Electric water pump

Abstract

The invention relates to an electric water pump. The electric water pump may include: a housing having a cooling water inlet and a cooling water outlet; and a stator assembly disposed inside the housing. The stator assembly includes a stator core, a stator coil disposed on the stator core, an insulating member insulating the stator core from the stator coil, and a stator cover disposed to cover the stator core, the stator coil, and the insulating member. The electric water pump further includes: a rotor assembly rotatably disposed inside the stator assembly and having a magnet; and an impeller pumping cooling water introduced through the cooling water inlet by rotation of the rotor assembly. In particular, a stator core, a stator coil, and an insulating member of the stator assembly may be integrally formed in a stator cover.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0120239 filed in the Korean Intellectual Property Office on September 11, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to an electric water pump. Background Art

[0004] Generally speaking, the air conditioning system applied to environmentally friendly vehicles is often called a heat pump system.

[0005] The heat pump system is equipped with an electric water pump that pumps cooling water. When the impeller is rotated by the power generated by the drive motor operated by electrical energy, the electric water pump pumps the cooling water.

[0006] In order to ensure that the coil of the drive motor is insulated from the cooling water again and to prevent the coil of the drive motor from being corroded by the cooling water, a waterproof cover is provided to prevent the cooling water from being introduced into the coil of the drive motor.

[0007] The waterproof cover prevents cooling water from being introduced between a coil wound on a stator of the drive motor and a rotor having a magnet.

[0008] However, when the waterproof cover is provided between the stator and the rotor of the driving motor, the air gap between the stator and the rotor increases, and thus there is a problem that the performance of the electric water pump is degraded.

[0009] In addition, due to the presence of the waterproof cover, the axial size and radial size of the electric water pump increase, and there is a problem that it is difficult to ensure a packaging space within the limited space inside the vehicle.

[0010] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure. Therefore, the Background section may contain information that does not form the prior art that is already known to a person skilled in the art. Summary of the invention

[0011] The present disclosure is directed to providing an electric water pump capable of improving performance by minimizing an air gap formed between a stator and a rotor.

[0012] In an embodiment of the present disclosure, an electric water pump may include: a housing having a cooling water inlet and a cooling water outlet; and a stator assembly disposed inside the housing. The stator assembly may include a stator core, a stator coil arranged on the stator core, and an insulating member that insulates the stator core from the stator coil. The stator assembly may further include: a stator cover, which is configured to cover the stator core, the stator coil, and the insulating member. The electric water pump further includes: an impeller and a rotor assembly rotatably disposed inside the stator assembly. The rotor assembly may include a magnet, and the impeller is configured to pump the cooling water introduced through the cooling water inlet by the rotation of the rotor assembly. In particular, the stator core, the stator coil, and the insulating member of the stator assembly may be integrally formed in the stator cover.

[0013] In some embodiments, the stator core may include: at least one stator slot configured to receive a stator coil; and at least one stator tooth, the stator coil being wound on the at least one stator tooth. The at least one stator tooth is arranged along the circumferential direction of the stator core. In particular, the radial inner end of the stator tooth may be exposed to the radial inner side of the stator cover toward the magnet of the rotor assembly.

[0014] In some embodiments, the radially inner ends of the stator teeth may protrude radially inwardly of the stator cover by a set amount.

[0015] In some embodiments, the stator coils may be wound around the stator teeth and then the stator cover may be manufactured by injection molding.

[0016] In some embodiments, the insulation member may include an upper insulation member disposed at an upper portion of the stator core and a lower insulation member disposed at a lower portion of the stator core.

[0017] According to an embodiment, the waterproof cover in the background art is removed to reduce the axial size and radial size of the electric water pump and facilitate packaging in a limited space of a vehicle.

[0018] Furthermore, an air gap between stator teeth of the stator assembly and magnets of the rotor assembly may be minimized, and the efficiency of the drive motor may be improved.

[0019] In addition, in the detailed description of the embodiments of the present disclosure, the effects that can be obtained or predicted by the embodiments of the present disclosure are disclosed directly or implicitly. In other words, various effects predicted according to the embodiments of the present disclosure are disclosed in the detailed description to be described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are intended to describe exemplary embodiments of the present disclosure, and thus the technical spirit of the present disclosure should not be interpreted as being limited to the accompanying drawings.

[0021] Figure 1 is a cross-sectional perspective view showing the configuration of an electric water pump according to the embodiment.

[0022] Figure 2 is an exploded perspective view showing the configuration of an electric water pump according to an embodiment.

[0023] Figure 3 is a cross-sectional perspective view showing the configuration of a stator assembly according to an embodiment.

[0024] Figure 4 is an exploded perspective view showing the configuration of a stator assembly according to an embodiment.

[0025] Figure 5 is a sectional view showing the configuration of an electric water pump according to the embodiment.

[0026] Figures 6 to 9 2 is a diagram for describing a method of manufacturing a stator assembly of a drive motor according to an embodiment.

[0027] The drawings referred to above are not specifically illustrated according to scale, but should be understood as some simplified representations of various features that illustrate the basic principles of the present disclosure. For example, the specific design features of the present disclosure, including specific dimensions, directions, positions, and shapes, should be determined in part by the specific intended application and use environment.

[0028] Description of Reference Numerals

[0029] 10: Shell

[0030] 11: Upper shell

[0031] 12: Cooling water inlet

[0032] 13: Cooling water outlet

[0033] 15: Lower shell

[0034] 20: Rotor

[0035] 21: Rotor body

[0036] 23: Magnet

[0037] 25: Bearings

[0038] 27: Impeller

[0039] 30: Stator assembly

[0040] 40: stator core

[0041] 41: Stator teeth

[0042] 43: Stator slot

[0043] 45: Stator coil

[0044] 50: Stator cover

[0045] 51: Cover protrusion

[0046] 53: Central axis

[0047] 60: Upper insulation member

[0048] 70: Lower insulation member

[0049] 80: Drive motor DETAILED DESCRIPTION

[0050] The terms used herein are only used to describe specific embodiments and are not intended to limit the present disclosure to specific embodiments. As used herein, unless the context has clear different instructions, the singular form is also intended to include the plural form. It should be understood that when the terms "including" and / or "including" are used in this specification, the terms "including" and / or "including" are intended to specify the existence of the described features, integers, steps, operations, constituent elements and / or parts, but do not exclude the existence or addition of one or more other features, integers, operations, constituent elements and parts or their groups. As used herein, the term "and / or" includes any one and all combinations of the associated and listed items.

[0051] By referring to the accompanying drawings, the present disclosure is described in detail so that those skilled in the art in the art to which the present disclosure belongs can easily perform the present disclosure. However, the present disclosure can be implemented in various different forms and is not limited to the specific embodiments described herein.

[0052] In order to clearly describe the present disclosure, parts irrelevant to the description have been omitted, and the same or similar elements are denoted by the same reference numerals throughout the specification.

[0053] In addition, since the size and thickness of each component shown in the drawings are arbitrarily represented for convenience of explanation, the present disclosure is not particularly limited to the size and thickness of each component shown, and in order to clearly represent each part and region, the thickness is exaggerated and shown.

[0054] The suffixes “module” and / or “unit” of components used in the following description are given or mixedly used only in consideration of convenience of description and have no distinguished meaning or function of their own.

[0055] Furthermore, when describing specific embodiments, if it is determined that the detailed description makes the gist of the embodiments of the present disclosure unclear, the detailed description of the related known technology will be omitted.

[0056] In addition, the drawings are provided to help easily understand the embodiments disclosed in this specification. The technical spirit disclosed in this specification is not limited by the drawings, and it should be understood that the present disclosure includes all modifications, equivalents and replacements included in the spirit and technical scope of the present disclosure.

[0057] Terms including common numerals such as first and second are used to describe various constituent elements, but the constituent elements are not limited by these terms. These terms are used only to distinguish one component from another.

[0058] In the following description, unless an explicit expression such as "a" or "an" is used, an expression described in the singular may be construed as being in the singular or in the plural.

[0059] When a component, device, element, etc. of the present disclosure is described as having a purpose or performing an operation, function, etc., the component, device or element should be considered herein as being "configured to" satisfy that purpose or perform that operation or function.

[0060] It should be understood that when it is described that a component is “connected to” or “accessed to” another component, the component may be directly connected to or accessed to the other component, or a third component may exist therebetween.

[0061] On the contrary, when it is described that a component is “directly connected to” or “directly accesses” another component, it can be understood that there are no elements between the component and the other component.

[0062] Hereinafter, an electric water pump according to an embodiment is described in detail with reference to the accompanying drawings.

[0063] Figure 1 : is a partial cross-sectional perspective view showing the configuration of the electric water pump according to the embodiment. Figure 2 is an exploded perspective view showing the configuration of an electric water pump according to an embodiment.

[0064] like Figure 1 and Figure 2 As shown, the electric water pump may include a housing 10 having a cooling water inlet 12 and a cooling water outlet 13, an impeller 27 disposed inside the housing 10, and a driving motor 80 including a rotor assembly 20 and a stator assembly 30 (hereinafter, referred to as a "stator" when necessary).

[0065] The housing 10 may include an upper housing 11 and a lower housing 15. The upper housing 11 is formed in a generally hollow cylindrical shape, and the lower portion is open. The lower housing 15 is formed in a generally hollow cylindrical shape, and the upper portion is open. The impeller 27 and the drive motor 80 including the stator assembly 30 and the rotor assembly 20 may be disposed in an internal space formed by coupling the upper housing 11 and the lower housing 15.

[0066] A cooling water inlet 12 for introducing cooling water may be formed at the upper center of the upper shell 11, and a cooling water outlet 13 for discharging cooling water may be formed on the side surface of the upper shell 11. A sealing member may be provided between the radially outer lower portion of the upper shell 11 and the radially outer upper portion of the lower shell 15. When the upper shell 11 and the lower shell 15 are coupled, cooling water may be prevented from leaking to the outside of the shell 10 by the sealing member.

[0067] The driving motor 80 includes a stator assembly 30 and a rotor assembly 20 , and generates power for actuating the impeller 27 through electromagnetic interaction with the stator assembly 30 and the rotor assembly 20 .

[0068] Figure 3 is a partial cross-sectional perspective view showing the configuration of the stator assembly 30 according to the embodiment. Figure 4 is an exploded perspective view showing the configuration of the stator assembly 30 according to the embodiment.

[0069] Reference Figure 3 and Figure 4 The stator assembly 30 may include a stator core 40 , a stator coil 45 wound on the stator core 40 , insulating members 60 and 70 insulating the stator core 40 from the stator coil 45 , and a stator cover 50 .

[0070] The stator core 40 may be formed in a shape approximately like a circular ring and made of a metal material to fully form a rotating magnetic field. At least one stator slot 43 may be formed along the circumferential direction of the stator core 40, and one or more stator teeth 41 may be arranged along the circumferential direction of the stator core 40. The stator teeth 41 may extend in the radial direction of the stator core 40, and the radial inner ends of the stator teeth 41 may expand to both sides along the circumferential direction. Figure 4 As shown, a plurality of stator slots 43 are arranged in the circumferential direction of the stator core 40, and at least one stator tooth 41 is arranged between adjacent stator slots 43. In the same manner, each stator tooth 41 is arranged between corresponding adjacent stator slots 43 (see Figure 4 The stator coils 45 are wound around the corresponding stator teeth 41. The number of the stator teeth 41 can be appropriately adjusted according to the requirements of the stable driving characteristics of the driving motor 80.

[0071] The insulating members 60 and 70 may include an upper insulating member 60 disposed at an upper portion of the stator core 40 and a lower insulating member 70 disposed at a lower portion of the stator core 40. The upper insulating member 60 may be formed in a shape corresponding to the upper portion of the stator core 40, and the lower insulating member 70 may be formed in a shape corresponding to the lower portion of the stator core 40. The upper insulating member 60 and the lower insulating member 70 are disposed at an upper portion and a lower portion of the stator core 40, respectively, and then the stator coil 45 is wound around the stator teeth 41. The upper insulating member 60 and the lower insulating member 70 electrically insulate the stator core 40 and the stator coil 45.

[0072] The stator case 50 is provided to integrally cover the stator core 40, the upper insulation member 60, the lower insulation member 70, and the stator coil 45. The stator core 40, the stator coil 45, and the upper and lower insulation members 60 and 70 of the stator assembly 30 may be integrally formed in the stator case 50.

[0073] To this end, in the stator cover 50, the upper insulating member 60 is provided at the upper part of the stator core 40, the lower insulating member 70 is provided at the lower part of the stator core 40, and then the stator coil 45 is wound on the stator core. The stator core 40 wound with the stator coil 45 is integrally injection molded to form the stator cover 50. The stator cover 50 is formed in an approximately toroidal shape, has an installation space at the center so that the rotor assembly 20 can be rotatably provided, and has a cover protrusion 51 coupled to the center shaft 53 at the lower center.

[0074] When the stator cover 50 is injection molded, the radial inner ends of the stator teeth 41 of the stator core 40 may be exposed to the radial inner side of the stator cover 50. In an embodiment, the radial inner ends of the stator teeth 41 may be formed to protrude by a set amount on the radial inner side of the stator cover 50. Since the radial inner ends of the stator teeth 41 protrude on the radial inner side of the stator cover 50, the air gap formed between the stator teeth 41 and the magnets 23 of the rotor assembly 20 may be minimized, and therefore, the efficiency of the drive motor 80 may be improved.

[0075] Return to reference Figure 1 and Figure 2 The rotor assembly 20 is rotatably disposed at the center of the stator case 50. The rotor assembly 20 is installed at the inner center of the stator assembly 30, and rotates by electromagnetic action with the stator coil 45 wound on the stator core 40.

[0076] The rotor assembly 20 may include a rotor body 21 and at least one magnet 23 disposed in the rotor body 21 .

[0077] The rotor body 21 is formed in a substantially hollow cylindrical shape and is rotatably disposed on a central shaft 53 fixedly mounted at a cover protrusion 51 of a stator cover 50. A bearing 25 may be disposed between the central shaft 53 mounted in the stator cover 50 and the rotor body 21. In other words, the rotor body 21 of the rotor assembly 20 is rotatably supported on the central shaft 53 through the bearing 25.

[0078] At least one magnet 23 is disposed on the radially outer side of the rotor body 21. The magnet 23 may be a permanent magnet. A plurality of magnets 23 may be disposed in the circumferential direction of the rotor body 21.

[0079] According to an embodiment, the drive motor 80 is implemented as a radial flux motor (RFM) having a stator core 40 of a stator assembly 30 and magnets 23 of a rotor assembly 20 located radially inside the stator core 40. The RFM is a motor in which magnetic flux generated from magnets of a rotor moves in a radial direction.

[0080] The magnets 23 provided in the rotor assembly 20 and the radially inner ends of the stator teeth 41 of the stator core 40 are arranged to be spaced apart from each other by a predetermined interval. The magnets 23 of the rotor assembly 20 and the radially inner ends of the stator teeth 41 are spaced apart from each other to form an air gap. As the distance of the air gap is reduced, the efficiency of the drive motor 80 including the rotor assembly 20 and the stator is improved.

[0081] The impeller 27 may be provided at an upper portion of the rotating body 21 of the rotor assembly 20. The impeller 27 rotates with the rotation of the rotor assembly 20, and pumps cooling water introduced through the cooling water inlet 12 formed in the housing 10, and the cooling water pumped by the impeller 27 is discharged to the outside through the cooling water outlet 13. In the embodiment, the rotor shaft 21 of the rotor assembly 20 and the impeller 27 are integrally provided as an example, but the present disclosure is not particularly limited thereto, and the rotor assembly 20 and the impeller 27 may also be formed as separate components.

[0082] Reference Figure 5 According to an embodiment, a conventional waterproof cover is removed from a driving motor 80 embedded in an electric water pump.

[0083] In the prior art, the air gap formed between the stator assembly 30 and the rotor assembly 20 of the drive motor 80 is formed to be about 2 mm by a waterproof cover. However, by removing the waterproof cover in the prior art, according to an embodiment of the present disclosure, the air gap between the stator assembly 30 and the rotor assembly 20 of the drive motor 80 can be formed to be less than about 1 mm (basically, about 0.5 mm). In this way, the air gap between the stator assembly 30 and the rotor assembly 20 is minimized to improve the efficiency and output of the drive motor 80 embedded in the electric water pump.

[0084] Reference Figures 6 to 9 , a method for manufacturing the stator assembly 30 is described in detail.

[0085] The stator core 40 is located at a set position (see Figure 6 ), the upper insulating member 60 and the lower insulating member 70 are respectively disposed at the upper and lower portions of the stator core 40 (see Figure 7 ).

[0086] After the stator core 40, the upper insulating member 60, and the lower insulating member 70 are disposed, the stator coil 45 is wound around the stator teeth 41 (see Figure 8). The number of the stator coils 45 may be the same as the number of the stator teeth 41. In other words, the number of the stator teeth 41 is equal to the number of the stator coils 45, and the stator coils 45 are respectively wound on the stator teeth 41.

[0087] The stator coil 45 is wound around the stator teeth 41 and then formed into a stator cover 50 by injection molding (see Fig. 9 ).

[0088] In this way, the stator core 40 and the stator coil 45 are arranged inside the stator cover 50. Therefore, the stator core 40 and the stator coil 45 can be prevented from being corroded by the cooling water introduced into the housing 10. Therefore, the function of the waterproof cover in the prior art is replaced by the stator cover 50, thereby reducing the axial size and radial size of the electric water pump. In addition, the air gap between the stator assembly 30 and the rotor assembly 20 is minimized. This improves the efficiency of the drive motor 80.

[0089] Although the embodiments of the present disclosure are disclosed for illustrative purposes, it will be appreciated by those skilled in the art that various modifications, additions and substitutions may be made without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims and their equivalents.

Claims

1. An electric water pump, comprising: A housing having a cooling water inlet and a cooling water outlet; A stator assembly is arranged inside the housing, wherein the stator assembly comprises: stator core, A stator coil is arranged on the stator core, an insulating member for insulating the stator core from the stator coil, and a stator cover configured to cover the stator core, the stator coil, and the insulating member; a rotor assembly rotatably disposed inside the stator assembly and having a magnet; and an impeller for pumping cooling water introduced through the cooling water inlet by the rotation of the rotor assembly, The stator core, the stator coil, and the insulating member are integrally formed in the stator case.

2. The electric water pump according to claim 1, wherein: The stator core comprises: at least one stator slot receiving the stator coil, and at least one stator tooth, the stator coil is wound around the at least one stator tooth, the at least one stator tooth is arranged along the circumferential direction of the stator core, and A radially inner end of the at least one stator tooth is exposed to the radial inner side of the stator cover toward the magnets of the rotor assembly.

3. The electric water pump according to claim 2, wherein: A radially inner end of the at least one stator tooth protrudes radially inwardly of the stator cover by a set amount.

4. The electric water pump according to claim 2, wherein: The stator coil is wound around the at least one stator tooth, and then the stator bell is manufactured by injection molding.

5. The electric water pump according to claim 1, wherein: The insulating member includes an upper insulating member disposed on an upper portion of the stator core, and The lower insulating member is disposed at the lower portion of the stator core.

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