cover36is disposed within the cavity24in overlapping arrangement with the core assembly26. As shown, the cover36includes a plurality of openings38through which a portion of the heat generated by the core assembly26is dissipated.

In the non-limiting embodiment ofFIG. 1, groups of windings30are spaced about the outer periphery of the core28. Another example of a configuration of the windings30is shown inFIG. 3. In the embodiment, individual windings30are equidistantly spaced about the core28. However, it should be understood that any suitable configuration of the windings30is contemplated herein. In each of the embodiments, the, the heat flux at the inner diameter of the core28is greater than at the outer diameter of the core28.

In an embodiment, the housing22may be designed to support a plurality of core assemblies26. For example, in the illustrated, non-limiting embodiments, the inductor assembly20includes a first core assembly26aarranged within a first cavity24aand a second core26bassembly arranged within a second cavity24b. The first and second core assembly26a,26bmay be substantially identical, or alternatively, may have varying configurations. Although two core assemblies26a,26bare illustrated, it should be understood that embodiments including a single core assembly, or alternatively, more than two core assemblies are within the scope of the disclosure.

With reference now toFIG. 4, the inductor assembly20is shown mounted adjacent an exterior surface42of a generator housing40. In such embodiments, the generator housing40may be mounted to a portion of a gas turbine engine of an aircraft, such as an accessories mounting and drive assemblies (AMAD) for example. As shown, a plurality of connector flanges44extend outwardly from various locations about a periphery of the housing22. In the illustrated, non-limiting embodiment, the connector flanges44are arranged centrally between the first end46of the housing22and a second, opposite end48of the housing22. The first end46faces toward the generator housing40, and the second end48faces outward from the generator housing40. When the inductor housing22is positioned relative to the generator housing40, each of the plurality of connector flanges44is aligned with and affixed to a corresponding standoff50extending from the generator housing40. An axial length of each of the standoffs50is greater than the distance between the first end46of the inductor housing22and a connector flange44such that when the inductor assembly20is mounted to the generator housing40, the first end46of the inductor assembly20is offset therefrom. As a result, thermal coupling between the inductor assembly20and the generator housing40is limited to the interface between the connector flanges44and standoffs50.

A flow of coolant, such as oil or glycol water for example, is used to cool the one or more core assemblies26of the inductor assembly20.

With reference now toFIGS. 5-10, a flow path60through which coolant flows to remove heat from the core assembly26of the inductor assembly20is formed in the housing22. In an embodiment, the flow path60is machined into the inductor housing22. In another embodiment, the flow path60may be formed simultaneously with the housing22, such as via an additive manufacturing process for example. A cover (not shown) is affixed to the base23of the inductor housing22, such as via brazing for example, to restrict the flow of coolant to within the flow path60.

The flow path60formed in the housing22typically includes an inlet62and an outlet64disposed adjacent opposite sides of the housing22. In embodiments where the housing22includes a first cavity24aand a second cavity24b, and is therefore configured to receive a first core assembly26aand a second core assembly26b, the inlet62and outlet64may be positioned centrally between the sidewalls25associated with the first and second core assemblies26a,26b. In such embodiments, the flow path60may include a first flow path66for cooling the first core assembly26aand a second flow path68for cooling the second core assembly26b. However, it should be understood that embodiments including a single flow path for cooling multiple core assemblies are also within the scope of the disclosure. In an embodiment, the first and second flow paths66,68are symmetrical about an axis A, extending between the inlet62and the outlet64. The flow path60may additionally include a bypass flow path70directly coupling the inlet62and the outlet64and arranged at the central portion of the housing22, between the core assemblies26a,26b.

For ease of understanding, only the first flow path66of each of the various coolant flow path configurations illustrated herein will be described. Each configuration of the first flow path66includes at least one first channel formed in the surface of the base23defining the first end46of the housing22. The first flow path66additionally includes at least one second channel74formed over the height of the insert34. As a result, the coolant provided to first flow path66of the housing22cools not only the portion of the housing22adjacent a first end surface (not shown) of the core assembly26, but also cools the insert34arranged in thermal communication with the inner diameter of the core assembly26.

Heat is configured to conduct from the core assembly26, through a potting material, to the flow path60formed in the housing22. In operation, a coolant is provided from the inlet62to the first flow path66. As the coolant moves through the first flow path66, the coolant not only absorbs heat conducted to the housing22from the adjacent core assembly26, but also absorbs heat via convection between the housing22and the coolant. The heated coolant is then provided to the outlet64where the heat may be removed from the coolant by a liquid or air cooled heat exchanger before returning the coolant to the inlet62.

In the non-limiting embodiment illustrated inFIGS. 5-7, the first flow path66includes at least one first channel72having a non-linear configuration. As shown, the at least one first channel72includes a serpentine configuration extending between an interior portion of the base23, arranged generally adjacent the insert34and an inner diameter of the first core assembly26a, and outer portion of the base23, located generally adjacent the outer diameter of the first core assembly26. The configuration of the at least one first channel72may align with each of the plurality of windings30of the core assembly26a.

The first flow path66additionally includes at least one second channel74(best shown inFIG. 7) in fluid communication with the first channel72. In the illustrated, non-limiting embodiment, the first flow path66includes a plurality of second channels74, separated from one another and spaced about the periphery of the insert34. The plurality of second channels74extend through the insert34of the housing22, for example, in a direction generally perpendicular to the base23and the first channel72. In the illustrated, non-limiting embodiment, the second channels74have a generally triangular configuration such that the portion of each second channel74positioned furthest from the base23includes an apex76. Because the heat flux of the first core assembly26ais greatest adjacent the inner diameter thereof, inclusion of these second channels74, which extend through the insert34over at least a portion of the height of the first core assembly26a, substantially cools the inner diameter of the first core assembly26a.

In the illustrated, non-limiting embodiment, the first flow path66is divided into two parallel and substantially identical and/or symmetrical portions such that each portion removes heat from a corresponding portion of the first core assembly26a. Accordingly, as shown, each of these portions of the first flow path66includes both first and second channels72,74. However, it should be understood that embodiments where the first flow path66includes only a single path configured to cool the first core assembly26aare also within the scope of the disclosure.

With reference now toFIGS. 8-10, in another embodiment, the first flow path66includes a plurality of concentric first channels72arranged in fluid communication. In the illustrated, non-limiting embodiment, the first channels72are generally arcuate in shape such that a first channel72ais generally defined by a first radius, and another first channel72bis generally defined by a second radius. The second radius is smaller than the first radius. In an embodiment, the radius of the first channel72ais generally equal to an outer radius of a core assembly26.

The first flow path66additionally includes at least one second channel74arranged generally concentrically with the first channels72. The at least one second channel74has a third radius, smaller than the second radius. In an embodiment, the radius of at least one the second channel74is generally equal to a radius of the insert34, such that the second channel74is formed within the insert34. In an embodiment, the first channel72a, another first channel72b, and second channel74are arranged in parallel with respect to the flow of coolant, via an axially extending connector78.

As previously described, in each of the embodiments illustrated inFIGS. 8-10, the second channel74is formed in a portion of the insert34. The second channel74is configured to extend both peripherally and vertically through the insert34. Accordingly, as shown, flow of coolant within the second channel74of the first flow path66is configured to repeatedly move between a first plane, aligned with the base23, and a second parallel plane offset from the first plane. In an embodiment, the second plane is defined by an upper surface80of the insert34, or alternatively, at any location between the upper surface80of the insert34and the base23.

In the illustrated, non-limiting embodiment ofFIG. 8, the portion of the first flow path66defined by the second channel74includes a plurality of angular sections arranged in series. Similar to the embodiment ofFIG. 7, each angular section is triangular in shape and includes an apex76disposed at the furthest portion of the second channel74relative to the base23. In another embodiment, illustrated inFIG. 9, the portion of the first flow path66defined by the second channel74is configured to move arcuately within both the first plane and the second plane. As shown, a planar section84extends between adjacent parallel, vertical sections82of the second channel74. The location of each planar section84varies sequentially between the first plane defined by the base23and the second plane, such as defined by the upper surface80of the insert34for example.

In an embodiment, best shown inFIG. 10, one of the first channels72of the flow path66, such as channel72afor example, is configured to extend both peripherally and vertically through the sidewall25of the housing22. For example, the portion of the first flow path66defined by the first channel72may be configured to move arcuately within both the first plane defined by the base23and a second, parallel plane. In an embodiment, the second parallel plane may be located at any position over the height of the sidewall25. As shown inFIG. 10, a planar section86extends between adjacent vertical sections88formed in the first channel72. Although the first channel72is shown as having a specific configuration, it should be understood that embodiments having any flow configuration extending both peripherally and vertically through the sidewall25are within the scope of the disclosure. Further, it should be understood that any configured of the flow path formed in the base of the housing22and extending at least partially over the height of the insert34of the housing22is within the scope of the disclosure.

The overall configuration of the flow path60may be customized to maximize the heat transfer between the coolant and the hot spots of the core assembly26, thereby reducing the temperature of the core28and windings30to below their respective material ratings. Further, by integrating the coolant flow into the housing22of the inductor assembly20, the need for additional components, and therefore the overall size of the assembly20may be reduced. Each of the non-limiting embodiments illustrated herein includes a plurality of narrow flow channels to ensure the light weight of the housing22and inductor assembly20, as well as a reduced pressure drop in the inductor assembly20, which is critical for aerospace applications.