WO2018180720A1

WO2018180720A1 - Electric motor and method for producing same

Info

Publication number: WO2018180720A1
Application number: PCT/JP2018/010855
Authority: WO
Inventors: 唯増田
Original assignee: Ntn株式会社
Priority date: 2017-03-28
Filing date: 2018-03-19
Publication date: 2018-10-04
Also published as: JP2018166352A

Abstract

Provided are: an axial gap-type electric motor wherein a motor core can be produced with ease and precision, and production costs can be reduced; and a method for producing same. This electric motor is an axial gap-type electric motor provided with a housing, a stator (2) held static to the housing, and a rotor (3) supported so as to be able to rotate relative to the stator (2), the stator (2) and the rotor (3) facing in the direction of the axis of rotation of the rotor (3). The stator (2) is provided with a core (7) including a yoke section (8) extending in a circumferential direction and a plurality of magnetic pole sections (9) that protrude out in the axial direction from this yoke section (8) and are lined up in the circumferential direction. This core (7) has a cylindrical shape in which one end and the other end of the yoke section (8) in the circumferential direction are close together. A plurality of magnetic bodies (13), which have, in an integral manner, sections constituting the yoke section (8) and sections constituting the magnetic pole sections (9) are arranged concentrically.

Description

Electric motor and method for manufacturing the same

Related applications

This application claims the priority of Japanese Patent Application No. 2017-062138 filed on Mar. 28, 2017, which is incorporated herein by reference in its entirety.

The present invention relates to an electric motor used in various devices such as an electric brake device and a method for manufacturing the same.

The following proposals have been made for electric motors.
1. An electric brake device using a motor and a linear motion mechanism (Patent Document 1).
2. Axial gap type motor (Patent Document 2).
3. A method of manufacturing an iron core of an axial gap type motor that winds a ribbon-shaped magnetic plate to be a core (Patent Document 3).

JP-A-6-327190 Japanese Patent Laid-Open No. 3-15255 JP 2010-233324 A

In an electric brake device using an electric linear actuator as described in Patent Document 1, it is generally desired to realize an electric actuator that is as space-saving and highly responsive as possible. As a structure of an electric motor that enables high torque while saving space, for example, an axial gap type electric motor as shown in Patent Document 2 is known. However, compared to a radial gap type electric motor in which the magnetic circuit is formed on a plane, the axial gap type electric motor has a three-dimensional magnetic circuit. May be a problem.

For example, when forming a structure as in Patent Document 2, it is necessary to manufacture the magnetic pole part and the yoke part separately and fix them by welding or the like. In that case, especially in the case of a small motor, accurate positioning of the magnetic pole part and the yoke part may be difficult. Further, in the case of a small motor, the magnetic pole part is particularly small, so that it may be difficult to manufacture the core part, for example, the laminated steel sheet (laminated core) may be peeled off during processing.

For example, in the manufacturing method described in Patent Document 3, processing tolerances that occur during punching or in the process of winding the magnetic plate continue to be accumulated in the winding process. For this reason, it may be difficult to guarantee the dimensions or shape during mass production. In addition, the thicker the magnetic material to be wound, the more difficult it is to wind, and the thinner the magnetic plate to be wound, the longer the length to be wound. There is a case.

An object of the present invention is to provide an electric motor capable of easily and accurately manufacturing a motor iron core in an axial gap type electric motor and reducing the manufacturing cost, and a method for manufacturing the same. .

An electric motor according to the present invention includes a housing, a stator statically held in the housing, and a rotor rotatably supported by the stator, and the stator and the rotor are An axial gap type electric motor facing the direction of the rotation axis of the rotor,
One or both of the stator and the rotor are
A yoke having a yoke portion extending in a circumferential direction of the rotating shaft and a plurality of magnetic pole portions protruding from the yoke portion in the axial direction of the rotating shaft and arranged in the circumferential direction of the rotating shaft;
The iron core has a cylindrical shape in which one end portion and the other end portion in the circumferential direction of the yoke portion are close to each other, and integrally includes a portion constituting the yoke portion and a portion constituting the magnetic pole portion. A plurality of magnetic bodies are arranged concentrically.

According to this configuration, since the iron core integrally includes the portion constituting the yoke portion and the portion constituting the magnetic pole portion, the manufacturing process for fixing the magnetic pole portion and the yoke portion can be reduced, and the magnetic pole portion and the yoke can be reduced. There is no need to position the part accurately. The iron core is arranged concentrically with a plurality of magnetic bodies that integrally have a portion that constitutes the yoke portion and a portion that constitutes the magnetic pole portion. Processing tolerances can be reduced. Therefore, the iron core can be manufactured easily and accurately, and the manufacturing cost can be reduced. Since this electric motor has an iron core in which magnetic bodies are arranged concentrically, an axial gap type electric motor with low loss of eddy current and high output can be configured.

The magnetic body has a facing surface portion where one end portion and the other end portion in the circumferential direction of the yoke portion face each other,
A plurality of the opposing surface portions may be provided at different positions in the circumferential direction.
Thus, the permeability can be improved by forming the facing surface portion into a so-called stepped shape. Further, the shape of the iron core can be easily formed into a cylindrical shape.

The one end and the other end may have a protrusion protruding in the circumferential direction, and the protrusion at the one end and the protrusion at the other end may be close to each other in the axial direction. An air gap may be generated in the circumferential facing surface due to the influence of dimensional tolerance. On the other hand, it is easy to eliminate the gap or reduce the gap in the axially facing surface portion. Therefore, since the protruding portion at one end and the protruding portion at the other end are brought close to each other in the axial direction, the magnetic flux passes through the opposing surface portion in the axial direction, thereby mitigating the decrease in permeability due to the circumferential air gap. be able to.

The magnetic body has a facing surface portion in which one end portion and the other end portion in the circumferential direction of the yoke portion face each other.
The opposing surface portion of the first magnetic body of the plurality of magnetic bodies and the opposing surface portion of the second magnetic body of the plurality of magnetic bodies may be formed at different positions in the circumferential direction.
In this case, the permeability can be improved as compared with an iron core or the like in which the opposing surface portions are arranged in the same phase.

An annular holding member that holds the outer periphery of the iron core including the plurality of magnetic bodies may be provided. In this case, the shape of the iron core formed into a cylindrical shape can be reliably held by the holding member. This holding member may also be used as a housing. In this case, the number of parts of the electric motor can be reduced and the structure can be simplified.

The magnetic body may be provided with a welded portion in which portions close to one end and the other end of the yoke portion are welded. In this case, the shape of the iron core formed into a cylindrical shape can be permanently retained.

The manufacturing method of each electric motor described above includes a lamination process of laminating a plurality of thin plate-like magnetic bodies, and forming the iron core by bending the plurality of magnetic bodies laminated in the lamination process into a cylindrical shape and a concentric shape. Bending process. Due to the lamination process of the plurality of magnetic bodies and the bending process of bending the laminated plurality of magnetic bodies in a cylindrical and concentric manner, the iron core is, for example, one end and the other end in the circumferential direction of the yoke part. A plurality of magnetic bodies having a cylindrical shape adjacent to each other and having a portion constituting the yoke portion and a portion constituting the magnetic pole portion are arranged concentrically.

According to this configuration, a plurality of thin plate-like magnetic bodies are laminated in the lamination process. In the bending process, the iron core is formed by bending a plurality of the magnetic bodies stacked in the stacking process in a cylindrical shape and concentrically. A plurality of magnetic bodies stacked in this way can be bent cylindrically and concentrically to form an iron core, which facilitates processing and reduces processing tolerances compared to conventional examples in which a magnetic plate is wound. Can do. Therefore, the iron core can be manufactured easily and accurately, and the manufacturing cost can be reduced. The electric motor manufactured by using this manufacturing method has an iron core in which a plurality of magnetic bodies are cylindrically and concentrically stacked, so that it constitutes an axial gap type electric motor with high eddy current loss and high output. it can.

Any combination of at least two configurations disclosed in the claims and / or the specification and / or the drawings is included in the present invention. In particular, any combination of two or more of each claim in the claims is included in the invention.

The present invention will be understood more clearly from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and drawings are for illustration and description only and should not be used to define the scope of the present invention. The scope of the invention is defined by the appended claims. In the accompanying drawings, the same reference numerals in a plurality of drawings indicate the same or corresponding parts.

It is sectional drawing of the electric motor which concerns on one Embodiment of this invention. It is a perspective view of the iron core of the same electric motor. It is a perspective view which shows the state which laminated | stacked multiple magnetic bodies of the same iron core. It is a front view of the same iron core. It is a side view of the iron core. It is a perspective view which shows the state which laminated | stacked and positioned each magnetic body of the same iron core. It is a perspective view which shows the state which bent the said each magnetic body cylindrically and concentrically. (A) is the front view which shows the components which comprise the housing of the same electric motor from the inside, (B) is VIIIB-VIIIB sectional drawing of the same figure (A). It is a perspective view which shows the state which inserted the stator containing an iron core and a coil in the components which comprise the housing. It is a perspective view which shows the manufacturing method of the electric motor which concerns on other embodiment of this invention. It is a perspective view of the iron core etc. of the same electric motor. It is a perspective view which shows the manufacturing method of the electric motor which concerns on further another embodiment of this invention. It is a perspective view of the magnetic body of the electric motor which concerns on further another embodiment of this invention. It is a bottom view of the iron core which shape | molded each said magnetic body in the cylindrical shape. It is a perspective view of the magnetic body of the electric motor which concerns on further another embodiment of this invention. It is a front view of the iron core which shape | molded each said magnetic body in the cylindrical shape. It is sectional drawing which shows the linear motion actuator using the electric motor which concerns on any embodiment.

An electric motor according to an embodiment of the present invention will be described with reference to FIGS. The following description includes a description of a method for manufacturing an electric motor.
<Overall structure of electric motor>
As shown in FIG. 1, the electric motor M includes a housing 1, a stator 2, and a rotor 3. The electric motor M is an axial gap type in which the stator 2 and the rotor 3 face each other in the direction of the rotating shaft 5 of the rotor 3. The stator 2 is statically held by the housing 1. The rotor 3 is supported so as to be rotatable with respect to the stator 2. A rotating shaft 5 is rotatably supported on the housing 1 via a bearing 4, and a rotor 3 is fixed to the outer periphery of the rotating shaft 5.

The housing 1 is composed of a plurality of divided

housings

1A and 1B, and a stator 2 is installed in one of the divided housings 1A. The other divided housing 1B also serves as a housing of the motor using device 6 that uses the electric motor M, that is, a part of the housing of the motor using device 6 becomes a motor housing. The motor using device 6 includes, for example, a linear actuator described later.

The axial gap type electric motor M is a permanent magnet type synchronous motor, and the stator 2 is an excitation mechanism for an assembly part having an iron core 7 and a coil 10. The rotor 3 is formed by embedding a plurality of permanent magnets 3a arranged in the circumferential direction in a disc-shaped holding member 3b. The holding member 3b may be a metal member or a resin member. The rotor 3 may be entirely made of a magnetic material instead of the permanent magnet 3a and the holding member 3b. In that case, the rotor 3 becomes a reluctance type synchronous motor by having a shape in which the reluctance varies depending on the phase of the rotor.

<About the structure of the motor core>
As shown in FIG. 2, the iron core 7 in the stator 2 includes a yoke portion 8 that is a back yoke and a plurality of magnetic pole portions (magnetic pole cores) 9. As shown in FIGS. 1 and 2, the yoke portion 8 is a cylindrical or annular flat plate shape that is concentric with the rotation axis O of the rotor 3 and extends in the circumferential direction of the rotation shaft 5. Form a road. The magnetic pole portions 9 protrude from the yoke portion 8 in the axial direction of the rotary shaft 5 and are arranged at equal intervals in the circumferential direction of the rotary shaft 5 to form magnetic poles.

As shown in FIG. 5, the iron core 7 has a cylindrical shape in which one end portion 11 and the other end portion 12 in the circumferential direction are close to each other, and a portion constituting the yoke portion 8 and a portion constituting the magnetic pole portion 9. Are formed by laminating a plurality of substantially cylindrical magnetic bodies 13 concentrically. That is, the iron core 7 is formed by laminating a plurality of thin plate-like (that is, substantially cylindrical) magnetic bodies 13 that form an arc whose starting point and end point are close to one circumferential direction. In other words, the iron core 7 has a plurality of magnetic bodies 13 arranged concentrically.

A portion where a plurality of yoke portions 8 are stacked forms a magnetic circuit parallel to the rotation plane of the rotation shaft 5 (FIG. 1). FIG. 3 is a perspective view showing a state in which a plurality of flat magnetic bodies 13 of the iron core 7 are stacked. The magnetic body 13 in the figure has a shape in which a cylindrical magnetic body 13 (FIG. 4) in which the magnetic pole portion 9 and the yoke portion 8 are integrally provided is developed in a plane in the circumferential direction. For example, when the magnetic body 13 is made of an electromagnetic steel plate or the like whose surface is insulated, a low-cost and high-power motor can be configured. In each magnetic body 13 developed in a plane shown in FIG. 3, when the iron core 7 is formed in the cylindrical shape, the plurality of magnetic pole portions 9 are arranged at equal intervals in the circumferential direction as shown in FIG. It arrange | positions so that it may become a fan shape.

As shown in FIG. 4, the shape of the portion corresponding to the magnetic pole portion 9 of the laminated magnetic bodies 13 gradually changes in the radial direction (lamination direction) of the iron core 7. In other words, the portion where the plurality of magnetic pole portions 9 are stacked has a fan shape in which the arc portion is located on the outer diameter side in a front view. Specifically, as shown in FIG. 3 and FIG. 4, the magnetic pole portions 9 arranged at equal intervals in the circumferential direction are arranged so as to have the same phase for each layer, and the magnetic pole portions 9 of the inner diameter side layer are arranged as much as possible. It is formed narrow. As a result, as shown in FIG. 2, the fan-shaped magnetic pole portion 9 is formed in a front view that becomes wider as it goes toward the outer diameter side layer. In general, the number of the magnetic pole portions 9 is preferably an integer multiple of the number of phases of the alternating current to be applied. However, the number of the magnetic pole portions 9 may be reduced in some phases. For example, since the illustrated example is a three-phase motor, the number of the magnetic pole portions 9 is twelve, which is four times the number of phases “3”. For example, U-phase 4 poles, V-phase 4 poles , W phase 3 poles, a total of 11 can be configured.

<About the coil 10>
As shown in FIG. 1 and FIG. 9, the coil 10 is one in which a conductive wire is wound around each magnetic pole portion 9, and the magnetic pole portion 9 and the coil 10 wound around the magnetic pole portion 9 One individual excitation mechanism for converting the current into the linkage flux is configured. The conductor of the coil 10 shown in FIG. 9 is a covered conductor having a rectangular cross section, and is wound around the outer periphery of the magnetic pole portion 9 in a single line along the protruding direction via a coil bobbin (not shown).

In addition, the winding of the said conducting wire may be single, and may be wound in multiple. The conducting wire may be a coated conducting wire having a circular cross section. The conductive wire may be wound around a coil bobbin (not shown) fitted on the outer periphery of each magnetic pole portion 9 as described above, or directly wound through insulating paper or the like and fixed by varnish or mold. May be.

<Examples of motor core molding>
FIG. 6 is a perspective view showing a state in which the magnetic bodies 13 are laminated and positioned in the lamination process included in the manufacturing method. FIG. 6 shows the process of forming each magnetic body 13 of FIG. 3 into the cylindrical shape of FIGS. 4 and 5. In this example of forming the iron core 7, the first and second forming members 14, 15 (15a), which are jigs for forming the inner peripheral surface and the outer peripheral surface of the iron core 7 into a predetermined shape, are sandwiched between the two, A laminated magnetic body is formed.

As shown in FIG. 6, the first molding member 14 is a member that molds the inner peripheral surface of the iron core 7, and integrally includes a molding member main body 14a and a positioning member 14b. The molded member body 14a has a cylindrical shape or a columnar shape having an outer peripheral surface having the same diameter as the inner peripheral surface of the iron core 7 after molding. The positioning member 14b is a member that guides and positions a part of the slot groove of the iron core 7, and has a prismatic shape that protrudes from the part of the outer peripheral surface of the molded member main body 14a in the circumferential direction to the outer diameter side by a predetermined distance. . The predetermined distance is determined according to the radial thickness between the inner peripheral surface and the outer peripheral surface after the iron core 7 is molded.

The member for positioning the iron core 7 may be provided with a positioning member (not shown) protruding toward the inner diameter side by a predetermined distance toward the inner peripheral surface of the second molding member 15. Positioning members may be provided on both of the second molded

members

14 and 15. When the positioning member is provided on one or both of the first and

second molding members

14 and 15, it is easy to guarantee the shape of the iron core 7 after molding. Instead of using the positioning member, the iron core 7 may be positioned by temporary fixing such that the magnetic pole portions 9 are aligned in phase and a predetermined position of each magnetic body 13 is bonded or welded in advance.

FIG. 7 is a perspective view showing a state in which each magnetic body 13 is bent into a cylindrical shape and concentrically in a bending process included in the above manufacturing method. In this bending process, the iron core 7 is formed by bending the plurality of magnetic bodies 13 stacked in the stacking process into a cylindrical shape and concentric shape. The second molding member 15 is a member that molds the outer peripheral surface of the iron core 7, and includes a plurality of divided forming jigs 15 a having an inner peripheral surface having the same diameter as the outer peripheral surface of the iron core 7 after molding. FIG. 7 shows an example in which the forming jig 15a divided into three parts is used. However, the number of divisions of the forming jig 15a can be set arbitrarily according to the convenience of facilities and the like.

Each of the forming jigs 15a may be a forming jig 15a that is divided into three in the same shape every about 120 ° as shown in FIG. 7. Although not shown, for example, the center angle is 180 degrees. It may be a forming jig divided into three parts having different shapes such as °, 90 °, and 90 °. Moreover, the 2nd shaping | molding member 15 should just be provided with the shape sufficient for shaping | molding of the iron core 7, has a space | gap between shaping | molding jigs, and the sum total of the center angle which combined all the shaping | molding jigs is about 360. It may be a split-type molded member having a shape that does not become ° (less than 360 °).

<Example of assembly of excitation mechanism>
As shown in FIGS. 8A and 8B, the outer peripheral surface of the yoke portion 8 (FIG. 1) is fitted to the bottom surface of the divided housing 1 </ b> A (for example, the outer peripheral surface may be circumscribed, and by the fitting) A polygonal fitting groove 16 may be provided (which may be somewhat deformed). The fitting groove 16 allows easy positioning of the excitation mechanism relative to the divided housing 1A when the excitation mechanism is assembled.

The divided housing 1A may be a resin-molded one such as PBT, or may be a metal member. When the divided housing 1A is made of a resin member, for example, a bus bar for wiring or the like may be insert-molded. When the divided housing 1A is made of a metal material, it may be a magnetic body such as iron or a nonmagnetic material such as aluminum or stainless steel. Alternatively, the divided housing 1A may be formed of a resin member, and a metal case such as aluminum may be separately provided and combined.

<Effect>
According to the electric motor M described above, the iron core 7 integrally includes a portion constituting the yoke portion 8 and a portion constituting the magnetic pole portion 9, and thus a manufacturing process for fixing the magnetic pole portion 9 and the yoke portion 8. In addition, the magnetic pole portion 9 and the yoke portion 8 need not be positioned accurately. Since the iron core 7 is formed by concentrically laminating the magnetic body 13 integrally including the portion constituting the yoke portion 8 and the portion constituting the magnetic pole portion 9, the conventional example of winding the magnetic plate is facilitated. As a result, machining tolerance can be reduced. Therefore, the iron core 7 can be manufactured easily and accurately, and the manufacturing cost can be reduced. Since this electric motor M has the iron core 7 in which the magnetic bodies 13 are concentrically stacked, it is possible to configure an axial gap type electric motor M with high loss and low eddy current loss.

<About other embodiments>
In the following description, in each embodiment, portions corresponding to the matters described in advance are denoted by the same reference numerals, and redundant description is omitted. When only a part of the configuration is described, the other parts of the configuration are the same as those described in advance unless otherwise specified. The same effect is obtained from the same configuration. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined as long as the combination does not hinder.

As shown in FIG. 11, an annular holding member 17 that holds the outermost periphery of the laminated magnetic bodies 13 may be provided. The holding member 17 is a ring member that can be fitted to the outer peripheral surface of the iron core 7 and has a predetermined fitting tolerance with respect to the outer peripheral surface of the iron core 7. As shown in FIG. 10, the iron core 7 is formed by the first and second forming

members

14 and 15. Next, the first molding member 14 and the holding member 17 are concentric, and the inner peripheral surface of the second molding member 15 and the inner peripheral surface of the holding member 17 are adjacent to each other in a seamless state. In addition, the holding member 17 is brought into contact with the end surface of the second molding member 15. Thereafter, the molded iron core 7 is pulled out to the holding member side (right side in FIG. 10) and inserted (fitted) to the inner peripheral surface of the holding member 17. As shown in FIG. 11, the holding member 17 can reliably hold the cylindrical shape of the molded iron core 7. As the holding member 17, as shown in FIG. 11, a holding-dedicated ring member that holds the iron core 7 may be used. Alternatively, the holding member 17 may also be used as a housing that is a component of the electric motor. In this case, the number of parts of the electric motor can be reduced and the structure can be simplified.

As shown in FIG. 12, the magnetic body 13 may be provided with a welded portion 18 where the circumferential portion of the yoke portion 8 is welded at a location close to the other end. The welded portion 18 may be a circumferentially facing surface portion (a surface portion where one end portion and the other end portion face each other) of all the laminated magnetic bodies 13 or mainly a magnetic body on the outer diameter side. It may be a part of the counter surface portion such as the 13 counter surface portions in the circumferential direction. In this case, the shape of the iron core formed into a cylindrical shape can be permanently maintained. In addition, although not illustrated, for example, a structure in which a cylindrical shape of an iron core formed by, for example, impregnation with an adhesive or a resin is maintained may be employed.

<Structure for improving permeability>
In FIG. 13, both end portions (one end portion 11 and the other end portion 12) of the magnetic body 13 are formed so that the shapes of the opposing surfaces in the circumferential direction located at the start and end points of one magnetic body 13 are stepped. An example is shown. FIG. 14 shows an example in which the iron core 7 is formed by stacking a plurality of the magnetic bodies 13 of FIG.

Here, as shown in FIG. 4, when the opposing surface portions (so-called joints) of the magnetic bodies 13 constituting one layer are positioned in the same phase at each lamination position (that is, when viewed in the lamination state, the circumferential direction In the same position), the magnetic permeability of the iron core 7 at a predetermined phase may decrease.

Therefore, as shown in FIG. 14, the magnetic body 13 is configured so that the opposing surface portion 19 in which the one end portion 11 and the other end portion 12 of the yoke portion 8 face each other is on the same plane on the plane including the rotation axis. A plurality may be provided at locations that are not. In other words, a plurality of opposing surface portions 19 in which the one end portion 11 and the other end portion 12 in the circumferential direction of the yoke portion 8 face each other may be provided at different positions in the circumferential direction. The magnetic body 13 is also provided with opposing surface portions 20 that are close to each other in the axial direction.

Specifically, a protruding portion 11 a protruding in the circumferential direction is formed at one end portion 11 of the magnetic body 13, and similarly, protruding at the other end portion 12 of the magnetic body 13 in the circumferential direction. A protruding portion 12a is formed. Here, the protruding portion 11a of the one end portion 11 and the protruding portion 12a of the other end portion 12 are formed so as to protrude in opposite directions, and the positions in the axial direction are staggered. Therefore, in the magnetic body 13, the opposing surface portion 19 where the protruding portion 11a of the one end portion 11 and the other end portion 12 face each other and the opposing surface portion 19 where the protruding portion 12a of the other end portion 12 faces each other in the circumferential direction. It is provided at a different position. Further, the magnetic body 13 is formed with an opposing surface portion 20 in which the protruding portion 11a of the one end portion 11 and the protruding portion 12a of the other end portion 12 face each other in the axial direction, and the protruding portion 11a and the protruding portion 12a are , Close to the axial direction.

By the way, when the planar magnetic body 13 is formed into an arc shape, it is impossible to form a shape in which the opposing surfaces in the circumferential direction interfere with each other. For this reason, a gap (circumferential gap) may be generated between the start point and the end point of the arc due to the dimensional tolerance of the magnetic body 13. There is a possibility that the magnetic permeability is lowered by the circumferential gap.

On the other hand, it is easy to eliminate or reduce the gap in the axially facing surface portion 20 in FIG. Therefore, when the magnetic flux passes through the axially facing surface portion 20 in which the air gap is eliminated or reduced, the decrease in the magnetic permeability due to the circumferential air gap can be mitigated.

Although not shown, either or both of the circumferential surface and the axial direction facing surface portion may be, for example, an inclined facing surface portion or a curved surface. That is, the shape of the protrusion part 11a of the one end part 11 and the protrusion part 12a of the other end part 12 is not restricted to these.

As shown in FIGS. 15 and 16, the opposing surface portions 19 of the laminated magnetic bodies 13 may be arranged in different phases depending on the laminated radial positions. In other words, among the plurality of magnetic bodies 13 arranged concentrically, the facing surface portion 19 of the first magnetic body 13a and the facing surface portion 19 of the second magnetic body 13b are formed at different positions in the circumferential direction. Has been. In this case, the permeability can be improved as compared with an iron core or the like in which the opposing surface portions 19 are arranged in the same phase.

As shown in FIGS. 13 and 14, when the shape of the circumferentially opposed surfaces located at the start and end points of the magnetic body 13 is a stepped shape, the first magnetic body 13 a is opposed to the first magnetic body 13 a. When the surface portion 19 and the facing surface portion 19 of the second magnetic body 13b are formed at different positions in the circumferential direction, it is only necessary that at least the facing surface portion 19 of the magnetic body 13 on the radially outermost periphery is welded.

Each embodiment shows an example in which each shape of a plurality of magnetic bodies 13 to be stacked gradually changes in the stacking direction, which is the radial direction of the iron core. For example, a plurality of magnetic bodies having the same shape are stacked and stacked. It is good also as a structure where the shape of 13 changes to step shape. That is, when viewed from the front, the radial direction of the magnetic pole portion 9 is not a straight line but is stepped. According to this step-like structure, the gap between the circumferential joints when the magnetic body 13 is formed into a cylindrical shape increases, which is disadvantageous in terms of performance. There are fewer types of shapes. For this reason, the freedom degree in manufacture improves, for example, the kind of punching type | molds of the magnetic body 13 can be reduced. The rotor may be a magnetic body integrally having a yoke part and a magnetic pole part.

<Application example of electric motor>
FIG. 17 shows a simplified example of a case where the device 6 using the axial gap type electric motor according to any of the above embodiments is an electric linear actuator. A linear motion mechanism 101 is installed coaxially with the axial gap type electric motor M shown in FIG. The linear motion mechanism 101 includes a ball screw mechanism that is rotationally driven by the rotary shaft 5 of the electric motor M, and converts the rotational motion of the electric motor M into linear motion of the linear motion portion 102. The motor-using device 6 that is the electric linear motion actuator is used, for example, in an electric brake device for braking an automobile wheel, and the linear motion portion 102 is in contact with a brake rotor 103 provided on the wheel of the automobile. It is used for advancing and retracting driving of the friction pad 104 to be separated.

According to this electric linear actuator, since the axial gap type electric motor M is provided, it is possible to realize an electric brake device that enables high torque in a small space. For this reason, the versatility which mounts an electric brake device in a vehicle can be improved. In addition, as described above, the iron core 7 of the electric motor M can be easily and accurately manufactured, and the manufacturing cost can be reduced. Therefore, the cost of the entire motor-using device can be reduced.

As described above, the preferred embodiments have been described with reference to the drawings, but various additions, modifications, and deletions are possible without departing from the spirit of the present invention. Therefore, such a thing is also included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Stator 3 ... Rotor 5 ... Rotating shaft 7 ... Iron core 8 ... Relay part 9 ... Magnetic pole part 11 ... One end part 11a ... Projection part 12 ... Other end part 12a ... Projection part 13 ... Magnetic body 13a ... 1st magnetic body 13b ... 2nd magnetic body 17 ... Holding member 18 ... Welded

part

19, 20 ... Opposite surface part

Claims

A housing, a stator statically held by the housing, and a rotor rotatably supported by the stator, wherein the stator and the rotor are arranged on a rotating shaft of the rotor. An axial gap type electric motor facing the direction,
One or both of the stator and the rotor are
A yoke having a yoke portion extending in a circumferential direction of the rotating shaft and a plurality of magnetic pole portions protruding from the yoke portion in the axial direction of the rotating shaft and arranged in the circumferential direction of the rotating shaft;
The iron core has a cylindrical shape in which one end portion and the other end portion in the circumferential direction of the yoke portion are close to each other, and integrally includes a portion constituting the yoke portion and a portion constituting the magnetic pole portion. An electric motor in which a plurality of magnetic bodies are arranged concentrically.
The electric motor according to claim 1, wherein the magnetic body has a facing surface portion in which one end portion and the other end portion in the circumferential direction of the yoke portion face each other.
The said opposing surface part is an electric motor provided with two or more in the position where the said circumferential direction differs.
3. The electric motor according to claim 2, wherein the one end and the other end have a protrusion protruding in a circumferential direction, and the protrusion at the one end and the protrusion at the other end are in the axial direction. Electric motors that are close to each other.
The electric motor according to any one of claims 1 to 3,
The magnetic body has a facing surface portion in which one end portion and the other end portion in the circumferential direction of the yoke portion face each other.
The electric motor formed in the position where the opposing surface part of the 1st magnetic body of the said several magnetic body and the opposing surface part of the 2nd magnetic body among the said several magnetic bodies differ in the circumferential direction.
The electric motor according to any one of claims 1 to 4, further comprising an annular holding member that holds an outer periphery of an iron core including the plurality of magnetic bodies.
6. The electric motor according to claim 1, wherein the magnetic body includes a welded portion in which a portion adjacent to one end and the other end of the yoke portion is welded. .
A method for manufacturing an electric motor according to any one of claims 1 to 6,
An electric motor comprising: a laminating process for laminating a plurality of thin plate-like magnetic bodies; and a bending molding process for forming the iron core by bending the plurality of magnetic bodies laminated in the laminating process into a cylindrical shape and concentrically. Production method.