Electric pump

Abstract

This invention provides an electric pump that can achieve both a reduction in the number of parts and assembly man-hours, and improved heat dissipation from the control board. [Solution] The electric pump 1 comprises a support section 10, a rotor 20 including an impeller 22 and a magnet 26 and rotatably supported by the support section 10, a stator 40 including a stator core 42, a stator coil 44, and a molding material 46 covering the stator core 42 and the stator coil 44, a control board 70 for controlling the power supplied to the stator coil 44, and a casing 2 including a partition wall 50 separating the pump motor chamber 100 and the board chamber 110. The partition wall 50 of the casing 2 is formed as part of the molding material 46 by integral molding with the stator core 42, stator coil 44 and the support section 10 as insert parts, and has one or more openings 60 through which fluid flowing out from the impeller 22 can pass. The electric pump 1 further comprises a heat sink 80 provided to close the one or more openings 60 of the partition wall 50.

Description

Technical Field

[0003] , , , ,

[0004] ,

[0005] , , , , , , , , , ,

[0001] The present disclosure relates to an electric pump.

Background Art

[0002] Conventionally, an electric pump in which an impeller for boosting the pressure of a fluid and a motor unit for rotating the impeller are arranged in the same casing is known. The motor unit is controlled by a control board including electronic components typified by switching elements such as MOSFETs and IGBTs, and a printed wiring board on which the electronic components are mounted. In this type of electric pump, from the viewpoint of suppressing the temperature rise of the electronic components, the heat dissipation design of the control board is important.

[0003] For example, Patent Document 1 describes that in a water pump having an inner rotor type motor in which a rotor is arranged inside the stator in the radial direction, a heat sink (heat dissipation member) is provided so as to contact the liquid flowing inside the electric pump, and heat dissipation of the electronic components is promoted. In the water pump described in Patent Document 1, the heat sink fixed in close contact with the cylindrical portion of the housing is cooled by contact with the liquid flowing inside the housing, and heat dissipation from the electronic components is promoted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0006] In view of the above circumstances, at least some embodiments of the present invention aim to provide an electric pump that can achieve both a reduction in the number of parts and assembly man-hours and improved heat dissipation from the control board. [Means for solving the problem]

[0007] At least some embodiments of the present invention include electric pumps, Support part and A rotor including an impeller and a magnet, which is rotatably supported by the support portion, A stator comprising a stator core disposed between the magnet and the stator core with a magnetic gap between them, a stator coil wound around the stator core, and a molding material covering the stator core and the stator coil, A control board for controlling the power supplied to the stator coil, A casing that defines a pump motor chamber for housing the rotor and the stator, and a circuit board chamber for housing the control board, and includes a partition wall separating the pump motor chamber and the circuit board chamber, Equipped with, The partition wall portion of the casing is The stator core, the stator coil, and the support portion are formed as part of the molded material by integral molding using insert parts. It has one or more openings through which the fluid flowing out of the impeller can pass, The system further includes a heat sink provided to close the one or more openings in the partition wall. [Effects of the Invention]

[0008] According to at least some embodiments of the present invention, fluid passing through an opening in the partition wall of the casing separating the pump motor chamber and the substrate chamber flows toward a heat sink that closes the opening, thereby promoting heat dissipation from the control substrate via the heat sink. Furthermore, the partition wall section, which has an opening for guiding fluid to the heat sink, is formed as part of the molded material by integral molding using the stator core, stator coil, and support section as insert parts, thus reducing the number of parts and assembly man-hours. Therefore, it is possible to achieve both a reduction in the number of parts and assembly man-hours, and improved heat dissipation from the control board. [Brief explanation of the drawing]

[0009] [Figure 1A] This is an axial cross-sectional view showing a schematic configuration of an electric pump according to one embodiment. [Figure 1B] This is an axial cross-sectional view showing a schematic configuration of an electric pump according to another embodiment. [Figure 1C] This is an axial cross-sectional view showing a schematic configuration of an electric pump according to yet another embodiment. [Figure 1D] This is an axial cross-sectional view showing a schematic configuration of an electric pump according to yet another embodiment. [Figure 1E] This is an axial cross-sectional view showing a schematic configuration of an electric pump according to yet another embodiment. [Figure 2A] This is a schematic cross-sectional view showing the partition wall and the surrounding structure of the heat sink according to one embodiment. [Figure 2B] This is a partial cross-sectional perspective view corresponding to Figure 2A, showing the partition wall and the surrounding structure of the heat sink. [Figure 3A] This is a schematic cross-sectional view showing the partition wall and the surrounding structure of the heat sink according to another embodiment. [Figure 3B] This is a partial cross-sectional perspective view corresponding to Figure 3A, showing the partition wall and the surrounding structure of the heat sink. [Figure 4] This is a schematic cross-sectional view showing the partition wall and the surrounding structure of the heat sink according to yet another embodiment. [Figure 5A] This is a perspective view showing the structure of a heatsink according to one embodiment. [Figure 5B] This is a perspective view showing the structure of a heatsink according to another embodiment. [Figure 5C]It is a perspective view showing the structure of a heat sink according to another embodiment.

Mode for Carrying Out the Invention

[0010] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples.

[0011] FIG. 1A is an axial cross-sectional view showing a schematic configuration of an electric pump 1A according to an embodiment. FIG. 1B is an axial cross-sectional view showing a schematic configuration of an electric pump 1B according to another embodiment. FIG. 1C is an axial cross-sectional view showing a schematic configuration of an electric pump 1C according to yet another embodiment. FIG. 1D is an axial cross-sectional view showing a schematic configuration of an electric pump 1D according to yet another embodiment. FIG. 1E is an axial cross-sectional view showing a schematic configuration of an electric pump 1E according to yet another embodiment.

[0012] Hereinafter, when referring to the electric pumps according to some embodiments of the present invention including the electric pumps 1A to 1E, they are referred to as electric pump 1 (1A to 1E). Similarly, when referring to the electric pumps according to some embodiments including a part of the electric pumps 1A to 1E, for the purpose of clarifying the embodiments included, they may be referred to as, for example, electric pump 1 (1A, 1C), etc. The electric pump 1 (1A to 1E) may be a water pump. The electric pumps 1(1A, 1D, 1E) according to the embodiments shown in Figures 1A, 1D, and 1E are inner-rotor type electric pumps in which the rotor 20 is located radially inward of the stator 40. In contrast, the electric pump 1(1B) according to the embodiment shown in Figure 1B is an inner-rotor type electric pump in which the rotor 20 is located radially outward of the stator 40. Furthermore, the electric pump 1(1C) according to the embodiment shown in Figure 1C is an axial-gap type electric pump in which the rotor 20 and stator 40 face each other in the axial direction.

[0013] In some embodiments, as shown in Figures 1A to 1E, the electric pump 1 (1A to 1E) includes a casing 2 and a motor unit 6 and a pump unit 8 located in a pump motor chamber 100 within the casing 2. The pump motor room 100 is partially defined by the partition wall 50 of the casing 2, which will be described later.

[0014] The motor unit 6 is controlled by a control board 70 located in a substrate chamber 110 within the casing 2. The substrate chamber 110 is partially defined by the partition wall 50 of the casing 2, which will be described later.

[0015] The area of ​​the pump motor chamber 100 where the pump section 8 is located (the pump chamber) is in communication with the fluid inlet 3 and the fluid outlet 4. The fluid taken into the pump chamber from the fluid inlet 3 is pressurized as it passes through the impeller 22 of the pump section 8 and is discharged from the fluid outlet 4. In the exemplary embodiments shown in Figures 1A to 1E, the fluid is guided axially to the impeller 22 via the fluid inlet 3, and the fluid after passing through the impeller 22 is discharged from the fluid outlet 4.

[0016] In the embodiments shown in Figures 1A to 1E, the pump section 8 is a centrifugal pump that utilizes the centrifugal force generated by the rotation of the impeller 22. Specifically, the pump section 8 is a volute pump having a vortex chamber on the radially outer side of the impeller 22. The pump section 8 may be any other type of centrifugal pump as long as it includes the impeller 22, and in other embodiments, the pump section 8 is a turbine pump having guide vanes.

[0017] As described above, focusing on the function of the electric pump 1 (1A~1E), the components of the electric pump 1 (1A~1E) are mainly classified into a motor section 6, which performs the function of a motor, and a pump section 8, which performs the function of a pump. On the other hand, from the perspective of its physical components, the electric pump 1 (1A-1E) can also be classified into multiple elements. The components of the electric pump 1 (1A-1E) are described below.

[0018] In some embodiments, as shown in Figures 1A to 1E, the electric pump 1 (1A to 1E) includes the casing 2 described above, a support 10, a rotor 20 which is a rotating member, a stator 40 which is a stationary member, a control board 70 for controlling the motor 6, and a heat sink 80 for promoting heat dissipation from the control board 70.

[0019] Casing 2 includes an intermediate casing 2A and a pump casing 2B and a substrate casing 2C, which are located on either side of the intermediate casing 2A in the axial direction. The intermediate casing 2A is formed from the mold material 46 of the stator 40, which will be described later. The pump casing 2B is attached to one end of the intermediate casing 2A in the axial direction of the electric pump 1 (1A to 1E). The intermediate casing 2A and the pump casing 2B define the pump motor chamber 100 as a flow path space for housing the motor section 6 and the pump section 8. The pump casing 2B, together with the intermediate casing 2A, covers the impeller 22 of the rotor 20, which will be described later. The substrate casing 2C is attached to the other end of the intermediate casing 2A in the axial direction of the electric pump 1 (1A-1E). The intermediate casing 2A and the substrate casing 2C define a substrate chamber 110 in which the control board 70 is housed. That is, the substrate casing 2C, together with the intermediate casing 2A, covers the control board 70.

[0020] In the embodiments shown in Figures 1A to 1E, the support portion 10 is a hollow or solid stationary shaft (fixed shaft) 11 that extends along the central axis of the impeller 22. The stationary shaft 11, as the support portion 10, extends axially within the pump motor chamber 100. When the support portion 10 is a stationary shaft 11, the rotor 20 is rotatably supported on the support portion 10 (stationary shaft 11) via a bearing 12. In other embodiments not shown, the support portion 10 is a bearing that rotatably supports the rotation axis of the rotor 20, which extends along the central axis of the impeller 22, on the casing 2 or stator 40.

[0021] In the exemplary embodiments shown in Figures 1A, 1D, and 1E, the support portion 10 is a solid stationary shaft 11. In contrast, in the exemplary embodiments shown in Figures 1B and 1C, the support portion 10 is a hollow stationary shaft 11 and has an internal space 13 that extends in the axial direction.

[0022] A rotor 20, which is rotatably supported by the support 10, is provided on the radially outer side of the support 10. The rotor 20 is located inside the pump motor chamber 100.

[0023] The rotor 20 includes an impeller 22 and a magnet 26, as shown in Figures 1A to 1E. The impeller 22 is positioned facing the fluid inlet 3 of the casing 2 in the axial direction. The magnet 26 is located on the opposite side of the impeller 22 from the fluid inlet 3 in the axial direction (on the back side of the impeller 22).

[0024] The impeller 22 of the rotor 20 includes a plurality of blades 23 arranged in the circumferential direction. An intake port 22A is formed between the leading edges of adjacent blades 23, and an outlet port 22B is formed between the trailing edges of adjacent blades 23. The intake port 22A of the impeller 22 is in communication with the fluid inlet 3, and the fluid flowing in from the fluid inlet 3 is given kinetic energy by the rotating impeller 22. The outlet port 22B of the impeller 22 is in communication with the fluid outlet 4, and the fluid after passing through the impeller 22 flows radially outward through the outlet port 22B and is discharged from the fluid outlet 4. The pump motor chamber 100 is filled with fluid. That is, all gaps within the pump motor chamber 100, including the air gap 48 between the rotor 20 and the stator 40 (described later) and the bearing gap of the bearing 12, are in communication with the discharge port 22B of the impeller 22, and some of the fluid after passing through the impeller 22 may flow into these gaps. Some of the fluid after passing through the impeller 22 is returned to the suction port 22A of the impeller 22 via the gaps within the pump motor chamber 100, including the air gap 48 and the bearing gap of the bearing 12.

[0025] The impeller 22 may have a shroud 24. In the exemplary embodiments shown in Figures 1A to 1E, the impeller 22 is a closed impeller and includes a shroud 24 covering the blades 23. In another embodiment, the impeller 22 is an open impeller without a shroud covering the blades 23.

[0026] The magnet 26 is a permanent magnet positioned opposite the stator 40. In the embodiments shown in Figures 1A to 1E, the electric pump 1 (1A to 1E) is an SPM motor in which the magnet 26 (permanent magnet) is exposed on the surface of the rotor 20, and the magnet 26 is provided so as to be exposed on the surface of the rotor 20 that faces the stator 40. Note that there may be one magnet 26 per electric pump 1 (1A to 1E), or multiple magnets 26 may be used. The shape of the magnet 26 can be arbitrarily selected to match the shape of the stator 40, and may be cylindrical, arc-shaped, disc-shaped, or rod-shaped, for example.

[0027] In some embodiments, as shown in Figures 1A to 1E, the rotor 20 further includes, in addition to the impeller 22 and magnet 26 configured above, a magnet holding portion 21 formed integrally with at least the magnet 26. In the embodiments shown in Figures 1A to 1D, the magnet holder 21 is located on the opposite side of the fluid inlet 3 from the impeller 22 in the axial direction, and holds the magnet 26 so as to face the stator 40.

[0028] The magnet holder portion 21 may be formed from a resin material. In this case, the rotor 20 can be formed by insert molding. That is, by insert molding with the magnet 26 as an insert component, a rotor 20 can be obtained in which at least the magnet 26 and the magnet holder portion 21 are integrally formed. In other embodiments, the magnet holder 21 is formed by a rotor core (not shown) made of a laminate of electromagnetic steel sheets.

[0029] As shown in Figures 1A to 1E, the stator 40 is a stationary member provided opposite the rotor 20 of the above configuration, and includes a stator core 42, a stator coil 44, and a molding material 46.

[0030] The stator core 42 forms a magnetic path through which the magnetic flux generated by energizing the stator coil 44 flows. The stator core 42 is positioned with a magnetic gap G between it and the magnet 26 of the rotor 20. The magnetic gap G is formed over the region where the stator core 42 and the magnet 26 face each other. The stator 40 faces the rotor 20 non-contactingly, separated by an air gap 48 within the range of the magnetic gap G. In the embodiments shown in Figures 1A, 1B, 1D, and 1E, the magnetic gap G is a radial magnetic gap that extends in an annular shape along the axial direction of the rotor 20. In contrast, in the embodiment shown in Figure 1C, the magnetic gap G is an axial magnetic gap that extends in a disk shape along the radial direction of the rotor.

[0031] In the inner rotor type electric pump 1 (1A, 1D, 1E) shown in Figures 1A, 1D, and 1E, the magnet 26 is positioned radially inward of the stator core 42 so as to form a radial magnetic gap G between it and the stator core 42. In the outer rotor type electric pump 1(1B) shown in Figure 1B, the magnet 26 is positioned radially outward of the stator core 42 so as to form a radial magnetic gap G between it and the stator core 42. In the axial gap type electric pump 1(1C) shown in Figure 1C, the magnet 26 is located on the back side of the impeller 22 so as to form an axial magnetic gap G between the stator core and 42.

[0032] The stator coil 44 is wound around the stator core 42. The stator coil 44 may be wound around the teeth of the stator core 42 so as to be housed in slots provided in the stator core 42.

[0033] The stator core 42 and stator coil 44 are covered by a resin molding material 46. That is, the stator core 42 and stator coil 44 are embedded in the molding material 46. Thus, a stator 40 in which the stator core 42 and stator coil 44 are covered by a resin mold material 46 can be obtained by insert molding. Specifically, the stator core 42 and stator coil 44 are set as insert parts in a mold, and resin is injected into the mold to obtain a stator 40 in which the stator core 42 and stator coil 44 are embedded in the mold material 46.

[0034] The power supplied to the stator coil 44 of the stator 40 in the above configuration is controlled by a control board 70 located in the substrate chamber 110. The control board 70 includes a printed circuit board 72 and electronic components 74 mounted on the printed circuit board 72. The electronic components 74 include, for example, switching elements such as MOSFETs and IGBTs, and passive components such as capacitors, resistors, and coils. One or more electronic components 74 are mounted on the surface of the printed circuit board 72 facing the heat sink 80. Alternatively, one or more electronic components 74 may be mounted on the surface of the printed circuit board 72 opposite to the heat sink 80.

[0035] In some embodiments, as shown in Figures 1A to 1E, the internal space of the casing 2 is divided by a partition wall 50 of the casing 2 into a substrate chamber 110 housing the control board 70 and a pump motor chamber 100 housing the rotor 20 and stator 40. The partition wall 50 of the casing 2 separates the pump motor chamber 100, which is filled with fluid, from the substrate chamber 110, which does not contain fluid. The partition wall 50 of the casing 2 partially defines the pump motor chamber 100 and the substrate chamber 110, respectively. In the embodiments shown in Figures 1A to 1E, the partition wall 50 of the casing 2 is located in the axial direction between the pump motor chamber 100 and the substrate chamber 110. The partition wall 50 has a first wall surface 52 on the pump motor chamber 100 side and a second wall surface 54 on the substrate chamber 110 side. The first wall surface 52 of the partition wall 50 forms at least partially the bottom surface of the pump motor chamber 100. The second wall surface 54 of the partition wall 50 forms at least partially the ceiling surface of the substrate chamber 110.

[0036] The partition wall 50 of the casing 2 is integrally provided with the support portion 10 and the stator 40. Specifically, the partition wall 50 is formed as part of a resin molded material 46 by integral molding with the stator core 42, stator coil 44, and support portion 10 as insert parts. The partition wall 50, which is integrally provided with the support portion 10 and the stator 40, can be obtained by injecting resin into the mold while it is set in the mold as an insert part together with the stator core 42 and the stator coil 44. The partition wall 50 may also be part of the mold material 46 that constitutes the intermediate casing 2A. In some embodiments, as shown in Figures 1A to 1E, the partition wall 50 is integrally provided with the stationary shaft 11 and stator 40, which serve as the support portion 10. In other embodiments, the partition wall 50 is integrally provided with the bearing and stator 40, which serve as the support portion 10.

[0037] In the embodiments shown in Figures 1A to 1E, the end 14 of the stationary shaft 11, which serves as the support portion 10, opposite to the impeller 22 in the axial direction, is embedded in a part of the molded material 46 that constitutes the partition wall portion 50 (the portion of the molded material 46 that constitutes the partition wall portion 50). In another embodiment, the end 14 of the bearing, which serves as the support portion 10, opposite the impeller 22 in the axial direction is embedded in a part of the molded material 46 that constitutes the partition wall portion 50 (the portion of the molded material 46 that constitutes the partition wall portion 50).

[0038] In some embodiments, the partition wall 50 has one or more openings 60 through which the fluid flowing out of the impeller 22 can pass, as shown in Figures 1A to 1E. The partition wall 50 may have multiple openings 60. Each of the openings 60 is connected to the discharge port 22B of the impeller 22, and the fluid flowing out from the impeller 22 can flow through the pump motor chamber 100 and pass through the openings 60. The shape of each opening 60 is not particularly limited and may be any shape. Each opening 60 may have a circular shape, or a non-circular shape such as an ellipse, track shape, sector shape, rectangle, or square.

[0039] In the embodiments shown in Figures 1A, 1D, and 1E, the opening 60 of the partition wall 50 is located downstream of the gap 48 between the rotor 20 and the stator 40 with respect to the direction of fluid flow within the pump motor chamber 100. In this case, the fluid flowing out from the impeller 22 passes through the gap 48 between the rotor 20 and the stator 40, and then passes through the opening 60 of the partition wall 50. In contrast, in the embodiments shown in Figures 1B and 1C, with respect to the direction of fluid flow within the pump motor chamber 100, the opening 60 of the partition wall 50 is provided in parallel with the gap 48 between the rotor 20 and the stator 40. In this case, the fluid flowing out from the impeller 22 is divided upstream of the gap 48 between the rotor 20 and the stator 40 and the opening 60 of the partition wall 50, and a portion of it passes through the opening 60 of the partition wall 50.

[0040] Each opening 60 is provided through the partition wall 50 and has a first opening end 61 that opens to the first wall surface 52 on the pump motor room 100 side of the partition wall 50, and a second opening end 62 which is the opening end on the opposite side from the first opening end 61.

[0041] In the exemplary embodiments shown in Figures 1A to 1E, each opening 60 of the partition wall 50 is provided around the end 14 of the stationary shaft 11, which serves as the support 10, opposite to the impeller 22. In this case, the first opening end 61 of each opening 60 is located in the axial direction within the extending range of the end 14 of the stationary shaft 11. In other words, the end 14 of the stationary shaft 11 extends in the axial direction beyond the first opening end 61 of each opening 60 to the side opposite the impeller 22. As illustrated in Figures 1A to 1E, the second opening end 62 of each opening 60 may be located within the extension range of the end 14 of the stationary shaft 11 in the axial direction. In other words, the end 14 of the stationary shaft 11 may extend beyond the second opening end 62 of each opening 60 to the opposite side from the impeller 22 in the axial direction.

[0042] As shown in Figures 1A to 1E, one or more openings 60 in the partition wall 50 are blocked by heat sinks 80 to promote heat dissipation from the control board 70. The heat sinks 80 prevent fluid that has passed through the openings 60 from entering the substrate chamber 110.

[0043] In the embodiments shown in Figures 1A to 1E, the heat sink 80 is positioned facing the partition wall 50 in the axial direction such that a chamber 64 is formed between the heat sink 80 and the partition wall 50. The chamber 64 communicates with one or more openings 60 in the partition wall 50 and is a space through which fluid can flow. The heat sink 80 is placed inside the substrate chamber 110 and, together with the partition wall 50, defines the chamber 64. In this case, the fluid that passes through the opening 60 flows into the chamber 64 to cool the heat sink 80. The fluid can enter and exit the chamber 64 through the opening 60, and the fluid in the chamber 64 is discharged through one of the openings 60. In this way, the fluid in the chamber 64 is replaced by the fluid entering and exiting through the opening 60, allowing for efficient cooling of the heat sink 80. Furthermore, if the partition wall 50 has multiple openings 60, the chamber 64 may be a single shared chamber communicating with all the openings 60, as shown in Figures 1A to 1E. Alternatively, multiple independent chambers 64 may each communicate with at least one corresponding opening 60.

[0044] In the exemplary embodiments shown in Figures 1B and 1C, the chamber 64 communicates with the internal space 13 of the hollow support portion 10 (stationary shaft 11) via a communication hole 51 provided in the partition wall portion 50. The fluid that passes through the opening 60 of the partition wall 50 flows through the chamber 64 and is then returned to the intake port 22A of the impeller 22 via the communication hole 51 and the internal space 13 of the support portion 10. In this case, it is possible to effectively replace the fluid in the chamber 64, thereby enhancing the cooling effect of the heat sink 80 by the fluid.

[0045] The heatsink 80 is made of a material with a higher thermal conductivity than the molding material 46. The materials constituting the heat sink 80 are not particularly limited and include, for example, metal materials such as copper, aluminum, and alloys containing them; resin compositions such as PPS resin, PA6 resin, and PEEK resin; and composite materials in which carbon fibers or graphite powder are added to a matrix resin. The resin compositions such as PPS resin, PA6 resin, and PEEK resin may contain fillers.

[0046] In the embodiments shown in Figures 1A to 1E, the heat sink 80 is a plate component whose plate thickness t is sufficiently smaller than its dimensions in other directions. Specifically, the dimensions of the heat sink 80 along the axial direction of the electric pump 1 (1A to 1E) (plate thickness t) are less than 1 / 3 of the dimensions of the heat sink 80 along the radial direction of the electric pump 1 (1A to 1E) (plate width), for example, 1 / 10 or less. In another embodiment, the heat sink 80 has dimensions (plate thickness t) along the axial direction of the electric pump 1 (1A to 1E) that are at least 1 / 3 times the dimensions (plate width) of the heat sink 80 along the radial direction of the electric pump 1 (1A to 1E).

[0047] The shape of the heatsink 80 is not particularly limited and may be any shape, including cup shape, hat shape, flat plate shape, etc. In the embodiments shown in Figures 1A to 1C and Figure 1E, the heat sink 80 has a hat shape with a recess 82. In this case, the partition wall portion 50 of the casing 2 has an annular projection 56 that protrudes toward the substrate chamber 110 so as to surround one or more openings 60, and the recess 82 of the heat sink 80 fits into the annular projection 56 of the partition wall portion 50. In contrast, in the embodiment shown in Figure 1D, the heat sink 80 has a flat plate shape.

[0048] Furthermore, in the embodiment shown in Figure 1E, the heat sink 80 has a plurality of protrusions 84 formed on the surface facing the partition wall 50, from the viewpoint of increasing the heat transfer area. In this case, each protrusion 84 projects toward the partition wall 50 so as to enter the chamber 64 between the heat sink 80 and the partition wall 50. In other embodiments, as shown in Figures 1A to 1D, the surface of the heat sink 80 facing the partition wall 50 is a flat surface. In this case, the surface of the heat sink 80 facing the partition wall 50 (the flat surface) defines the chamber 64 between the heat sink 80 and the partition wall 50.

[0049] The heat sink 80 may be provided in direct contact with the electronic components 74 of the control board 70, from the viewpoint of promoting heat dissipation from the electronic components 74. Alternatively, as shown in Figures 1A to 1E, the electric pump 1 (1A to 1E) may further include a heat dissipation material 76 provided between the electronic component 74 and the heat sink 80. For example, thermal grease can be used as the heat dissipation material 76. When the heat dissipation material 76 is used, the heat sink 80 is at least partially non-contact with the electronic component 74, and the gap between the heat sink 80 and the electronic component 74 may be filled with the heat dissipation material 76.

[0050] In some embodiments, as shown in Figures 1A to 1E, the electric pump 1 (1A to 1E) includes a sealing member 90 provided between the heat sink 80 and the partition wall 50. The sealing member 90 is provided in an annular shape so as to surround one or more openings 60 of the partition wall 50. The heat sink 80 is fastened to the partition wall 50 by screws 81 on the radially outer side of the sealing member 90. In other embodiments, the heat sink 80 is fixed to the partition wall 50 by welding on the radially outer side of the sealing member 90. In the embodiments shown in Figures 1A to 1E, the sealing member 90 is attached to a circumferentially continuous annular groove 91 provided on the second wall surface 54 of the partition wall 50 on the substrate chamber 110 side. In other embodiments not shown, the sealing member 90 is attached to an annular groove provided on the heat sink 80. The sealing member 90 is not particularly limited in its configuration as long as it can seal the gap between the heat sink 80 and the partition wall 50, and any sealing member with any configuration can be used. The sealing member 90 may be, for example, a sealing ring having any cross-sectional shape, such as an O-ring or an X-ring. In the exemplary embodiments shown in Figures 1A to 1E, the sealing member 90 is an O-ring.

[0051] Next, with reference to Figures 2A to 4, the specific configuration of the partition wall 50 and the heat sink 80 will be described. Figure 2A is a schematic cross-sectional view showing the peripheral structure of the partition wall 50 and heat sink 80 according to one embodiment. Figure 2B is a partial cross-sectional perspective view corresponding to Figure 2A, showing the peripheral structure of the partition wall 50 and heat sink 80. Figure 3A is a schematic cross-sectional view showing the peripheral structure of the partition wall 50 and heat sink 80 according to another embodiment. Figure 3B is a partial cross-sectional perspective view corresponding to Figure 3A, showing the peripheral structure of the partition wall 50 and heat sink 80. Figure 4 is a schematic cross-sectional view showing the peripheral structure of the partition wall 50 and heat sink 80 according to yet another embodiment. Furthermore, for any of the electric pumps 1 (1A to 1E) described above, the configuration of the partition wall 50 and heat sink 80 shown in Figures 1A to 1E can be replaced with the configuration of the partition wall 50 and heat sink 80 described below, referring to Figures 2A to 4.

[0052] In some embodiments, as shown in Figures 2A to 4, the partition wall 50 has a plurality of openings 60 formed to be aligned circumferentially. The plurality of openings 60 are formed in the partition wall 50 to be aligned circumferentially around the end 14 of the support 10 opposite to the impeller 22 in the axial direction. Each opening 60 communicates with a chamber 64 formed between the partition wall 50 and the heat sink 80. In the embodiments shown in Figures 2A and 2B, six openings 60 are formed in the partition wall 50 at equal intervals in the circumferential direction. In the embodiments shown in Figures 3A and 3B, six openings 60A are formed in the partition wall 50 at equal intervals in the circumferential direction, and six openings 60B are formed at equal intervals in the circumferential direction.

[0053] In some embodiments, as shown in Figures 3A to 4, the partition wall 50 includes a plurality of first openings 60A arranged in the circumferential direction and a plurality of second openings 60B arranged in the circumferential direction radially inward from the plurality of first openings 60A. The plurality of first openings 60A and the plurality of second openings 60B each communicate with a chamber 64 formed between the heat sink 80 and the partition wall 50. In the exemplary embodiments shown in Figures 3A to 4, the radially outer boundary of the first opening 60A is defined by a tapered surface 66A that curves radially inward as it approaches the chamber 64 in the axial direction of the electric pump 1. Therefore, when the fluid that has passed through the impeller 22 passes through the first opening 60A, it flows into the chamber 64 while being deflected radially inward by the tapered surface 66A, and is effectively guided to the second opening 60B, which is located radially inward of the first opening 60A. On the other hand, the radially inner boundary of the second opening 60B is defined by a tapered surface 66B that curves radially inward as it approaches the chamber 64 in the axial direction of the electric pump 1. Therefore, the fluid flowing radially inward within the chamber 64 is guided axially away from the chamber 64 by the tapered surface 66B, thereby promoting the discharge of fluid from the chamber 64 through the second opening 60B.

[0054] In some embodiments, as shown in Figures 2A to 4, the partition wall 50 includes a substantially cylindrical portion 45 into which the end 14 of the support portion 10 opposite to the impeller 22 is embedded, and a plurality of openings 60 are arranged circumferentially surrounding the cylindrical portion 45. The partition wall 50 has a tapered surface 47 connecting the first wall surface 52 on the pump motor chamber 100 side and the outer circumferential surface of the cylindrical portion 45. The tapered surface 47 is radially inward as it moves away from the chamber 64 in the axial direction. Fluid that does not pass through the opening 60 flows radially inward along the first wall surface 52 on the pump motor chamber 100 side of the partition wall 50, then is redirected axially by the tapered surface 47, and is returned to the impeller 22 side, for example, by passing through the bearing gap of the bearing 12. In the embodiments shown in Figures 2A and 2B, the cylindrical portion 45 protrudes axially towards the heat sink 80 beyond the second opening end 62 of each opening 60 and enters the chamber 64. In the embodiments shown in Figures 3A to 4, the cylindrical portion 45 extends axially to the same axial position as the second opening end 62 of each opening 60.

[0055] In some embodiments, as shown in Figure 4, the partition wall 50 has a welded portion 55 that is welded to the heat sink 80. The welded portion 55 is formed in an annular shape so as to surround a plurality of openings 60. The welded portion 55 only needs to be liquid-tight enough to prevent fluid from entering the substrate chamber 110, and the specific method for forming the welded portion 55 is not particularly limited. The welded portion 55 can be formed by, for example, hot plate welding, vibration welding, ultrasonic welding, infrared welding, laser welding, spin welding, etc.

[0056] In the exemplary embodiments shown in Figures 2A and 2B, the annular projection 56 of the partition wall 50 is fitted into the recess 82 of the hat-shaped heat sink 80, and the heat sink 80 is fastened to the partition wall 50 by screws 81. An annular groove 91, which is continuous in the circumferential direction, is provided at the protruding end of the annular projection 56, and an annular sealing member 90 is placed in the annular groove 91. The annular sealing member 90 surrounds the multiple openings 60 of the partition wall 50. The fastening position of the heat sink 80 to the partition wall 50 by screws 81 is radially outward of the annular sealing member 90.

[0057] In the exemplary embodiments shown in Figures 3A and 3B, an annular sealing member 90 for sealing the gap between the flat heat sink 80 and the partition wall 50 is positioned in an annular groove 91 provided on the second wall surface 54 of the partition wall 50 on the substrate chamber 110 side. The flat heat sink 80 is fastened to the partition wall 50 by screws 81. The annular sealing member 90 surrounds a plurality of openings 60 (60A, 60B) in the partition wall 50. The fastening position of the heat sink 80 to the partition wall 50 by screws 81 is radially outward of the annular sealing member 90.

[0058] In the exemplary embodiment shown in Figure 4, a substantially flat heat sink 80 is welded to the partition wall 50 at an annular welded portion 55 provided on the partition wall 50. The annular welded portion 55 surrounds a plurality of openings 60 (60A, 60B).

[0059] Next, with reference to Figures 5A to 5C, the specific configuration of the protrusion 84 of the heatsink 80 will be described. Figure 5A is a perspective view showing the structure of a heat sink according to one embodiment. Figure 5B is a perspective view showing the structure of a heat sink according to another embodiment. Figure 5C is a perspective view showing the structure of a heat sink according to yet another embodiment. Furthermore, for any of the electric pumps 1 (1A to 1E) described above, the configuration of the heat sink 80 shown in Figures 1A to 1E can be replaced with the configuration of the heat sink 80 described below, referring to Figures 5A to 5C. In the exemplary embodiments shown in Figures 5A to 5C, the heat sink 80 (80A to 80C) has a substantially disc shape, but in other embodiments, the heat sink 80 may be a polygon such as a square or rectangle, or it may be elliptical or track-shaped.

[0060] In the embodiments shown in Figures 5A to 5C, the heat sink 80 (80A to 80C) has a plurality of protrusions 84 (84A to 84C) formed on the surface facing the partition wall 50. The method for forming the protrusions 84 is not particularly limited, and the protrusions 84 may be formed, for example, by embossing or by die casting. The protruding height of the protrusion 84 is not particularly limited, but when the protrusion 84 is formed by embossing, the ratio of the protruding height of the protrusion 84 to the plate thickness t may be 0.1 or more and 0.5 or less. Also, when the protrusion 84 is formed by die casting, the ratio of the protruding height of the protrusion 84 to the plate thickness t may be 0.2 or more and 1 or less.

[0061] In the exemplary embodiment shown in Figure 5A, the heat sink 80A includes a plurality of circumferentially aligned protrusions 84A. Each protrusion 84A belongs to one of the rows of protrusions 85 (85A to 85C) located at different radial positions. The number of protrusions 84A belonging to row 85A, located on the outermost circumference (12), is greater than the number of protrusions 84A belonging to row 85B, located on the inner circumference side of row 85A (8). The arrangement pitch (angle) of the protrusions 84A in the circumferential direction differs between row 85A and row 85B. The innermost row of protrusions 85C has one protrusion 84A.

[0062] In the exemplary embodiment shown in Figure 5B, the heat sink 80B includes a plurality of circumferentially continuous protrusions 84B. Each of the protrusions 84B is located at a different radial position from the others. The outermost protrusion 84B and the protrusion 84B on its inner side are continuous annular protrusions in the circumferential direction. The innermost protrusion 84B is a continuous circular protrusion in the circumferential direction.

[0063] In the exemplary embodiment shown in Figure 5C, the heat sink 80C includes a plurality of vanes 84C as a protrusion 84, which are curved radially inward. The plurality of vanes 84C are curved in the same direction. Each vane 84C has a concave curved surface 86A and a convex curved surface 86B. The curvature direction of each vane 84C may be set according to the rotation direction of the rotor 20 in the electric pump 1. The fluid that has passed through the opening 60 of the partition wall 50 flows into the chamber 64 while maintaining a swirling component along the rotation direction of the rotor 20, and may flow in the direction of the arrow in Figure 5C. At this time, the fluid with the swirling component flows along the concave curved surface 86A of the vane 84C.

[0064] The characteristic configurations of the electric pump 1 (1A to 1E) according to some of the embodiments described above can be summarized as follows.

[0065] [1] At least some embodiments of the present invention include electric pumps (1; 1A to 1E), Support part (10) and A rotor (20) is rotatably supported on a support (10), and includes an impeller (22) and a magnet (26). A stator (40) includes a stator core (42) positioned with a magnetic gap (G) between it and a magnet (26), a stator coil (44) wound around the stator core (42), and a molding material (46) covering the stator core (42) and the stator coil (44), A control board (70) for controlling the power supplied to the stator coil (44), The casing (2) partially defines a pump motor chamber (100) housing a rotor (20) and a stator (40), and a circuit board chamber (110) housing a control board (70), and includes a partition wall (50) separating the pump motor chamber (100) and the circuit board chamber (110), Equipped with, The partition wall portion (50) of the casing (2) is The stator core (42), stator coil (44), and support part (10) are formed as part of the molded material (46) by integral molding using insert parts. The impeller (22) has one or more openings (60) through which the fluid flowing out can pass, The system further includes a heat sink (80) provided to close the one or more openings (60) in the partition wall (50).

[0066] According to the configuration described in [1] above, the fluid that passes through the opening (60) in the partition wall (50) of the casing (2) that separates the pump motor room (100) and the circuit board room (110) flows toward the heat sink (80) that closes the opening (60), thereby promoting heat dissipation from the control board (70) via the heat sink (80). Furthermore, the partition wall portion (50) having an opening (60) for guiding fluid to the heat sink (80) is formed as part of the molded material (46) by integral molding with the stator core (42), stator coil (44), and support portion (10) as insert parts, thus reducing the number of parts and assembly man-hours. Therefore, it is possible to achieve both a reduction in the number of parts and assembly man-hours, and improved heat dissipation from the control board (70).

[0067] [2] In some embodiments, in the configuration of [1] above, The heat sink (80) is positioned in the substrate chamber (100) facing the partition wall (50) such that a chamber (64) communicating with one or more openings (60) is formed between the heat sink (80) and the partition wall (50).

[0068] According to the configuration described in [2] above, the fluid that flows into the chamber (64) through the opening (60) provided in the partition wall (50) cools the heat sink (80) facing the chamber (64), thereby more effectively promoting heat dissipation from the control board (70).

[0069] [3] In some embodiments, in the configuration of [1] or [2] above, The heat sink (80) is a plate component with higher thermal conductivity than the molded material (46).

[0070] According to the configuration described in [3] above, the heat sink (80) has a higher thermal conductivity than the molding material (46), which allows for more effective heat dissipation from the control board (70). Furthermore, as described in [1] above, the support portion (10) is integrally formed with the molded material (46) that constitutes the partition wall portion (50). For this reason, the heat sink (80) does not need to have the function of supporting the support portion (10), and a plate component form that prioritizes heat dissipation can be adopted. As the heat sink (80) is a plate component, its dimensions (plate thickness) are small in the heat dissipation path from the control board (70) to the fluid, so it can more effectively promote heat dissipation from the control board (70).

[0071] [4] In some embodiments, in any of the configurations described in [1] to [3] above, The electric pump (1; 1A~1E) is equipped with a sealing member (90) provided in an annular shape to surround one or more openings (60) between the heat sink (80) and the partition wall (50).

[0072] According to the configuration described in [4] above, the sealing member (90) can prevent fluid that has passed through one or more openings (60) from entering the substrate chamber (110), thereby improving the reliability of the electric pumps (1; 1A to 1E).

[0073] [5] In some embodiments, in any of the configurations described in [1] to [3] above, The partition wall (50) has a welded portion (55) that is welded to the heat sink (80), The welded portion (55) is formed in an annular shape so as to surround one or more openings (60).

[0074] According to the configuration described in [5] above, by welding the partition wall (50) and the heat sink (80) at the annular welded portion (55), it is possible to prevent the fluid that has passed through one or more openings (60) from entering the substrate chamber (110), thereby improving the reliability of the electric pump (1).

[0075] [6] In some embodiments, in any of the configurations [1] to [5] above, The partition wall (50) has an annular projection (56) that protrudes toward the substrate chamber (110) so as to surround one or more openings (60), The heat sink (80) has a recess (82) that fits into the annular protrusion (56).

[0076] According to the configuration described in [6] above, by fitting the recess (82) of the heat sink (80) into the annular protrusion (56) of the partition wall (50), the heat sink (80) can be positioned closer to the control board (70), thereby more effectively promoting heat dissipation from the control board (70).

[0077] [7] In some embodiments, in the configuration of [1] or [2] above, One or more openings (60) include a plurality of openings (60) formed in the partition wall portion (50) so as to be aligned in the circumferential direction.

[0078] According to the configuration described in [7] above, the heat sink (80) can be cooled by the fluid taken in through the multiple openings (60) arranged in the circumferential direction, thereby more effectively promoting heat dissipation from the control board (70).

[0079] [8] In some embodiments, in the configuration of [7] above, The end (14) of the support portion (10) opposite to the impeller (22) in the axial direction is embedded in a part of the molded material (46) that constitutes the bulkhead portion (50). Multiple openings (60) are formed in a part of the mold material (46) so as to be arranged circumferentially around the end (14) of the support portion (10).

[0080] According to the configuration described in [8] above, by arranging a plurality of openings (60) in a circumferential direction around the end (14) of the support portion (10) embedded in the partition wall portion (50; part of the mold material 46), fluid can be guided to the heat sink (80) while ensuring the embedded length of the end (14) of the support portion (10) in the partition wall portion (50). Therefore, it is possible to promote heat dissipation from the control board (70) while suppressing an increase in the axial dimension of the electric pump (1; 1A~1E).

[0081] [9] In some embodiments, in any of the configurations [1] to [8] above, One or more openings (60) Multiple first openings (60A) are formed in the partition wall (50) so as to be aligned in the circumferential direction, Multiple second openings (60B) are formed in the partition wall portion (50) so as to be aligned circumferentially radially inward from the multiple first openings (60A), Includes, Multiple first openings (60A) and multiple second openings (60B) communicate with a chamber (64) formed between the heat sink (80) and the partition wall (50).

[0082] According to the configuration described in [9] above, the partition wall (50) has a plurality of first openings (60A) and a plurality of second openings (60B) formed at different radial positions from each other, which facilitates the exchange of fluid into and out of the chamber (64) between the heat sink (80) and the partition wall (50), thereby enhancing the heat dissipation effect of the heat sink (80).

[0083]

[10] In some embodiments, in any of the configurations [1] to [9] above, The control board (70) is Printed circuit board (72), Electronic components (74) mounted on a printed circuit board (72), Includes, The electric pump (1; 1A~1E) further includes a heat dissipation material (76) placed between the electronic component (74) and the heat sink (80).

[0084] According to the configuration described in

[10] above, by providing a heat dissipation material (76) between the heat sink (80) and the electronic component (74), heat dissipation from the electronic component (74) can be promoted.

[0085]

[11] In some embodiments, in any of the configurations [1] to

[10] above, The heat sink (80) has a plurality of protrusions (84; 84A~84C) formed on the surface facing the partition wall (50).

[0086] According to the configuration described in

[11] above, by providing a plurality of protrusions (84; 84A~84C) on the surface of the heat sink (80) facing the partition wall (50), it is possible to enjoy the heat dissipation promotion effect resulting from an increase in the heat transfer area of ​​the heat sink (80).

[0087]

[12] In some embodiments, in any of the configurations [1] to

[11] above, Casing (2) is An intermediate casing (2A) formed by a mold material (46), A pump casing (2B) is attached to one end of the intermediate casing (2A) in the axial direction and covers the impeller (22) together with the intermediate casing (2A), A substrate casing (2C) is attached to the other end of the intermediate casing (2A) in the axial direction and covers the control board (70) together with the intermediate casing (2A), Includes.

[0088] According to the configuration described in

[12] above, the intermediate casing (2A), which is a component of the casing (2), can be formed by a molded material (46) that constitutes a partition wall (50) having an opening (60) for guiding fluid to the heat sink (80), thereby reducing the number of parts.

[0089]

[13] In some embodiments, in any of the configurations described in [1] to

[12] above, The magnet (26) is positioned radially inward of the stator core (42) so as to form a radial magnetic gap (G) between it and the stator core (42).

[0090] According to the configuration described in

[13] above, in an inner rotor type electric pump (1; 1A, 1D, 1E) in which the rotor (20) including the magnet (26) is located radially inward of the stator (40), as described in [1] above, it is possible to promote heat dissipation from the control board (70) and reduce the number of parts and assembly man-hours.

[0091]

[14] In some embodiments, in any of the configurations [1] to

[12] above, The magnet (26) is positioned radially outward of the stator core (42) so as to form a radial magnetic gap (G) between it and the stator core (42).

[0092] According to the configuration described in

[14] above, in an outer rotor type electric pump (1;1B) in which the rotor (20) including the magnet (26) is located radially outside the stator (40), as described in [1] above, it is possible to promote heat dissipation from the control board (70) and reduce the number of parts and assembly man-hours.

[0093]

[15] In some embodiments, in any of the configurations [1] to

[12] above, The magnet (26) is positioned on the back side of the impeller (22) so as to form an axial magnetic gap (G) between it and the stator core (42).

[0094] According to the configuration described in

[15] above, in an axial gap type electric pump (1;1C) in which a rotor (20) including a magnet (26) is axially opposed to a stator (40), as described in [1] above, it is possible to promote heat dissipation from the control board (70) and reduce the number of parts and assembly man-hours. [Explanation of Symbols]

[0095] 1 (1A~1E): Electric pump 2: Casing 2A: Intermediate casing 2B: Pump casing 2C: PCB casing 10: Support part 14: End 20: Rotor 22: Impeller 26: Magnet 40: Status 42: Stator Core 44: Stator coil 46: Mold material 50: Partition part 55: Welded part 56: Ring-shaped protrusion 60:Aperture 60A: First opening 60B: 2nd opening 64: Chamber 70: Control board 70: Heat dissipation material 72: Printed circuit board 74: Electronic components 76: Heat dissipation material 80 (80A~80C): Heatsink 82: Recess 84(84A,84B): Convex part 90: Sealing material 100: Pump motor room 110: Circuit board room G: Magnetic gap

Claims

1. Support part and A rotor including an impeller and a magnet, which is rotatably supported by the support portion, A stator comprising a stator core disposed between the magnet and the stator core with a magnetic gap between them, a stator coil wound around the stator core, and a molding material covering the stator core and the stator coil, A control board for controlling the power supplied to the stator coil, A casing that partially defines a pump motor chamber housing the rotor and the stator, and a circuit board chamber housing the control board, and includes a partition wall separating the pump motor chamber and the circuit board chamber, Equipped with, The partition wall portion of the casing is The stator core, the stator coil, and the support portion are formed as part of the molded material by integral molding using insert parts. It has one or more openings through which the fluid flowing out of the impeller can pass, The partition wall portion further comprises a heat sink provided to close the one or more openings. Electric pump.

2. The heat sink is positioned in the substrate chamber facing the partition wall such that a chamber communicating with the one or more openings is formed between the heat sink and the partition wall. The electric pump according to claim 1.

3. The electric pump according to claim 1 or 2, wherein the heat sink is a plate component with a higher thermal conductivity than the molded material.

4. The heat sink and the partition wall are provided with a sealing member that is provided in an annular shape to surround the one or more openings. The electric pump according to claim 1 or 2.

5. The partition wall portion has a welded portion welded to the heat sink, The welded portion is formed in an annular shape so as to surround the one or more openings. The electric pump according to claim 1 or 2.

6. The partition wall portion has an annular projection that protrudes toward the substrate chamber so as to surround the one or more openings. The heat sink has a recess that fits into the annular protrusion. The electric pump according to claim 1 or 2.

7. The one or more openings mentioned above include a plurality of openings formed in the partition wall so as to be aligned in the circumferential direction. The electric pump according to claim 1 or 2.

8. The end of the support portion opposite to the impeller in the axial direction is embedded in the part of the mold material that constitutes the partition wall portion. The plurality of openings are formed in a portion of the mold material so as to be arranged circumferentially around the end of the support portion. The electric pump according to claim 7.

9. The one or more openings mentioned above are A plurality of first openings formed in the partition wall so as to be aligned in the circumferential direction, A plurality of second openings are formed in the partition wall portion so as to be aligned in the circumferential direction, radially inward from the plurality of first openings, Includes, The plurality of first openings and the plurality of second openings communicate with a chamber formed between the heat sink and the partition wall. The electric pump according to claim 1 or 2.

10. The control board is Printed circuit board and The electronic components mounted on the aforementioned printed circuit board, Includes, The electric pump according to claim 1 or 2, further comprising a heat dissipation material provided between the electronic component and the heat sink.

11. The heat sink has a plurality of protrusions formed on the surface facing the partition wall. The electric pump according to claim 1 or 2.

12. The casing is, An intermediate casing formed by the aforementioned mold material, A pump casing attached to one end of the intermediate casing in the axial direction, which together with the intermediate casing covers the impeller, A substrate casing is attached to the other end of the intermediate casing in the axial direction and covers the control board together with the intermediate casing, including The electric pump according to claim 1 or 2.

13. The magnet is positioned radially inward of the stator core so as to form the radial magnetic gap between it and the stator core. The electric pump according to claim 1 or 2.

14. The magnet is positioned radially outward from the stator core so as to form the radial magnetic gap between it and the stator core. The electric pump according to claim 1 or 2.

15. The magnet is positioned on the back side of the impeller so as to form the axial magnetic gap between it and the stator core. The electric pump according to claim 1 or 2.

Images