Electronic water pump

Abstract

The present application provides an electronic water pump, the water pump comprising a stator assembly (S), a rotor assembly (R), and an impeller assembly (T), wherein the stator assembly (S) comprises a stator core (S1) and a stator injection-molded layer (S0), and the stator injection-molded layer (S0) encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core (S1), the impeller assembly (T) comprises an impeller (T1) and a volute (T0) that encloses the impeller (T1), the stator injection-molded layer (S0) and the volute (T0) are welded together by means of fusion; the electronic water pump further comprises a controller (C) and a heat dissipation plate (P), and the volute (T0) further encloses the controller (C) and the heat dissipation plate (P). The application also provides a corresponding stator assembly (S) and an assembly of stator assembly (S) and volute (T0).

Description

ELECTRONIC WATER PUMPTECHNICAL FIELD

[0001] The present application relates to the field of motor vehicle accessories, in particular to an electronic water pump for an engine.BACKGROUND ART

[0002] With the increasing demand for energy conservation and environmental protection of automobiles, electronic water pumps have gradually replaced mechanical water pumps as the cooling water pumps for mainstream automobiles.

[0003] The structures of electric water pumps currently available on the market are becoming increasingly similar, and the structures of rotors generally adopt a wet-type design. In order to ensure sealing, the processes are typically complex, involving a great number of parts and high costs, which is disadvantageous to the general trend of cost reduction and efficiency improvement in the automobile market.

[0004] For example, FIG. 1 shows an electronic water pump in the prior art, which comprises a cover plate 1, a controller 2, a housing 3, an isolation sleeve 4, a stator 5, a sealing ring 6, a bearing seat 7, a volute 8, an impeller 9, a rotating shaft 10, a thrust bearing 11, a rotor 12, a graphite bearing 13, a thermal conductive adhesive 14, and a screw 15.

[0005] Such an electronic water pump has the following deficiencies:

[0006] (1) The heat dissipation of the controller depends on a separate flow channel, which splits the flow for heat dissipation. The loss in hydraulic efficiency is large, and the heat dissipation efficiency is low, resulting in low power density and large volume of the motor.

[0007] (2) The structure is complex, space utilization in an axial direction is low, and the size of the bearing is large.

[0008] (3) Both the stator and the rotor need to be equipped with an isolation sleeve so as to be sealed against water, and there are quite a number of other parts, such as sealing rings, resulting in a complex assembly process, high costs, and a high probability of sealing failure.

[0009] (4) Conventional screw-based installation is employed, which incurs high costs.

[0010] In addition, there are also solutions in the prior art in which the stator or the rotor is configured as an injection-molded member. However, the injection-molded members of these solutions suffer from a low level of integration, and one or more of the above-mentioned problems are still present.SUMMARY OF THE INVENTION

[0011] The objective of the present application is to overcome or at least alleviate the above-mentioned deficiencies of the prior art by providing an electronic water pump.

[0012] The present application provides an electronic water pump, the water pump comprising a stator assembly, a rotor assembly, and an impeller assembly, wherein

[0013] the stator assembly comprises a stator core and a stator injection-molded layer, and the stator injection -molded layer encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core,

[0014] the impeller assembly comprises an impeller and a volute that encloses the impeller,

[0015] the stator injection-molded layer and the volute are welded together by means of fusion; the electronic water pump further comprises a controller and a heat dissipation plate, and the volute further encloses the controller and the heat dissipation plate.

[0016] In at least one embodiment, the rotor assembly comprises a rotor core, a shaft, a thrust bearing, and a rotor injection-molded layer,

[0017] the rotor injection-molded layer encloses the rotor core, and the rotor injection- molded layer surrounds an axial gap between the thrust bearing and the shaft.

[0018] In at least one embodiment, one axial end portion of the rotor core is formed with a first recessed portion at an inner circumferential side, and a bearing sleeved around an end portion of the shaft is partially accommodated in the first recessed portion.

[0019] In at least one embodiment, the other axial end portion of the rotor core is formed with a second recessed portion at the inner circumferential side, and the thrust bearing partially extends into the second recessed portion.

[0020] In at least one embodiment, in an axial direction of the electronic water pump, the controller is disposed between the stator assembly and the impeller assembly.

[0021] In at least one embodiment, the stator injection -molded layer and the controller are respectively formed with structures used for mutual insertion, and the stator injection- molded layer and the controller, after being mutually inserted, are connected together by a hot riveting process.

[0022] In at least one embodiment, the heat dissipation plate is disposed between the controller and the impeller assembly.

[0023] In at least one embodiment, the heat dissipation plate is ring-shaped and comprises a main body ring, an outer circumferential wall, and inner circumferential wall, the outer circumferential wall is provided at an outer circumferential side of the main body ring, and the inner circumferential wall is provided at an inner circumferential side of the main body ring, such that the main body ring, the outer circumferential wall, and the inner circumferential wall form a ring-shaped, semi-open enclosure space, and

[0024] the controller is at least partially disposed inside the enclosure space.

[0025] In at least one embodiment, a first sealing ring is provided between the outer circumferential wall and the volute, and a second sealing ring is provided at an inner circumferential side of the inner circumferential wall.

[0026] In at least one embodiment, the stator assembly further comprises a cover plate, the cover plate is disposed at an end portion of the stator assembly facing away from the impeller assembly, and the cover plate and the stator injection-molded layer are joined together by means of fusion welding.

[0027] The electronic water pump according to the present application allows components thereof to be integrated into multiple injection-molded members, achieving structural simplicity and compactness, easy assembly, and good sealing performance.

[0028] The electronic water pump according to the present application can also be designed as an electronic oil pump. The electronic oil pump comprises essentially the features disclosed with regard to the electronic oil pump. However, instead of an impeller assembly comprising an impeller and a volute that encloses the impeller, the oil pump comprises a Gerotor assembly comprising an inner rotor and an outer rotor in mesh with the inner rotor, wherein the volute is designed as a pump housing section that encloses both the inner rotor and the outer rotor.

[0029] According to one aspect of the invention, the present application also provides a stator assembly for an electronic water pump and / or an oil pump. The stator assembly may comprise features described in relation to the electronic water pump.

[0030] According to one aspect of the invention, the present application provides an assembly, in particular for an electronic water pump and / or an electronic oil pump. The assembly comprises a stator assembly and a volute. The stator assembly comprises a stator core and a stator injection -molded layer, and the stator injection-molded layer encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core, the stator injection-molded layer and the volute are welded together by means of fusion. In a preferred embodiment, the assembly further comprises a controller and a heat dissipation plate, wherein the volute further encloses the controller and the heat dissipation plate.BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 shows a sectional view of a possible electronic water pump in the prior art.

[0032] FIG. 2 shows a sectional view of an electronic water pump according to an embodiment of the present application.

[0033] FIG. 3 shows a sectional view of a stator assembly of the electronic water pump according to the embodiment of the present application.

[0034] FIG. 4 shows a schematic view of a partial structure of the electronic water pump at a connection terminal according to the embodiment of the present application.

[0035] FIG. 5 shows a sectional view of a rotor assembly of the electronic water pump according to the embodiment of the present application.

[0036] Legend of reference signs:

[0037] S stator assembly; SO stator injection-molded layer; SOI spacer plate structure; SOI 1 central cylinder; S012 inner-side retaining ring; SOI 3 outer-side retaining ring; S02 clamping opening; S03 guide post; S04 recessed groove; SI stator core;

[0038] R rotor assembly; R0 rotor injection-molded layer; R1 rotor core; Ria first recessed portion; Rib second recessed portion;

[0039] R2 shaft; R3 thrust bearing;

[0040] T impeller assembly; TO volute; T1 impeller;

[0041] C controller; W wire; N connector; G thermal conductive adhesive;

[0042] P heat dissipation plate; Pl main body ring; P2 outer circumferential wall; P3 inner circumferential wall;

[0043] H cover plate; Hl flange; H2 protrusion;

[0044] Bl first bearing; B2 second bearing; LI first connection terminal; L2 second connection terminal; L21 first connection end; L22 second connection end; L3 fixing terminal.DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

[0045] An exemplary embodiment of the present application will be described below with reference to the drawings. It should be understood that the specific description is merely intended to teach those skilled in the art howto implement the present application, and is neither intended to exhaust all feasible implementations of the present application nor intended to limit the scope of the present application.

[0046] Referring to FIGS. 2-5, an electronic water pump according to an embodiment of the present application will be described.

[0047] Referring to FIG. 2, the electronic water pump according to the present application comprises a stator assembly S, a rotor assembly R, an impeller assembly T, a controller C, a heat dissipation plate P, a cover plate H, and a connector N. In an axial direction of the stator assembly S, the impeller assembly T is disposed at a first end portion of the stator assembly S (hereinafter, the end portion of the stator assembly S facing away from the impeller assembly T is referred to as a second end portion), and the controller C is disposed between the impeller assembly T and the stator assembly S. For convenience of description, hereinafter, according to the definition of the first end portion and second end portion of the stator assembly S, end portions of other members facing the same direction as the first end portion of the stator assembly S are also referred to as first end portions, and end portions thereof facing the same direction as the second end portion of the stator assembly S are also referred to as second end portions.

[0048] Meanwhile, referring to FIG. 3, the stator assembly S comprises a stator core SI, a stator injection-molded layer SO, a first bearing Bl, and insertion-connection members. The insertion-connection members comprise a first connection terminal LI used for connecting the controller C to an external insertion-connection member, and a second connection terminal L2 used for connecting the controller C to a stator winding.

[0049] The stator injection -molded layer SO encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core SI,thereby forming a sealing structure over the surface of the stator core SI. The thinnest portion of the stator injection-molded layer SO is located at the inner circumferential side of the stator core SI, and the thickness of said portion of the injection-molded layer is, e.g., from 0.4 mm to 0.8 mm.

[0050] At the first end portion of the stator assembly S, the stator injection-molded layer SO extends to the inner circumferential side of the stator core SI to form a coverlike spacer plate structure SOI. A central portion of the spacer plate structure SOI is penetrated in an axial direction to form a central cylinder SOU. A first bearing Bl is disposed at an inner side of the central cylinder SOU. The first bearing Bl is, e.g., a sliding bearing, further, e.g., a graphite bearing. The first bearing Bl may be integrally injection-molded with the central cylinder SOI 1 by means of a mold during formation of the stator injection -molded layer SO. The first bearing Bl is configured to be sleeved around an outer circumference of a shaft R2 to be described hereinafter. The stator injection-molded layer SO is formed with two concentric retaining rings spaced apart from each other (i.e., an inner retaining ring SOI 2 and an outer retaining ring SO 13) at an outer circumferential side of the central cylinder SOU. An annular recessed groove formed between the inner retaining ring S012 and the outer retaining ring SOI 3 is used for engaging with a heat dissipation plate P to be described hereinafter.

[0051] The first end portion of the stator assembly is further provided with insertionconnection members, i.e. the first connection terminal LI and the second connection terminal L2. The first connection terminal LI and the second connection terminal L2 are metal members. Referring to FIG. 4, in order to facilitate the installation of the first connection terminal LI and the second connection terminal L2, the stator injection- molded layer SO is formed with a notched clamping opening S02 at the first end portion. The clamping opening S02 is provided, in the middle of a bottom portion thereof, with a guide post S03 projecting toward the first end portion.

[0052] It should be understood that FIG. 4 is described by taking the second connection terminal L2 as an example, but the structure of the first connection terminalLI for connecting with the stator injection -molded layer SO is similar to that of the second connection terminal L2. Taking the second connection terminal L2 as an example, the second connection terminal L2 comprises a first connection end L21 and a second connection end L22. The first connection end L21 has an eye-of the-needle structure, and is configured to be inserted into an electrical connection port of the controller. The second connection end L22 comprises two insertion-connection legs that are spaced apart from each other. The distance between the two insertion-connection legs at end portions thereof is greater than the diameter of a wire W, and the distance between the two insertionconnection legs gradually decreases in the direction towards the first connection end L21 until it is smaller than the diameter of the wire W. Such a structural design enables an insulating layer (also called varnish) of an outer layer of the wire W to be damaged by the two insertion-connection legs during the insertion of the wire W into the insertionconnection legs, such that the wire W forms an electrical connection with the insertionconnection legs. Moreover, the two insertion-connection legs can clamp the wire W tightly, eliminating the need for welding between the wire W and the second connection end L22.

[0053] The second connection end L22 can be inserted into the clamping opening S02, forming an interference fit therebetween. The wire W clamped between the two insertionconnection legs abuts and contacts the guide post S03.

[0054] At the second end portion of the stator assembly S, the stator injection-molded layer SO is formed with an annular recessed groove S04, which is used for engaging with the cover plate H to be described hereinafter.

[0055] The connector N is disposed on the outer circumferential side of the stator core SI. A housing of the connector N is also integrally formed with the stator assembly S during injection molding of the stator injection -molded layer SO. In other words, part of the structure of the stator injection-molded layer SO also constitutes the housing of the connector N.

[0056] The stator assembly S is fixed, at the first end portion thereof, to the impeller assembly T.

[0057] The impeller assembly T comprises an impeller T1 and a volute TO. The impeller T1 is sleeved around the first end portion of the shaft R2. The volute TO is an injection-molded member, and optionally, the volute TO is made of the same material as that of the stator injection-molded layer SO. The volute TO covers the first end portion of the stator assembly S, and the volute TO and the stator injection-molded layer SO may be joined together by means of fusion welding. In the present embodiment, an edge of the volute TO surrounds the stator injection-molded layer SO at a connection location between the volute TO and the stator injection-molded layer SO.

[0058] In addition to the impeller Tl, the controller C and the heat dissipation plate P are also accommodated within the volute TO. In the axial direction, the heat dissipation plate P is closer to the impeller Tl than the controller C is.

[0059] The heat dissipation plate P is ring-shaped and comprises a main body ring Pl , an outer circumferential wall P2, and an inner circumferential wall P3. The outer circumferential wall P2 and the inner circumferential wall P3 each form a flanged structure that extends in the axial direction, such that the cross-section of the heat dissipation plate P on an axial side is substantially C-shaped. An end portion of the inner circumferential wall P3 extends into the annular recessed groove between the inner retaining ring S012 and the outer retaining ring S013 as described above. The outer circumferential wall P2 abuts against an end surface of the stator injection layer SO at the first end portion. A first sealing ring El is provided between an outer circumferential side of the outer circumferential wall P2 and the volute TO, and a second sealing ring E2 is provided between an inner side of the inner circumferential wall P3 and the central cylinder SOU of the stator injection-molded layer SO. The above structure enables the spacer plate structure SOI to function as an isolation sleeve in the prior art, ensuring that a cooling liquid at the side of the impeller Tl is isolated from the side where a motor islocated. Optionally, the heat dissipation plate P is made of a metal material, such as aluminum or aluminum alloy.

[0060] The controller C is disposed within a semi-enclosed annular space defined by the heat dissipation plate P. A thermal conductive adhesive G is provided between the controller C and the heat dissipation plate P.

[0061] In order to enhance the positioning of the controller C, the controller C is further joined to the stator injection-molded layer SO of the stator assembly S by means of fusion welding. The stator injection -molded layer SO is formed with a short cylindrical fixing terminal L3 at the first end portion of the stator assembly S, and the end face of the controller C facing the stator assembly S is formed with a corresponding recessed portion (not shown). The fixing terminal L3 can be inserted into the recessed portion of the controller C and fixedly connected to the controller C by means of, e.g., a hot riveting process.

[0062] Next, the rotor assembly R will be described by referring to FIG. 5. The rotor assembly R comprises a rotor core Rl, a shaft R2, a thrust bearing R3, and a rotor injection-molded layer R0.

[0063] The shaft R2 is fixed at an inner circumference of the rotor core Rl in a manner such that it is not rotatable relative to the rotor core Rl . The shaft R2 is provided with the thrust bearing R3. In the axial direction of the rotor assembly R, the thrust bearing R3 is located at an end portion of the rotor core Rl adjacent to the first end portion.

[0064] The rotor injection -molded layer R0 encapsulates an outer circumferential side and two axial end portions of the rotor core Rl . Moreover, at the first end portion, the rotor injection-molded layer R0 surrounds an axial gap between the thrust bearing R3 and the shaft R2, and at the second end portion, the rotor injection layer R0 surrounds an axial gap between the rotor core Rl and the shaft R2.

[0065] In the present embodiment, each of the axial ends of the rotor core Rl is partially recessed at an inner circumferential region thereof, forming a first recessedportion Ria and a second recessed portion Rib, respectively. At the first end portion, the second recessed portion Rib enables the thrust bearing R3 to partially extend therein. At the first end portion, the first recessed portion Ria enables a second bearing B2, which is to be described hereinafter, to partially extend thereinto. This solution shortens the overall size of the motor in the axial direction.

[0066] Referring back to FIG. 2, when the rotor assembly R is inserted into the stator assembly S and the two assemblies are fully assembled, the cover plate H is placed at the second end portion of the stator assembly S to seal the end portion.

[0067] A main body of the cover plate H is made of plastics. Optionally, the cover plate H is made of the same material as that of the stator injection-molded layer SO. An outer circumference of the cover plate H is formed with an annular flange Hl that extends in the axial direction. The outer diameter of the flange Hl is substantially equal to the outer diameter of the recessed groove S04 of the stator injection-molded layer SO, and the inner diameter of the flange Hl is substantially equal to the inner diameter of the recessed groove S04. When the cover plate H engages with the stator assembly S, the flange Hl extends into the recessed groove S04. When the cover plate H covers the second end portion of the stator assembly S, the flange Hl and the stator injection-molded layer SO may be connected together by means of fusion welding.

[0068] A central portion of a side of the cover plate H facing the stator assembly S partially protrudes to form a protrusion H2. The second bearing B2 is fixed inside the protrusion H2. The second bearing B2 is, e.g., a sliding bearing, further, e.g., a graphite bearing. The second bearing B2 may be integrally formed with the protrusion H2 by means of a mold during injection molding of the cover plate H.

[0069] The present application has at least one of the following advantages:

[0070] (i) Both the rotor assembly and the stator assembly have integral injection- molded structures, which simplifies the assembly process and provides good sealing performance.

[0071] (ii) The rotor injection-molded member is configured such that the rotor core and the thrust bearing are integrally injection-molded and sealed, which reduces the axial length, reduces the number of parts, and saves extra costs for sealing. The stator injection- molded member is configured such that the stator, the original housing, the insertionconnection members, the original isolation sleeve, and the graphite bearing are integrally injection-molded, eliminating the original isolation sleeve while making the overall spatial structure more compact and significantly reducing the volume.

[0072] (iii) The controller is disposed between the motor and a flow path, and the heat dissipation plate and the thermal conductive adhesive are provided therebetween. As such, there is no need for an additional flow path for heat dissipation, the loss in fluid efficiency is small, and the cooling performance of the controller is improved, increasing the power density of the motor and accordingly reducing the overall volume of the water pump.

[0073] (iv) The connection between the volute and the stator injection -molded layer, the connection between the stator injection-molded layer and the cover plate, and the connection between the controller and the stator assembly are all implemented by means of plastic fusion welding. As such, not a single screw is needed for the entire pump, which reduces costs.

[0074] (v) The varnished copper wire of the stator is inserted into the injection-molded stator by using a terminal that mechanically strips the varnish, which eliminates the need for welding. The terminal and the controller are connected by means of an eye-of the- needle structure, which eliminates the need for welding and reduces process costs.

[0075] (vi) The overall structure is simple and reliable. The number of the sealing rings is reduced from the original four to two, and the probability of sealing failure is greatly reduced.

[0076] Of course, the present application is not limited to the above-described embodiment, and various modifications may be made to the above-described embodimentof the present application by those skilled in the art in light of the teachings of the present application without departing from the scope of the present application.

Claims

CLAIMS1. An electronic water pump, the water pump comprising a stator assembly (S), a rotor assembly (R), and an impeller assembly (T), characterized in that: the stator assembly (S) comprises a stator core (SI) and a stator injection-molded layer (SO), and the stator injection-molded layer (SO) encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core (SI), the impeller assembly (T) comprises an impeller (Tl) and a volute (TO) that encloses the impeller (Tl), the stator injection-molded layer (SO) and the volute (TO) are welded together by means of fusion; the electronic water pump further comprises a controller (C) and a heat dissipation plate (P), and the volute (TO) further encloses the controller (C) and the heat dissipation plate (P).

2. The electronic water pump according to claim 1, wherein the rotor assembly (R) comprises a rotor core (Rl), a shaft (R2), a thrust bearing (R3), and a rotor injection- molded layer (RO), the rotor injection-molded layer (RO) encloses the rotor core (Rl), and the rotor injection-molded layer (RO) surrounds an axial gap between the thrust bearing (R3) and the shaft (R2).

3. The electronic water pump according to claim 2, wherein one axial end portion of the rotor core (Rl) is formed with a first recessed portion (Ria) at an inner circumferential side, and a bearing sleeved around an end portion of the shaft (R2) is partially accommodated in the first recessed portion (Ria).

4. The electronic water pump according to one of claims 2 or 3, wherein the other axial end portion of the rotor core (Rl) is formed with a second recessed portion (Rib) at the inner circumferential side, and the thrust bearing (R3) partially extends into the second recessed portion (Rib).

5. The electronic water pump according to one of claims 1 to 4, wherein in an axial direction of the electronic water pump, the controller (C) is disposed between the stator assembly (S) and the impeller assembly (T).

6. The electronic water pump according to one of claims 1 to 5, wherein the stator injection-molded layer (SO) and the controller (C) are respectively formed with structures used for mutual insertion, and the stator injection-molded layer (SO) and the controller (C), after being mutually inserted, are connected together by means of a hot riveting process.

7. The electronic water pump according to one of claims 1 to 6, wherein the heat dissipation plate (P) is disposed between the controller (C) and the impeller assembly (T).

8. The electronic water pump according to one of claims 1 to 7, wherein the heat dissipation plate (P) is ring-shaped and comprises a main body ring (Pl), an outer circumferential wall (P2), and an inner circumferential wall (P3), the outer circumferential wall (P2) is provided at an outer circumferential side of the main body ring (Pl), and the inner circumferential wall (P3) is provided at an inner circumferential side of the main body ring (Pl), such that the main body ring (Pl), the outer circumferential wall (P2), and the inner circumferential wall (P3) form a ring-shaped, semi-open enclosure space, and the controller (C) is at least partially disposed inside the enclosure space.

9. The electronic water pump according to one of claims 1 to 8, wherein a first sealing ring (El) is provided between the outer circumferential wall (P2) and the volute (TO), and a second sealing ring (E2) is provided at an inner circumferential side of the inner circumferential wall (P3).

10. The electronic water pump according to one of claims 1 to 9, wherein the stator assembly (S) further comprises a cover plate (H), the cover plate (H) is disposed at an end portion of the stator assembly (S) facing away from the impeller assembly (T), and the cover plate (H) and the stator injection-molded layer (SO) are joined together by means of fusion welding.

11. Stator assembly (S) for an electronic water pump according to one of the claims 1 to 10.

12. Assembly, in particular for an electronic water pump and / or an electronic oil pump, comprising a stator assembly (S) and a volute (TO), characterized in that: the stator assembly (S) comprises a stator core (SI) and a stator injection-molded layer (SO), and the stator injection-molded layer (SO) encapsulates an inner circumferential side, an outer circumferential side, and two axial end portions of the stator core (SI), the stator injection-molded layer (SO) and the volute (TO) are welded together by means of fusion; wherein in particular the assembly further comprises a controller (C) and a heat dissipation plate (P), and the volute (TO) further encloses the controller (C) and the heat dissipation plate (P).

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