Integrated cooler for in-wheel motor

Abstract

To provide an integrated cooler for an in-wheel motor that belongs to a technical field of a cooling device, in which cooling work fluid is filled in an airtight container and an electronic control chip and a motor stator are adhered and mounted to different surfaces of the airtight container for cooling and in which air bubble pumps aligned on an inner wall of the airtight container is driven to transfer the cooling work fluid to a high place by using a buoyance flow generated by rising of air bubbles so as to enable extremely uniform cooling of the entire in-wheel motor.SOLUTION: An integrated cooler for an in-wheel motor includes: an airtight container disposed inside the in-wheel motor for filling cooling work fluid and having a steam outlet and a liquid return port; air bubble pumps aligned on an inner wall of the airtight container and driven to transfer the cooling work fluid to a high place of the airtight container; a motor stator arranged on an outer wall surface close to an outer side of the airtight container; and an electronic control chip that is disposed on a wall surface of the airtight container and of which arrangement position includes the cooling work fluid.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the technical field of cooling devices, and in particular to an integrated cooler for an in-wheel motor. [Background technology]

[0002] The main feature of in-wheel motor technology for new energy vehicles is the integration of the vehicle's drive motor inside the wheel, which allows for a reduction in transmission parts through integration and has many advantages, such as flexible control, high flexibility, energy savings, and space savings. However, problems such as poor heat dissipation and motor overheating due to integration are one of the major obstacles hindering the development of in-wheel motors. Cooling methods for in-wheel motors for new energy vehicles can be roughly divided into three categories: air cooling, liquid cooling, and phase change cooling.

[0003] However, existing cooling methods for in-wheel motors for new energy vehicles all have technical problems, such as poor cooling efficiency, low integration and compactness, and large device weight. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of this, we provide an integrated cooler for an in-wheel motor to solve the technical problems commonly present in in-wheel motors for new energy vehicles, such as poor cooling effect and low integration and compactness. This cooler uses an airtight container designed to fit the shape of the in-wheel motor inside the in-wheel motor to seal in the cooling working fluid, thereby achieving highly efficient cooling of the in-wheel motor (which has an electronic control chip and motor stator) by utilizing the phase change heat transfer of the cooling working fluid. The working fluid in the cooler boils, and the resulting vapor is guided to the condenser from the vapor outlet, where it is condensed into a liquid, which returns to the cooler from the liquid return port, forming a natural circulation of the working fluid. An air bubble pump arranged on the inner wall of the airtight container transports the cooling working fluid to a high altitude by utilizing the buoyancy flow generated by the rising of air bubbles, thereby enabling fairly uniform cooling of the entire in-wheel motor. Means for solving the invention

[0005] To achieve the above objectives, the present invention provides the following technical solutions: The integrated cooler for in-wheel motors is an airtight container disposed inside the in-wheel motor for enclosing a cooling working fluid, the airtight container having a vapor outlet and a liquid return port; an air bubble pump arranged on an inner wall of the airtight container for driving the cooling working fluid to transport it to a higher position in the airtight container; a motor stator arranged on an outer wall surface near the outside of the airtight container; and an electronic control chip disposed on the wall of the airtight container, the electronic control chip having the cooling working fluid at its location.

[0006] Preferably, the air bubble pump includes a first air bubble pump disposed on an inner wall surface close to the outside of the airtight container.

[0007] Preferably, the electronic control chip is arranged on the outer wall surface inside the airtight container, and the cooling working fluid is indirectly heated and boiled through the wall surface, and a highly thermally conductive metal plate is arranged on the outside of the airtight container.

[0008] Preferably, a wick for enhancing boiling heat transfer is arranged on the inside of the inner wall surface of the airtight container.

[0009] Preferably, the heat-receiving wall surface of the air bubble pump is provided with a wick, which should be a porous material with strong liquid absorption capabilities, such as a foam metal material, a sintered metal mesh, a sintered metal felt product, or other material with a micropore size, and the capillary phenomenon within the wick can be used to promote liquid supply in the height direction of the heating wall.

[0010] Preferably, a second air bubble pump is disposed on the inner wall surface of the airtight container.

[0011] Preferably, the electronic control chip and the highly thermally conductive metal plate extend to the upper center of the airtight container.

[0012] Preferably, an insertion hole for inserting the electronic control chip is formed on the airtight container, and the insertion hole is submerged in the cooling working fluid.

[0013] Preferably, the amount of the cooling working fluid filled corresponds to 30% to 70% of the height of the airtight container.

[0014] Preferably, the first air bubble pump is made up of a plurality of parallel narrow flow channels.

[0015] Preferably, both sides of the electronic control chip are coated with a thermally conductive filler. [Effects of the Invention]

[0016] The present invention has the following beneficial effects compared to the prior art. The integrated cooler for an in-wheel motor according to the present invention is designed to be compatible with the shape of the in-wheel motor and to have an airtight container for enclosing a cooling working fluid inside the in-wheel motor. This allows for highly efficient cooling using the phase change heat transfer of the cooling working fluid, and also improves the integration and compactness of the in-wheel motor (including the electronic control system) and the cooling system, thereby improving cooling performance and reducing the total weight of the system, thereby improving the overall performance of the in-wheel motor cooling system. Heat-generating elements such as the in-wheel motor electronic control chip and motor stator are installed at different locations on the outer surface of the airtight container, and perform boiling and evaporative cooling by indirectly transferring heat to the cooling working fluid through thermal conduction on the container wall. Air bubble pumps arranged on the inner wall of the airtight container use the buoyancy flow generated by the rising bubbles to drive the cooling working fluid to a high altitude, allowing for fairly uniform cooling of the entire in-wheel motor.

[0017] The integrated cooler for an in-wheel motor according to the present invention has an air bubble pump arranged on the inside of the cooler wall and combined with a porous wick, thereby realizing highly efficient transport of the cooling working fluid liquid in the anti-gravity direction, thereby further improving the cooling effect. [Brief explanation of the drawings]

[0018]

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Embodiments for Carrying Out the Invention

[0019] Next, we will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the drawings in the embodiments of the present invention. Obviously, the embodiments described in this specification are only a part of the embodiments of the present invention, not all of them. For those skilled in the art, all other embodiments obtained on the premise of not paying creative labor based on the embodiments of the present invention fall within the protection scope of the present invention.

[0020] It should be noted for clarification that in the description of the present invention, the directions and positional relationships indicated by terms such as "upper", "lower", "inner", "outer", "top / bottom", etc. are based on the directions and positional relationships shown in the drawings, and are only for the convenience of simplifying the description and explanation of the present invention. However, it does not explicitly or implicitly imply that the mentioned devices or elements must have a specific direction or must be configured and operated according to a specific direction. Therefore, it should not be understood as being limited to the present invention. Moreover, terms such as "first" and "second" are used only for the purpose of explanation and should not be understood as indicating relative importance.

[0021] It should be noted for clarification that in the description of the present invention, unless otherwise explicitly specified or limited, terms such as "attach", "arrange", "attach / to contact", "connect", etc. are understood in a broad sense, for example, as "connection". These terms mean fixed connection, detachable connection, or integral connection, or mechanical connection or electrical connection, or direct connection, indirect connection through an intermediate medium, or communication between two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0022] The present invention proposes a highly integrated and compact cooler aiming at the phase change cooling technology of in-wheel motors for new energy vehicles, and its main cooling targets include (1) electronic control chips of in-wheel motors such as IGBT chips, SiC chips, and GaN chips, and (2) motor stators. In the present invention, cooling is achieved by installing the motor stator outside the outer wall surface. The electronic control chips installed at different positions of the cooler are electrically connected to the in-wheel motor via conducting wires. The cooler is divided into two types according to the various arrangement positions of the electronic control chips. The first type is an external-mounted chip cooler (see FIGS. 1-3), and the second type is an inserted chip cooler (see FIG. 4).

[0023] FIG. 1 shows the most basic integrated cooler for in-wheel motors, while FIGS. 2-4 show further improvements to the integrated cooler for in-wheel motors based on FIG. 1.

[0024] As shown in FIG. 1, the integrated cooler for in-wheel motors according to the present invention includes an airtight container 11, a bubble pump, a cooling working fluid 113, an outer wall surface 12, an inner wall surface 13, a motor stator 3, and an electronic control chip 4.

[0025] The airtight container 11 is arranged inside the in-wheel motor 1 to enclose the cooling working fluid 113 and is connected to an external condenser via a pipeline, and has a vapor outlet 111 (connected to the condenser to introduce the vapor generated by boiling into the condenser) and a liquid return port 112 (connected to the condenser to allow the condensed liquid to return to the container 11). Among them, the airtight container 11 has strict airtightness and is usually circular.

[0026] The bubble pump is arranged on the inner wall of the airtight container 11 to drive the cooling working fluid 113 to be transported to a high place in the airtight container 11. The airtight container 11 has an outer wall surface 12 and an inner wall surface 13.

[0027] The wall surfaces where the cooling working fluid 113 comes into contact with the airtight container 11 are collectively referred to as inner wall surfaces 13 , and the wall surfaces outside the inner wall surfaces 13 are collectively referred to as outer wall surfaces 12 .

[0028] The side of the inner wall surface 13 closer to the outside is called the outer side 131 of the inner wall surface (the wall surface in contact with the cooling working fluid 113), and the side of the inner wall surface 13 closer to the inside is called the inner side 132 of the inner wall surface (the wall surface in contact with the cooling working fluid 113).

[0029] The side of the outer wall surface 12 closer to the outside is called the outer outer wall surface 121 (corresponding to the outer side 131 of the inner wall surface), and the side of the outer wall surface 12 closer to the inside is called the inner outer wall surface 122 (corresponding to the inner side 132 of the inner wall surface).

[0030] The motor stator 3 is arranged on the outer wall surface close to the outside of the airtight container 11 and is preferably attached firmly and in close contact with it.

[0031] The electronic control chip 4 is disposed on the wall of the airtight container 11, and the cooling working fluid 113 is located on the inside 132 of the inner wall corresponding to the location of the electronic control chip 4. The height of the location of the electronic control chip 4 is preferably lower than the level of the cooling working fluid to ensure indirect contact with the cooling working fluid. The electronic control chip 4 may be disposed on the outer wall 122 of the airtight container 11 or on the inside 132 of the inner wall. The airtight container 11 is annular, and in addition to the outer wall 12 and the inner wall 13 described above, it has two annular surfaces on both sides. Since the electronic control chip 4 may be disposed on both annular surfaces on both sides of the airtight container 11 in the same way, those skilled in the art can select the location of the electronic control chip 4 according to actual needs.

[0032] In the integrated cooler for an in-wheel motor according to the present invention, the cooling working fluid 113 is located below the airtight container 11 under the action of gravity, and is transported to the top of the container using an air bubble pump to induce boiling and evaporation heat transfer to the upper portion in contact with the working fluid vapor. The air bubble pump drives the cooling working fluid to be transported to a high position using a buoyancy flow caused by rising bubbles, thereby enabling the entire in-wheel motor 1 to be cooled fairly uniformly.

[0033] In the present invention, the air bubble pump includes a first air bubble pump 2, and the first air bubble pump 2 is preferably arranged on one side of the inner wall surface 13 of the airtight container, and the first air bubble pump 2 is preferably arranged on the outside 131 of the inner wall surface.

[0034] In the present invention, as shown in FIG. 1, the electronic control chip 4 is arranged on the outer wall surface 122 near the inside of the airtight container 11, and a highly thermally conductive metal plate 5 is arranged on the outside of the airtight container 11. Preferably, the highly thermally conductive metal plate 5 is made of a copper plate. In this embodiment, the electronic control chip 4 is attached to the inner outer wall surface 122 of the airtight container 11, resulting in a device called an external chip-mounted cooler. An arc-shaped copper piece of highly thermally conductive metal plate 5 is attached to the electronic control chip 4, firmly pressing it against the chip. The highly thermally conductive metal plate 5 serves two functions: (1) it applies pressure to reduce the contact thermal resistance between the electronic control chip 4 and the cooling surface, and (2) it acts as a link for heat transfer from the heat-generating surface to the cooling surface. The highly thermally conductive metal plate 5 enhances the overall heat transfer from the electronic control chip 4 to the cooler, improving the cooling effect on both surfaces of the electronic control chip 4. Preferably, the electronic control chip 4 is made into multiple rectangular pieces with side lengths of approximately 1 cm to 4 cm, and both the front and rear surfaces of the electronic control chip 4 are heated surfaces. Preferably, in order to reduce the contact thermal resistance between both surfaces of the electronic control chip 4 and the cooler and highly thermally conductive metal plate 5, a highly thermally conductive filler is filled in the gaps to promote heat conduction.

[0035] As shown in Figure 2, the present invention achieves the purpose of promoting cooling of the electronic control chip 4 by arranging a wick 6 (preferably a porous material) on the inside 132 of the inner wall surface of the airtight container 11 based on the first embodiment as a second improved embodiment for enhancing boiling heat transfer. The wick 6 has a strong liquid absorption ability, enhances boiling heat transfer, and assists the air bubble pump in transporting liquid to a high altitude (the second air bubble pump in the third improved embodiment). The wick 6 is made of a material with micropores, such as a metal foam material, a sintered metal mesh, or a sintered metal felt product.

[0036] As shown in Figure 3, in a third improved embodiment, the present invention is based on the first embodiment and provides a second bubble pump 7 on the other side of the inner wall surface 13 of the airtight container 11, supplying coolant to the upper middle portion to cool the electronic control chip mounted at a higher position. Preferably, the second bubble pump 7 has the same structure as the first bubble pump 2.

[0037] In the present invention, the second air bubble pump 7 is disposed on the other side of the inner wall surface 13 of the airtight container 11. Preferably, the second air bubble pump 7 is disposed on the inner side 132 of the inner wall surface.

[0038] In this improved embodiment, since an air bubble pump is provided on the inner wall surface, the electronic control chip 4 does not need to be arranged up to the middle and lower part of the airtight container 11, but can be attached at a higher position (above the liquid level of the filled cooling working fluid). Specifically, in the present invention, if the electronic control chip 4 and the highly thermally conductive metal plate 5 extend to the middle and upper part of the airtight container 11, it is possible to install more electronic control chips 4 on the inner outer wall surface 122 (electronic control chips 4 installed in the middle and upper part of the airtight container 11 will not have corresponding cooling fluid inside the airtight container 11 at that position).

[0039] As shown in FIGS. 4-7, as a fourth improvement aspect, in the present invention, an insertion hole 8 for inserting the electronic control chip 4 is opened in the airtight container 11 based on the first aspect. Preferably, the insertion hole 8 is in an inverted T-shape (see FIG. 7) or an L-shape (see FIG. 6). The insertion hole 8 is submerged in the cooling working fluid 113, but the position of the insertion hole 8 does not exceed the liquid level of the cooling working fluid 113 because there is a certain liquid level in the cooling working fluid 113. Accordingly, the insertion hole 8 is submerged in the cooling working fluid 113.

[0040] In the fourth improvement aspect, in order to strengthen the cooling of the heating surfaces on both sides of the electronic control chip 4, the electronic control chip 4 is not attached to the outer surface of the inner wall surface, and an elongated insertion hole 8 is opened at the bottom of the airtight container 11 and the electronic control chip 4 is inserted therein for cooling. It is not necessary to strengthen the heat transfer inside the inner wall surface with a porous body or the second bubble pump 7. The insertion hole 8 needs to be submerged in the coolant, and a heat-conductive filler is applied between the surface of the electronic control chip 4 and the surface of the insertion hole 8 to enhance heat conduction. With this structure, there is a possibility that the surfaces on both sides of the electronic control chip 4 can all perform highly efficient cooling through boiling (if necessary, a heat transfer promoter such as a porous body can be additionally installed on the inner surface to enhance boiling heat transfer).

[0041] Moreover, the inner outer wall surface 122 has the same structure as the cooler shown in FIGS. 1-3, and uses the first bubble pump 2 to achieve the supply of the coolant from the bottom to the top.

[0042] In the present invention, the filling amount of the cooling working fluid 113 corresponds to 30% to 70% of the height of the airtight container 11. The sealed container 11 discharges air from the inside by evacuation before filling. Among them, the cooling working fluid 113 may select Novec 7100 (electronic fluorine-based fluid) or water or alcohol, etc. according to the range of use temperature and pressure.

[0043] As shown in FIG. 8, in the present invention, the first bubble pump 2 is composed of a plurality of parallel narrow flow paths. Preferably, the cross-section of the flow path is rectangular.

[0044] As shown in FIG. 8, in the present invention, the second bubble pump 7 is composed of a plurality of parallel narrow flow paths.

[0045] In the present invention, preferably, the first bubble pump 2 and the second bubble pump 7 have a similar structure, and both are composed of a plurality of parallel narrow flow paths. Their cross-sectional shapes are not specified, and preferably, a square with a side length of about 1 to 3 mm is selected. The first bubble pump 2 and the second bubble pump 7 have the same radius of curvature as the wall surface corresponding to the airtight container 11 in order to be firmly attached to the heat transfer surface, and need to be firmly pressed during installation.

[0046] In the present invention, both sides of the electronic control chip 4 are coated with a heat-conductive filler to enhance heat transfer.

[0047] FIG. 9 shows an improved method for arranging the electronic control chip in the present invention. In order to ensure closer contact between the electronic control chip and the cooler wall surface, the electronic control chip can be arranged on the flat wall surface of the cooler. For example, two annular flat wall surfaces perpendicular to the outer wall surface 12 and the inner wall surface 13. In this improved method, a higher thermal conductivity metal plate is further arranged to firmly press the electronic control chip against the cooling wall. Also, the inner wall surface on which the electronic control chips are arranged can optimize the performance by using bubble pumps, wicks, etc.

[0048] The above content is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various changes and modifications to the present invention. Changes, equivalent substitutions, improvements, etc. made within the scope of the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Explanation of Reference Numerals

[0049] 1 - In - wheel motor; 11 - Hermetic container; 111 - Vapor outlet; 112 - Return liquid port; 113 - Cooling working fluid; 12 - Outer wall surface; 121 - Outer outer wall surface; 122 - Inner outer wall surface; 13 - Inner wall surface; 131 - Outside of the inner wall surface; 132 - Inside of the inner wall surface; 2 - First bubble pump; 3 - Motor stator; 4 - Electronic control chip; 5 - High - thermal - conductivity metal plate; 6 - Wick; 7 - Second bubble pump; 8 - Insertion hole

Claims

1. An airtight container disposed inside an in-wheel motor for enclosing a cooling working fluid, having a vapor outlet and a liquid return port; A bubble pump arranged on the inner wall surface of the airtight container for driving the cooling working fluid to be transported to a high position of the airtight container; A motor stator arranged on an outer wall surface close to the outside of the airtight container; An electronic control chip arranged on the wall surface of the airtight container, with the cooling working fluid at its arranged position; An integrated cooler for an in-wheel motor, characterized by the above.

2. The integrated cooler for an in-wheel motor according to Claim 1, characterized in that the bubble pump includes a first bubble pump arranged on one side of the inner wall surface of the airtight container.

3. The integrated cooler for an in-wheel motor according to Claim 2, characterized in that the first bubble pump is arranged on the other side of the inner wall surface of the airtight container.

4. The integrated cooler for an in-wheel motor according to Claim 1, characterized in that the electronic control chip is arranged on an outer wall surface close to the inside of the airtight container, and a high thermal conductivity copper plate is arranged on the outside of the airtight container.

5. The integrated cooler for an in-wheel motor according to Claim 4, characterized in that a wick for enhancing boiling heat transfer is arranged inside the inner wall surface of the airtight container.

6. The integrated cooler for an in-wheel motor according to Claim 4, characterized in that the electronic control chip and the high thermal conductivity copper plate extend up to the upper middle part of the airtight container.

7. The integrated cooler for an in-wheel motor according to Claim 1, characterized in that an insertion hole for inserting the electronic control chip is opened on the airtight container, and the insertion hole is submerged in the cooling working fluid.

8. The integrated cooler for an in-wheel motor according to Claim 1, characterized in that the filling amount of the cooling working fluid corresponds to 30% - 70% of the height of the airtight container.

9. The integrated cooler for an in-wheel motor according to Claim 1, characterized in that the first bubble pump is composed of a plurality of parallel narrow flow paths.

10. The integrated cooler for an in-wheel motor according to any one of Claims 1 - 9, characterized in that both sides of the electronic control chip are coated with a thermal conductive filler.

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