Pump

Abstract

This pump comprises: a rotor that can rotate about a central axis; a stator that is positioned radially outward of the rotor and that surrounds the rotor; a pump unit that is connected to one side in the axial direction of the rotor; an accommodation member that accommodates the rotor therein; and a bus bar assembly that includes a bus bar which is electrically connected to a coil provided to the stator, and a bus bar holder which holds the bus bar. The accommodation member includes: a lid part that covers the rotor from the other side in the axial direction; a cylindrical part that is positioned between the rotor and the stator in the radial direction, and that opens to the one side in the axial direction; and a bottom part that spreads radially outward from the cylindrical part, and that covers the stator from the one side in the axial direction. The stator has a stator core positioned radially outward of the cylindrical part. The bus bar assembly has a ground connection member held by the bus bar holder, and is positioned on the other side in the axial direction of the lid part. The ground connection member contacts a stator core.

Description

pump

[0001] The present invention relates to a pump.

[0002] 2. Description of the Related Art An electric pump including a rotor, a stator, and a pump section is known (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2019-183766

[0004] The electric pump described above may include a plurality of components connected to the stator, such as bus bars for supplying power to the coils of the stator. In this case, the number of steps required to connect the plurality of components to the stator increases, which may reduce the ease of assembly of the electric pump.

[0005] In view of the above circumstances, one object of the present invention is to provide a pump having a structure that can improve assembly efficiency.

[0006] One aspect of the pump of the present invention includes a rotor rotatable about a central axis, a stator positioned radially outward of the rotor and surrounding the rotor, a pump section connected to one axial side of the rotor, a housing member that houses the rotor, bus bars electrically connected to coils provided on the stator, and a bus bar assembly having a bus bar holder that holds the bus bars. The housing member has a lid portion that covers the rotor from the other axial side, a cylindrical portion positioned radially between the rotor and the stator and opening to the one axial side, and a bottom portion that extends radially outward from the cylindrical portion and covers the stator from the one axial side. The stator has a stator core positioned radially outward of the cylindrical portion. The bus bar assembly has a ground connection member held by the bus bar holder and is positioned on the other axial side of the lid portion. The ground connection member contacts the stator core.

[0007] According to one aspect of the present invention, for example, the assembly of the pump can be improved.

[0008] FIG. 1 is a cross-sectional view of a pump according to an embodiment. FIG. 2 is a perspective view of a stator core and a housing member according to an embodiment. FIG. 3 is a perspective view of a stator, a housing member, and a bus bar assembly according to an embodiment. FIG. 4 is a top view of a portion of a stator, a portion of a housing member, and a portion of a bus bar assembly according to an embodiment. FIG. 5 is a top view of a portion of a stator and a portion of a housing member according to an embodiment. FIG. 6 is a cross-sectional view of a portion of a pump according to an embodiment. FIG. 7 is a perspective view of a portion of a housing member and a fixed shaft according to an embodiment. FIG. 8 is a perspective view of a portion of a housing member according to an embodiment. FIG. 9 is a cross-sectional view of another portion of a pump according to an embodiment. FIG. 10 is a cross-sectional view of yet another portion of a pump according to an embodiment. FIG. 11 is a perspective view of a bus bar assembly according to an embodiment. FIG. 12 is a cross-sectional view of a portion of an assembly procedure for a pump according to an embodiment.

[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 the “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 relationship of each part, and the actual positional relationship may be one other than the positional relationship indicated by these names.

[0011] The pump 100 of this embodiment shown in Fig. 1 is an electric pump. The pump 100 is, for example, a water pump that pumps water. As shown in Fig. 1, the pump 100 of this embodiment includes a rotor 10, a stator 20, a fixed shaft 30, a pump section 40, a housing 50, an accommodating member 70, and a bus bar assembly 80.

[0012] The rotor 10 is rotatable about a central axis J. The rotor 10 has a rotor core 11, a magnet 12, a resin part 13, and a guide member 15. The rotor core 11 is annular and surrounds the central axis J. The magnet 12 is fixed to a radially outer surface of the rotor core 11. A plurality of magnets 12 are provided at intervals in the circumferential direction.

[0013] The resin portion 13 has a generally cylindrical shape that surrounds the central axis J and extends in the axial direction. The rotor core 11 and a plurality of magnets 12 are embedded in the resin portion 13. The guide member 15 has a generally cylindrical shape that surrounds the central axis J and extends in the axial direction. The guide member 15 is located radially inside the resin portion 13. The outer peripheral surface of the guide member 15 is fixed to the inner peripheral surface of the resin portion 13. The guide member 15 is made of, for example, resin.

[0014] The stator 20 is located radially outside the rotor 10. The stator 20 surrounds the rotor 10. The stator 20 includes a stator core 21, an insulator 22, and a plurality of coils 23. 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 located radially outside a first cylindrical portion 71b, which will be described later. The stator core 21 is formed, for example, by stacking a plurality of plate members in the axial direction. The plurality of plate members that form the stator core 21 are, for example, electromagnetic steel plates. As shown in FIG. 2 , the stator core 21 includes a core back 24 and a plurality of teeth 25.

[0015] The core back 24 is annular and surrounds the central axis J. In this embodiment, the core back 24 is substantially circular and centered on the central axis J. The core back 24 surrounds a first cylindrical portion 71b, which will be described later. The core back 24 has a fitting recess 24a extending in the axial direction. The fitting recess 24a is recessed from the radially outer side to the radially inner side of the core back 24. The fitting recess 24a is open on both axial sides. When viewed in the axial direction, the interior of the fitting recess 24a has a substantially triangular shape that convex radially inward. The fitting recess 24a is provided on the radially outer surface of the core back 24 in a circumferential portion where the radially outer ends of the teeth 25 are connected. In this embodiment, two fitting recesses 24a are provided spaced apart in the circumferential direction.

[0016] The teeth 25 extend radially inward from the core back 24. The teeth 25 are spaced apart in the circumferential direction. In this embodiment, the teeth 25 are arranged at equal intervals around the circumference. In this embodiment, nine teeth 25 are provided. Each tooth 25 has a tooth main body 25a and an umbrella portion 25b. The tooth main body 25a extends radially inward from the radially inner surface of the core back 24. The umbrella portion 25b is connected to the radially inner end of the tooth main body 25a. The umbrella portion 25b protrudes on both circumferential sides beyond the tooth main body 25a. When viewed in the axial direction, the radially inner surface of the umbrella portion 25b is arc-shaped with the central axis J as its center. The radially inner surface of the umbrella portion 25b is the radially inner surface of the tooth 25.

[0017] The stator core 21 has a hole 26 recessed downward. In the present embodiment, the hole 26 is provided in the core back 24. Therefore, the magnetic flux flowing through the stator core 21 is less likely to be obstructed by the hole 26 than when the hole 26 is provided in the tooth 25. The hole 26 is provided in a circumferential portion of the core back 24 where the radially outer end of one of the teeth 25 is connected. In the present embodiment, the hole 26 has a portion that is provided at the same circumferential position as the circumferential center of one of the teeth 25. Therefore, the hole 26 can be provided in a portion of the core back 24 where magnetic flux is relatively difficult to flow. This makes it less likely that the magnetic flux flowing through the stator core 21 will be obstructed by the hole 26. In the present embodiment, the circumferential center position of the hole 26 is the same as the circumferential center position of one of the teeth 25 that is connected to the circumferential portion of the core back 24 where the hole 26 is provided. When viewed in the axial direction, the hole 26 has a rectangular shape that is elongated in a direction perpendicular to the radial direction. As shown in FIG. 1, in this embodiment, the hole 26 is a hole that passes through the stator core 21 in the axial direction.

[0018] The insulator 22 is attached to the stator core 21. The insulator 22 has a plurality of tooth cover portions 22e. The plurality of tooth cover portions 22e are attached to the plurality of teeth 25, respectively. Each tooth cover portion 22e covers each tooth 25 from both axial and circumferential sides. The insulator 22 has a first outer protrusion 22a, a second outer protrusion 22b, a first inner protrusion 22c, and a second inner protrusion 22d.

[0019] The first outer protrusion 22a and the second outer protrusion 22b are located radially outward of the tooth cover portion 22e. The first outer protrusion 22a protrudes upwardly beyond the tooth cover portion 22e. The second outer protrusion 22b protrudes downwardly beyond the tooth cover portion 22e. The first outer protrusion 22a is located above the stator core 21. The first outer protrusion 22a is located above the core back 24. In this embodiment, the second outer protrusion 22b corresponds to a protrusion that protrudes downwardly beyond the stator core 21, i.e., to one axial side. The second outer protrusion 22b is located below the core back 24.

[0020] As shown in Figures 3, 4, and 5, multiple first outer protrusions 22a are provided at intervals in the circumferential direction. Although not shown, multiple second outer protrusions 22b are also provided at intervals in the circumferential direction, similar to the first outer protrusions 22a. As shown in Figure 1, the multiple first outer protrusions 22a and the multiple second outer protrusions 22b are connected to the radially outer ends of the multiple tooth cover portions 22e. As shown in Figure 5, one first outer protrusion 22f of the multiple first outer protrusions 22a has a groove 22g recessed radially inward from the radially outer surface of the first outer protrusion 22f. The groove 22g extends axially and opens on both axial sides. The interior of the groove 22g overlaps the entire hole 26 when viewed axially.

[0021] The first inner protrusions 22c are provided in plurality at intervals in the circumferential direction. As shown in FIG. 1 , the first inner protrusions 22c are connected to the radially inner ends of the tooth cover portions 22e, respectively. The first inner protrusions 22c protrude upward beyond the tooth cover portions 22e. The upper ends of the first inner protrusions 22c are located lower than the upper ends of the first outer protrusions 22a. Although not shown, the second inner protrusions 22d are also provided in plurality at intervals in the circumferential direction. The second inner protrusions 22d are connected to the radially inner ends of the tooth cover portions 22e, respectively. The second inner protrusions 22d protrude downward beyond the tooth cover portions 22e. The lower ends of the second inner protrusions 22d are located higher than the lower ends of the second outer protrusions 22b.

[0022] The plurality of coils 23 are attached to the stator core 21 via insulators 22. More specifically, the plurality of coils 23 are attached to the plurality of teeth 25 via tooth cover portions 22e. Each coil 23 is configured by winding a conductor around the tooth cover portion 22e. Each coil 23 has a portion located radially between the first outer protrusion 22a and the first inner protrusion 22c, and a portion located radially between the second outer protrusion 22b and the second inner protrusion 22d.

[0023] 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 the central axis J. The fixed shaft 30 is located radially inside the guide member 15 of the rotor 10. The fixed shaft 30 passes through the radially inside of the guide member 15 in the axial direction. The fixed shaft 30 protrudes beyond the guide member 15 on both sides in the axial direction. The fixed shaft 30 is clearance-fitted into the radially inside of the guide member 15. The fixed shaft 30 supports the inner circumferential surface of the guide member 15, thereby rotatably supporting the rotor 10.

[0024] The upper end of the fixed shaft 30 is embedded and held in a lid portion 71a (described later) of the housing member 70. The fixed shaft 30 extends downward from the lid portion 71a. The lower end of the fixed shaft 30 is located below a rotor housing portion 71 (described later). As shown in FIG. 6 , an annular groove 31a recessed radially inward is provided on the outer peripheral surface of the portion of the fixed shaft 30 embedded in the lid portion 71a. The annular groove 31a has a circular ring shape surrounding the central axis J. The annular groove 31a is located below the upper end face of the fixed shaft 30. A portion of the resin constituting the lid portion 71a enters the annular groove 31a, thereby preventing the fixed shaft 30 from slipping out of the lid portion 71a in the axial direction. A plurality of axial grooves 32a extending axially and aligned circumferentially are provided on the outer peripheral surface of the upper end portion 32 of the fixed shaft 30 above the annular groove 31a. A portion of the resin constituting the lid portion 71a enters the multiple axial grooves 32a, thereby suppressing rotation of the fixed shaft 30 relative to the lid portion 71a around the central axis J. The upper end portion 32 is provided with a support hole 33 recessed downward from the upper end face of the upper end portion 32.

[0025] The fixed shaft 30 has an axially symmetrical shape. As shown in Fig. 7, an annular groove 31b is also provided in the lower portion of the fixed shaft 30. The annular groove 31b has a circular ring shape surrounding the central axis J. The annular groove 31b is located above the lower end face of the fixed shaft 30. A plurality of axial grooves 34a extending in the axial direction and aligned in the circumferential direction are provided in the outer peripheral surface of the lower end portion 34 of the fixed shaft 30 below the annular groove 31b.

[0026] As shown in FIG. 1 , the pump section 40 is connected to the lower side of the rotor 10. In this embodiment, the pump section 40 is an impeller. When the rotor 10 rotates about the central axis J, the pump section 40 rotates about the central axis J. The pump section 40 is made of resin. The pump section 40 has an impeller main body 41, a shroud 42, and a plurality of blades 43. In this embodiment, the impeller main body 41 is connected to the lower end of the resin section 13. The resin section 13 and the impeller main body 41 are part of the same single member. The impeller main body 41 has a substantially annular shape centered on the central axis J. The outer diameter of the impeller main body 41 is larger than the outer diameter of the lower end of the resin section 13.

[0027] The shroud portion 42 is separate from the impeller main body portion 41. The shroud portion 42 is arranged below the impeller main body portion 41 with a gap therebetween. The shroud portion 42 is annular and centered on the central axis J. The plurality of blade portions 43 are located axially between the impeller main body portion 41 and the shroud portion 42. The plurality of blade portions 43 are arranged with a gap therebetween in the circumferential direction. 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 contact the impeller main body portion 41.

[0028] The housing 50 accommodates the rotor 10, the stator 20, the fixed shaft 30, the pump unit 40, the housing member 70, and the bus bar assembly 80. The housing 50 has a first housing 51 and a second housing 52. The first housing 51 and the second housing 52 are separate from each other. The first housing 51 is located above the second housing 52. The first housing 51 and the second housing 52 are fixed to each other. In this embodiment, the first housing 51 and the second housing 52 are made of resin. However, the first housing 51 and the second housing 52 may also be made of metal.

[0029] The first housing 51 is a cylindrical member that opens downward. More specifically, the first housing 51 has a substantially cylindrical shape centered on the central axis J. The first housing 51 has a top wall portion 51a, a first peripheral wall portion 51b, a first flange portion 51c, and a connector portion 51d. In other words, the housing 50 has the top wall portion 51a, the first peripheral wall portion 51b, the first flange portion 51c, and the connector portion 51d.

[0030] The top wall portion 51a is located above the stator 20 and the busbar assembly 80. The top wall portion 51a covers the stator 20 and the busbar assembly 80 from above. The first circumferential wall portion 51b extends downward from the radial outer edge of the top wall portion 51a. The first circumferential wall portion 51b has a cylindrical shape that opens downward. More specifically, the first circumferential wall portion 51b has a substantially cylindrical shape that opens downward and is centered on the central axis J. The first circumferential wall portion 51b surrounds the upper portion of the stator 20 and the busbar assembly 80 from the radial outside. In this embodiment, the first circumferential wall portion 51b corresponds to a cylindrical circumferential wall portion that surrounds the stator core 21 from the radial outside. The radial inner surface of the first circumferential wall portion 51b is spaced radially outward from the radial outer surface of the core back 24. In this embodiment, a lower portion of the radially inner surface of the first peripheral wall portion 51b faces the radially outer surface of the core back 24 with a radial gap therebetween. The first flange portion 51c protrudes radially outward from the lower end of the first peripheral wall portion 51b. The first flange portion 51c is annular and surrounds the central axis J. The connector portion 51d protrudes upward from the top wall portion 51a. The connector portion 51d is cylindrical and opens upward. The central axis J passes through the connector portion 51d.

[0031] The second housing 52 is a tubular member that opens upward. More specifically, the second housing 52 has a generally cylindrical shape centered on the central axis J. The second housing 52 has a bottom wall portion 52a, a second circumferential wall portion 52b, and a second flange portion 52c. The bottom wall portion 52a is annular and surrounds the central axis J. The bottom wall portion 52a is located below the pump portion 40. The bottom wall portion 52a covers the pump portion 40 from below. The radially outer end of the bottom wall portion 52a is located radially outer than the pump portion 40. The second circumferential wall portion 52b extends upward from the radial outer edge of the bottom wall portion 52a. The second circumferential wall portion 52b has a generally cylindrical shape that opens upward. The second circumferential wall portion 52b surrounds the lower portion of the stator 20 and the pump portion 40 from the radially outer side. The second flange portion 52c protrudes radially outward from the upper end of the second peripheral wall portion 52b and has an annular shape surrounding the central axis J. A third flange portion 74 (described later) is sandwiched between the second flange portion 52c and the first flange portion 51c in the axial direction.

[0032] The second housing 52 has an inlet port 52d and a flow path 52e. The inlet port 52d protrudes downward from the radially inner edge of the bottom wall 52a. In this embodiment, the inlet port 52d is substantially cylindrical and centered on the central axis J. The inlet port 52d opens downward. The flow path 52e is located radially outside the pump unit 40. The flow path 52e is provided radially between the pump unit 40 and the second peripheral wall 52b. Although not shown, the flow path 52e extends in the circumferential direction. A fluid that flows in from the inlet port 52d flows through the flow path 52e. In this embodiment, the fluid is water. The fluid that flows into the flow path 52e flows circumferentially within the flow path 52e and is discharged from a discharge port (not shown) to the outside of the pump 100.

[0033] The second housing 52 has a rotor support portion 53 that supports the rotor 10 from below. The rotor support portion 53 has a support main body portion 53a and multiple leg portions 53b. The support main body portion 53a supports the rotor 10 from below via a washer 53c. The fixed shaft 30 is passed axially through the inside of the washer 53c. The washer 53c contacts the upper end of the support main body portion 53a and the lower end of the guide member 15. The multiple leg portions 53b extend upward from the inner circumferential surface of the suction port portion 52d. The upper ends of the multiple leg portions 53b are connected to the support main body portion 53a.

[0034] The accommodating member 70 accommodates the rotor 10 therein. In this embodiment, the accommodating member 70 is made of resin. The accommodating member 70 is fixed to the housing 50. The accommodating member 70 has a rotor accommodating portion 71, a bottom portion 72, a second cylindrical portion 73, and a third flange portion 74. The rotor accommodating portion 71 is a cylindrical portion that accommodates the rotor 10 therein. The rotor accommodating portion 71 surrounds the central axis J and opens downward. As shown in FIGS. 7 and 8 , in this embodiment, the rotor accommodating portion 71 has a substantially cylindrical shape that is centered on the central axis J and opens downward. The rotor accommodating portion 71 has a lid portion 71 a and a first cylindrical portion 71 b. That is, the accommodating member 70 has the lid portion 71 a and the first cylindrical portion 71 b.

[0035] The lid portion 71a is the uppermost wall portion of the walls that make up the rotor accommodating portion 71. In this embodiment, the lid portion 71a has a circular shape centered on the central axis J when viewed in the axial direction. As shown in FIG. 6 , the lid portion 71a covers the rotor 10 from above. The upper end of the fixed shaft 30 is embedded in the lid portion 71a. This allows the lid portion 71a to hold the upper end of the fixed shaft 30. The lid portion 71a has a lid main body portion 71e and a shaft holding portion 71c.

[0036] The lid main body 71e has a generally circular plate shape centered on the central axis J. The lid main body 71e is located above the rotor 10. The shaft holding portion 71c protrudes downward from the lower surface of the lid main body 71e. The shaft holding portion 71c has a generally cylindrical shape centered on the central axis J. The upper end of the fixed shaft 30 is embedded and held in the shaft holding portion 71c. As shown in FIG. 7 , a sixth rib 71d is provided on the lower surface of the lid main body 71e. The sixth rib 71d extends radially. The sixth rib 71d connects the radially outer surface of the shaft holding portion 71c and the radially inner surface of the first cylindrical portion 71b. A plurality of sixth ribs 71d are provided at intervals in the circumferential direction. In this embodiment, the plurality of sixth ribs 71d are arranged at equal intervals around the circumference.

[0037] As shown in FIG. 8 , in this embodiment, the lid portion 71a has a positioning portion 75. That is, in this embodiment, the accommodating member 70 has the positioning portion 75, and the positioning portion 75 is provided on the lid portion 71a. The positioning portion 75 is provided on the upper surface of the lid main body portion 71e. The positioning portion 75 is a convex portion that protrudes in the axial direction. More specifically, the positioning portion 75 is a convex portion that protrudes upward from the upper surface of the lid main body portion 71e. In this embodiment, the positioning portion 75 has a circular shape centered on the central axis J when viewed in the axial direction. The positioning portion 75 has a substantially cylindrical shape centered on the central axis J. A recessed portion 75a is provided on the axial end surface of the positioning portion 75. The recessed portion 75a is recessed downward from the upper end surface of the positioning portion 75. The recessed portion 75a has a circular shape centered on the central axis J when viewed in the axial direction.

[0038] As shown in FIG. 6 , the positioning portion 75 overlaps with the shaft holding portion 71c when viewed in the axial direction. The upper end face of the fixed shaft 30 is embedded within the positioning portion 75. Because a portion of the fixed shaft 30 can be held using the positioning portion 75 that protrudes in the axial direction, it is easy to lengthen the portion of the fixed shaft 30 that is held by the lid portion 71a in the axial direction. This makes it easy to stably hold the fixed shaft 30 on the lid portion 71a. Furthermore, compared to when the upper end face of the fixed shaft 30 is located below the positioning portion 75, the axial position of the fixed shaft 30 can be positioned higher. This makes it easy to reduce the axial dimension of the portion of the fixed shaft 30 that protrudes downward from the lid portion 71a, preventing the pump 100 from becoming larger in the axial direction.

[0039] As shown in FIG. 1 , the first cylindrical portion 71b extends downward from the radial outer edge of the cover portion 71a. The first cylindrical portion 71b is cylindrical and opens downward. In this embodiment, the first cylindrical portion 71b is centered on the central axis J and has a substantially cylindrical shape that opens downward. The first cylindrical portion 71b is located radially between the rotor 10 and the stator 20. The first cylindrical portion 71b is axially passed through the radially inner side of the stator core 21. The rotor 10 is located radially inside the first cylindrical portion 71b.

[0040] The lower end of the first cylindrical portion 71b is connected to the radial inner edge of the bottom portion 72. The first cylindrical portion 71b connects the bottom portion 72 and the lid portion 71a. As shown in FIG. 8 , the radially outer surface of the first cylindrical portion 71b at the portion where it connects to the radially outer edge of the lid portion 71a is a curved surface that is positioned radially inward as it extends upward. In this embodiment, the accommodating member 70 is made of resin, and therefore the first cylindrical portion 71b is made of a non-magnetic material. Therefore, the magnetic flux flowing between the rotor 10 and the stator 20 is not obstructed by the first cylindrical portion 71b. In this embodiment, the entire accommodating member 70 is made of a non-magnetic material.

[0041] A first rib 76 extending in the axial direction is provided on the radially outer surface of the first cylindrical portion 71b. The first rib 76 protrudes radially outward from the radially outer surface of the first cylindrical portion 71b. As shown in FIG. 9 , the first rib 76 contacts the radially inner surfaces of the teeth 25. Therefore, the first rib 76 radially positions the stator core 21 relative to the accommodating member 70. This allows the stator 20 to be positioned with high axial precision relative to the fixed shaft 30 held by the lid portion 71a of the accommodating member 70. Therefore, the stator 20 can be positioned with high precision relative to the rotor 10 without embedding and fixing the stator 20 in the accommodating member 70 by insert molding or the like. This allows the stator 20 to be positioned with high precision while suppressing an increase in the manufacturing process of the pump 100.

[0042] Furthermore, the provision of the first rib 76 improves the rigidity of the first cylindrical portion 71b. Therefore, even when the stator core 21 is supported by the first cylindrical portion 71b, deformation of the first cylindrical portion 71b can be suppressed, and the stator core 21 can be stably supported by the first cylindrical portion 71b. The first cylindrical portion 71b is a substantially cylindrical portion that does not include the first rib 76, a second rib 77 (described later), or a fourth rib 79a (described later). The wall portion that constitutes the first cylindrical portion 71b is a substantially cylindrical wall portion that does not include the first rib 76, the second rib 77, or the fourth rib 79a. The radial thickness of the wall portion that constitutes the first cylindrical portion 71b is equal to the radial distance between the radially inner surface of the first cylindrical portion 71b and the radially outer surface of the first cylindrical portion 71b. The radially outer surface of the first cylindrical portion 71b is a surface that connects the radially inner end of the first rib 76, the radially inner end of the second rib 77, and the radially inner end of the fourth rib 79a, and does not include the radially outer surface of the first rib 76, the radially outer surface of the second rib 77, and the radially outer surface of the fourth rib 79a.

[0043] As shown in FIG. 8 , the upper end of the first rib 76 is located lower than the upper end of the first cylindrical portion 71b. Therefore, when inserting the first cylindrical portion 71b radially inside the stator core 21, a portion of the first cylindrical portion 71b located above the first rib 76 can be inserted radially inside the stator core 21 before the teeth 25 come into contact with the first rib 76. This allows the teeth 25 and the first rib 76 to come into radial contact with each other while the stator core 21 is positioned to a certain extent relative to the accommodating member 70 by the portion of the first cylindrical portion 71b located above the first rib 76. Therefore, the stator core 21 can be easily assembled to the accommodating member 70 while the teeth 25 are in contact with the first rib 76. The lower end of the first rib 76 is located higher than the lower end of the first cylindrical portion 71b.

[0044] The upper end of the first rib 76 is provided with an inclined portion 76a whose radial dimension decreases toward the upper side. Therefore, when assembling the stator core 21 to the accommodating member 70, the radial position of the teeth 25 can be aligned along the inclined portion 76a. This makes it easier to assemble the stator core 21 to the accommodating member 70 while the radial inner surfaces of the teeth 25 are in contact with the first rib 76. The radial outer surfaces of the inclined portions 76a are inclined surfaces that are positioned radially inward toward the upper side. As shown in FIG. 9 , the axial dimension of the first rib 76 is larger than the axial dimension of the teeth 25. The first rib 76 protrudes on both axial sides beyond the teeth 25. Portions of the radial outer surfaces of the first ribs 76 that are located below the inclined portion 76a contact the radial inner surfaces of the teeth 25.

[0045] As shown in FIG. 8 , in this embodiment, a plurality of first ribs 76 are provided at intervals in the circumferential direction. The plurality of first ribs 76 are arranged at equal intervals around the circumference. As shown in FIG. 2 , the plurality of first ribs 76 contact the radially inner surfaces of the plurality of teeth 25. Each of the first ribs 76 contacts the circumferential center of the radially inner surface of each tooth 25. The plurality of first ribs 76 arranged in an annular shape around the circumference are, for example, press-fitted into the radially inner side of the plurality of teeth 25 arranged in an annular shape around the circumference. This allows the rotor accommodating portion 71 to be press-fitted into the radially inner side of the stator core 21.

[0046] A second rib 77 extending in the axial direction is provided on the radially outer surface of the first cylindrical portion 71b. The second rib 77 protrudes radially outward from the radially outer surface of the first cylindrical portion 71b. The second rib 77 is provided between circumferentially adjacent teeth 25. Therefore, the second rib 77 can further improve the rigidity of the first cylindrical portion 71b while avoiding contact between the second rib 77 and the teeth 25. This allows the stator 20 to be more stably supported by the first cylindrical portion 71b. The second rib 77 is provided between the umbrella portions 25b of circumferentially adjacent teeth 25. The second rib 77 is provided circumferentially spaced apart from each of the circumferentially adjacent umbrella portions 25b. As shown in FIG. 8 , the upper end of the second rib 77 is located above the upper end of the first rib 76. This makes it easy to increase the size of the second rib 77 in the axial direction, and makes it easy to further improve the rigidity of the first cylindrical portion 71 b by the second rib 77. In the present embodiment, the upper end of the second rib 77 is provided on the radially outer surface of the upper end of the first cylindrical portion 71 b.

[0047] The lower end of the second rib 77 is located lower than the lower end of the first rib 76. The lower end of the second rib 77 is provided on the radially outer surface of the lower end of the first cylindrical portion 71b. The axial dimension of the second rib 77 is larger than the axial dimension of the first rib 76. The second rib 77 protrudes axially on both sides beyond the first rib 76. The radial dimension of the second rib 77 is larger than the radial dimension of the first rib 76. The radially outer end of the second rib 77 is located radially outward than the radially outer end of the first rib 76. The circumferential dimension of the second rib 77 is larger than the circumferential dimension of the first rib 76.

[0048] In the present embodiment, the second ribs 77 are provided in plurality at intervals in the circumferential direction. That is, in the present embodiment, a plurality of first ribs 76 and a plurality of second ribs 77 are provided. In the present embodiment, the number of first ribs 76 and the number of second ribs 77 are equal to the number of teeth 25. The second ribs 77 are arranged at equal intervals around the circumference. The first ribs 76 and the second ribs 77 are alternately arranged at intervals in the circumferential direction. Therefore, the first ribs 76 and the second ribs 77 can more suitably improve the rigidity of the first cylindrical portion 71b, and the first ribs 76 can more stably support the stator core 21 relative to the first cylindrical portion 71b. Each first rib 76 is located in the circumferential center between circumferentially adjacent second ribs 77.

[0049] A fourth rib 79a extending in the circumferential direction is provided on the radially outer surface of the first cylindrical portion 71b. The fourth rib 79a protrudes radially outward from the radially outer surface of the first cylindrical portion 71b. The fourth rib 79a is provided on the radially outer surface of a portion of the first cylindrical portion 71b located below the first rib 76. In this embodiment, the fourth rib 79a is provided on the radially outer surface of the lower end of the first cylindrical portion 71b. The lower end of the first rib 76 is connected to the circumferential center of the fourth rib 79a. The fourth rib 79a is located between two circumferentially adjacent second ribs 77. The fourth rib 79a connects two circumferentially adjacent second ribs 77. The fourth rib 79a can more suitably improve the rigidity of the first cylindrical portion 71b. The fourth rib 79a is provided between each pair of two circumferentially adjacent second ribs 77.

[0050] The bottom 72 extends radially outward from the first cylindrical portion 71b. In this embodiment, the bottom 72 extends radially outward from the lower end of the first cylindrical portion 71b. The bottom 72 has an annular shape surrounding the central axis J. In this embodiment, the bottom 72 has a substantially circular annular shape centered on the central axis J. As shown in FIG. 1 , the bottom 72 covers the stator 20 from below. As shown in FIG. 8 , a third rib 78 extending radially is provided on the upper surface of the bottom 72. Therefore, the third rib 78 can improve the rigidity of the bottom 72. The radially inner end of the third rib 78 is connected to the lower end of the second rib 77. Therefore, the second rib 77 can be connected to the bottom 72 via the third rib 78. As a result, the rigidity of the first cylindrical portion 71b, on which the second rib 77 is provided, can be further improved via the second rib 77, the third rib 78, and the bottom 72. The third rib 78 protrudes upward from the upper surface of the bottom portion 72. In this embodiment, multiple third ribs 78 are provided at intervals in the circumferential direction. The radially inner ends of the multiple third ribs 78 are connected to the lower ends of the multiple second ribs 77, respectively. The radially outer ends of the third ribs 78 are connected to the radially inner surface of the second cylindrical portion 73. The number of third ribs 78 is the same as the number of second ribs 77.

[0051] A fifth rib 79b extending radially is provided on the upper surface of the bottom portion 72. The fifth rib 79b protrudes upward from the upper surface of the bottom portion 72. The bottom portion 72 does not include the third rib 78 or the fifth rib 79b. The upper surface of the bottom portion 72 is a surface where the lower ends of the third rib 78 and the lower ends of the fifth rib 79b are connected, but does not include the upper surfaces of the third rib 78 and the fifth rib 79b. The fifth rib 79b is located between two adjacent third ribs 78 in the circumferential direction. The fifth rib 79b is provided between each pair of adjacent third ribs 78 in the circumferential direction. The radially inner end of the fifth rib 79b is connected to the fourth rib 79a. The radially inner end of the fifth rib 79b is connected to the circumferential center of the fourth rib 79a. The radially outer end of the fifth rib 79b is provided radially inward and away from the second cylindrical portion 73. The upper surface of the fifth rib 79b is an inclined surface that slopes downward as it extends radially outward.

[0052] A groove 72a extending in the circumferential direction is provided on the upper surface of the bottom portion 72. In this embodiment, the groove 72a is provided on the radially outer edge of the upper surface of the bottom portion 72. A plurality of grooves 72a are provided at intervals in the circumferential direction. The plurality of grooves 72a are respectively provided between adjacent third ribs 78 in the circumferential direction. Each groove 72a extends from one adjacent third rib 78 to the other. Both circumferential ends of each groove 72a are closed by the third rib 78. As shown in FIG. 10 , the groove 72a is provided separately below the second outer protrusion 22b. In this embodiment, the groove 72a is provided in a portion of the bottom portion 72 that faces the second outer protrusion 22b in the axial direction. The radially outer edge of the groove 72a is located radially outward of the radially outer surface of the second outer protrusion 22b. The radially inner edge of the groove 72a is located radially outward of the radially inner surface of the second outer protrusion 22b.

[0053] The second cylindrical portion 73 has a cylindrical shape that protrudes upward from the bottom portion 72. In this embodiment, the second cylindrical portion 73 protrudes upward from the radial outer edge of the bottom portion 72. The second cylindrical portion 73 opens upward. In this embodiment, the second cylindrical portion 73 has a substantially cylindrical shape centered on the central axis J. The second cylindrical portion 73 has a lower cylindrical portion 73a and an upper cylindrical portion 73b. The upper cylindrical portion 73b is connected to the upper side of the lower cylindrical portion 73a. The inner diameter of the upper cylindrical portion 73b is larger than the inner diameter of the lower cylindrical portion 73a. A radially inner surface 73f of the upper cylindrical portion 73b is located radially outward from a radially inner surface 73e of the lower cylindrical portion 73a. The radially inner surface 73f of the upper cylindrical portion 73b is located radially inward from a radially inner surface of the first peripheral wall portion 51b.

[0054] The radially inner surface of the second cylindrical portion 73 is provided with a stepped portion 73c having an upwardly facing stepped surface 73d. The stepped surface 73d connects the upper end of the radially inner surface 73e of the lower cylindrical portion 73a to the lower end of the radially inner surface 73f of the upper cylindrical portion 73b. The stepped surface 73d is a flat surface perpendicular to the axial direction. The lower end surface of the radially outer edge of the core back 24 contacts the stepped surface 73d. This positions the stator 20 in the axial direction relative to the accommodating member 70. As shown in FIG. 8 , the stepped surface 73d is substantially annular and centered on the central axis J.

[0055] A mating protrusion 73g is provided on a radially inner surface 73f of the upper cylindrical portion 73b. The mating protrusion 73g protrudes radially inward from the radially inner surface 73f. When viewed in the axial direction, the mating protrusion 73g has a generally triangular shape that protrudes radially inward. A lower end of the mating protrusion 73g connects to the stepped surface 73d. Two mating protrusions 73g are provided, spaced apart in the circumferential direction. As shown in FIG. 2 , each mating protrusion 73g is fitted into a corresponding mating recess 24a. This prevents the stator core 21 from rotating relative to the accommodating member 70 around the central axis J.

[0056] As shown in FIG. 10 , a lower portion of the stator 20 is located radially inside the second cylindrical portion 73. A portion of the insulator 22 located below the stator core 21 and a portion of the coil 23 located below the stator core 21 are located radially inside the lower cylindrical portion 73a. The second outer protrusion 22b is located radially inside the lower cylindrical portion 73a, i.e., radially inside the second cylindrical portion 73. A gap G1 is provided radially between the radial outer surface of the second outer protrusion 22b and the radial inner surface of the second cylindrical portion 73. The gap G1 is provided radially between the radial inner surface 73e of the lower cylindrical portion 73a and the radial outer surface of the second outer protrusion 22b. The upper end of the gap G1 is connected to the lower end of the hole 26. The entire radial outer surface of the second outer protrusion 22b is located radially inwardly away from the radial inner surface 73e of the lower cylindrical portion 73a.

[0057] A portion of the lower portion of the stator core 21 is located radially inside the upper cylindrical portion 73b. A gap G2 is provided radially between the radially inner surface 73f of the upper cylindrical portion 73b and the radially outer surface of the stator core 21, i.e., the radially outer surface of the core back 24. The radial dimension of the gap G2 is larger than the radial dimension of the gap G1. The entire radially inner surface 73f of the upper cylindrical portion 73b is provided radially outwardly away from the radially outer surface of the core back 24.

[0058] As shown in FIG. 1 , the third flange portion 74 extends radially outward from the upper end of the second cylindrical portion 73. The third flange portion 74 is annular and surrounds the central axis J. More specifically, the third flange portion 74 is substantially annular and centered on the central axis J. The third flange portion 74 is located axially between the first flange portion 51c and the second flange portion 52c. The third flange portion 74 contacts the first flange portion 51c and the second flange portion 52c. A seal member 92 seals the gap between the first flange portion 51c and the third flange portion 74. The seal member 92 is annular and surrounds the central axis J. The seal member 92 is, for example, an O-ring.

[0059] As shown in FIG. 2 , a fixing portion 74a protruding radially outward is provided on the radial outer edge of the third flange portion 74. A plurality of fixing portions 74a are provided at intervals in the circumferential direction. In this embodiment, four fixing portions 74a are provided. Each fixing portion 74a is provided with a hole 74b that penetrates the fixing portion 74a in the axial direction. Although not shown, a screw member that penetrates a fixing portion provided on the second housing 52 in the axial direction and is fastened to a fixing portion provided on the first housing 51 is passed through the hole 74b of each fixing portion 74a. As a result, the first housing 51, the second housing 52, and the accommodating member 70 are fastened together and fixed to each other by the plurality of screw members that pass through the plurality of holes 74b.

[0060] As shown in FIG. 10 , in this embodiment, the stator 20 is fixed to the accommodating member 70 with an adhesive 90. More specifically, the insulator 22 is fixed to the accommodating member 70 with the adhesive 90. Therefore, compared to when the stator 20 is directly fixed to the housing 50, vibrations generated in the stator 20 can be more effectively prevented from being transmitted to the housing 50. This can suppress vibration of the housing 50. In this embodiment, as described above, the radially inner surface of the first circumferential wall portion 51b is spaced radially outward from the radially outer surface of the core back 24. This can suppress vibrations generated in the stator 20 from being directly transmitted from the core back 24 to the first circumferential wall portion 51b. This can further suppress vibration of the housing 50.

[0061] Furthermore, because the stator 20 can be fixed to the accommodating member 70 using the adhesive 90, it is not necessary to fix the stator 20 directly to the housing 50. As a result, when selecting a material for the housing 50, it is not necessary to consider the need to fix and hold the stator 20 to the housing 50. This increases the degree of freedom in selecting a material for the housing 50. Specifically, the rigidity required for the housing 50 can be reduced compared to when the stator 20 is fixed and held to the housing 50. As a result, cheaper materials can be used to construct the housing 50. This reduces the manufacturing cost of the housing 50. Furthermore, the amount of material required to manufacture the housing 50 tends to be greater than the amount of material required to manufacture the accommodating member 70. Therefore, by manufacturing the housing 50 using cheaper materials and reducing the manufacturing cost of the housing 50, the manufacturing cost of the entire pump 100 can be easily reduced.

[0062] At least a portion of the adhesive 90 is located in a gap G1 between the radially outer surface of the second outer protrusion 22b and the radially inner surface of the second cylindrical portion 73. Therefore, by applying uncured adhesive 90 to at least one of the radially outer surface of the second outer protrusion 22b and the radially inner surface of the second cylindrical portion 73 and then inserting the second outer protrusion 22b into the second cylindrical portion 73, the insulator 22 can be fixed to the second cylindrical portion 73 with the adhesive 90. This makes it easy to fix the insulator 22 to the accommodating member 70. In this embodiment, a portion of the adhesive 90 is located in the gap G1. The portion of the adhesive 90 located in the gap G1 bonds the radially outer surface of the second outer protrusion 22b and the radially inner surface of the second cylindrical portion 73 together.

[0063] In this embodiment, a portion of the adhesive 90 is located inside the groove 72a. Therefore, when the uncured adhesive 90 is applied to fix the insulator 22 and the accommodating member 70, a portion of the uncured adhesive 90 can escape into the groove 72a. This prevents a portion of the uncured adhesive 90 from flowing radially inward from the second outer protrusion 22b. This prevents a portion of the adhesive 90 from adhering to the coil 23. If the adhesive 90 adheres to the coil 23, the enamel coating on the surface of the coil 23 may peel off when the coil 23 is subjected to a thermal shock. However, in this embodiment, the groove 72a prevents the adhesive 90 from adhering to the coil 23, thereby preventing the enamel coating on the surface of the coil 23 from peeling off. Furthermore, even if there is variation in the amount of uncured adhesive 90 applied to at least one of the radially outer surface of the second outer protrusion 22b and the radially inner surface of the second cylindrical portion 73, some of the uncured adhesive 90 can escape into the groove 72a. Therefore, the worker or the like who applies the uncured adhesive 90 can easily control the amount of adhesive 90.

[0064] In this specification, the term "workers, etc." includes the workers who perform each task and the equipment, etc. Each task may be performed by the worker alone, by the equipment alone, or by both the worker and the equipment.

[0065] In this embodiment, a portion of adhesive 90 is located between the bottom surface of groove 72 a and the lower end surface of second outer protrusion 22 b. The portion of adhesive 90 located between the bottom surface of groove 72 a and the lower end surface of second outer protrusion 22 b bonds the bottom surface of groove 72 a to the lower end surface of second outer protrusion 22 b.

[0066] In this embodiment, the adhesive 90 is a thermosetting adhesive. Therefore, even if the stator 20 generates heat and the cured adhesive 90 is subjected to heat, the adhesive strength of the adhesive 90 can be prevented from decreasing. This prevents the stator 20 and the housing member 70 from being loosened. Furthermore, if the adhesive 90 is a thermosetting adhesive, if a portion of the adhesive 90 adheres to the coil 23, the enamel coating on the surface of the coil 23 is particularly likely to peel off when subjected to thermal shock. However, in this embodiment, by providing the grooves 72a as described above, the adhesive 90 can be prevented from adhering to the coil 23. In other words, the effect obtained by providing the grooves 72a is particularly useful when the adhesive 90 is a thermosetting adhesive. The adhesive 90 is, for example, a one-component epoxy adhesive.

[0067] As shown in FIG. 1 , the busbar assembly 80 is located above the lid portion 71a. The busbar assembly 80 is supported from below by the lid portion 71a. The busbar assembly 80 is fixed to the lid portion 71a. As shown in FIG. 11 , the busbar assembly 80 includes a busbar holder 81, a busbar 82, and a ground connection member 83. The busbar 82 and the ground connection member 83 are held by the busbar holder 81. The busbar 82 is electrically connected to the coil 23 provided in the stator 20. The ground connection member 83 contacts the stator core 21. In this manner, in this embodiment, the busbar 82 electrically connected to the coil 23 and the ground connection member 83 in contact with the stator core 21 are held by the busbar holder 81 and integrated into the busbar assembly 80. As a result, by disposing the bus bar assembly 80 above the lid portion 71a of the housing member 70, the bus bar 82 and the ground connection member 83 can be disposed together. This makes it easier to assemble the bus bar 82 and the ground connection member 83 than if the bus bar 82 and the ground connection member 83 were disposed separately. This improves the ease of assembly of the pump 100.

[0068] The bus bar holder 81 holds the bus bars 82 and the ground connection members 83. The bus bar holder 81 is made of resin. In this embodiment, the bus bar holder 81 is made by insert molding using the bus bars 82 and the ground connection members 83 as insert members. The bus bar holder 81 has a holder main body portion 81a, a terminal support portion 81b, and a cover portion 81c.

[0069] The holder main body 81a holds the bus bar 82 and the ground connection member 83. In this embodiment, the holder main body 81a has a generally circular plate shape centered on the central axis J. As shown in FIG. 1 , the radial outer edge of the holder main body 81a is located radially outward from the first cylindrical portion 71b. The radial outer edge of the holder main body 81a is located radially outward from the first inner protrusion 22c and the second inner protrusion 22d, and radially inward from the first outer protrusion 22a and the second outer protrusion 22b. The radial outer edge of the holder main body 81a is located above and spaced apart from the coil 23.

[0070] As shown in Figure 11, the terminal support portion 81b protrudes upward from the upper surface of the holder main body portion 81a. The terminal support portion 81b has a generally rectangular parallelepiped shape extending in the radial direction. A central axis J passes through the terminal support portion 81b. The terminal support portion 81b supports the lower ends of the bus bar terminal portions 82a and the ground terminal portions 83a, which will be described later.

[0071] The cover portion 81c protrudes radially outward from the holder main body portion 81a. The cover portion 81c is located lower than the holder main body portion 81a. In this embodiment, the radially inner end of the cover portion 81c is connected to the lower surface of the holder main body portion 81a. The cover portion 81c has a substantially rectangular parallelepiped shape. As shown in FIG. 4, the cover portion 81c extends at an angle in the circumferential direction relative to the radial direction. The radially outer end of the cover portion 81c is located radially outward from the coil lead wire 23a extending upward from the coil 23. The coil lead wire 23a is formed by the end of a conducting wire that constitutes the coil 23.

[0072] As shown in FIG. 6 , the bus bar holder 81 has a tubular portion 81d that protrudes downward from the lower surface of the holder main body portion 81a. The tubular portion 81d is cylindrical and opens downward. In this embodiment, the tubular portion 81d is cylindrical and centered on the central axis J. The holder main body portion 81a and the tubular portion 81d form a positioned portion 81e, which is a recess that is recessed upward. In other words, the bus bar holder 81 has the positioned portion 81e. The interior of the positioned portion 81e, which is a recess, is the interior of the tubular portion 81d. The upper surface of the inner surface of the positioned portion 81e, which is a recess, is the axial bottom surface 81f of the inner surface of the positioned portion 81e, which is a recess. The bottom surface 81f faces downward. The bottom surface 81f is the portion of the lower surface of the holder main body portion 81a that is surrounded by the tubular portion 81d when viewed in the axial direction.

[0073] The positioned portion 81e is a portion that is positioned by the positioning portion 75. The positioning portion 75 positions the busbar assembly 80 in at least one direction by positioning the positioned portion 81e. As a result, when the busbar assembly 80 is placed above the lid portion 71a of the accommodating member 70, the busbar assembly 80 can be positioned in at least one direction using the accommodating member 70. This makes it easier to assemble the busbar assembly 80 during assembly of the pump 100, further improving the assemblability of the pump 100. Furthermore, because the busbar assembly 80 can be positioned relative to the accommodating member 70, which is provided with the lid portion 71a that holds the fixed shaft 30, the busbar assembly 80 can be accurately positioned relative to the central axis J. This allows the busbar assembly 80 to be accurately positioned relative to the rotor 10, which is rotatably supported by the fixed shaft 30. This also makes it easier to accurately position the busbar assembly 80 relative to the stator 20, which is positioned radially outward of the rotor 10. This makes it easier to connect the bus bars 82 of the bus bar assembly 80 to the coils 23 of the stator 20 .

[0074] In the present embodiment, as described above, the radially inner surfaces of the teeth 25 contact the first ribs 76, thereby positioning the stator 20 radially relative to the accommodating member 70. Furthermore, because the rotor 10 is rotatably supported by the fixed shaft 30 fixed to the accommodating member 70, the rotor 10 is also positioned radially relative to the accommodating member 70 via the fixed shaft 30. As a result, in the present embodiment, the rotor 10, the stator 20, and the bus bar assembly 80 can be positioned relative to the accommodating member 70. Therefore, the relative positional accuracy of the rotor 10, the stator 20, and the bus bar assembly 80 can be improved compared to when the rotor 10, the stator 20, and the bus bar assembly 80 are positioned relative to different members. This allows the pump 100 to be assembled with high precision.

[0075] The positioning portion 75, which is a convex portion, is fitted into the positioned portion 81e, which is a concave portion. Therefore, the positioning portion 75 can position the busbar assembly 80 in the radial direction. In this embodiment, the positioning portion 75 is loosely fitted into the positioned portion 81e. Note that the positioning portion 75 may be press-fitted into the positioned portion 81e. The upper end surface of the positioning portion 75, which is a convex portion, contacts the axial bottom surface 81f of the inner surface of the positioned portion 81e, which is a concave portion. Therefore, the positioning portion 75 can position the busbar assembly 80 in the axial direction. As a result, according to this embodiment, the positioning portion 75 can position the busbar assembly 80 in the radial and axial directions with respect to the accommodating member 70.

[0076] An adhesive 91 for fixing the bus bar holder 81 and the accommodating member 70 is provided inside a recess 75a provided on the axial end surface of the positioning portion 75. By storing the adhesive 91 inside the recess 75a, the axial end surface of the positioning portion 75 can be brought into contact with the bottom surface 81f of the positioned portion 81e, and the adhesive 91 can fix the bus bar holder 81 and the accommodating member 70. Furthermore, by applying uncured adhesive 91 to at least one of the recess 75a and the bottom surface 81f, and then fitting the positioning portion 75 into the positioned portion 81e, the bus bar holder 81 and the accommodating member 70 can be easily fixed. This further improves the assembly of the pump 100. In this embodiment, the adhesive 91 is a thermosetting adhesive. The adhesive 91 is, for example, a one-component epoxy adhesive. The adhesive 91 may be the same type of adhesive as the adhesive 90 that fixes the insulator 22 to the accommodating member 70 , or may be a different type of adhesive from the adhesive 90 .

[0077] In this embodiment, the positioned portions 81e have a circular shape centered on the central axis J when viewed in the axial direction. That is, in this embodiment, the positioning portions 75, which are convex portions, and the positioned portions 81e, which are concave portions, have a circular shape centered on the central axis J when viewed in the axial direction. Therefore, when assembling the busbar assembly 80 to the accommodating member 70, the positioning portions 75 are fitted into the positioned portions 81e to position the busbar assembly 80 in the radial direction, while the busbar assembly 80 can be rotated slightly in the circumferential direction. This makes it possible, when assembling the busbar assembly 80, to adjust the circumferential position of the busbar assembly 80 while the busbar assembly 80 is positioned in the radial direction.

[0078] Furthermore, in this embodiment, the positioning portion 75 provided on the accommodating member 70 is a convex portion that protrudes upward, and the positioned portion 81e provided on the bus bar holder 81 is a concave portion that is recessed upward. Therefore, the fixed shaft 30 can be positioned higher in the axial direction than when the accommodating member 70 is provided with a concave portion that is recessed downward. This makes it easier to reduce the axial dimension of the portion of the fixed shaft 30 that protrudes downward from the cover portion 71a, and prevents the pump 100 from becoming larger in the axial direction.

[0079] 11 , the ground connection member 83 is a plate-shaped metal member. The ground connection member 83 is a member that is electrically connected to a ground portion of a circuit board (not shown). The circuit board (not shown) is provided, for example, in an external device that is connected to the pump 100 via the connector portion 51d. The bus bar 82, for example, is also electrically connected to the circuit board. The circuit board is provided with an inverter circuit that supplies power to the coil 23. The circuit board may also be provided in the pump 100. In this case, the circuit board is accommodated inside the housing 50 and is disposed, for example, above the bus bar assembly 80.

[0080] The contact of the ground connection member 83 with the stator core 21 electrically connects the ground portion of a circuit board (not shown) to the stator core 21. This allows the ground portion of the circuit board to be connected to the metal stator core 21, which has a relatively large volume. This makes it easier to stabilize the reference potential of the ground portion of the circuit board.

[0081] The ground connection member 83 has a ground terminal portion 83a, a first extension portion 83b, a second extension portion 83c, and a third extension portion 83d. The first extension portion 83b extends in the axial direction. The first extension portion 83b is plate-shaped with its plate surface facing in the radial direction. The first extension portion 83b is exposed to the outside of the busbar holder 81. A lower end of the first extension portion 83b is located below the busbar holder 81. As shown in FIG. 1 , the lower end of the first extension portion 83b is inserted into the hole 26. This allows the ground connection member 83 to contact the stator core 21 via the first extension portion 83b. Furthermore, inserting the first extension portion 83b into the hole 26 allows the busbar assembly 80 to be positioned circumferentially relative to the stator 20. This makes it easy to circumferentially align the coil lead wires 23a extending from the coil 23 with the bus bar 82. Therefore, the coil 23 and the bus bar 82 can be easily electrically connected.

[0082] In the present embodiment, the first extension portion 83b is press-fit into the hole 26. As shown in FIG. 11 , a protrusion 83e is provided on each of both circumferential side surfaces of a lower portion of the first extension portion 83b. A plurality of protrusions 83e are provided on each of the both side surfaces and lined up in the axial direction. The portion of the first extension portion 83b where the protrusion 83e is provided is inserted into the hole 26. The protrusion 83e comes into contact with the circumferential side surface of the hole 26, thereby preventing the first extension portion 83b from slipping out of the hole 26 upward. As shown in FIG. 3 , the portion of the first extension portion 83b located above the hole 26 is passed axially through the groove 22g.

[0083] As shown in FIG. 11 , the second extension portion 83c extends radially inward from the upper end of the first extension portion 83b. The second extension portion 83c is plate-shaped with its plate surface facing the axial direction. The second extension portion 83c is located lower than the coil connection portion 82c described below. This prevents the second extension portion 83c from getting in the way when connecting the coil lead wire 23a to the coil connection portion 82c. This facilitates the process of connecting the coil lead wire 23a to the coil connection portion 82c. This also prevents the second extension portion 83c from coming into contact with the coil connection portion 82c. Furthermore, the first extension portion 83b can be positioned lower than when the second extension portion 83c is located at the same axial position as the coil connection portion 82c or higher than the coil connection portion 82c. Therefore, for example, it is easy to insert the lower end of the first extending portion 83b into the hole 26 before the coil connection portion 82c is at the same axial position as the upper end of the coil lead-out wire 23a. This makes it possible to bring the coil connection portion 82c close to the coil lead-out wire 23a while positioning the coil lead-out wire 23a circumferentially relative to the coil connection portion 82c. This makes it easier to connect the coil connection portion 82c and the coil lead-out wire 23a.

[0084] In the present embodiment, at least a portion of the second extension portion 83c is embedded in the cover portion 81c. This prevents the second extension portion 83c from coming into contact with the coil lead-out wire 23a, thereby preventing a short circuit between the coil 23 and the ground connection member 83. In the present embodiment, the radially outer end of the cover portion 81c is located radially outward of the coil lead-out wire 23a. This allows the cover portion 81c to cover the second extension portion 83c up to a position radially outward of the coil lead-out wire 23a. This further prevents contact between the second extension portion 83c and the coil lead-out wire 23a, thereby further preventing a short circuit between the coil 23 and the ground connection member 83. In the present embodiment, the entire second extension portion 83c, except for the radially outer end, is embedded in the cover portion 81c.

[0085] The third extension portion 83d is connected to the radially inner end of the second extension portion 83c. The third extension portion 83d is located above the second extension portion 83c. The third extension portion 83d is plate-shaped with its plate surface facing the axial direction. The third extension portion 83d is embedded in the holder main body portion 81a.

[0086] The ground terminal portion 83a extends upward from the end of the third extending portion 83d opposite to the end connected to the second extending portion 83c. The ground terminal portion 83a is plate-shaped with its plate surface facing a direction perpendicular to the axial direction. The ground terminal portion 83a protrudes upward from the terminal support portion 81b. As shown in FIG. 6 , a portion of the ground terminal portion 83a is exposed inside the connector portion 51d. The portion of the ground terminal portion 83a exposed inside the connector portion 51d is electrically connected to a terminal of an external device connected to the connector portion 51d. This electrically connects the ground terminal portion 83a to a ground portion of a circuit board of the external device via the terminal.

[0087] As shown in FIG. 11 , the busbar 82 is a plate-shaped metal member. A plurality of busbars 82 are provided. In this embodiment, three busbars 82 are provided. Each busbar 82 has a busbar terminal portion 82a, a busbar main body portion 82b, and a coil connection portion 82c. The busbar terminal portion 82a extends upward from the busbar main body portion 82b. The busbar terminal portion 82a protrudes upward from the terminal support portion 81b. The busbar terminal portion 82a is plate-shaped with its plate surface facing a direction perpendicular to the axial direction. The busbar terminal portions 82a of the plurality of busbars 82 and the ground terminal portion 83a of the ground connection member 83 are arranged side by side in the extension direction of the terminal support portion 81b. The plate surfaces of the busbar terminal portions 82a and the ground terminal portions 83a face the same direction.

[0088] As shown in Fig. 6, a portion of the busbar terminal portion 82a is exposed inside the connector portion 51d. The busbar terminal portion 82a is electrically connected to a terminal of an external device connected to the connector portion 51d. The busbar terminal portion 82a is electrically connected to an inverter circuit on a circuit board provided in the external device via the terminal. As shown in Fig. 11, the busbar main body portion 82b is plate-shaped with its plate surface facing the axial direction. The busbar main body portion 82b extends along a plane perpendicular to the axial direction. The busbar main body portion 82b is embedded inside the holder main body portion 81a.

[0089] The coil connection portion 82c is connected to the coil lead wire 23a extending upward from the coil 23. The coil connection portion 82c protrudes radially outward from the bus bar holder 81. Therefore, when assembling the bus bar assembly 80, the first extension portion 83b is inserted into the hole portion 26 to position the bus bar assembly 80 in the circumferential direction, and then the coil lead wire 23a can be brought closer to the coil connection portion 82c from the radially outer side to connect the coil lead wire 23a and the coil connection portion 82c to each other. As described above, in this embodiment, compared to connecting the bus bar 82 and the ground connection member 83 separately to the stator 20 while paying attention to their relative positions, it is only necessary to insert only the first extension portion 83b into the hole portion 26 to position the bus bar assembly 80, which makes it easier to assemble the bus bar assembly 80. This further improves the ease of assembly of the pump 100.

[0090] In this embodiment, the coil connection portion 82c protrudes radially outward from the radially outer surface of the holder main body portion 81a. The coil connection portion 82c has an arm portion 82d and a pair of clamping portions 82e, 82f. The arm portion 82d protrudes radially outward from the bus bar holder 81. The arm portion 82d is plate-shaped with its plate surface facing the axial direction. The pair of clamping portions 82e, 82f connect to the radially outer end of the arm portion 82d. The pair of clamping portions 82e, 82f and the radially outer end of the arm portion 82d form a generally U-shaped configuration that opens radially outward when viewed in the axial direction. As shown in FIG. 4 , the pair of clamping portions 82e, 82f clamp the coil lead wire 23a in the circumferential direction. The pair of clamping portions 82e, 82f are connected to the coil lead wire 23a by, for example, welding. With the bus bar assembly 80 positioned in the circumferential direction via the ground connection member 83, an operator can insert each coil lead wire 23a between the pair of clamping portions 82e, 82f of each coil connection portion 82c from the radially outer side. Note that the pair of clamping portions 82e, 82f may be crimped in a direction approaching each other in the circumferential direction so as to come into contact with each other with the coil lead wire 23a sandwiched between the pair of clamping portions 82e, 82f. In this embodiment, two coil connection portions 82c are provided on each bus bar 82.

[0091] 12 , the busbar assembly 80 is brought close from above to the accommodating member 70 with the stator 20 assembled thereto, and fixed to the accommodating member 70. Before the busbar assembly 80 is assembled to the accommodating member 70, uncured adhesive 91 is applied to the recesses 75a of the positioning portions 75. When the busbar assembly 80 is brought close to the stator 20 and the accommodating member 70 in the axial direction, the lower ends of the first extending portions 83b of the ground connection members 83 are inserted into the holes 26, and the busbar assembly 80 is positioned in the circumferential direction. When the busbar assembly 80 is further brought close to the stator 20 and the accommodating member 70 in the axial direction, the positioning portions 75, which are protrusions, fit into the positioned portions 81e, which are recesses, and the busbar assembly 80 is positioned in the radial direction. When the busbar assembly 80 is further brought closer to the stator 20 and the accommodating member 70 in the axial direction, the bottom surfaces 81f of the positioned portions 81e come into contact with the upper end surfaces of the positioning portions 75, thereby positioning the busbar assembly 80 in the axial direction. As a result, the busbar assembly 80 is assembled to the accommodating member 70 while being positioned circumferentially, radially, and axially. In this state, the uncured adhesive 91 cures, thereby fixing the busbar assembly 80 to the accommodating member 70.

[0092] The present invention is not limited to the above-described embodiments, and other configurations and methods may be adopted within the scope of the technical concept of the present invention. The number of first ribs is not particularly limited as long as it is one or more. The first rib may have any shape as long as it extends in the axial direction. The first rib may not be provided. When a second rib is provided, the number of second ribs is not particularly limited as long as it is one or more. The second rib may not be provided. When a third rib is provided, the number of third ribs is not particularly limited as long as it is one or more. The third rib may not be provided. The fourth rib, fifth rib, and sixth rib described in the above-described embodiments may not be provided.

[0093] When the accommodating member has a positioning portion that positions the busbar assembly, the positioning portion may position the busbar assembly in any direction. The positioning portion may position the busbar assembly in the circumferential direction relative to the accommodating member. The shape of the positioning portion is not particularly limited. The positioning portion may be a recess. In this case, the positioned portion provided on the busbar holder is, for example, a protrusion that fits into the positioning portion.

[0094] When the stator is fixed to the housing member with an adhesive, portions of the stator other than the insulator may be fixed to the housing member with the adhesive. When the stator is fixed to the housing member with an adhesive, the adhesive may be applied to any location. The adhesive may be of any type as long as it can fix the stator to the housing member. The bottom of the housing member does not need to be provided with a groove in which part of the adhesive is located. The stator may be fixed to the housing member by a method other than adhesive.

[0095] The ground connection member may contact the stator core in any manner as long as it contacts the stator core. The ground connection member may contact an axial end face of the stator core or a radially outer surface of the stator core. When the first extension portion of the ground connection member is inserted into a hole, the hole may be provided anywhere in the stator core. The ground connection member may be held in any manner by the busbar holder. The ground connection member may have any configuration as long as it contacts the stator core. The coil connection portion of the busbar may protrude from the busbar holder in any manner. The coil connection portion may have any shape as long as it is connected to the coil lead wire. The busbar may be held in the busbar holder in any manner.

[0096] The pumps in the above-described embodiments may be pumps that pump fluids other than water, or may be oil pumps that pump oil. The uses of the pumps are not particularly limited.

[0097] The present technology may be configured as follows: (1) A pump including: a rotor rotatable about a central axis; a stator located radially outside the rotor and surrounding the rotor; a pump unit connected to one axial side of the rotor; a housing member that houses the rotor; and a busbar assembly having busbars electrically connected to coils provided on the stator and a busbar holder that holds the busbars, wherein the housing member has a lid that covers the rotor from the other axial side, a cylindrical portion located radially between the rotor and the stator and opening to the one axial side, and a bottom portion that extends radially outward from the cylindrical portion and covers the stator from the one axial side, the stator has a stator core located radially outside the cylindrical portion, and the busbar assembly has a ground connection member held by the busbar holder and is located on the other axial side of the lid, the ground connection member being in contact with the stator core. (2) The pump according to (1), wherein the stator core has a hole recessed on one axial side, and the ground connection member has a first extension extending in the axial direction, an end portion on one axial side of the first extension located on one axial side of the bus bar holder and inserted into the hole. (3) The pump according to (2), wherein the bus bar has a coil connection portion connected to a coil lead wire extending from the coil on the other axial side, the coil connection portion protruding radially outward from the bus bar holder. (4) The pump according to (3), wherein the ground connection member has a second extension portion extending radially inward from an end portion on the other axial side of the first extension portion, the second extension portion located on one axial side of the coil connection portion. (5) The pump according to (4), wherein the bus bar holder has a holder main body portion that holds the bus bar and a cover portion that protrudes radially outward from the holder main body portion, and at least a portion of the second extension portion is embedded in the cover portion. (6) The pump according to (5), wherein a radially outer end of the cover portion is positioned radially outward of the coil lead wire.(7) The pump according to any one of (2) to (6), wherein the stator core has an annular core back surrounding the cylindrical portion and a plurality of teeth extending radially inward from the core back and spaced apart in a circumferential direction, and the hole is provided in the core back. (8) The pump according to (7), wherein the hole has a portion provided at the same circumferential position as a circumferential center of one of the teeth. (9) The pump according to any one of (1) to (8), comprising a fixed shaft extending in the axial direction and rotatably supporting the rotor, the cover portion holding an end portion on the other axial side of the fixed shaft, and the accommodating member having a positioning portion that positions the bus bar assembly in at least one direction. (10) The pump according to (9), wherein the positioning portion is provided on the lid portion, the bus bar holder has a positioned portion that is positioned by the positioning portion, one of the positioning portion and the positioned portion being a convex portion that protrudes in the axial direction, and the other of the positioning portion and the positioned portion being a concave portion into which the convex portion is fitted. (11) The pump according to (10), wherein an axial end face of the convex portion contacts an axial bottom surface of an inner surface of the concave portion. (12) The pump according to (11), wherein a concave portion is provided on the axial end face of the convex portion, and an adhesive is provided inside the concave portion to fix the bus bar holder and the accommodating member. (13) The pump according to any one of (10) to (12), wherein the convex portion and the concave portion have a circular shape centered on the central axis when viewed in the axial direction. (14) The pump according to any one of (10) to (13), wherein the positioning portion is the convex portion that protrudes to the other axial side, and the positioned portion is the concave portion that is recessed to the other axial side. (15) The pump according to (14), wherein the end face of the fixed shaft on the other axial side is embedded inside the positioning portion.

[0098] The configurations and methods described in this specification can be combined as appropriate within the scope of not being mutually contradictory.

[0099] DESCRIPTION OF SYMBOLS 10...rotor, 20...stator, 21...stator core, 23...coil, 23a...coil lead wire, 24...core back, 25...teeth, 26...hole portion, 30...fixed shaft, 40...pump portion, 70...accommodating member, 71a...lid portion, 71b...first cylindrical portion (cylindrical portion), 72...bottom portion, 75...positioning portion (convex portion), 75a...recessed portion, 80...busbar assembly, 81...busbar holder, 81a...holder main body portion, 81c...cover portion, 81e...positioned portion (recessed portion), 81f...bottom surface, 82...busbar, 82c...coil connection portion, 83...ground connection member, 83b...first extension portion, 83c...second extension portion, 91...adhesive, 100...pump, J...central axis line

Claims

1. A pump comprising: a rotor rotatable about a central axis; a stator located radially outward of the rotor and surrounding the rotor; a pump section connected to one axial side of the rotor; a housing member for housing the rotor internally; and a busbar assembly having a busbar electrically connected to a coil provided on the stator and a busbar holder for holding the busbar, wherein the housing member has: a lid portion covering the rotor from the other axial side; a cylindrical portion located radially between the rotor and the stator and opening to the one axial side; and a bottom portion extending radially outward from the cylindrical portion and covering the stator from the one axial side, wherein the stator has a stator core located radially outward of the cylindrical portion, and the busbar assembly has a ground connection member held by the busbar holder and is located on the other axial side of the lid portion, and the ground connection member is in contact with the stator core.

2. The pump as described in claim 1, wherein the stator core has a hole recessed on one axial side, the ground connection member has a first extension portion extending in the axial direction, and an end portion on one axial side of the first extension portion is located on the one axial side of the bus bar holder and is inserted into the hole portion.

3. A pump as set forth in claim 2, wherein the bus bar has a coil connection portion connected to a coil lead wire extending from the coil to the other axial side, the coil connection portion protruding radially outward from the bus bar holder.

4. A pump as described in claim 3, wherein the ground connection member has a second extension portion extending radially inward from an end portion on the other axial side of the first extension portion, and the second extension portion is located on one axial side of the coil connection portion.

5. The pump according to claim 4, wherein the bus bar holder has a holder main body portion that holds the bus bar, and a cover portion that protrudes radially outward from the holder main body portion, and at least a portion of the second extension portion is embedded in the cover portion.

6. The pump according to claim 5, wherein a radially outer end of said cover portion is located radially outward of said coil lead wire.

7. A pump as described in claim 2, wherein the stator core has: an annular core back surrounding the cylindrical portion; and a plurality of teeth extending radially inward from the core back and spaced apart in the circumferential direction; and the hole portion is provided in the core back.

8. The pump according to claim 7, wherein the hole has a portion that is provided at the same circumferential position as the circumferential center of one of the teeth.

9. A pump as claimed in any one of claims 1 to 8, further comprising a fixed shaft extending in the axial direction and rotatably supporting the rotor, the cover portion holding the other axial end of the fixed shaft, and the housing member having a positioning portion for positioning the busbar assembly in at least one direction.

10. A pump as described in claim 9, wherein the positioning portion is provided on the lid portion, the busbar holder has a positioned portion that is positioned by the positioning portion, one of the positioning portion and the positioned portion is a convex portion that protrudes in the axial direction, and the other of the positioning portion and the positioned portion is a concave portion into which the convex portion is fitted.

11. The pump according to claim 10, wherein an axial end face of the protrusion contacts an axial bottom face of an inner surface of the recess.

12. The pump according to claim 11, wherein a recess is provided on an axial end face of the protrusion, and an adhesive is provided inside the recess to fix the bus bar holder and the accommodating member.

13. The pump according to claim 10, wherein the convex portion and the concave portion are circular about the central axis when viewed in the axial direction.

14. The pump according to claim 10, wherein the positioning portion is the convex portion protruding to the other axial side, and the positioned portion is the concave portion recessed to the other axial side.

15. The pump according to claim 14, wherein the other axial end face of the fixed shaft is embedded inside the positioning portion.

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