JP7446427B2 - Motor and manufacturing method - Google Patents

Description

The present disclosure relates to a motor and a manufacturing method.

Conventionally, an inner rotor type motor has been developed (for example, see Patent Document 1).

Japanese Patent Application Publication No. 2004-72830

Hereinafter, the annular or substantially annular shape will be collectively referred to simply as "annular shape." The stator core of an inner rotor type motor has an annular portion (hereinafter referred to as "back yoke section") that functions as a back yoke, and a plurality of sections (hereinafter referred to as "back yoke section") that function as multiple teeth. (hereinafter referred to as "teeth portion"). In the motor described in Patent Document 1 (hereinafter referred to as a "conventional motor"), a back yoke portion and individual teeth portions are separately molded (for example, see the summary of Patent Document 1).

Inner rotor type motors are used for various purposes. For example, an inner rotor type motor is used to control the opening of a throttle valve in an automobile, the opening of a wastegate valve in an automobile, or the opening of an EGR (Exhaust Gas Recirculation) valve in an automobile. In such a case, the inner rotor type motor will be used in an environment with high temperatures (hereinafter referred to as "high temperature environment") and in an environment where vibrations occur (hereinafter referred to as "vibration environment"). ) will be used. Therefore, high cooling performance and high vibration resistance are required.

Here, in the conventional motor, the back yoke portion and the individual teeth portions are separately molded as described above. Therefore, an interface exists between the back yoke portion and each tooth portion inside the stator core. The existence of such an interface causes a problem in that the cooling performance deteriorates and the vibration resistance decreases.

The present disclosure has been made to solve the above problems, and aims to improve cooling performance and vibration resistance in an inner rotor type motor.

A motor according to the present disclosure includes a stator core having an annular back yoke portion and a plurality of teeth portions protruding from an inner peripheral portion of the back yoke portion, and a first housing made of an aluminum alloy that holds the stator core. It is an inner rotor type motor in which each tooth part is molded integrally with a back yoke part, the back yoke part is insert-molded in a first housing, and a liquid cooling main body is installed in the first housing. One passage is formed, and a plurality of protrusions are formed on the outer periphery of the back yoke part by insert molding between the back yoke part and the first casing .

According to the present disclosure, with the above configuration, it is possible to improve cooling performance and vibration resistance.

1 is a sectional view showing main parts of a motor according to Embodiment 1. FIG. FIG. 3 is a plan view showing a stator core in the motor according to the first embodiment. FIG. 3 is an explanatory diagram showing a state in which the stator core of the motor according to Embodiment 1 is insert-molded in a first housing. FIG. 2 is a plan view showing a state in which an insulator is provided on the stator core of the motor according to the first embodiment. FIG. 5 is a cross-sectional view taken along line A-A' shown in FIG. 4, showing the first housing, the stator core, and the insulator. FIG. 5 is a cross-sectional view taken along line A-A' shown in FIG. 4 and showing an insulator. FIG. 3 is an explanatory diagram showing a state in which a stator core of a comparative motor is held by a housing. FIG. 3 is an explanatory diagram showing a state in which the stator core of the motor according to the first embodiment is held by a first housing.

Hereinafter, in order to explain this disclosure in more detail, modes for implementing this disclosure will be described with reference to the accompanying drawings.

Embodiment 1.
FIG. 1 is a sectional view showing essential parts of a motor according to a first embodiment. FIG. 2 is a plan view showing a stator core in the motor according to the first embodiment. FIG. 3 is an explanatory diagram showing a state in which the stator core of the motor according to the first embodiment is insert-molded in the first housing. FIG. 4 is a plan view showing a state in which an insulator is provided on the stator core of the motor according to the first embodiment. FIG. 5 is a cross-sectional view taken along line AA′ shown in FIG. 4, and is a cross-sectional view showing the first housing, the stator core, and the insulator. FIG. 6 is a cross-sectional view taken along line AA' shown in FIG. 4, and is a cross-sectional view showing the insulator. The motor according to the first embodiment will be described with reference to FIGS. 1 to 6.

Hereinafter, the direction along the axis A of the motor 100 (D1 in the figure) will be referred to as the "axial direction." Further, the direction of rotation with respect to the axis A (D2 in the figure) is referred to as the "mechanical angle direction".

Motor 100 has stator core 1 . The stator core 1 is made of, for example, laminated steel plates. The stator core 1 has an annular back yoke portion 2 and a plurality of teeth portions 3. In the example shown in FIGS. 1 to 6, the stator core 1 has twelve teeth portions 3. In the example shown in FIGS. The plurality of teeth portions 3 are arranged in the mechanical angle direction D2 and are equally spaced. The individual teeth portions 3 protrude to the inner peripheral portion of the back yoke portion 2.

Here, each tooth portion 3 is integrally formed with the back yoke portion 2. In other words, each tooth portion 3 is formed so as not to be separated from the back yoke portion 2. Further, the stator core 1 is formed so as not to be divided in the mechanical angle direction D2.

The stator core 1 is insert molded into a housing (hereinafter referred to as "first housing") 4 made of aluminum alloy. More specifically, a portion including the outer peripheral portion of the back yoke portion 2 is insert-molded in the first housing 4. That is, the first housing 4 holds the stator core 1. The first housing 4 is manufactured by casting (for example, die casting). That is, the first housing 4 is a cast product (for example, a die-cast product).

Here, a plurality of convex portions 5 are provided on the outer peripheral portion of the back yoke portion 2. In the example shown in FIGS. 1 to 6, twelve convex portions 5 are provided. The plurality of convex portions 5 are arranged in the mechanical angle direction D2 and are equally spaced. Thereby, the shape of the outer peripheral portion of the back yoke portion 2 is gear-shaped. By providing the plurality of convex portions 5, the contact area between the stator core 1 and the first housing 4 can be increased. Moreover, the so-called "anchor effect" can improve the adhesion between the stator core 1 and the first housing 4.

Further, the back yoke portion 2 is provided with a plurality of through hole-shaped holes 6. In the example shown in FIGS. 1 to 6, twelve holes 6 are provided. The plurality of holes 6 are arranged in the mechanical angle direction D2 and are equally spaced apart.

Here, the stator core 1 is provided with an insulator 7 made of resin. The resin enters each hole 6. Thereby, positioning of the insulator 7 with respect to the stator core 1 can be facilitated. Furthermore, the ability of the stator core 1 to hold the insulator 7 can be improved.

Furthermore, a plurality of notch-shaped grooves 8 are provided in the inner peripheral portion of the first housing 4 . In the example shown in FIGS. 1 to 6, twelve grooves 8 are provided. The plurality of grooves 8 are arranged in the mechanical angle direction D2 and are equally spaced.

As described above, when the stator core 1 is provided with the resin insulator 7, the resin enters each groove 8. Thereby, positioning of the insulator 7 with respect to the first housing 4 can be facilitated. Furthermore, the ability of the first housing 4 to hold the insulator 7 can be improved.

A winding 9 is provided around each tooth portion 3. However, the resin of the insulator 7 is interposed between each tooth portion 3 and the winding 9. That is, when the motor 100 is manufactured, the insulator 7 is provided on the stator core 1, and then the winding 9 is provided on the stator core 1.

The stator core 1, the insulator 7, and the winding 9 constitute a main part of the stator 10. The motor 100 has an inverter circuit 11 for supplying current to the stator 10. The inverter circuit 11 is held by a casing 12 made of aluminum alloy (hereinafter referred to as "second casing"). The second housing 12 is manufactured by casting (for example, die casting). That is, the second housing 12 is a cast product (for example, a die-cast product).

The second housing 12 is fixed to the first housing 4 with a plurality of screws (hereinafter referred to as "first screws") 13. A sealing material (hereinafter referred to as "first sealing material") 14 is provided between the first casing 4 and the second casing 12. The first sealing material 14 uses, for example, a packing, a gasket, or an O-ring. The first sealing material 14 may be solid or liquid.

Note that the second housing 12 may be fixed to the first housing 4 by welding. Alternatively, the second housing 12 may be fixed to the first housing 4 by press fitting. In these cases, the plurality of first screws 13 are not necessary.

A rotor 15 is passed through the stator 10. That is, the motor 100 is an inner rotor type. The rotor 15 is rotatably supported by a main bearing 16 and an auxiliary bearing 17. Here, the auxiliary bearing 17 is held by the first housing 4. On the other hand, the main bearing 16 is held by a housing (hereinafter referred to as "third housing") 18 made of sheet metal. The third housing 18 is manufactured by sheet metal pressing.

The third housing 18 is fixed to the first housing 4 with a plurality of screws (hereinafter referred to as "second screws") 19. A sealing material (hereinafter referred to as "second sealing material") 20 is provided between the first casing 4 and the third casing 18. The second sealing material 20 uses, for example, a packing, a gasket, or an O-ring. The second sealing material 20 may be solid or liquid.

Note that the third housing 18 is not limited to being made of sheet metal. For example, the third housing 18 may be made of an aluminum alloy similar to the first housing 4 or the second housing 12. That is, the third housing 18 may be a cast product (for example, a die-cast product).

However, as the material for the third housing 18, it is preferable to use the same material as the material for the main bearing 16 (for example, iron). Thereby, the difference between the coefficient of linear expansion in the third housing 18 and the coefficient of linear expansion in the main bearing 16 can be reduced. As a result, the holding of the main bearing 16 by the third housing 18 can be stabilized against fluctuations in temperature in the environment in which the motor 100 is used.

Furthermore, the third housing 18 may be fixed to the first housing 4 by welding. Alternatively, the third housing 18 may be fixed to the first housing 4 by press fitting. In these cases, the plurality of second screws 19 are unnecessary.

Here, a liquid cooling passage (hereinafter referred to as "first passage") 21 is formed in the first casing 4. In the example shown in FIGS. 1 to 6, the first passage 21 includes a U-shaped (that is, U-shaped) portion disposed around the stator 10. In the example shown in FIGS. The stator 10 is cooled by the cooling liquid (hereinafter referred to as "cooling liquid") flowing in the first passage 21. F in FIG. 3 indicates the flow of the coolant in the first passage 21.

Further, a liquid cooling passage (hereinafter referred to as "second passage") 22 is formed in the second housing 12. The second passage 22 communicates with the first passage 21. In the example shown in FIGS. 1 to 6, the second passage 22 includes a U-shaped (that is, U-shaped) portion disposed around the inverter circuit 11. In the example shown in FIGS. The inverter circuit 11 is cooled by the coolant flowing through the second passage 22 .

In this way, the main parts of the motor 100 are configured.

Next, the application of the motor 100 will be explained. Furthermore, effects due to the structure of the motor 100 will be explained.

Motor 100 is used for various purposes. Specifically, for example, the motor 100 is used in a vehicle-mounted actuator (not shown). The actuator is used to control the opening of an engine valve (not shown). Specifically, for example, the actuator is used to control the opening degree of a throttle valve, a waste gate valve, or an EGR valve.

That is, the motor 100 is used in a high temperature environment and in a vibration environment. Therefore, the motor 100 is required to have high cooling performance and high vibration resistance.

On the other hand, in the motor 100, cooling by liquid cooling is realized as described above. Furthermore, the cooling performance can be improved due to the following factors.

That is, in the motor 100, the back yoke portion 2 and the individual teeth portions 3 are formed in a non-divided manner. Therefore, no interface exists between the back yoke portion 2 and each tooth portion 3 inside the stator core 1. Thereby, heat can be transferred more smoothly from the winding 9 to the first casing 4 via the stator core 1 than in the case where such an interface exists. As a result, the cooling performance of the stator 10 can be improved compared to a motor in which such an interface exists (that is, a conventional motor).

Further, in the motor 100, the back yoke portion 2 is insert-molded in the first housing 4. Further, by forming a plurality of convex portions 5 on the outer circumferential portion of the back yoke portion 2, the contact area between the stator core 1 and the first housing 4 is expanded. Thereby, the transfer of heat from the winding 9 to the first casing 4 via the stator core 1 can be made even smoother. As a result, the cooling performance of the stator 10 can be further improved.

Further, in the motor 100, the vibration resistance can be improved due to the following factors.

That is, as described above, in the motor 100, there is no interface between the back yoke portion 2 and each tooth portion 3. Thereby, the mechanical stability of the stator core 1 can be improved compared to the case where such an interface exists. As a result, vibration resistance can be improved compared to a motor in which such an interface exists (that is, a conventional motor).

Furthermore, as described above, in the motor 100, the back yoke portion 2 is insert-molded in the first housing 4. Further, by forming a plurality of convex portions 5 on the outer circumferential portion of the back yoke portion 2, the contact area between the stator core 1 and the first housing 4 is expanded. Thereby, the ability of the first housing 4 to hold the stator core 1 can be improved. As a result, vibration resistance can be further improved.

Next, other effects due to the structure of the motor 100 will be explained.

In the motor 100, the casing for the inverter circuit 11 (ie, the second casing 12) is constructed from a separate member from the casing for the stator 10 (ie, the first casing 4). Further, the housing for the rotor 15 (that is, the third housing 18) is constituted by a separate member from the housing for the stator 10 (that is, the first housing 4). Thereby, when manufacturing the motor 100, the work of providing the windings 9 can be made easier than when these casings are integrally molded. That is, when installing the winding 9 in a state where the stator core 1 is insert-molded in the first casing 4 and the insulator 7 is provided in the stator core 1, this work is performed on the second casing 12 and the third casing 1. It is possible to avoid interference due to the presence of the casing 18.

Further, each of the two housings (4, 12) is provided with a liquid cooling passage (21, 22), and these passages (21, 22) communicate with each other. In other words, the liquid cooling passage (21, 22) is provided across the two parts (4, 12). Thereby, it is possible to easily manufacture individual casings (4, 12) by casting for the overall shape of the liquid cooling passages (21, 22). Specifically, for example, the shape of the mold used to manufacture the individual housings (4, 12) can be simplified.

Next, a motor 100' for comparison with motor 100 will be described. Also, the differences between the motor 100 and the motor 100' will be explained.

As shown in FIG. 7, the holding of the stator core 1' by the housing 4' in the motor 100' is due to the following action.

That is, the stator core 1' is not insert molded into the housing 4'. The stator core 1' is press-fitted into the housing 4'. Alternatively, the stator core 1' is glued to the housing 4'. Further, the stator core 1' does not have a plurality of protrusions corresponding to the plurality of protrusions 5. In the figure, A' indicates the axis of the motor 100'.

First, the outer circumference of the stator core 1' is in contact with the inner circumference of the housing 4'. Here, since the stator core 1' is press-fitted into the housing 4', friction occurs between the outer circumference of the stator core 1' and the inner circumference of the housing 4'. Alternatively, the outer circumference of the stator core 1' is bonded to the inner circumference of the housing 4'. Therefore, a force for holding the stator core 1' in the axial direction D1' is generated at the contact portion S'_1. Further, in the contact portion S'_1, a force is generated to hold the stator core 1' in the mechanical angle direction D2'.

Second, a stepped portion is formed on the inner peripheral portion of the housing 4'. The stator core 1' is arranged so as to be placed on the stepped surface of the stepped portion (see FIG. 7). That is, the stator core 1 is in contact with the stepped surface. Therefore, a force for holding the stator core 1' in the axial direction D1' is generated at the contact portion S'_2.

On the other hand, in the motor 100, the stator core 1 is insert-molded in the first housing 4 as described above. Further, a plurality of convex portions 5 are provided on the outer peripheral portion of the stator core 1. Therefore, a force that holds the stator core 1 in the mechanical angle direction D2 is generated mainly at the contact portion S_1 (see FIG. 8). Furthermore, a force for holding the stator core 1 in the axial direction D1 is generated at the contact portions S_2 and S_3 (see FIG. 8).

That is, a force for holding the stator core 1 is generated due to the anchor effect. At this time, as described above, the contact area is expanded due to the provision of the plurality of convex portions 5. This improves retention.

Next, a specific example of a method for manufacturing the motor 100 will be described. More specifically, a specific example of a method for manufacturing the first housing 4 and the stator 10 will be described.

<First specific example of manufacturing method>
First, the stator core 1 is manufactured by punching out electromagnetic steel sheets and laminating the punched electromagnetic steel sheets.

Next, the stator core 1 manufactured as described above is insert molded into the first housing 4.

Next, the insulator 7 is insert molded into the stator core 1. At this time, the resin of the insulator 7 enters the individual holes 6, and the resin of the insulator 7 enters the individual grooves 8.

Next, the stator core 1 is provided with a winding 9.

<Second specific example of manufacturing method>
First, the stator core 1 is manufactured by punching out electromagnetic steel sheets and laminating the punched electromagnetic steel sheets.

Further, the insulator 7 is manufactured by resin molding. The shape of the manufactured insulator 7 includes a portion that fits into each hole 6 and a portion that fits into each groove 8.

Next, the stator core 1 manufactured as described above is insert molded into the first housing 4.

Next, the insulator 7 manufactured above is attached to the stator core 1.

Next, the stator core 1 is provided with a winding 9.

The first housing 4 and the stator 10 can be manufactured by this manufacturing method. At this time, as described above, the casing portion of the motor 100 is divided into three parts (4, 12, 18), and the work of installing the winding 9 can be facilitated. That is, when the winding 9 is provided, it is possible to avoid interference with this work due to the fact that the second casing 12 and the third casing 18 are not provided.

Further, by providing the first sealing material 14 and the second sealing material 20, even though the casing of the motor 100 is divided into three parts (4, 12, 18), the motor It is possible to improve the sealing performance in the casing section of 100. As a result, it is possible to prevent foreign matter from entering the inside of the casing of the motor 100.

Next, a modification of the motor 100 will be described.

In the examples shown in FIGS. 1 to 6, each corner of the first housing 4 and the second housing 12 has a right-angled shape. However, the shape of each corner is not limited to a right-angled shape. The shape of each corner may be any shape that can be realized by casting. For example, the shape of each corner may be rounded.

The application of the motor 100 is not limited to an on-vehicle actuator. Further, the use of the actuator is not limited to controlling the opening degree of engine valves. The motor 100 may be used for any purpose as long as it is used in a high temperature environment and a vibration environment.

As described above, the motor 100 according to the first embodiment includes a stator core 1 having an annular back yoke portion 2 and a plurality of teeth portions 3 protruding from the inner peripheral portion of the back yoke portion 2, and a stator core 1 that holds the stator core 1. An inner rotor type motor 100 includes a first housing 4 made of an aluminum alloy, in which each tooth portion 3 is integrally formed with a back yoke portion 2, and the back yoke portion 2 is integrally formed with the first housing 4. The first passage 21 for liquid cooling is formed in the first housing 4 by insert molding. With this structure, it is possible to improve cooling performance and vibration resistance. As a result, the output of the motor 100 can be improved, and the durability of the motor 100 can also be improved.

Further, the stator core 1 is provided with an insulator 7 made of resin, a plurality of grooves 8 are formed in the first casing 4, and the resin of the insulator 7 enters each groove 8. Thereby, positioning of the insulator 7 with respect to the first housing 4 can be facilitated. Furthermore, the ability of the first housing 4 to hold the insulator 7 can be improved.

Further, the stator core 1 is provided with an insulator 7 made of resin, a plurality of holes 6 are formed in the back yoke portion 2, and the resin of the insulator 7 enters each hole 6. Thereby, positioning of the insulator 7 with respect to the stator core 1 can be facilitated. Furthermore, the ability of the stator core 1 to hold the insulator 7 can be improved.

Further, a plurality of convex portions 5 are formed on the outer peripheral portion of the back yoke portion 2. Thereby, the contact area between the stator core 1 and the first housing 4 can be expanded. As a result, cooling performance can be further improved, and vibration resistance can be further improved.

The motor 100 also includes an inverter circuit 11 and a second casing 12 made of aluminum alloy that holds the inverter circuit 11, and a first sealing material between the first casing 4 and the second casing 12. 14 is provided, the second housing 12 is fixed to the first housing 4, a second passage 22 for liquid cooling is formed in the second housing 12, and the second passage 22 is connected to the second housing 12. 1 passage 21 . Since the housing portion of the motor 100 is divided, the work of providing the windings 9 can be facilitated. Further, by providing the second passage 22 communicating with the first passage 21, not only can the stator 10 be cooled with the improved cooling capacity, but also the inverter circuit 11 can be cooled. can.

The motor 100 also includes a rotor 15 and a main bearing 16, and a third housing 18 that holds the rotor 15 and the main bearing 16, and a second housing 18 between the first housing 4 and the third housing 18. A sealing material 20 is provided, and the third housing 18 is fixed to the first housing 4. Since the housing portion of the motor 100 is divided, the work of providing the windings 9 can be facilitated. In addition, by using the same material (for example, iron) as the material of the main bearing 16 for the third housing 18, the third housing 18 can be used as a main bearing against temperature changes in the environment in which the motor 100 is used. The holding of the bearing 16 can be stabilized.

Further, the manufacturing method according to the first embodiment includes a stator core 1 having an annular back yoke portion 2 and a plurality of teeth portions 3 protruding from the inner peripheral portion of the back yoke portion 2, and an aluminum alloy holding the stator core 1. A method for manufacturing an inner rotor type motor 100 comprising a first housing 4 made of plastic, an insulator 7 made of resin provided on a stator core 1, and a winding 9 provided around a tooth portion 3. , a step of molding the stator core 1 by integrally molding the back yoke portion 2 and the individual teeth portions 3; a step of insert molding the back yoke portion 2 into the first housing 4; and a step of molding the insulator 7 into the stator core 1. and a step of providing the winding wire 9. In this way, the first housing 4 and the stator 10 can be manufactured according to the first specific example.

Further, the manufacturing method according to the first embodiment includes a stator core 1 having an annular back yoke portion 2 and a plurality of teeth portions 3 protruding from the inner peripheral portion of the back yoke portion 2, and an aluminum alloy holding the stator core 1. A method of manufacturing an inner rotor type motor 100 comprising a first casing 4 made of plastic, an insulator 7 made of resin provided on a stator core 1, and a winding 9 provided around a tooth portion 3. , a step of molding the stator core 1 by integrally molding the back yoke portion 2 and each tooth portion 3; a step of molding the insulator 7; and insert molding of the back yoke portion 2 into the first housing 4. The method includes a step of attaching the insulator 7 to the stator core 1, and a step of providing the winding 9. In this way, the first housing 4 and the stator 10 can be manufactured according to the second specific example.

Note that within the scope of the present disclosure, any component of the embodiments may be modified or any component of the embodiments may be omitted.

The manufacturing method according to the present disclosure can be used for manufacturing a motor. The motor according to the present disclosure can be used, for example, to control the opening of a throttle valve, control the opening of a wastegate valve, or control the opening of an EGR valve.

DESCRIPTION OF SYMBOLS 1 Stator core, 2 Back yoke part, 3 Teeth part, 4 First housing, 5 Convex part, 6 Hole part, 7 Insulator, 8 Groove part, 9 Winding wire, 10 Stator, 11 Inverter circuit, 12 Second housing, 13 1st screw, 14 1st sealing material, 15 rotor, 16 main bearing, 17 auxiliary bearing, 18 3rd housing, 19 2nd screw, 20 2nd sealing material, 21 1st passage, 22 2nd passage, 100 motor .

Claims (15)

An inner rotor type motor comprising: a stator core having an annular back yoke portion and a plurality of teeth portions protruding from an inner peripheral portion of the back yoke portion; and a first housing made of an aluminum alloy that holds the stator core. And,
Each of the teeth portions is integrally molded with the back yoke portion,
The back yoke portion is insert molded in the first housing,
A first passage for liquid cooling is formed in the first casing,
A motor characterized in that a plurality of convex portions are formed on an outer peripheral portion of the back yoke portion by insert molding between the back yoke portion and the first casing . The motor according to claim 1, wherein the first housing is a cast product. The motor according to claim 2, wherein the first housing is a die-cast product. The stator core is provided with a resin insulator,
A plurality of grooves are formed in the first housing,
The motor according to claim 1, wherein a resin of the insulator is inserted into each of the grooves. The motor according to claim 1, wherein the stator core is formed so as not to be divided in a mechanical angle direction. The stator core is provided with a resin insulator,
A plurality of holes are formed in the back yoke portion,
The motor according to claim 1, wherein a resin of the insulator is inserted into each of the holes. comprising an inverter circuit and a second casing made of aluminum alloy that holds the inverter circuit,
A first sealing material is provided between the first casing and the second casing,
the second housing is fixed to the first housing,
A second passage for liquid cooling is formed in the second casing,
The motor according to claim 1, wherein the second passage communicates with the first passage. 8. The motor according to claim 7, wherein the second casing is fixed to the first casing by a plurality of first screws. comprising a rotor and a main bearing, and a third casing that holds the rotor and the main bearing,
A second sealing material is provided between the first casing and the third casing,
The motor according to claim 1, wherein the third housing is fixed to the first housing. The motor according to claim 9, wherein the third housing is made of sheet metal. 10. The motor according to claim 9, wherein the third casing is fixed to the first casing by a plurality of second screws. 2. The motor according to claim 1, wherein the motor is used for a vehicle-mounted actuator. 13. The motor according to claim 12, wherein the actuator is used to control the opening of an engine valve. a stator core having an annular back yoke portion and a plurality of teeth portions protruding from an inner peripheral portion of the back yoke portion; a first casing made of an aluminum alloy that holds the stator core; and a resin provided in the stator core. A method for manufacturing an inner rotor type motor, comprising: an insulator manufactured by A.
molding the stator core by integrally molding the back yoke portion and each of the teeth portions;
forming a plurality of convex portions on the outer periphery of the back yoke by insert molding the outer periphery of the back yoke into the first housing;
insert molding the insulator into the stator core;
providing the winding;
A manufacturing method characterized by comprising: a stator core having an annular back yoke portion and a plurality of teeth portions protruding from an inner peripheral portion of the back yoke portion; a first casing made of an aluminum alloy that holds the stator core; and a resin provided in the stator core. A method for manufacturing an inner rotor type motor, comprising: an insulator made of aluminum, and a winding provided around the teeth portion, the method comprising:
molding the stator core by integrally molding the back yoke portion and each of the teeth portions;
a step of molding the insulator;
forming a plurality of convex portions on the outer periphery of the back yoke by insert molding the outer periphery of the back yoke into the first housing;
attaching the insulator to the stator core;
providing the winding;
A manufacturing method characterized by comprising:

Images