Varnish impregnation device for stator coil windings

Abstract

The present disclosure relates to a varnish impregnation device, comprising: a lower housing having a stator seated therein, the stator including a stator core, an upper insulator, a lower insulator, and coil windings, the stator core having a plurality of teeth protruding inwardly or outwardly and having slots as spaces between the teeth, the upper insulator and the lower insulator being coupled to the upper and lower portions of the stator core, respectively, and the coil windings passing through the slots and being wound around the teeth; a lower sealing portion coupled to the lower portion of the stator seated in the interior space of the lower housing; a central sealing portion on the lower sealing portion; an upper sealing portion on the central sealing portion; a first covering member coupled to the upper portion of the upper sealing portion and the inner upper portion of the upper insulator; and a second covering member coupled to the upper outer portion of the stator core and the outer periphery of the upper insulator and spaced a distance from the circumference of the first covering member. The lower housing has a plurality of varnish supply holes extending vertically through its lower surface and communicating with the slots.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Korean Patent Application No. 10-2023-0056075, filed on April 28, 2023, which is hereby incorporated by reference in its entirety for all purposes. Technical Field

[0003] The present disclosure relates to a varnish impregnation device for stator coil windings, and more particularly to a varnish impregnation device of a novel structure, which applies varnish to coil windings included in the stator of a motor by means of vacuum impregnation, so that the varnish is applied only to necessary portions of the material to be impregnated, thereby improving product quality and production efficiency. Background Art

[0004] Generally, the stator of a motor includes a stator core, an upper insulator coupled to the top of the stator core, a lower insulator coupled to the bottom of the stator core, and coil windings wound around the teeth. The coil windings are wound around the teeth and are located in slots, which serve as spaces between the teeth.

[0005] Such motors are used in various fields such as household appliances, automobiles, and robots. In particular, in motors used in humid environments, such as compressors of refrigerators or air conditioners, fluids such as moisture may come into contact with the coil windings. Therefore, unless the surface of the coil windings is insulated, the coil windings may short-circuit due to moisture, etc. This may cause motor failure or fire. Therefore, in order to prevent product defects due to low insulation resistance of the coil windings, it is necessary to obtain an insulation resistance above a certain level on the surface of the coil windings.

[0006] One method for increasing insulation resistance involves dipping a stator into varnish to form a varnish film on the surface of a coil winding. Japanese Patent Application Laid-Open Publication No. S60-77650, a prior art method for applying varnish to a coil winding, discloses dipping a stator, the material to be impregnated, into a varnish impregnation solution. Japanese Patent Application Laid-Open Publication No. Hei 06-36954 discloses a method for applying varnish to a coil winding by dripping varnish from the top while conveying an electrical component, such as a stator, on a conveyor belt.

[0007] However, in these prior arts, varnish is applied by dipping the stator into a varnish impregnation liquid or by dripping varnish from the top of the stator, so that the varnish liquid remains on the inner and outer surfaces of the stator in addition to the coil windings, etc. Therefore, in order to improve the quality and performance of the motor, the varnish remaining on the inner and outer surfaces of the stator must be removed to obtain the inner and outer diameter dimensions of the stator core.

[0008] Furthermore, since separate processes must be performed to remove the varnish remaining on the inner and outer surfaces of the stator, the motor manufacturing process for increasing the insulation resistance in the coil windings is complicated, resulting in reduced productivity and increased manufacturing costs for the motor assembly. Furthermore, it is difficult to completely remove the varnish remaining on the inner and outer surfaces of the stator, which can lead to a decrease in motor quality and an increase in defect rates.

[0009] Therefore, in order to solve the above-mentioned problems, the present disclosure proposes a varnish impregnation device of a novel structure that supplies varnish to a coil winding and performs vacuum impregnation. Summary of the Invention

[0010] An object of the present disclosure is to provide a varnish impregnation device of a novel structure capable of increasing the insulation resistance of a coil winding by applying varnish only on a portion of the coil winding excluding the inner and outer surfaces of a stator.

[0011] An object of the present disclosure is to provide a varnish impregnation device with a novel structure, which can improve productivity and reduce manufacturing costs.

[0012] All of the above objects and other inherent objects can be easily achieved by the following embodiments of the present disclosure.

[0013] One embodiment is a varnish impregnation device comprising: a lower shell in which a stator is seated in an interior space of the lower shell, the stator including a stator core, an upper insulator and a lower insulator, and a coil winding, the stator core having a plurality of teeth protruding inwardly or outwardly and having slots as spaces between the teeth, the upper insulator and the lower insulator being coupled to an upper portion and a lower portion of the stator core, respectively, the coil winding passing through the slots and being wound around the teeth; a lower sealing portion coupled to a lower portion of an interior space of the stator seated in the interior space of the lower shell; a central sealing portion positioned above the lower sealing portion; an upper sealing portion positioned above the central sealing portion; a first covering member coupled to an upper portion of the upper sealing portion and an inner upper portion of the upper insulator; and a second covering member coupled to an upper outer portion of the stator core and an outer periphery of the upper insulator and being spaced a certain distance from a circumference of the first covering member. The lower case has a plurality of varnish supply holes formed through the lower surface of the lower case up and down, and the plurality of varnish supply holes communicate with the slit.

[0014] A first packaging member is installed between an upper portion of the central sealing portion and a lower portion of the upper sealing portion and seals the upper portion of the inner space of the stator core to prevent varnish from flowing into the upper portion of the inner space of the stator core.

[0015] A second packaging member is installed between a lower portion of the central sealing portion and an upper portion of the lower sealing portion and seals the lower portion of the inner space of the stator core to prevent varnish from flowing into the lower portion of the inner space of the stator core.

[0016] A pair of fixed supports are formed to protrude upward from the outer wall of the lower housing. The fixed supports are connected to fastening portions via hinges, and the fastening portions are rotatably connected via the hinges. A bent portion, formed at the top of the fastening portions, fastens and compresses the first and second covering members.

[0017] The varnish impregnation device further includes a support member mounted on a bottom surface of the inner space of the lower case and mounted on a lower inner diameter portion of the lower insulator of the stator.

[0018] A third packaging member is installed between the lower inner diameter portion of the lower insulator and the support member, and the third packaging member prevents the varnish from flowing into the interior of the lower insulator.

[0019] A fourth packing member is mounted on the outermost peripheral portion of the bottom surface of the inner space of the lower case and seals the lower outer diameter portion of the lower insulator to prevent varnish from flowing into the lower outer diameter portion of the lower insulator.

[0020] A fifth packaging member is mounted on the circumference of the bottom surface of the first cover member and seals an upper inner diameter portion of the upper insulator, thereby preventing varnish from flowing from an upper portion of the stator into an inner surface of the stator.

[0021] A sixth packaging member is mounted on the bottom surface of the second cover member and seals an upper outer diameter portion of the upper insulator to prevent varnish from flowing from an upper portion of the stator into an outer surface of the stator.

[0022] According to an embodiment of the present disclosure, the stator is placed in a varnish impregnation device, which is located within a vacuum chamber and uses a vacuum pressurization method to supply varnish to the stator's slots to impregnate the coil windings. As a result, the insulation resistance is increased, improving the insulation efficiency of the coil windings.

[0023] According to the embodiment of the present disclosure, the varnish supply holes of the lower housing of the varnish impregnation device correspond to the slots of the stator and supply varnish. Therefore, varnish can be supplied quickly and the time of applying varnish to the coil winding is shortened, thereby having the effect of improving productivity.

[0024] According to an embodiment of the present disclosure, varnish is not applied to the inner and outer surfaces of the stator except for the coil windings, so that the inner and outer diameters of the stator do not vary, thereby reducing the defect rate of the stator and improving product quality.

[0025] According to the embodiments of the present disclosure, since varnish is applied only to the coil windings, excluding the inner and outer surfaces of the stator, the process of removing varnish that may remain on the inner or outer surfaces of the stator core is omitted, thereby shortening the manufacturing process and improving productivity. Consequently, the cost of stator manufacturing is reduced.

[0026] According to an embodiment of the present disclosure, varnish is impregnated and applied only to coil windings arranged in slots of a stator, thereby reducing varnish consumption and lowering manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a perspective view showing a varnish impregnation device according to an embodiment of the present disclosure;

[0028] Figure 2 is a perspective view showing a varnish impregnation device according to an embodiment of the present disclosure from below;

[0029] Figure 3 is an exploded perspective view of a varnish impregnation device according to an embodiment of the present disclosure;

[0030] Figure 4 is a cross-sectional view of a varnish impregnation apparatus according to an embodiment of the present disclosure;

[0031] Figure 5 is a cross-sectional view showing a state in which a stator is separated from a varnish impregnation device according to an embodiment of the present disclosure; and

[0032] Figure 6 is a cross-sectional view showing that a varnish impregnation device according to an embodiment of the present disclosure is installed in a vacuum chamber; and

[0033] Figure 7 is a conceptual diagram illustrating a process sequence of a method of varnish impregnating a stator coil winding using the varnish impregnation apparatus according to an embodiment of the present disclosure.

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] Figure 1 is a perspective view showing a varnish impregnation device 100 according to an embodiment of the present disclosure. Figure 2 is a perspective view showing the varnish impregnation device 100 according to the embodiment of the present disclosure from below. Figure 3 is an exploded perspective view of a varnish impregnation device 100 according to an embodiment of the present disclosure. Figure 4 is a cross-sectional view of a varnish impregnation device 100 according to an embodiment of the present disclosure. Figure 5 is a cross-sectional view showing a state in which a stator is separated from a varnish impregnation device according to an embodiment of the present disclosure.

[0036] like Figures 1 to 5 As shown in FIG, the varnish impregnation device 100 according to an embodiment of the present disclosure includes a lower housing 110, a lower sealing portion 120, a central sealing portion 130, an upper sealing portion 140, a first covering member 150, and a second covering member 160. The varnish impregnation device 100 is detachably installed in the vacuum chamber 200.

[0037] The lower shell 110 has a cup shape with an open top and is seated on the seating portion 230 of the vacuum chamber 200. The stator 600 is seated inside the lower shell 110. The lower shell 110 has a plurality of varnish supply holes 111 formed to pass through the lower surface of the lower shell 110 up and down. The space inside the lower shell 110 has an internal space 112, and the stator 600 is seated in this internal space 112. A pair of fixed supports 113 are formed to protrude upward from the outer wall of the lower shell 110. The fixed supports 113 can be formed integrally with the lower shell 110, or can be formed as a component separate from the lower shell 110 and connected to each other. The fixed support 113 is connected to a fastening portion 115 via a hinge 114. The fastening portion 115 is rotatably connected via the hinge 114. The bent portion 115A formed to be bent at the top of the fastening portion 115 fastens and compresses the first covering member 150 and the second covering member 160 .

[0038] The stator 600 includes: a stator core 610, which has a plurality of teeth protruding inward or outward and slots 611, which are spaces between the teeth; an upper insulator 613 and a lower insulator 614 respectively coupled to the upper and lower portions of the stator core 610; and a coil winding 612 passing through the slots 611 and wound around the teeth.

[0039] The lower sealing portion 120 is coupled to the lower portion of the interior space of the stator 600 seated in the interior space 112 of the lower housing 110. The central sealing portion 130 is positioned above the lower sealing portion 120. A second encapsulation member P2 is installed between the upper portion of the lower sealing portion 120 and the lower portion of the central sealing portion 130. The second encapsulation member P2 seals the lower portion of the interior space of the stator core 610 of the stator 600, thereby preventing varnish from flowing into the lower portion of the interior space of the stator core 610. Although the lower sealing portion 120 and the central sealing portion 130 are described as separate components, they can be integrally formed as a one-piece. In addition, the lower sealing portion 120 and the central sealing portion 130 do not have to be firmly coupled to the inner surface of the stator 600 and may not be in contact with the inner surface. This is because the lower portion of the interior space of the stator core 610 is sealed by the second encapsulation member P2.

[0040] The upper sealing portion 140 is mounted above the central sealing portion 130. A first packaging member P1 is mounted between a lower portion of the upper sealing portion 140 and an upper portion of the central sealing portion 130. Thus, the first packaging member P1 seals the upper portion of the interior space of the stator core 610, thereby preventing the varnish B from flowing into the upper portion of the interior space of the stator core 610.

[0041] The first cover member 150 is coupled with the upper portion of the upper sealing portion 140 and the inner upper portion of the upper insulator 613 so that the varnish B is prevented from flowing into the upper portion of the inner space of the stator 600. The first cover member 150 and the upper sealing portion 140 may be integrally formed as one piece.

[0042] The second cover member 160 is coupled to the upper outer portion of the stator core 610 and the outer circumference of the upper insulator 613, and is spaced a certain distance from the circumference of the first cover member 150 so that the varnish B is prevented from flowing downward to the upper outer surface of the stator 600. The second cover member 160 may be connected to the first cover member 150 at a certain distance by a plurality of bridges (not shown) so that the first cover member 150 and the second cover member 160 may be a single member.

[0043] The varnish impregnation device 100 according to an embodiment of the present disclosure has the following structure: in this structure, a fastening portion 115, which is rotatably coupled to a fixed support 113 of a lower housing 110 on which a stator 600 is seated, covers a first cover member 150 and a second cover member 160. A plurality of varnish supply holes 111 formed in the lower portion of the lower housing 110 communicate with slots 611, which are the spaces between the teeth of the stator core 610. Coil windings 612 are positioned in the slots 611. Varnish B is supplied from the lower portion of the varnish supply holes 111, moves upward through the slots 611, and impregnates the upper portion of the coil windings 612.

[0044] The support member 116 is mounted on the bottom surface of the interior space 112 of the lower housing 110 and is also mounted on the lower inner diameter portion of the lower insulator 614 of the stator 600. A third packaging member P3 is mounted between the lower inner diameter portion of the lower insulator 614 and the support member 116, and prevents varnish from flowing into the interior of the lower insulator 614.

[0045] The fourth packaging member P4 is mounted on the outermost portion of the bottom surface of the interior space 112 of the lower case 110 and seals the lower outer diameter portion of the lower insulator 614. Thus, the varnish is prevented from flowing into the lower outer surface of the lower insulator 614.

[0046] A fifth packaging member P5 is mounted on the circumference of the bottom surface of the first cover member 150. The fifth packaging member P5 seals the upper inner diameter portion of the upper insulator 613, thereby preventing varnish from flowing from the upper portion of the stator 600 into the inner surface of the stator 600.

[0047] A sixth packaging member P6 is mounted on the bottom surface of the second cover member 160. The sixth packaging member P6 seals the upper outer diameter portion of the upper insulator 613, thereby preventing varnish from flowing from the upper portion of the stator 600 into the outer surface of the stator 600.

[0048] Figure 6 2 is a cross-sectional view showing that the varnish impregnation device 100 according to an embodiment of the present disclosure is installed in the vacuum chamber 200. Figure 6The varnish impregnation device 100 according to an embodiment of the present disclosure is installed in a recessed seating portion 230 formed on the bottom surface of a cup-shaped vacuum chamber 200 with an open top. A vacuum cover 220 is installed on the vacuum chamber 200, and the vacuum cover 220 seals the interior space of the vacuum chamber 200. An air passage 210 is installed on one side of the vacuum chamber 200. The air passage 210 exhausts the air within the vacuum chamber 200 to the outside, thereby placing the vacuum chamber in a vacuum state. Conversely, when the interior of the vacuum chamber 200 is in a vacuum state, the air passage 210 introduces external air into the vacuum chamber 200, thereby creating a state of equilibrium with the external air pressure.

[0049] A varnish supply passage 231 is formed in the center portion of the seating portion 230. This varnish supply passage 231 communicates with a varnish supply hole 111 formed in the lower housing 110 of the varnish impregnation device 100. The varnish supply passage 231 is connected to the pipe 300 through which the varnish B is supplied. The vacuum chamber 200 may be mounted on a support frame 700. A connection hole 710 is formed in the support frame 700, through which the pipe 300 passes.

[0050] As described above, in an embodiment of the present disclosure, the central sealing portion 130, the lower sealing portion 120, and the upper sealing portion 140 can be formed integrally and provided as one component. In addition, the first covering member 150 and the second covering member 160 can also be formed integrally and provided as one component. The first packaging member P1 to the sixth packaging member P6 of the embodiment of the present disclosure can use rubber, but are not necessarily limited to this. The first packaging member P1 to the sixth packaging member P6 can use various materials such as silicone resin and flexible resin.

[0051] In the embodiment of the present disclosure, although it has been described above that one varnish impregnation device 100 is provided in the vacuum chamber 200, a plurality of varnish impregnation devices 100 may be provided and used in one vacuum chamber 200. In addition, it is permissible to use a plate (not shown) to mount the plurality of varnish impregnation devices 100. In this case, the plate must include a channel formed therein that communicates with each varnish impregnation device 100 and supplies the varnish B through the pipe 300.

[0052] Figure 7 1 is a conceptual diagram showing the process sequence of a method for varnish impregnating a stator coil winding using the varnish impregnation device 100 according to an embodiment of the present disclosure. Figure 7As shown in FIG, a varnish impregnation device 100 according to an embodiment of the present disclosure is installed in a vacuum chamber 200. The vacuum chamber 200 is connected to a varnish storage tank 400 that stores varnish B via a pipe 300. A valve V is installed in the pipe 300, and the valve V controls the supply of varnish B from the varnish storage tank 400 to the vacuum chamber 200. An air pump 500 is connected to an air passage 210 formed in the vacuum chamber 200. The air pump 500 can remove air from the vacuum chamber 200 or supply external air to the vacuum chamber 200.

[0053] like Figure 7 As shown in (a), the varnish impregnation method of the stator according to an embodiment of the present invention includes a first step of maintaining the interior of the vacuum chamber 200 in a vacuum state by discharging the air in the vacuum chamber 200 to the outside with the help of an air pump 500 while the stator 600 is seated on the varnish impregnation device 100 installed in the vacuum chamber 200.

[0054] In the next second step, Figure 7 As shown in (b), by opening the valve V connected to the middle of the pipe 300 in the above-mentioned first step, the varnish B stored in the varnish storage tank 400 is injected into the narrow groove 611 of the stator core 610 through the varnish supply hole 111 formed in the lower shell 110 of the varnish impregnation device 100.

[0055] When the varnish B is injected into the slots 611 of the stator core 610 in such a vacuum state, the inner and outer surfaces of the stator core 610 are not impregnated with the varnish B. Therefore, the varnish B is intended to be impregnated and applied only to the inside of the slots 611 and the coil windings 612, and is not intended to be applied only to the inner and outer surfaces of the stator core 610.

[0056] In the next third step, if Figure 7 As shown in (c), the air pressure in the vacuum chamber 200 is balanced with the external air pressure by the natural inflow of external air by utilizing the air pressure difference between the inside and the outside or by the air pump 500 in the second step described above. Then, by opening the valve V and applying positive pressure by operating the air pump 500, the varnish B is discharged from the vacuum chamber 200 and transferred again to the varnish storage tank 400.

[0057] In the next fourth step, if Figure 7 As shown in (d) of FIG. 5 , when the discharge of the varnish B from the vacuum chamber 200 in the third step is completed, the valve V is closed and the operation of the air pump 500 is stopped.

[0058] In the next fifth step, if Figure 7As shown in (e), the vacuum cover 220 of the vacuum chamber 200 is opened, and the stator 600 seated in the varnish impregnation device 100 is separated from the varnish impregnation device. Then, the stator 600 is taken out of the vacuum chamber 200 and transferred to the curing device 800. Then, the varnish B applied to the coil winding 612 is cured.

[0059] The varnish impregnation method for stator coil windings according to an embodiment of the present invention can prevent defects caused by dimensional changes due to the application of varnish B to the inner and outer surfaces of the stator 600. In addition, a separate process for removing varnish B can be omitted, thereby improving the productivity of the stator 600, and the consumption of varnish B can be reduced, thereby reducing the manufacturing cost of the stator 600.

[0060] It should be noted that the above detailed description of the present invention is merely an example for understanding the present invention and is not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims, and any simple modification or change to the present invention within the scope of the claims should be understood to fall within the scope of the present invention.

[0061] Reference numerals

[0062] 100: Varnish impregnation device 110: Lower shell

[0063] 111: Varnish supply hole 112: Internal space

[0064] 113: Fixed support 114: Hinge

[0065] 115: Fastening part 115A: Bending part

[0066] 116: Support member 120: Lower sealing portion

[0067] 130: Central sealing part 140: Upper sealing part

[0068] 150: First covering member 160: Second covering member

[0069] 200: Vacuum chamber 210: Air channel

[0070] 220: Vacuum cover 230: Seating part

[0071] 231: Varnish supply channel 300: Pipeline

[0072] 400: Varnish storage tank 500: Air pump

[0073] 600: stator 610: stator core

[0074] 611: Slot 612: Coil winding

[0075] 613: Upper insulator 614: Lower insulator

[0076] 700: Support frame 710: Connection hole

[0077] 800: Curing device B: Varnish

[0078] V: Valves P1 to P6: First to sixth packaging members

Claims

1. A varnish impregnation device for stator coil windings, the varnish impregnation device comprising: a lower housing, wherein a stator is seated in an inner space of the lower housing, the stator including a stator core, an upper insulator and a lower insulator, and a coil winding, the stator core having a plurality of teeth protruding inward or outward and having slots, the slots being spaces between the teeth, the upper insulator and the lower insulator being coupled to an upper portion and a lower portion of the stator core, respectively, and the coil winding passing through the slots and being wound around the teeth; a lower sealing portion coupled to a lower portion of an interior space of the stator seated in the interior space of the lower housing; a central sealing portion positioned above the lower sealing portion; an upper sealing portion positioned above the central sealing portion; a first covering member coupled with an upper portion of the upper sealing portion and an inner upper portion of the upper insulator; and a second covering member coupled to an upper outer portion of the stator core and an outer circumference of the upper insulator and spaced apart from a circumference of the first covering member, The lower shell has a plurality of varnish supply holes formed to pass through the lower surface of the lower shell up and down, and the plurality of varnish supply holes are communicated with the narrow groove.

2. The varnish impregnation device for stator coil windings according to claim 1, wherein: A first packaging member is installed between an upper portion of the central sealing portion and a lower portion of the upper sealing portion and seals an upper portion of an inner space of the stator core to prevent varnish from flowing into the upper portion of the inner space of the stator core.

3. The varnish impregnation device for stator coil windings according to claim 1, wherein: A second packaging member is installed between a lower portion of the central sealing portion and an upper portion of the lower sealing portion, and the second packaging member seals the lower portion of the inner space of the stator core, thereby preventing the varnish from flowing into the lower portion of the inner space of the stator core.

4. The varnish impregnation device for stator coil windings according to claim 1, wherein: A pair of fixed supports are formed protruding upward from the outer wall of the lower shell, wherein the fixed supports are connected to a fastening portion via a hinge, and the fastening portion is rotatably connected via the hinge, and wherein a bent portion formed to be bent at the top of the fastening portion fastens and presses the first covering member and the second covering member. 5 . The varnish impregnation device of the stator coil winding according to claim 1 , further comprising a support member installed on a bottom surface of the inner space of the lower case and on a lower inner diameter portion of the lower insulator of the stator.

6. The varnish impregnation device for stator coil windings according to claim 5, wherein: A third packing member is installed between the lower inner diameter portion of the lower insulator and the support member, and the third packing member prevents varnish from flowing into the interior of the lower insulator.

7. The varnish impregnation device for stator coil windings according to claim 1, wherein: A fourth packing member is mounted on the outermost peripheral portion of the bottom surface of the inner space of the lower case and seals the lower outer diameter portion of the lower insulator to prevent varnish from flowing into the lower outer diameter portion of the lower insulator.

8. The varnish impregnation device for stator coil windings according to claim 1, wherein: A fifth packaging member is mounted on the circumference of the bottom surface of the first cover member and seals an upper inner diameter portion of the upper insulator to prevent varnish from flowing from an upper portion of the stator into an inner surface of the stator.

9. The varnish impregnation device for stator coil windings according to claim 1, wherein: A sixth packaging member is mounted on the bottom surface of the second cover member and seals an upper outer diameter portion of the upper insulator to prevent the varnish from flowing from the upper portion of the stator into the outer surface of the stator.

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