Pump

Abstract

To provide a pump having a structure which enables improvement of heat radiation performance of a fixed shaft.SOLUTION: A pump 100 includes: a rotor 10 rotatable about a central axis J; a stator that radially faces the rotor with a gap interposed therebetween; an impeller part 40 connected to one side of the rotor in an axial direction; a housing 50 having a rotor accommodating portion that accommodates the rotor therein; and a fixed shaft 30 extending in the axial direction and rotatably supporting the rotor. The housing includes: a rotor supporting portion 75 supporting the rotor from one side in the axial direction; an impeller accommodating portion 53 which accommodates the impeller part therein and has an interior connected to an interior of the rotor accommodating portion; and a first suction port 74a that is open to the interior of the impeller accommodating portion. The impeller part includes a second suction port 44 that is open to one side in the axial direction. A part of the fixed shaft is exposed to the second suction port.SELECTED DRAWING: Figure 9

Description

[Technical Field]

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

[0002] BACKGROUND ART Conventionally, there is known a pump that includes a rotor that rotates around a support shaft that is a fixed shaft (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 042971 Summary of the Invention [Problem to be solved by the invention]

[0004] In the pump described above, there is a problem in that heat is generated due to friction between the fixed shaft and the rotor, and therefore, in the pump described above, there is a need 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 that can improve the heat dissipation performance of a fixed shaft. [Means for solving the problem]

[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 section connected to one axial side of the rotor, a housing having a rotor accommodating section that accommodates the rotor, and a fixed shaft extending in the axial direction and rotatably supporting the rotor. The housing has a rotor support section that supports the rotor from one axial side, an impeller accommodating section that accommodates the impeller section and whose interior is connected to the interior of the rotor accommodating section, and a first suction port opening into the interior of the impeller accommodating section. The impeller section has a second suction port opening to one axial side. A portion of the fixed shaft is exposed to the second suction port. [Effects of the Invention]

[0007] According to one aspect of the present invention, the heat dissipation performance of the fixed shaft in the pump can be improved. [Brief explanation of the drawings]

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

[0009] Each figure shows an imaginary central axis J of a pump according to an embodiment described below. In the following description, the axial direction of the central axis J will be simply referred to as the "axial direction," the radial direction about the central axis J will be simply referred to as the "radial direction," and the circumferential direction about the central axis J will be simply referred to 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 of the axial direction toward which the arrow of the Z axis points (+Z side) will be referred to as the "upper side," and the side of the axial direction opposite to the side toward which the arrow of the Z axis points (-Z side) will be referred to as the "lower side."

[0010] In the following embodiments, the lower side corresponds to "one axial side," and the upper side corresponds to "the other axial side." Note that the terms "upper side" and "lower side" are simply names used to describe the relative positional relationships of the various components, and the actual positional relationships may be other than those indicated by these names. For the sake of explanation, FIG. 2 shows cross sections at different circumferential positions on both the left and right sides of the center axis J.

[0011] First Embodiment 1 and 2 is a water pump that delivers water W. As shown in Fig. 2, 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, all made of resin.

[0012] The rotor 10 is rotatable about a central axis J. The rotor 10 has a rotor core 11, magnets 12, a first resin portion 13, a second resin portion 14, and a bearing portion 15. As shown in FIG. 3 , 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 has a generally cylindrical shape that surrounds the central axis J and extends in the axial direction. As shown in FIG. 2 , the first resin portion 13 covers the rotor core 11 and the multiple magnets 12 from the radially outer side and both axially opposite sides. The rotor core 11 and the multiple magnets 12 are embedded in the first resin portion 13. In this embodiment, the first resin portion 13 is made by insert molding using the rotor core 11 and the multiple magnets 12 as insert members.

[0014] The second resin portion 14 has a generally cylindrical shape that surrounds the central axis J and extends in the axial direction. The second resin portion 14 is located radially inside the rotor core 11. The second resin portion 14 covers the radially inside surface of the rotor core 11. The second resin portion 14 has a portion that axially sandwiches the first resin portion 13. The second resin portion 14 is fixed to the first resin portion 13. In this embodiment, the second resin portion 14 is made by insert molding using a molded body made of 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 as an insert member.

[0015] The bearing portion 15 is cylindrical, through which the fixed shaft 30 passes in the axial direction. In this embodiment, the bearing portion 15 is substantially cylindrical, surrounding the central axis J and extending in the axial direction. The bearing portion 15 is a portion rotatably supported by the fixed shaft 30. 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, for example, resin. The bearing portion 15 is open on both sides in the axial direction. As shown in FIG. 4 , a step portion 15d having a step surface 15e facing downward is provided on the inner peripheral surface of the lower end of the bearing portion 15. The step surface 15e is substantially annular, surrounding the central axis J. The step surface 15e is, for example, perpendicular to the axial direction. The inner diameter of the portion of the bearing 15 located below the stepped surface 15e is larger than the inner diameter of the portion of the bearing 15 where the stepped surface 15e is provided.

[0016] 5, the inner peripheral surface at the upper end of bearing portion 15 is inclined surface 15f. Inclined surface 15f is annular and surrounds central axis J, and the inner diameter increases toward the top. Inclined surface 15f has a shape similar to the outer peripheral surface of a truncated cone, the outer diameter of which increases toward the top.

[0017] The inner surface of the bearing portion 15 is provided with first groove portions 15a that open to both sides in the axial direction. The first groove portions 15a extend in the axial direction. More specifically, the first groove portions 15a extend from the lower ends of the inclined surfaces 15f to the stepped surfaces 15e. The upper ends of the first groove portions 15a open to the inclined surfaces 15f. The lower ends of the first groove portions 15a open to the stepped surfaces 15e. As shown in FIG. 4, in a cross section perpendicular to the axial direction, the inner surface of the first groove portions 15a has a semicircular arc shape that is recessed radially outward. A plurality of first groove portions 15a are provided at intervals in the circumferential direction. In this embodiment, four first groove portions 15a are provided. In this embodiment, the plurality of first groove portions 15a are arranged at equal intervals around the circumference.

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

[0019] 5, a third groove portion 15c extending from the inner peripheral surface of the bearing portion 15 to the outer peripheral surface of the bearing portion 15 is provided on the upper end surface of the bearing portion 15. The third groove portion 15c is similar to the second groove portion 15b, except that it is provided on the upper end surface of the bearing portion 15.

[0020] As shown in FIG. 2 , the stator 20 faces the rotor 10 in the radial direction via a gap. More specifically, the stator 20 faces the rotor 10 in the radial direction via a gap and a portion of the resin that constitutes 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 and held in the first housing 60. In this embodiment, the stator 20 is entirely embedded in the first housing 60. The stator 20 has a stator core 21, an insulator 22 attached to the stator core 21, and a plurality of coils 23 attached to the stator core 21 via the insulator 22.

[0021] The stator core 21 is located radially outward of 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, for example, by 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 and held in a first housing 60 made of resin. In this embodiment, the stator core 21 is entirely embedded in the first housing 60. As shown in FIG. 3 , the stator core 21 has 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 substantially circular ring shape centered on the central axis J. The radial dimension between the inner peripheral surface and the outer peripheral surface of the core back 24, i.e., the radial thickness of the core back 24, is smaller than the circumferential dimension of the portions of the teeth 25 that connect to the core back 24, i.e., the radially outer ends of the teeth 25. The multiple teeth 25 are arranged at intervals in the circumferential direction. More specifically, the multiple teeth 25 are arranged at equal intervals around one circumferential circumference. In this embodiment, six teeth 25 are provided.

[0023] The protrusion 26 has a generally trapezoidal shape with a circumferential dimension that increases radially outward when viewed in the axial direction. In this 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 teeth 25. The protrusion 26 has a core recess 26a recessed radially inward from the radially outer surface of the protrusion 26. In this embodiment, the core recess 26a is a groove that extends axially and opens to both axial sides. The interior of the core recess 26a has a generally rectangular shape when viewed in the axial direction. The core recess 26a is provided in the circumferential center of the radially outer surface of the protrusion 26. As shown in FIG. 2 , an upper portion of the interior of the core recess 26a is filled with resin that constitutes the first housing 60. A lower portion of the interior of the core recess 26a is a void portion that is not filled with resin.

[0024] As shown in FIG. 3 , a plurality of 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 when the protrusions 26 are provided, 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 a circumferential center of a portion of the core back 24 located between circumferentially adjacent teeth 25. The four protrusions 26 include a pair of protrusions 26 arranged with one tooth 25 sandwiched between them in the circumferential direction, and a pair of protrusions 26 arranged with another tooth 25 sandwiched between them in the circumferential direction. The teeth 25 located between one pair of protrusions 26 in the circumferential direction and the teeth 25 located between the other pair of protrusions 26 in the circumferential direction are arranged with the central axis J sandwiched between them in the radial direction. The coils 23 are attached to the teeth 25 via the insulators 22. The coils 23 are electrically connected to the substrate 95 via the conductive member 90.

[0025] As shown in FIG. 2 , the fixed shaft 30 extends in the axial direction. More specifically, the fixed shaft 30 has a generally cylindrical shape extending in the axial direction about a central axis J. The fixed shaft 30 is located radially inside the bearing portion 15 of the rotor 10. The fixed shaft 30 passes through the radially inside of the bearing portion 15 in the axial direction. The fixed shaft 30 protrudes beyond the bearing portion 15 on both sides in the axial direction. The fixed shaft 30 is clearance-fitted into the radially inside of the bearing portion 15. The fixed shaft 30 supports the inner circumferential surface of the bearing portion 15, thereby rotatably supporting the rotor 10.

[0026] The upper end of the fixed shaft 30 is embedded in and held in a shaft holding portion 69c (described later) of the first housing 60. The fixed shaft 30 extends downward from the shaft holding portion 69c. The lower end of the fixed shaft 30 is located below a rotor accommodating portion 64 (described later). A pair of shaft recesses 31 are provided in the portion of the fixed shaft 30 embedded in the shaft holding portion 69c, with the central axis J sandwiched between them in the radial direction. As part of the resin that makes up the shaft holding portion 69c is positioned within the pair of shaft recesses 31, the fixed shaft 30 is prevented from coming off the shaft holding portion 69c.

[0027] The fixed shaft 30 has a recess 33. The recess 33 is provided in a portion of the fixed shaft 30 exposed to a second intake port portion 44 (described later). In this embodiment, the recess 33 is recessed upward from the lower end face of the fixed shaft 30. The recess 33 has, for example, a circular shape centered on the central axis J 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 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 downward. As shown in FIG. 6 , a flat surface 34 is provided at the lower end of the outer peripheral surface of the fixed shaft 30. The flat surface 34 is a plane perpendicular to the radial direction. The flat surface 34 is a surface created by D-cutting the lower end of the fixed shaft 30. The flat surface 34 is located radially inward of the outer peripheral surface of the portion of the fixed shaft 30 located above the flat surface 34 and of the arc-shaped surface circumferentially connected to the flat surface 34.

[0028] As shown in FIG. 2 , 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 portion 41, a shroud portion 42, and a plurality of blade portions 43. In this embodiment, the base portion 41 is connected to the lower end of the second resin portion 14. The second resin portion 14 and the base portion 41 are part of the same single member. The base portion 41 is formed at the same time as the second resin portion 14 is formed by insert molding. The base portion 41 has an annular shape surrounding the central axis J. In this embodiment, the base portion 41 has a substantially circular annular shape centered on the central axis J. A radially inner edge portion 41a of the base portion 41 protrudes downward from a portion of the base portion 41 that is positioned radially outward from the radially 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 downward. The interior of the radial inner edge portion 41a is connected to the lower end of the interior of the second resin portion 14. The outer diameter of the base portion 41 is larger than the outer diameter of the lower end of the second resin portion 14.

[0029] In this embodiment, the shroud portion 42 is separate from the base portion 41. The shroud portion 42 is disposed below the base portion 41 at a distance. The shroud portion 42 has an annular shape centered on the central axis J. The plurality of blade portions 43 are disposed axially between the base portion 41 and the shroud portion 42. As shown in FIG. 7, the plurality of blade portions 43 are disposed at intervals in the circumferential direction. As the plurality of blade portions 43 move radially outward, they are positioned on the opposite side (-θ side) of the circumferential direction from the side (+θ side) on which the rotating impeller portion 40 advances. The arrow θ shown in FIG. 7 indicates the direction in which the impeller portion 40 rotates together with the rotor 10. The side (+θ side) toward which the arrow θ points is the side on which the rotating impeller portion 40 advances. The plurality of blade portions 43 are curved when viewed in the axial direction. As shown in FIG. 2, the lower ends of the plurality of blade portions 43 are connected to the shroud portion 42. In this embodiment, the shroud portion 42 and the plurality of blade portions 43 are part of the same single member. The upper ends of the plurality of blade portions 43 are in contact with the base portion 41.

[0030] The impeller portion 40 has a second suction port portion 44 that opens downward. The second suction port portion 44 is an opening on the lower side of the shroud portion 42. The second suction port portion 44 protrudes downward from a portion of the shroud portion 42 that is located radially outward from the second suction port portion 44. The second suction port portion 44 is cylindrical and opens downward. In this embodiment, the second suction port portion 44 has a circular shape 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 portion 41 and the inner diameter of the first suction port portion 74a, which will be described later. The second suction port portion 44 is disposed opposite 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. As shown in Fig. 7, the second discharge port portion 45 is provided between the radially outer ends of circumferentially adjacent blade portions 43. Water W sucked into the impeller portion 40 from a first suction port portion 74a (described later) is discharged radially outward from the second discharge port portion 45.

[0032] 1, in this embodiment, the first housing 60 is a substantially cylindrical member centered on the central axis J. As shown in Fig. 2, the first housing 60 has a rotor accommodating portion 64 that accommodates the rotor 10 therein, a board accommodating portion 65 that accommodates the board 95 therein, and a partition portion 69 that separates the interior of the rotor accommodating portion 64 from the interior of the board accommodating portion 65. In other words, the housing 50 has the rotor accommodating portion 64, the board accommodating portion 65, and the partition portion 69.

[0033] The rotor accommodating portion 64 is cylindrical and surrounds the central axis J, opening downward. In this embodiment, the rotor accommodating portion 64 is generally cylindrical and centered on the central axis J, opening downward. An upper wall portion of the wall portions constituting the rotor accommodating portion 64 is formed by a partition portion 69. The rotor accommodating portion 64 has a first circumferential wall portion 64a. The first circumferential wall portion 64a is a portion of the wall portions constituting the rotor accommodating portion 64 that is located radially outward from the rotor 10. The first circumferential wall portion 64a extends downward from the radial outer peripheral edge of the partition portion 69. The first circumferential wall portion 64a is cylindrical and surrounds the central axis J, opening downward. More specifically, the first circumferential wall portion 64a is generally cylindrical and centered on the central axis J, opening downward. The stator 20 is embedded in the first circumferential wall portion 64a.

[0034] The substrate accommodating section 65 is located above the rotor accommodating section 64. The substrate accommodating section 65 is cylindrical and surrounds the central axis J, opening upward. Of the wall sections that make up the substrate accommodating section 65, the lower one is formed by a partition section 69. The substrate accommodating section 65 is a portion that accommodates a substrate 95 therein. The substrate accommodating section 65 has a second peripheral wall section 65a as a peripheral wall section that surrounds the substrate 95 around the central axis J. The second peripheral wall section 65a is cylindrical and surrounds the central axis J, opening upward. More specifically, the second peripheral wall section 65a is approximately cylindrical and centered on the central axis J, opening upward.

[0035] The radially inner surface of the second circumferential wall portion 65a is located radially outward of the radially inner 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 radially inner surface of the first circumferential wall portion 64a and the radially outer 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 radially inner surface of the second circumferential wall portion 65a and the radially outer surface of the second circumferential wall portion 65a. A lid member 51 is fixed to the upper end of the second circumferential wall portion 65a. The upper end of the second circumferential wall portion 65a is the upper end of the substrate accommodating portion 65. The lid member 51 closes the upper opening of the second circumferential wall portion 65a, i.e., the upper opening of the substrate accommodating portion 65. As shown in FIG. 1, the cover member 51 is provided with a connector portion 52 that protrudes upward.

[0036] As shown in FIG. 2, the partition 69 is located radially inside the upper end of the first circumferential wall 64a. The radial outer edge of the partition 69 is connected to the radial inner edge of the first circumferential wall 64a. The partition 69 covers the rotor 10 from above. The partition 69 has a first partition 69a, a second partition 69b, and a shaft holding portion 69c. Although not shown, in this embodiment, the shaft holding portion 69c has a substantially rectangular parallelepiped shape. The shaft holding portion 69c is located at a position where the central axis J passes through. The shaft holding portion 69c holds the upper end of the fixed shaft 30. In this embodiment, the upper end of the fixed shaft 30 is embedded in the shaft holding portion 69c. The bearing 15 is located below the shaft holding portion 69c. 2 illustrates a state in which the upper end face of the bearing portion 15 is in contact with the lower face of the shaft holding portion 69c, but this is not limiting. The upper end face of the bearing portion 15 may be spaced downward from the lower face of the shaft holding portion 69c.

[0037] The first partition wall portion 69a and the second partition wall portion 69b are walls that axially separate the interior of the rotor accommodating portion 64 and the interior of the substrate accommodating portion 65. The first partition wall portion 69a and the second partition wall portion 69b are arranged at positions that overlap the interior of the rotor accommodating portion 64 and the interior of the substrate accommodating portion 65 when viewed in the axial direction. In this embodiment, the first partition wall portion 69a and the second partition wall portion 69b are located radially outside the shaft holding portion 69c. The first partition wall portion 69a and the second partition wall portion 69b are connected to the radial outer edge portion of the shaft holding portion 69c. The first partition wall portion 69a and the second partition wall portion 69b are located at different circumferential positions from each other.

[0038] The second partition wall 69b is located lower than the first partition wall 69a. The second partition wall 69b is located lower than the upper end of the shaft holding portion 69c. The second partition wall 69b is located lower than the upper end of the fixed shaft 30. The radial inner edge of the second partition wall 69b is connected to the radial outer edge of the lower part of the shaft holding portion 69c. In this embodiment, the second partition wall 69b is located higher than the lower end of the shaft holding 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 this 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 this embodiment, the thickness of the substrate 95 refers to the axial dimension of the substrate 95. In this 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, the same over the entire first partition wall portion 69a. The axial thickness of the second partition wall portion 69b is, for example, the same over the entire second partition wall portion 69b. Note that the first partition wall portion 69a may have portions whose axial thicknesses differ from one another. The second partition wall portion 69b may have portions whose axial thicknesses differ from one another.

[0041] As shown in FIG. 1, the first housing 60 has 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. As shown in FIG. 2, 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 formed by 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 and held in the large-diameter housing portion 61. 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 constituted by a part of the first peripheral wall portion 64 a and the second peripheral wall portion 65 a of the board accommodating portion 65 .

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

[0043] As shown in FIG. 2 , 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 has an annular bottom wall portion 71 surrounding the central axis J and an annular wall portion 72 protruding 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 and surrounds the central axis J, opening upward. 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 closed by the first housing 60, thereby forming an impeller accommodating portion 53 that accommodates the impeller portion 40. In other words, the housing 50 has the impeller accommodating portion 53. The interior of the impeller accommodating portion 53 is connected to the interior of the rotor accommodating portion 64. More specifically, the interior of the radially inner portion of the impeller accommodating portion 53 is located below the interior of the rotor accommodating portion 64 and is connected to the interior of the rotor accommodating portion 64.

[0044] As shown in Fig. 8, the second housing 70 has a plurality of fixing portions 73 that protrude radially outward from the annular wall portion 72. The fixing portions 73 are arranged at intervals in the circumferential direction. The fixing portions 73 are portions that are fixed to the equipment to which the pump 100 is attached. Each fixing portion 73 is fixed to the equipment to which the pump 100 is attached, for example, by a bolt that passes through each 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. In other words, the housing 50 has the first suction port portion 74a and the 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 this embodiment, the first suction port portion 74a has a substantially cylindrical shape centered on the central axis J. The first suction port portion 74a opens downward. The first suction port portion 74a opens into the interior of the impeller accommodating portion 53. More specifically, the upper end of the first suction port portion 74a opens upward and into the interior of the impeller accommodating portion 53.

[0046] The flow path portion 76 is located radially outside the impeller portion 40. The flow path portion 76 is provided radially between the impeller portion 40 and the annular wall portion 72. As shown in FIG. 7 , the flow path portion 76 extends in the circumferential direction. In this embodiment, the rotor 10 and the impeller portion 40 rotate counterclockwise around the central axis J when viewed from above. The flow path width of the flow path portion 76, i.e., the radial dimension of the flow path portion 76, increases toward the forward side (+θ side) in the rotation direction of the impeller portion 40. The interior of the flow path portion 76 is formed by a portion of the interior of the impeller accommodating portion 53.

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

[0048] As shown in FIG. 5 , the water W that has flowed into the rotor accommodating portion 64 flows upward between the rotor 10 and the stator 20 in the radial direction, and then flows to the upper side of the rotor 10. More specifically, the water W that has flowed into the rotor accommodating portion 64 flows between the radially outer surface of the rotor 10 and the radially inner surface of the rotor accommodating portion 64, and then flows to the upper side of the rotor 10. The water W that has flowed to the upper side of the rotor 10 flows radially inward through the axial gap between the bearing portion 15 and the shaft holding portion 69c or through the third groove portion 15c, and then flows into the inside of the bearing portion 15. The water W that has flowed into the inside of the bearing portion 15 flows downward through the radial gap between the bearing portion 15 and the fixed shaft 30 or through the first groove portion 15a, and then flows into a portion of the inside of the bearing portion 15 that is located below the first groove portion 15a. Water W that flows into the part of the inside of the bearing portion 15 that is located below the first groove portion 15a flows radially outward through the axial gap between the bearing portion 15 and the washer 32 described later or through the second groove portion 15b and flows into the inside of the impeller portion 40.

[0049] As shown in FIG. 8 , the second housing 70 has a second weld-fixing portion 77 provided on the upper surface of the second housing 70. In this embodiment, the second weld-fixing portion 77 is the bottom surface of an annular groove 72a provided on the upper surface of the annular wall portion 72. The second weld-fixing portion 77 has an annular shape surrounding the central axis J. More specifically, the second weld-fixing portion 77 has an annular shape centered on the central axis J. As shown in FIG. 1 , the second weld-fixing portion 77 is in contact with the first weld-fixing portion 67. The second weld-fixing portion 77 is fixed to the first weld-fixing portion 67 by welding. In other words, the second weld-fixing portion 77 is a weld-fixing portion fixed to the first housing 60 by welding. The welding method for fixing the first weld-fixing portion 67 and the second weld-fixing portion 77 to each other is not particularly limited. The welding method for fixing the first and second welded portions 67 and 77 to each other can be, for example, infrared welding, ultrasonic welding, laser welding, spin welding, or the like.

[0050] As shown in FIG. 9 , the second housing 70 has a rotor support portion 75 that supports the rotor 10 from below. That is, the housing 50 has the rotor support portion 75. The rotor support portion 75 has a support main body portion 75a and multiple legs 75b. The support main body portion 75a is a portion that supports the rotor 10. In this embodiment, the support main body portion 75a supports the rotor 10 from below via a washer 32. The fixed shaft 30 passes axially inside the washer 32. That is, the pump 100 includes the washer 32 that surrounds the fixed shaft 30. The washer 32 has a substantially annular shape centered on the central axis J. The washer 32 has a plate shape with its plate surface facing the axial direction. The washer 32 is provided between the rotor support portion 75 and the rotor 10. In this embodiment, the washer 32 is provided axially between the support main body portion 75a and the bearing portion 15. The washer 32 is in contact with the upper end of the support body 75a and the lower end of the bearing 15. This allows the rotor 10 to be suitably supported by the support body 75a via the washer 32.

[0051] As shown in FIG. 6 , the portion of the fixed shaft 30 having the flat surface 34 on its outer circumferential surface passes through the inside of the washer 32 in the axial direction. The inner edge of the washer 32 has a straight portion 32a that is in radial contact with the flat surface 34 or faces the flat surface 34 across a gap. The straight portion 32a makes the shape of the inner edge of the washer 32 approximately the same as the shape of the outer edge of the portion of the fixed shaft 30 having the flat surface 34, as viewed in the axial direction. When the washer 32 attempts to rotate circumferentially relative to the fixed shaft 30, the straight portion 32a of the washer 32 comes into contact with the circumferential edge of the flat surface 34. This causes the washer 32 to catch circumferentially on the fixed shaft 30. This prevents the washer 32 from rotating circumferentially about the central axis J relative to the fixed shaft 30. This prevents the washer 32 from rubbing against the rotor support portion 75. As a result, wear of the rotor support portion 75 can be suppressed even if the wear resistance of the portion of the rotor support portion 75 that contacts the washer 32 is made lower than the wear resistance of the portion of the rotor 10 that contacts the washer 32. Therefore, it is easy to use a relatively inexpensive material for the rotor support portion 75, and an increase in the manufacturing cost of the pump 100 can be suppressed. Furthermore, by passing the washer 32 through the fixed shaft 30, relative rotation in the circumferential direction with respect to the fixed shaft 30 can be suppressed, making it easier to assemble the pump 100 compared to when the washer 32 is fixed to the fixed shaft 30 with screws or the like.

[0052] As shown in FIG. 9, the support main body portion 75a is provided with a through hole 75c that penetrates the support main body portion 75a in the axial direction. That is, the rotor support portion 75 has a through hole 75c that penetrates the rotor support portion 75 in the axial direction. In this embodiment, the through hole 75c has a circular shape 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. By providing the through hole 75c, the support main body portion 75a has a cylindrical shape that is open on both axial sides. In this embodiment, the support main body portion 75a has a substantially cylindrical shape that is centered on the central axis J and open on both axial sides.

[0053] The support body portion 75a has a small diameter portion 75d and a large diameter portion 75e. The small diameter portion 75d is the lower portion of the support body portion 75a. The large diameter portion 75e is the upper portion of the support body portion 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 the outer diameter 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 upper end face of the large diameter portion 75e contacts the lower surface of the washer 32.

[0054] At least a portion of the support main body portion 75a is located inside the impeller portion 40. In this embodiment, the entire support main body portion 75a is located inside the impeller portion 40. The interior of the impeller portion 40 includes the interior of the radial inner edge portion 41a of the base portion 41. The large diameter portion 75e of the support main body portion 75a is located inside the radial inner edge portion 41a. The radial outer surface of the large diameter portion 75e is provided radially inward and spaced apart from the radial inner surface of the radial inner edge portion 41a. The small diameter portion 75d of the support main body portion 75a is located below the radial 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 support main body 75a, i.e., into the through-hole 75c. As a result, the lower end of the fixed shaft 30 is exposed to the interior of the impeller unit 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 to the second suction port 44. Therefore, water W that flows into the interior of the impeller unit 40 from the second suction port 44 can come into contact with the portion of the fixed shaft 30 exposed to the second suction port 44. Therefore, even if heat is generated due to friction between the fixed shaft 30 and the rotor 10 as the rotor 10 rotates, the heat can be easily dissipated from the fixed shaft 30 to the water W. This improves the heat dissipation performance of the fixed shaft 30.

[0056] In this specification, "a portion of the fixed shaft is exposed to the second suction port" means that a portion of the fixed shaft is visible when looking at the inside of the second suction port from the side where the second suction port is open. In this embodiment, the entire lower surface of the fixed shaft 30 is visible when looking at the second suction port 44 from the side where the second suction port 44 opens, i.e., from the bottom. In other words, in this embodiment, the entire lower surface of the fixed shaft 30 is exposed to the second suction port 44. In this specification, "a portion of the fixed shaft is exposed to the second suction port" also includes the case where a portion of the fixed shaft is located inside the second suction port.

[0057] In this embodiment, the second suction port 44 is disposed above the first suction port 74a. Therefore, the water W that flows into the impeller accommodating portion 53 from the first suction port 74a easily flows into the second suction port 44. This makes it easier for the water W to come into contact with the part of the fixed shaft 30 that is exposed at the second suction port 44. Therefore, the heat dissipation performance of the fixed shaft 30 can be further improved.

[0058] In this embodiment, the fixed shaft 30 has a recess 33 provided in a portion of the fixed shaft 30 that is exposed to the second suction port 44. Therefore, the recess 33 can increase the surface area of ​​the portion of the fixed shaft 30 that is exposed to the second suction port 44. This increases the area of ​​the portion of the fixed shaft 30 that is exposed to the second suction port 44 and comes into contact with the water W. This makes it easier to release heat from the fixed shaft 30 to the water W. This further improves the heat dissipation performance of the fixed shaft 30.

[0059] In this embodiment, the recess 33 is recessed upward from the lower end face of the fixed shaft 30. This makes it easier for part of the water W drawn in from the second inlet port portion 44 to come into contact with the recess 33. This makes it easier for heat to be transferred from the fixed shaft 30 to the water W. This further improves the heat dissipation performance of the fixed shaft 30.

[0060] In this embodiment, at least a portion of the fixed shaft 30 overlaps with the through-hole 75c when viewed in the axial direction, so that a portion of the fixed shaft 30 can be suitably exposed to the second intake port portion 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 disposed at the same position as at least a part of the other object when viewed in a certain direction. In other words, the phrase "at least a part of the fixed shaft 30 overlaps with the through hole 75c when viewed in the axial direction" means that at least a part of the fixed shaft 30 is disposed at the same position as at least a part 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 suitably exposed to the second intake port portion 44 through the through hole 75c. Furthermore, because the inner diameter of the through hole 75c is larger than the outer diameter of the fixed shaft 30, it is easier for the water W to flow 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. Therefore, the heat dissipation performance 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 downward from the through-hole 75c. This makes it difficult for the lower end of the fixed shaft 30 to obstruct the flow of water W inside the impeller portion 40. This prevents a decrease in the efficiency of the pump 100. Furthermore, the water W that flows into the through-hole 75c from the second intake port portion 44 can be easily brought into suitable contact with the fixed shaft 30. This further improves the heat dissipation properties of the fixed shaft 30.

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

[0065] As shown in FIG. 9, each of the multiple leg portions 75b has a first extension portion 75f and a second extension portion 75g. The first extension portion 75f extends radially inward and upward from the inner circumferential surface 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 rises radially inward. The second extension portion 75g extends upward from the radially inward, upper end of the first extension portion 75f. The upper end of the second extension portion 75g is connected to the support main 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 by the multiple legs 75b in a suitable position for supporting the rotor 10. Because the support body 75a has the through hole 75c, the multiple legs 75b make it easy to position the through hole 75c in a position that axially overlaps with the fixed shaft 30. This makes it easy to expose a portion of the fixed shaft 30 to the second intake port 44 through the through hole 75c. Furthermore, because the support body 75a is supported by the multiple legs 75b, the multiple legs 75b that support the support body 75a within the impeller accommodating portion 53 are less likely to interfere with (resist) the flow of water W than when the support body 75a is supported by, for example, a cylindrical support portion.

[0067] In this embodiment, the water W that flows into the impeller accommodating portion 53 through the first suction port 74a flows upward and enters the interior of the impeller portion 40 through the second suction port 44. A portion of the water W that flows into the interior of the impeller portion 40 flows upward and into the through-hole 75c. The water W that flows into the through-hole 75c comes into contact with a portion of the fixed shaft 30 that is located inside the through-hole 75c, and heat is released 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 washer 32 to a position above the washer 32. The water W that flows above the washer 32 flows radially outward through the second groove portion 15b and flows below the radial inner edge 41a of the base portion 41 through the washer 32 and the radial gap between the support main body portion 75a and the radial inner edge 41a of the base portion 41. The water W that has flowed below the radially inner edge portion 41a flows radially outward and is discharged from the second discharge port portion 45 to the outside of the impeller portion 40.

[0068] As shown in FIG. 2 , the holding member 80 is located above the stator 20. The holding member 80 is supported from below by the stator 20. In this embodiment, the holding member 80 is made of resin. At least a portion of the holding member 80 is embedded and held in the first housing 60. In this embodiment, almost the entire holding member 80 is embedded in the first housing 60. The holding member 80 holds a conductive member 90. The conductive member 90 is made of metal. In this embodiment, the conductive member 90 is a sheet metal member. In this embodiment, a plurality of conductive members 90 are provided at intervals in the circumferential direction. The conductive member 90 electrically connects the coil 23 and the substrate 95. A portion of the conductive member 90 is embedded and held in the first housing 60.

[0069] The substrate 95 is accommodated inside the housing 50. More specifically, the substrate 95 is accommodated inside the substrate accommodating portion 65. The substrate 95 is, for example, a printed circuit board. In this embodiment, the substrate 95 is provided with an inverter circuit that supplies power to the coil 23. The plate surface of the substrate 95 faces the axial direction. The plate surface of the substrate 95 is, for example, perpendicular to the axial direction. The substrate 95 is, for example, approximately circular. The substrate 95 is supported from below by a protruding support portion 68 provided inside the substrate accommodating portion 65.

[0070] A plurality of electronic components 96 are attached to the substrate 95. The plurality of electronic components 96 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 attached to the upper surface of the substrate 95. The first electronic component 96a is, for example, a field effect transistor (FET) that forms an inverter circuit. The first electronic component 96a overlaps with the first partition wall portion 69a when viewed in the axial direction.

[0071] The second electronic component 96b is attached to the lower surface of the substrate 95. The second electronic component 96b is an electronic component 96 having 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 has, for example, a substantially cylindrical shape that protrudes downward from the lower surface of the substrate 95. The second electronic component 96b overlaps the second partition wall portion 69b when viewed in the axial direction. A lower portion of the second electronic component 96b is inserted into the third recess 69j. The lower end of the second electronic component 96b is located below the upper end of the shaft holding portion 69c and radially outward from the shaft holding 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 from the fixed shaft 30. The lower end of the second electronic component 96b is located above and spaced apart from the upper surface of the second partition wall portion 69b.

[0072] The third electronic component 96c is attached to the lower surface of the substrate 95. The third electronic component 96c is an electronic component 96 that has an axial dimension larger than that of the first electronic component 96a and smaller than that of the second electronic component 96b. The third electronic component 96c is, for example, a choke coil. The third electronic component 96c overlaps with the shaft holding portion 69c and the fixed shaft 30 when viewed in the axial direction. A lower end of the third electronic component 96c is positioned above and away from the upper surface of the shaft holding portion 69c.

[0073] A heat conduction member 120 is provided between the partition 69 and the substrate 95. This allows heat from the substrate 95 to be transferred from the heat conduction member 120 to the partition 69. Because the partition 69 separates the interior of the rotor housing portion 64 from the interior of the substrate housing portion 65, the heat transferred to the partition 69 is released into the water W flowing into the rotor housing portion 64. This allows the heat from the substrate 95 to be released into the water W, which is a fluid pumped by the impeller 40. Fluids such as water W have higher thermal conductivity than air. This improves the heat dissipation performance of the substrate 95 compared to when the heat from the substrate 95 is released into the air outside the pump 100. In this embodiment, the heat transferred to the heat conduction member 120 is released into the water W in the rotor housing portion 64 via the first partition 69a and the second partition 69b.

[0074] Furthermore, for example, when heat from the substrate 95 is to be released into the air outside the pump 100, a heat sink or the like may be provided on the outer surface of the housing 50 to improve heat dissipation. In contrast, according to this embodiment, heat can be released into water W, which has a higher thermal conductivity than air, so the heat dissipation of the substrate 95 can be improved without providing a heat sink or the like. Therefore, the heat dissipation of the substrate 95 can be improved while suppressing an increase in the number of parts of the pump 100.

[0075] In this embodiment, as described above, heat from the fixed shaft 30 can be easily released into the water W. Therefore, a portion of the heat transferred from the substrate 95 to the partition portion 69 via the heat conduction member 120 can be easily released from the shaft holding portion 69c 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 member 120 is made of a heat-dissipating gap filler. Therefore, by applying the heat-dissipating gap filler in an uncured state to the inside of the substrate accommodating section 65 and then placing the substrate 95, on which multiple electronic components 96 are attached, in the substrate accommodating section 65 while pressing it against the applied uncured heat-dissipating gap filler, the substrate 95 can be suitably adhered to the uncured heat-dissipating gap filler. Furthermore, the electronic components 96 attached to the lower surface of the substrate 95 can be easily embedded in the uncured heat-dissipating gap filler, and the electronic components 96 attached to the lower surface of the substrate 95 can also be suitably adhered to the heat-dissipating gap filler. By curing the heat-dissipating gap filler to form the thermally conductive member 120 while the substrate 95 and the electronic components 96 attached to the lower surface of the substrate 95 are in close contact with the heat-dissipating gap filler, the substrate 95 and the electronic components 96 attached to the lower surface of the substrate 95 can be suitably brought into contact with the heat-conducting member 120. Therefore, heat can be easily and suitably transferred from the substrate 95 and the electronic components 96 to the heat conducting member 120, and the heat dissipation properties of the substrate 95 can be further improved.

[0077] In this embodiment, a worker or the like placing the substrate 95 in the substrate accommodating section 65 applies uncured heat-dissipating gap filler to the partition section 69 using a dispenser or the like, and then brings the substrate 95, on which multiple electronic components 96 are attached, close to the applied uncured heat-dissipating gap filler from above. The worker or the like presses the substrate 95 against the uncured heat-dissipating gap filler while supporting the substrate 95 from below with the protruding support section 68, thereby fixing the substrate 95 in the substrate accommodating section 65. At this time, the second electronic component 96b and the third electronic component 96c attached to the lower surface of the substrate 95 are embedded in the uncured heat-dissipating gap filler. The worker or the like then cures the uncured heat-dissipating gap filler to create a thermally conductive member 120 in contact with the partition section 69 and the substrate 95. The method for curing the uncured heat-dissipating gap filler can be appropriately adopted depending on the material constituting the heat-dissipating gap filler.

[0078] In this specification, the term "workers, etc." includes workers who perform each task and assembly equipment, etc. Each task may be performed by a worker alone, by an assembly equipment alone, or by a worker and an assembly equipment together.

[0079] The heat dissipation gap filler constituting the heat conduction member 120 has a viscosity such that, when applied in an uncured state, it can maintain its applied shape unless an external force is applied. The heat dissipation gap filler constituting the heat conduction member 120 is a material that is elastically deformable in a cured state. The heat dissipation gap filler constituting the heat conduction member 120 is in a state similar to, for example, rubber or clay in a cured state. The heat dissipation gap filler constituting the heat conduction member 120 is a material in which multiple fillers having thermal conductivity are mixed into a resin. 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 that constitutes the heat conduction member 120 is higher than the thermal conductivity of the material that constitutes the partition 69. The thermal conductivity of the heat dissipation gap filler that constitutes the heat conduction member 120 is, for example, 1.5 W / (m·K) or more and 5 W / (m·K) or less. The thermal conductivity of the material that constitutes the partition 69 is, for example, 0.2 W / (m·K) or more and 0.35 W / (m·K) or less. In this embodiment, the material that constitutes the partition 69 is the same material that constitutes the housing 50, which is resin.

[0081] The manufacturing method of the pump 100 of this embodiment described above includes an assembly process of fixing the first housing 60 and the second housing 70 together. As shown in FIG. 10 , an operator assembles the rotor 10 and the impeller portion 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 are brought 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 portion 67 and the second welded and fixed portion 77 into contact with each other in the axial direction, the first housing 60 and the second housing 70 can be fixed to each other by welding.

[0082] In this embodiment, when fixing the first housing 60 and the second housing 70 together, a worker or the like uses a jig P to position the second housing 70 relative to the first housing 60 while bringing the first housing 60 and the second housing 70 closer to each other in the axial direction. At this time, the worker or the like places the first housing 60 vertically downward, and brings the second housing 70 relatively closer to the first housing 60 from above in the vertical direction. This prevents the washer 32 surrounding the fixed shaft 30 from falling off vertically downward.

[0083] The jig P has a base portion Pa and a pin portion Pb. The base portion Pa is cylindrical and centered on the central axis J. The pin portion Pb extends axially from the base portion Pa. The tip of the pin portion Pb is conical. The base portion Pa is fitted into the first suction port portion 74a. This allows the jig P to be positioned radially with respect to the second housing 70. The pin portion Pb is passed axially through the through hole 75c and inserted into the impeller portion 40 from the second suction port portion 44. The tip of the pin portion Pb is fitted into a recess 33 provided at the axial end of the fixed shaft 30. More specifically, the tip of the pin portion Pb is fitted into the tapered portion 33a of the recess 33. This allows the jig P to be positioned radially with respect to the fixed shaft 30. Therefore, the fixed shaft 30 and the second housing 70 can be positioned radially relative to each other via the jig P, and the second housing 70 can be positioned with high axial precision relative to the fixed shaft 30. In this state, the worker 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 through hole 75c is provided in the rotor support portion 75. This allows for an assembly method in which the first housing 60 and the second housing 70 are brought closer to each other while the pin portion Pb of the jig P is passed through the through hole 75c and the tip of the pin portion Pb is fitted into the recess 33 of the fixed shaft 30 for positioning. This allows the second housing 70 to be fixed to the first housing 60 via the jig P with high axial accuracy relative to the fixed shaft 30. The fixed shaft 30 rotatably supports the rotor 10, and the impeller portion 40 is connected to the axial end of the rotor 10. Therefore, the rotor 10 and the impeller portion 40 are positioned radially relative to the fixed shaft 30. The second housing 70 is provided with a flow passage portion 76 extending circumferentially radially outward of the impeller portion 40. Therefore, since the second housing 70 can be positioned with high axial accuracy relative to the fixed shaft 30, the impeller portion 40 and the flow passage portion 76 can be positioned with high axial accuracy relative to each other. Therefore, the water W can easily flow from the impeller portion 40 into the flow path portion 76, and the efficiency of the pump 100 can be improved.

[0085] Second Embodiment As shown in FIG. 11 , in the pump 200 of this embodiment, the fixed shaft 230 is passed through a through-hole 75c provided in the rotor support portion 75. The lower end of the fixed shaft 230 is located below the through-hole 75c. This makes it easy to increase the area of ​​the portion of the fixed shaft 230 that is exposed inside the impeller portion 40. This increases the area of ​​the fixed shaft 230 that comes into contact with the water W. This makes it easier for the heat of the fixed shaft 230 to be released into the water W. This further improves the heat dissipation performance of the fixed shaft 230. The rest of the configuration of the fixed shaft 230 is the same as the rest of the configuration of the fixed shaft 30 in the first embodiment. The rest of the configuration of the pump 200 is the same as the rest of the configuration of the pump 100 in the first embodiment.

[0086] <Third embodiment> As shown in FIG. 12, in the pump 300 of this embodiment, the leg portion 375b of the rotor support portion 375 has a curved surface 375h facing the interior (inside) of the first suction port 74a. This reduces the resistance of the leg portion 375b to the water W flowing in from the first suction port 74a. This further reduces the obstruction of the flow of water W by the leg portion 375b, even when the leg portion 375b is provided. In this embodiment, the curved surface 375h is the lower surface of the first extension portion 375f. The curved surface 375h is a semicircular arc-shaped surface that is convex downward when viewed in the direction in which the first extension portion 375f extends. The curved surface 375h is positioned upward as it extends radially inward. The rest of the configuration of the leg portion 375b is similar to the rest of the configuration of the leg portion 75b in the first embodiment. Although not shown, in this embodiment, each of the multiple leg portions 375b has a curved surface 375h. Other configurations of the rotor support portion 375 are similar to other configurations of the rotor support portion 75 in the first embodiment. Other configurations of the pump 300 are similar to other configurations of the pump 100 in the first embodiment.

[0087] The present invention is not limited to the above-described embodiment, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The fixed shaft may be exposed in any structure as long as it is exposed in the second suction port of the impeller unit. For example, the rotor support unit may be composed only of multiple legs, thereby exposing a portion of the fixed shaft in the second suction port. In this case, the rotor is supported by the ends of the multiple legs on the other axial side (upper side). If a through-hole is provided in the rotor support unit that penetrates the rotor support unit in the axial direction, the fixed shaft does not have to be inserted into the through-hole. For example, the end of the fixed shaft on one axial side (lower side) may be located on the other axial side (upper side) of the through-hole. The portion of the fixed shaft exposed in the second suction port may not have a recess. The first suction port that opens into the interior of the impeller accommodating unit may be located in any position. A washer surrounding the fixed shaft may not be provided.

[0088] The use of the pump to which the present invention is applied is not particularly limited. The pump may be mounted on any type of equipment. For example, the pump may be mounted on a vehicle. The pump may be a pump that pumps any type of fluid. The pump may be an oil pump that pumps oil.

[0089] The present technology can be configured as follows. (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 housing having a rotor accommodating portion that accommodates the rotor therein; and a fixed shaft extending in the axial direction and rotatably supporting the rotor, wherein the housing has a rotor support portion that supports the rotor from one axial side, an impeller accommodating portion that accommodates the impeller portion therein and whose interior is connected to the interior of the rotor accommodating portion, and a first intake port portion that opens into the interior of the impeller accommodating portion, the impeller portion having a second intake port portion that opens to one axial side, and a portion of the fixed shaft being exposed to the second intake port portion. (2) The pump according to (1), wherein the rotor support portion has a through hole that passes through 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 one axial end of the fixed shaft is positioned within the through hole. (5) The pump according to (3), wherein the fixed shaft is passed through the through hole, and one axial end of the fixed shaft is located on one axial side of the through hole. (6) A pump described in any one of (2) to (5), wherein the rotor support portion has a support main body portion that supports the rotor and a plurality of legs that connect the support main body portion to the inner surface of the impeller accommodating portion, and the through hole is provided in the support main body portion. (7) The pump according to (6), wherein the leg portion has a curved surface facing the inside of the first intake port portion. (8) The pump according to any one of (1) to (7), wherein the second intake port portion is disposed on the other axial side of the first intake port portion. (9) The pump according to any one of (1) to (8), wherein the fixed shaft has a recess provided in a portion of the fixed shaft that is exposed to the second intake port portion. (10) The pump according to (9), wherein the recess is recessed from an end face on one axial side of the fixed shaft to the other axial side. (11) A pump described in 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 hooked circumferentially onto the fixed shaft.

[0090] The configurations and methods described in this specification can be combined as appropriate within the scope of not being mutually contradictory. [Explanation of symbols]

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

Claims

1. a rotor rotatable about a central axis; a stator that faces the rotor in a radial direction with a gap therebetween; an impeller portion connected to one axial side of the rotor; a housing having a rotor accommodating portion for accommodating the rotor therein; a fixed shaft extending in the axial direction and rotatably supporting the rotor; Equipped with The housing includes: a rotor support portion that supports the rotor from one axial side; an impeller accommodating portion that accommodates the impeller portion therein and whose interior is connected to the interior of the rotor accommodating portion; a first intake port portion that opens into the impeller accommodating portion; and the impeller portion has a second intake port portion that opens to one side in the axial direction, A pump, wherein a portion of the fixed shaft is exposed to the second intake port portion.

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

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

4. The pump according to claim 3 , wherein one axial end of the fixed shaft is located within the through hole.

5. The fixed shaft is passed through the through hole, The pump according to claim 3 , wherein one axial end of the fixed shaft is located on one axial side of the through hole.

6. The rotor support portion is a support body portion that supports the rotor; a plurality of legs connecting the support body and the inner surface of the impeller accommodating portion; and The pump according to claim 2 , wherein the through-hole is provided in the support body portion.

7. The leg portion has a curved surface facing the inside of the first intake port portion.

7. The pump of claim 6.

8. The pump according to claim 1 , wherein the second suction port portion is disposed on the other axial side of the first suction port portion.

9. The pump according to claim 1 , wherein the fixed shaft has a recess provided in a portion of the fixed shaft that is exposed to the second suction port portion.

10. The pump according to claim 9 , wherein the recess is recessed from an end face on one axial side of the fixed shaft toward the other axial side.

11. a washer surrounding the fixed shaft; The pump according to claim 1 , wherein the washer is provided between the rotor support portion and the rotor, and is hooked circumferentially around the fixed shaft.

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