JP7333887B1 - Stator, electric motor, stator manufacturing method, and electric motor manufacturing method - Google Patents

Abstract

The stator (2) is formed by a stator core (20) and a winding wound around the stator core (20), and protrudes in the axial direction from each of both end faces of the stator core (20) in the axial direction. A coil (21) having a coil end (21a) and a thermally conductive resin part (22) covering the coil end (21a). The thermally conductive resin portion (22) includes a first thermally conductive resin portion (22a) and a second thermally conductive resin portion (22b). The first thermally conductive resin portion (22a) has a first shaft end surface (22c). At least a portion of the first shaft end surface (22c) is provided with a first positioning portion (22d) for contacting the housing (3). The second thermally conductive resin portion (22b) has a second shaft end surface (22f). At least a portion of the second shaft end surface (22f) is provided with a second shaft for contacting a fixture that supports the stator (2) when the stator (2) is placed inside the housing (3). A positioning part (22g) is provided.

Description

The present disclosure relates to a stator including a stator core and coils, an electric motor, a method for manufacturing the stator, and a method for manufacturing the electric motor.

2. Description of the Related Art Conventionally, a stator including a cylindrical stator core and coils is known. A coil is formed by winding a winding around a stator core. The coil has coil ends. The coil end is a portion of the coil that protrudes axially from the axial end face of the stator core. The coil ends are covered with a resin portion.

The stator is arranged inside a cylindrical housing. The housing has an insertion hole for arranging the stator. When arranging the stator inside the housing during the manufacture of the electric motor, it is necessary to position the housing relative to the stator in the axial direction.

In Patent Document 1, an exposed surface exposed from a resin portion is provided on the outer peripheral edge of the end surface in the axial direction of the stator core, and the exposed surface and the stepped surface provided on the inner peripheral surface of the insertion hole of the housing are brought into contact. describes a technique for axially positioning the housing relative to the stator.

WO2022/045166

However, in the technique disclosed in Patent Document 1, since the coil ends cannot be arranged on the exposed surfaces of the axial end face of the stator core, there is a problem that the outer diameter of the coil ends becomes small. .

The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain a stator capable of axially positioning a housing with respect to the stator while increasing the degree of freedom of the outer diameter dimension of the coil end. .

In order to solve the above-described problems and achieve the object, a stator according to the present disclosure is a stator arranged inside a housing of an electric motor, comprising a stator core and windings wound around the stator core. a coil having coil ends protruding in the axial direction from both axial end faces of the stator core; and coils provided on both axial end faces of the stator core to cover the coil ends and a thermally conductive resin portion. The thermally conductive resin portion includes a first thermally conductive resin portion provided on one axial end surface of the stator core and a second thermally conductive resin portion provided on the other axial end surface of the stator core. and a flexible resin portion. The first thermally conductive resin portion has a first axial end surface facing away from the stator core in the axial direction. At least part of the first shaft end face is provided with a first positioning portion for contacting the housing. The second thermally conductive resin portion has a second axial end surface facing away from the stator core in the axial direction. A second positioning portion is provided on at least a portion of the second shaft end surface. A lead wire for connecting the power supply unit and the coil is arranged on the second thermally conductive resin portion. The second positioning portion is a concave portion or a stepped portion that is lower than the height of the portion of the second shaft end surface that is adjacent to the second positioning portion and that can come into contact with the fixture . The second thermally conductive resin portion contains filler. The exposed ratio of the filler exposed on the surface of the second positioning portion is lower than the existence ratio of the filler present in the second thermally conductive resin portion.

The stator according to the present disclosure has the effect of being able to position the housing with respect to the stator in the axial direction while increasing the degree of freedom in the outer diameter dimension of the coil ends.

FIG. 2 is a cross-sectional view showing the electric motor including the stator according to the first embodiment, and is a cross-sectional view along the axial direction; The perspective view which showed the stator concerning Embodiment 1 FIG. 2 is a cross-sectional view showing the stator according to the first embodiment, and is a cross-sectional view along the axial direction; FIG. 4 is a flowchart showing manufacturing steps of the stator according to the first embodiment; FIG. 4 is a cross-sectional view along the axial direction for explaining the installation process and the mounting process of the stator manufacturing method according to the first embodiment; FIG. 4 is a cross-sectional view along the axial direction for explaining the mounting process, the injection process, and the hardening process of the stator manufacturing method according to the first embodiment; FIG. 2 is a flowchart showing manufacturing steps of the electric motor according to the first embodiment; FIG. FIG. 4 is a cross-sectional view along the axial direction for explaining the second step and the third step of the method for manufacturing the electric motor according to the first embodiment; The perspective view showing the stator according to Modification 1 of Embodiment 1. FIG. 4 is a perspective view showing a stator according to Modification 2 of Embodiment 1;

A stator, an electric motor, a method for manufacturing a stator, and a method for manufacturing an electric motor according to embodiments will be described below in detail with reference to the drawings.

Embodiment 1.
FIG. 1 is a cross-sectional view showing an electric motor 1 including a stator 2 according to Embodiment 1, and is a cross-sectional view along the axial direction. The electric motor 1 comprises a stator 2 , a housing 3 , a rotor 4 and two brackets 5 . A stator core 20, which will be described later, of the stator 2 is formed in a cylindrical shape having a central axis C. As shown in FIG. Hereinafter, when describing the direction of each component of the electric motor 1, the direction parallel to the central axis C is defined as the axial direction, the direction perpendicular to the central axis C is defined as the radial direction, and the direction of rotation about the central axis C is defined as the circumferential direction. do.

The housing 3 is formed in a cylindrical shape with both ends in the axial direction open. An insertion hole 30 for arranging the stator 2 is formed in the housing 3 . The housing 3 has a housing-side positioning portion 31 . The housing-side positioning portion 31 is a portion that protrudes radially inward and contacts a first positioning portion 22d of the stator 2, which will be described later. The housing-side positioning portion 31 protrudes radially inward from one axial end of the inner peripheral surface of the insertion hole 30 . The housing-side positioning portion 31 has a contact surface 32 that contacts the first positioning portion 22d. The contact surface 32 is a plane extending in the radial direction and perpendicular to the outer peripheral surface 20 e of the stator core 20 .

The rotor 4 is arranged inside the stator 2 . The rotor 4 is provided with a shaft portion 6 extending along the central axis C of the stator 2 . The brackets 5 are arranged one each at one end and the other end in the axial direction of the housing 3 . Each bracket 5 has a bearing 60 that rotatably supports the shaft portion 6 of the rotor 4 . A shaft portion 6 of the rotor 4 is rotatably supported by two bearings 60 .

The stator 2 is arranged inside the housing 3 of the electric motor 1 . The stator 2 includes a stator core 20 , multiple coils 21 , a thermally conductive resin portion 22 , and multiple lead wires 23 .

FIG. 2 is a perspective view showing the stator 2 according to the first embodiment. FIG. 3 is a cross-sectional view showing the stator 2 according to the first embodiment, and is a cross-sectional view along the axial direction. As shown in FIG. 3, the stator core 20 is formed in a cylindrical shape. The stator core 20 includes, for example, a laminated body in which a plurality of annular thin plates punched from electromagnetic steel plates are laminated in the axial direction. A through-hole 20a extending in the axial direction is formed in the stator core 20 . The rotor 4 shown in FIG. 1 is arranged in the through hole 20a. The stator core 20 has a plurality of teeth 20b. The plurality of teeth 20b are arranged radially around the central axis C. As shown in FIG.

Each of the plurality of coils 21 is formed by winding a winding around the stator core 20 . A coil 21 is formed by winding a wire around each tooth portion 20b. Each coil 21 has coil ends 21a protruding in the axial direction from both end surfaces of the stator core 20 in the axial direction. The coil ends 21a protrude in the direction away from the axial center of the stator core 20 along the axial direction.

Hereinafter, the coil ends 21a protruding axially from one axial end face 20c of the stator core 20 and the coil ends 21a protruding axially from the other axial end face 20d of the stator core 20 are distinguished. In some cases, they are referred to as a first coil end 21b and a second coil end 21c. Although FIG. 3 shows only the coil end 21a of the coil 21, the coil 21 is actually present in the tooth portion 20b of the stator core 20, so the coil 21 extends along the stator core 20. extending axially.

The lead wire 23 electrically connects a power supply portion (not shown) and the terminal portion of the coil 21 . Power is supplied to each coil 21 from a power supply unit via a lead wire 23 . The length of the lead wire 23 is not limited to the illustrated example, and may be changed as appropriate.

As shown in FIG. 2 , the thermally conductive resin portions 22 are provided on both end surfaces of the stator core 20 in the axial direction. The thermally conductive resin portion 22 is formed in a cylindrical shape. As shown in FIG. 3, the thermally conductive resin portion 22 covers the coil ends 21a. The thermally conductive resin portion 22 covers the entire coil end 21a. The thermally conductive resin portion 22 plays a role of transferring heat generated from the coil 21 to the housing 3 .

The thermally conductive resin portion 22 is formed by molding such as potting, for example. The material of the thermally conductive resin portion 22 is resin having thermal conductivity. Examples of such resins include thermosetting resins such as epoxy resins. The thermally conductive resin portion 22 may contain filler or the like. In the present embodiment, outer diameter D1 of stator core 20 and outer diameter D2 of thermally conductive resin portion 22 are the same, but outer diameter D2 of thermally conductive resin portion 22 is equal to outer diameter D1 of stator core 20. is preferably smaller than The reason for this will be described later.

The thermally conductive resin portion 22 has a first thermally conductive resin portion 22a and a second thermally conductive resin portion 22b. The first thermally conductive resin portion 22a is provided on one end surface 20c of the stator core 20 in the axial direction. The first thermally conductive resin portion 22 a covers the first coil ends 21 b of the multiple coils 21 . The second thermally conductive resin portion 22b is provided on the other end surface 20d of the stator core 20 in the axial direction. The second thermally conductive resin portion 22b covers the second coil ends 21c of the plurality of coils 21. As shown in FIG. The first thermally conductive resin portion 22a and the second thermally conductive resin portion 22b may be made of the same resin, or may be made of different resins.

The first thermally conductive resin portion 22a has a first axial end surface 22c facing away from the stator core 20. As shown in FIG. A first positioning portion 22d is provided on the first shaft end face 22c. The first positioning portion 22 d is a portion for contacting the housing 3 when the stator 2 is arranged inside the housing 3 . The first positioning portion 22d is formed by transferring the shape of a mold jig 7, which will be described later, to the first shaft end face 22c during hardening of the resin. Although the first positioning portion 22d is provided on the entire first shaft end surface 22c in the present embodiment, it may be provided on at least a portion of the first shaft end surface 22c. The number of first positioning portions 22d may be plural, but is one in the present embodiment.

The first positioning portion 22d has a first surface 22e extending in the radial direction of the stator core 20. As shown in FIG. Since the first surface 22e is used for axial positioning of the housing 3 when the stator 2 is arranged inside the housing 3, it is preferably perpendicular to the outer peripheral surface 20e of the stator core 20. . The first surface 22e is provided on the entire first positioning portion 22d in this embodiment. That is, in the present embodiment, the first positioning portion 22d is a flat surface extending in the radial direction, and is formed on the entire first shaft end surface 22c. The first surface 22e may be provided on a part of the first positioning portion 22d.

A lead wire 23 for connecting a power supply unit (not shown) and the coil 21 is arranged on the second thermally conductive resin portion 22b. The second thermally conductive resin portion 22b has a second axial end face 22f facing away from the stator core 20. As shown in FIG. A second positioning portion 22g is provided on at least a portion of the second shaft end face 22f. The second positioning portion 22 g is a portion for contacting a fixing jig 10 described later that supports the stator 2 when the stator 2 is arranged inside the housing 3 . The second positioning portion 22g is formed by transferring the shape of a transfer jig 8, which will be described later, to the second shaft end surface 22f during curing of the resin, or formed by additional machining after curing of the resin. . Additional machining means machining such as cutting.

As shown in FIG. 2, the second positioning portion 22g is a recess that is lower in height than the portion of the second shaft end surface 22f adjacent to the second positioning portion 22g. The number of second positioning portions 22g may be one, but in the present embodiment, the number is plural. The plurality of second positioning portions 22g are arranged at equal angles in the circumferential direction. In the present embodiment, the position of the second positioning portion 22g is in the range from the outer peripheral edge of the second shaft end face 22f to the midpoint in the radial direction, but it may be changed as appropriate. The shape of the second positioning portion 22g when viewed along the axial direction is trapezoidal or rectangular. The second positioning portion 22g has a planar concave bottom surface 22h extending in the radial direction and a concave side surface 22i extending axially from the concave bottom surface 22h.

The bottom surface 22h of the recess is located closer to the axial center of the stator core 20 than the rest of the second shaft end surface 22f. The bottom surface 22h of the recess extends radially to form a second surface 22j parallel to the first surface 22e of the first positioning portion 22d. The second surface 22j is preferably perpendicular to the outer peripheral surface 20e of the stator core 20 because it is used for axial positioning of the housing 3 when the stator 2 is arranged inside the housing 3. . The second positioning portion 22g has a second surface 22j extending in the radial direction, and is a portion whose axial position in the stator 2 is determined with reference to the first positioning portion 22d. The axial distance from the first positioning portion 22d to the second positioning portion 22g is strictly controlled. When the second thermally conductive resin portion 22b contains filler, the exposure ratio of the filler exposed on the surface of the second positioning portion 22g is the existence ratio of the filler present in the second thermally conductive resin portion 22b. preferably lower than

At least a portion of the second shaft end surface 22f of the second thermally conductive resin portion 22b forms a curved free surface 22k. Although the planar free surface 22k is illustrated in FIG. 3 and the like, the free surface 22k is actually curved. In the present embodiment, the portion of the second shaft end surface 22f excluding the second positioning portion 22g serves as the free surface 22k. The free surface 22k corresponds to a portion of the liquid surface of the resin that is in contact with the atmosphere before curing when the resin that is the material of the thermally conductive resin portion 22 is cured. In other words, the surface of the liquid surface of the resin before curing that has been cured in contact with the air becomes the free surface 22k. In other words, the free surface 22k is the surface of the liquid surface of the resin before hardening that is hardened while not in contact with other solids such as the transfer jig 8. As shown in FIG. The free surface 22k is a surface with no flatness. In general, it is difficult to utilize the free surface 22k for member positioning.

Next, a method for manufacturing the stator 2 according to this embodiment will be described with reference to FIGS. 4 to 6. FIG. FIG. 4 is a flowchart showing manufacturing steps of the stator 2 according to the first embodiment. FIG. 5 is a cross-sectional view along the axial direction for explaining the installation process and the mounting process of the method for manufacturing the stator 2 according to the first embodiment. FIG. 6 is a cross-sectional view along the axial direction for explaining the mounting process, the injection process, and the hardening process of the method of manufacturing the stator 2 according to the first embodiment. As shown in FIG. 4, the method of manufacturing the stator 2 includes a preparation process, an installation process, a mounting process, an injection process, a curing process, and a removal process.

The preparatory step is a step of winding a winding to form a coil 21 by winding a winding around the stator core 20 shown in FIG. .

The installation step is a step of installing the stator core 20 including the coils 21 in the injection hole 70 of the mold jig 7 in which the injection hole 70 with a bottom is formed. In the installation process, the stator core 20 that has been subjected to the winding process and the wire connection process is installed in the injection hole 70 of the mold jig 7 . In the installation step, the stator core 20 is installed in the injection hole 70 so that the axial direction of the stator core 20 is aligned with the vertical direction. In the installation process, the stator core 20 is installed in the injection hole 70 so that the second coil end 21c to which the lead wire 23 is connected is located above the first coil end 21b.

The mold jig 7 is a container for forming the heat conductive resin portion 22 on the stator core 20 . One axial end of the injection hole 70 is closed. The other axial end of the injection hole 70 is open. The mold jig 7 is installed so that the opening of the injection hole 70 faces upward. A bottom surface portion 71 of the injection hole 70 is a flat surface extending in the radial direction. Stator core 20 is preferably installed in injection hole 70 of mold jig 7 so that outer peripheral surface 20 e of stator core 20 is perpendicular to bottom surface portion 71 of injection hole 70 of mold jig 7 .

The attachment step is a step of attaching the transfer jig 8 to the opening of the injection hole 70 of the mold jig 7 . In FIG. 5, the transfer jig 8 before being attached to the opening of the injection hole 70 of the mold jig 7 is illustrated by a broken line, and the transfer jig 8 after being attached to the opening of the injection hole 70 of the mold jig 7 is shown. The tool 8 is shown in solid lines. The transfer jig 8 is a jig for forming the second positioning portion 22g. The shape of the transfer jig 8 is L-shaped having one side portion 80 and the other side portion 81 . One side portion 80 of the transfer jig 8 extends in the radial direction and is arranged along the opening edge of the injection hole 70 which is the outer peripheral edge of the upper surface of the mold jig 7 . The other side portion 81 of the transfer jig 8 extends in the axial direction and is arranged along the inner peripheral surface of the injection hole 70 inside the injection hole 70 . The transfer jig 8 is arranged above the stator core 20 and the coil ends 21a and away from the stator core 20 and the coil ends 21a.

A lower end surface of the other side portion 81 of the transfer jig 8 serves as a transfer surface 82 forming the second surface 22j of the second positioning portion 22g. The transfer surface 82 is a plane extending in the radial direction. In the mounting process, the transfer surface 82 of the transfer jig 8 is parallel to the bottom portion 71 of the injection hole 70 of the mold jig 7 and the transfer surface 82 of the transfer jig 8 is aligned with the stator core 20 . It is preferable to attach the transfer jig 8 to the opening of the injection hole 70 of the mold jig 7 so as to be perpendicular to the outer peripheral surface 20e. By doing so, the first surface 22e formed by the bottom surface portion 71 of the injection hole 70 of the mold jig 7 and the second surface 22j formed by the transfer surface 82 of the transfer jig 8 become parallel. , the first surface 22 e and the second surface 22 j are perpendicular to the outer peripheral surface 20 e of the stator core 20 . As a result, coaxiality between the housing 3 and the stator 2 can be easily obtained when the stator 2 is arranged inside the housing 3, and workability at the time of assembling the housing 3 and the stator 2 is improved. can be made In the present embodiment, since the transfer jig 8 and the mold jig 7 are directly connected, it is easy to make the transfer surface 82 and the bottom portion 71 parallel to each other. Further, by adjusting the vertical distance from the transfer surface 82 to the bottom surface portion 71, it is possible to adjust the axial distance from the second positioning portion 22g to the first positioning portion 22d shown in FIG. The axial position of the housing 3 with respect to the stator 2 can be accurately determined.

As shown in FIG. 6 , the injection step is a step of injecting the resin 9 into the injection hole 70 of the mold jig 7 . In the injection step, the resin 9 is brought into contact with the bottom portion 71 of the injection hole 70 of the mold jig 7 and at least a portion of the transfer jig 8 is brought into contact with the liquid surface 90 of the resin 9 . Also, in the injection step, the transfer jig 8 is not brought into contact with at least part of the liquid surface 90 of the resin 9 . In the injection step, a portion of the transfer jig 8 including the transfer surface 82 is immersed in the resin 9 . In the injection process, the resin 9 is brought into contact with the entire bottom surface portion 71 of the mold jig 7 .

The curing step is a step of heating and curing the resin 9 . In the curing step, the shape of the bottom portion 71 of the injection hole 70 of the mold jig 7 is transferred to the resin 9 to form the first positioning portion 22d, and the shape of the transfer jig 8 is transferred to the resin. 9 to form the second positioning portion 22g. For example, the resin 9 is heated at 150° C. for 5 hours. By performing the curing step, the thermally conductive resin portions 22 are formed on each of the one end surface 20c and the other axial end surface 20d of the stator core 20, and the coil ends 21a are covered with the thermally conductive resin portions 22. . A portion of the first thermally conductive resin portion 22a to which the shape of the bottom surface portion 71 of the mold jig 7 is transferred serves as a first positioning portion 22d. By making the bottom surface portion 71 flat when manufacturing the mold jig 7, the flat first positioning portion 22d can be easily formed. A portion of the second thermally conductive resin portion 22b to which a part of the shape including the transfer surface 82 of the transfer jig 8 is transferred becomes a second positioning portion 22g. The surface of the liquid surface 90 of the resin 9 that is cured without contacting the transfer jig 8 during the curing step becomes the free surface 22k.

The removal step is a step of removing the mold jig 7 and the transfer jig 8 from the stator 2 including the stator core 20 , the coils 21 and the heat conductive resin portion 22 . By performing the above steps, the stator 2 shown in FIG. 3 is completed.

Next, a method for manufacturing the electric motor 1 will be described with reference to FIGS. 1, 7 and 8. FIG. FIG. 7 is a flowchart showing manufacturing steps of the electric motor 1 according to the first embodiment. FIG. 8 is a cross-sectional view along the axial direction for explaining the second step and the third step of the method for manufacturing the electric motor 1 according to the first embodiment. As shown in FIG. 7, the method for manufacturing electric motor 1 includes a first step, a second step, a third step, and a fourth step.

The first step is to form the stator 2 by the method for manufacturing the stator 2 described above.

As shown in FIG. 8, the second step supports the stator 2 with the fixing jig 10 by bringing the fixing jig 10 into contact with the second positioning portion 22g of the second thermally conductive resin portion 22b. It is a process. In the second step, the stator 2 is installed such that the second thermally conductive resin portion 22b is positioned below the first thermally conductive resin portion 22a. In the second step, the positions of the first thermally conductive resin portion 22a and the second thermally conductive resin portion 22b are upside down compared to when the stator 2 is manufactured as shown in FIG. In the second step, the stator 2 is supported from below by bringing the fixing jig 10 arranged below the stator 2 into contact with the second positioning portion 22g. The fixing jig 10 is installed on a flat surface such as a surface plate (not shown). Therefore, the stator core 20 can be installed so that the outer peripheral surface 20e of the stator core 20 is perpendicular to the surface plate or the like. That is, the stator 2 can be erected on a surface plate or the like.

The shape of the fixing jig 10 is not particularly limited as long as it can support the stator 2 and the outer peripheral surface 20e of the stator core 20 can be perpendicular to the surface plate or the like. As the shape of the fixture 10, for example, as shown in FIG. 8, it is a quadrangular prism which is smaller than the second surface 22j of the second positioning portion 22g and includes a planar support surface 10a. is mentioned. The second surface 22j of the second positioning portion 22g is preferably parallel to the surface plate or the like, but may be inclined with respect to the surface plate or the like. In this case, it is preferable that the support surface 10a of the fixture 10 is also inclined at the same angle as the second surface 22j so that the outer peripheral surface 20e of the stator core 20 is perpendicular to the surface plate or the like. . The first surface 22e of the first positioning portion 22d is also preferably perpendicular to the outer peripheral surface 20e of the stator core 20. As shown in FIG.

The third step is to dispose the stator 2 inside the housing 3 . In FIG. 8 , the housing 3 before the stator 2 is arranged inside the housing 3 is illustrated with a dashed line, and the housing 3 after the stator 2 is arranged inside the housing 3 is illustrated with a solid line. . In the third step, the stator 2 is covered with the housing 3 from above so that the stator 2 is arranged inside the housing 3 . In the third step, the housing side positioning portion 31 protruding radially inward and the first positioning portion 22d of the first thermally conductive resin portion 22a are brought into contact with each other so that the housing 3 is positioned relative to the stator 2. Performs axial positioning. That is, when the stator 2 is arranged inside the housing 3, the contact surface 32 of the housing-side positioning portion 31 and the first surface 22e of the first positioning portion 22d come into contact with each other, and the housing 3 is positioned against the stator 2. Axial position is determined.

Here, fixing between the stator 2 and the housing 3 will be described. When the stator 2 is arranged inside the housing 3, the housing 3 is expanded by preheating the housing 3, or the stator 2 is contracted by precooling the stator 2. FIG. Next, the stator 2 is arranged in the insertion hole 30 of the housing 3 . After that, when the housing 3 is heated, the stator 2 is fitted into the insertion hole 30 of the housing 3 by shrinking the housing 3 when the housing 3 returns to normal temperature. Thereby, the stator 2 and the housing 3 are fixed. On the other hand, when the stator 2 is cooled, the stator 2 is fitted into the insertion hole 30 of the housing 3 by expanding the stator 2 when the stator 2 returns to normal temperature. Thereby, the stator 2 and the housing 3 are fixed.

When the heated housing 3 contracts, a force acts to push the stator 2 inward in the radial direction, and when the cooled stator 2 expands, a force acts to push the housing 3 outward in the radial direction. A stress is generated in the radial direction. At this time, if a large stress is applied to the thermally conductive resin portion 22, the thermally conductive resin portion 22 may break. Therefore, it is preferable that the outer diameter D2 of the heat conductive resin portion 22 is smaller than the outer diameter D1 of the stator core 20 . In this way, when the heated housing 3 contracts or when the cooled stator 2 expands, the stator core 20 and the heat conductive resin portion 22 contact the housing 3 before contact. The housing 3 is in contact. Thereby, the stress generated in the thermally conductive resin portion 22 can be reduced, and breakage of the thermally conductive resin portion 22 can be suppressed. If the stress generated in the thermally conductive resin portion 22 can be contained within a range in which the thermally conductive resin portion 22 does not break, the outer diameter D1 of the stator core 20 and the thermally conductive resin portion 22 may be the same as the outer diameter D2.

In the fourth step, the rotor 4 shown in FIG. 1 is placed on the inner circumference of the stator 2, and brackets 5 are attached to both ends of the housing 3 in the axial direction so as to rotatably support the rotor 4. is a step of arranging the By performing the fourth step, the rotor 4 is rotatably arranged and the rotor 4 and the stator 2 are coaxially arranged. By performing the above steps, the electric motor 1 shown in FIG. 1 is completed.

Next, the effects of the stator 2 and the electric motor 1 according to this embodiment will be described.

In the present embodiment, as shown in FIG. 3, the thermally conductive resin portion 22 includes a first thermally conductive resin portion 22a provided on one end surface 20c of the stator core 20 in the axial direction, and a second thermally conductive resin portion 22b provided on the other axial end surface 20d of the iron core 20. As shown in FIG. Further, in the present embodiment, the first thermally conductive resin portion 22a has a first shaft end face 22c facing away from the stator core 20, and at least part of the first shaft end face 22c is provided with a first positioning portion 22d for contacting the housing 3. As shown in FIG. Further, in the present embodiment, the second thermally conductive resin portion 22b has a second shaft end face 22f facing away from the stator core 20, and at least part of the second shaft end face 22f is provided with a second positioning portion 22g for coming into contact with the fixing jig 10 that supports the stator 2 when the stator 2 is arranged inside the housing 3. As shown in FIG. With these configurations, as shown in FIG. 8, when the stator 2 is arranged inside the housing 3, the second positioning portion 22g of the second thermally conductive resin portion 22b is mounted on a surface plate or the like. By bringing the fixing jig 10 into contact with the fixed jig 10, the stator 2 can be arranged inside the housing 3 in a state in which the stator 2 is erected on a surface plate or the like. Then, by bringing the housing 3 into contact with the first positioning portion 22d of the first thermally conductive resin portion 22a with the stator 2 standing upright on a surface plate or the like, the axial direction of the housing 3 with respect to the stator 2 is adjusted. Positioning can be performed.

As a conventional technique for axially positioning the housing with respect to the stator, for example, a cover is arranged between the outer peripheral surface of the heat conductive resin portion and the inner peripheral surface of the housing, and the cover is positioned opposite to the stator core. There is a technique of providing a flat surface for contacting a housing or a fixture by additional machining on the shaft end face facing the side. However, in this prior art, since a cover is required and additional work for the cover is required, there is a problem that the material cost of the stator and the number of processing steps are increased. In this regard, in the present embodiment, the housing relative to the stator 2 is secured by the first positioning portion 22d of the first thermally conductive resin portion 22a and the second positioning portion 22g of the second thermally conductive resin portion 22b. 3 can be positioned in the axial direction, there is no need to use a positioning cover. In other words, in the present embodiment, the housing 3 can be axially positioned with respect to the stator 2 without using a positioning cover. The number of processing steps can be reduced.

As another prior art for positioning the housing in the axial direction with respect to the stator, as in Patent Document 1, an exposed surface exposed from the resin portion is provided on the outer peripheral edge of the axial end surface of the stator iron core, and this exposed surface is provided. There is a technique for positioning the housing with respect to the stator in the axial direction by bringing the surface into contact with a stepped surface provided on the inner peripheral surface of the insertion hole of the housing. However, in this prior art, since the coil ends cannot be arranged on the portions of the axial end face of the stator core where the exposed surfaces are provided, there is a problem that the outer diameter of the coil ends becomes small. In this respect, in the present embodiment, since the first positioning portion 22d is provided on the first thermally conductive resin portion 22a and the second positioning portion 22g is provided on the second thermally conductive resin portion 22b, the stator It is not necessary to provide an exposed surface for positioning on the axial end face of the iron core 20 . That is, in the present embodiment, since the axial end face of the heat conductive resin portion 22 can position the housing 3 with respect to the stator 2 in the axial direction, the outer diameter of the coil end 21a can be reduced and fixed. It is not necessary to provide an exposed surface for positioning on the axial end face of the daughter core 20 . Thus, in the present embodiment, it is possible to position the housing 3 with respect to the stator 2 in the axial direction while increasing the degree of freedom of the outer diameter dimension of the coil end 21a.

In the present embodiment, as shown in FIG. 3, a portion of the second shaft end surface 22f is a curved free surface 22k. That is, even if the second positioning portion 22g is not formed on the entire second shaft end surface 22f, the stator 2 can be moved by using the second positioning portion 22g provided on a part of the second shaft end surface 22f. The axial positioning of the housing 3 with respect to can be reliably performed.

In the present embodiment, as shown in FIG. 2, the second positioning portion 22g is a recess that is lower than the portion of the second shaft end surface 22f adjacent to the second positioning portion 22g. With this configuration, the housing 3 can be reliably positioned with respect to the stator 2 in the axial direction by bringing the second positioning portion 22g and the housing 3 into contact with each other.

In this embodiment, as shown in FIG. 8, the first positioning portion 22d has a radially extending first surface 22e, and the second positioning portion 22g extends radially to form the first surface. It has a second surface 22j parallel to the surface 22e. With this configuration, coaxiality between the stator 2 and the housing 3 can be easily secured when the stator 2 is arranged inside the housing 3, so workability when assembling the stator 2 and the housing 3 can be improved. can be improved.

In this embodiment, as shown in FIG. 6, when the resin 9 is cured, the shape of the bottom surface portion 71 of the injection hole 70 is transferred to the resin 9 to form the first positioning portion 22d, and a transfer jig is provided. The shape of 8 is transferred to the resin 9 to form the second positioning portion 22g. As a result, the first positioning portion 22d and the second positioning portion 22g can be formed in the thermally conductive resin portion 22 without performing additional processing such as cutting on the thermally conductive resin portion 22. 2, the processing cost and the number of processing steps can be reduced. Further, since the first positioning portion 22d and the second positioning portion 22g can be formed in the thermally conductive resin portion 22 without performing additional machining on the thermally conductive resin portion 22, the thermally conductive resin portion 22 can be When the filler is included, the filler is less likely to be exposed on the surface of the first positioning portion 22d and the surface of the second positioning portion 22g. That is, the exposed ratio of the filler exposed on the surface of the second positioning portion 22g is lower than the existence ratio of the filler present in the second thermally conductive resin portion 22b. Thereby, the appearance of the thermally conductive resin portion 22 can be given a sense of unity. The first positioning portion 22d and the second positioning portion 22g may be formed in the thermally conductive resin portion 22 by performing additional processing such as cutting on the thermally conductive resin portion 22. FIG.

Next, a modification of Embodiment 1 will be described.

The configuration of the second positioning portion 22g is not limited to the illustrated example. For example, the second positioning portion 22g may have the configuration shown in FIG. 9 is a perspective view showing a stator 2 according to Modification 1 of Embodiment 1. FIG. The second positioning portion 22g may be a stepped portion 22m provided at a portion of the outer peripheral edge of the second shaft end face 22f that avoids the lead wire 23, as shown in FIG. In addition to the stepped portion 22m, the second shaft end face 22f is provided with an arrangement portion 22n where the lead wire 23 is arranged and an annular inner peripheral wall 22o. The inner peripheral wall 22o is arranged along the inner peripheral edge of the second shaft end surface 22f. The inner peripheral wall 22o is arranged radially inside the stepped portion 22m and the arrangement portion 22n. The inner peripheral wall 22o and the placement portion 22n have the same height in the axial direction. The stepped portion 22m and the arrangement portion 22n are arranged side by side in the circumferential direction along the outer peripheral edge of the second shaft end surface 22f.

The stepped portion 22m is lower than the height of the portion of the second shaft end surface 22f adjacent to the stepped portion 22m. The stepped portion 22m is lower than the inner peripheral wall 22o and the placement portion 22n. The shape of the stepped portion 22m shown in FIG. 9 when viewed along the axial direction is a C shape. The stepped portion 22m has a planar stepped bottom surface 22p extending radially and circumferentially, and a stepped side surface 22q axially extending from the stepped bottom surface 22p. The stepped bottom surface 22p is located closer to the axial center of the stator core 20 than the arrangement portion 22n and the inner peripheral wall 22o. The stepped bottom surface 22p extends radially to form a second surface 22j parallel to the first surface 22e of the first positioning portion 22d. The stepped side surface 22q connects the inner peripheral edge of the stepped bottom surface 22p and the inner peripheral wall 22o, and also connects the circumferential edge of the stepped bottom surface 22p and the arrangement portion 22n.

For example, the second positioning portion 22g may have the configuration shown in FIG. 10 is a perspective view showing a stator 2 according to Modification 2 of Embodiment 1. FIG. The second positioning portion 22g may be a stepped portion 22m provided along the entire circumference of the outer peripheral edge of the second shaft end face 22f as shown in FIG. The second shaft end face 22f is provided with an annular inner peripheral wall 22o in addition to the stepped portion 22m. The inner peripheral wall 22o is arranged along the inner peripheral edge of the second shaft end surface 22f. The inner peripheral wall 22o is arranged radially inside the stepped portion 22m. The lead wire 23 is arranged on the inner peripheral wall 22o in this modified example. The stepped portion 22m is lower than the height of the portion of the second shaft end surface 22f adjacent to the stepped portion 22m. The stepped portion 22m is lower than the inner peripheral wall 22o. The shape of the stepped portion 22m shown in FIG. 10 when viewed along the axial direction is annular. The stepped portion 22m has a planar stepped bottom surface 22p extending radially and circumferentially, and a stepped side surface 22q axially extending from the stepped bottom surface 22p. The stepped bottom surface 22p is located closer to the axial center of the stator core 20 than the inner peripheral wall 22o. The stepped bottom surface 22p extends radially to form a second surface 22j parallel to the first surface 22e of the first positioning portion 22d. The stepped side surface 22q connects the inner peripheral edge of the stepped bottom surface 22p and the inner peripheral wall 22o.

The position of the second positioning portion 22g is not limited to the illustrated example, and may be changed as appropriate. For example, the second positioning portion 22g may be provided on the inner peripheral edge of the second shaft end surface 22f, or may be provided on a portion other than the outer peripheral edge and the inner peripheral edge of the second shaft end surface 22f. .

In the embodiment described above, the first positioning portion 22d shown in FIG. 3 was a flat surface provided on the entire first shaft end surface 22c. It may be a concave portion or a stepped portion. In such a configuration, the first positioning portion 22d is formed by transferring the shape of the transfer jig 8 to the first shaft end surface 22c during hardening of the resin, or It is formed by additional processing after curing.

In the above-described embodiment, part of the second shaft end face 22f shown in FIG. 3 is the curved free surface 22k, but part of the first shaft end face 22c is the curved free surface 22k. There may be. That is, a part of at least one of the first shaft end face 22c and the second shaft end face 22f may be the curved free surface 22k.

In the above embodiment, the mold jig 7 shown in FIGS. 5 and 6 is a single body, but it may be a split body divided into a plurality of pieces. The size of the stator 2 and the like may be taken into consideration when selecting whether the molding jig 7 should be an integral body or a divided body.

The configuration shown in the above embodiment is an example, and can be combined with another known technique, and part of the configuration can be omitted or changed without departing from the scope. is also possible.

Reference Signs List 1 electric motor 2 stator 3 housing 4 rotor 5 bracket 6 shaft 7 molding jig 8 transfer jig 9 resin 10 fixing jig 10a support surface 20 stator core 20a penetration hole 20b tooth portion 20c one end surface 20d other end surface 20e outer peripheral surface 21 coil 21a coil end 21b first coil end 21c second coil end 22 thermally conductive resin portion 22a first Thermally conductive resin portion 22b Second thermally conductive resin portion 22c First shaft end surface 22d First positioning portion 22e First surface 22f Second shaft end surface 22g Second positioning portion 22h recess bottom surface 22i recess side surface 22j second surface 22k free surface 22m stepped portion 22n arrangement portion 22o inner peripheral wall 22p step bottom surface 22q step side surface 23 lead wire 30 insertion hole 31 housing side positioning Part 32 Contact surface 60 Bearing 70 Injection hole 71 Bottom surface 80 One side 81 Other side 82 Transfer surface 90 Liquid surface C Central axis D1, D2 Outer diameter.

Claims (8)

A stator disposed inside the housing of the electric motor,
a stator core;
a coil formed by winding a winding around the stator core and having coil ends protruding in the axial direction from both end surfaces of the stator core in the axial direction;
a thermally conductive resin portion provided on each of both axial end surfaces of the stator core and covering the coil end,
The thermally conductive resin portion is
a first thermally conductive resin portion provided on one end surface of the stator core in the axial direction;
a second thermally conductive resin portion provided on the other end surface of the stator core in the axial direction;
The first thermally conductive resin portion has a first axial end surface facing away from the stator core in the axial direction,
At least part of the first shaft end face is provided with a first positioning portion for contacting the housing,
the second thermally conductive resin portion has a second axial end surface facing away from the stator core in the axial direction;
A second positioning portion is provided on at least a portion of the second shaft end surface,
A lead wire for connecting a power supply unit and the coil is arranged in the second thermally conductive resin portion,
the second positioning portion is a recessed portion or a stepped portion that is lower than the height of a portion of the second shaft end surface adjacent to the second positioning portion and is capable of coming into contact with a fixture ;
The second thermally conductive resin portion contains a filler,
A stator, wherein the exposed ratio of the filler exposed on the surface of the second positioning portion is lower than the existence ratio of the filler present in the second thermally conductive resin portion. 2. The stator according to claim 1, wherein a portion of at least one of said first shaft end face and said second shaft end face is a curved free surface. The first positioning portion has a first surface extending in the radial direction of the stator core,
3. The stator according to claim 1, wherein said second positioning portion has a second surface extending in said radial direction and parallel to said first surface. A stator according to claim 1 or 2 ;
a housing in which the stator is disposed;
a rotor arranged on the inner circumference of the stator;
brackets having bearings arranged at one end and the other end of the housing in the axial direction to rotatably support the rotor;
The electric motor, wherein the housing has a housing-side positioning portion that protrudes radially inward of the stator core and contacts the first positioning portion. A stator according to claim 3 ;
a housing in which the stator is disposed;
a rotor arranged on the inner circumference of the stator;
brackets having bearings arranged at one end and the other end of the housing in the axial direction to rotatably support the rotor;
The electric motor, wherein the housing has a housing-side positioning portion that protrudes radially inward of the stator core and contacts the first positioning portion. a stator core, a coil formed by winding a winding around the stator core and having coil ends protruding in the axial direction from both end surfaces of the stator core in the axial direction, and the stator core. and a thermally conductive resin portion provided on each of the axial end surfaces and covering the coil ends, wherein the thermally conductive resin portion is provided on one axial end surface of the stator core. A first thermally conductive resin portion and a second thermally conductive resin portion provided on the other end surface of the stator core in the axial direction, wherein the first thermally conductive resin portion comprises: It has a first shaft end face facing away from the stator core in the axial direction, and at least part of the first shaft end face is provided with a first positioning portion for contacting the housing. , the second thermally conductive resin portion has a second shaft end face facing away from the stator core in the axial direction, and at least a part of the second shaft end face is provided with the housing A second positioning portion is provided for contacting a fixing jig that supports the stator when the stator is arranged inside the second heat conductive resin portion, the power supply portion and the coil and the second positioning portion is lower than the height of a portion of the second shaft end face adjacent to the second positioning portion, and is in contact with the fixture. The second thermally conductive resin portion includes a filler, and the exposure ratio of the filler exposed on the surface of the second positioning portion is the second thermally conductive resin portion. A method for manufacturing a stator in which the abundance ratio of the filler present in the portion is lower than that of the portion ,
an installation step of installing the stator core including the coil in the injection hole of a mold jig having a bottomed injection hole;
an injection step of injecting resin into the injection hole of the mold jig;
A curing step of heating and curing the resin;
a removing step of removing the mold jig from the stator including the stator core, the coil, and the thermally conductive resin portion;
The first positioning portion is formed by transferring the shape of the mold to the resin in the curing step, or formed by machining the thermally conductive resin portion after the curing step. ,
A method of manufacturing a stator, wherein the second positioning portion is formed by transferring the shape of the mold to the resin in the curing step. An attachment step of attaching a transfer jig to the opening of the injection hole of the mold jig,
In the injection step, resin is injected into the injection hole of the mold jig, the resin is brought into contact with the bottom surface of the injection hole of the mold jig, and at least part of the transfer jig is filled with the liquid of the resin. contact the surface,
In the curing step, the resin is heated and cured, and the shape of the bottom surface of the injection hole of the mold jig, which is the mold, is transferred to the resin to form the first positioning portion. forming the second positioning portion by transferring the shape of the transfer jig, which is a mold, to the resin;
7. The fixing according to claim 6 , wherein in the removing step, the mold jig and the transfer jig are removed from the stator including the stator core, the coil, and the thermally conductive resin portion. Child production method. a first step of forming the stator by the stator manufacturing method according to claim 6 or 7 ;
a second step of supporting the stator with the fixing jig by bringing the fixing jig into contact with the second positioning portion of the second thermally conductive resin portion;
disposing the stator inside a housing, and bringing the housing-side positioning portion protruding radially inward of the stator core into contact with the first positioning portion of the first thermally conductive resin portion; a third step of axially positioning the housing by
disposing a rotor on the inner periphery of the stator, and disposing brackets on each of the axial ends of the housing so as to rotatably support the rotor. A method of manufacturing an electric motor, characterized by:

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