Outdoor unit of an air conditioning system

Abstract

A toroidal coil cooling structure (100) comprises a toroidal coil (10), a printed wiring board (9), a partition plate (8), thermal paste (17), a pillar (51), and a pressing plate (50). An overhang section (18b) of a winding (13) is connected to the printed wiring board (9) so as to be able to move the toroidal coil (10) in a direction in which the toroidal coil (10) overlaps the thermal paste (17). The pressing plate (50) is configured to press the toroidal coil (10) against the thermal paste (17).

Description

Technical Field

[0001] The present disclosure relates to a cooling structure for a toroidal coil and an outdoor unit of an air conditioner.

Background Art

[0002] Conventionally, a cooling structure for a toroidal coil is known. For example, Japanese Unexamined Patent Application Publication No. 2020-188131 (Patent Document 1) describes a cooling structure for a toroidal coil. In this publication, a portion located on the opening side of the coil cover in the toroidal coil is thermally connected to the housing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When winding a metal wire around a core for the winding of a toroidal coil, variations in the winding height occur depending on the winding method, start and end of winding, etc. Particularly in power electronics devices with a large operating current such as an outdoor unit of an air conditioner, a thick metal wire is used for the winding of the toroidal coil in order to suppress the temperature rise of the winding. When the metal wire is thick, the required bending pressure for plastic processing increases, and the variations become larger. Further, in a toroidal coil, the wiring ends of the winding are inserted into through-holes of a printed wiring board and fixed by soldering, and variations in the mounting height occur at this time.

[0005] In the above publication, a gap is provided between the toroidal coil and the coil cover to absorb variations in height. However, on the opposite side of the gap, the housing side, the toroidal coil is only thermally connected to a thermal conductive sheet. Since the thermal conductive sheet is thermally connected only to the outermost surface of the toroidal coil windings, the contact area is small and the thermal resistance is high.

[0006] Furthermore, to compensate for variations in the winding height and mounting height of the toroidal coil, the heat dissipation sheet must be thick. Typical heat dissipation sheets are composed of flexible resin and thermally conductive filler, but there is a limit to the dimensions that can be compressed, and it is generally said that the compressible dimensions are around 30%. For example, a heat dissipation sheet with a thickness of 1 mm can be compressed by about 0.3 mm, so if the variation is 1 mm, a heat dissipation sheet with a thickness of about 3 mm is required. Thermal resistance is inversely proportional to the contact area and thermal conductivity and is proportional to the thickness, so the thermal resistance increases further as the thickness increases.

[0007] This disclosure has been made in view of the above-mentioned problems, and its purpose is to provide a cooling structure for a toroidal coil that can absorb winding and fixing variations of the toroidal coil, realize a thermal connection with an increased contact area, and dissipate heat with low thermal resistance, as well as an outdoor unit of an air conditioning system equipped therewith. [Means for solving the problem]

[0008] The cooling structure for a toroidal coil of this disclosure comprises a toroidal coil, a printed circuit board, a metal housing, thermal grease, a column, and a retaining plate. The toroidal coil includes a core and windings wound around the core. The printed circuit board, on which the toroidal coil is mounted, includes a front and a back surface. The metal housing is positioned on the opposite side of the front surface to the back surface of the printed circuit board. Thermal grease is positioned between the toroidal coil and the metal housing. The column is supported by the metal housing. The retaining plate is connected to the column and clamps the toroidal coil between itself and the metal housing. The windings include overhangs that extend from the core and along the surface of the printed circuit board. The overhangs of the windings are connected to the printed circuit board so that the toroidal coil is movable in a direction that overlaps the thermal grease. The retaining plate is configured to press the toroidal coil against the thermal grease. [Effects of the Invention]

[0009] The cooling structure for the toroidal coil of this disclosure absorbs winding and fixing variations of the toroidal coil, achieves a thermal connection with an enlarged contact area, and enables heat dissipation with low thermal resistance. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the outdoor unit of the air conditioning system according to Embodiment 1, viewed from the front. [Figure 2] This is a schematic diagram showing the outdoor unit of the air conditioning system according to Embodiment 1, viewed from the plan side. [Figure 3] Figure 3A is a schematic top view and Figure 3B is a schematic side view of a toroidal coil according to Embodiment 1. [Figure 4] This is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to Embodiment 1. [Figure 5] This is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to Embodiment 2. [Figure 6] This is a schematic cross-sectional view showing the cooling structure of a toroidal coil according to Embodiment 3. [Figure 7] It is a schematic cross-sectional view showing the cooling structure of the toroidal coil according to Embodiment 4. [Figure 8] It is a schematic cross-sectional view showing the cooling structure of the toroidal coil according to Embodiment 5. [Figure 9] FIG. 9A is a schematic top view and FIG. 9B is a schematic side view of the toroidal coil according to Embodiment 5. [Figure 10] It is a schematic cross-sectional view showing the cooling structure of the toroidal coil according to Embodiment 6. [Figure 11] It is a schematic plan view showing the cooling structure of the toroidal coil according to Embodiment 6. [Figure 12] FIG. 12A is a schematic top view and FIG. 12B is a schematic side view of the toroidal coil according to Embodiment 7. [Figure 13] FIG. 13A is a schematic top view and FIG. 13B is a schematic side view of the toroidal coil according to Embodiment 7. [Figure 14] It is a schematic cross-sectional view showing the cooling structure of the toroidal coil according to Embodiment 8. [Figure 15] It is a schematic cross-sectional view showing the leaf spring before fixing the toroidal coil according to Embodiment 8. [Figure 16] It is a schematic perspective view showing the leaf spring of the cooling structure of the toroidal coil according to Embodiment 8.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0012] Embodiment 1. First, the configuration of the outdoor unit 1 of the air conditioner according to Embodiment 1 will be described. FIG. 1 is a schematic view showing the outdoor unit 1 of the air conditioner according to Embodiment 1 from the front side. FIG. 2 is a schematic view showing the outdoor unit 1 of the air conditioner according to Embodiment 1 from the plane side.

[0013] Referring to FIGS. 1 and 2, the outdoor unit 1 of the air conditioner according to this embodiment incorporates a compressor 2, a heat exchanger 3, a board mounting plate 4, an outdoor unit fan 5, etc. The outdoor unit 1 of the air conditioner includes a cooling structure 100 for a toroidal coil 10. The outdoor unit 1 includes a blower chamber 7 where an outdoor unit fan 5 for blowing air is disposed, a machine chamber 6 where a printed wiring board 9 is disposed, and a partition plate 8 that separates the blower chamber 7 and the machine chamber 6. The outdoor unit 1 is divided into the machine chamber 6 and the blower chamber 7 by the partition plate 8. The compressor 2 and the board mounting plate 4 are disposed in the machine chamber 6. The heat exchanger 3 and the outdoor unit fan 5 are disposed in the blower chamber 7. The partition plate 8 is configured such that water droplets hardly penetrate from the blower chamber 7 into the machine chamber 6. The partition plate 8 is made of a metal plate having heat conductivity or the like.

[0014] The compressor 2 is disposed at the lower part of the machine chamber 6. The board mounting plate 4 is disposed at the upper part of the machine chamber 6. The heat exchanger 3 is disposed along the back surface and the side surface of the outdoor unit 1. The outdoor unit fan 5 is disposed on the front side of the outdoor unit 1 rather than the heat exchanger 3. By rotating the outdoor unit fan 5, heat exchanger air 40 flows through the heat exchanger 3, and the heat exchanger air 40 is discharged from the front of the outdoor unit 1. The heat exchanger air 40 flows along the surface of the partition plate 8 on the blower chamber 7 side. Therefore, the partition plate 8 is cooled by heat transfer due to the heat exchanger air 40.

[0015] FIG. 3 is a schematic top view of the toroidal coil 10 according to Embodiment 1 (FIG. 3A) and a schematic side view (FIG. 3B). FIG. 4 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 1.

[0016] Referring to FIGS. 3 and 4, the configuration of the cooling structure 100 of the toroidal coil 10 according to Embodiment 1 will be described.

[0017] The cooling structure 100 of the toroidal coil 10 according to Embodiment 1 includes the toroidal coil 10, a printed wiring board 9, a partition plate 8, a heat dissipation grease 17, a column 51, and a pressing plate 50. The partition plate 8 is a metal housing C.

[0018] The toroidal coil 10 has a core 11, a core case 12, windings 13, and an insulating partition plate 14. The core 11 is made of a magnetic material. The core 11 has a donut shape. The core case 12 houses the core 11. The core case 12 is made of an insulating material such as resin. The core case 12 has a shape that covers the core 11. The windings 13 are made of enameled wire, which is metal wiring such as copper covered with enamel. The windings 13 are wound around the core 11. The windings 13 are wound around the core case 12 to satisfy the required inductance value. The insulating partition plate 14 is made of an insulating material such as resin, similar to the core case 12. The insulating partition plate 14 is positioned to separate windings 13 with different potentials so that a short circuit does not occur between windings with different potentials. The insulating partition plate 14 holds the core 11. The core case 12 and the insulating partition plate 14 are either integrated or assembled together. The winding 13 of the toroidal coil 10 includes an overhang 18b. The overhang 18b extends from the core 11 and along the surface FS of the printed circuit board 9. The overhang 18b extends horizontally outward from the toroidal coil 10. The wiring end 18a of the winding 13 of the toroidal coil 10 is connected to a crimp terminal 19. The crimp terminal 19 has a configuration that allows it to be fastened with a screw, such as a ring crimp terminal or a Y-type crimp terminal.

[0019] A toroidal coil 10 is mounted on a printed circuit board 9. The printed circuit board 9 includes a front surface FS and a back surface RS. The printed circuit board 9 has an opening 9a that is larger than the dimensions of the toroidal coil 10 so that the toroidal coil 10 can pass through. Because the toroidal coil 10 is positioned within the opening 9a, the toroidal coil 10 does not interfere with the printed circuit board 9. The wiring end 18a of the toroidal coil 10 is joined to a crimp terminal 19. The wiring end 18a of the toroidal coil 10 is electrically connected to a terminal block 21 mounted on the printed circuit board 9 via a screw 22 through the crimp terminal 19. The overhang 18b of the winding 13 is connected to the printed circuit board 9 so that the toroidal coil 10 can move in a direction that overlaps the thermal grease 17. Because the overhang 18b is made of elastic metal, the toroidal coil 10 is movable in the vertical direction and has a structure that can absorb variations in height.

[0020] Although an example is described in which the printed circuit board 9 and the toroidal coil 10 are connected by crimp terminals 19, terminal block 21, and screws 22, the same effect can be obtained even if the wiring end 18a of the toroidal coil 10 is directly joined to the printed circuit board 9 by soldering or the like.

[0021] The circuit board mounting plate 4 is connected to and fixed to the outer panel of the outdoor unit 1's casing via a support member. A printed circuit board 9, on which electronic components such as power semiconductors are mounted, is placed on the circuit board mounting plate 4, and the printed circuit board 9 is fixed with screws, resin spacers, etc. The circuit board mounting plate 4 has an opening 4a on the partition plate 8 side so that the power semiconductors and toroidal coils 10 can be thermally connected to the partition plate 8. The opening 4a is larger than the dimensions of the power semiconductors and toroidal coils 10 so that they can pass through.

[0022] The toroidal coil 10 is thermally connected to the partition plate 8 by passing through the opening 9a of the printed circuit board 9 and the opening 4a of the substrate mounting plate 4. The partition plate 8 is positioned on the side opposite the front surface FS to the back surface RS of the printed circuit board 9. Thermal grease 17 is placed between the toroidal coil 10 and the partition plate 8. The thermal grease 17 only needs to have a viscosity that can hold the toroidal coil 10. Both hardened thermal grease and non-hardened thermal grease can be used as thermal grease 17. In this embodiment, hardened thermal grease is used as an example of thermal grease 17. Thermal grease 17 can be hardened after a certain period of time has elapsed since application, or hardened by ultraviolet light, etc. The thermal grease 17 is applied to the gap between the toroidal coil 10 and the partition plate 8 in its pre-hardened state. Since the thermal grease 17 is gel-like before hardening, it can be applied to the windings 13 and the core case 12 circumferentially, regardless of variations in the height of the windings 13 of the toroidal coil 10. This makes it possible to increase the contact heat dissipation area. The toroidal coil 10 and the partition plate 8 are fixed together as the thermal grease 17 hardens. The heat from the toroidal coil 10 is transferred to the partition plate 8 via the thermal grease 17. The heat conducted to the partition plate 8 is dissipated into the blower room 7 by the airflow from the outdoor unit fan 5.

[0023] The retaining plate 50 sandwiches the toroidal coil 10 between the partition plate 8. The retaining plate 50 is configured to press the toroidal coil 10 against the heat dissipation grease 17. The retaining plate 50, made of an elastic material, presses the toroidal coil 10 against the partition plate 8. The shape of the retaining plate 50 can be square, circular, etc. The retaining plate 50 is sized to cover the toroidal coil 10.

[0024] The column 51 is supported by the partition plate 8. The retaining plate 50 has screw fixing holes at positions corresponding to the column 51. The retaining plate 50 is connected to the column 51. Specifically, the retaining plate 50 is fixed to the column 51 by retaining screws 52. In Figure 4, there are two columns 51, but if the retaining plate 50 is rectangular, there may be four columns 51 placed at the four corners of the retaining plate 50, or two columns on opposite corners, or three columns 51 arranged to form a triangle. The column 51 is fixed to the partition plate 8 by screw fixing, welding, adhesive, etc. The height of the column 51 is designed to be lower than the combined height of the toroidal coil 10 and the heat dissipation grease 17. Therefore, when the retaining plate 50 is fixed to the column 51, the elastic retaining plate 50 receives a force that deforms it into an upward convex shape, pressing the toroidal coil 10 towards the partition plate 8. When the toroidal coil 10 is pressed against the partition plate 8, the thermal grease 17 between the toroidal coil 10 and the partition plate 8 is compressed. This reduces the thickness of the thermal grease 17, increases the contact pressure, and makes it possible to keep the thermal resistance low.

[0025] The displacement δ of the retaining plate 50 and the Young's modulus E of the retaining plate 50 are selected such that the pressing force is less than the allowable compressive force FC of the toroidal coil 10, and greater than the compressive force FA required to keep the thermal resistance low.

[0026] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 1, the protruding portion 18b of the winding 13 is connected to the printed circuit board 9 so that the toroidal coil 10 can move in a direction in which it overlaps with the thermal grease 17. Therefore, the elasticity of the protruding portion 18b of the winding 13 can absorb variations in the winding and fixing of the toroidal coil 10. The thermal grease 17 is placed between the toroidal coil 10 and the partition plate 8. By applying the thermal grease 17 between the toroidal coil 10 and the partition plate 8 in an unhardened state, the contact area with the toroidal coil 10 can be increased. The retaining plate 50 is configured to press the toroidal coil 10 against the thermal grease 17. Therefore, the thickness of the thermal grease 17 can be reduced by compressing the thermal grease 17 placed between the toroidal coil 10 and the partition plate 8. Thus, heat can be dissipated with low thermal resistance by the thermal grease 17.

[0027] Furthermore, the retaining plate 50 presses the toroidal coil 10 against the thermal grease 17 by elastic pressure. Therefore, even if momentary separation of the thermal grease 17 between the toroidal coil 10 and the partition plate 8 occurs due to vibration or the like, the contact pressure can be restored, allowing the system to return to a low thermal resistance state.

[0028] By filling the gap between the windings 13 of the toroidal coil 10 and the partition plate 8 with a general-purpose thermal grease 17 that possesses both high thermal conductivity and insulating properties, both insulation and heat dissipation can be achieved. Before hardening, the thermal grease 17 is in a gel-like state, which not only absorbs variations in the height of the windings 13 but also allows it to make contact with the windings 13 circumferentially. This increases the contact area and improves thermal conductivity to the partition plate 8. Once the thermal grease 17 hardens, the partition plate 8 and the toroidal coil 10 can be fixed in place.

[0029] The configuration of the toroidal coil 10 allows for heat dissipation from the windings 13, and the improved heat conduction efficiency due to the thermal grease 17 prevents the temperature of the windings 13 from rising easily. Therefore, current can be carried by a coil of conventional dimensions. Alternatively, the coil windings can be made thinner, allowing for a smaller coil size. Furthermore, the enamel wire of the windings 13 can be replaced with a less expensive and more convenient wire with a lower heat resistance class.

[0030] The outdoor unit 1 of the air conditioner according to Embodiment 1 is equipped with a cooling structure 100 for the toroidal coil 10. The heat from the windings 13 of the toroidal coil 10 is conducted to the partition plate 8 via the heat dissipation grease 17. The heat is then transferred from the partition plate 8 to the heat exchanger airflow 40. In this way, the heat can be dissipated to the outside of the outdoor unit 1 via the heat exchanger airflow 40.

[0031] Embodiment 2. Figure 5 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 2.

[0032] Referring to Figure 5, the cooling structure 100 for the toroidal coil 10 according to Embodiment 2 includes a heat sink 23 and a thermal conductive sheet 24 (first thermal conductive sheet 24a).

[0033] Between the toroidal coil 10 and the partition plate 8, a thermal grease 17, a heat sink 23, and a first thermal conductive sheet 24a are arranged. The heat sink 23 is sandwiched between the thermal grease 17 and the first thermal conductive sheet 24a. The first thermal conductive sheet 24a is sandwiched between the heat sink 23 and the partition plate 8. The heat sink 23 is a metal plate with high thermal conductivity, such as aluminum or copper. The thermal conductive sheet 24 is composed of a flexible resin and a thermally conductive filler. The thermal grease 17 is applied to the gap between the toroidal coil 10 and the heat sink 23 in its uncured state. As the thermal grease 17 hardens, the toroidal coil 10 and the heat sink 23 are fixed in place. The heat from the toroidal coil 10 is transferred to the heat sink 23 via the thermal grease 17. The heat transferred to the heat sink 23, which is a metallic plate with high thermal conductivity, diffuses in the area direction (in-plane direction) of the heat sink 23. The heat that has diffused uniformly in the area direction of the heat sink 23 is then transferred perpendicularly to the partition plate 8 by the thermal conductive sheet 24.

[0034] The height of the column 51 is designed to be lower than the combined height of the toroidal coil 10, thermal grease 17, heat sink 23, and thermal conductive sheet 24. Therefore, when the retaining plate 50 is fixed to the column 51, the toroidal coil 10 is pressed against the partition plate 8 by the reaction force of the elastic retaining plate 50. This pressure on the toroidal coil 10 compresses the thermal conductive sheet 24 and the thermal grease 17 between the toroidal coil 10 and the heat sink 23. As a result, the thickness of the thermal conductive sheet 24 and the thermal grease 17 is reduced, the contact pressure increases, and the thermal resistance can be kept low.

[0035] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 2, the heat sink 23 is sandwiched between the thermal grease 17 and the first thermal conductive sheet 24a. The first thermal conductive sheet 24a is sandwiched between the heat sink 23 and the partition plate 8. As a result, the heat from the toroidal coil 10 can be transferred to the partition plate 8 via the thermal grease 17, the heat sink 23, and the first thermal conductive sheet 24a. This improves heat transfer efficiency.

[0036] Embodiment 3. Figure 6 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 3.

[0037] Referring to Figure 6, the cooling structure 100 for the toroidal coil 10 according to Embodiment 3 includes a second thermal conductive sheet 24b. The second thermal conductive sheet 24b is sandwiched between the retaining plate 50 and the toroidal coil 10. Due to the repulsive force of the second thermal conductive sheet 24b, the toroidal coil 10 is pressed against the thermal grease 17. A second thermal conductive sheet 24b is also placed on top of the toroidal coil 10 to press it towards the partition plate 8. A retaining plate 50 made of a metal such as aluminum or copper presses down on the second thermal conductive sheet 24b. The height of the column 51 is designed to be lower than the sum of the heights of the second thermal conductive sheet 24b, the toroidal coil 10, the thermal grease 17, the heat sink 23, and the first thermal conductive sheet 24a. Therefore, when the retaining plate 50 is fixed to the column 51, the toroidal coil 10 is pressed against the partition plate 8 by the reaction force of the first thermal conductive sheet 24a and the second thermal conductive sheet 24b expanding from their contracted state. As the toroidal coil 10 is pressed, the first thermal conductive sheet 24a, the second thermal conductive sheet 24b, and the thermal grease 17 between the toroidal coil 10 and the heat sink 23 are compressed. As a result, the thickness of the first thermal conductive sheet 24a, the second thermal conductive sheet 24b, and the thermal grease 17 is reduced, the contact pressure increases, and it becomes possible to keep the thermal resistance low.

[0038] Furthermore, in this structure, heat is dissipated not only on the partition plate 8 side but also on the retaining plate 50 side via the second heat conductive sheet 24b. To further increase heat dissipation on the retaining plate 50 side, heat dissipation fins (not shown) may be added to the retaining plate 50. In this embodiment, heat can be dissipated from both the retaining plate 50 side and the partition plate 8 side.

[0039] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 3, the second thermal conductive sheet 24b is sandwiched between the retaining plate 50 and the toroidal coil 10. The toroidal coil 10 is pressed against the thermal grease 17 by the repulsive force of the second thermal conductive sheet 24b. As a result, the thermal grease 17 is compressed by the repulsive force of the second thermal conductive sheet 24b, making it possible to reduce the thickness of the thermal grease 17. Therefore, heat can be dissipated with low thermal resistance by the thermal grease 17.

[0040] Furthermore, the heat generated in the winding 13 of the toroidal coil 10 can be dissipated not only on the partition plate 8 side but also on the retaining plate 50 side via the second heat conductive sheet 24b.

[0041] Embodiment 4. Figure 7 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 4.

[0042] Referring to Figure 7, the cooling structure 100 for the toroidal coil 10 according to Embodiment 4 includes a spring-loaded screw 53. The spring-loaded screw 53 includes a spring 53a. The spring-loaded screw 53 also includes a screw body 53b that expands and contracts the spring 53a. A retaining plate 50 is placed on top of the toroidal coil 10 to press the toroidal coil 10 against the partition plate 8. The retaining plate 50 may be made of resin, or of a metal such as aluminum or copper. The retaining plate 50 has a hole for fixing the spring-loaded screw. The screw body 53b is fixed to the hole for fixing the spring-loaded screw. With the screw body 53b fixed to the hole for fixing the spring-loaded screw, the spring 53a is configured to bias the retaining plate 50.

[0043] The retaining plate 50 is held to the column 51 by a spring-loaded screw 53. The repulsive force of the spring 53a of the spring-loaded screw 53 presses the retaining plate 50 against the toroidal coil 10. The repulsive force of the spring 53a of the spring-loaded screw 53 pushes the retaining plate 50 towards the partition plate 8. As a result, the toroidal coil 10 is pushed down towards the partition plate 8.

[0044] The height of the column 51 is designed to be lower than the combined height of the toroidal coil 10, thermal grease 17, heat sink 23, and thermal conductive sheet 24, so that the spring 53a of the spring-loaded screw 53 is compressed to apply the appropriate compressive force to the toroidal coil. The repulsive force of the spring 53a pushes down the retaining plate 50. This presses the toroidal coil 10 against the partition plate 8.

[0045] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 4, the retaining plate 50 is pressed against the toroidal coil 10 by the repulsive force of the spring 53a of the spring-loaded screw 53. As a result, the thermal grease 17 placed between the toroidal coil 10 and the partition plate 8 is compressed, making it possible to reduce the thickness of the thermal grease 17. Therefore, heat can be dissipated with low thermal resistance by the thermal grease 17.

[0046] Furthermore, even if momentary delamination of the heat dissipation grease 17 between the toroidal coil 10 and the partition plate 8 occurs due to vibration or other factors, the contact pressure is restored by the repulsive force of the spring 53a of the spring-loaded screw 53, making it possible to return to a low thermal resistance state.

[0047] Embodiment 5. Figure 8 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 5. Figure 9 is a schematic top view (Figure 9A) and a schematic side view (Figure 9B) of the toroidal coil 10 according to Embodiment 5.

[0048] Referring to Figures 8 and 9, a through-hole H is provided in the center of the toroidal coil 10 in a plan view. The column 51 is inserted into the through-hole H. Only one column 51 is fixed to the center of the toroidal coil 10. In order to erect the column 51 in the center of the toroidal coil 10, the insulating partition plate 14 has a hole in the center that is sized to accommodate the column 51.

[0049] The windings 13 of the toroidal coil 10 are covered with enamel to ensure insulation. However, if pinholes or cracks occur in the enamel coating during manufacturing or processing, dielectric breakdown will occur. Therefore, if the column 51 is located around the toroidal coil 10, there is a possibility of a short circuit between the windings 13 and the column 51. In this embodiment, since the column 51 is located in the center, there is no possibility of the column 51 coming into contact with the protruding portion 18b.

[0050] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 5, a through hole H is provided in the center of the toroidal coil 10 in a plan view. The column 51 is inserted into the through hole H. Therefore, the column 51 can be prevented from contacting the protruding portion 18b of the winding 13.

[0051] Embodiment 6. Figure 10 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 6. Figure 11 is a schematic plan view showing the cooling structure 100 of the toroidal coil according to Embodiment 6.

[0052] Referring to Figure 10, in the cooling structure 100 for the toroidal coil 10 according to Embodiment 6, there are no openings in the printed circuit board 9 and the substrate mounting plate 4. The toroidal coil 10 is thermally connected to the partition plate 8.

[0053] Referring to Figure 11, the retaining plate 50 is circular and sized to cover the toroidal coil 10, but it may be smaller than the toroidal coil 10. Only one column 51 is fixed to the center of the toroidal coil 10.

[0054] Referring to Figures 10 and 11, the toroidal coil 10 is positioned outside the outer edge of the printed circuit board 9. In other words, the toroidal coil 10 is placed laterally, away from the printed circuit board 9. Therefore, no opening is required in the printed circuit board 9, and the area of ​​the printed circuit board 9 can be reduced.

[0055] Next, the effects and advantages of this embodiment will be described. In Embodiment 6, the toroidal coil 10 is positioned outside the outer edge of the printed circuit board 9. Therefore, since no opening is required in the printed circuit board 9, the area of ​​the printed circuit board 9 can be reduced compared to when there is an opening in the printed circuit board 9.

[0056] Embodiment 7. Figure 12 shows a schematic top view (Figure 12A) and a schematic side view (Figure 12B) of the toroidal coil 10 according to Embodiment 7.

[0057] In Figure 12, the toroidal coil 10 has a configuration that is larger than the winding 13 in the direction in which the core case 12 is positioned on the partition plate 8. The toroidal coil 10 includes a projection 15 that protrudes toward the partition plate 8. The projection 15 is supported by the partition plate 8 so that the winding 13 is away from the partition plate 8. The projection 15 is provided in a location where there is no winding 13. The projection 15 is made of an insulating material. Specifically, the projection 15 is made of an insulating material such as resin, similar to the core case 12. The core case 12 has the projection 15. The projection 15 is positioned so that when the toroidal coil 10 comes into contact with the partition plate 8, the core case 12 does not tilt, preventing the winding 13 from coming into contact with the partition plate 8. For example, as shown in Figure 12, two projections 15 may be provided diagonally opposite each other on the core case 12, and the projections 15 may come into contact with the partition plate 8. If the winding 13 and the partition plate 8 do not come into contact, the same effect can be obtained regardless of the shape and number of protrusions 15.

[0058] Next, a modified example of the cooling structure 100 for the toroidal coil 10 according to Embodiment 7 will be described.

[0059] Figure 13 is a schematic top view (Figure 13A) and a schematic side view (Figure 13B) of the toroidal coil 10 according to Embodiment 7.

[0060] In Figure 13, the toroidal coil 10 has a configuration in which the insulating partition plate 14 is larger than the winding 13 in the direction in which the partition plate 8 is positioned. The insulating partition plate 14 has a protrusion 15. The insulating partition plate 14 has a shape such that when the toroidal coil 10 comes into contact with the partition plate 8, the core case 12 tilts or otherwise prevents the winding 13 from coming into contact with the partition plate 8. As an example, as shown in Figure 13, a cross-shaped insulating partition plate 14 may be made to protrude beyond the winding 13, and the protrusion 15 of the insulating partition plate 14 may come into contact with the partition plate 8. As long as the winding 13 and the partition plate 8 do not come into contact, the shape of the protrusion 15 of the insulating partition plate 14 does not matter, and the same effect can be obtained.

[0061] The device may be provided with not only one of the protruding portions 15 shown in Figure 12 and Figure 13, but both protruding portions 15.

[0062] The winding 13 and the partition plate 8 are connected by thermal grease 17. Because typical thermal grease 17 has both high thermal conductivity and insulating properties, the winding 13 and the partition plate 8 are thermally connected via the thermal grease 17, but not electrically connected.

[0063] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 7, the protruding portion 15 of the toroidal coil 10 is supported by the partition plate 8 such that the winding 13 is separated from the partition plate 8, and is made of an insulating material. When the protruding portion 15 comes into contact with the partition plate 8, which is made of a metal plate or the like, a gap is created between the winding 13 and the partition plate 8, thereby insulating the winding 13 from the partition plate 8. This gap ensures insulation even if pinholes or cracks occur in the enamel coating of the winding 13.

[0064] The protrusions 15 of the core case 12 and the protrusions 15 of the insulating partition plate 14 are made of insulating material. Insulating materials such as resin can generally be manufactured with smaller dimensional variations compared to the variations in the windings 13. Therefore, the positional accuracy of the partition plate 8 and the toroidal coil 10 can be improved.

[0065] According to the cooling structure 100 for the toroidal coil 10 of Embodiment 7, the core case 12 has a protrusion 15. Therefore, the core case 12 can be provided with a protrusion 15. In addition, the protrusion 15 of the core case 12 can insulate the winding 13 from the partition plate 8.

[0066] According to a modified example of the cooling structure 100 for the toroidal coil 10 in Embodiment 7, the insulating partition plate 14 has a protrusion 15. Therefore, the insulating partition plate 14 can be provided with a protrusion 15. In addition, the protrusion 15 of the insulating partition plate 14 can insulate the winding 13 from the partition plate 8.

[0067] Embodiment 8. Figure 14 is a schematic cross-sectional view showing the cooling structure 100 of the toroidal coil 10 according to Embodiment 8.

[0068] Referring to Figure 14, the cooling structure 100 for the toroidal coil 10 according to Embodiment 8 includes a leaf spring 54. The leaf spring 54 is fixed to the partition plate 8. The leaf spring 54 is made of an elastic metal, and its legs 54a are fixed to the partition plate 8 by spot welding or the like. The shape of the leaf spring 54 in Figure 14 is not necessary as long as the shape of the leaf spring 54 generates a force that presses the toroidal coil 10 toward the partition plate 8 when it deforms.

[0069] Figure 15 shows an example of the state of the leaf spring 54 before the toroidal coil 10 is fixed in Embodiment 8. In this state, the leaf spring 54 is fixed to the partition plate 8 before the toroidal coil 10, heat dissipation grease 17, etc. are fixed. The leaf spring 54 is not yet deformed, and no force is applied to it. The leaf spring 54 is housed in the opening 4a of the substrate mounting plate 4 and the opening 9a of the printed wiring board 9. The leaf spring 54 is opened by bending in the direction of the arrow in Figure 15, and after the toroidal coil 10, heat dissipation grease 17, etc. are housed inside, the bending force is released, and the toroidal coil 10 is pressed against the partition plate 8 by the elastic force of the leaf spring 54.

[0070] Figure 16 shows a perspective view of an example of a leaf spring 54. As shown in Figures 14 to 16, an example of a leaf spring 54 has a straight section extending in a straight line from the leg 54a and a curved section protruding inward from the straight section.

[0071] Next, the effects and advantages of this embodiment will be described. According to the cooling structure 100 for the toroidal coil 10 of Embodiment 8, the toroidal coil 10 is pressed against the partition plate 8 by the elastic force of the leaf spring 54. As a result, the heat dissipation grease 17 placed between the toroidal coil 10 and the partition plate 8 is compressed, making it possible to reduce the thickness of the heat dissipation grease 17. Therefore, heat can be dissipated with low thermal resistance by the heat dissipation grease 17.

[0072] Furthermore, the toroidal coil 10 is pressed against the partition plate 8 by the elastic force of the leaf spring 54. Therefore, even if momentary delamination of the heat dissipation grease 17 occurs between the toroidal coil 10 and the partition plate 8 due to vibration or other reasons, the contact pressure can be restored, allowing the system to return to a low thermal resistance state.

[0073] Furthermore, compared to previous embodiments, the only component used for pressing is the leaf spring 54, making it the easiest to manufacture.

[0074] Furthermore, since the leaf spring 54 is made of metal, it also functions as a heat sink, dissipating heat from the toroidal coil 10 into the air to reduce its temperature.

[0075] The above embodiments and variations can be combined as appropriate. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims and not by the foregoing description, and all modifications within the meaning and scope of equivalents of the claims are intended.

[0076] The various forms of this disclosure are summarized below as an appendix. (Note 1) A toroidal coil including a core and a winding wound around the core, The toroidal coil is mounted on a printed circuit board including its front and back surfaces, A metal housing is positioned on the opposite side of the front surface to the back surface of the printed circuit board, A heat dissipation grease is placed between the toroidal coil and the metal housing, A column supported by the aforementioned metal housing, It is connected to the column and comprises a retaining plate that sandwiches the toroidal coil between the metal housing, The winding includes an overhang that extends from the core and along the surface of the printed circuit board, The protruding portion of the winding is connected to the printed circuit board so that the toroidal coil can move in a direction in which the toroidal coil overlaps the heat dissipation grease. The aforementioned retaining plate is configured to press the toroidal coil against the heat dissipation grease, thereby providing a cooling structure for a toroidal coil.

[0077] (Note 2) Further comprising a heat sink and a first thermal conductive sheet, The heat sink is sandwiched between the thermal grease and the first thermal conductive sheet. The first thermal conductive sheet is sandwiched between the heat sink and the metal housing in the cooling structure for the toroidal coil described in Appendix 1.

[0078] (Note 3) Further equipped with a second heat conductive sheet, The second heat conductive sheet is sandwiched between the retaining plate and the toroidal coil. The cooling structure for a toroidal coil as described in Appendix 2, wherein the toroidal coil is pressed against the heat dissipation grease by the repulsive force of the second heat conductive sheet.

[0079] (Note 4) It also features a spring-loaded screw, The retaining plate is held to the column by the spring-loaded screw, The aforementioned spring-loaded screw includes the spring, The cooling structure for a toroidal coil according to any one of the appendices 1 to 3, wherein the retaining plate is pressed against the toroidal coil by the repulsive force of the spring.

[0080] (Note 5) In a plan view, a through hole is provided in the center of the toroidal coil. The column is inserted into the through hole, a cooling structure for a toroidal coil as described in any one of Appendix 1 to 4.

[0081] (Note 6) The toroidal coil cooling structure according to any one of the appendices 1 to 5, wherein the toroidal coil is positioned outside the outer edge of the printed circuit board.

[0082] (Note 7) The toroidal coil includes a projection that protrudes toward the metal housing, The cooling structure for a toroidal coil according to any one of the appendices 1 to 6, wherein the protruding portion is supported by the metal housing such that the winding is separated from the metal housing and is made of an insulating material.

[0083] (Note 8) The toroidal coil includes a core case that houses the core, The core case has the protruding portion, and is a cooling structure for a toroidal coil as described in Appendix 7.

[0084] (Note 9) The toroidal coil includes an insulating partition plate that holds the core, The insulating partition plate has the protruding portion, wherein this is the cooling structure for the toroidal coil as described in Appendix 7.

[0085] (Note 10) It also has a leaf spring, The leaf spring is fixed to the metal housing, The cooling structure for a toroidal coil as described in Appendix 1, wherein the toroidal coil is pressed against the metal housing side by the elastic force of the leaf spring.

[0086] (Note 11) An outdoor unit of an air conditioning system equipped with a toroidal coil cooling structure as described in any one of the appendices 1 to 10, The outdoor unit comprises a fan room in which an outdoor unit fan for blowing air is located, a machine room in which the printed circuit board is located, and a partition plate separating the fan room and the machine room. The partition plate of the outdoor unit is the metal housing of the outdoor unit of the air conditioning system. [Explanation of Symbols]

[0087] 1 Outdoor unit, 2 Compressor, 3 Heat exchanger, 4 Circuit board mounting plate, 5 Outdoor unit fan, 6 Machine room, 7 Blower room, 8 Partition plate, 9 Printed circuit board, 10 Toroidal coil, 11 Core, 12 Core case, 13 Winding, 14 Insulating partition plate, 15 Protrusion, 17 Thermal grease, 18a Wiring terminal, 18b Overhang, 19 Crimp terminal, 21 Terminal block, 23 Heat sink, 24a First thermal conductive sheet, 24b Second thermal conductive sheet, 50 Retaining plate, 51 Column, 53 Spring screw, 53a Spring, 54 Leaf spring, 100 Toroidal coil cooling structure, FS Front surface, H Through hole, RS Back surface.

Claims

1. An outdoor unit of an air conditioning system equipped with a toroidal coil cooling structure, The cooling structure for the toroidal coil is as follows: A toroidal coil including a core and a winding wound around the core, The toroidal coil is mounted on a printed circuit board including its front and back surfaces, A metal housing is positioned on the opposite side of the front surface to the back surface of the printed circuit board, A heat dissipation grease is placed between the toroidal coil and the metal housing, A column supported by the aforementioned metal housing, It is connected to the column and comprises a retaining plate that sandwiches the toroidal coil between the metal housing, The outdoor unit comprises a fan room in which an outdoor unit fan for blowing air is located, a machine room in which the printed circuit board is located, and a partition plate separating the fan room and the machine room. The partition plate of the outdoor unit is the metal casing, The winding includes a plurality of protruding portions that extend from the core and along the surface of the printed circuit board, The protruding portion of the winding is connected to the printed circuit board so that the toroidal coil can move in a direction in which the toroidal coil overlaps the heat dissipation grease. The retaining plate is configured to press the toroidal coil against the heat dissipation grease, The aforementioned printed circuit board has an opening, The toroidal coil is arranged within the opening, Multiple of the aforementioned protruding portions are extended in at least two directions and connected to the printed circuit board. The printed circuit board is provided away from the partition plate, and its end is located within a range facing the core of the toroidal coil. The partition plate on which the toroidal coil is arranged is positioned opposite the outdoor unit fan of an air conditioning system, in the outdoor unit of an air conditioning system.

2. The cooling structure for the toroidal coil further comprises a heat sink and a first heat conductive sheet. The heat sink is sandwiched between the thermal grease and the first thermal conductive sheet. The outdoor unit of an air conditioning system according to claim 1, wherein the first heat conductive sheet is sandwiched between the heat dissipation plate and the metal housing.

3. The cooling structure for the toroidal coil further comprises a second heat conductive sheet. The second heat conductive sheet is sandwiched between the retaining plate and the toroidal coil. The outdoor unit of an air conditioning system according to claim 2, wherein the toroidal coil is pressed against the heat dissipation grease by the repulsive force of the second heat conductive sheet.

4. The cooling structure for the toroidal coil further comprises a spring-loaded screw, The retaining plate is held to the column by the spring-loaded screw, The aforementioned spring-loaded screw includes the spring, The outdoor unit of an air conditioning system according to claim 1, wherein the retaining plate is pressed against the toroidal coil by the repulsive force of the spring.

5. In a plan view, a through hole is provided in the center of the toroidal coil. The outdoor unit of the air conditioning system according to claim 1, wherein the column is inserted into the through hole.

6. The toroidal coil includes a projection that protrudes toward the metal housing, The outdoor unit of an air conditioning system according to claim 1, wherein the protruding portion is supported by the metal housing such that the winding is separated from the metal housing and is made of an insulating material.

7. The toroidal coil includes a core case that houses the core, The outdoor unit of the air conditioning system according to claim 6, wherein the core case has the protruding portion.

8. The toroidal coil includes an insulating partition plate that holds the core, The outdoor unit of the air conditioning system according to claim 6, wherein the insulating partition plate has the protruding portion.

9. The cooling structure for the toroidal coil further comprises a leaf spring, The leaf spring is fixed to the metal housing, The outdoor unit of an air conditioning system according to claim 1, wherein the toroidal coil is pressed against the metal housing side by the elastic force of the leaf spring.

Images