Electrically driven pump

Abstract

To provide an electrically driven pump in which ingress of fluid into substrate chamber can be prevented and which enables simplification of a forming process and improvement of quality of the pump.SOLUTION: An electrically driven pump 1(1A-1D) comprises: a rotor 10 having an impeller 12 and a magnet 16; a stator 20 having a stator core 22 and a stator coil 24 wound around the stator core 22; a motor chamber 100 in which at least the rotor 10 is stored; a resin partitioning wall 40 which partitions the substrate chamber 200 storing a control substrate 30 and has a through-hole 42 communicating the motor chamber 100 and the substrate chamber 200; a support shaft 50 fixed by being inserted into the through-hole 42 of the partitioning wall 40 such as to extend from the motor chamber 100 to the substrate chamber 200, and which supports the rotor 10 in the motor chamber 100; and a seal ring 60 attached annularly along an outer peripheral edge of the through-hole 42 of the partitioning wall 40 so as to surround a base end part 52 of the support shaft 50 projecting on the substrate chamber 200 side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Conventionally, an electric pump has been known in which an impeller for pressurizing a fluid and a motor for rotating the impeller are disposed in the same casing. This type of electric pump includes a rotor including an impeller and a magnet, a stator including a stator core disposed between the rotor and the magnet with a magnetic gap, and a control board for controlling the power supplied to the stator coil of the stator. The control board is housed in a board chamber isolated from at least the motor chamber in which the rotor is housed.

[0003] For example, Patent Document 1 describes an electric pump including an axial member (shaft) fixed to a casing, a cylindrical bearing inserted around the axial member, a rotor formed as a separate member from the bearing and rotating integrally with the bearing, and an impeller fixed to one end of the rotor. The motor chamber housing the rotor is separated from the board chamber housing a control board by a partition wall that is part of the casing (see FIG. 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-23635 Summary of the Invention [Problem to be solved by the invention]

[0005] In the electric pump described in Patent Document 1, a partition wall that is part of the casing separates the motor chamber from the board chamber that houses the control board, thereby preventing fluid from entering the board chamber from the motor chamber (see Figure 1). The shaft member does not penetrate the casing (partition wall), and the end of the shaft member is embedded in the casing (partition wall). Here, one possible method for embedding the end of the shaft member in the casing and integrating the two is to integrally mold the resin casing and the shaft member using the metal shaft member as an insert part. However, this method requires the shaft member to be set on the movable mold side, which makes the insert molding process more complicated due to the need to suck the shaft member, and also makes the shaft member more susceptible to damage.

[0006] Another method for fixing the shaft member to the casing is to press-fit the end of the metal shaft member into a bottomed recess (a blind hole or a pocket hole) provided in the resin casing. However, this method requires a large press-fitting margin (tightening margin) because the shaft member is supported at one end, which carries the risk of cracks occurring in the recessed portion of the resin (casing).

[0007] Another possible method for fixing the shaft member to the casing is to glue a metal shaft member to a resin casing. However, with this method, there is a problem of the shaft member falling over because there is a large gap between the resin casing and the metal shaft member (loose fit).

[0008] In view of the above circumstances, at least some embodiments of the present invention aim to provide an electric pump that can prevent fluid from entering the substrate chamber and that can simplify the molding process of the resin partition portion and improve quality. [Means for solving the problem]

[0009] In accordance with at least some embodiments of the present invention, an electric pump comprises: a rotor including an impeller and a magnet; a stator including a stator core disposed with a magnetic gap between it and the magnet and a stator coil wound around the stator core; a resin partition wall that separates a motor chamber that houses at least the rotor from a board chamber that houses a control board for controlling power supplied to the stator coil, and that has a through hole that communicates between the motor chamber and the board chamber; a support shaft that is inserted through the through-hole of the partition wall and fixed so as to extend from the motor chamber to the board chamber, and that supports the rotor in the motor chamber; a seal ring provided along an outer periphery of the through hole in the partition wall portion so as to surround a base end of the support shaft protruding toward the substrate chamber; Equipped with. [Effects of the Invention]

[0010] According to at least some embodiments of the present invention, the support shaft, which is a separate part from the partition wall, is assembled to the resin partition wall, which simplifies the molding process for the resin partition wall compared to when the support shaft and partition wall are integrally molded by insert molding. Furthermore, since the support shaft is inserted into and fixed in the through hole in the partition wall, cracks around the periphery of the through hole in the partition wall and tilting of the support shaft are suppressed, thereby improving the quality of the electric pump. Furthermore, since a seal ring is provided to surround the base end of the support shaft that protrudes toward the substrate chamber, leakage of fluid through the gap between the through hole in the partition and the support shaft can be suppressed. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an axial cross-sectional view showing a schematic configuration of an electric pump according to an embodiment. [Figure 2] FIG. 10 is an axial cross-sectional view showing a schematic configuration of an electric pump according to another embodiment. [Figure 3A] FIG. 2 is a plan view of a retainer according to one embodiment. [Figure 3B] FIG. 2 is a perspective view of a retainer according to one embodiment. [Figure 4A] FIG. 10 is a plan view of a retainer according to another embodiment. [Figure 4B] FIG. 10 is a perspective view of a retainer according to another embodiment. [Figure 4C]FIG. 10 is a perspective cross-sectional view of a retainer according to another embodiment. [Figure 5A] FIG. 2 is an exploded perspective cross-sectional view showing components around a retainer of the electric pump according to the embodiment. [Figure 5B] FIG. 2 is a perspective cross-sectional view showing a configuration of a retainer and its surroundings of the electric pump according to the embodiment. [Figure 5C] FIG. 2 is a perspective view showing a configuration of a retainer and its surroundings of the electric pump according to the embodiment. [Figure 6A] FIG. 10 is an exploded perspective cross-sectional view showing components around a retainer of an electric pump according to another embodiment. [Figure 6B] FIG. 10 is a perspective cross-sectional view showing the configuration of the periphery of a retainer of an electric pump according to another embodiment. [Figure 6C] FIG. 10 is a perspective view showing a configuration around a retainer of an electric pump according to another embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing the structure of a partition wall and a seal ring of an electric pump according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0013] Fig. 1 is an axial cross-sectional view showing a schematic configuration of an electric pump 1A according to one embodiment, and Fig. 2 is an axial cross-sectional view showing a schematic configuration of an electric pump 1B according to another embodiment. Hereinafter, when referring to an electric pump according to some embodiments of the present invention including the electric pumps 1A and 1B, they will be referred to as the electric pump 1 (1A, 1B).

[0014] As shown in FIGS. 1 and 2, in some embodiments, the electric pump 1 (1A, 1B) includes a casing 2, and a motor section 6 and a pump section 8 covered by the casing 2.

[0015] The casing 2 has a fluid inlet 3 and a fluid outlet 4, and defines a motor chamber 100 that houses at least the rotating parts (rotor 10 described later) of the motor section 6 and the pump section 8, and a board chamber 200 that houses a control board 30 for controlling the electric pump 1 (1A, 1B). The motor chamber 100 and the board chamber 200 are separated from each other by a resin partition wall 40 that constitutes part of the casing 2. The partition wall 40 has a through hole 42 that connects the motor chamber 100 and the board chamber 200. A support shaft 50, which will be described later, is inserted into the through hole 42 of the partition wall 40.

[0016] In the embodiment shown in Figures 1 and 2, the casing 2 includes an upper casing 2A having a fluid inlet 3 and a fluid outlet 4, a middle casing 2B located below the upper casing 2A, and a lower casing 2C located below the middle casing 2B. The upper casing 2A and the middle casing 2B, and the middle casing 2B and the lower casing 2C are fastened together by fastening parts (not shown). The upper casing 2A and the middle casing 2B form a motor chamber 100 that covers the motor unit 6 and the pump unit 8. The middle casing 2B and the lower casing 2C form a board chamber 200 that covers the control board 30. The middle casing 2B is a resin part that includes an outer peripheral wall portion 102 of the motor chamber 100 and a partition portion 40 that separates the motor chamber 100 and the board chamber 200. In other embodiments, the middle casing 2B is a separate resin part from the resin part that forms the partition portion 40.

[0017] The motor unit 6 consumes the power supplied via the terminal 5 to rotate the impeller 12 of the pump unit 8. The power supply to the motor unit 6 is controlled by a control board 30.

[0018] 1 and 2, the pump section 8 is a centrifugal pump that utilizes centrifugal force caused by the rotation of the impeller 12. Specifically, the pump section 8 is a volute pump that has a volute chamber 9 radially outside the impeller 12. The pump section 8 may be any other type of centrifugal pump as long as it includes the impeller 12. In another embodiment, the pump section 8 is a turbine pump having guide vanes. When the pump section 8 is a turbine pump, the volute 9, whose flow path cross-sectional area gradually increases, is an optional configuration.

[0019] A region (pump chamber) in the internal space of the casing 2 where the pump section 8 is provided communicates with a fluid inlet 3 and a fluid outlet 4. The fluid taken into the pump chamber from the fluid inlet 3 is pressurized as it passes through an impeller 12 of the pump section 8 and is discharged from the fluid outlet 4. In the exemplary embodiment shown in FIGS. 1 and 2 , the fluid is guided axially to the impeller 12 via the fluid inlet 3, and after passing through the impeller 12, the fluid is guided to the fluid outlet 4 via a volute chamber 9 radially outside the impeller 12. The flow path of the volute chamber 9 gradually expands toward the circumferential position of the fluid outlet 4.

[0020] The impeller 12 includes a plurality of blades 13 arranged in the circumferential direction. An intake port 12A is formed between the leading edges of adjacent blades 13, and an outlet port 12B is formed between the trailing edges of adjacent blades 13. The intake port 12A of the impeller 12 is connected to the fluid inlet 3, and velocity energy is imparted to the fluid that flows in from the fluid inlet 3 by the rotating impeller 12. The outlet port 12B of the impeller 12 is connected to the volute chamber 9, and the fluid that has passed through the impeller 12 flows radially outward through the outlet port 12B, flows into the volute chamber 9, and flows circumferentially through the volute chamber 9 toward the fluid outlet 4. At this time, the fluid is decelerated due to the gradual expansion of the flow path of the volute chamber 9, and the velocity energy is converted into static pressure.

[0021] The impeller 12 may have a shroud 14. In the exemplary embodiment shown in Figures 1 and 2, the impeller 12 is a closed impeller and includes a shroud 14 that covers the blades 13. In other embodiments, the impeller 12 is an open impeller in which there is no shroud covering the blades 13 .

[0022] As described above, when focusing on the function of the electric pump 1 (1A, 1B), the components of the electric pump 1 (1A, 1B) are mainly classified into a motor section 6 that functions as a motor and a pump section 8 that functions as a pump. On the other hand, the electric pump 1 (1A, 1B) can also be classified into a plurality of elements from the viewpoint of physical components. The components of the electric pump 1 (1A, 1B) will be described below.

[0023] In some embodiments, as shown in Figures 1 and 2, the electric pump 1 (1A, 1B) includes a rotor 10 having an impeller 12 and a magnet 16, a stator 20 having a stator core 22 and a stator coil 24, a control board 30 housed in a board chamber 200, a resin partition section 40 separating the motor chamber 100 and the board chamber 200, and a support shaft 50 supporting the rotor 10.

[0024] The rotor 10 is supported by the support shaft 50 on the radially outer side of the support shaft 50. The support shaft 50 is a stationary shaft (fixed shaft) that is made of a hollow or solid shaft member that extends along the central axis of the rotor 10. 1 and 2, the rotor 10 is rotatably supported on the support shaft 50 via a bearing 18. The bearing 18 may be attached to the rotor 10, in which case the inner peripheral surface of the bearing 18 serves as a sliding surface for the support shaft 50, and a minute bearing gap is formed between the inner peripheral surface of the bearing 18 and the outer peripheral surface of the support shaft 50.

[0025] The rotor 10 includes the above-mentioned impeller 12 provided facing the fluid inlet 3 of the casing 2 in the axial direction, and a magnet 16 located on the opposite side of the impeller 12 from the fluid inlet 3 in the axial direction.

[0026] The electric pumps 1A and 1B differ from each other in the shape of the rotor main body 11 and the arrangement of the magnets 16. 1 is an inner rotor type in which the rotor 10 (rotor main body 11) is located radially inside the stator 20. Specifically, the rotor main body 11 extends cylindrically in the axial direction from the hub side of the impeller 12, and supports the magnet 16 so that it is located on the inner circumferential side of the stator 20 with the magnet 16 facing radially outward. 2 is an outer rotor type in which the rotor 10 (rotor main body 11) is located radially outside the stator 20. Specifically, the rotor main body 11 extends cylindrically in the axial direction from the outer periphery of the impeller 12, and supports the magnet 16 so that it is located on the outer periphery of the stator 20 with the magnet 16 facing radially inward.

[0027] The magnet 16 is a permanent magnet arranged facing the stator 20. In the embodiment shown in Figs. 1 and 2, the magnet 16 is provided so as to be exposed on the surface of the rotor 10 facing the stator 20. There may be one magnet 16 for each electric pump 1 (1A, 1B), or a magnet 16 divided into multiple pieces may be used.

[0028] In some embodiments, as shown in FIGS. 1 and 2, the stator 20 includes a stator core 22 and a stator coil 24. The stator core 22 forms a magnetic path through which magnetic flux flows when current is applied to the stator coil 24. The stator coil 24 may be wound around the teeth of the stator core 22 so as to be housed in slots provided in the stator core 22.

[0029] The stator 20 may further include a resin molding material 26 that covers the stator core 22 and the stator coil 24 . 1 and 2, the molding material 26 is molded integrally with the partition wall 40 and the outer peripheral wall 102 of the motor chamber 100 by insert molding using the stator core 22 and the stator coil 24 as insert parts. That is, the stator core 22 and the stator coil 24 are set in a mold as insert parts, and resin is injected into the mold, thereby obtaining the stator 20 in which the stator core 22 and the stator coil 24 are embedded in the resin molded body (the molding material 26, the partition wall 40, and the outer peripheral wall 102). 1, the stator core 22 and the stator coil 24 are embedded in a molding material 26 that is part of the outer peripheral wall 102 of the motor chamber 100 so as to be located radially outside the rotor 10. In contrast, in the exemplary embodiment shown in Fig. 2, the stator core 22 and the stator coil 24 are embedded in a molding material 26 that protrudes from the partition wall 40 in the axial direction toward the opposite side to the substrate chamber 200 so as to be located radially inside the rotor 10.

[0030] The stator core 22 is disposed with a magnetic gap G between it and the magnet 16 of the rotor 10. The magnetic gap G is formed over the area where the stator core 22 and the magnet 16 face each other. In the embodiment shown in Figs. 1 and 2, the annular magnetic gap G extends along the axial direction of the impeller 12 over the area where the stator core 22 and the magnet 16 face each other in the radial direction of the impeller 12.

[0031] The stator 20 faces the rotor 10 across a gap 28 in a non-contact manner. In an embodiment in which the magnets 16 are exposed on the surface of the rotor 10 and the stator 20 includes a molding material 26, an air gap 28 is formed between the magnets 16 and the molding material 26 in the radial direction, as shown in Figures 1 and 2.

[0032] The power supply to the stator coil 24 of the stator 20 is controlled by a control board 30 housed in the board chamber 200 . The control board 30 includes a printed wiring board 32 that is supported at a desired position in the board chamber 200 by a support (not shown), and at least one electronic component 34 that is mounted on the printed wiring board 32. In the exemplary embodiment shown in Figures 1 and 2, the control board 30 includes, as the electronic component 34, one or more semiconductor devices 34A and a passive element 34B that may be, for example, a capacitor.

[0033] In some embodiments, the partition wall 40, which separates at least the motor chamber 100 in which the rotor 10 is housed and the board chamber 200 in which the control board 30 is housed, constitutes part of the casing 2. In other embodiments, the partition wall 40 is housed within the casing 2 as a separate part from the casing 2. In the exemplary embodiment shown in Figures 1 and 2, as described above, the partition wall portion 40 is molded integrally with the stator 20 and the outer peripheral wall portion 102 of the motor chamber 100 by insert molding using the stator core 22 and the stator coil 24 as insert parts, thereby constituting part of the casing 2 (middle casing 2B).

[0034] 1, the partition wall 40 includes a disk portion 40A that extends radially inward from the axial end portion of the outer cylindrical portion, which includes the molding material 26 and the outer peripheral wall portion 102, on the substrate chamber 200 side, of the resin portion (middle casing 2B) of the casing 2. The disk portion 40A extends radially along the axial end face 19 of the rotor 10 on the side opposite to the fluid inlet 3 side. The disk portion 40A as the partition wall 40 forms the bottom wall of the middle casing 2B, which has a recess for receiving the rotor 10. 2, the partition wall 40 includes a cylindrical raised portion 40B in the resin portion (middle casing 2B) of the casing 2, which is surrounded by the rotor 10 on the radially inner side of the rotor 10. Radially outward from the raised portion 40B is an annular recess formed in the middle casing 2B to receive the rotor main body 11. The raised portion 40B constitutes a part of the bottom wall of the middle casing 2B as the partition wall 40.

[0035] As shown in FIGS. 1 and 2, the partition wall 40 has a through hole 42 through which the support shaft 50 is inserted. In some embodiments, the through-hole 42 is a hole concentric with the rotation center of the rotor 10, and is provided by penetrating the partition wall portion 40 along the axial direction of the rotor 10. The motor chamber 100 communicates with the substrate chamber 200 via the through-hole 42.

[0036] In some embodiments, as shown in FIGS. 1 and 2, the partition wall 40 includes an annular protrusion 44 that protrudes toward the substrate chamber 200 on the outer periphery of the through-hole 42. The annular protrusion 44 has an inner circumferential surface 45 that is concentric with the through hole 42. The inner diameter D2 of the annular protrusion 44 (the diameter of the inner circumferential surface 45) is larger than the inner diameter D1 of the through hole 42.

[0037] In the embodiment shown in FIG. 1, the partition wall portion 40 includes an annular protrusion 46 that protrudes toward the motor chamber 100 side. The annular protrusion 46 makes it easier to ensure the length L of the through hole 42 compared to when no protrusion 46 is provided, and contributes to the reliable fixation of the support shaft 50 to the partition wall portion 40.

[0038] The support shaft 50 extends from the motor chamber 100 to the board chamber 200 by passing through a resin partition wall 40 that separates the motor chamber 100 and the board chamber 200. The support shaft 50 is inserted into a through hole 42 in the partition wall 40 and fixed therein. The fit between the support shaft 50 and the through hole 42 is sufficient as long as the support shaft 50 is immovable relative to the partition wall portion 40, and may be, for example, an intermediate fit or an interference fit.

[0039] In some embodiments, the support shaft 50 is fixed by a mid-fit into the through-hole 42 of the partition wall portion 40 . The intermediate fitting of the support shaft 50 into the through hole 42 may be performed by light press-fitting. In this case, the tolerance for the fit between the support shaft 50 and the through hole 42 may be, for example, a combination of H6 and m5, or a combination of H7 and m6, for the tolerance of the outer diameter of the support shaft 50 and the tolerance of the hole diameter of the through hole 42 (JIS B 0401-1).

[0040] As shown in Figures 1 and 2, when the support shaft 50 is inserted and fixed through the through hole 42 of the partition portion 40, fluid in the motor chamber 100 can enter the board chamber 200 through the gap between the inner surface of the through hole 42 and the outer surface of the support shaft 50. Therefore, in some embodiments, the electric pump 1 (1A, 1B) includes a seal ring 60 that surrounds the base end portion 52 of the support shaft 50 that protrudes toward the substrate chamber 200 side.

[0041] The seal ring 60 is arranged in a ring shape along the outer peripheral edge of the through hole 42 in the partition portion 40, and prevents fluid from entering the substrate chamber 200 through the gap between the inner peripheral surface of the through hole 42 and the outer peripheral surface of the support shaft 50. The seal ring 60 is made of an elastomer material having elasticity. The seal ring 60 may be, for example, an O-ring having a circular cross section, or an X-ring or D-ring having a non-circular cross section.

[0042] 1 and 2 , the seal ring 60 is disposed on the inner peripheral side of the annular protrusion 44 of the partition wall portion 40 and on the outer peripheral side of the base end portion 52 of the support shaft 50. In other words, the seal ring 60 is provided in the annular space between the annular protrusion 44 and the base end portion 52 of the support shaft 50. Here, the thickness of the seal ring 60 in its natural state (half the difference between the inner and outer diameters of the seal ring) is larger than the size of the annular gap between the outer circumferential surface of the base end 52 of the support shaft 50 and the inner circumferential surface 45 of the annular protrusion 44. Therefore, when the seal ring 60 is assembled in the annular space between the annular protrusion 44 and the base end 52 of the support shaft 50, the seal ring 60 elastically deforms, and the inner circumferential portion of the seal ring 60 comes into close contact with the outer circumferential surface of the base end 52 of the support shaft 50, and the outer circumferential portion of the seal ring 60 comes into close contact with the inner circumferential surface 45 of the annular protrusion 44. Note that although FIGS. 1 and 2 show an axial gap between the seal ring 60 and the bottom surface of the annular protrusion 44, the seal ring 60 may also come into contact with the bottom surface of the recess inside the annular protrusion 44.

[0043] In some embodiments, as shown in FIGS. 1 and 2, the electric pump 1 (1A, 1B) includes a retainer 70 for holding the seal ring 60. The retainer 70 is attached to the base end portion 52 of the support shaft 50 and includes a retainer 70 provided on the opposite side of the partition wall portion 40 in the axial direction with the seal ring 60 sandwiched therebetween.

[0044] Here, examples of the configuration of the retainer 70 will be described with reference to FIGS. 3A to 4C. Fig. 3A is a plan view of retainer 70A according to one embodiment, as viewed from above (the motor chamber 100 side). Fig. 3B is a perspective view of retainer 70A according to one embodiment, as viewed obliquely from below. Fig. 4A is a plan view of a retainer 70B according to another embodiment, as viewed from above (the motor chamber 100 side). Fig. 4B is a perspective view of a retainer 70B according to another embodiment, as viewed obliquely from above. Fig. 4C is a perspective cross-sectional view of a retainer 70B according to another embodiment.

[0045] In some embodiments, as shown in Figures 3A to 4C, the retainer 70 (70A, 70B) includes a first connecting portion 72 (72A, 72B) for connecting the retainer 70 (70A, 70B) to the base end portion 52 of the support shaft 50, a retaining ring portion 74 (74, 74B) for preventing the seal ring 60 from falling off, and a second connecting portion 76 (76A, 76B) for connecting the retainer 70 to the partition portion 40.

[0046] The first connecting portion 72 (72A, 72B) is located on the inner periphery of the retainer 70 (70A, 70B) and connects the retainer 70 (70A, 70B) to the base end portion 52 of the support shaft 50 by any means including press-fitting, screwing, fitting, engaging, fitting, welding, or integral molding. 3A and 3B, the first coupling portions 72 are a plurality of retaining claws 72A that protrude radially inward from the periphery of the central hole 71 of the plate-shaped retainer 70A. When the retainer 70A is attached to the base end portion 52 of the support shaft 50, the plurality of retaining claws 72A serving as the first coupling portions 72 are elastically deformed so as to be pushed radially outward by the base end portion 52 of the support shaft 50. In this way, the retainer 70A is locked to the base end portion 52 of the support shaft 50 by the elastic force of the plurality of retaining claws 72A. 4A to 4C, the first coupling portion 72 is a holding hole 72B provided in the center of the retainer 70B. The retainer 70B is attached to the support shaft 50 with the base end portion 52 of the support shaft 50 inserted into the holding hole 72B as the first coupling portion 72. The retainer 70B may be attached to the support shaft 50 by press-fitting the base end portion 52 of the support shaft 50 into the holding hole 72B, or by insert molding (integral molding) of the retainer 70B with the support shaft 50 as an insert component.

[0047] The retaining ring portion 74 (74A, 74B) of the retainer 70 (70A, 70B) is located radially outside the first connecting portion 72 (72A, 72B), and when the retainer 70 is assembled to the electric pump 1, it faces the seal ring 60 and prevents the seal ring 60 from falling off. 3A and 3B, the retaining ring portion 74 is an upper plate portion 74A of an annular protrusion 73 provided around the central hole 71 of a plate-shaped retainer 70A. The outer diameter of the annular protrusion 73 corresponds to the inner diameter D2 (diameter of the inner circumferential surface 45) of the annular convex portion 44. As will be described in detail later with reference to FIGS. 5A and 5B, when the retainer 70 is assembled to the electric pump 1, the annular protrusion 73 is loosely fitted into the recess on the inner side of the annular convex portion 44. 4A to 4C, the retaining ring 74 is an annular protrusion 74B formed around the retaining hole 72B of the retainer 70B. The outer diameter of the annular protrusion 74B corresponds to the inner diameter D2 (diameter of the inner circumferential surface 45) of the annular protrusion 44. As will be described in detail later with reference to FIGS. 6A and 6B, when the retainer 70 is assembled to the electric pump 1, the annular protrusion 74B is fitted into a recess on the inner side of the annular protrusion 44.

[0048] The second connecting portion 76 (76A, 76B) of the retainer 70 (70A, 70B) is located radially outside the retaining ring portion 74 (74A, 74B) and connects the retainer 70 (70A, 70B) to the partition portion 40 by any means including press-fitting, threading, fitting, engaging, fitting or welding. 3A and 3B, the second coupling portion 76 is a flange 76A that extends radially outward from the outer peripheral edge of the annular protrusion 73 of the plate-shaped retainer 70A. The flange 76A is integrated with the partition wall portion 40 by welding, thereby coupling the retainer 70A to the partition wall portion 40. 4A to 4C, the second coupling portion 76 is a flange 76B extending radially outward from the outer peripheral end of the annular protrusion 74B of the retainer 70B. In one embodiment, the flange 76B couples the retainer 70B to the partition wall 40 by press-fitting the flange 76B into a recess provided in the partition wall 40. In another embodiment, in addition to or instead of press-fitting the flange 76B into the recess, the flange 76B is coupled to the partition wall 40 by welding.

[0049] Fig. 5A is an exploded perspective cross-sectional view showing components around a retainer 70A of an electric pump 1C according to one embodiment. Fig. 5B is a perspective cross-sectional view showing the configuration around a retainer 70A of an electric pump 1C according to one embodiment. Fig. 5C is a perspective view showing the configuration around a retainer 70A of an electric pump 1C according to one embodiment. Fig. 6A is an exploded perspective cross-sectional view showing components around a retainer 70B of an electric pump 1D according to one embodiment. Fig. 6B is a perspective cross-sectional view showing the configuration around a retainer 70B of an electric pump 1D according to one embodiment. Fig. 6C is a perspective view showing the configuration around a retainer 70B of an electric pump 1D according to one embodiment. 5A to 6C are inner rotor type electric pumps, similar to the electric pump 1A shown in Fig. 1. In Fig. 5A to 6C, elements common to those in Fig. 1 are designated by the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0050] In some embodiments, the electric pump 1C includes a seal ring 60 and a plate-shaped retainer 70A (see FIGS. 3A and 3B) attached to the base end 52 of the support shaft 50 to hold the seal ring 60, as shown in FIGS. 5A to 5C. The seal ring 60 is held by a retainer 70A so as to be positioned between the inner circumferential surface 45 of the annular protrusion 44 of the partition wall portion 40 and the outer circumferential surface of the base end portion 52 of the support shaft 50. The retainer 70A is attached to the base end portion 52 of the support shaft 50 by elastic deformation of multiple retaining claws 72A. The annular protrusion 73 of the retainer 70A fits into a recess defined by the inner circumferential surface 45 of the annular protrusion 44. The flange 76A of the retainer 70A is joined to the partition wall portion 40 by a weld 80 formed by thermal caulking that melts a portion of the partition wall portion 40. In the exemplary embodiment shown in FIG. 5C , the flange 76A of the retainer 70A is joined to the partition wall portion 40 by welds 80 formed at four locations in the circumferential direction.

[0051] In some other embodiments, the electric pump 1D includes a seal ring 60 and a retainer 70B (see FIGS. 4A to 4C) attached to the base end 52 of the support shaft 50 to hold the seal ring 60, as shown in FIGS. 6A to 6C. The seal ring 60 is held by a retainer 70B so as to be positioned between the inner circumferential surface 45 of the annular protrusion 44 of the partition wall 40 and the outer circumferential surface of the base end 52 of the support shaft 50. The retainer 70B has a retaining hole 72B for holding the base end 52 of the support shaft 50. The retainer 70B is coupled to the support shaft 50 by holding the base end 52 of the support shaft 50 in the retaining hole 72B. In one embodiment, the retainer 70B is coupled to the support shaft 50 by press-fitting the base end 52 of the support shaft 50 into the retaining hole 72B. In another embodiment, the retainer 70B is coupled to the support shaft 50 by insert molding the retainer 70B using the support shaft 50 as an insert part. The annular protrusion 74B of the retainer 70B fits into a recess defined by the inner circumferential surface 45 of the annular protrusion 44. In one embodiment, flange 76B of retainer 70B is press-fitted into recess 82 provided on the tip side of annular protrusion 44 of partition wall 40. Recess 82 has an inner diameter that is larger than the inner diameter of inner circumferential surface 45 of annular protrusion 44 and that is approximately the same as the outer diameter of flange 76B of retainer 70B. In another embodiment, in addition to or instead of press-fitting flange 76B into recess 82, flange 76B is joined to partition wall 40 by welding.

[0052] The characteristic configurations of the electric pump 1 (1A, 1B) according to the above-described embodiments can be summarized as follows.

[0053] [1] The electric pump 1 (1A, 1B) according to at least some embodiments of the present invention is a rotor (10) including an impeller (12) and a magnet (16); a stator (20) including a stator core (22) disposed with a magnetic gap (G) between it and the magnet (16) and a stator coil (24) wound around the stator core (22); a resin partition wall portion (40) that separates a motor chamber (100) that houses at least the rotor (10) from a board chamber (200) that houses a control board (30) for controlling the power supplied to the stator coil (22), and that has a through hole (42) that communicates between the motor chamber (100) and the board chamber (200); a support shaft (50) that is inserted into and fixed to the through-hole (42) of the partition wall (40) so as to extend from the motor chamber (100) to the base plate chamber (200), and that supports the rotor (10) within the motor chamber (100); a seal ring (60) provided in an annular shape along the outer periphery of the through hole (42) of the partition wall portion (40) so as to surround the base end portion (52) of the support shaft (50) protruding toward the substrate chamber (200); Equipped with.

[0054] According to the configuration [1] above, the support shaft (50), which is a separate part from the resin partition wall portion (40), is assembled to the partition wall portion (40). This simplifies the molding process for the resin partition wall portion (40) compared to when the support shaft and the partition wall portion are integrally molded by insert molding. In addition, since the support shaft (50) is inserted into and fixed to the through hole (42) of the partition wall portion (40), cracks around the periphery of the through hole (42) of the partition wall portion (40) and tilting of the support shaft (50) are suppressed, thereby improving the quality of the electric pump (1). Furthermore, a seal ring (60) is provided to surround the base end (52) of the support shaft (50) protruding toward the substrate chamber (100), thereby preventing fluid leakage through the gap between the through hole (42) of the partition portion (40) and the support shaft (50).

[0055] [2] In some embodiments, in the configuration of [1] above, The partition wall (40) includes an annular protrusion (44) provided on the outer periphery of the through hole (42) so as to protrude toward the substrate chamber (200), The seal ring (60) is disposed on the inner peripheral side of the annular projection (44) and on the outer peripheral side of the base end (52) of the support shaft (50).

[0056] According to the configuration [2], an annular space for assembling the seal ring (60) can be easily formed between the annular protrusion (44) of the partition wall (40) and the base end (52) of the support shaft (50). Furthermore, the space in the board chamber (200) on the outer periphery of the annular protrusion (44) can be used as a space for arranging the electronic components (34) of the control board (30). Therefore, the electric pump (1) can be made smaller.

[0057] [3] In some embodiments, in the configuration of [1] or [2] above, The electric pump (1) The electric pump includes a retainer (70) that is provided on the opposite side of the partition wall (40) across the seal ring (60) in the axial direction of the electric pump (1) and that holds the seal ring (60).

[0058] According to the configuration [3] above, the retainer (70) prevents the seal ring (60) from falling off, thereby more reliably preventing fluid leakage from the motor chamber (100) to the base chamber (200), thereby improving the reliability of the electric pump (1).

[0059] [4] In some embodiments, in the configuration of [3] above, The retainer (70; 70A, 70B) is a first coupling portion (72; 72A, 72B) coupled to the base end portion (52) of the support shaft (50); a retaining ring portion (74; 74A, 74B) located radially outward of the first connecting portion (72; 72A, 72B) for preventing the seal ring (60) from falling off; a second coupling portion (76; 76A, 76B) located radially outward of the retaining ring portion (74; 74A, 74B) and coupled to the partition wall portion (40); Includes.

[0060] According to the configuration [4] above, by connecting the retainer (70) to the base end (52) of the support shaft (50) and the partition wall (40), the seal ring (60) can be reliably held by the retainer (70).

[0061] [5] In some embodiments, in any of the configurations [1] to [4] above, The support shaft (50) is fixed to the partition wall (40) by intermediate fitting into the through hole (42) of the partition wall (40).

[0062] According to the configuration [5] above, the intermediate fit makes it possible to immobilize the support shaft 10 relative to the partition wall 40. Furthermore, compared to an interference fit with a relatively large press-fitting allowance, the risk of cracks occurring around the periphery of the through hole 42 of the partition wall 40 can be reduced.

[0063] [6] In some embodiments, in any of the configurations [1] to [5] above, The partition wall (40) is molded integrally with the stator (20) by insert molding using the stator core (22) and the stator coil (24) as insert parts.

[0064] According to the configuration [6] above, the partition wall portion (40) having the through hole (42) through which the support shaft (50) is inserted and fixed is integrally molded with the stator (20), thereby reducing the number of parts and thereby reducing manufacturing costs.

[0065] [7] In some embodiments, in any of the configurations [1] to [6] above, The stator (20) includes a molding material (26) that covers a stator core (22) and a stator coil (24). The molding material (26) is provided integrally with the outer peripheral wall (102) of the motor chamber (100) and the partition wall (40).

[0066] According to the configuration [7] above, the partition wall portion (40) having the through hole (42) through which the support shaft (50) is inserted and fixed is integrally formed with the molding material (26) of the stator (20) and the outer peripheral wall portion (102) of the motor chamber (100), thereby reducing the number of parts and thereby reducing manufacturing costs.

[0067] [8] In some embodiments, in the configuration of [6] above, The stator core (22) and the stator coil (24) are embedded in a molding material (26) that is part of the outer peripheral wall (102) of the motor chamber (100) so as to be located radially outside the rotor (10).

[0068] According to the configuration [8] above, for the reasons described in [7] above, it is possible to realize an inner rotor type electric pump (1A) in which the rotor (10) is located radially inside the stator (20) with a small number of parts.

[0069] [9] In some embodiments, in the configuration of [7] above, The stator core (22) and the stator coil (24) are embedded in a molding material (26) that protrudes axially from the partition wall (40) toward the opposite side from the substrate chamber (100) so as to be located radially inside the rotor (10).

[0070] According to the configuration [9] above, for the reasons described in [7] above, it is possible to realize an outer rotor type electric pump (1B) in which the rotor (10) is located radially outside the stator (20) with a small number of parts.

[0071] Although the electric pump 1 (1A, 1B) according to several embodiments has been described above, the present invention also encompasses the following modifications in addition to the above-described embodiments.

[0072] FIG. 7 is a cross-sectional view showing the structure around the partition wall 40 and the seal ring 60 of the electric pump 1 according to a modified example. 7, in some embodiments, the partition wall 40 has a circular recess 48 provided in the surface 41 facing the substrate chamber 200, and the through hole 42 opens into the bottom surface of the circular recess 48. The configuration in which the partition wall 40 has the circular recess 48 is in contrast to the configuration in which the partition wall 40 has the annular protrusion 44 shown in FIGS. 1, 2, and 5A to 6C. The circular recess 48 is concentric with the through hole 42 and has a diameter larger than the inner diameter D1 of the through hole 42. The seal ring 60 is assembled in the annular gap between the inner circumferential surface of the circular recess 48 and the outer circumferential surface of the base end 52 of the support shaft 50. [Explanation of symbols]

[0073] 1(1A~1D): Electric pump 10: Rotor 12: Impeller 16: Magnet 20: Stator 22: Stator core 24: Stator coil 26:Molding material 30: Control board 40: Partition wall part 42:Through hole 44: Annular convex part 50: Support shaft 52: Proximal end 60: Seal ring 70 (70A, 70B): Retainer 72: 1st joint 74:Retaining ring part 76:Second joint 100: Motor room 102: Outer wall 200: Substrate room

Claims

1. a rotor including an impeller and a magnet; a stator including a stator core disposed with a magnetic gap between it and the magnet and a stator coil wound around the stator core; a resin partition wall that separates a motor chamber that houses at least the rotor from a board chamber that houses a control board for controlling power supplied to the stator coil, and that has a through hole that communicates between the motor chamber and the board chamber; a support shaft that is inserted through the through hole of the partition wall and fixed to the motor chamber so as to extend from the motor chamber to the board chamber, and that supports the rotor in the motor chamber; a seal ring provided along an outer circumferential edge of the through hole in the partition wall portion so as to surround a base end of the support shaft protruding toward the substrate chamber; An electric pump comprising:

2. the partition wall portion includes an annular protrusion provided on an outer periphery of the through hole so as to protrude toward the substrate chamber, The seal ring is disposed on the inner peripheral side of the annular protrusion and on the outer peripheral side of the base end portion of the support shaft. The electric pump according to claim 1 .

3. a retainer provided on the opposite side of the partition wall with the seal ring sandwiched between them in the axial direction of the electric pump, for holding the seal ring; The electric pump according to claim 1 or 2.

4. The retainer is a first coupling portion coupled to the base end portion of the support shaft; a retaining ring portion located radially outward of the first coupling portion and configured to prevent the seal ring from falling off; a second coupling portion located radially outward of the retaining ring portion and coupled to the partition wall portion; Contains The electric pump according to claim 3.

5. The support shaft is fixed to the partition wall by intermediate fitting into the through hole of the partition wall. The electric pump according to claim 1 or 2.

6. The partition wall is integrally molded with the stator by insert molding using the stator core and the stator coil as insert parts. The electric pump according to claim 1 or 2.

7. the stator includes a molding material that covers the stator core and the stator coil, The molding material is provided integrally with the outer peripheral wall portion of the motor chamber and the partition wall portion. The electric pump according to claim 1 or 2.

8. The stator core and the stator coil are embedded in the molding material as part of the outer circumferential wall of the motor chamber so as to be positioned radially outside the rotor. The electric pump according to claim 7.

9. The stator core and the stator coil are embedded in the molding material that protrudes from the partition wall portion in the axial direction toward the opposite side of the substrate chamber so as to be located radially inside the rotor. The electric pump according to claim 7.

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