JP2021005917A - Electrically-driven water pump and manufacturing method of electrically-driven water pump - Google Patents

Abstract

To suppress an increase in the number of components.SOLUTION: An electrically-driven water pump 10 comprises; a stator 18; a rotor 16 arranged oppositely to the stator 18 in an axial direction; an impeller 14 which is arranged so that it can integrally rotate with the rotor 16; and a pump case 12 where liquid flowing in from an inlet pipe 12A flows out from an outlet pipe 12B by rotation of the impeller 14. The electrically-driven water pump 10 comprises: a motor housing 20 which supports the stator 18 and to which the pump case 12 is attached; and a partition member 22. The partition member 22 comprises a first partition part 22A and a second partition part 22B for partitioning a space in the pump case 12 and a portion where the stator 18 is fixed in the motor housing 20; and a first fixing part 22C and a second fixing part 22D embedded inside the motor housing 20.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electric water pump and a method for manufacturing an electric water pump.

Patent Document 1 below discloses an electric water pump including an axial gap type motor in which a stator and a rotor are arranged so as to face each other in the axial direction. This electric water pump includes a resin molded body that supports the stator core of the stator and the like, and a pump cover in which the rotor is arranged therein. Further, a partition wall for separating these members is provided between the resin molded body and the pump cover. Then, with the partition wall arranged between the resin molded body and the pump cover and the O-ring arranged between the partition wall and the pump cover, the screw inserted into the outer peripheral portion of the pump cover is inserted into the resin molded body. Screw on the outer circumference of. As a result, the resin molded body and the pump cover are integrated in a state where the partition wall is sandwiched between the pump cover and the resin molded body.

Japanese Patent No. 5494470

However, in a configuration in which the partition wall is sandwiched between the pump cover and the resin molded body as in the electric water pump described in Patent Document 1, O-rings, screws, etc. are required, and the number of component parts is increased. It is difficult to control the increase.

In consideration of the above facts, an object of the present invention is to obtain an electric water pump and a method for manufacturing an electric water pump capable of suppressing an increase in the number of component parts.

The electric water pump (10) for achieving the above object is arranged to face the stator (18) that generates a rotating magnetic field in the axial direction, and the stator rotates by generating a rotating magnetic field. It has a rotor (16), an impeller (14) that can rotate integrally with the rotor, an inlet pipe (12A) into which the liquid flows in, and an outlet pipe (12B) from which the liquid flows out, and the impeller is arranged inside. A pump case (12) in which the liquid flowing in from the inlet pipe flows out from the outlet pipe by rotating the impeller, a housing (20) in which the stator is supported and the pump case is attached, and the above. A partition member (22) having a partition portion (22A, 22B) that separates a space inside the pump case from a portion of the housing to which the stator is fixed, and a fixing portion (22C, 22D) embedded inside the housing. ) And.
Further, in the method of manufacturing an electric water pump, a mold (30) in which the material forming the housing is injected inside and the material contracted when the material injected into the mold is cooled. A partition member setting step of setting the partition member inside the mold by using the partition member having the fixing portion whose surface is directed in a direction, and an injection step of injecting the material into the mold. It has a cooling step of forming the housing in which the fixing portion is embedded by cooling the material injected into the inside of the mold.

According to the above-mentioned electric water pump and electric water pump, it is possible to suppress an increase in the number of component parts.

It is sectional drawing which shows the cross section which cut the electric water pump of this embodiment along the axial direction. It is a partial perspective sectional view which shows the electric water pump of this embodiment. It is sectional drawing which shows the cross section which cut | cut the electric water pump of this embodiment along an axial direction, and shows the part where the stator and the partition member were provided enlarged. It is an enlarged cross-sectional view corresponding to FIG. 3 which shows the stator and the partition member set in the mold. FIG. 5 is an enlarged cross-sectional view corresponding to FIG. 3 showing an example in which an adhesive member is provided between the partition member and the housing. FIG. 5 is an enlarged cross-sectional view corresponding to FIG. 3 showing an example in which a cushioning member is provided between the partition member and the housing. It is an enlarged sectional view which shows the fixed part of another form of a partition member in an enlarged manner. It is an enlarged sectional view which shows the fixed part of another form of a partition member in an enlarged manner. It is an enlarged sectional view which shows the fixed part of another form of a partition member in an enlarged manner. It is an enlarged sectional view which shows the fixed part of another form of a partition member in an enlarged manner. It is sectional drawing corresponding to FIG. 1 which shows the electric water pump of another form. It is a partial perspective sectional view corresponding to FIG. 2 which shows the electric water pump of another form.

The electric water pump 10 according to the embodiment will be described with reference to FIGS. 1 to 3. The arrow Z direction, arrow R direction, and arrow C direction, which are appropriately shown in the drawing, indicate one side of the rotor 16 and the impeller 14 described later in the rotation axis direction, the outside in the rotation radial direction, and one side in the rotation circumferential direction, respectively. .. In addition, when simply indicating the axial direction, the radial direction, and the circumferential direction, unless otherwise specified, the rotation axis direction, the rotation radial direction, and the rotation circumferential direction of the rotor 16 and the impeller 14 are indicated.

As shown in FIGS. 1 and 2, the electric water pump 10 of the present embodiment includes an inlet pipe 12A as an inflow portion into which a liquid such as cooling water flows in and an outlet pipe 12B as an outflow portion through which the liquid flows out. The pump case 12 and the rotor 16 integrally formed with the impeller 14 arranged in the pump case 12 are provided. Further, the electric water pump 10 includes a stator 18 that rotates the rotor 16 by generating a magnetic field, and a motor housing 20 as a housing in which the stator 18 is fixed and the rotor 16 is supported. Further, the electric water pump 10 includes a partition member 22 that separates a space in the pump case 12, which will be described later, from a portion of the motor housing 20 to which the stator 18 is fixed.

(Configuration of pump case 12)
The pump case 12 includes a spiral portion 12C formed by using an insulating member such as a resin material and formed in a substantially cochlear shape. The inlet pipe 12A projects from the axial center side of the spiral portion 12C toward one side in the axial direction. Further, the outlet pipe 12B protrudes outward in the radial direction from the outer peripheral portion of the spiral portion 12C. At the boundary between the spiral portion 12C and the inlet pipe 12A, a rotating shaft end engaging portion 12D with which one end of the rotating shaft 23 on one side in the axial direction is engaged is provided.

The space between the inside of the spiral portion 12C of the pump case 12 described above and the motor housing 20 described later is a pump chamber 24 in which the impeller 14 and the rotor 16 described later are arranged. Then, as the impeller 14 rotates in the pump chamber 24, the cooling water that has flowed from the inlet pipe 12A into the inside of the spiral portion 12C (pump chamber 24) is pumped from the outlet pipe 12B.

(Structure of motor housing 20)
The motor housing 20 is formed in a bottomed cylindrical shape in which one side in the axial direction is open by using an insulating member such as a resin material. Specifically, the motor housing 20 includes a bottom wall portion 20A formed in a disk shape. Further, the motor housing 20 includes a thick-walled cylindrical rotary shaft support portion 20B that projects from the central portion in the radial direction of the bottom wall portion 20A toward one side in the axial direction. The other side of the rotary shaft 23 of the rotor 16 in the axial direction is supported by the shaft core portion (central portion in the radial direction) of the rotary shaft support portion 20B.

Further, the motor housing 20 includes an annular outer peripheral wall portion 20C that projects from the outside in the radial direction to one side in the axial direction in the bottom wall portion 20A. The pump case 12 described above is joined to the outer peripheral side of the outer peripheral wall portion 20C on one side in the axial direction by heat welding or the like. Further, the motor housing 20 includes a fixed flange portion 20D extending radially outward from an intermediate portion in the axial direction of the outer peripheral wall portion 20C. The electric water pump 10 is mounted (supported) on the mounting target by screwing the bolt inserted through the fixed flange portion 20D into the mounting target.

(Structure of stator 18)
The stator 18 is composed of a stator core 18A formed in an annular shape and a conductive winding 18B (coil 18C) wound around the stator core 18A as main elements. The side of the stator 18 opposite to the magnet 26, which will be described later, is embedded in the motor housing 20. As a result, the stator 18 is supported (fixed) on the bottom wall portion 20A side between the rotating shaft support portion 20B and the outer peripheral wall portion 20C in the motor housing 20.

(Structure of rotor 16)
The rotor 16 is an impeller-integrated rotor configured by attaching an annular magnet 26 directly to the impeller 14 (the impeller 14 is directly attached to the annular magnet 26). Further, the rotor 16 of the present embodiment is an axial gap type rotor (rotor used for an axial gap type motor) in which the magnet 26 and the stator core 18A of the stator 18 are arranged so as to face each other in the axial direction. Specifically, the rotor 16 includes an impeller 14, a bearing member 28 fixed to the impeller 14, and a magnet 26 supported between the impeller 14 and the bearing member 28. Then, by inserting the rotating shaft 23 into the bearing member 28, the rotor 16 can rotate around the rotating shaft 23.

(Structure of partition member 22)
As shown in FIGS. 2 and 3, the partition member 22 is formed by pressing a steel plate material or the like. The partition member 22 includes a first partition portion 22A as a partition portion extending in the radial direction with the axial direction as the thickness direction. The first partition portion 22A is formed in an annular shape when viewed from the axial direction, and is arranged close to the surface of the stator core 18A on one side in the axial direction.

Further, the partition member 22 includes a second partition portion 22B as a partition portion that bends from the radially inner end of the first partition portion 22A toward the other side in the axial direction. The second partition portion 22B is formed in a tubular shape extending in the circumferential direction with the radial direction as the thickness direction, and is arranged close to the radial inner portion of the coil 18C of the stator 18.

Further, the partition member 22 includes a fixing portion that bends from the radial outer end of the first partition portion 22A toward the other side in the axial direction, and a first fixing portion 22C as an outer annular portion. The first fixing portion 22C is formed in a tubular shape extending in the circumferential direction with the radial direction (the direction perpendicular to the axial direction) as the thickness direction. Further, the first fixed portion 22C of the present embodiment is continuously connected in the circumferential direction. Further, the width dimension W1 in the axial direction of the first fixed portion 22C and a constant width dimension along the circumferential direction are set.

Further, the partition member 22 includes a fixing portion that bends inward in the radial direction from the end on the other side in the axial direction of the second partition portion 22B, and a second fixing portion 22D as an inner annular portion. The second fixing portion 22D is formed in a funnel shape that intersects the radial direction and the axial direction and extends in the circumferential direction with the direction orthogonal to the circumferential direction as the thickness direction, and the shaft extends inward in the radial direction. It is inclined to the other side in the direction. Further, the second fixed portion 22D of the present embodiment is continuously connected in the circumferential direction. Further, the width dimension W2 of the second fixing portion 22D in the thickness direction and the direction orthogonal to the circumferential direction is set to a constant width dimension along the circumferential direction.

Here, in the present embodiment, the radial outer ends of the first fixing portion 22C and the first partition portion 22A of the partition member 22 are embedded inside the outer peripheral wall portion 20C of the motor housing 20. There is. Further, in the present embodiment, the radial dimension T1 from the outer peripheral surface of the first fixed portion 22C embedded inside the outer peripheral wall portion 20C to the outer peripheral surface of the outer peripheral wall portion 20C (a part of the outer peripheral wall portion 20C). The thickness dimension T1) is thinner than the radial dimension T2 (thickness dimension T2 of a part of the outer peripheral wall portion 20C) from the inner peripheral surface of the first fixing portion 22C to the inner peripheral surface of the outer peripheral wall portion 20C. The radial position of the first fixing portion 22C is set so as to have dimensions. Further, in the cooling step of the "step of forming the motor housing 20" described later, the portion of the outer peripheral wall portion 20C of the motor housing 20 in which the first fixing portion 22C of the partition member 22 is embedded and the peripheral portion thereof are radially inside. Shrink toward. The contraction direction of the portion is indicated by an arrow F1. The outer peripheral surface of the first fixing portion 22C of the partition member 22 is directed in the direction opposite to the contraction direction F1 (the contraction direction F1 and the thickness direction of the first fixing portion 22C coincide with each other). As a result, after the formation of the motor housing 20 is completed, a force (force in the compression direction) for pressing the first fixed portion 22C from the outer peripheral wall portion 20C to the first fixed portion 22C in the thickness direction (inward in the radial direction). Is to be entered. In addition to this, no force (force in the shear direction) in the direction orthogonal to the thickness of the first fixed portion 22C is input from the outer peripheral wall portion 20C to the first fixed portion 22C, or a force in the direction is not input. Is almost never entered.

Further, in the present embodiment, the ends of the second fixing portion 22D and the second partition portion 22B of the partition member 22 on the other side in the axial direction are embedded in the rotating shaft support portion 20B side in the bottom wall portion 20A of the motor housing 20. It is supposed to be done. Further, the radially inner end of the second fixing portion 22D embedded in the bottom wall portion 20A and the radially outer end of the rotating shaft support portion 20B overlap in the axial direction (same in the radial direction). (Placed in position). Further, in the cooling step of the "step of forming the motor housing 20" described later, the portion of the bottom wall portion 20A of the motor housing 20 in which the second fixing portion 22D of the partition member 22 is embedded and the peripheral portion thereof are radially inside. And it contracts toward one side in the axial direction. The contraction direction of the portion is indicated by an arrow F2. The surface of the partition member 22 on the other side in the axial direction of the second fixing portion 22D is directed in the direction opposite to the contraction direction F2 (the contraction direction F2 and the thickness direction of the second fixing portion 22D coincide with each other). As a result, after the formation of the motor housing 20 is completed, a force (force in the compression direction) for pressing the second fixed portion 22D in the thickness direction is input from the bottom wall portion 20A to the second fixed portion 22D. It has become. In addition to this, no force (force in the shear direction) in the direction orthogonal to the thickness of the second fixed portion 22D is input from the bottom wall portion 20A to the second fixed portion 22D, or a force in the direction is not input. Is almost never entered.

In the present embodiment, the contraction directions F1 and F2 are obtained by CAE analysis, and the bending angle of the first fixing portion 22C with respect to the first partition portion 22A and the bending angle of the second fixing portion 22D with respect to the second partition portion 22B. Is set. Further, the contraction directions F1 and F2 may be obtained by trial production of the motor housing 20.

(Step of forming the motor housing 20)
Next, a step of forming the motor housing 20 which is a part of the manufacturing process of the electric water pump 10 of the present embodiment will be described.

As shown in FIG. 4, the motor housing 20 is formed by injecting a material (resin material) of the motor housing 20 into the mold 30 and cooling it.

First, the stator 18 and the partition member 22 are set inside the mold (partition member setting step). Next, as an example, a resin material heated to about 340 ° C. is injected into the mold 30 (injection step). Then, the resin material injected into the mold 30 is cooled (cooling step). As a result, as shown in FIG. 3, the motor housing 20 to which the stator 18 and the partition member 22 are fixed is formed.

(Action and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

As shown in FIG. 1, in the electric water pump 10 of the present embodiment, the rotor 16 integrated with the impeller 14 rotates by energizing the winding 18B (coil 18C) of the stator 18. As a result, the pressure of the cooling water flowing from the inlet pipe 12A of the pump case 12 into the inside of the spiral portion 12C (pump chamber 24) is boosted and pumped from the outlet pipe 12B.

Here, in the present embodiment, the partition member 22 is fixed to the motor housing 20 by embedding the first fixing portion 22C, the second fixing portion 22D, and the like of the partition member 22 in the motor housing 20. In this configuration, it is possible to suppress an increase in the number of component parts as compared with a configuration in which the partition member 22 is sandwiched between the motor housing 20 and the pump case 12.

Further, in the present embodiment, after the formation of the motor housing 20 is completed, a force (force in the compression direction) for pressing the first fixed portion 22C from the outer peripheral wall portion 20C to the first fixed portion 22C in the thickness direction thereof is applied. It is supposed to be entered. As a result, it is possible to prevent the liquid in the pump chamber 24 from entering the stator 18 side from between the outer peripheral wall portion 20C and the first fixing portion 22C. Further, since the first fixed portion 22C is continuously connected in the circumferential direction, the force from the outer peripheral wall portion 20C can be received on the entire circumference. Further, no force (force in the shear direction) in the direction orthogonal to the thickness of the first fixed portion 22C is input from the outer peripheral wall portion 20C to the first fixed portion 22C, or almost no force is input in the direction. By preventing the bonding, the bonding state between the outer peripheral wall portion 20C and the first fixing portion 22C can be easily maintained (the joint surface strength can be ensured).

Further, in the present embodiment, after the formation of the motor housing 20 is completed, a force (force in the compression direction) for pressing the second fixed portion 22D from the bottom wall portion 20A to the second fixed portion 22D in the thickness direction thereof is applied. It is designed to be entered. As a result, it is possible to prevent the liquid in the pump chamber 24 from entering the stator 18 side from between the bottom wall portion 20A and the second fixing portion 22D. Further, since the second fixed portion 22D is continuously connected in the circumferential direction, the force from the bottom wall portion 20A can be received all around. Further, no force in the direction orthogonal to the thickness of the second fixed portion 22D (force in the shearing direction) is input from the bottom wall portion 20A to the second fixed portion 22D, or almost no force is input in the direction. The joint state between the bottom wall portion 20A and the second fixing portion 22D can be easily maintained (the joint surface strength can be ensured).

Here, from the viewpoint of further suppressing the intrusion of the liquid into the stator 18, as shown in FIG. 5, between the outer peripheral wall portion 20C and the first fixing portion 22C and between the outer peripheral wall portion 20C and the second fixing portion 20C. It is preferable to provide the adhesive member 32 between the portion 22D and the portion 22D. As the adhesive member 32, a sheet-shaped double-sided tape, an adhesive, a molecular bonding agent used in molecular bonding, or the like can be used. Further, the adhesive member 32 may be provided between the outer peripheral wall portion 20C and one surface of the first fixing portion 22C and the second fixing portion 22D, or may be provided between the outer peripheral wall portion 20C and the first fixing portion. It may be provided between both sides of 22C and the second fixing portion 22D.

Further, from the viewpoint of relaxing the pressing force from the outer peripheral wall portion 20C to the first fixed portion 22C and the second fixed portion 22D, as shown in FIG. 6, between the outer peripheral wall portion 20C and the first fixed portion 22C. A cushioning member 34 may be provided between the outer peripheral wall portion 20C and the second fixing portion 22D. As the cushioning member 34, silicon or the like, which is a member having viscoelasticity, can be used. Further, the cushioning member 34 may be provided between the outer peripheral wall portion 20C and one surface of the first fixing portion 22C and the second fixing portion 22D, or may be provided between the outer peripheral wall portion 20C and the first fixing portion. It may be provided between both sides of 22C and the second fixing portion 22D. Further, the adhesive member 32 shown in FIG. 5 and the cushioning member 34 shown in FIG. 6 are laminated (as an example, a three-layer structure of the adhesive member 32 / cushioning member 34 / adhesive member 32). May be provided between the outer peripheral wall portion 20C and the first fixing portion 22C or between the outer peripheral wall portion 20C and the second fixing portion 22D.

In the example described above, the first fixing portion 22C is bent toward the other side in the axial direction with respect to the first partition portion 22A, and the second fixing portion 22D is radially inside with respect to the second partition portion 22B. Although the example of bending toward is described, the present invention is not limited to this. For example, as shown in FIG. 7, the first fixing portion 22C may be bent toward one side in the axial direction with respect to the first partition portion 22A. Further, as shown in FIG. 8, even if the first fixing portion 22C is bent toward one side in the axial direction with respect to the first partition portion 22A and is inclined toward one side in the axial direction toward the outer side in the radial direction. Good. Further, as shown in FIGS. 9 and 10, a single or a plurality of bent portions 22E may be formed in the intermediate portion in the width direction of the first fixed portion 22C. Further, as shown in FIG. 11, a dish-shaped second fixing portion 22D in which an opening is not formed inside the second fixing portion 22D in the radial direction may be used. Further, as shown in FIG. 12, the first fixing portion 22C may be configured not to be bent with respect to the first partition portion 22A. As described above, the angle and shape of the first fixing portion 22C and the like may be appropriately set in consideration of the shrinkage direction when the resin material around the first fixing portion 22C and the like is cooled.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and can be modified in various ways other than the above within a range not deviating from the gist thereof. Of course.

10 Electric water pump, 12 Pump case, 12A inlet pipe, 12B outlet pipe, 14 impeller, 16 rotor, 18 stator, 20 motor housing (housing), 20A bottom wall, 20B rotary shaft support, 20C outer wall, 22A 1st partition (partition), 22B 2nd partition (partition), 22C 1st fixed part (fixed part, outer annular part), 22D 2nd fixed part (fixed part, inner annular part), 32 Adhesive member , 34 Buffer member

Claims (9)

A stator (18) that generates a rotating magnetic field and
A rotor (16) that is arranged so as to face the stator in the axial direction and that rotates when the stator generates a rotating magnetic field.
An impeller (14) provided so as to be rotatable integrally with the rotor,
It has an inlet pipe (12A) into which the liquid flows in and an outlet pipe (12B) from which the liquid flows out, and the impeller is arranged inside. The rotation of the impeller causes the liquid flowing in from the inlet pipe to flow out from the outlet pipe. Pump case (12) and
A housing (20) in which the stator is supported and the pump case is attached,
A partition member (22C, 22D) having a partition portion (22A, 22B) that separates the space inside the pump case from a portion of the housing to which the stator is fixed, and a fixing portion (22C, 22D) embedded inside the housing. 22) and
Electric water pump (10) equipped with. The electric water pump according to claim 1, wherein the fixed portion is bent toward one side or the other side in the axial direction with respect to the partition portion. The electric water pump according to claim 1 or 2, wherein the fixed portions are continuously connected in the circumferential direction when viewed from the axial direction. Between at least one surface of one side surface and the other side surface of the fixing portion and the housing, at least one surface of the one side surface and the other side surface of the fixing portion and the housing. The electric water pump according to any one of claims 1 to 3, wherein an adhesive member (32) is provided. Between at least one surface of one side surface and the other side surface of the fixing portion and the housing, at least one surface of the one side surface and the other side surface of the fixing portion and the housing. The electric water pump according to any one of claims 1 to 3, which is provided with a cushioning member (34) that is deformed between the two. The electric water according to any one of claims 1 to 5, wherein a force for pressing the fixed portion is input from the housing side to the fixed portion in a state where the fixed portion is embedded in the housing. pump. The housing is formed in a bottomed cylindrical shape with one side open in the axial direction, and protrudes from the bottom wall portion (20A) and the radial center portion of the bottom wall portion toward one side in the axial direction to rotate the rotor. It has a rotating shaft support portion (20B) on which the shaft is supported, and an annular outer peripheral wall portion (20C) that projects from the outside in the radial direction to one side in the axial direction in the bottom wall portion.
The stator is arranged between the rotating shaft support portion and the outer peripheral wall portion of the housing.
The fixing portion is configured to include an outer annular portion (22C) arranged in the outer peripheral wall portion and extending in the circumferential direction.
The electric water pump according to any one of claims 1 to 6, wherein the thickness direction of the outer annular portion is perpendicular to the axial direction. The fixing portion is configured to include an inner annular portion (22D) arranged on the rotation shaft support portion side in the bottom wall portion and extending in the circumferential direction.
The electric water pump according to claim 7, wherein the inner annular portion is inclined to the other side in the axial direction as it goes inward in the radial direction. A mold (30) in which the material forming the housing is injected inside, and
The partition member having the fixing portion whose surface is directed in the direction in which the material contracts when the material injected into the mold is cooled.
Using
The partition member setting process for setting the partition member inside the mold, and
The injection process of injecting the material into the mold and
A cooling step in which the housing in which the fixing portion is embedded is formed by cooling the material injected into the mold.
The method for manufacturing an electric water pump according to any one of claims 1 to 8.