Shaft sleeve, rotor assembly and electronic water pump applying same

Abstract

The utility model discloses a shaft sleeve, a rotor assembly and an electronic water pump using the same, and relates to the technical field of electronic water pumps and parts of the electronic water pumps, rotation stopping reinforcing ribs are formed on the outer side face of the shaft sleeve and used for improving the mechanical strength of the shaft sleeve, and the rotation stopping reinforcing ribs are further used for being matched with a rotor support of the rotor assembly. And the shaft sleeve and the rotor bracket do not rotate relatively. The utility model mainly solves the problem of how to provide a reasonable and reliable rotation stopping structure for the shaft sleeve of the rotor assembly. According to the shaft sleeve, the rotor assembly and the electronic water pump applying the shaft sleeve, the rotation stopping reinforcing ribs are formed on the outer side face of the shaft sleeve, the mechanical strength of the shaft sleeve can be improved, the shaft sleeve can be matched with the rotor support of the rotor assembly, the shaft sleeve and the rotor support cannot rotate relatively, and therefore the shaft sleeve has a reasonable and reliable rotation stopping structure; compared with a rotation stopping concave position obtained by machining the surface of the shaft sleeve, the shaft sleeve is not prone to being damaged, and the yield of the electronic water pump is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic water pumps and their components, and specifically to a shaft sleeve, a rotor assembly, and an electronic water pump applying the same. Background Technique

[0002] A water pump can drive the flow of liquid, enabling the liquid to flow directionally from one place to another, and it is a mechanical device with a wide range of uses.

[0003] An electronic water pump is an important type of water pump. Among them, the rotor assembly is one of the core components of the electronic water pump; in the existing electronic water pumps, the rotor assembly usually integrates a magnetic ring and an impeller on the rotor bracket. The magnetic ring can rotate in the rotating magnetic field generated by the stator assembly of the electronic water pump, thereby driving the entire rotor bracket and impeller to rotate. The rotating impeller can drive the liquid to flow, thus realizing the basic function of the water pump.

[0004] The Chinese utility model patent with the publication number CN220470281U and the name "Rotor Assembly and Electronic Water Pump Applying the Same" discloses a typical rotor assembly structure.

[0005] For the rotor assembly applied in an electronic water pump, a shaft sleeve (bearing) is used as a rotating support member inside it. Specifically, a sintered shaft sleeve with a relatively high cost is used. It is placed together with the magnetic ring into the injection mold of the rotor bracket, and through the method of integral injection molding, the shaft sleeve, the magnetic ring, and the rotor bracket are formed into one body to form a rotor assembly with an integral structure.

[0006] When manufacturing the sintered shaft sleeve, there is no anti-rotation structure designed in its process. Therefore, after the sintered shaft sleeve is formed, one or more concave structures need to be obtained through machining for anti-rotation.

[0007] However, the sintered shaft sleeve has a relatively high hardness but is relatively fragile. Machining the sintered shaft sleeve will increase the risk of its cracking, resulting in a series of problems such as the performance degradation of the rotor assembly and the electronic water pump, and the scrapping of the sintered shaft sleeve.

[0008] In summary, how to provide a reasonable and reliable anti-rotation structure for the shaft sleeve of the rotor assembly has become one of the problems to be solved urgently. Content of the Utility Model

[0009] The purpose of the utility model is to provide a shaft sleeve, a rotor assembly, and an electronic water pump applying the same, and the shaft sleeve thereof has a reasonable and reliable anti-rotation structure.

[0010] To achieve the above object, the present utility model provides the following technical solution: a shaft sleeve, which is applied in a rotor assembly; the shaft sleeve is provided with a shaft hole axially penetrating through itself; a rotation-preventing reinforcing rib is formed on the outer side surface of the shaft sleeve, the rotation-preventing reinforcing rib is used to improve the mechanical strength of the shaft sleeve, and the rotation-preventing reinforcing rib is also used to cooperate with a rotor bracket of the rotor assembly so that the shaft sleeve and the rotor bracket do not rotate relative to each other.

[0011] In the above technical solution, the cross-sectional shape of the rotation-preventing reinforcing rib in the axial direction is one of a square, a circle, an ellipse, a polygon, and an irregular shape.

[0012] In the above technical solution, the length of the shaft sleeve is H, and the axial length of the rotation-preventing reinforcing rib is L, then: 8 mm ≤ L ≤ 3 4H.

[0013] In the above technical solution, the inner wall of the shaft hole is concave inward in the radial direction to form a flow-through groove axially penetrating through the shaft sleeve; when the shaft sleeve is sleeved on a shaft core, liquid can flow along the flow-through groove of the shaft sleeve.

[0014] A rotor assembly, which includes the above-mentioned shaft sleeve; it further includes a rotor bracket, a magnetic ring, and an impeller; the rotor bracket is integrally injection-molded and combined with the shaft sleeve and the magnetic ring respectively, so that the shaft sleeve is arranged in the rotor bracket, and the magnetic ring is sleeved outside the rotor bracket; the rotation-preventing reinforcing rib of the shaft sleeve is embedded into the inner wall of the rotor bracket so that the shaft sleeve and the rotor bracket do not rotate relative to each other; the impeller is fixed on the rotor bracket.

[0015] In the above technical solution, the outer diameter of the shaft sleeve at the rotation-preventing reinforcing rib is D1, and the inner diameter of the magnetic ring is D2, then: D1 < 2 3D2.

[0016] In the above technical solution, one end of the rotor bracket expands in the radial direction to form an impeller mounting platform; the impeller is fixed on the impeller mounting platform of the rotor bracket by ultrasonic welding.

[0017] An electronic water pump, which includes the above-mentioned rotor assembly.

[0018] In the above technical solution, the electric water pump of the present utility model further includes a pump cover, a pump chamber structure housing, a stator-pump housing assembly, a drive circuit board, a rear end cover, and a shaft core; after the pump cover and the pump chamber structure housing are fixedly combined with each other, a pump chamber structure is formed; a water inlet and a water outlet for communicating the inside and outside of the pump chamber structure are respectively formed on the pump cover; one end of the shaft core is fixedly fitted with the pump chamber structure housing, and the other end of the shaft core is fixedly fitted with the pump cover to support the shaft core in the pump chamber structure; the shaft sleeve of the rotor assembly is sleeved on the shaft core and is rotationally fitted with the shaft core; the stator-pump housing assembly includes a pump housing and a stator assembly, and the pump housing is formed outside the stator assembly in a coated molding manner, so that the stator assembly is buried in the pump housing; the pump cover, the pump chamber structure housing, and the pump housing of the stator-pump housing assembly are fixedly arranged in sequence along the axial direction, so that the stator assembly of the stator-pump housing assembly is radially aligned with the magnetic ring of the rotor assembly; the drive circuit board is accommodated and fixed in the pump housing, and the end cover is fixed at one end of the pump housing and covers the opening of the pump housing; the drive circuit board is electrically connected to the stator assembly of the stator-pump housing assembly, so that the stator assembly can magnetically couple and drive the rotor assembly to rotate around the shaft core in the pump chamber structure.

[0019] In the above technical solution, in the shaft sleeve of the rotor assembly: the inner wall of the shaft hole is concave inward in the radial direction to form a flow-through groove axially penetrating the shaft sleeve; when the shaft sleeve of the rotor assembly is sleeved on the shaft core, liquid can flow along the flow-through groove of the shaft sleeve.

[0020] Compared with the prior art, the beneficial effects of the present utility model are as follows: for the shaft sleeve, rotor assembly and the electric water pump applying the same of the present utility model, the outer side surface of the shaft sleeve is formed with anti-rotation reinforcing ribs, which can improve the mechanical strength of the shaft sleeve and can also cooperate with the rotor bracket of the rotor assembly (i.e., be embedded in the inner wall of the rotor bracket), so that the shaft sleeve and the rotor bracket will not rotate relatively, thereby enabling the shaft sleeve to have a reasonable and reliable anti-rotation structure. Compared with obtaining an anti-rotation concave position by machining the surface of the shaft sleeve, the shaft sleeve of the present utility model is less likely to be damaged, and the yield rate of the electric water pump is improved. Description of the Drawings

[0021] Figure 1 It is a three-dimensional view of the shaft sleeve in the present utility model.

[0022] Figure 2 It is a sectional view of the shaft sleeve in the present utility model.

[0023] Figure 3 It is a three-dimensional view of the rotor assembly in the present utility model.

[0024] Figure 4 It is an exploded view of the rotor assembly in the present utility model.

[0025] Figure 5 This is a cross-sectional view of the rotor assembly in the present utility model.

[0026] Figure 6 This is a three-dimensional view of the electronic water pump in the present utility model.

[0027] Figure 7 This is an exploded view of the electronic water pump in the present utility model.

[0028] Figure 8 This is a cross-sectional view of the electronic water pump in the present utility model.

[0029] Figure 9 This is a cross-sectional view of the pump chamber structure in the present utility model.

[0030] The reference numerals are: 1, shaft sleeve; 11, shaft hole; 111, flow-through groove; 12, anti-rotation reinforcing rib; 2, rotor assembly; 21, rotor bracket; 211, impeller mounting table; 22, magnetic ring; 23, impeller; 3, pump cover; 31, shaft core seat; 32, water inlet; 33, water outlet; 4, pump chamber structure housing; 41, bottom plate; 5, stator-pump housing assembly; 51, pump housing; 52, stator assembly; 6, drive circuit board; 7, rear end cover; 8, shaft core; 10, pump chamber structure. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0032] This embodiment provides a shaft sleeve, which is applied in the rotor assembly and is used as a rotating support member of the rotor assembly (i.e., its function is roughly the same as that of a bearing).

[0033] Please refer to Figure 1 and Figure 2 , the shaft sleeve 1 of this embodiment is provided with a shaft hole 11 that axially penetrates itself. The shaft hole 11 is a cylindrical hole for the shaft core 8 of the electronic water pump to penetrate into it.

[0034] The outer side surface of the shaft sleeve 1 is formed with an anti-rotation reinforcing rib 12. The anti-rotation reinforcing rib 12 is used to improve the mechanical strength of the shaft sleeve 1, and the anti-rotation reinforcing rib 12 is also used to cooperate with the rotor bracket 21 of the rotor assembly 2 so that the shaft sleeve 1 and the rotor bracket 21 will not rotate relative to each other.

[0035] It should be noted that the bushing 1 in this embodiment is specifically a sintered bushing, that is, made of ceramic material. Its shaft hole 11 and anti-rotation reinforcing rib 12 are both features integrally formed on the bushing 1. Among them, the anti-rotation reinforcing rib 12 is a convex structure integrally formed on the outer side surface of the bushing 1, and is sintered together with the body of the bushing 1. In this embodiment, there are 4 anti-rotation reinforcing ribs 12. In other embodiments, the anti-rotation reinforcing rib 12 can be set to 1, 2, 3, 5, 6 or more. The anti-rotation reinforcing ribs 12 should generally be evenly distributed circumferentially along the outer side surface of the bushing 1.

[0036] Specifically, the cross-sectional shape of the anti-rotation reinforcing rib 12 in the axial direction is one of a square, a circle, an ellipse, a polygon, and an irregular shape. Among them, the cross-section in the axial direction specifically refers to the cross-section that is in the axial direction of the bushing 1 and horizontally passes through the anti-rotation reinforcing rib 12. In this embodiment, the cross-sectional shape of the anti-rotation reinforcing rib 12 in the axial direction is a square, so that the overall outer contour of the anti-rotation reinforcing rib 12 is square.

[0037] As Figure 2 shown, further, the length of the bushing 1 is H, and the axial length of the anti-rotation reinforcing rib 12 is L, then: 8mm ≤ L ≤ 3 4H; with this setting, the anti-rotation reinforcing rib 12 has sufficient axial length, so as to fully cooperate with the rotor bracket 21 and obtain sufficient anti-rotation performance.

[0038] Further, the inner wall of the shaft hole 11 is concave inward in the radial direction to form a flow-through groove 111 that axially penetrates the bushing 1. Among them, the flow-through groove 111 is also a feature integrally formed on the bushing 1, and is sintered together with the body of the bushing 1. In this embodiment, the bottom of the flow-through groove 111 is arc-shaped. When the bushing 1 is sleeved on the shaft core 8, the liquid can flow along the flow-through groove 111 of the bushing 1.

[0039] This embodiment also provides a rotor assembly 2, which is applied in an electronic water pump and is used as a fluid power driving component of the electronic water pump.

[0040] Please refer to Figures 3 - 5 , the rotor assembly 2 of this embodiment includes the above-mentioned bushing 1, and it also includes a rotor bracket 21, a magnetic ring 22, and an impeller 23.

[0041] Among them, the rotor bracket 21 is an integrally injection-molded annular bracket, which is used to provide an overall support basis for the rotor assembly 2; the magnetic ring 22 is a magnetic metal ring body, which can be magnetically coupled with the stator assembly 52 to drive the rotation of the rotor assembly 2; the impeller 23 is an integrally injection-molded engineering plastic component, which has a number of blades and is used to drive the liquid to flow when rotating.

[0042] The rotor bracket 21 is integrally injection-molded and combined with the shaft sleeve 1 and the magnetic ring 22 respectively to form a single body, such that the shaft sleeve 1 is inserted into the rotor bracket 21, and the magnetic ring 22 is sleeved outside the rotor bracket 21; the anti-rotation reinforcing ribs 12 of the shaft sleeve 1 are embedded into the inner wall of the rotor bracket 21, so that the shaft sleeve 1 and the rotor bracket 21 will not rotate relative to each other; when manufacturing the rotor assembly 2 of this embodiment, the shaft sleeve 1 and the magnetic ring 22 are respectively placed into the mold of the rotor bracket 21, and the rotor bracket 21 is formed by integral injection molding. After the rotor bracket 21 is formed, it is combined with the shaft sleeve 1 and the magnetic ring 22 to form a single body. At this time, the anti-rotation reinforcing ribs 12 of the shaft sleeve 1 are embedded into the inner wall of the rotor bracket 21.

[0043] The impeller 23 is fixed on the rotor bracket 21. Specifically, one end of the rotor bracket 21 expands in the radial direction to form an impeller mounting table 211. The impeller mounting table 211 is a flat plate-like structure integrally formed with the rotor bracket 21, and its surface is provided with embedding grooves matching the blades of the impeller 23. The impeller 23 is fixed on the impeller mounting table 211 of the rotor bracket 21 by ultrasonic welding, that is, each blade of the impeller 23 corresponds to and is embedded into each embedding groove of the impeller mounting table 211, and each blade of the impeller 23 is welded in each embedding groove of the impeller mounting table 211 by ultrasonic welding, thereby realizing the fixation of the impeller 23 and the rotor bracket 21.

[0044] Further, the outer diameter of the shaft sleeve 1 at the anti-rotation reinforcing ribs 12 is D1, and the inner diameter of the magnetic ring 22 is D2, then: D1 < 2 3D2; with this setting, the matching thickness between the anti-rotation reinforcing ribs 12 and the rotor bracket 21 can be controlled. On the one hand, the rotor bracket 21 can obtain sufficient mechanical strength, and on the other hand, the anti-rotation reinforcing ribs 12 and the rotor bracket 21 can be fully matched to obtain sufficient anti-rotation performance.

[0045] This embodiment also provides an electronic water pump, which includes the above-mentioned rotor assembly 2.

[0046] Please refer to Figures 6 - 9 , the electronic water pump of this embodiment further includes a pump cover 3, a pump chamber structure housing 4, a stator-pump housing assembly 5, a drive circuit board 6, a rear end cover 7, and a shaft core 8.

[0047] Among them, the pump cover 3 is an integrally formed cover body of metal material or engineering plastic material, the pump chamber structure shell 4 is an integrally formed thin shell component of engineering plastic material, which can allow the magnetic field to pass through; the driving circuit board 6 is a printed circuit board (PCB), which is equipped with a main control, a stator drive module and necessary peripheral circuits for driving the stator assembly 52 to operate; the rear end cover 7 is a metal cover plate, used as one of the shielding and protection structures of the electronic water pump; the shaft core 8 is an integrally formed metal shaft, such as stainless steel or aluminum alloy.

[0048] After the pump cover 3 and the pump chamber structure shell 4 are fixedly combined with each other, a pump chamber structure 10 is formed. Specifically, the pump chamber structure shell 4 and the pump cover 3 are combined into one by screws or buckles, and are sealed by a sealing ring, so that the inner cavity of the pump chamber structure shell 4 and the inner cavity of the pump cover 3 are enclosed to form the pump chamber structure 10; a water inlet 32 ​​and a water outlet 33 connecting the inner and outer sides of the pump chamber structure 10 are respectively formed on the pump cover 3. In fact, the water inlet 32 ​​and the water outlet 33 are both hard short tubes integrally formed on the pump cover 3.

[0049] One end of the shaft core 8 is fixedly matched with the pump chamber structure shell 4, and the other end of the shaft core 8 is fixedly matched with the pump cover 3 to support the shaft core 8 in the pump chamber structure 10; in this embodiment, one end of the shaft core 8 is buried in the bottom plate 41 of the pump chamber structure shell 4 by integral injection molding, and a shaft core seat 31 is also formed on the inner side of the pump cover 3. The shaft core seat 31 is also integrally molded on the pump cover 3 and is located on the inner side of the water inlet 32. The other end of the shaft core 8 is inserted into the shaft core seat 31 of the pump cover 3, so that the other end of the shaft core 8 is supported by the shaft core seat 31 of the pump cover 3, thereby fixing both ends of the shaft core 8.

[0050] The shaft sleeve 1 of the rotor assembly 2 is sleeved on the shaft core 8 and rotatably cooperates with the shaft core 8 , in this way, the rotor assembly 2 is supported in the pump chamber structure 10 .

[0051] The stator-pump casing assembly 5 includes a pump casing 51 and a stator component 52, wherein the stator component 52 includes a stator core, an enameled wire coil wound on the stator core and distributed circumferentially, and a terminal plugged and fixed on the stator core and electrically connected to the end of the enameled wire coil; the pump casing 51 is formed outside the stator component 52 in an overmolding manner, so that the stator component 52 is buried in the pump casing 51. When manufacturing the stator-pump casing assembly 5, the stator component 52 is placed as a whole in a molding mold of the pump casing 51, and then plastic material is injected into the molding mold. After the plastic material is solidified, the pump casing 51 is formed. At this time, the stator component 52 and the pump casing 51 are molded as a whole to form the stator-pump casing assembly 5.

[0052] The pump cover 3, the pump chamber structure housing 4, and the pump housing 51 of the stator-pump housing assembly 5 are fixed in sequence along the axial direction (specifically fixed by screws), so that the stator assembly 52 of the stator-pump housing assembly 5 and the magnetic ring 22 of the rotor assembly 2 are aligned with each other in the radial direction. At this time, the magnetic ring 22 of the rotor assembly 2 is located inside the inner ring of the stator assembly 52, and the two can achieve magnetic coupling. A sealing ring is provided between the pump chamber structure housing 4 and the stator-pump housing assembly 5 to enhance the sealing degree inside the stator-pump housing assembly 5; the drive circuit board 6 is accommodated and fixed in the pump housing 51 (specifically fixed by screws), and the end cover is fixed to one end of the pump housing 51 and covers the opening of the pump housing 51 (specifically also fixed by screws). A sealing ring is provided between the end cover and the stator-pump housing assembly 5 to enhance the sealing degree inside the stator-pump housing assembly 5; the drive circuit board 6 is electrically connected to the stator assembly 52 of the stator-pump housing assembly 5, so that the stator assembly 52 can magnetically couple and drive the rotor assembly 2 to rotate around the shaft core 8 in the pump chamber structure 10. Specifically, the terminals of the stator assembly 52 are exposed outside the pump housing 51 (but located in the inner space of the pump housing 51) and are welded to the drive circuit board 6, thereby realizing the electrical connection between the drive circuit board 6 and the stator assembly 52, enabling the drive circuit board 6 to drive the stator assembly 52 to operate.

[0053] Furthermore, the inner wall of the shaft hole 11 is recessed inward in the radial direction to form an overflow groove 111 that axially penetrates the shaft sleeve 1; among them, this overflow groove 111 is also a feature integrally formed on the shaft sleeve 1, and it is sintered together with the body of the shaft sleeve 1. In this embodiment, the bottom of the overflow groove 111 is arc-shaped; when the shaft sleeve 1 of the rotor assembly 2 is sleeved on the shaft core 8, the liquid can flow along the overflow groove 111 of the shaft sleeve 1.

[0054] When the electronic water pump of this embodiment is in use, the drive circuit board 6 is powered on, and the coil of the stator assembly 52 is powered on through the terminals, so that a rotating magnetic field is formed in the space inside the inner ring of the stator assembly 52, thereby magnetically coupling with the magnetic ring 22 of the rotor assembly 2 to drive the entire rotor assembly 2 to rotate in the pump chamber structure 10; the impeller 23 during rotation can drive the liquid to flow along its blades, and the water flow enters the pump cover 3 from the water inlet 32 and flows toward the water outlet 33, that is, the basic function of the electronic water pump is realized; during the above process, the entire pump chamber structure 10 is filled with liquid, and these liquids may carry impurities. Due to the existence of the overflow groove 111, the liquid can flow along the overflow groove 111 of the shaft sleeve 1. On the one hand, it improves the liquid flow rate in the pump chamber structure 10, and on the other hand, the overflow groove 111 allows small particle impurities to pass through, avoiding excessive accumulation of impurities in the pump chamber structure 10 and the rotor assembly 2.

[0055] For the bushing, rotor assembly 2 and the electronic water pump applying the same in this embodiment, the outer side surface of the bushing 1 is formed with an anti-rotation reinforcing rib 12, which can improve the mechanical strength of the bushing 1 and can also cooperate with the rotor bracket 21 of the rotor assembly 2 (i.e., be embedded in the inner wall of the rotor bracket 21), so that the bushing 1 and the rotor bracket 21 will not rotate relative to each other, thereby enabling the bushing 1 to have a reasonable and reliable anti-rotation structure. Compared with obtaining an anti-rotation recess by machining the surface of the bushing 1, the bushing 1 in this embodiment is less likely to be damaged, improving the yield rate of the electronic water pump.

[0056] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bushing, which is applied in a rotor assembly; The bushing is provided with a shaft hole axially penetrating through itself; characterized in that, A rotation prevention reinforcing rib is formed on the outer side surface of the bushing, the rotation prevention reinforcing rib is used to improve the mechanical strength of the bushing, and the rotation prevention reinforcing rib is also used to cooperate with a rotor bracket of the rotor assembly, so that the bushing and the rotor bracket will not rotate relatively.

2. The bushing according to claim 1, characterized in that, The cross-sectional shape of the rotation prevention reinforcing rib in the axial direction is one of a square, a circle, an ellipse, and a polygon.

3. The bushing according to claim 1 or 2, characterized in that, The length of the bushing is H, and the axial length of the rotation prevention reinforcing rib is L, then there is:

4. The bushing according to claim 1, characterized in that, The inner wall of the shaft hole is concave inward in the radial direction, forming a flow-through groove axially penetrating through the bushing; When the bushing is sleeved on a shaft core, liquid can flow along the flow-through groove of the bushing.

5. A rotor assembly, characterized in that, Including the bushing according to any one of claims 1-4; It further includes a rotor bracket, a magnetic ring, and an impeller; The rotor bracket is integrally injection-molded and respectively combined with the bushing and the magnetic ring into one body, so that the bushing is arranged in the rotor bracket, and the magnetic ring is sleeved outside the rotor bracket; The rotation prevention reinforcing rib of the bushing is embedded into the inner wall of the rotor bracket, so that the bushing and the rotor bracket will not rotate relatively; The impeller is fixed on the rotor bracket.

6. The rotor assembly according to claim 5, characterized in that, The outer diameter of the bushing at the rotation prevention reinforcing rib is D1, and the inner diameter of the magnetic ring is D2, then there is:

7. The rotor assembly according to claim 5, characterized in that, One end of the rotor bracket expands in the radial direction to form an impeller mounting table; The impeller is fixed on the impeller mounting table of the rotor bracket by ultrasonic welding.

8. An electronic water pump, characterized in that, Including the rotor assembly according to any one of claims 5-7.

9. The electric water pump according to claim 8, wherein, It further includes a pump cover, a pump cavity structure housing, a stator-pump housing assembly, a drive circuit board, a rear end cover, and a shaft core; After the pump cover and the pump cavity structure housing are fixedly combined with each other, a pump cavity structure is enclosed; An inlet and an outlet for communicating the inside and outside of the pump cavity structure are respectively formed on the pump cover; One end of the shaft core is fixedly matched with the pump cavity structure housing, and the other end of the shaft core is fixedly matched with the pump cover to support the shaft core in the pump cavity structure; The bushing of the rotor assembly is sleeved on the shaft core and is rotationally matched with the shaft core; The stator-pump housing assembly includes a pump housing and a stator assembly, and the pump housing is formed outside the stator assembly by overmolding, so that the stator assembly is buried in the pump housing; The pump cover, the pump cavity structure housing, and the pump housing of the stator-pump housing assembly are fixedly arranged in sequence in the axial direction, so that the stator assembly of the stator-pump housing assembly and the magnetic ring of the rotor assembly are aligned with each other in the radial direction; The drive circuit board is accommodated and fixed in the pump housing, and the end cover is fixed at one end of the pump housing and covers the opening of the pump housing; The drive circuit board is electrically connected to the stator assembly of the stator-pump housing assembly, so that the stator assembly can magnetically couple and drive the rotor assembly to rotate around the shaft core in the pump cavity structure.

10. The electric water pump according to claim 9, characterized in that, In the bushing of the rotor assembly: The inner wall of the shaft hole is concave inward in the radial direction, forming a flow-through groove axially penetrating through the bushing; When the bushing of the rotor assembly is sleeved on the shaft core, liquid can flow along the flow-through groove of the bushing.

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