One aspect of a pump of the present invention includes a rotor rotatable about a central axis, a stator assembly located radially outside the rotor and surrounding the rotor, a pump unit connected to a first side in an axial direction of the rotor, a support member including a rotor accommodating portion, the rotor accommodating portion being located radially inside the stator assembly and accommodates the rotor therein, and a resin housing in which the stator assembly and the support member are molded. The rotor accommodating portion includes a lid portion that covers the rotor from a second side in the axial direction, and a tubular portion that is located between the rotor and the stator assembly in a radial direction and is open to the first side in the axial direction. The stator assembly includes a stator core having an annular shape, a plurality of coils mounted on the stator core, and a stator cover that covers the plurality of coils.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2021-115272 filed on Jul. 12, 2021, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a pump.

BACKGROUND

An electric pump in which a motor unit and a pump unit are integrated in advance has been developed. Conventionally, there is known a pump in which a motor unit and a pump unit are integrated, the pump having a structure in which a stator is molded in order to ensure waterproofness of the stator.

As described above, when a stator is molded, molding resin and a coil are in direct contact with each other. For this reason, a coil wire may have been damaged by heat and injection pressure during molding of the mold resin.

SUMMARY

One aspect of an exemplary pump of the present invention includes a rotor rotatable about a central axis, a stator assembly located radially outside the rotor and surrounding the rotor, a pump unit connected to a first side in an axial direction of the rotor, a support member including a rotor accommodating portion, the rotor accommodating portion being located radially inside the stator assembly and accommodating the rotor therein, and a resin housing in which the stator assembly and the support member are molded. The rotor accommodating portion includes a lid portion that covers the rotor from a second side in the axial direction, and a tubular portion that is located between the rotor and the stator assembly in a radial direction and is open to the first side in the axial direction. The stator assembly includes a stator core having an annular shape, a plurality of coils mounted on the stator core, and a stator cover that covers the plurality of coils.

DETAILED DESCRIPTION

Each diagram virtually illustrates a central axis J in a pump1of an embodiment described below. In description below, the axial direction of the central axis J is simply referred to as the “axial direction”. A radial direction around the central axis J is simply referred to as the “radial direction”. A circumferential direction around the central axis J is simply referred to as the “circumferential direction”. A Z axis illustrated in each diagram indicates a direction in which the central axis J extends. In description below, the side of the axial direction to which an arrow of the Z axis is directed (+Z side) is referred to as the “upper side”, and the side of the axial direction opposite to the side to which the arrow of the Z axis is directed (−Z side) is referred to as the “lower side”.

In the present embodiment, the lower side corresponds to the “first side in the axial direction”, and the upper side corresponds to the “second side in the axial direction”. Note that the upper side and the lower side are simply terms for describing a relative positional relationship of components, and an actual arrangement relationship and the like may be an arrangement relationship and the like other than the arrangement relationship and the like indicated by these terms.

FIG.1is a perspective view of the pump1.FIG.2is a cross-sectional view of the pump1.FIGS.3,4,5, and6are enlarged views each enlarging a part ofFIG.2. InFIG.2, for the sake of explanation, cross sections at different circumferential positions on both the left and right sides of the central axis J are illustrated.

As illustrated inFIG.2, the pump1of the present embodiment includes a motor3, a pump unit60, a support member10, a fixed shaft40, a circuit board80, and a case2. The motor3includes a rotor50rotatable about the central axis J, and a stator assembly75located radially outside the rotor50and surrounding the rotor50. That is, the pump1includes the rotor50and the stator assembly75.

The pump1of the present embodiment is a water pump that sends water. The pump1discharges water (liquid) sucked from an inlet pipe26from an outlet pipe27(seeFIG.1) by rotating the pump unit60by the motor3.

As illustrated inFIG.2, the case2accommodates the motor3, the pump unit60, the support member10, the fixed shaft40, and the circuit board80. The inside of the case2is divided into a flow path region A2through which water (liquid) passes and a waterproof region A1sealed from water. The rotor50, the fixed shaft40, and the pump unit60are arranged in the flow path region A2. In the waterproof region A1, the stator assembly75and the circuit board80are arranged. The flow path region A2and the waterproof region A1are defined by the support member10.

The case2includes a resin housing (motor housing)30, a substrate cover28, and a pump cover20. That is, the pump1includes the resin housing30, the substrate cover28, and the pump cover20. The substrate cover28is joined to an upper end portion of the resin housing30. On the other hand, the pump cover20is joined to a lower end portion of the resin housing30. In this manner, the resin housing30, the substrate cover28, and the pump cover20are fixed to each other.

The resin housing30includes an embedded portion32in which the stator assembly75and the support member10are embedded. That is, the resin housing30is formed by insert molding in which the stator assembly75and the support member10are inserted. In this manner, the resin housing30holds the stator assembly75and the support member10. The resin housing30surrounds the stator70, the rotor50, and a rotor accommodating portion12from radially outside.

As illustrated inFIG.1, an outer peripheral surface30aof the resin housing30is circular when viewed from the axial direction. A connector portion39is provided on the outer peripheral surface30aof the resin housing30. That is, the resin housing30has the connector portion39. The connector portion39protects a terminal8connected to an external device7.

As illustrated inFIG.2, an upper end portion of the resin housing30is provided with a housing upper surface30gfacing upward and a surrounding tubular portion38extending upward from an outer edge of the upper surface30g. On the other hand, a holding tubular portion31having a tubular shape around the central axis J is provided in a lower end portion of the resin housing30. The resin housing30is joined to the substrate cover28at the surrounding tubular portion38, and is joined to the pump cover20at the holding tubular portion31.

The housing upper surface30gfaces the circuit board80in the vertical direction. The housing upper surface30gis provided with a boss that supports the circuit board80from below. The surrounding tubular portion38has a cylindrical shape around the central axis J. The surrounding tubular portion38surrounds the circuit board80from radially outside.

The substrate cover28includes a cover main body28ahaving a plate shape extending along a plane orthogonal to the central axis J, and a guide rib28bprovided on a lower surface of the cover main body28a. The cover main body28ahas a circular shape around the central axis J. An outer diameter of the cover main body28asubstantially matches an outer diameter of the resin housing30. The guide rib28bextends along the circumferential direction. The guide rib28bis arranged slightly further on the radially inner side than an outer edge of the cover main body28a. An outer peripheral surface of the guide rib28bis fitted to an inner peripheral surface of the surrounding tubular portion38of the resin housing30. In this manner, the substrate cover28is positioned with respect to the resin housing30.

A region located radially outside the guide rib28bon a lower surface of the cover main body28ais in contact with an upper end surface of the surrounding tubular portion38of the resin housing30. A lower surface of the cover main body28aand an upper end surface of the surrounding tubular portion38are welded to each other.

In a welding process, the substrate cover28is rotated while having a lower surface pressed against the resin housing30. In the welding process, a contact portion between the substrate cover28and the resin housing30is melted by frictional heat and solidified to be joined. That is, the substrate cover28and the resin housing30are joined by spin welding. The substrate cover28and the resin housing30may be welded by other welding means such as ultrasonic welding and laser welding.

The circuit board80is arranged on the upper side (the second side in the axial direction) of the stator assembly75. That is, the circuit board80is arranged on the upper side of the stator70. The circuit board80is accommodated in a space surrounded by the radially inner side of the surrounding tubular portion38of the resin housing30, the housing upper surface30g, and the substrate cover28.

The circuit board80includes a substrate main body81having a plate shape along a plane orthogonal to the central axis J, and a heat generating element82mounted on an upper surface81a(surface on the second side in the axial direction) of the substrate main body81. In addition to the heat generating element82, the circuit board80includes a plurality of elements (not illustrated) mounted on the upper surface81aor a lower surface81bof the substrate main body81.

The substrate main body81has a first through hole (through hole)81hand a second through hole81kpenetrating in the thickness direction. That is, the circuit board80is provided with the first through hole81hand the second through hole81k. A coil wire73aextending upward from the stator assembly75is inserted into the first through hole81hand solder-connected to the substrate main body81. A first end portion8aof the terminal8is inserted into the second through hole81kand solder-connected to the substrate main body81. The plurality of first through holes81hand the plurality of second through holes81kare provided on the substrate main body81.

The heat generating element82is arranged on the central axis J. The heat generating element82means an element that generates heat during operation and has a high temperature among elements mounted on the substrate main body81. When the circuit board80has a plurality of elements, the heat generating element82generates a larger amount of heat than other elements. Examples of the heat generating element82include a switching element, a capacitor, a field effect transistor, a driver integrated circuit for driving a field effect transistor, and an integrated circuit for a power supply.

A support member (shield member)10is made from a non-magnetic material. In the present embodiment, the support member10is made from resin. The support member10includes the rotor accommodating portion12and a flange portion11.

The rotor accommodating portion12is located radially inside the stator assembly75. That is, the rotor accommodating portion12is located radially inside the stator70. The rotor accommodating portion12has a cylindrical shape that surrounds the central axis J and opens downward. The rotor accommodating portion12accommodates the rotor50inside. The rotor accommodating portion12includes a lid portion12athat covers the rotor50from above, and a tubular portion12bthat extends downward from the lid portion12a.

The lid portion12ahas a disk shape with the central axis J at the center. The lid portion12acovers the rotor50from the upper side (the second side in the axial direction). A holding portion12cis provided at the center of the lid portion12awhen viewed from the axial direction. The holding portion12cis a portion that holds an end portion on the upper side of the fixed shaft40. The holding portion12cprotrudes more downward than other portions of the lid portion12a.

The tubular portion12bextends downward from a radially outer peripheral edge portion of the lid portion12aand is connected to a radially inner peripheral edge portion of the flange portion11. The tubular portion12bis located between the rotor50and the stator assembly75in the radial direction. That is, the tubular portion12bis located between the rotor50and the stator70in the radial direction. The tubular portion12bopens downward.

According to the present embodiment, the rotor accommodating portion12accommodates the rotor50inside. Further, the rotor accommodating portion12includes the lid portion12athat covers the rotor50from above, and the tubular portion12bthat surrounds the rotor50and opens downward. In this manner, the rotor accommodating portion12can seal the rotor50and the stator70with a space between them while securing a structure for connecting the pump unit60to the lower side of the rotor50, and it is possible to prevent liquid (water) sent by the pump unit60from coming into contact with the stator70.

The flange portion11has an annular shape surrounding the central axis J. The flange portion11extends radially outward from an end portion on the lower side (the first side in the axial direction) of the rotor accommodating portion12. The flange portion11is located on the lower side of the stator70. A surface (third contact surface10fto be described later) facing the lower side of the flange portion11is welded to the pump cover20.

An outer peripheral surface of the flange portion11is covered with the holding tubular portion31of the resin housing30. That is, the holding tubular portion31comes into contact with an outer peripheral surface of the flange portion11at least at a part of an inner peripheral surface. In the present embodiment, the support member10is embedded in the resin housing30together with the stator assembly75.

The flange portion11is embedded in the resin housing30at a part of an upper surface and an outer peripheral surface, and is exposed from the resin housing30at a lower surface. The resin housing30has a stepped surface32ain a portion in which an upper surface of the flange portion11is embedded. That is, the resin housing30has the stepped surface32ain contact with an upper surface (surface facing the second side in the axial direction) of the flange portion11. The resin housing30axially supports the flange portion11on the stepped surface32a.

As illustrated inFIG.1, a plurality of protruding portions11earranged along the circumferential direction are provided on an outer peripheral surface of the flange portion11. On an inner peripheral surface of the holding tubular portion31, a plurality of recessed portions31einto which the protruding portions11eare inserted are provided. The recessed portion31eis molded as molten resin surrounds an outer peripheral surface of the flange portion and fills the space between each protruding portion11eduring molding of the resin housing30. For this reason, the protruding portion11eand the recessed portion31eare in close contact with each other.

A positioning rib11dis provided on a lower surface (surface facing the first side in the axial direction) of the flange portion11. The positioning rib11dprotrudes downward from a lower surface of the flange portion11. The positioning rib11dextends along the circumferential direction around the central axis J. An outer peripheral surface of the positioning rib11dfacing radially outward is fitted to an inner peripheral surface of the pump cover20. The positioning rib11drelatively axially aligns the pump cover20and the support member10. A slight gap may be provided between an outer peripheral surface of the positioning rib11dand an inner peripheral surface of the pump cover20. In this case, the pump cover20and the support member10are axially aligned while allowing an assembly error within a range of the gap.

As illustrated inFIG.2, the fixed shaft40extends in the axial direction. The fixed shaft40includes a shaft main body portion41having a cylindrical shape extending in the axial direction about the central axis J, and a holding member42arranged on the second side in the axial direction of the shaft main body portion41. The shaft main body portion41and the holding member42are made from a metal material having excellent thermal conductivity.

A screw hole41his provided in a lower end surface of the shaft main body portion41. The screw hole41hextends in the axial direction around the central axis J. A retaining screw69is inserted into the screw hole41h. The retaining screw69prevents the pump unit60from being detached downward.

A retaining recessed portion61is provided at the center of the pump unit60. The retaining recessed portion61opens downward. The retaining recessed portion61has a retaining surface61pfacing downward as a bottom surface. The retaining screw69described above is arranged inside the retaining recessed portion61. A seat surface of the head of the retaining screw69and the retaining surface61pof the retaining recessed portion61of the pump unit60face each other in the axial direction with a washer68interposed between them.

A lower end surface of the shaft main body portion41, the retaining screw69, and the washer68are exposed in a flow path of fluid pressure-fed by the pump unit60. Therefore, the fixed shaft40, the retaining screw69, and the washer68are brought into contact with water (liquid) flowing into the pump unit60and are water-cooled. For this reason, heat transferred from the circuit board80to the fixed shaft40can be released to water to efficiently cool the circuit board80.

As illustrated inFIG.5, the holding member42is arranged on the upper side (the second side in the axial direction) of the shaft main body portion41. The holding member42includes a holding member main body42band a holding member flange portion (flange portion)42fextending radially outward from the holding member main body42b. The holding member main body42bis provided with a holding hole portion42hthat opens downward. An upper end portion of the shaft main body portion41is fitted into the holding hole portion42h. In this manner, the shaft main body portion41is fixed to the holding member42.

According to the present embodiment, the fixed shaft40includes the shaft main body portion41and the holding member42fixed to each other. For this reason, the fixed shaft40can be manufactured by assembling the shaft main body portion41and the holding member42which are separately manufactured, and the fixed shaft40can be manufactured at low cost.

The holding member42is embedded in the lid portion12aof the support member10by insert molding.

More specifically, the holding member flange portion42fof the holding member42is embedded in the holding portion12cof the lid portion12a. In this manner, the fixed shaft40is supported by the lid portion12a. According to the present embodiment, since the holding member flange portion42fis embedded in the holding portion12c, the holding member flange portion42fis caught by the holding portion12cby a large area in the axial direction. In this manner, it is possible to prevent the holding member flange portion42ffrom coming out of the holding portion12cdownward.

The holding member flange portion42fextends radially outward with respect to the shaft main body portion41. The holding member flange portion42fis subjected to surface treatment, so that adhesion to a resin material constituting the holding portion12cis enhanced. In this manner, entry of moisture into an interface between the holding member42and the holding portion12cis suppressed. Therefore, moisture does not reach the upper side of the lid portion12afrom the inside of the rotor accommodating portion12.

The holding member42has an exposed portion42aexposed to the upper side (the second side in the axial direction) with respect to the lid portion12a. That is, the fixed shaft40has the exposed portion42a. The exposed portion42aextends along a plane that is an upper surface of the holding member main body42band orthogonal to the central axis J. The exposed portion42aextends along a plane orthogonal to the central axis J. The exposed portion42afaces the circuit board80located above the lid portion12a.

A heat conductive material9is sandwiched between the exposed portion42aand the circuit board80. The heat conductive material9of the present embodiment is a sheet-like heat dissipation sheet. As a material of the heat conductive material9, a silicon-based material or the like is used. The heat conductive material9may be heat dissipation grease or heat dissipation gel.

The heat conductive material9is in contact with the exposed portion42a. The heat conductive material9is in contact with the lower surface81bof the substrate main body81of the circuit board80. The heat conductive material9transfers heat of the circuit board80to the fixed shaft40.

According to the present embodiment, the heat conductive material9transfers heat generated in the circuit board80to the fixed shaft40via the heat conductive material9. The fixed shaft40has a sufficiently large heat capacity as compared with the heat generating element82and the substrate main body81. Further, the fixed shaft40is cooled in contact with water (liquid) discharged by the pump unit60. For this reason, according to the present embodiment, the circuit board80can be effectively cooled, and reliability of operation of the circuit board80can be enhanced.

According to the present embodiment, the circuit board80is cooled using the fixed shaft40provided inside the pump1. For this reason, the entire pump1can be downsized in the axial direction as compared with a case where a heat sink is also used on the upper side of the circuit board80. In addition, as compared with the case of using a heat sink, a seal structure around the heat sink can be omitted, and manufacturing cost can be reduced.

In the present embodiment, the heat generating element82, the heat conductive material9, and the exposed portion42aoverlap each other when viewed from the axial direction. For this reason, heat generated by the heat generating element82can be transferred to the exposed portion42aof the fixed shaft40via the substrate main body81and the heat conductive material9in a shortest distance, and the heat generating element82can be efficiently cooled by the fixed shaft40.

In the present embodiment, the case where the heat generating element82is mounted on the upper surface81aof the substrate main body81is described. In this case, heat of the heat generating element82is transferred to the heat conductive material9via the circuit board. On the other hand, as illustrated inFIG.8as a variation, the heat generating element82may be mounted on the lower surface81b(surface on the first side in the axial direction) of the substrate main body81. In this variation, a heat conductive material109is in direct contact with the heat generating element. For this reason, heat of the heat generating element can be directly transferred to the heat conductive material109, and cooling efficiency of the heat generating element82can be enhanced.

As illustrated inFIG.2, the rotor50is accommodated inside the rotor accommodating portion12. The rotor50is rotatable about the central axis J. The rotor50includes a rotor core51, a magnet52, a first covering portion54, and a resin portion53.

The rotor core51has an annular shape surrounding the central axis J. The fixed shaft40axially passes through the radially inner side of the rotor core51. The magnet52is fixed to the rotor core51. In the present embodiment, the magnet52is arranged on an outer peripheral surface of the rotor core51. For example, a plurality of magnets52are provided at intervals in the circumferential direction. The first covering portion54fixes the rotor core51and the plurality of magnets52to each other. The first covering portion54, the rotor core51, and the magnet52constitute a rotor assembly55.

The resin portion53has a cylindrical shape surrounding the central axis J and extending in the axial direction. The fixed shaft40passes through the radially inner side of the resin portion53in the axial direction. The fixed shaft40is inserted radially inside the resin portion53. The fixed shaft40rotatably supports the rotor50by supporting an inner peripheral surface of the resin portion53.

The resin portion53includes a second covering portion53athat embeds and holds the rotor assembly55, and an extending portion53bextending downward from the second covering portion53a. The second covering portion53ahas a portion positioned between the fixed shaft40and the rotor core51in the radial direction. An end portion on the lower side of the extending portion53bprotrudes further downward than the rotor accommodating portion12. The retaining recessed portion61is provided in a lower end portion of the extending portion53b. As described above, the retaining screw69that suppresses detachment of the rotor50and the pump unit60is arranged inside the retaining recessed portion61.

An outer peripheral surface of the resin portion53is an outer peripheral surface of the rotor50. The outer peripheral surface of the resin portion53is located radially inward away from an inner peripheral surface of the rotor accommodating portion12. An outer peripheral surface of the second covering portion53afaces an inner peripheral surface of the rotor accommodating portion12with a slight gap interposed between them.

The pump unit60is connected to the lower side (the first side in the axial direction) of the rotor50. In the present embodiment, the pump unit60is an impeller. The pump unit60is made from resin.

The pump unit60includes an impeller main body portion62connected to a lower end portion of the extending portion53bof the rotor50. The resin portion53and the impeller main body portion62are a part of the same single member. A portion made from resin including the resin portion53and the impeller main body portion62is formed by, for example, insert molding using the rotor assembly55as an insert member.

The impeller main body portion62includes a base plate portion62a, a shroud plate portion62b, a plurality of blade portions62c, and a cylindrical portion62d.

The base plate portion62aand the shroud plate portion62bare circular when viewed from the axial direction. The base plate portion62aexpands radially outward from an outer peripheral surface of the extending portion53b. The shroud plate portion62bexpands radially outward along a plate surface of the base plate portion62abelow the base plate portion62a.

The cylindrical portion62dextends along the axial direction about the central axis J. The cylindrical portion62dsurrounds the extending portion53bfrom the radially outer side. The inside of the cylindrical portion62dis continuous with a space between the base plate portion62aand the shroud plate portion62b. The blade portion62cconnects the base plate portion62aand the shroud plate portion62b. The blade portion62cextends along the radial direction. When the pump unit60rotates, a plurality of blade portions62cfeed liquid between the blade portions62cradially outward.

The pump unit60has a suction port64for sucking water (liquid) and a discharge port65for discharging water (liquid). The suction port64faces downward and faces the inlet pipe26in the axial direction. On the other hand, the discharge port65faces radially outside and faces the outlet pipe27(seeFIG.1) in the radial direction.

The suction port64is provided in an end portion on the lower side of the cylindrical portion62d. The suction port64opens downward. Meanwhile, the discharge port65is provided between the base plate portion62aand the shroud plate portion62bin the axial direction. The discharge port65opens radially outward. The pump unit60is rotated about the central axis J by the rotor50to suck water from the suction port64to the inside and discharge the water from the discharge port65to feed the water. The water sent by the pump unit60also flows into the rotor accommodating portion12.

As illustrated inFIG.3, the stator assembly75includes a stator core71having an annular shape, a plurality of coils73mounted on the stator core71, a plurality of insulators72interposed between the stator core71and the plurality of coils73, and a stator cover90. In the stator70, the stator core71, the plurality of coils73, and the plurality of insulators72constitute the stator70. That is, the stator assembly75includes the stator70and the stator cover90.

The stator70is located radially outside the rotor50and surrounds the rotor50. The stator70has an annular shape surrounding the rotor accommodating portion12and the rotor50on the radially outer side of the rotor accommodating portion12. The stator70includes the stator core71, the insulator72attached to the stator core71, and the plurality of coils73attached to the stator core71with the insulator72interposed between them.

The stator core71is located radially outside the rotor accommodating portion12and surrounds the rotor core51. The stator core71has a core back71ahaving an annular shape surrounding the rotor core51and a plurality of teeth71bextending radially inward from the core back71a. Although not illustrated, the plurality of teeth71bare arranged side by side along the circumferential direction.

An end portion on the radially inner side of the plurality of teeth71bfaces an outer peripheral surface of the tubular portion12bin the rotor accommodating portion12with a slight gap interposed between them. That is, in the present embodiment, the stator70is arranged in a non-contact state with the outer peripheral surface of the tubular portion12b.

As illustrated inFIG.4, the coil73is configured by winding the coil wire73aaround the teeth71b. The insulator72is interposed between the coil73and the teeth71b. An end portion of the coil wire73aextends upward from the coil73. The extended coil wire73ais connected to the circuit board80. The number of the coils73provided in the stator70is the same as that of the teeth71b.

As illustrated inFIG.3, the insulator72is attached to the teeth71b. The insulator72covers an outer peripheral surface of the teeth71b. The insulator72of the present embodiment can be divided in the vertical direction. The insulator72is assembled to the teeth71bfrom the vertical direction. The insulator72of the present embodiment is attached to each of the teeth71b. The number of the insulators72provided on the stator70is the same as that of the teeth71b.

The insulator72includes a surrounding portion72darranged between the coil73and the teeth71b, an outer wall portion72blocated radially outside the coil73, and an inner wall portion72clocated radially inside the coil73. The surrounding portion72dhas a rectangular tubular shape that covers an outer peripheral surface of the teeth71b. The outer wall portion72band the inner wall portion72csandwich the coil73from both sides in the radial direction.

FIG.7is a perspective view of the stator assembly75of the present embodiment.

As illustrated inFIGS.3and7, a stepped portion72ais provided on an outer surface of the outer wall portion72bfacing radially outward. The stepped portion72ais provided on each of the upper side and the lower side of the stator core71. The stepped portion72ais recessed radially inward with respect to an outer surface of the outer wall portion72b. The stepped portion72ais a stepped surface facing the stator core71side.

As illustrated inFIG.3, two of the stepped portions72aare provided in one of the insulators72. One of two of the stepped portions72ais located on the lower side of the stator core71, and the other is located on the upper side of the stator core71. As illustrated inFIG.7, the plurality of insulators72are arranged in the circumferential direction. Therefore, the plurality of stepped portions72aare arranged at equal intervals in the circumferential direction on the upper side and the lower side of the stator core71.

As illustrated inFIG.3, the stator cover90covers the plurality of coils73. As described above, the coil73is arranged between the outer wall portion72band the inner wall portion72cof the insulator72. Further, the coil73is exposed to the upper side and the lower side with respect to the insulator72.

The stator cover90is arranged so as to extend between the outer wall portion72band the inner wall portion72cof the insulator72.

The stator cover90includes a first cover body91having an annular shape that covers the coil73from the lower side (the first side in the axial direction) and a second cover body92having an annular shape that covers the coil73from the upper side (the second side in the axial direction).

According to the present embodiment, since the stator cover90covers the coil73, the coil73can be protected from a molten resin material during molding of the resin housing30. Generally, an insulating film is provided on a surface of the coil wire73a. According to the present embodiment, it is possible to suppress damage to the insulating film of the coil wire73adue to heat and injection pressure of molten resin during molding of the resin housing30.

In the present embodiment, a gap G is provided between the stator cover90and the coil73. That is, according to the present embodiment, an air layer is provided between the resin housing30and the coil73, and heat of molten resin during molding is hardly transferred to the coil73. In this manner, damage to the insulation film of the coil wire73acan be more reliably suppressed.

In general, since the coil73is configured by winding the coil wire73a, an outer shape is hardly stabilized. According to the present embodiment, since the gap G is provided between the stator cover90and the coil73, the stator cover90can be assembled to the stator70without depending on a shape of the coil73.

Since an outer shape of the coil wire73ais exposed, a surface of the coil73has a complicated uneven shape. For this reason, in a case where a surface of the coil73is molded with the resin housing30, molten resin is less likely to wrap around a gap between the coil wires73a, and a sink mark or the like is likely to be generated inside the resin housing30. Further, since a surface of the coil73has a complicated uneven shape, it is difficult to control thickness of the resin housing30, and there is a problem that dimensional accuracy hardly stabilizes.

According to the present embodiment, the resin housing30does not cover a surface of the coil73but covers the stator cover90. That is, as mold resin does not need to cover a complicated uneven shape, a sink mark of the resin housing30can be suppressed, and dimensional accuracy can be stabilized.

According to the present embodiment, when the resin housing30is molded, a melted resin material covers surfaces of the stator cover90and the stator core71. In this manner, each part of the stator70can be sealed from the outside. Furthermore, the stator cover90is firmly fixed to the stator core71, and reliability of protection of the coil73by the stator cover90can be enhanced.

According to the present embodiment, the stator cover90includes a pair of the cover bodies91and92that cover the coil73from the lower side and the upper side, respectively. For this reason, the stator cover90can be easily assembled to the stator70. Further, the stator cover90can effectively cover an exposed portion of the coil73from the vertical direction by a pair of the cover bodies91and92.

As illustrated inFIG.7, each of the first cover body91and the second cover body92includes an annular main body portion93, an outer tubular portion95, an inner tubular portion96, a plurality of locking portions94a, and a plurality of sealing wall portions94f. The second cover body92further includes a plurality of columnar portions97and a terminal holding portion98. That is, the stator cover90includes the annular main body portion93, the outer tubular portion95, the inner tubular portion96, the locking portion94a, the sealing wall portion94f, the columnar portion97, and the terminal holding portion98.

The annular main body portion93has an annular shape around the central axis J. The annular main body portion93has a plurality of punched portions93a. The punched portion93aopens on a surface of the annular main body portion93facing the side opposite to the stator core71. The annular main body portion93of the first cover body91is located below the coil73, and the annular main body portion93of the second cover body92is located above the coil73.

As illustrated inFIG.4, the outer tubular portion95extends from an outer edge of the annular main body portion93to the stator core71side. Each of the outer tubular portion95and the inner tubular portion96has a cylindrical shape around the central axis J.

On the other hand, the inner tubular portion96extends from an inner edge of the annular main body portion93to the stator core71side. The outer tubular portion95and the inner tubular portion96of the first cover body91extend upward from the annular main body portion93. The outer tubular portion95and the inner tubular portion96of the second cover body92extend downward from the annular main body portion93. In description below, a tip portion of the outer tubular portion95or the inner tubular portion96means an end portion on the stator core71side in the axial direction.

The inner tubular portion96overlaps the inner wall portion72cof the insulator72when viewed from the axial direction. A tip portion of the inner tubular portion96is in contact with an end surface of the inner wall portion72cfacing the axial direction. The inner tubular portion96is located radially inside the coil73. An inner peripheral surface of the inner tubular portion96facing radially inward is continuous with an inner surface of the inner wall portion72cfacing radially inward. The inner peripheral surface of the inner tubular portion96and the inner side surface of the inner wall portion72care fitted to an outer peripheral surface of the tubular portion12bof the rotor accommodating portion12.

According to the present embodiment, an outer peripheral surface of the tubular portion12bof the support member10is fitted to the inner tubular portion96.

A gap between the inner tubular portion96and the tubular portion12bis sufficiently small to the extent that molten resin during molding does not pass through the gap. For this reason, it is possible to prevent the molten resin from flowing from the radially inner side of the inner tubular portion96to the coil73side (that is, the gap G) during molding of the resin housing30. As a result, it is possible to separate the coil73from the resin housing30to protect the coil73.

The outer tubular portion95is arranged radially outside the outer wall portion72bof the insulator72. The outer tubular portion95covers the vicinity of an upper end portion of an outer surface of the outer wall portion72bfrom the radially outer side. A tip portion of the outer tubular portion95faces an end face of the stator core71with a gap interposed between them.

As illustrated inFIG.3, the locking portion94aextends from the tip portion of the outer tubular portion95to the stator core71side. The locking portion94aof the first cover body91extends upward from an upper end portion of the outer tubular portion95. The locking portion94aof the second cover body92extends downward from a lower end portion of the outer tubular portion95.

The locking portion94aextends along the outer wall portion72bof the insulator72. A claw portion94aais provided in a tip portion of the locking portion94a. The claw portion94aais locked to the stepped portion72aprovided on an outer surface of the outer wall portion72b. That is, the cover bodies91and92have a plurality of claw portions94aaextending toward the stator core71side and locked to the insulator72.

As illustrated inFIG.7, the locking portions94aare arranged at equal intervals along the circumferential direction. The first cover body91and the second cover body92of the present embodiment are provided with the locking portions94aas many as the insulators72. Each of the locking portions94ais locked to one of the stepped portions72aprovided on the insulator72.

According to the present embodiment, the first cover body91and the second cover body92are assembled to the stator70from the vertical direction. The locking portion94afunctions as a snap-fit. For this reason, in an assembling process, the locking portion94ais elastically deformed radially outward until the claw portion94aareaches the stepped portion72ain the assembling process. A reinforcing rib94abis provided on an outer surface of the locking portion94a. The reinforcing rib94abreinforces the locking portion94awhile securing an elastic modulus of the locking portion94atoward the radial outside.

According to the present embodiment, the first cover body91and the second cover body92are locked and fixed to the stator70. This makes it possible to suppress positional displacement of the first cover body91and the second cover body92with respect to the stator70during molding of the resin housing30. Further, according to the present embodiment, since the first cover body91and the second cover body92are fixed to the stator70by a snap-fit, an assembly process of the stator assembly75can be simplified.

The sealing wall portion94fextends from a tip portion of the outer tubular portion95to the stator core71side. The sealing wall portion94fof the first cover body91extends upward from an upper end portion of the outer tubular portion95. The sealing wall portion94fof the second cover body92extends downward from a lower end portion of the outer tubular portion95.

The sealing wall portion94fhas a plate shape with the radial direction as the thickness direction. The sealing wall portion94fis arranged between the locking portions94aadjacent to each other in the circumferential direction. That is, the sealing wall portion94fis arranged between the claw portions94aain the circumferential direction. As described above, the insulators72are arranged in the circumferential direction. The outer wall portion72bof one of the insulators72extends in an arc shape along the circumferential direction when viewed from the axial direction. The outer wall portions72bof the insulators72arranged in the circumferential direction are continuous in the circumferential direction. In this manner, the outer wall portions72bof the plurality of insulators72form a cylindrical shape. The sealing wall portion94fcovers a gap between the outer wall portions72bof the insulators72arranged in the circumferential direction.

According to the present embodiment, the sealing wall portion94fcovers a space between the insulators72adjacent in the circumferential direction from the radial outside. For this reason, it is possible to prevent molten resin from flowing into the coil73side (that is, the gap G) from the gap between the insulators72during molding of the resin housing30. As a result, it is possible to separate the coil73from the resin housing30to protect the coil73.

When the resin housing30is molded, the first cover body91and the second cover body92are pressed against the stator core71side by resin pressure of molten resin. The locking portions94aof the first cover body91and the second cover body92have low strength so as to be smoothly elastically deformed at the time of locking. In the present embodiment, a tip surface of the sealing wall portion94ffacing the axial direction is in contact with the stator core71. For this reason, the sealing wall portion94fcan suppress damage to the locking portion94aby receiving a force caused by the resin pressure applied to the first cover body91and the second cover body92.

The columnar portion97extends upward from an upper surface of the annular main body portion93of the second cover body92. Three of the columnar portions97are provided on the second cover body92. Three of the columnar portions97are arranged along the circumferential direction.

A through hole (coil holding portion)97his opened on an upper surface of the columnar portion97. That is, the through hole97his provided in the second cover body92. In the present embodiment, two of the through holes97hare opened in one of the columnar portions97.

As illustrated inFIG.4, the through hole97hextends linearly in the axial direction. The through hole97hextends over the annular main body portion93and the columnar portion97in the second cover body92.

The coil wire73aextending upward from the coil73is inserted through the through hole97h. The through hole97hfunctions as a coil holding portion that holds the coil wire73a. That is, the stator cover90includes a coil holding portion (through hole97h) that holds the coil wire.

In the present embodiment, holding the coil wire73ameans supporting the coil wire73aalong the axial direction to maintain the posture and position of the coil wire73a. An inner peripheral surface of the through hole97hmay be in close contact with the coil wire73a. A hole diameter of the through hole97his preferably 1.5 times or less a wire diameter of the coil wire73a.

In the present embodiment, since the coil holding portion that holds the coil73is the through hole97h, the entire outer periphery of the coil wire73acan be surrounded, and the coil wire73acan be stably held. However, the coil holding portion may be a notch or the like provided so as to be recessed radially inward from an outer peripheral portion of the second cover body92.

The through hole97his provided with a tapered portion97twhose cross-sectional area decreases toward the upper side (the second side in the axial direction). In the present embodiment, the tapered portion97tis located in an end portion on the lower side of the through hole97h. A cross-sectional shape of the through hole97his circular over the entire length including the tapered portion97t. According to the present embodiment, when the stator cover90is assembled, an end portion of the coil wire73acan be easily guided to the inside of the through hole97h, and an assembly process of the stator assembly75can be facilitated.

In the present embodiment, the stator cover90holds the coil wire73adrawn out from the coil73in the through hole97hand connected to the circuit board80. Accordingly, the stator cover90can position the coil wire73aand facilitate a connecting process of the coil wire73ato the circuit board80.

In the present embodiment, the through hole97hconnects a space in which the coil73is accommodated and a space in which the circuit board80is accommodated in the case2. For this reason, during molding of the resin housing30, molten resin does not come into contact with the coil wire73adrawn out from the coil73. That is, the stator cover90can protect the drawn coil wire73afrom the molten resin in the through hole97h.

The through hole97hof the present embodiment overlaps the first through hole81hof the circuit board80when viewed from the axial direction. For this reason, the coil wire73aextending upward from the through hole97hcan be smoothly inserted into the first through hole81hof the circuit board80. Further, since the coil wire73ais held by the through hole97h, the coil wire73acan be stably soldered to the first through hole81h, and reliability of connection between the coil wire73aand the circuit board80can be enhanced.

The through hole97hof the present embodiment extends in the axial direction inside the columnar portion97. The columnar portion97extends along the axial direction and penetrates the resin housing30in the axial direction. For this reason, the through hole97hcan be secured long, and reliability of holding of the coil wire73aby the through hole97hcan be enhanced.

An upper end surface (tip surface)97aof the columnar portion97is exposed to the upper side with respect to the resin housing30.

The upper end surface97ais covered with a mold during molding of the resin housing30. The upper end surface97aof the columnar portion97faces the circuit board80, and an opening of the through hole97his provided. For this reason, during molding of the resin housing30, molten resin does not enter the inside of the through hole97h, and the coil wire73acan be more reliably protected.

As illustrated inFIG.7, the terminal holding portion98is arranged on an upper surface of the annular main body portion93of the second cover body92. The terminal holding portion98includes a radially extending portion98aextending radially outward with respect to the second cover body92and an upper protruding portion98bextending upward from an end portion on the radially outer side of the radially extending portion98a. The terminal holding portion98holds a plurality (three in the present embodiment) of the terminals8embedded in the terminal holding portion98. The second cover body92is formed by insert molding in which the terminal8is inserted.

The terminal8includes a base portion8cextending along the radial direction, a first end portion8aextending upward from an end portion on the radially inner side of the base portion8c, and a second end portion8bextending upward from an end portion on the radially outer side of the base portion8c. The base portion8cextends along the radial direction inside the radially extending portion98aof the terminal holding portion98. The first end portion8aprotrudes upward from the radially extending portion98a. The second end portion8bextends upward along the upper protruding portion98band protrudes upward from an upper end surface of the upper protruding portion98b.

As illustrated inFIG.2, the first end portion8aof the terminal8passes through the inside of the resin housing30and protrudes upward from the housing upper surface30g. The first end portion8ais inserted into the second through hole81kof the circuit board80and connected to the circuit board80by soldering.

The second end portion8bof the terminal8protrudes upward in the connector portion39of the resin housing30. The connector portion39exposes the second end portion8bof the terminal8and surrounds the periphery. The second end portion8bis connected to the external device7connected to the connector portion39. The external device7supplies power to the circuit board80via the terminal8. Further, the circuit board80supplies power from the coil wire73ato the coil73.

According to the present embodiment, since the stator cover90includes the terminal holding portion98, the terminal8can be held by the stator cover90in advance. For this reason, during formation of the resin housing30, the terminal8can be easily embedded in the resin housing30, and a manufacturing process can be simplified.

The pump cover20constitutes a lower end portion of the case2. The pump cover20is located below (on the first side in the axial direction of) the motor3, the resin housing30, and the support member10. The pump cover20covers the pump unit60. The pump cover20includes a pump surrounding portion22, an upper end tubular portion21, the inlet pipe26, and the outlet pipe27(seeFIG.1). The pump surrounding portion22covers the pump unit60from radially outside and below.

A flow path through which water (liquid) flows is provided inside the pump surrounding portion22. The upper end tubular portion21extends upward from an upper end portion of the pump surrounding portion22. The upper end tubular portion21has a tubular shape about the central axis J. The upper end tubular portion21surrounds an outer peripheral surface of the holding tubular portion31of the resin housing30.

As illustrated inFIG.1, the inlet pipe26extends downward from a lower end portion of the pump surrounding portion22. Further, the outlet pipe27extends radially outward from an outer peripheral portion of the pump surrounding portion22. The inlet pipe26and the outlet pipe27are connected to an internal space of the pump surrounding portion22.

The pump cover20is joined to the resin housing30and the support member10by welding. Hereinafter, a joining configuration of the pump cover20, the resin housing30, and the support member10will be described. The pump cover20is welded to the resin housing30and the support member10by spin welding.

As illustrated inFIG.6, the pump cover20has a first contact surface20fhaving an annular shape. The first contact surface20fhas a main region20afacing the upper side (the second side in the axial direction) and a subregion20bfacing the radial inside. The main region20ais an upper end surface of the pump surrounding portion22. The subregion20bis located on an inner peripheral surface of the upper end tubular portion21. The main region20aand the subregion20bare connected to be orthogonal to each other. Both the main region20aand the subregion20bextend annularly along the circumferential direction around the central axis J.

The resin housing30has a second contact surface30fand a fourth contact surface30ein a lower end portion. The second contact surface30fis a flat surface facing the lower side (the second side in the axial direction). On the other hand, the fourth contact surface30eis a curved surface facing radially outward. The second contact surface30fand the fourth contact surface30eextend annularly along the circumferential direction around the central axis J. The second contact surface30fis a lower end surface of the holding tubular portion31. On the other hand, the fourth contact surface30eis located on an outer peripheral surface of the holding tubular portion31. That is, the second contact surface30fand the fourth contact surface30eare provided on the holding tubular portion31. The second contact surface30fis in contact with and welded to the main region20aof the first contact surface20fin the vertical direction. On the other hand, the fourth contact surface30eis in contact with and welded to the subregion20bof the first contact surface20fin the radial direction.

The support member10has the third contact surface10fin a lower end portion. The third contact surface10fis a flat surface facing the lower side (the second side in the axial direction). The third contact surface10fextends annularly along the circumferential direction around the central axis J. The third contact surface10fis a lower end surface of the flange portion11. That is, the third contact surface10fis provided on the flange portion11. The third contact surface10fis in contact with and welded to the main region of the first contact surface20fin the vertical direction. The third contact surface10fis arranged adjacent to the radially inner side of the second contact surface30f. The second contact surface30fand the third contact surface10fare arranged on the same plane orthogonal to the central axis J.

According to the present embodiment, the first contact surface20fof the pump cover20is welded to the second contact surface30fof the resin housing30and the third contact surface10fof the support member10. Since the first contact surface20fis welded to the second contact surface30f, the waterproof region A1and the flow path region A2inside the case2can be sealed with respect to the outside of the case2. Further, since the first contact surface20fis welded to the third contact surface10f, the waterproof region A1and the flow path region A2can be sealed from each other inside the case2. In this manner, it is possible to realize sealing of the pump1without using a sealing member such as an O-ring, and it is possible to reduce the number of parts and manufacture the pump1at low cost and with high reliability.

In addition, according to the present embodiment, the resin housing30and the support member10are welded to one contact surface (the first contact surface20f) of the pump cover20. For this reason, in one welding process, two members, the resin housing30and the support member10, can be joined to the pump cover20, and the welding process can be simplified.

According to the present embodiment, since the first contact surface20fis annular, a welded portion can be arranged in an annular shape, and an inner region and an outer region of the welded portion can be sealed from each other. In addition, since the first contact surface20fis annular, it is possible to employ spin welding in which the pump cover20is rotated with respect to the resin housing30and the support member10to weld contact surfaces to each other, and work efficiency of the welding process can be enhanced.

In the present embodiment, the case where the pump cover20, the resin housing30, and the support member10are joined by spin welding is exemplified, but other welding means may be employed. As an example, the pump cover20, the resin housing30, and the support member10may be welded by ultrasonic welding, laser welding, or the like.

According to the present embodiment, the first contact surface20ffaces upward, and the second contact surface30fand the third contact surface10fwelded to the first contact surface20fface downward. For this reason, welding can be performed while stress is applied in the axial direction to a contact portion between the first contact surface20fand the second contact surface30fand the third contact surface10f, and welding efficiency in the case of employing spin welding can be enhanced.

As described above, the support member10is molded with the resin housing30. For this reason, the support member10and the resin housing30are in close contact with each other, but are not joined together. Therefore, a minute gap is provided between the support member10and the resin housing30.

In the present embodiment, the second contact surface30fof the resin housing30and the third contact surface10fof the support member10are arranged adjacent to each other in the radial direction. For this reason, a part of a resin material melted in a welding process enters a minute gap between the support member10and the resin housing30and is solidified. In this manner, sealing between the support member10and the resin housing30becomes possible, and a more reliable sealing structure can be realized.

As described above with reference toFIG.1, the protruding portion11eprovided on an outer peripheral surface of the flange portion11is fitted into the recessed portion31eof the holding tubular portion31. According to the present embodiment, the protruding portion11eand the recessed portion31efunction as a rotation stopper between the support member10and the resin housing30. This makes it possible to suppress relative rotation of the resin housing30and the support member10in a welding process by spin welding.

According to the present embodiment, the protruding portion11eand the recessed portion31eare arranged along the circumferential direction and are fitted to each other. For this reason, a minute gap between the support member10and the resin housing30extends in a wave shape along the circumferential direction. A resin material melted by the spin welding spreads in the circumferential direction at an interfaces between the first contact surface20fand the second contact surface30fand the third contact surface10fby rotation during the spin welding. According to the present embodiment, the gap between the support member10and the resin housing30is arranged in a wave shape along the circumferential direction, so that a resin material that melts during spin welding can be caused to effectively enter the gap and solidified, and a highly reliable sealing structure can be realized.

As illustrated inFIG.6, the pump cover20of the present embodiment is welded to the fourth contact surface of the resin housing30in the subregion20bof the first contact surface20f. According to the present embodiment, it is possible to secure a wide area of a welding surface and further enhance reliability of sealing. In addition, the welded portion can have a complicated labyrinth structure, so that it is possible to enhance reliability of sealing and rigidity of the welded portion.

In the present embodiment, the pump cover20has an upper end surface21alocated at an upper end of the upper end tubular portion21. The upper end surface21ais an annular flat surface facing the upper side (the second side in the axial direction). A stepped portion30drecessed downward and radially inward is provided in a lower end portion of the outer peripheral surface30aof the resin housing30. The upper end tubular portion21of the pump cover20is fitted into the stepped portion30d.

The stepped portion30dhas a facing surface32bfacing downward. That is, the resin housing30has the facing surface32b. The facing surface32bfaces the upper end surface21aof the upper end tubular portion21with a gap interposed between them. According to the present embodiment, since a gap is provided between the facing surface32band the upper end surface21a, even when a part of the first contact surface20fand a part of the second contact surface30fis melted in a welding process and the pump cover20and the resin housing30relatively approach each other in the axial direction, interference between the facing surface32band the upper end surface21acan be suppressed.

In the present embodiment, the resin housing30, the pump cover20, and the support member10welded to each other are preferably made from the same kind of resin material. Similarly, the resin housing30and the substrate cover28which are welded to each other are preferably made from the same kind of resin material. By forming members to be welded from the same kind of resin material, it is possible to realize firm welding, thermal distortion is less likely to occur even after welding, and it is possible to suppress occurrence of damage to a welded portion.

Although various embodiments of the present invention are described above, configurations in the embodiments and a combination of the configurations are examples, and thus addition, omission, replacement of a configuration, and other modifications can be made within a range not deviating from the gist of the present invention. Further, the present invention is not to be limited by the embodiments.

For example, use of a pump to which the present invention is applied is not particularly limited. The pump may be mounted on any device. The pump may be mounted on a vehicle, for example. The pump may be a pump that sends any fluid. The pump may be an oil pump that sends oil. The configurations described in the present description can be appropriately combined within a range not contradictory to one another.