Pump

Abstract

A pump is provided with: a rotor capable of rotating about a central axis; a stator radially facing the rotor with a gap therebetween; an impeller part connected to one side of the rotor in the axial direction; a housing having a rotor housing part in which the rotor is housed; and a fixed shaft extending in the axial direction and rotatably supporting the rotor. The housing has: a rotor support part that supports the rotor from one side in the axial direction; an impeller housing part in which the impeller part is housed, the interior of which is connected to the interior of the rotor housing part; and a first suction port part that opens inside the impeller housing part. The impeller portion has a second suction port portion that opens on one side in the axial direction. A part of the fixed shaft is exposed at the second suction port part.

Description

Technical Field

[0001] The present invention relates to a pump. Background Art

[0002] Conventionally, there is known a pump including a rotor that rotates about a support shaft serving as a fixed shaft (for example, Patent Document 1). Prior art literature Patent Literature

[0003] Patent Document 1: International Publication No. 2012 / 042971 Summary of the Invention

[0004] In the above-mentioned pump, there is a problem that heat is generated due to friction between the fixed shaft and the rotor. Therefore, in the above-mentioned pump, it is required to improve the heat dissipation performance of the fixed shaft.

[0005] In view of the above circumstances, one object of the present invention is to provide a pump having a structure capable of improving heat dissipation of a fixed shaft.

[0006] One embodiment of the pump of the present invention comprises: a rotor rotatable about a central axis; a stator radially opposed to the rotor with a gap therebetween; an impeller portion connected to one axial side of the rotor; a casing having a rotor housing portion for housing the rotor therein; and a fixed shaft extending axially and supporting the rotor so as to be rotatable. The casing comprises: a rotor support portion supporting the rotor from one axial side; an impeller housing portion housing the impeller portion, the interior of which is connected to the interior of the rotor housing portion; and a first suction port portion opening inside the impeller housing portion. The impeller portion comprises a second suction port portion opening to one axial side. A portion of the fixed shaft is exposed at the second suction port portion.

[0007] According to one aspect of the present invention, heat dissipation of a fixed shaft in a pump can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view showing the pump according to the first embodiment. Figure 2 is a cross-sectional view showing the pump of the first embodiment. Figure 3 Sectional view II-II in . Figure 3 It is a cross-sectional view showing the pump according to the first embodiment. Figure 4 It is a perspective view showing a part of the bearing portion according to the first embodiment. Figure 5 This is a cross-sectional view showing a portion of the pump according to the first embodiment. Figure 6It is a perspective view showing a portion of the fixed shaft and the washer according to the first embodiment. Figure 7 It is a cross-sectional view showing the second casing and the impeller portion according to the first embodiment. Figure 8 It is a perspective view showing the second housing according to the first embodiment. Figure 9 It is a cross-sectional view showing another part of the pump according to the first embodiment. Figure 10 This is a cross-sectional view showing a portion of the procedure for fixing the first housing and the second housing to each other by welding according to the first embodiment. Figure 11 This is a cross-sectional view showing a portion of a pump according to a second embodiment. Figure 12 This is a cross-sectional perspective view showing a portion of a pump according to a third embodiment. DETAILED DESCRIPTION

[0009] Each figure shows a hypothetical central axis J of a pump according to the embodiment described below. In the following description, the axial direction of the central axis J is referred to simply as the "axial direction," the radial direction centered on the central axis J is referred to simply as the "radial direction," and the circumferential direction centered on the central axis J is referred to simply as the "circumferential direction." The Z axis shown in each figure indicates the direction in which the central axis J extends. In the following description, the side toward which the Z-axis arrow in the axial direction points (the +Z side) is referred to as the "upper side," and the side opposite to which the Z-axis arrow in the axial direction points (the -Z side) is referred to as the "lower side."

[0010] In the following embodiments, the lower side corresponds to "one side in the axial direction" and the upper side corresponds to "the other side in the axial direction". In addition, the upper side and the lower side are names used only to describe the relative positional relationship of each part, and the actual configuration relationship may be a configuration relationship other than the configuration relationship indicated by these names. Figure 2 , for convenience of explanation, cross sections at different circumferential positions on both the left and right sides of the central axis J are shown.

[0011] <First embodiment> Figure 1 and Figure 2 The pump 100 of the present embodiment shown is a water pump that delivers water W. Figure 2 As shown, the pump 100 of this embodiment includes a rotor 10, a stator 20, a fixed shaft 30, an impeller 40, a housing 50, a holding member 80, a conductive member 90, a substrate 95, and a plurality of electronic components 96. The housing 50 includes a first housing 60, a second housing 70, and a cover member 51 made of resin.

[0012] The rotor 10 is rotatable about a central axis J. The rotor 10 includes a rotor core 11, a magnet 12, a first resin portion 13, a second resin portion 14, and a bearing portion 15. Figure 3 As shown, the rotor core 11 is annular and surrounds the central axis J. The magnets 12 are fixed to the radially outer surface of the rotor core 11. A plurality of magnets 12 are provided at intervals in the circumferential direction. In this embodiment, eight magnets 12 are provided.

[0013] The first resin portion 13 is substantially cylindrical and extends in the axial direction, surrounding the central axis J. Figure 2 As shown, the first resin portion 13 covers the rotor core 11 and the plurality of magnets 12 from the radially outer side and the axially opposite sides. The rotor core 11 and the plurality of magnets 12 are embedded in the first resin portion 13. In this embodiment, the first resin portion 13 is manufactured by insert molding, using the rotor core 11 and the plurality of magnets 12 as embedded components.

[0014] The second resin portion 14 is substantially cylindrical and extends in the axial direction, surrounding the central axis J. The second resin portion 14 is located radially inward of the rotor core 11. The second resin portion 14 covers the radially inner surface of the rotor core 11. The second resin portion 14 includes a portion that sandwiches the first resin portion 13 in the axial direction. The second resin portion 14 is fixed to the first resin portion 13. In this embodiment, the second resin portion 14 is produced by insert molding, wherein the molded body including the rotor core 11, the plurality of magnets 12, and the first resin portion 13, which are integrally molded by insert molding, and the bearing portion 15 is used as an embedded component.

[0015] The bearing portion 15 is cylindrical for the fixed shaft 30 to pass through in the axial direction. In this embodiment, the bearing portion 15 is roughly cylindrical and surrounds the central axis J and extends in the axial direction. The bearing portion 15 is a portion supported by the fixed shaft 30 so as to be rotatable. The bearing portion 15 is located radially inside the second resin portion 14. The outer peripheral surface of the bearing portion 15 is fixed to the inner peripheral surface of the second resin portion 14. The bearing portion 15 is made of resin, for example. The bearing portion 15 is open on both sides in the axial direction. As Figure 4 As shown, a step portion 15d is provided on the inner circumferential surface of the lower end of the bearing portion 15. This step portion 15d has a downwardly facing stepped surface 15e. The stepped surface 15e is generally annular, surrounding the central axis J. The stepped surface 15e is, for example, perpendicular to the axial direction. The inner diameter of the portion of the bearing portion 15 located below the stepped surface 15e is larger than the inner diameter of the portion of the bearing portion 15 provided with the stepped surface 15e.

[0016] like Figure 5 As shown, the inner peripheral surface of the upper end portion of the bearing portion 15 is an inclined surface 15f. The inclined surface 15f has an annular shape surrounding the central axis J, and its inner diameter increases upward. The inclined surface 15f has the same shape as the outer peripheral surface of a truncated cone whose outer diameter increases upward.

[0017] The inner surface of the bearing portion 15 is provided with a first groove portion 15a that is open on both sides in the axial direction. The first groove portion 15a extends in the axial direction. More specifically, the first groove portion 15a extends from the lower end portion of the inclined surface 15f to the step surface 15e. The upper end portion of the first groove portion 15a opens at the inclined surface 15f. The lower end portion of the first groove portion 15a opens at the step surface 15e. Figure 4 As shown, in a cross section perpendicular to the axial direction, the inner surface of the first groove portion 15a is semicircularly concave in the radial direction. Multiple first groove portions 15a are provided at intervals in the circumferential direction. In this embodiment, there are four first groove portions 15a. In this embodiment, the multiple first groove portions 15a are evenly spaced around the circumference.

[0018] A second groove portion 15b is provided on the lower end surface of the bearing portion 15, extending from the inner circumferential surface of the bearing portion 15 to the outer circumferential surface of the bearing portion 15. In the present embodiment, the second groove portion 15b extends linearly in the radial direction. A plurality of second groove portions 15b are provided at intervals in the circumferential direction. In the present embodiment, four second groove portions 15b are provided. In the present embodiment, a plurality of second groove portions 15b are arranged at equal intervals around the circumference. The interior of the second groove portion 15b is directly or indirectly connected to the interior of the first groove portion 15a. In the present embodiment, the interior of the second groove portion 15b is indirectly connected to the interior of the first groove portion 15a via a portion of the internal space of the bearing portion 15 that is below the step surface 15e. More specifically, the radially inner end of the interior of the second groove portion 15b is indirectly connected to the lower end of the interior of the first groove portion 15a via a portion of the internal space of the bearing portion 15 that is below the step surface 15e. Alternatively, the interior of the second groove portion 15b may be directly connected to the interior of the first groove portion 15a.

[0019] like Figure 5 As shown, a third groove 15c is provided on the upper end surface of the bearing portion 15, extending from the inner circumference of the bearing portion 15 to the outer circumference of the bearing portion 15. The third groove 15c is the same as the second groove 15b except that it is provided on the upper end surface of the bearing portion 15.

[0020] like Figure 2As shown, the stator 20 and the rotor 10 face each other radially with a gap therebetween. More specifically, the stator 20 faces the rotor 10 radially with a gap therebetween and a portion of the resin forming the first housing 60. In this embodiment, the stator 20 is located radially outside the rotor 10. The stator 20 surrounds the rotor 10. At least a portion of the stator 20 is embedded in and retained by the first housing 60. In this embodiment, the stator 20 is entirely embedded in the first housing 60. The stator 20 includes a stator core 21, an insulator 22 mounted to the stator core 21, and a plurality of coils 23 mounted to the stator core 21 via the insulator 22.

[0021] The stator core 21 is located radially outside the rotor core 11 and the plurality of magnets 12 and surrounds the rotor core 11 and the plurality of magnets 12. The stator core 21 is formed by, for example, stacking a plurality of plate members in the axial direction. The plurality of plate members constituting the stator core 21 are, for example, electromagnetic steel plates. At least a portion of the stator core 21 is embedded in and retained by a first resin shell 60. In this embodiment, the stator core 21 is entirely embedded in the first shell 60. Figure 3 As shown, the stator core 21 includes: an annular core back 24 surrounding the rotor 10 ; a plurality of teeth 25 extending radially inward from the core back 24 ; and a protrusion 26 protruding radially outward from the core back 24 .

[0022] The core back 24 has a generally annular shape centered on the central axis J. The radial dimension between the inner and outer circumferential surfaces of the core back 24, i.e., the radial thickness of the core back 24, is smaller than the circumferential dimension of the portion of the teeth 25 connected to the core back 24, i.e., the radially outer ends of the teeth 25. The teeth 25 are arranged at intervals in the circumferential direction. More specifically, the teeth 25 are arranged at equal intervals around the circumference. In this embodiment, six teeth 25 are provided.

[0023] The protrusion 26 is roughly trapezoidal in shape, with the circumferential dimension increasing toward the radially outer side when viewed in the axial direction. In the present embodiment, the axial dimension of the protrusion 26 is the same as the axial dimension of the core back 24 and the axial dimension of the tooth 25. The protrusion 26 has a core recess 26a that is recessed radially inward from the radially outer side of the protrusion 26. In the present embodiment, the core recess 26a is a groove that extends in the axial direction and is open on both sides of the axial direction. The interior of the core recess 26a is roughly rectangular when viewed in the axial direction. The core recess 26a is provided in the circumferential center portion of the radially outer surface of the protrusion 26. As Figure 2 As shown, the upper portion of the core recess 26a is filled with the resin constituting the first case 60. The lower portion of the core recess 26a is a void portion that is not filled with the resin.

[0024] like Figure 3As shown, multiple protrusions 26 are provided at intervals in the circumferential direction. In this embodiment, four protrusions 26 are provided. Each protrusion 26 is connected to a portion of the core back 24 located between circumferentially adjacent teeth 25. Therefore, even with the protrusions 26, the flow of magnetic flux between the core back 24 and the teeth 25 is less likely to be obstructed. Each protrusion 26 is connected to the circumferential center of each portion of the core back 24 located between circumferentially adjacent teeth 25. The four protrusions 26 include a pair of protrusions 26 arranged circumferentially with one tooth 25 between them, and a pair of protrusions 26 arranged circumferentially with another tooth 25 between them. The tooth 25 circumferentially located between a pair of protrusions 26 and the tooth 25 circumferentially located between the other pair of protrusions 26 are arranged radially with the center axis J between them. The plurality of coils 23 are attached to the plurality of teeth 25 via the insulator 22. The plurality of coils 23 are electrically connected to the substrate 95 via the conductive member 90.

[0025] like Figure 2 As shown, the fixed shaft 30 extends axially. More specifically, the fixed shaft 30 has a generally cylindrical shape, extending axially about the central axis J. The fixed shaft 30 is located radially inward of the bearing 15 of the rotor 10. The fixed shaft 30 axially passes through the radially inner side of the bearing 15. The fixed shaft 30 protrudes axially further than the bearing 15. The fixed shaft 30 is loosely fitted radially inward of the bearing 15. The fixed shaft 30 supports the inner circumferential surface of the bearing 15, thereby rotatably supporting the rotor 10.

[0026] The upper end of the fixed shaft 30 is embedded in and retained by a shaft retaining portion 69c, described later, of the first housing 60. The fixed shaft 30 extends downward from the shaft retaining portion 69c. The lower end of the fixed shaft 30 is located below the rotor housing 64, described later. A pair of shaft recesses 31 are provided in the portion of the fixed shaft 30 embedded in the shaft retaining portion 69c, radially interposing the central axis J therebetween. Since a portion of the resin constituting the shaft holding portion 69 c is positioned within the pair of shaft recesses 31 , the fixed shaft 30 is prevented from coming off the shaft holding portion 69 c .

[0027] The fixed shaft 30 has a recess 33. The recess 33 is provided in a portion of the fixed shaft 30 that is exposed to the second suction port portion 44 described later. In the present embodiment, the recess 33 is recessed upward from the lower end surface of the fixed shaft 30. The recess 33 is, for example, circular with the central axis J as the center when viewed in the axial direction. The lower portion of the recess 33 is a tapered portion 33a. The inner diameter of the tapered portion 33a increases as it goes downward. The inner surface of the tapered portion 33a has the same shape as the outer peripheral surface of a truncated cone whose outer diameter increases toward the lower side. As Figure 6As shown, a flat surface 34 is provided at the lower end of the outer circumferential surface of the fixed shaft 30. Flat surface 34 is a plane perpendicular to the radial direction. Flat surface 34 is formed by D-cutting the lower end of the fixed shaft 30. Flat surface 34 is located radially inward of the outer circumferential surface of the portion of the fixed shaft 30 above flat surface 34 and the arc-shaped surface connected to flat surface 34 in the circumferential direction.

[0028] like Figure 2 As shown, the impeller portion 40 is connected to the lower side of the rotor 10. When the rotor 10 rotates about the central axis J, the impeller portion 40 rotates about the central axis J. The impeller portion 40 is made of resin. The impeller portion 40 has a base 41, a shroud portion 42, and a plurality of blade portions 43. In this embodiment, the base 41 is connected to the lower end of the second resin portion 14. The second resin portion 14 and the base 41 are part of the same single component. The base 41 is manufactured simultaneously when the second resin portion 14 is manufactured by insert molding. The base 41 is annular and surrounds the central axis J. In this embodiment, the base 41 is roughly annular and is centered on the central axis J. The radial inner edge portion 41a of the base 41 protrudes further downward than the portion of the base 41 located radially outside the radial inner edge portion 41a. The radial inner edge portion 41a is cylindrical and opens downward. The outer diameter of the radial inner edge portion 41a decreases as it moves downward. The inside of the radially inner edge portion 41a is connected to the lower end portion of the inside of the second resin portion 14. The outer diameter of the base portion 41 is larger than the outer diameter of the lower end portion of the second resin portion 14.

[0029] In this embodiment, the shield portion 42 is separated from the base portion 41. The shield portion 42 is arranged at a distance from the lower side of the base portion 41. The shield portion 42 is annular with the central axis J as the center. The plurality of blade portions 43 are located between the base portion 41 and the shield portion 42 in the axial direction. Figure 7 As shown, the plurality of blades 43 are arranged at intervals in the circumferential direction. The plurality of blades 43 are located on the opposite side (-θ side) to the side (+θ side) on which the rotating impeller 40 advances in the circumferential direction as they go radially outward. Figure 7 The arrow θ shown in FIG. 1 shows the direction in which the impeller 40 rotates together with the rotor 10. The side indicated by the arrow θ (+θ side) is the side in which the rotating impeller 40 moves forward. The plurality of blades 43 are curved when viewed in the axial direction. Figure 2 As shown, the lower ends of the plurality of blades 43 are connected to the shroud 42. In this embodiment, the shroud 42 and the plurality of blades 43 are part of the same single component. The upper ends of the plurality of blades 43 are in contact with the base 41.

[0030] The impeller portion 40 has a second suction port portion 44 that is open on the lower side. The second suction port portion 44 is an opening portion on the lower side of the shroud portion 42. The second suction port portion 44 protrudes downwardly from the portion of the shroud portion 42 that is located radially outside the second suction port portion 44. The second suction port portion 44 is cylindrical and opens downwardly. In the present embodiment, the second suction port portion 44 is a circle centered on the central axis J when viewed in the axial direction. The inner diameter of the second suction port portion 44 is larger than the inner diameter of the base 41 and the inner diameter of the first suction port portion 74a described later. The second suction port portion 44 is arranged opposite to the upper side of the first suction port portion 74a. The interior of the second suction port portion 44 is connected to the interior of the first suction port portion 74a.

[0031] The impeller portion 40 has a second discharge port portion 45 that opens radially outward. Figure 7 As shown, the second discharge ports 45 are provided between radially outer ends of circumferentially adjacent blades 43. Water W drawn into the impeller 40 through the first suction port 74a described later is discharged radially outward from the second discharge ports 45.

[0032] like Figure 1 As shown in FIG. 1 , in this embodiment, the first housing 60 is a substantially cylindrical member centered on the central axis J. Figure 2 As shown, the first housing 60 includes a rotor housing portion 64 that houses the rotor 10, a substrate housing portion 65 that houses the substrate 95, and a partition 69 that separates the interior of the rotor housing portion 64 from the interior of the substrate housing portion 65. In other words, the housing 50 includes the rotor housing portion 64, the substrate housing portion 65, and the partition 69.

[0033] The rotor housing 64 is cylindrical, surrounding the central axis J and opening at the bottom. In this embodiment, the rotor housing 64 is roughly cylindrical, centered on the central axis J and opening at the bottom. The upper portion of the wall portion constituting the rotor housing 64 is formed by the partition 69. The rotor housing 64 includes a first circumferential wall portion 64a. The first circumferential wall portion 64a is the portion of the wall portion constituting the rotor housing 64 located radially outward from the rotor 10. The first circumferential wall portion 64a extends downward from the radially outer peripheral edge of the partition 69. The first circumferential wall portion 64a is cylindrical, surrounding the central axis J and opening at the bottom. More specifically, the first circumferential wall portion 64a is roughly cylindrical, centered on the central axis J and opening at the bottom. The stator 20 is embedded in the first circumferential wall portion 64a.

[0034] The substrate storage section 65 is located above the rotor storage section 64. The substrate storage section 65 has a cylindrical shape, surrounding the central axis J and open at the top. The lower wall portion of the wall forming the substrate storage section 65 is formed by the partition 69. The substrate storage section 65 houses the substrate 95. The substrate storage section 65 includes a second peripheral wall portion 65a as a peripheral wall portion surrounding the substrate 95 around the central axis J. The second peripheral wall portion 65a has a cylindrical shape, surrounding the central axis J and open at the top. More specifically, the second peripheral wall portion 65a has a generally cylindrical shape, centered on the central axis J and open at the top.

[0035] The radial inner side surface of the second circumferential wall portion 65a is located radially outward from the radial inner side surface of the first circumferential wall portion 64a. The radial thickness of the second circumferential wall portion 65a is smaller than the radial thickness of the first circumferential wall portion 64a. The radial thickness of the first circumferential wall portion 64a is equal to the radial distance between the radial inner side surface of the first circumferential wall portion 64a and the radial outer side surface of the first circumferential wall portion 64a. The radial thickness of the second circumferential wall portion 65a is equal to the radial distance between the radial inner side surface of the second circumferential wall portion 65a and the radial outer side surface of the second circumferential wall portion 65a. A cover member 51 is fixed to the upper end portion of the second circumferential wall portion 65a. The upper end portion of the second circumferential wall portion 65a is the upper end portion of the substrate storage portion 65. The cover member 51 closes the upper opening of the second circumferential wall portion 65a, that is, the upper opening of the substrate storage portion 65. As Figure 1 As shown, the cover member 51 is provided with a connector portion 52 that protrudes upward.

[0036] like Figure 2 As shown, the partition portion 69 is located radially inside the upper end portion of the first circumferential wall portion 64a. The radial outer edge portion of the partition portion 69 is connected to the radial inner edge portion of the first circumferential wall portion 64a. The partition portion 69 covers the rotor 10 from the upper side. The partition portion 69 has a first partition wall portion 69a, a second partition wall portion 69b and a shaft retaining portion 69c. Although omitted from the illustration, in the present embodiment, the shaft retaining portion 69c is substantially rectangular. The shaft retaining portion 69c is arranged at a position through which the center axis J passes. The shaft retaining portion 69c retains the upper end portion of the fixed shaft 30. In the present embodiment, the upper end portion of the fixed shaft 30 is embedded in the shaft retaining portion 69c. The bearing portion 15 is located on the lower side of the shaft retaining portion 69c. In Figure 2 In the embodiment, the upper end surface of the bearing portion 15 is in contact with the lower surface of the shaft holding portion 69c, but the present invention is not limited thereto. The upper end surface of the bearing portion 15 may be spaced downward from the lower surface of the shaft holding portion 69c.

[0037] The first partition wall 69a and the second partition wall 69b are wall portions that axially separate the interior of the rotor housing 64 from the interior of the substrate housing 65. The first partition wall 69a and the second partition wall 69b are positioned so as to overlap with the interior of the rotor housing 64 and the interior of the substrate housing 65 when viewed in the axial direction. In this embodiment, the first partition wall 69a and the second partition wall 69b are located radially outward of the shaft retaining portion 69c. The first partition wall 69a and the second partition wall 69b are connected to the radially outer edge of the shaft retaining portion 69c. The first partition wall 69a and the second partition wall 69b are positioned at different circumferential positions.

[0038] The second partition wall portion 69b is located below the first partition wall portion 69a. The second partition wall portion 69b is located below the upper end of the shaft retaining portion 69c. The second partition wall portion 69b is located below the upper end of the fixed shaft 30. The radial inner edge of the second partition wall portion 69b is connected to the radial outer edge of the lower portion of the shaft retaining portion 69c. In this embodiment, the second partition wall portion 69b is located above the lower end of the shaft retaining portion 69c.

[0039] The axial thickness of the first partition wall portion 69a and the axial thickness of the second partition wall portion 69b are smaller than the radial thickness of the second circumferential wall portion 65a. In the present embodiment, the axial thickness of the first partition wall portion 69a and the axial thickness of the second partition wall portion 69b are smaller than the thickness of the substrate 95. In the present embodiment, the thickness of the substrate 95 refers to the axial dimension of the substrate 95. In the present embodiment, the axial thickness of the first partition wall portion 69a and the axial thickness of the second partition wall portion 69b are the same.

[0040] The axial thickness of the first partition wall portion 69a is, for example, uniform across the entire first partition wall portion 69a. The axial thickness of the second partition wall portion 69b is, for example, uniform across the entire second partition wall portion 69b. Alternatively, the first partition wall portion 69a may include portions having different axial thicknesses. The second partition wall portion 69b may also include portions having different axial thicknesses.

[0041] like Figure 1 As shown, the first housing 60 includes a large diameter housing portion 61 and a small diameter housing portion 62 connected to the upper side of the large diameter housing portion 61. The lower end of the large diameter housing portion 61 is the lower end of the first housing 60. Figure 2As shown, the upper end of the large diameter housing portion 61 is located above the upper end of the stator core 21. The large diameter housing portion 61 is composed of a portion of the first circumferential wall portion 64a. The lower end of the large diameter housing portion 61 is the lower end of the first circumferential wall portion 64a. At least a portion of the stator core 21 is embedded in the large diameter housing portion 61 and retained. In this embodiment, the entire stator core 21 is embedded in the large diameter housing portion 61. The upper end of the small diameter housing portion 62 is the upper end of the first housing 60. The outer diameter of the small diameter housing portion 62 is smaller than the outer diameter of the large diameter housing portion 61. The small diameter housing portion 62 is composed of a portion of the first circumferential wall portion 64a and the second circumferential wall portion 65a of the substrate storage portion 65.

[0042] The radially outer edge portion of the lower surface of the first housing 60 is a first welded and fixed portion 67 . The first welded fixed portion 67 is fixed to the second housing 70 by welding. The first welded fixed portion 67 has an annular shape surrounding the central axis J. More specifically, the first welded fixed portion 67 has an annular shape centered on the central axis J.

[0043] like Figure 2 As shown, the second housing 70 is located below the first housing 60. The second housing 70 is fixed to the first housing 60. In this embodiment, the second housing 70 is made of resin. The second housing 70 includes an annular bottom wall portion 71 that surrounds the central axis J and an annular wall portion 72 that protrudes upward from the radially outer edge of the bottom wall portion 71. The bottom wall portion 71 is located below the impeller portion 40. The radially outer end of the bottom wall portion 71 is located radially outward of the impeller portion 40. The annular wall portion 72 is annular in shape, surrounding the central axis J and open at the top. The annular wall portion 72 is fixed to the first housing 60. The radially outer portion of the upper opening of the annular wall portion 72 is blocked by the first housing 60, thereby forming the impeller housing 53 that houses the impeller portion 40. In other words, the housing 50 includes the impeller housing 53. The interior of the impeller housing 53 is connected to the interior of the rotor housing 64. More specifically, the interior of the radially inner portion of the impeller housing portion 53 is located below the interior of the rotor housing portion 64 and is connected to the interior of the rotor housing portion 64 .

[0044] like Figure 8 As shown, the second housing 70 includes a plurality of fixing portions 73 projecting radially outward from the annular wall portion 72. The plurality of fixing portions 73 are arranged at intervals in the circumferential direction. The plurality of fixing portions 73 are portions fixed to the device to which the pump 100 is mounted. Each fixing portion 73 is fixed to the device to which the pump 100 is mounted, for example, by a bolt that penetrates the fixing portion 73 in the axial direction.

[0045] The second housing 70 has a first suction port portion 74a and a flow path portion 76. That is, the housing 50 has a first suction port portion 74a and a flow path portion 76. The first suction port portion 74a protrudes downward from the radial inner edge portion of the bottom wall portion 71. In the present embodiment, the first suction port portion 74a is roughly cylindrical centered on the central axis J. The first suction port portion 74a opens on the lower side. The first suction port portion 74a opens inside the impeller housing portion 53. In more detail, the upper end portion of the first suction port portion 74a opens on the upper side and opens inside the impeller housing portion 53.

[0046] The flow path portion 76 is located radially outside the impeller portion 40. The flow path portion 76 is provided between the impeller portion 40 and the annular wall portion 72 in the radial direction. Figure 7 As shown, the flow path portion 76 extends circumferentially. In this embodiment, the rotor 10 and the impeller unit 40 rotate counterclockwise about the central axis J as viewed from above. The flow path width of the flow path portion 76, that is, the radial dimension of the flow path portion 76, increases toward the front side (+θ side) in the rotational direction of the impeller unit 40. The interior of the flow path portion 76 comprises a portion of the interior of the impeller housing 53.

[0047] The second housing 70 has a first discharge port portion 74b. The first discharge port portion 74b is in the shape of a tube extending from the annular wall portion 72 in a direction perpendicular to the axial direction. The downstream end of the flow path portion 76 is connected to the first discharge port portion 74b. When the rotor 10 rotates and the impeller portion 40 rotates, water W is sucked into the impeller portion 40 from the first suction port portion 74a. The water W sucked into the impeller portion 40 is discharged radially outward from the second discharge port portion 45 of the impeller portion 40, flows circumferentially along the flow path portion 76, and is discharged to the outside of the pump 100 from the first discharge port portion 74b. In addition, a portion of the water W sucked in from the first suction port portion 74a also flows into the rotor housing portion 64.

[0048] like Figure 5As shown, the water W that has flowed into the rotor housing 64 flows upward between the radial directions of the rotor 10 and the stator 20, and toward the upper side of the rotor 10. More specifically, the water W that has flowed into the rotor housing 64 flows between the radially outer side of the rotor 10 and the radially inner side of the rotor housing 64, and toward the upper side of the rotor 10. The water W that has flowed toward the upper side of the rotor 10 flows radially inward through the axial gap between the bearing 15 and the shaft retaining portion 69c, or the third groove 15c, and flows into the interior of the bearing 15. The water W that has flowed into the bearing 15 flows downward through the radial gap between the bearing 15 and the fixed shaft 30, or the first groove 15a, and flows into the portion of the bearing 15 below the first groove 15a. The water W that has flowed into the portion of the bearing 15 below the first groove 15a flows radially outward through the axial gap between the bearing 15 and the washer 32, described later, or the second groove 15b, and flows into the interior of the impeller 40.

[0049] like Figure 8 As shown, the second shell 70 has a second weld fixing portion 77 provided on the upper surface of the second shell 70. In this embodiment, the second weld fixing portion 77 is the bottom surface of the annular groove 72a provided on the upper surface of the annular wall portion 72. The second weld fixing portion 77 is in the shape of a ring around the central axis J. More specifically, the second weld fixing portion 77 is in the shape of a circular ring centered on the central axis J. Figure 1 As shown, the second fusion-bonded portion 77 is in contact with the first fusion-bonded portion 67. The second fusion-bonded portion 77 is fixed to the first fusion-bonded portion 67 by welding. That is, the second welded fixed portion 77 is welded to the first housing 60. The welding method for fixing the first welded fixed portion 67 and the second welded fixed portion 77 to each other is not particularly limited. Examples of welding methods for fixing the first welded fixed portion 67 and the second welded fixed portion 77 to each other include infrared welding, ultrasonic welding, laser welding, and spin welding.

[0050] like Figure 9As shown, the second housing 70 includes a rotor support portion 75 that supports the rotor 10 from below. Specifically, the housing 50 includes the rotor support portion 75. The rotor support portion 75 includes a support body portion 75a and a plurality of legs 75b. The support body portion 75a supports the rotor 10 from below. In this embodiment, the support body portion 75a supports the rotor 10 from below via the washer 32. The fixed shaft 30 passes axially inside the washer 32. Specifically, the pump 100 includes the washer 32 surrounding the fixed shaft 30. The washer 32 is generally annular in shape, centered on the central axis J. The washer 32 is a plate with its plate surface facing the axial direction. The washer 32 is disposed between the rotor support portion 75 and the rotor 10. In this embodiment, the washer 32 is disposed axially between the support body portion 75a and the bearing portion 15. The washer 32 contacts the upper end of the support body portion 75a and the lower end of the bearing portion 15. Thus, the rotor 10 can be appropriately supported by the support body portion 75 a via the washer 32 .

[0051] like Figure 6 As shown, the portion of the fixed shaft 30 provided with a flat surface 34 on its outer circumferential surface passes axially inside the washer 32. A straight portion 32a is provided on the inner edge of the washer 32, radially contacting or facing the flat surface 34 with a gap therebetween. The provision of the straight portion 32a allows the inner edge of the washer 32 to have approximately the same shape as the outer edge of the portion of the fixed shaft 30 provided with the flat surface 34, as viewed in the axial direction. When the washer 32 rotates circumferentially relative to the fixed shaft 30, the straight portion 32a of the washer 32 contacts the circumferential edge of the flat surface 34. This circumferentially locks the washer 32 relative to the fixed shaft 30. This prevents the washer 32 from rotating circumferentially relative to the fixed shaft 30 about the center axis J. Consequently, friction between the washer 32 and the rotor support portion 75 is suppressed. This prevents wear on the rotor support portion 75, even if the wear resistance of the portion of the rotor support portion 75 that contacts the washer 32 is lower than that of the portion of the rotor 10 that contacts the washer 32. Therefore, it is easy to use a relatively inexpensive material to form the rotor support portion 75, thereby suppressing an increase in the manufacturing cost of the pump 100. In addition, by passing the washer 32 through the fixed shaft 30, the washer 32 can be suppressed from rotating relative to the fixed shaft 30 in the circumferential direction. Therefore, the pump 100 can be assembled more easily than when the washer 32 is fixed to the fixed shaft 30 with screws or the like.

[0052] like Figure 9As shown, the support body 75a is provided with a through-hole 75c that axially extends through the support body 75a. That is, the rotor support portion 75 has a through-hole 75c that axially extends through the rotor support portion 75. In this embodiment, the through-hole 75c is circular, centered on the central axis J, when viewed in the axial direction. The inner diameter of the through-hole 75c is larger than the outer diameter of the fixed shaft 30. The inner diameter of the through-hole 75c is larger than the inner diameter of the washer 32. The provision of the through-hole 75c gives the support body 75a a cylindrical shape that is open on both sides in the axial direction. In this embodiment, the support body 75a is substantially cylindrical, centered on the central axis J and open on both sides in the axial direction.

[0053] The support body 75a includes a small-diameter portion 75d and a large-diameter portion 75e. The small-diameter portion 75d is the lower portion of the support body 75a. The large-diameter portion 75e is the upper portion of the support body 75a. The large-diameter portion 75e is connected to the upper side of the small-diameter portion 75d. The outer diameter of the large-diameter portion 75e is larger than that of the small-diameter portion 75d. The outer diameter of the large-diameter portion 75e is approximately the same as the outer diameter of the washer 32. The lower surface of the washer 32 contacts the upper end surface of the large-diameter portion 75e.

[0054] At least a portion of the support body portion 75a is located inside the impeller portion 40. In the present embodiment, the entire support body portion 75a is located inside the impeller portion 40. The interior of the impeller portion 40 includes the interior of the radially inner edge portion 41a of the base portion 41. The large diameter portion 75e in the support body portion 75a is located inside the radially inner edge portion 41a. The radially outer side surface of the large diameter portion 75e is arranged radially inwardly away from the radially inner side surface of the radially inner edge portion 41a. The small diameter portion 75d in the support body portion 75a is located below the radially inner edge portion 41a and above the second suction port portion 44.

[0055] The lower end of the fixed shaft 30 is inserted into the interior of the support body 75a, that is, into the through-hole 75c. As a result, the lower end of the fixed shaft 30 is exposed to the interior of the impeller portion 40 through the lower opening of the through-hole 75c. The lower opening of the through-hole 75c overlaps with the second suction port 44 when viewed in the axial direction. As a result, a portion of the fixed shaft 30 is exposed in the second suction port 44. Therefore, water W flowing into the interior of the impeller portion 40 from the second suction port 44 can come into contact with the portion of the fixed shaft 30 exposed in the second suction port 44. Therefore, even if heat is generated due to friction between the fixed shaft 30 and the rotor 10 due to rotation of the rotor 10, the heat can be easily dissipated from the fixed shaft 30 to the water W. As a result, the heat dissipation performance of the fixed shaft 30 can be improved.

[0056] In this specification, "a portion of the fixed shaft is exposed in the second suction port portion" means that when observing the interior of the second suction port portion from the side of the second suction port portion opening, the portion of the fixed shaft can be visually confirmed. In the present embodiment, when observing the second suction port portion 44 from the side of the second suction port portion 44 opening, that is, the lower side, the entire lower surface of the fixed shaft 30 can be visually confirmed. That is, in the present embodiment, the entire lower surface of the fixed shaft 30 is exposed in the second suction port portion 44. In this specification, "a portion of the fixed shaft is exposed in the second suction port portion" also includes the situation where a portion of the fixed shaft is located inside the second suction port portion.

[0057] In the present embodiment, the second suction port portion 44 is arranged above the first suction port portion 74a. Therefore, water W flowing into the impeller housing 53 from the first suction port 74a easily flows into the second suction port 44. This facilitates contact of the water W with the portion of the fixed shaft 30 exposed in the second suction port 44. This further improves heat dissipation of the fixed shaft 30.

[0058] In this embodiment, the fixed shaft 30 includes a recessed portion 33 provided in the portion of the fixed shaft 30 exposed to the second suction port 44. Therefore, the recessed portion 33 increases the surface area of ​​the portion of the fixed shaft 30 exposed to the second suction port 44. This increases the area of ​​the portion of the fixed shaft 30 exposed to the second suction port 44 and in contact with the water W. This facilitates heat dissipation from the fixed shaft 30 to the water W. Consequently, the heat dissipation performance of the fixed shaft 30 can be further improved.

[0059] In this embodiment, the recess 33 is recessed upward from the lower end surface of the fixed shaft 30. Therefore, a portion of the water W drawn in through the second suction port 44 can more easily come into contact with the recess 33. This facilitates heat transfer from the fixed shaft 30 to the water W. Consequently, the heat dissipation of the fixed shaft 30 can be further improved.

[0060] In the present embodiment, at least a portion of the fixed shaft 30 overlaps with the through-hole 75c when viewed in the axial direction. Therefore, a portion of the fixed shaft 30 can be appropriately exposed to the second suction port 44 via the through-hole 75c.

[0061] In this specification, the phrase "a certain object overlaps with another object when viewed in a certain direction" means that the certain object is positioned at the same position as at least a portion of the other object when viewed in the certain direction. Specifically, the phrase "at least a portion of the fixed shaft 30 overlaps with the through-hole 75c when viewed in the axial direction" means that at least a portion of the fixed shaft 30 is positioned at the same position as at least a portion of the through-hole 75c when viewed in the axial direction.

[0062] In this embodiment, the inner diameter of the through-hole 75c is larger than the outer diameter of the fixed shaft 30, and the entire fixed shaft 30 overlaps with the through-hole 75c when viewed in the axial direction. Therefore, a portion of the fixed shaft 30 can be more appropriately exposed to the second suction port 44 through the through-hole 75c. Furthermore, since the inner diameter of the through-hole 75c is larger than the outer diameter of the fixed shaft 30, water W can flow easily through the through-hole 75c. This makes it easier for the water W to come into contact with the fixed shaft 30 through the through-hole 75c. Consequently, the heat dissipation of the fixed shaft 30 can be further improved.

[0063] In this embodiment, the lower end of the fixed shaft 30 is located within the through-hole 75c. This prevents the fixed shaft 30 from protruding below the through-hole 75c. Consequently, the flow of water W within the impeller 40 is less likely to be obstructed by the lower end of the fixed shaft 30. Consequently, a decrease in the efficiency of the pump 100 can be suppressed. In addition, the water W flowing into the through-hole 75c from the second suction port 44 can be easily brought into appropriate contact with the fixed shaft 30. Therefore, the heat dissipation performance of the fixed shaft 30 can be further improved.

[0064] The plurality of legs 75 b connect the support body 75 a and the inner surface of the impeller housing 53 . like Figure 8 As shown, in this embodiment, three legs 75b are provided at intervals in the circumferential direction. Furthermore, the number of legs 75b is not particularly limited. Multiple legs 75b are arranged at equal intervals around the circumference. In this embodiment, multiple legs 75b extend upward from the inner circumferential surface of the first suction port portion 74a. The upper ends of the multiple legs 75b are connected to the support body portion 75a.

[0065] like Figure 9 As shown, the plurality of foot portions 75b respectively have a first extension portion 75f and a second extension portion 75g. The first extension portion 75f extends radially inward and upward from the inner circumference of the first suction port portion 74a. The lower surface of the first extension portion 75f faces the interior of the first suction port portion 74a. The lower surface of the first extension portion 75f is a flat inclined surface that is located on the upper side as it moves toward the radial inner side. The second extension portion 75g extends upward from the radially inner and upper end portion of the first extension portion 75f. The upper end portion of the second extension portion 75g is connected to the support body portion 75a. The upper portion of the second extension portion 75g is inserted into the interior of the impeller portion 40 from the second suction port portion 44.

[0066] In this embodiment, the support body 75a can be positioned at an appropriate position for supporting the rotor 10 by means of the plurality of legs 75b. Since the through-hole 75c is provided in the support body 75a, the plurality of legs 75b makes it easy to position the through-hole 75c at a position that overlaps with the fixed shaft 30 in the axial direction. This makes it easy to expose a portion of the fixed shaft 30 to the second suction port 44 via the through-hole 75c. Furthermore, since the support body 75a is supported by the plurality of legs 75b, the plurality of legs 75b supporting the support body 75a within the impeller housing 53 are less likely to cause obstruction (resistance) to the flow of water W than, for example, a case where the support body 75a is supported by a cylindrical support portion.

[0067] In this embodiment, water W that flows into the impeller housing 53 from the first suction port 74a flows upward and then flows into the impeller 40 from the second suction port 44. A portion of the water W that flows into the impeller 40 flows directly upward and into the through-hole 75c. The water W that flows into the through-hole 75c contacts the portion of the fixed shaft 30 located within the through-hole 75c, dissipating heat from the fixed shaft 30 to the water W. At least a portion of the water W that flows into the through-hole 75c flows from between the fixed shaft 30 and the gasket 32 ​​toward the upper side of the gasket 32. The water W that flows above the gasket 32 ​​flows radially outward in the second groove 15b, passes through the radial gap between the gasket 32 ​​and the support body 75a, and the radially inner edge 41a of the base 41, and flows to the lower side of the radially inner edge 41a of the base 41. The water W that has flowed toward the lower side of the radially inner edge portion 41 a flows toward the radially outer side and is discharged to the outside of the impeller portion 40 through the second discharge port 45 .

[0068] like Figure 2 As shown, the holding component 80 is located on the upper side of the stator 20. The holding component 80 is supported by the stator 20 from the lower side. In the present embodiment, the holding component 80 is made of resin. At least a portion of the holding component 80 is embedded in and retained in the first shell 60. In the present embodiment, substantially the entire holding component 80 is embedded in the first shell 60. The holding component 80 holds the conductive component 90. The conductive component 90 is made of metal. In the present embodiment, the conductive component 90 is a metal plate component. In the present embodiment, a plurality of conductive components 90 are arranged at intervals in the circumferential direction. The conductive component 90 electrically connects the coil 23 to the substrate 95. A portion of the conductive component 90 is embedded in and retained in the first shell 60.

[0069] The substrate 95 is housed inside the housing 50. More specifically, the substrate 95 is housed inside the substrate housing portion 65. The substrate 95 is, for example, a printed wiring board. In this embodiment, an inverter circuit that supplies power to coil 23 is provided on substrate 95. The surface of substrate 95 faces the axial direction. For example, the surface of substrate 95 is perpendicular to the axial direction. For example, substrate 95 has a generally circular plate shape. Substrate 95 is supported from below by protruding support portions 68 provided within substrate storage portion 65.

[0070] Multiple electronic components 96 are mounted on the substrate 95. These components include a first electronic component 96a, a second electronic component 96b, and a third electronic component 96c. In this embodiment, the first electronic component 96a is mounted on the upper surface of the substrate 95. For example, the first electronic component 96a is a field effect transistor (FET) that constitutes an inverter circuit. When viewed in the axial direction, the first electronic component 96a overlaps with the first partition wall portion 69a.

[0071] The second electronic component 96b is mounted on the lower surface of the substrate 95. The second electronic component 96b is an electronic component 96 with a larger axial dimension than the first electronic component 96a. The second electronic component 96b is, for example, an electrolytic capacitor. The second electronic component 96b is, for example, a roughly cylindrical shape that protrudes downward from the lower surface of the substrate 95. When viewed in the axial direction, the second electronic component 96b overlaps with the second partition wall 69b. The lower portion of the second electronic component 96b is inserted into the interior of the third recess 69j. The lower end of the second electronic component 96b is located below the upper end of the shaft retaining portion 69c and radially outward of the shaft retaining portion 69c. In this embodiment, the lower end of the second electronic component 96b is located below the upper end of the fixed shaft 30 and radially outward of the fixed shaft 30. The lower end of the second electronic component 96b is positioned upwardly away from the upper surface of the second partition wall 69b.

[0072] The third electronic component 96c is mounted on the lower surface of the substrate 95. The third electronic component 96c is an electronic component 96 having an axial dimension larger than the first electronic component 96a and smaller than the second electronic component 96b. The third electronic component 96c is, for example, a choke coil. When viewed in the axial direction, the third electronic component 96c overlaps the shaft retaining portion 69c and the fixed shaft 30. The lower end of the third electronic component 96c is positioned upwardly away from the upper surface of the shaft retaining portion 69c.

[0073] A heat-conducting member 120 is provided between the partition 69 and the substrate 95, contacting the partition 69 and the substrate 95. This allows heat from the substrate 95 to be transferred from the heat-conducting member 120 to the partition 69. Because the partition 69 separates the interior of the rotor housing 64 from the interior of the substrate housing 65, heat transferred to the partition 69 is released into the water W flowing into the rotor housing 64. This allows heat from the substrate 95 to be dissipated into the water W, the fluid conveyed by the impeller 40. Fluids such as water W have a higher thermal conductivity than air. Therefore, heat dissipation from the substrate 95 can be improved compared to dissipating heat from the substrate 95 into the air outside the pump 100. In this embodiment, heat transferred to the heat-conducting member 120 is dissipated into the water W within the rotor housing 64 via the first and second partition walls 69a, 69b.

[0074] Furthermore, for example, when dissipating heat from the substrate 95 to the air outside the pump 100, a heat sink or the like is sometimes provided on the outer surface of the housing 50 to improve heat dissipation. In contrast, according to this embodiment, since heat can be dissipated to water W, which has a higher thermal conductivity than air, heat dissipation from the substrate 95 can be improved without providing a heat sink or the like. Consequently, an increase in the number of components of the pump 100 can be suppressed while improving heat dissipation from the substrate 95.

[0075] In this embodiment, as described above, the heat of the fixed shaft 30 can be easily dissipated into the water W. Therefore, a portion of the heat transferred from the substrate 95 to the partition 69 via the heat conducting member 120 is easily dissipated from the shaft holding portion 69 c via the fixed shaft 30 into the water W. This further improves the heat dissipation performance of the substrate 95.

[0076] In this embodiment, the thermally conductive component 120 is formed from a heat dissipation gap filler. Therefore, the heat dissipation gap filler is applied to the substrate housing portion 65 in an uncured state. The substrate 95, with multiple electronic components 96 mounted thereon, is then placed within the substrate housing portion 65 while being pressed against the applied, uncured heat dissipation gap filler. This allows the substrate 95 to be in close contact with the uncured heat dissipation gap filler. Furthermore, the electronic components 96 mounted on the lower surface of the substrate 95 are easily embedded in the uncured heat dissipation gap filler, allowing the electronic components 96 mounted thereon to be in close contact with the heat dissipation gap filler. With the substrate 95 and the electronic components 96 mounted thereon in close contact with the heat dissipation gap filler, the heat dissipation gap filler is cured to form the thermally conductive component 120. This allows the substrate 95 and the electronic components 96 mounted thereon to be in close contact with the heat dissipation gap filler. Therefore, heat can be easily and appropriately transferred from the substrate 95 and the electronic component 96 to the thermally conductive member 120 , and the heat dissipation performance of the substrate 95 can be further improved.

[0077] In this embodiment, after placing substrate 95 within substrate storage section 65, an operator applies uncured thermal gap filler to partition 69 using a dispenser or the like. Then, the operator positions substrate 95, mounted with multiple electronic components 96, from above the applied uncured thermal gap filler. The operator presses substrate 95 against the uncured thermal gap filler while supporting it from below using protruding support portion 68, securing substrate 95 within substrate storage section 65. At this point, second electronic component 96b and third electronic component 96c mounted on the lower surface of substrate 95 are embedded in the uncured thermal gap filler. The operator then cures the uncured thermal gap filler, producing thermally conductive component 120 in contact with partition 69 and substrate 95. The method for curing the uncured thermal gap filler can be appropriately adopted depending on the material comprising the thermal gap filler.

[0078] In this specification, "workers, etc." include workers who perform various tasks and assembly equipment, etc. Each task may be performed by only workers, only assembly equipment, or both.

[0079] The heat dissipation gap filler constituting the thermally conductive member 120 has, for example, a viscosity sufficient to maintain its applied shape when applied in an uncured state without the application of external force. The heat dissipation gap filler constituting the thermally conductive member 120 is a material that is elastically deformable in a cured state. In a cured state, the heat dissipation gap filler constituting the thermally conductive member 120 is, for example, in a state such as rubber or clay. The heat dissipation gap filler constituting the thermally conductive member 120 is a material composed of a resin mixed with a plurality of thermally conductive fillers. The resin constituting the heat dissipation gap filler is, for example, silicone. The filler constituting the heat dissipation gap filler is, for example, ceramic. The material constituting the heat dissipation gap filler is not particularly limited.

[0080] The thermal conductivity of the heat dissipation gap filler constituting the heat conductive member 120 is higher than the thermal conductivity of the material constituting the partition 69. The thermal conductivity of the heat dissipation gap filler constituting the heat conductive member 120 is, for example, 1.5 W / (m·K) to 5 W / (m·K). The thermal conductivity of the material constituting the partition 69 is, for example, 0.2 W / (m·K) to 0.35 W / (m·K). In this embodiment, the material constituting the partition 69 is the same as the material constituting the housing 50, and is a resin.

[0081] The manufacturing method of the pump 100 of the present embodiment includes an assembly process of fixing the first housing 60 and the second housing 70. Figure 10As shown, an operator or the like assembles the rotor 10 and the impeller unit 40 to the first housing 60, and then fixes the first housing 60 and the second housing 70 to each other by welding. In this embodiment, before the first housing 60 and the second housing 70 come into contact with each other, the first welded and fixed portion 67 of the first housing 60 and the second welded and fixed portion 77 of the second housing 70 are melted by heat H. By bringing the melted first welded and fixed portions 67 and the second welded and fixed portions 77 into contact with each other in the axial direction, the first housing 60 and the second housing 70 can be fixed by welding.

[0082] In this embodiment, when fixing the first housing 60 and the second housing 70, an operator or the like uses a jig P to position the second housing 70 relative to the first housing 60 while simultaneously bringing the first housing 60 and the second housing 70 closer to each other in the axial direction. In this case, for example, the operator or the like places the first housing 60 vertically downward and brings the second housing 70 relatively closer to the first housing 60 from the vertically upper side. This prevents the washer 32 surrounding the fixed shaft 30 from falling off vertically downward.

[0083] The clamp P has a base Pa and a pin portion Pb. The base Pa is cylindrical with the center axis J as the center. The pin portion Pb extends axially from the base Pa. The front end of the pin portion Pb is formed in a conical shape. The base Pa is fitted into the first suction port portion 74a. Thus, the clamp P can be positioned radially relative to the second shell 70. The pin portion Pb passes through the through hole 75c axially and is inserted into the interior of the impeller portion 40 from the second suction port portion 44. The front end portion of the pin portion Pb is fitted into the recess 33 provided at the axial end of the fixed shaft 30. In more detail, the front end of the pin portion Pb is fitted into the tapered portion 33a of the recess 33. Thus, the clamp P can be positioned radially relative to the fixed shaft 30. Therefore, the clamp P can position the fixed shaft 30 and the second shell 70 relative to each other in the radial direction, and the second shell 70 can be arranged with good axial precision relative to the fixed shaft 30. In this state, an operator or the like brings the first housing 60 and the second housing 70 close to each other and fixes the first housing 60 and the second housing 70 to each other by welding.

[0084] As described above, in this embodiment, the rotor support portion 75 is provided with a through-hole 75c. This allows for an assembly method in which the pin portion Pb of the jig P is inserted through the through-hole 75c, the tip of the pin portion Pb is engaged with the recess 33 of the fixed shaft 30 for positioning, and the first housing 60 and second housing 70 are brought close to each other. This allows the second housing 70 to be fixed to the first housing 60 while the jig P is used to precisely align the second housing 70 with the fixed shaft 30. The fixed shaft 30 rotatably supports the rotor 10, with the impeller portion 40 connected to its axial end. Consequently, the rotor 10 and the impeller portion 40 are radially aligned relative to the fixed shaft 30. The second housing 70 is provided with a circumferentially extending flow path 76 radially outward of the impeller portion 40. Therefore, by precisely aligning the second housing 70 with the fixed shaft 30, the impeller portion 40 and the flow path 76 can be precisely aligned relative to each other. Therefore, the water W can be easily flowed from the impeller portion 40 into the flow path portion 76 , and the efficiency of the pump 100 can be improved.

[0085] <Second embodiment> like Figure 11 As shown, in the pump 200 of this embodiment, the fixed shaft 230 passes through the through hole 75c provided on the rotor support portion 75. The lower end of the fixed shaft 230 is located below the through hole 75c. Therefore, it is easy to increase the area of ​​the portion of the fixed shaft 230 exposed inside the impeller portion 40. As a result, the area of ​​the fixed shaft 230 that contacts the water W can be increased. Therefore, it is easier to release the heat of the fixed shaft 230 to the water W. Therefore, the heat dissipation of the fixed shaft 230 can be further improved. The other structures of the fixed shaft 230 are the same as the other structures of the fixed shaft 30 in the first embodiment. The other structures of the pump 200 are the same as the other structures of the pump 100 in the first embodiment.

[0086] <Third embodiment> like Figure 12 As shown, in the pump 300 of this embodiment, the leg portion 375b of the rotor support portion 375 has a curved surface 375h facing the inside (inner side) of the first suction port 74a. Therefore, the resistance of the leg portion 375b to the water W flowing in from the first suction port 74a is easily reduced. Thus, even if the foot 375b is provided, the flow of water W can be further suppressed from being obstructed by the foot 375b. In the present embodiment, the curved surface 375h is the surface on the lower side of the first extension portion 375f. The curved surface 375h is a semicircular arc-shaped surface that protrudes downward when viewed in the direction in which the first extension portion 375f extends. The curved surface 375h is located on the upper side as it moves radially inward. The other structures of the foot 375b are the same as the other structures of the foot 75b in the first embodiment. Although omitted from the illustration, in the present embodiment, the plurality of feet 375b each have a curved surface 375h. The other structures of the rotor support portion 375 are the same as the other structures of the rotor support portion 75 in the first embodiment. The other structures of the pump 300 are the same as the other structures of the pump 100 in the first embodiment.

[0087] The present invention is not limited to the above-mentioned embodiments, and other structures and methods may also be adopted within the scope of the technical idea of ​​the present invention. As long as a portion of the fixed shaft is exposed at the second suction port portion of the impeller portion, it can be exposed through any structure. For example, a portion of the fixed shaft may be exposed at the second suction port portion by constituting the rotor support portion only with a plurality of legs. In this case, the rotor is supported by the end portion on the other axial side (upper side) of the plurality of legs. In the case where a through hole is provided on the rotor support portion that passes through the rotor support portion in the axial direction, the fixed shaft may not be inserted into the through hole. For example, the end portion on one axial side (lower side) of the fixed shaft may also be located closer to the other axial side (upper side) than the through hole. A recess may not be provided in the portion of the fixed shaft exposed at the second suction port portion. The first suction port portion that opens to the interior of the impeller housing portion may be provided at any position. A gasket may not be provided around the fixed shaft.

[0088] The application of the pump of the present invention is not particularly limited. The pump can be installed on any device. For example, the pump can be installed on a vehicle. The pump can be a pump for conveying any fluid. The pump can be an oil pump for conveying oil.

[0089] Note that the present technology can adopt the following configurations. (1) A pump comprising: a rotor rotatable about a central axis; a stator radially opposed to the rotor with a gap therebetween; an impeller portion connected to one axial side of the rotor; a casing having a rotor housing portion for housing the rotor therein; and a fixed shaft extending in the axial direction and supporting the rotor so as to be rotatable, the casing having: a rotor support portion supporting the rotor from one axial side; an impeller housing portion housing the impeller portion therein, the interior of the impeller housing portion being connected to the interior of the rotor housing portion; and a first suction port portion opening in the interior of the impeller housing portion, the impeller portion having a second suction port portion opening in one axial side, a portion of the fixed shaft being exposed in the second suction port portion. (2) The pump according to (1), wherein the rotor support portion has a through hole that penetrates the rotor support portion in the axial direction, and at least a portion of the fixed shaft overlaps with the through hole when viewed in the axial direction. (3) The pump according to (2), wherein the inner diameter of the through hole is larger than the outer diameter of the fixed shaft, and the entire fixed shaft overlaps with the through hole when viewed in the axial direction. (4) The pump according to (3), wherein an end portion on one axial side of the fixed shaft is located in the through hole. (5) The pump according to (3), wherein the fixed shaft passes through the through hole, and an end portion of the fixed shaft on one axial side is located on the axial side of the through hole. (6) The pump according to any one of (2) to (5), wherein the rotor support portion has a support body portion that supports the rotor and a plurality of legs that connect the support body portion to the inner surface of the impeller housing portion, and the through hole is provided in the support body portion. (7) The pump according to (6), wherein the leg portion has a curved surface facing the inside of the first suction port portion. (8) The pump according to any one of (1) to (7), wherein the second suction port is arranged on the other axial side of the first suction port. (9) The pump according to any one of (1) to (8), wherein the fixed shaft has a recessed portion provided in a portion of the fixed shaft exposed at the second suction port. (10) The pump according to (9), wherein the recessed portion is recessed from an end surface on one axial side of the fixed shaft toward the other axial side. (11) The pump according to any one of (1) to (10), further comprising a washer surrounding the fixed shaft, the washer being provided between the rotor support portion and the rotor and being engaged with the fixed shaft in the circumferential direction.

[0090] The structures and methods described above in this specification can be appropriately combined within the range not contradictory to each other. Explanation of symbols

[0091] 10 rotor; 20 stator; 30, 230 fixed shaft; 32 washer; 33 recess; 40 impeller portion; 44 second suction port portion; 50 casing; 53 impeller housing portion; 64 rotor housing portion; 74a first suction port portion; 75, 375 rotor support portion; 75a support body portion; 75b, 375b foot portion; 75c through hole; 100, 200, 300 pump; 375h curved surface; J center axis.

Claims

1. A pump, characterized in that: have: a rotor rotatable about a central axis; a stator, the stator being radially opposed to the rotor with a gap therebetween; an impeller portion connected to one axial side of the rotor; a housing having a rotor housing portion for housing the rotor therein; as well as a fixed shaft extending in the axial direction and rotatably supporting the rotor; The housing has: a rotor support portion, the rotor support portion supporting the rotor from one axial side; an impeller housing portion, the impeller housing portion housing the impeller portion therein, the interior of the impeller housing portion being connected to the interior of the rotor housing portion; and a first suction port portion, the first suction port portion opening toward the interior of the impeller housing portion; The impeller portion has a second suction port portion that opens toward one side in the axial direction. A portion of the fixed shaft is exposed at the second suction port.

2. The pump according to claim 1, characterized in that The rotor support portion has a through hole that penetrates the rotor support portion in the axial direction. At least a portion of the fixed shaft overlaps with the through hole when viewed in the axial direction.

3. The pump according to claim 2, characterized in that The inner diameter of the through hole is larger than the outer diameter of the fixed shaft. When viewed in the axial direction, the entire fixed shaft overlaps with the through hole.

4. The pump according to claim 3, characterized in that An end portion of the fixed shaft on one axial side is located in the through hole.

5. The pump according to claim 3, characterized in that The fixed shaft passes through the through hole, An end portion of the fixed shaft on one axial side is located axially closer to one side than the through hole.

6. The pump according to claim 2, characterized in that The rotor support portion has: a supporting body portion that supports the rotor; and a plurality of legs connecting the support body and the inner surface of the impeller housing; The through hole is provided in the supporting body portion.

7. The pump according to claim 6, characterized in that The leg portion has a curved surface facing the interior of the first suction port portion.

8. The pump according to any one of claims 1 to 7, characterized in that The second suction port is arranged on the other axial side of the first suction port.

9. The pump according to any one of claims 1 to 7, characterized in that The fixed shaft has a recessed portion provided in a portion of the fixed shaft exposed at the second suction port.

10. The pump according to claim 9, characterized in that The recessed portion is recessed from an end surface on one axial side of the fixed shaft toward the other axial side.

11. The pump according to any one of claims 1 to 7, characterized in that A washer is provided, which surrounds the fixed shaft, The washer is provided between the rotor support portion and the rotor, and is clamped relative to the fixed shaft in a circumferential direction.

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