Cooling system and method using integration of pressure difference cooling and self-excited oscillating heat pipes

Abstract

A cooling system and method using the integration of the pressure difference between a cooling pipe and a self-excited oscillating heat pipe. [Solution] This disclosure relates to a cooling system. The cooling system includes a casing and at least two fins. The casing surrounds one or more electronic devices. At least two fins extend from the outer surface of the casing. Each of the at least two fins is configured to guide airflow to create a high-pressure region and a low-pressure region. The casing includes a duct assembly having a duct inlet and a duct outlet. The duct inlet is configured to be located in the high-pressure region, and the duct outlet is configured to be located in the low-pressure region.

Description

Technical Field

[0001] This specification generally relates to an apparatus for cooling a structure, and more particularly, to an apparatus for cooling a structure that utilizes a pressure difference to increase an air flow.

Background Art

[0002] Electric aircraft rely on motors to generate lift and / or thrust. Electric aircraft also use various other electronic devices such as motors and inverters to control aircraft functions and perform various tasks. One type of electric aircraft can be an electric vertical takeoff and landing aircraft (eVTOL). These electronic devices can be packaged together within a casing. These electronic devices can generate significant heat, which requires cooling to maintain the electronic equipment within an optimal operating temperature range. Conventional cooling systems can include dissipating heat using the surfaces of the casing and cooling fins among other types of cooling devices. Conventional cooling systems can result in insufficient heat dissipation capabilities around the surface of the package of electronic equipment, which can lead to a decrease in cooling efficiency and a decrease in electronic functionality.

Summary of the Invention

[0003] In one embodiment, a cooling system is provided. The cooling system includes a casing and at least two fins. The casing surrounds one or more electronic devices. At least two fins extend from an outer surface of the casing. Each of the at least two fins is configured to induce an air flow to create a high-pressure region and a low-pressure region. The casing includes a duct assembly having a duct inlet and a duct outlet. The duct inlet is configured to be disposed in the high-pressure region, and the duct outlet is configured to be disposed in the low-pressure region.

[0004] In another embodiment, an electric motor assembly is provided. The electric motor assembly includes a motor housing, a motor within the motor housing, a casing, one or more electronic devices, and at least two fins. The casing has an outer surface and opposing inner surfaces that define an internal cavity of the casing. One or more electronic devices are located within the internal cavity of the casing, surrounded by the inner surfaces. At least two fins extend from the outer surface of the casing. Each pair of at least two fins and the outer surface of the casing define an internal cavity of fins. Each of the at least two fins is configured to guide airflow to generate high-pressure and low-pressure regions. The casing includes a duct assembly having a duct inlet and a duct outlet. The duct inlet is configured to be located in the high-pressure region, and the duct outlet is configured to be located in the low-pressure region.

[0005] In yet another embodiment, an electric vertical take-off and landing (VTOL) aircraft is provided. The VTOL aircraft includes an electric motor assembly. The electric motor assembly includes a motor housing, a motor within the motor housing, a casing, one or more electronic devices, and at least two fins. The casing has an outer surface and opposing inner surfaces that define an internal cavity of the casing. One or more electronic devices are located within the internal cavity of the casing, surrounded by the inner surfaces. At least two fins extend from the outer surface of the casing. Each pair of at least two fins and the outer surface of the casing define an internal cavity of fins. Each of the at least two fins is configured to guide airflow to generate high-pressure and low-pressure regions. The casing includes a duct assembly having a duct inlet and a duct outlet. The duct inlet is configured to be located in the high-pressure region, and the duct outlet is configured to be located in the low-pressure region.

[0006] These and additional features provided by the embodiments described herein will be better understood by referring to the detailed description below in conjunction with the drawings. [Brief explanation of the drawing]

[0007] The embodiments shown in the drawings are for illustrative purposes only and are not intended to limit the subject matter defined by the claims. Further detailed descriptions of the exemplary embodiments can be understood in conjunction with the following drawings, in which similar structures are indicated by similar reference numerals. [Figure 1] Figure 1 schematically shows a system including a motor, a casing, a plurality of fins, and a front cross-sectional view of a propeller assembly according to one or more embodiments shown and described herein. [Figure 2] Figure 2 schematically shows an isolated view of a self-excited oscillating heat pipe incorporated into a fin and connected to the inner surface of a casing, according to one or more embodiments shown and described herein. [Figure 3A] Figure 3A schematically shows a partial cross-sectional view obtained along line 3A–3A of an example of the two-part cooling system of Figure 2 according to one or more embodiments shown and described herein. [Figure 3B] Figure 3B schematically shows a cross-sectional view obtained along line 3B–3B of an example of the two-part cooling system of Figure 2 according to one or more embodiments shown and described herein. [Figure 3C] Figure 3C schematically shows a front plan view of an example of the two-part cooling system of Figure 2, according to one or more embodiments shown and described herein. [Figure 3D] Figure 3D schematically shows a top view of an example of the two-part cooling system of Figure 2, according to one or more embodiments shown and described herein. [Figure 3E] Figure 3E schematically shows a top view obtained along line 3E–3E of an example of a two-part cooling system of Figure 3D according to one or more embodiments shown and described herein. [Figure 4]Figure 4 schematically shows a partial cross-sectional view obtained along line 3A–3A of an example of the two-part cooling system of Figure 2 according to one or more embodiments shown and described herein, where the airflow path is shown. [Figure 5] Figure 5 schematically shows a partial cross-sectional view obtained along lines 5–6 of an example of the two-part cooling system of Figure 4, according to one or more embodiments shown and described herein, illustrating conductional and convective heat transfer in the airflow. [Figure 6] Figure 6 schematically shows an eVTOL having an example of the two-part cooling system shown in Figure 1, according to one or more embodiments shown and described herein. [Modes for carrying out the invention]

[0008] Embodiments of the present disclosure relate to a cooling system for an electric vertical take-off and landing (eVTOL) aircraft. The eVTOL includes a motor and inverter package. The package may include a metal casing, which may house various electronic devices. One or more fins may be connected to the outer surface of the casing. The cooling system may use a two-part cooling structure, one of which includes a self-excited oscillating heat pipe (PHP) assembly partially integrated into the casing, and the second part including a series of ductwork penetrating the casing, which utilizes a pressure difference to increase the airflow around the casing and fins, thereby increasing heat transfer.

[0009] A duct inlet may be installed between two of several external fins attached to the outer surface of the casing. The duct inlet may allow airflow to pass through an internal channel constructed within the casing. The airflow may be exhausted to the outside of the casing through a duct outlet. The duct inlet and outlet may be positioned such that the orientation of the several fins arranged around the duct inlet and outlet creates a high-pressure zone near the duct inlet and a low-pressure zone near the duct outlet, thereby increasing the airflow through the duct and the channel. For example, the angles of attack of the several fins may be arranged to create this pressure difference. This airflow helps in heat conduction from electronic devices installed inside the casing. In some embodiments, a PHP (Heat Purifier) ​​may be installed within the casing and fins. The PHP may contain alternating liquid and gaseous slags, which can further improve the cooling effect of the cooling system by enhancing heat transfer from the electronic devices to the fins.

[0010] Conventional cooling systems restrict heat dissipation and concentrate heat in the casing and fin portions closest to the heat source. This does not efficiently utilize the entire surface area of ​​the casing and fins, as heat is not dissipated throughout the casing and fins, and removes less heat from the heat source for which the casing and fins are designed to be cooled compared to the present system. A two-part cooling structure is provided, one of which includes a self-excited oscillating heat pipe (PHP) assembly at least partially incorporated within the fins, and the second part including a series of ductwork penetrating the casing, which utilizes a pressure difference to increase airflow around the casing and fins, thereby increasing heat transfer, more effectively transferring heat throughout the casing and fins, more efficiently utilizing the total surface area of ​​the casing and fins, and increasing heat dissipation throughout the casing and fins compared to conventional cooling systems. Advantageously, the cooling system described herein utilizes a two-phase heat transfer mechanism to remove heat from at least one heat-generating device. The first heat transfer mechanism is configured to utilize a self-oscillating heat pipe to efficiently transfer heat throughout the heat pipe running through the case. The second mechanism re-inducts the airflow into the cavity of the case, thereby reducing the thermal resistance between the heat-generating device and the airflow and improving heat transfer.

[0011] Referring next to Figure 1, an example embodiment of system 100 is shown. System 100 includes a casing 110, a motor 101, one or more electronic devices 113, a propeller 102, a propeller shaft 103, and an exemplary two-part cooling system 126. One or more electronic devices 113 are located within an internal cavity 111 (i.e., enclosure) of the casing. That is, one or more electronic devices 113 are surrounded or housed by the casing 110. Multiple fins 120 extend from the outside of the casing 110. The propeller shaft 103 is connected to the motor 101 and the propeller 102. The casing 110 may have a pass-through 117 to allow the propeller shaft 103 to pass through from the motor 101 to the propeller 102. The propeller 102 may provide lift, thrust, or a combination of lift and thrust. Any number of fins may be included in the multiple fins 120. The arrangement of the components of System 100 in Figure 1 is for illustrative purposes only, and it should be understood that other arrangements are possible.

[0012] One or more electronic devices 113 located within the casing cavity 111 may be one or more different electronic devices 113. One or more electronic devices 113 may be an inverter package or circuit, a gate drive, and / or similar. Alternatively, or in addition, one or more electronic devices 113 may also include a capacitor, an insulated gate bipolar transistor, a power MOSFET, or any other electronic device. One or more electronic devices 113 may be a power device package 134 (Figure 3A) which may include various layers 135 (Figure 3A) such as a thermal conductor, an electrical insulator, and a thermal interface layer. One or more electronic devices 113 may be a heat source for system 100, as electronic devices generate heat during operation.

[0013] Referring next to Figures 2 and 3A–3E, the casing 110 surrounding one or more electronic devices 113 can be any shape, including but not limited to cylindrical, toroidal, rectangular, and / or similar shapes. The casing 110 can be any material, including but not limited to aluminum, steel, plastic, etc. The casing 110 includes a wall 122 comprising an outer surface 124a and an inner surface 124b located opposite the outer surface 124a, a pair of side wall surfaces 124c, 124d, and a pair of end surfaces 124e, 124f, thereby defining the internal cavity 111 of the casing. That is, in some embodiments, the wall 122 may be continuous. In other embodiments, multiple wall sections define the wall 122. In some embodiments, multiple casings 110 may be arranged together, and each casing 110 is fitted with at least one fin 120a of a plurality of fins 120.

[0014] In some embodiments, the casing 110 and its components may be formed using additive manufacturing techniques or processes, such as 3D printing. As used herein, the term “additive manufacturing techniques or processes” generally refers to a manufacturing process in which three-dimensional components are “build-up” layer by layer by which consecutive layers of material are given on top of each other. The consecutive layers generally fuse together to form a monolithic component that may have various integral sub-components. Additive manufacturing techniques are typically described herein as enabling the manufacture of complex objects by constructing objects vertically, point by point, layer by layer, but other manufacturing methods are also possible and fall within the scope of this subject. For example, while the discussion herein refers to the addition of material to form consecutive layers, those skilled in the art will understand that the methods and structures disclosed herein may be practiced by any additive manufacturing technique or process. For example, embodiments of the present invention may use a layer addition process, a layer removal process, or a hybrid process.

[0015] Appropriate additive manufacturing technologies relating to this disclosure include, for example, fused deposition modeling (FDM), selective laser sintering (SLS), 3D printing by inkjet and laser jet, sterolography (SLA), direct selective laser sintering (DSLS), electron beam sintering (EBS), electron beam melting (EBM), laser-engineered net shaping (LENS), laser net shape fabrication (LNSM), direct metal deposition (DMD), digital light processing (DLP), direct selective laser melting (DSLM), selective laser melting (SLM), direct metal laser melting (DMLM), and other known processes.

[0016] The additive manufacturing processes described herein may be used to form components using any suitable material. For example, the material may be plastic, metal, concrete, ceramic, polymer, epoxy, photocurable resin, or any other suitable material, and may be solid, liquid, powder, sheet material, wire, or any other suitable form. More specifically, according to the embodiments of this subject, the additively manufactured components described herein may be formed in part, whole, or in combination with materials including, but not limited to, pure metals, nickel alloys, chromium alloys, titanium, titanium alloys, magnesium, magnesium alloys, aluminum, aluminum alloys, and nickel or cobalt-based superalloys (e.g., those available from Special Metals Corporation under the name Inconel®). These materials are examples of materials suitable for use in the additive manufacturing processes described herein and may generally be referred to as “additive materials.”

[0017] In addition, one of ordinary skill in the art will understand that various materials and methods for combining those materials are used and contemplated to be within the scope of the present disclosure. As used herein, references to "fusing" can refer to any suitable process for creating a bonding layer of any of the above-described materials. For example, where an object is formed of a polymer, fusing can refer to creating a thermosetting bond between polymer materials. Where the object is an epoxy, the bond can be formed by a crosslinking process. Where the materials are ceramics, the bond can be formed by a sintering process. Where the materials are powder metals, the bond can be formed by a melting or sintering process. One of ordinary skill in the art will understand that other methods of fusing materials for creating components by additive manufacturing are possible and that the presently disclosed subject matter can be practiced by such methods.

[0018] In other embodiments, the casing 110 can be formed by casting, machining, or any other suitable manufacturing technique.

[0019] In some embodiments, each fin 120a can be attached to the casing 110, such as extending from an external surface 124a. Each fin 120a can be attached to and disposed so as to extend between terminal surfaces 124e, 124f and between sidewall surfaces 124c, 124d. Thus, in some embodiments, each fin 120a can extend along the length of the external surface 124a of the casing between terminal surfaces 124e, 124f. This is non-limiting, and in other embodiments, each fin 120a can have a non-uniform length or any length and not necessarily be equal to the length of other fins 120a.

[0020] Each fin 120a can be attached to the casing 110 by a variety of methods, including but not limited to soldering, brazing, and welding. In other embodiments, each fin 120a and the casing 110 may be made from a single piece of material; that is, each fin 120a may be integrated into the casing 110 as a single monolithic structure. In some embodiments, each fin 120a and the casing 110 may be formed from additive manufacturing techniques or processes, such as 3D printing. In other embodiments, each fin 120a and / or the casing 110 may be formed by casting, machining, or any other suitable manufacturing technique.

[0021] Each fin 120a may have any shape, including but not limited to cylindrical, cuboidal, rectangular, square, and / or similar shapes. Furthermore, each fin 120a may have a planar shape or may extend in multiple angles or directions with respect to the Cartesian coordinate system and the outer surface 124a (for example, its shape may be manipulated). Each fin 120a of the plurality of fins 120 is configured to cause a pressure difference from one side to the other, as will be described in more detail herein.

[0022] Referring further to FIGS. 2, 3A - 3E, and FIG. 5, an exemplary two - part cooling system 126 includes a self - oscillating heat pipe assembly 130 and a duct assembly 132. The self - oscillating heat pipe assembly 130 can include at least one self - oscillating heat pipe 136 that is fluidly connected to the inner surface 124b of the casing 110, and can be incorporated within the inner cavity 111 of the casing and / or within the thickness of the casing between the inner surface 124b and the outer surface 124a. In other embodiments, at least one self - oscillating heat pipe 136 can be at least partially incorporated into a fin internal cavity 138 defined by the inner surface 140a of an adjacent pair of fins 120a among the plurality of fins 120 and the outer surface 124a of the casing. Each fin 120a further includes an opposite outer surface 140b. In other embodiments, at least a portion of at least one self - oscillating heat pipe 136 is disposed within the fin internal cavity 138 and / or is fluidly connected to the fin internal cavity 138.

[0023] At least a portion of at least one self - oscillating heat pipe 136 can also be disposed within the inner surface 124b of the casing 110 and / or be fluidly connected to such inner surface 124b, and further or alternatively, another portion can be disposed within the fin internal cavity 138 and / or be fluidly connected to such fin internal cavity 138 by any of a variety of methods including, but not limited to, solder or thermal grease. It should be understood that thermal grease can enable more efficient heat transfer between at least one self - oscillating heat pipe 136 and the inner surface 124b of the casing 110 and / or the fin internal cavity 138. In other embodiments, at least one self - oscillating heat pipe 136 can be fluidly connected to the inner surface 124b of the casing 110 and / or can be fluidly connected to the fin internal cavity 138 via a snap - fit and / or via a fixing portion including, but not limited to, screws, rivets, nuts and bolts, welding, adhesives, etc.

[0024] The self-oscillating heat pipe assembly 130 may have a closed loop structure and may further include an evaporation section 142, which may be located on or adjacent to one or more electronic devices 113 within an internal casing cavity 111 defined by an internal surface 124b. In a non-limiting example, R404A may be used as a refrigerant passing through the self-oscillating heat pipe assembly 130. When one or more electronic devices 113 generate heat during operation, this heat is transferred to the evaporation section 142 of the self-oscillating heat pipe assembly 130. The condensing section 144 of the self-oscillating heat pipe assembly 130 may be located away from one or more electronic devices 113 and, in some embodiments, may be located within the airflow of a propeller 102 (not shown). The refrigerant may move between the evaporation section 142 and the condensing section 144, undergoing transformation between gas and liquid phases. Such a transformation allows for the absorption and release of heat, resulting in heat being absorbed from one or more electronic devices 113 and vapor being released from the casing 110. This arrangement may offer advantages such as higher heat transfer capacity, greater heat flux diffusion, ability to withstand G-forces on the aircraft, performance insensitivity to attitude, and structural simplicity.

[0025] In the embodiments shown in Figures 3A–3E, as will be described in more detail herein, the self-oscillating heat pipe assembly 130 is incorporated into two adjacent or neighboring casings 110 and is configured to absorb heat from one or more electronic devices 113 and release vapor from the casings 110 and duct assemblies 132. It should be understood that the self-oscillating heat pipe assembly 130 may be incorporated into any suitable number of casings 110, internal cavities 111, and / or similar. In other embodiments, the system 100 may include a plurality of self-oscillating heat pipe assemblies 130. Each of the plurality of self-oscillating heat pipe assemblies 130 may be incorporated into a corresponding casing such that the number of self-oscillating heat pipe assemblies 130 is equal to the number of casings 110 in the system 100.

[0026] In yet another embodiment, each of the multiple self-excited vibrating heat pipe assemblies 130 may be incorporated into a casing 110. In non-limiting examples, there may be six self-excited vibrating heat pipe assemblies 130 and twelve casings 110, or five self-excited vibrating heat pipe assemblies 130 and fifteen casings 110.

[0027] In yet another embodiment, multiple condensing units 144 may be incorporated into the casing 110, fins 120a, etc., and multiple evaporation units 142 may be connected to the inner surface 124b of the casing 110.

[0028] Referring next to Figure 5, the self-oscillating heat pipe assembly 130 may alternately contain liquid and vapor slags 170a and 170b, respectively, which, as described in detail herein, can further improve the cooling effect of the two-part cooling system 126 by improving heat transfer from one or more electronic devices 113 to the multiple fins 120 via the duct assembly 132.

[0029] It should be understood that the self-excited oscillating heat pipe assembly 130 is configured to efficiently transfer heat input from one or more electronic devices 113 to the duct assembly 132, as will be described in more detail herein.

[0030] Referring further to Figures 2, 3A–3E and then to Figure 4, the duct assembly 132 includes a fluid duct 145 having a duct inlet 146 extending from the outer surface 124a of the wall 122 in one fin internal cavity 138, and is fluidly connected via the fluid duct 145 to a duct outlet 152 located in another or different fin internal cavity 138. The duct inlet 146 is fluidly connected to the casing internal cavity 111 and the fin internal cavity 138 so that the airflow into the fin internal cavity 138 is guided by the duct inlet 146 into the casing internal cavity 111. As shown in Figure 4, the duct inlet 146 is located on the high-pressure side of the fin 120a. In some embodiments, the casing internal cavity 111 includes several heat-enhancing structures, such as several ribs 150, to assist in the removal of heat generated by one or more electronic devices 113. In other embodiments, the casing cavity 111 includes a plurality of recesses to assist in the removal of heat generated by one or more electronic devices 113. The plurality of ribs 150 may be in the shape of metal foam or porous metal and are configured to assist in the removal of heat generated by one or more electronic devices 113.

[0031] The side wall surface 124c of the casing 110 includes a plurality of elongated holes 148 or voids to fluidly communicate the internal casing cavity 111 with the outside of the casing 110. At least some of the plurality of elongated holes 148 may be located below or lower than the duct inlet 146 in the vertical direction. Furthermore, the plurality of elongated holes 148 may be arranged such that the airflow out of the plurality of elongated holes 148 is perpendicular to the airflow flowing into the duct inlet 146, as is most detailed in Figure 4.

[0032] The duct outlet 152 is fluidically connected to the casing internal cavity 111 and the fin internal cavity 138 so that airflow from the casing internal cavity 111 can be guided into the fin internal cavity 138 by the duct outlet 152. As shown in most detail in Figure 4, the duct outlet 152 is located on the low-pressure side of the fin 120a. Thus, the amount of airflow between the duct inlet 146 and the duct outlet 152 may depend on the pressure difference between the duct inlet 146 and the duct outlet 152. That is, in the illustrated embodiment, the duct inlet 146 and the duct outlet 152 may be located at opposite ends or along the length of the fin internal cavity 138, and may be located in different or independent fin internal cavities 138.

[0033] Furthermore, the multiple channels 153 may be arranged to extend into the casing internal cavity 111 or the multiple casing internal cavities, or to be in fluid communication with each other and to each other, as shown in Figure 4. Each of the multiple channels 153 may be configured to transfer heat generated by one or more electronic devices 113. Furthermore, in some embodiments, each of the multiple channels 153 may allow airflow to flow in and / or change its pressure in order to guide the airflow as desired. For example, the multiple channels 153 may be strategically arranged to have openings to specific points outside the casing internal cavity 111, and by changing the pressure at these openings, assist and / or cause airflow to be guided to the outside of the casing internal cavity 111, for example, through a plurality of elongated holes 148.

[0034] Each of the multiple channels 153 may have a rectangular, circular, or other cross-sectional shape, but may be any cross-sectional shape, and is not limited to these. Furthermore, in some embodiments, each of the multiple channels 153 may be formed using 3D printing technology. In other embodiments, each of the multiple channels 153 may be formed by casting, machining, or any other suitable manufacturing technique.

[0035] Thus, the pressure difference can be controlled by design. Specifically, the pressure difference for a desired airflow rate can be changed by altering the angle and / or shape of at least one fin 120a of the multiple fins 120 relative to the outer surface 124a, and / or by changing the arrangement of the duct inlet 146 and / or duct outlet 152 along the length of the fin 120a. Furthermore, the pressure difference can be controlled by adding multiple channels 153 at specific locations within the casing 110.

[0036] Next, referring to Figures 4 and 5, in operation, the exemplary two-part cooling system 126 removes heat from one or more electronic devices 113, such as a power device package 134, via an induced airflow 160 and a self-excited oscillating heat pipe assembly 130. The induced airflow 160 includes two types of airflow: a fin airflow indicated by arrow 162 and a ducted airflow indicated by arrow 164. The multiple fins 120 guide the fin airflow 162 between them, moving along the length of the internal cavity 138 of each fin 120a from one end surface 124e to the other end surface 124f.

[0037] Thus, the fin airflow 162 is determined by or influenced by the pressure generated by the multiple fins 120, and the fin airflow 162 is guided along the length of the casing 110. The duct airflow 164 may be a portion of the fin airflow 162 guided from the fin internal cavity 138 into the duct inlet 146 by the pressure difference between the casing internal cavity 111 and the outer surface 124a of the casing 110 within the fin internal cavity 138. As shown in the figure, the duct airflow 164 flows into the casing internal cavity 111 through the duct inlet 146, passing through or traversing the multiple channels 153, while passing through or contacting the multiple ribs 150 located within the casing internal cavity 111, absorbing and / or transporting the heat generated by one or more electronic devices 113. The generated heat is indicated by arrow 166 in Figure 4.

[0038] The duct airflow 164 flows out of the casing internal cavity 111 through a plurality of elongated holes 148, which are fluidly connected to a plurality of channels 153 and adjacent casing internal cavities 111. As a result, the duct airflow 164 passes through the cavities and the plurality of channels 153 and flows out of the casing 110 as a heated airflow at the duct outlet 152, as indicated by the arrow 168. The heated airflow 168 is released from the casing 110 via the fin airflow 162. It should be understood that the arrangement of the duct inlet 146 located on the high-pressure side of the fin 120a, the plurality of channels 153, and the duct outlet 152 located on the low-pressure side of the fin 120a allows the duct airflow 164 to pass through the casing 110 and remove heat 166 generated by one or more electronic devices 113 from the casing 110.

[0039] Referring next to Figure 6, the system 100 is shown on an eVTOL 172. Multiple motors 101 connected to multiple propellers 102 by multiple propeller shafts 103 may be used. The eVTOL 172 may use the lift from the multiple propellers 102 to take off and land vertically. The multiple propellers 102 may also provide thrust so that the eVTOL 172 can move forward. In addition, the airflow from the propellers 102 may provide airflow to multiple fins 120 (Figure 1) of the system 100. In an alternative embodiment, the airflow from the propellers 102 may also provide airflow to the internal cavities 138 of the fins, which can then be directed to the duct assembly 132 (Figure 4). The airflow may allow the condenser 144 to condense the coolant inside each self-excited oscillating heat pipe assembly 130, thereby cooling the electronic device 113.

[0040] System 100 may enable improved cooling of electronic equipment 113 in electric aircraft, including eVTOL 172. System 100 may include an exemplary two-part cooling system 126. The exemplary two-part cooling system 126 may be further configured by the user by selecting a desired number of multiple fins 120 (Figure 4), the angle and / or shape of each of the multiple fins 120 (Figure 4), and / or similar, in order to achieve the desired cooling capacity of the exemplary two-part cooling system 126. Each of the multiple fins 120 may be positioned in the airflow of multiple propellers 102 so that the airflow can further cool the condensed portion 144 incorporated into the casing via a duct assembly 132 (Figure 4). A self-excited oscillating heat pipe assembly 130 may enable more efficient heat transfer across the entire fin of each fin 120a (Figure 4) of the multiple fins 120 (Figure 4). This more efficient heat transfer can remove more heat from the electronic device 113, which may allow the electronic device 113 to operate more efficiently.

[0041] The two-part cooling system example described above provides a case that includes multiple heat transfer enhancing structures, such as multiple fins and channels, which are located within the cavity of the casing. Each of the multiple fins is configured to create a pressure difference, causing a pressure difference from one side to the other. A duct inlet is located on the high-pressure side of one of the multiple fins, and a duct outlet is located on the low-pressure side of one of the multiple fins, thereby allowing and guiding airflow through the cavity of the case and dissipating heat from the cavity. Furthermore, an integrated PHP structure is located within the case, which is configured to transfer heat from the power device to the multiple fins.

[0042] While specific embodiments have been described and documented herein, it should be understood that various other changes and modifications can be made without departing from the spirit and scope of the claimed subject matter. Furthermore, while various aspects of the claimed subject matter have been described herein, such aspects do not necessarily need to be used in combination. Accordingly, the appended claims are intended to encompass all such changes and modifications within the scope of the claimed subject matter.

[0043] The inventions disclosed herein may include the following embodiments: (1) A cooling system, A casing that encloses one or more electronic devices, At least two fins extending from the outer surface of the casing, each of the at least two fins configured to guide airflow to generate a high-pressure region and a low-pressure region, Equipped with, The casing includes a duct assembly having a duct inlet and a duct outlet, wherein the duct inlet is configured to be located in the high-pressure region and the duct outlet is configured to be located in the low-pressure region. Cooling system. (2) The cooling system of (1) above, wherein the casing is A cooling system further comprising an internal cavity defined by the internal surface of the casing, wherein a plurality of heat-promoting structures extend from the internal surface of the casing. (3) The cooling system of (2) above, wherein at least a portion of the one or more electronic devices is in contact with at least a portion of the inner surface of the casing. (4) The cooling system of (2) above, wherein the casing is Multiple elongated holes for guiding the aforementioned airflow, Furthermore, The plurality of elongated holes are arranged to extend through the inner surface and the opposing outer surface of the casing in order to communicate fluidly with the internal cavity and the duct outlet. Cooling system. (5) The cooling system according to (4) above, wherein each pair of at least two fins and the outer surface of the casing define a fin internal cavity, and the duct inlet and the duct outlet are located in different fin internal cavities. (6) The cooling system of (5) above, The present invention further comprises at least one self-excited oscillating heat pipe, wherein at least a portion of the at least one self-excited oscillating heat pipe is located within the internal cavity of the casing. Cooling system. (7) The cooling system according to (6) above, wherein each of the at least one self-oscillating heat pipes has a closed loop structure. (8) The cooling system according to (7) above, wherein the internal cavity of the casing is an evaporation section for the at least one self-excited oscillating heat pipe, and the internal cavity of the fin is a condensation section for the at least one self-excited oscillating heat pipe. (9) Electric motor assembly, Motor housing and The motor inside the motor housing, A casing having an outer surface and opposing inner surfaces that define the internal cavity of the casing, One or more electronic devices are disposed within the internal cavity of the casing, which is surrounded by the aforementioned internal surface. At least two fins extending from the outer surface of the casing, wherein each pair of the at least two fins and the outer surface of the casing define an internal cavity within the fins, and each of the at least two fins is configured to guide airflow to generate high-pressure and low-pressure regions, Equipped with, The casing includes a duct assembly having a duct inlet and a duct outlet, wherein the duct inlet is configured to be located in the high-pressure region and the duct outlet is configured to be located in the low-pressure region. Electric motor assembly. (10) The electric motor assembly according to (9) above, wherein the internal cavity of the casing includes a plurality of heat-promoting structures extending from the internal surface. (11) An electric motor assembly as described in (10) above, wherein the casing is Multiple elongated holes for guiding the aforementioned airflow, Furthermore, The plurality of elongated holes are arranged to extend through the internal and external surfaces in order to fluidly communicate with the internal cavity of the casing and the duct outlet. Electric motor assembly. (12) The electric motor assembly according to (11) above, wherein the duct inlet and the duct outlet are located in different finned internal cavities. (13) The electric motor assembly of the above (12), An electric motor assembly further comprising at least one self-excited oscillating heat pipe, wherein at least a portion of the at least one self-excited oscillating heat pipe is located within the internal cavity of the casing. (14) The electric motor assembly according to (13) above, wherein each of the at least one self-excited oscillating heat pipes is a closed loop structure. (15) The electric motor assembly according to (14) above, wherein the internal cavity of the casing is an evaporation section for the at least one self-excited oscillating heat pipe, and the internal cavity of the fin is a condensation section for the at least one self-excited oscillating heat pipe. (16) The electric motor assembly according to (9) above, wherein at least a portion of the one or more electronic devices is in contact with at least a portion of the internal surface. (17) An electric vertical takeoff and landing aircraft, The electric motor assembly comprises, Motor housing and The motor inside the motor housing, A casing having an external surface and opposing internal surfaces that define the internal cavity of the casing, One or more electronic devices are disposed within the internal cavity of the casing, which is surrounded by the aforementioned internal surface. At least two fins extending from the outer surface of the casing, wherein each pair of the at least two fins and the outer surface of the casing define an internal cavity within the fins, and each of the at least two fins is configured to guide airflow to generate high-pressure and low-pressure regions, Equipped with, The casing includes a duct assembly having a duct inlet and a duct outlet, wherein the duct inlet is configured to be located in the high-pressure region and the duct outlet is configured to be located in the low-pressure region. Electric vertical takeoff and landing aircraft. (18) An electric vertical takeoff and landing aircraft as described in (17) above, wherein the internal cavity of the casing includes a plurality of heat-enhancing structures extending from the internal surface, a plurality of elongated holes for guiding the airflow, and the plurality of elongated holes are arranged to extend through the internal surface and the external surface in order to fluidly communicate with the internal cavity of the casing and the duct outlet. (19) An electric vertical takeoff and landing aircraft as described in (18) above, wherein the duct inlet and the duct outlet are located in different fin-internal cavities. (20) An electric vertical takeoff and landing aircraft as described in (19) above, further comprising at least one self-excited vibrating heat pipe, wherein at least a portion of the at least one self-excited vibrating heat pipe is located within the internal cavity of the casing, and each of the at least one self-excited vibrating heat pipe is in a closed loop structure.

Claims

1. A cooling system, A casing that encloses one or more electronic devices, At least two fins extending from the outer surface of the casing, each of the at least two fins configured to guide airflow to generate a high-pressure region and a low-pressure region, Equipped with, The casing includes a duct assembly having a duct inlet and a duct outlet, wherein the duct inlet is configured to be located in the high-pressure region and the duct outlet is configured to be located in the low-pressure region. Cooling system.

2. A cooling system according to claim 1, wherein the casing is A cooling system further comprising an internal cavity defined by the internal surface of the casing, wherein a plurality of heat-promoting structures extend from the internal surface of the casing.

3. A cooling system according to claim 2, wherein at least a portion of the one or more electronic devices is in contact with at least a portion of the inner surface of the casing.

4. A cooling system according to claim 2, wherein the casing is Multiple elongated holes for guiding the aforementioned airflow, Furthermore, The plurality of elongated holes are arranged to extend through the inner surface and the opposing outer surface of the casing in order to communicate fluidly with the internal cavity and the duct outlet. Cooling system.

5. A cooling system according to claim 4, wherein each pair of at least two fins and the outer surface of the casing define a fin-internal cavity, and the duct inlet and the duct outlet are located in different fin-internal cavities.

6. A cooling system according to claim 5, The present invention further comprises at least one self-excited oscillating heat pipe, wherein at least a portion of the at least one self-excited oscillating heat pipe is located within the internal cavity of the casing. Cooling system.

7. A cooling system according to claim 6, wherein each of the at least one self-oscillating heat pipes has a closed loop structure.

8. A cooling system according to claim 7, wherein the internal cavity of the casing is an evaporation section for the at least one self-excited oscillating heat pipe, and the internal cavity of the fin is a condensation section for the at least one self-excited oscillating heat pipe.

9. An electric motor assembly, Motor housing and The motor inside the motor housing, A casing having an external surface and opposing internal surfaces that define the internal cavity of the casing, One or more electronic devices are disposed within the internal cavity of the casing, which is surrounded by the aforementioned internal surface. At least two fins extending from the outer surface of the casing, wherein each pair of the at least two fins and the outer surface of the casing define an internal cavity within the fins, and each of the at least two fins is configured to guide airflow to generate high-pressure and low-pressure regions, Equipped with, The casing includes a duct assembly having a duct inlet and a duct outlet, wherein the duct inlet is configured to be located in the high-pressure region and the duct outlet is configured to be located in the low-pressure region. Electric motor assembly.

10. An electric motor assembly according to claim 9, wherein the internal cavity of the casing includes a plurality of heat-promoting structures extending from the internal surface.

11. An electric motor assembly according to claim 10, wherein the casing is Multiple elongated holes for guiding the aforementioned airflow, Furthermore, The plurality of elongated holes are arranged to extend through the internal and external surfaces in order to fluidly communicate with the internal cavity of the casing and the duct outlet. Electric motor assembly.

12. An electric motor assembly according to claim 11, wherein the duct inlet and the duct outlet are located in different finned internal cavities.

13. An electric motor assembly according to claim 12, An electric motor assembly further comprising at least one self-excited oscillating heat pipe, wherein at least a portion of the at least one self-excited oscillating heat pipe is located within the internal cavity of the casing.

14. An electric motor assembly according to claim 13, Each of the at least one self-oscillating heat pipes has a closed loop structure. The internal cavity of the casing is an evaporation section for the at least one self-excited oscillating heat pipe, and the internal cavity of the fin is a condensation section for the at least one self-excited oscillating heat pipe. Electric motor assembly.

15. An electric motor assembly according to claim 9, wherein one or more electronic devices are in contact with at least a portion of the internal surface.

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