JP2013126281A - Method for manufacturing field element, and end plate for field element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a field element, which can suppress magnetic unevenness of a permanent magnet.SOLUTION: The method for manufacturing the field element comprises: a first step of storing a hard magnetic body 11 which is made to be a permanent magnet by magnetization, in at least one of magnet storage holes 21; a second step of inserting a soft magnetic body 30 in a first cavity part 22 corresponding to the hard magnetic body 11; a third step of forming the permanent magnet by magnetizing the hard magnetic body 11 from a side of the soft magnetic body 30 after carrying out the first step and the second step; and a step of removing the soft magnetic body 30 after carrying out the third step.

Description

  The present invention relates to a method for manufacturing a field element and an end plate for the field element, and more particularly to a technique for forming a permanent magnet by magnetizing a hard magnetic body in a state where the hard magnetic body is stored in a field element core. .

  Patent Documents 1 and 2 describe a rotor. The rotor is a so-called embedded permanent magnet rotor in which a permanent magnet is embedded in a rotor core. The rotor core has, for example, a cylindrical shape, and an outer peripheral surface thereof and a permanent magnet face each other in a radial direction centering on the rotation axis. In the rotor core, a gap is formed between the outer peripheral surface and the permanent magnet. The air gap of Patent Document 1 is provided at both ends of the permanent magnet, and prevents the magnetic flux from being short-circuited by the permanent magnet. The air gap in Patent Document 2 is provided at the opposite end of the permanent magnet to the rotational direction, and increases the magnetic flux density on the rotational direction side.

  Patent Document 3 describes a technique for magnetizing a permanent magnet of a motor.

JP 2001-268873 A JP 2001-197694 A Japanese Patent Laid-Open No. 10-14180

  Consider the case where the rotors of Patent Documents 1 and 2 are manufactured by the following procedure. That is, the hard magnetic material is stored in the rotor core, and in this state, the hard magnetic material is magnetized from the outer peripheral side to form a permanent magnet. In this case, since the magnetic flux for magnetization flows through the hard magnetic body through the air gap, the magnetic flux for magnetization does not easily flow through the portion of the hard magnetic body that faces the air gap in the radial direction. This can cause uneven magnetization of the permanent magnet.

  Then, an object of this invention is to provide the manufacturing method of the field element which can suppress the magnetization nonuniformity of a permanent magnet.

  A first aspect of the method of manufacturing a field element according to the present invention includes a plurality of permanent magnets having a field magnetic flux generating surface (10a) arranged in an annular shape around the rotation axis (P) and generating a field magnetic flux (10a). 10), a plurality of storage holes (21) in which the permanent magnets are stored, a first magnetic pole surface and a second magnetic pole surface that face the plurality of permanent magnets in a radial direction around the rotation axis and have different polarities. The magnetic pole surface has side surfaces (25) alternately formed in the circumferential direction around the rotation axis by the field magnetic flux, and a plurality of air gaps (26), each of the air gaps Between the first straight lines (A1, A2) passing through both ends of the magnetic flux generating surface in the circumferential direction, the surface is on the permanent magnet side in the circumferential direction and in the region (R1) on the side surface side in the radial direction. A first air gap portion (22), and each of the first straight lines is located on a boundary between the first magnetic pole surface and the second magnetic pole surface. A field element manufacturing method comprising a field element core (20) parallel to the radial direction at a boundary, wherein at least one of the storage holes is a hard element that becomes the permanent magnet by magnetization. A first step (S1) for storing the magnetic body (11), a second step (S2) for inserting a soft magnetic body (30) into the first gap portion corresponding to the hard magnetic body, and the first A third step (S3) for forming the permanent magnet by magnetizing the hard magnetic material from the soft magnetic material side after the step and the second step, and after the third step, And a fourth step (S4) for removing the magnetic body.

  A second aspect of the field element manufacturing method according to the present invention is the field element manufacturing method according to the first aspect, wherein the gap (26) is provided outside the region (R1). A second gap portion (23) into which the soft magnetic body (30) is not inserted, and the second gap portion extends from the end side in the circumferential direction of the hard magnetic body (11) to the side surface (25). It extends along the radial direction.

  In a third aspect of the method for producing a field element according to the present invention, the first gap portion (22) and the second gap portion (23) are provided apart from each other in the circumferential direction.

  A fourth aspect of the method for manufacturing a field element according to the present invention is a method for manufacturing a field element according to any one of the first to third aspects, wherein in the first step (S1), The hard magnetic body (11) is inserted into all the storage holes (21), and the soft magnetic body (30) is inserted into all the first gap portions (22) in the second step (S2), In the third step (S3), a magnetic field for magnetization is applied to all the hard magnetic bodies (11) in parallel, and in the fourth step (S4), all the soft magnetic bodies are removed. .

  A fifth aspect of the field element manufacturing method according to the present invention is the field element manufacturing method according to any one of the first to fourth aspects, wherein in the first step, the first gap The soft magnetic body (30) is inserted into at least two of the portions (22), and in the second step (S2), at least two of the soft magnetic bodies are connected to one end side of the rotating shaft (P). In a state where they are connected to each other by (40), they are inserted into the first gap portion along the rotation axis (P).

  A sixth aspect of the method for manufacturing a field element according to the present invention is the method for manufacturing a field element according to the fifth aspect, wherein the connecting member (40) is non-magnetic.

  According to a seventh aspect of the field element manufacturing method of the present invention, there is provided the field element manufacturing method according to the fifth aspect, wherein the connecting member (40) has magnetism, and the third step ( In S3), the connecting member (40) and the field element core (20) are separated from each other in the axial direction along the rotation axis (P).

  An eighth aspect of the method for manufacturing a field element according to the present invention is the method for manufacturing a field element according to the seventh aspect, wherein the connecting member (40) has first and second magnetic properties. The first connecting portion is inserted into the first gap portion (22) corresponding to the permanent magnet (10) that forms the first magnetic pole surface on the side surface. The soft magnetic body (30) is coupled, and the second coupling portion is inserted into the first gap portion corresponding to the permanent magnet that forms the second magnetic pole surface on the side surface. In the third step (S3), the first connecting portion and the second connecting portion are magnetically separated from each other.

  A ninth aspect of the method for manufacturing a field element according to the present invention is the method for manufacturing a field element according to the eighth aspect, wherein in the second step (S2), the first connecting portion (41 ) And the soft magnetic body connected by the second connecting portion (42) are opposite to each other with respect to the rotating shaft with respect to the field element core (20). Inserted from the side.

  A tenth aspect of a field element manufacturing method according to the present invention is a field element manufacturing method according to a seventh aspect, wherein in the second step (S2), the first connecting portion (41 ) And the soft magnetic body connected by the second connecting portion (42) are the same with respect to the field element core (20) with respect to the rotation axis. Inserted from the side.

  An eleventh aspect of a method for manufacturing a field element according to the present invention is the method for manufacturing a field element according to the tenth aspect, wherein the first and second steps are performed before the second step. The connecting portions (41, 42) are integrally molded with resin.

  A twelfth aspect of a method for manufacturing a field element according to the present invention is a method for manufacturing a field element according to any one of the first to eleventh aspects, wherein the second step (S2) is not performed. And a fifth step (S5, S6) of attaching an end plate (50) to at least one end side of the field element core (20) in the axial direction along the rotation axis (P). Is formed with a through hole (51) passing through itself in the axial direction at a position corresponding to the first gap portion (22).

  A thirteenth aspect of a method for manufacturing a field element according to the present invention is a method for manufacturing a field element according to any one of the first to twelfth aspects, wherein before the execution of the third step, A sixth step of attaching the field element core to a machine element driven by a field element, the machine element having a surface facing the field element core in an axial direction along the rotation axis; An insertion hole (71) is formed in the surface at a position corresponding to the first gap portion (22), and when the field element core is attached to the machine element in the sixth step, the first gap is formed. The soft magnetic material is inserted and fixed in the insertion hole through the portion.

  A fourteenth aspect of a method for producing a field element according to the present invention is a method for producing a field element according to any one of the first to thirteenth aspects, wherein the soft magnetic body (30) is the field. It is made of the same material as the magnetic core (20).

  A fifteenth aspect of a method for manufacturing a field element according to the present invention is a method for manufacturing a field element according to any one of the first to fourteenth aspects, wherein the soft magnetic body (30) is It has the some steel plate laminated | stacked along the circumferential direction.

  A sixteenth aspect of a method for manufacturing a field element according to the present invention is a method for manufacturing a field element according to any one of the first to fifteenth aspects, wherein the circumferential direction of the permanent magnet (10) is The coercive force at both ends in is higher than the center in the circumferential direction.

  A field element manufacturing method according to a seventeenth aspect of the present invention is a field element manufacturing method according to the sixteenth aspect, wherein the permanent magnet (10) is formed by grain boundary diffusion of heavy rare earths. Is done.

  The first aspect of the end plate for a field element according to the present invention is arranged in an annular shape around the rotation axis (P), and the first and second magnetic poles, which are alternately different, are centered on the rotation axis. A plurality of permanent magnets (10) generated in the radial direction, a plurality of storage holes (21) in which the permanent magnets are stored, and a plurality of gaps (22) are formed, each of the gaps is Each of the first straight lines exists in a region (R1) on the permanent magnet side between the first straight lines (A1, A2) passing through both ends of each of the permanent magnets in the circumferential direction around the rotation axis. Is a field element core parallel to a second straight line (B1, B2) passing through a point closest to itself among the midpoints between the permanent magnets adjacent in the circumferential direction and the rotation axis An end plate (50) attached to a field element comprising (20), a main body part (52) contacting the field element core in the axial direction along the rotation axis, and the main body part (52 ) And a through hole (51) penetrating the main body portion in the axial direction at a position corresponding to the gap.

  According to the first aspect of the method for manufacturing a field element according to the present invention, it is possible to suppress the uneven magnetization of the permanent magnet due to the magnetization with the gap remaining in the first gap portion.

  According to the second aspect of the method for manufacturing a field element according to the present invention, the second gap portion guides the magnetic flux for magnetization toward the hard magnetic material, so that the efficiency of magnetization can be improved.

  According to the third aspect of the method for manufacturing a field element according to the present invention, a part of the field element core is interposed between the first gap portion and the second gap portion. The strength as can be improved.

  According to the 4th aspect of the manufacturing method of the field element concerning this invention, it does not repeat the 1st process to the 4th process for every permanent magnet, but performs the 1st process to the 4th process collectively. Therefore, the period required for the magnetization process can be shortened.

  According to the fifth aspect of the method of manufacturing a field element according to the present invention, a plurality of soft magnetic bodies can be inserted into a plurality of gaps at a time, and workability can be improved. Therefore, it is useful in the second step when magnetizing a plurality of permanent magnets, for example, the second step in the manufacturing method of claim 4.

  According to the sixth aspect of the field element manufacturing method of the present invention, the third step in the case of magnetizing a plurality of hard magnetic bodies in parallel to form the first and second polarity permanent magnets. For example, in the third step of the manufacturing method according to claim 4, even if different magnetic fields are applied to the plurality of hard magnetic bodies, the magnetic flux can be prevented from being short-circuited via the connecting member. Therefore, a decrease in magnetization efficiency can be suppressed.

  According to the seventh aspect of the field element manufacturing method of the present invention, the third step in the case of magnetizing a plurality of hard magnetic bodies in parallel to form the first and second polarity permanent magnets. For example, in the third step of the manufacturing method of claim 4, even when different magnetic fields are applied to the plurality of hard magnetic bodies, it is possible to suppress a short circuit of the magnetic flux through the connecting member. Therefore, a decrease in magnetization efficiency can be suppressed.

  According to the 8th aspect of the manufacturing method of the field element concerning this invention, it can further suppress that a magnetic flux short-circuits via a connection member.

  According to the ninth aspect of the field element manufacturing method of the present invention, the first and second connecting portions do not interfere with each other in the second step. A simple structure can be employed without employing a complicated structure that can avoid interference.

  According to the tenth aspect of the field element manufacturing method of the present invention, the soft magnetic bodies respectively connected to the first and second connecting portions in the second step are opposite to the field element core. Even in a work space that cannot be inserted from the side, a soft magnetic material can be inserted. In other words, the selectivity of the work space can be improved.

  According to the eleventh aspect of the method of manufacturing a field element according to the present invention, the first and second connecting portions are fixed to each other by the resin, so that the soft magnetism connected by the first and second connecting portions. Easy to insert body at once.

  According to the twelfth aspect of the field element manufacturing method of the present invention, the soft magnetic material can be inserted into and removed from the gap with the end plate attached to the field element core.

  According to the thirteenth aspect of the method for manufacturing a field element according to the present invention, since the soft magnetic body is inserted into the first gap portion and the insertion hole, the position of the field element core relative to the mechanical element can be easily set. I can decide. Therefore, workability can be improved when magnetizing a field element core attached to a machine element.

  According to the fourteenth aspect of the method for producing a field element according to the present invention, the uneven magnetization can be further suppressed.

  According to the fifteenth aspect of the field element manufacturing method of the present invention, since the magnetic flux for magnetization flows along the laminated surface of the steel plates in the fourth step, it is difficult to inhibit the flow of the magnetic flux for magnetization. .

  According to the sixteenth aspect of the field element manufacturing method of the present invention, demagnetization when a reverse magnetic field is applied to both ends of the permanent magnet in the field element can be suppressed. Also, both ends of the hard magnetic material are easily magnetized.

  According to the seventeenth aspect of the method for producing a field element according to the present invention, the coercive force can be increased with a small amount of heavy rare earth.

  According to the 1st aspect of the end plate for field elements concerning this invention, it contributes to execution of the manufacturing method of the field element concerning a 13th aspect.

It is a figure which shows an example of a notional structure of the field element in a cross section perpendicular | vertical to a rotating shaft. It is a figure which shows an example of the manufacturing method of a field element. It is a perspective view which shows an example of a mode that a soft magnetic body is inserted in the core for field elements. It is a figure which shows an example of the mode of the magnetization in a cross section perpendicular | vertical to a rotating shaft. It is a figure which shows an example of the mode in the case of the magnetization in a cross section perpendicular | vertical to a rotating shaft. It is a figure which shows an example of the mode in the case of the magnetization in a cross section perpendicular | vertical to a rotating shaft. It is a figure which shows an example of the mode in the case of the magnetization in a cross section perpendicular | vertical to a rotating shaft. It is a perspective view which shows an example of a mode that a soft magnetic body is inserted in the core for field elements. It is a figure which shows an example of the state by which the soft-magnetic body was inserted in the core for field elements in the cross section containing a rotating shaft. It is a perspective view which shows an example of a mode that a soft magnetic body is inserted in the core for field elements. It is a perspective view which shows an example of a mode that a soft magnetic body is inserted in the core for field elements. It is a figure which shows an example of the manufacturing method of a field element. It is a perspective view which combines an example of a mode that an end plate is attached to a core for field elements, and a mode of inserting a soft magnetic material. It is a figure which shows an example of the manufacturing method of a field element. It is a figure which shows an example of the mode of the magnetization in the cross section containing a rotating shaft.

First embodiment.
<Example of configuration of field element 1>
As illustrated in FIG. 1, the field element 1 includes a plurality of permanent magnets 10 and a field element core 20. In the following, the radial direction around the rotation axis P is simply called the radial direction, the circumferential direction around the rotation axis P is simply called the circumferential direction, and the direction extending along the rotation axis P is called the axial direction. .

  The plurality of permanent magnets 10 are, for example, rare earth magnets (for example, rare earth magnets mainly composed of neodymium, iron, and boron), and are arranged annularly around the rotation axis P. Each permanent magnet 10 has a pair of surfaces 10a and 10b opposed to each other in the radial direction. Here, the surface 10a is located on the opposite side of the rotation axis P with respect to the surface 10b. In the illustration of FIG. 1, each permanent magnet 10 has a V-shape that opens on the side opposite to the rotation axis P (hereinafter also referred to as the outer peripheral side) when viewed along the axial direction. However, each permanent magnet 10 is not necessarily arranged in the shape shown in FIG. Each permanent magnet 10 may have a rectangular shape when viewed in the axial direction, for example, and has a V shape that opens to the rotating shaft P side (hereinafter also referred to as the inner peripheral side), or the outer peripheral side or inner peripheral side. You may have the circular arc shape opened to the side. Moreover, it is good also as a V-shape with two rectangular magnets.

  The field element core 20 is formed of a soft magnetic material (for example, iron). In the illustration of FIG. 1, the field element core 20 has, for example, a cylindrical shape with the rotation axis P as the center. Therefore, in the illustration of FIG. 1, the side surface (outer peripheral surface) 25 of the field element core 20 has a cylindrical shape. The field element core 20 is formed with a plurality of magnet storage holes 21 for storing the plurality of permanent magnets 10. The side surface 25 faces the permanent magnet 10 in the radial direction, and the plurality of permanent magnets 10 form magnetic pole surfaces 25 a and 25 b on the side surface 25. The magnetic pole surfaces 25a and 25b have different polarities and are alternately arranged in the circumferential direction.

  In the illustration of FIG. 1, six permanent magnets 10 are shown, and a so-called six-pole field element 1 is shown. The six permanent magnets 10 are arranged with the surfaces 10 a having different polarities alternately in the circumferential direction facing the side surface 25. As a result, six magnetic pole surfaces are formed on the side surface 25. However, the present invention is not limited to this, and the field element 1 may be a field element having 4 poles or less or 8 poles or more. In the illustration of FIG. 1, one permanent magnet 10 forms one magnetic pole surface, but a plurality of permanent magnets may form one magnetic pole surface. In other words, each of the permanent magnets 10 may be divided into a plurality of permanent magnets 10.

  In the illustration of FIG. 1, the field element core 20 is formed with a shaft hole 27 in a region including the rotation axis P. The shaft hole 27 penetrates the field element core 20 in the axial direction. A shaft (not shown) is fitted into the shaft hole 27, whereby the field element 1 is fixed to the shaft. That is, FIG. 1 illustrates a field element 1 that functions as a rotor. However, the field element 1 is not necessarily required to function as a rotor, and may function as a stator. Even if the field element 1 functions as a rotor, for example, when end plates are provided on both sides in the axial direction of the field element core 20 and different shafts are attached to the end plates, the shafts are used for the field elements. Since the core 20 is not penetrated, the shaft hole 27 is not necessary.

  In the illustration of FIG. 1, a through hole 28 is formed in the field element core 20 on the inner peripheral side of the permanent magnet 10. For example, the through hole 28 is annularly arranged around the rotation axis P, and penetrates the field element core 20 in the axial direction. For example, the through holes 28 have rivets penetrated together with end plates attached to both sides of the field element core 20 to fix the both end plates to the field element core 20. The through hole 28 is not an essential requirement.

  The field element core 20 may have, for example, steel plates (for example, steel plates such as electromagnetic steel plates and amorphous steel plates) stacked in the axial direction. Thereby, the electrical resistance in the axial direction can be increased, and as a result, the eddy current caused by the magnetic flux flowing through the field element core 20 can be reduced. The field element core 20 may be formed of a dust core (eg, an iron-based dust core or a ferrite-based dust core) that is intentionally formed to include an insulator. This can also increase the electrical resistance, thereby reducing eddy currents.

  A rotating electric machine is realized by disposing an armature (not shown) on the outer peripheral side of the field element 1. In this rotating electrical machine, the side surface 25 faces the armature through the air gap. Thereby, the field element 1 can supply field magnetic flux to an armature. Then, when the armature applies a rotating magnetic field to the field element 1, the armature and the field element rotate relatively around the rotation axis P. In addition, it can grasp | ascertain that the surface located in the armature side among surface 10a, 10b is the field magnetic flux generation | occurrence | production surface which generates a field magnetic flux. In the illustration of FIG. 1, the surface 10a corresponds to a field magnetic flux generating surface.

  In the illustration of FIG. 1, the armature is disposed on the outer peripheral side of the field element 1, but the armature may be disposed on the inner peripheral side of the field element 1. In this case, the field element core 20 has a ring shape, and the permanent magnet 10 is disposed on the side opposite to the rotation axis P (that is, on the outer peripheral side) relative to the inner peripheral surface of the field element core 20. The magnetic pole surface is formed on the inner peripheral surface. That is, the inner peripheral surface functions as the side surface 25. Then, the side surface 25 faces the armature via the air gap. In the following description, a structure in which an armature is disposed on the outer peripheral side of the field element 1 will be described. However, if the side surface 25 is grasped as an inner peripheral surface, a field element in which the armature is disposed on the inner peripheral side will be described. The following explanation is valid for 1.

  An air gap 26 is formed in the field element core 20. The air gap 26 is provided corresponding to the magnetic pole surface, and has at least a first air gap portion 22 existing in a region R1 described below. The region R1 is a region sandwiched by the straight lines A1 and A2 passing through both ends in the circumferential direction of the field magnetic flux generation surface (surface 10a) of the permanent magnet 10, and is on the permanent magnet 10 side in the circumferential direction and is permanent in the radial direction. 10 is a region on the side surface 25 side. The both ends in the circumferential direction of the field magnetic flux generation surface referred to here are both ends of the entire field magnetic flux generation surface belonging to each magnetic pole surface. That is, when one magnetic pole surface is formed by a plurality of permanent magnets, the both ends are both ends when a plurality of field magnetic flux generating surfaces belonging to the plurality of permanent magnets are grasped as one.

  The straight line A1 is parallel to the radial direction (the straight line B1 in the figure) at the boundary closest to itself among the boundaries between the magnetic pole surfaces 25a and 25b (so-called inter-polarity). The straight line A2 is parallel to the radial direction (the straight line B2 in the figure) at the boundary closest to itself among the boundaries.

  In the illustration of FIG. 1, two first gap portions 22 are formed corresponding to the magnetic pole surfaces 25a and 25b, and these two first gap portions 22 are formed near both sides in the circumferential direction in the region R1. ing. Each first gap portion 22 extends in the circumferential direction, and has a shape that tapers toward the center (magnetic pole center) in the circumferential direction of the magnetic pole surface corresponding to itself. Thereby, for example, the shape of the magnetic flux density generated on the side surface 25 can be made closer to a sine wave shape.

  In the illustration of FIG. 1, the space | gap 26 has the 2nd space | gap part 23 outside area | region R1. The second gap portion 23 extends along the radial direction from both sides in the circumferential direction of the permanent magnet 10 toward the side surface 25. These second gap portions 23 can prevent the magnetic flux from being short-circuited between the surfaces 10a and 10b.

  In the illustration of FIG. 1, the 1st space | gap part 22 and the 2nd space | gap part 23 are mutually spaced apart in the circumferential direction. As a result, part of the field element core 20 is interposed between the first gap portion 22 and the second gap portion 23, so that the strength of the field element core 20 can be improved. Furthermore, the harmonic component of the magnetic flux can be reduced by the magnetic flux passing between the first gap portion 22 and the second gap portion 23.

  In the illustration of FIG. 1, the second gap portion 23 and the magnet storage hole 21 are continuous. However, the present invention is not limited thereto, and the second gap portion 23 and the magnet storage hole 21 may be separated from each other. If a part of the field element core 20 is interposed between the second gap portion 23 and the magnet housing hole 21, the strength of the field element core 20 can be improved.

<Example of Method for Manufacturing Field Element 1>
As illustrated in FIG. 2, in step S <b> 1, the hard magnetic material 11 that is magnetized and becomes the permanent magnet 10 is stored in at least one of the magnet storage holes 21 (see also FIG. 4). As a more detailed example, the hard magnetic body 11 is inserted along the axial direction into all the magnet storage holes 21.

  Next, in step S <b> 2, as illustrated in FIG. 3, the soft magnetic body 30 is inserted into the first gap portion 22 of the stored hard magnetic body 11. In the illustration of FIG. 3, it is assumed that the hard magnetic body 11 is stored in all the magnet storage holes 21. Therefore, in the illustration of FIG. 3, the soft magnetic body 30 is inserted in all the first gap portions 22 along the axial direction. In FIG. 3, a part of the soft magnetic body 30 on the back side of the drawing is omitted for simplification of illustration.

  Further, step S2 is not necessarily executed after step S1, and may be executed prior to step S1.

  Next, in step S3, as illustrated in FIG. 4, the hard magnetic body 11 is magnetized from the soft magnetic body 30 side. In the illustration of FIG. 4, a magnetizer 80 that can magnetize the hard magnetic bodies 11 stored in all the magnet storage holes 21 in parallel is shown. In other words, the magnetizer 80 can collectively apply a magnetic field for magnetization to all the hard magnetic bodies 11. For example, in the magnetizer 80, teeth are arranged corresponding to all the hard magnetic bodies 11, windings are wound around these teeth, and these teeth are mutually connected by a back yoke on the side opposite to the field element core 20. Connected. Then, by applying an appropriate current to the windings, a magnetic field for magnetization can be collectively applied to all the hard magnetic bodies 11.

  The hard magnetic bodies 11 do not necessarily have to be magnetized in parallel, and at least one hard magnetic body 11 may be magnetized. For example, you may repeat step S1-S3 for every number of the hard magnetic bodies 11. FIG. However, if a plurality of hard magnetic bodies 11 are magnetized in parallel, the time required for magnetization can be reduced compared to the case where the hard magnetic bodies 11 are individually magnetized in different time zones.

  Next, in step S <b> 4, the soft magnetic body 30 is removed from the field element core 20. Thereby, the 1st space | gap part 22 as the field element 1 can be functioned.

  According to the method of manufacturing the field element, the hard magnetic body 11 is magnetized with the soft magnetic body 30 inserted in the first gap portion 22. Since the first gap portion 22 functions as a magnetic resistance that inhibits the flow of magnetic flux for magnetization, when the hard magnetic body 11 is magnetized without the soft magnetic body 30 inserted, the first of the hard magnetic bodies 11 It is difficult for the magnetic flux for magnetization to flow through the portion 111 facing the gap portion 22 in the substantially radial direction. On the other hand, according to this manufacturing method, since the soft magnetic body 30 is inserted into the first gap portion 22, it is possible to suppress the reduction of the magnetic flux flowing to the portion 111 by the first gap portion 22, and to magnetize the portion 111. The shortage can be suppressed. In other words, uneven magnetization can be suppressed.

  1 to 4, the soft magnetic body 30 has substantially the same shape as the first gap portion 22 when viewed along the axial direction. However, the present invention is not limited to this, and the soft magnetic body 30 may have any shape that can be inserted into the first gap portion 22. If the soft magnetic body 30 exists in the first gap portion 22, the cross-sectional area occupied by air in the first gap portion 22 can be reduced, so that the magnetic resistance of the first gap portion 22 can be reduced. is there. Of course, it is desirable that the first gap portion 22 and the soft magnetic body 30 have substantially the same shape because the magnetic resistance in the first gap portion 22 can be minimized.

  In step S3, it is desirable that the magnetization is performed in a state where the soft magnetic material is not inserted into the second gap portion 23. This is because when a soft magnetic material is inserted also into the second gap portion 23, the magnetic flux for magnetization easily bypasses the hard magnetic material 11 via the soft magnetic material. More specifically, referring to FIG. 4, the magnetic flux for magnetization flowing from one tooth of the magnetizer 80 is inserted into the soft magnetic body 30 and the second gap portion 23 without passing through the hard magnetic body 11. It is easy to flow to the next tooth through the soft magnetic material. On the other hand, when the hard magnetic body 11 is magnetized in a state where no soft magnetic material is inserted into the second gap portion 23, the second gap portion 23 functioning as a magnetic resistance causes such magnetic flux to be transferred to the hard magnetic body 11. Can lead.

  From the viewpoint of inducing the above-described action of the second gap portion 23, a soft magnetic material may be inserted into a part of the second gap portion 23. In short, a portion of the second gap portion 23 that is not inserted by the soft magnetic body 30 only needs to extend in the radial direction from both end sides of the permanent magnet 10 to the side surface 25.

<Another example of field element>
The field element core 20 according to the example of FIGS. 5 and 6 differs from the field element core 20 according to the example of FIG. 5 and 6 show the hard magnetic body 11 inserted into only one of the magnet storage holes 21 and the soft magnetic body 30 inserted into the gap 26 corresponding to the hard magnetic body 11. However, this does not mean that only one of the hard magnetic bodies 11 is magnetized, and the number of hard magnetic bodies 11 magnetized at a time in step S3 is arbitrary.

  5 and 6, the first gap portion 22 and the second gap portion 23 are continuous with each other in the circumferential direction. In other words, the air gap 26 extends in the circumferential direction into the region R <b> 1 while extending in the radial direction from both ends in the circumferential direction of the permanent magnet 10 (hard magnetic body 11) toward the side surface 25. More specifically, for example, the gap 26 in FIG. 5 has a shape obtained by continuously connecting the first gap portion 22 and the second gap portion 23 in FIG. 1 in the circumferential direction. In the air gap 26 of FIG. 6, the first air gap portion 22 extends in the circumferential direction while maintaining the radial width substantially constant in the region R1.

  As illustrated in FIG. 5, the soft magnetic body 30 may be inserted into the gap 26 in the region R <b> 1, but may protrude beyond the region R <b> 1. Further, as illustrated in FIG. 6, the soft magnetic body 30 may be inserted into only a part of the gap 26 in the region R1. The first gap portion 22 here is a portion that is inserted into the soft magnetic body 30 in the region R1, and the second gap portion 23 here is a portion that is not inserted into the soft magnetic body 30 outside the region R1. .

  5 and 6, since the magnetization is performed in the state where the soft magnetic body 30 exists in the region R1 in step S3, uneven magnetization of the permanent magnet 10 can be reduced. Further, magnetization is performed in a state where the second gap portion 23 is not inserted into the soft magnetic body, so that a magnetic flux for magnetization can be guided to the hard magnetic body 11.

<Soft magnetic body 30>
The soft magnetic body 30 is preferably made of the same material as the field element core 20. As a result, even when the first gap portion 22 is substantially filled with the soft magnetic material 30, the uneven magnetization can be further reduced.

  Further, when the field element core 20 includes a plurality of steel plates laminated in the axial direction (for example, a steel plate such as an electromagnetic steel plate and an amorphous steel plate, the same applies hereinafter), the soft magnetic body 30 also includes a plurality of laminated steel plates. Also good. The steel plates constituting the soft magnetic body 30 are laminated in a direction perpendicular to the rotation axis P, for example. More preferably, as illustrated in FIG. 7, the stacking direction is preferably along the substantially circumferential direction. This is because the magnetic flux for magnetization flows along the substantially radial direction in the soft magnetic body 30, so that the magnetic flux flows along the laminated surface of the steel plates, and it is difficult to inhibit the flow of the magnetic flux.

  In the illustration of FIG. 7, although about 10 steel plates constituting the soft magnetic body 30 are shown, the number is arbitrary. However, in terms of aligning the magnetic properties of the soft magnetic body 30 and the field element core 20, the axial thickness of the steel sheet constituting the field element core 20 and the circumference of the steel sheet constituting the soft magnetic body 30 are the same. The thickness in the direction may be equal to each other.

  The soft magnetic body 30 is particularly useful when the first gap portion 22 has a rectangular shape that is long in the circumferential direction when viewed in the axial direction. It is because the soft magnetic body 30 matched with the shape of the 1st space | gap part 22 is realizable by laminating | stacking the steel plate of the same shape in the circumferential direction.

  Further, it is desirable that the steel plates constituting the soft magnetic body 30 are fixed to each other using varnish, adhesion, electrodeposition or the like. This is because the soft magnetic body 30 can be handled integrally.

<Double magnetization>
Referring to FIG. 2, before the execution of step S2, the hard magnetic body 11 is magnetized, and in step S3, the soft magnetic body 30 is inserted into the first gap portion 22, and then the hard magnetic body is again in step S4. Eleven magnetizations may be performed. Or you may magnetize the hard magnetic body 11 again after execution of step S4. In the magnetization before execution of step S2, for example, the vicinity of the center of the magnet is mainly magnetized, and in the magnetization of step S4, for example, the vicinity of the end of the magnet is mainly magnetized.

Second embodiment.
The field element manufacturing method according to the second embodiment is as described in the first embodiment. However, as illustrated in FIG. 8, the soft magnetic bodies 30 are connected to each other by a connecting member 40 on one end side in the axial direction. In the illustration of FIG. 8, the field element core 20 of FIG. 1 and the soft magnetic body 30 corresponding thereto are shown, and all of the soft magnetic bodies 30 inserted into all the first gap portions 22 are shown. The connecting members 40 are connected to each other. Note that the connecting member 40 does not necessarily have to connect all the soft magnetic bodies 30, and may connect at least two or more soft magnetic bodies 30. For example, referring to FIG. 1, only two soft magnetic bodies 30 inserted into two first gap portions 22 existing in the region R1 for one magnetic pole surface may be connected.

  In the example of FIG. 8, the connecting member 40 has a columnar plate-shaped portion 401 and a columnar portion 402 that is fixed to the portion 401 and is concentric with the portion 401 and includes a smaller diameter than the portion 401. And have. An operator can grasp the portion 402 and handle the soft magnetic body 30 as one body. Of course, the shape of the connecting member 40 is not limited to this, and the connecting member 40 may be arbitrary as long as the connecting member 40 connects the soft magnetic body 30 on one end side in the axial direction. For example, the portion 402 can be omitted.

  If the plurality of soft magnetic bodies 30 are connected by the connecting member 40, the plurality of soft magnetic bodies 30 can be collectively inserted into the plurality of first gap portions 22 in step S2. Therefore, workability can be improved. This is particularly useful when the soft magnetic body 30 is inserted into all the first gap portions 22.

  The connecting member 40 is preferably nonmagnetic. Thereby, for example, even if the connecting member 40 is in contact with the field element core 20 on the outer peripheral side and the inner peripheral side of the hard magnetic body 11, a part 81 of the magnetic flux for magnetization passes through the connecting member 40. Flowing around and bypassing the hard magnetic body 11 can be suppressed. Alternatively, for example, even if the connecting member 40 and the field element core 20 are in contact with each other with a width across the plurality of hard magnetic bodies 11 in the circumferential direction, a part 80 of the magnetic flux for magnetization is connected to the connecting member. It is possible to suppress the flow through 40 and bypassing the hard magnetic body 11.

  On the other hand, the connecting member 40 may have magnetism. In this case, as illustrated in FIG. 9, the connecting member 40 and the field element core 20 are separated from each other in the axial direction, and the nonmagnetic portion 90 is interposed between the connecting member 40 and the field element core 20. It is desirable to do. As described above, part of the magnetic flux 80 and 81 can flow from the field element core 20 to the connecting member 40, and these magnetic fluxes can be reduced by the nonmagnetic portion 90. In the illustration of FIG. 9, the nonmagnetic portion 90 is air.

  However, in the embodiment of FIG. 9, a part of the magnetic flux for magnetization flows through the soft magnetic body 30 and the connecting member 40, and can bypass the hard magnetic body 11. Therefore, it is desirable that the connecting member 40 having magnetism connects only the soft magnetic body 30 of the hard magnetic body 11 that is magnetized to the same polarity (see also FIG. 10). Magnetic flux flows so as to connect magnetic poles having different polarities, but does not flow so as to connect magnetic poles of the same polarity. Therefore, by performing the above connection, the magnetic flux for magnetization does not flow between the soft magnetic bodies 30 via the connection member 40.

  In this case, the soft magnetic bodies 30 for the hard magnetic bodies 11 that are magnetized to other polarities need only be separated from each other as in the first embodiment. Alternatively, as illustrated in FIG. 10, these soft magnetic bodies 30 may also be connected to each other. This aspect will be described in detail below.

  The connecting member 40 has connecting portions 41 and 42 having magnetism. The connecting part 41 connects only the soft magnetic body 30 of the hard magnetic body 11 magnetized to the first magnetic pole having the same polarity, and the connecting part 42 is magnetized to the second magnetic pole different in polarity from the first magnetic pole. Only the soft magnetic body 30 of the hard magnetic body 11 is connected. Then, in a state where these soft magnetic bodies 30 are inserted into the first gap portion 22, the connecting portions 41 and 42 are magnetically separated from each other. That is, a nonmagnetic part (for example, air) is interposed between the connecting parts 41 and 42. In the illustration of FIG. 10, the soft magnetic bodies 30 respectively belonging to the coupling portions 41 and 42 are inserted into the first gap portion 22 along the axial direction from the opposite sides to the field element core 20. Therefore, the connecting portions 41 and 42 are arranged on the opposite sides with respect to the field element core 20. A nonmagnetic portion (for example, air) is interposed between the connecting portion 41 and the field element core 20, and a nonmagnetic portion (for example, air) is interposed between the connecting portion 42 and the field element core 20. Intervenes.

  Thereby, the magnetic flux which bypasses the hard magnetic body 11 can be suppressed. And the connection parts 41 and 42 are located in the mutually opposite side with respect to the core 20 for field elements. Therefore, the connecting portions 41 and 42 do not interfere with each other spatially. Therefore, a simple shape can be adopted as the connecting portions 41 and 42. For example, in the illustration of FIG. 10, the connection parts 41 and 42 have a ring-shaped flat plate shape.

  In the illustration of FIG. 11, the connecting portions 41 and 42 are located on the same side with respect to the field element core 20. Thereby, even if it is a case where the soft magnetic body 30 which each belongs to the connection parts 41 and 42 cannot be inserted from the mutually opposite side with respect to the core 20 for field elements, the soft magnetic body 30 can be inserted. In other words, the selectivity of the work space can be improved.

  In the illustration of FIG. 11, the connecting portions 41 and 42 are magnetically separated from each other in the radial direction and the circumferential direction. That is, a nonmagnetic portion (for example, air, the same applies hereinafter) is interposed between them in the radial direction. In the illustration of FIG. 11, the connecting portion 41 is located on the outer peripheral side with respect to the connecting portion 42. Hereinafter, a more detailed example of the shape of the connecting portions 41 and 42 will be described.

  In the illustration of FIG. 11, the connecting portion 41 includes a fixed portion 411 and a connecting portion 412, and the connecting portion 42 includes a fixed portion 421 and a connecting portion 422. The fixed portions 411 and 421 are respectively fixed to one end of the soft magnetic body 30 at positions corresponding to the magnetic pole surfaces 25a and 25b in the circumferential direction. In the illustration of FIG. 11, since the two first gap portions 22 are provided corresponding to the magnetic pole surfaces 25 a and 25 b, the fixed portions 411 and 421 are respectively fixed to one end of the two soft magnetic bodies 30. The fixed portions 411 and 412 are alternately adjacent in the circumferential direction. A nonmagnetic part is interposed between the fixed parts 411 and 412.

  The connection portion 412 connects the fixed portion 411 on the outer peripheral side of the fixed portion 421. A nonmagnetic part is interposed between the connection part 412 and the fixed part 421. The connection portion 422 connects the fixed portion 421 on the inner peripheral side with respect to the fixed portion 411. A nonmagnetic part is interposed between the connection part 422 and the fixed part 411.

  Accordingly, the connecting portions 41 and 42 can be magnetically separated from each other in the radial direction while the connecting portions 41 and 42 are disposed on the same side in the axial direction with respect to the field element core 20. In addition, the connection parts 41 and 42 are not restricted to the aspect of FIG. In short, it is sufficient that the connecting portions 41 and 42 are magnetically separated from each other. For example, the connecting portions 41 and 42 may be magnetically separated in the axial direction.

  Moreover, the connection parts 41 and 42 may be integrally molded with resin. Therefore, it is easy to insert the soft magnetic bodies 30 connected by the connecting portions 41 and 42 at a time. Thereby, workability | operativity can be improved.

  Here, the magnetic separation between the first member and the second member includes that the first member and the second member are connected to each other through a thin portion having magnetism. This thin portion is thin enough to easily saturate the magnetic flux. Even in this case, the magnetic flux flowing between the first member and the second member via the thin portion is reduced.

Third embodiment.
In 3rd Embodiment, the case where an end plate is attached to the one end side in the axial direction of the core 20 for field elements is assumed. FIG. 12 shows an example of a flowchart of the method of manufacturing the field element, and FIG. 13 shows a state where the end plate is attached and a state where the soft magnetic body 30 is inserted.

  The end plate 50 includes a main body 52 that contacts the field element core 20 in the axial direction, and a through hole 51 formed in the main body 52. The main body 52 has, for example, a ring-shaped flat plate shape. The through hole 51 penetrates the main body 52 in the axial direction, and faces the first gap portion 22 in the axial direction in a state where the end plate 50 is attached to the field element core 20. For example, the outline of the through hole 51 seen in the axial direction surrounds the outline of the first gap portion 22 seen in the axial direction.

  The end plate 50 is preferably a non-magnetic material. This is because the magnetic flux of the permanent magnet 10 can be prevented from being short-circuited through the end plate 50 even if it contacts the field element core 20 in the axial direction in the same manner as the connecting member 40. It is also suppressed that the magnetic flux for magnetization at the time of magnetization bypasses the hard magnetic body 11 via the end plate 50.

  In the illustration of FIG. 13, the end plate 55 is attached to the field element core 20 on the side opposite to the end plate 50 in the axial direction. The end plate 55 has, for example, a ring-shaped flat plate shape and does not have the through hole 51. Of course, the end plates 50 may be attached to both sides of the field element core 20. In particular, as shown in FIG. 10, for example, when the soft magnetic body 30 is inserted into the first gap portion 22 from both sides in the axial direction and removed from the first gap portion 22, the end plates 50 are attached to both sides.

  Next, an example of a method for manufacturing the field element 1 will be described. Prior to step S1, the lower end plate 55 is attached to the field element core 20 in step S5. Next, the hard magnetic body 11 is inserted into the magnet storage hole 21 in step S1. Next, the upper end plate 50 is attached to the field element core 20 in step S6. As a result, the hard magnetic body 11 is sandwiched between the end plates 50 and 55 in the axial direction. Therefore, the hard magnetic body 11 can be prevented from coming off from the field element core 20 in the axial direction.

  Next, in step S <b> 2, the soft magnetic body 30 is inserted into the first gap portion 22 through the through hole 51. The subsequent procedure is the same as that of the first embodiment.

  As described above, according to the present end plate 50, the soft magnetic body 30 can be inserted into the first gap portion 22 after the end plate 50 is attached to the field element core 20, and the magnetization is completed. For example, the soft magnetic body 30 can be removed via the through hole 51. In other words, the end plate 50 is suitable for use in the method of manufacturing the field element.

Fourth embodiment.
In the fourth embodiment, as illustrated in FIG. 15, the hard magnetic body 11 is magnetized with the field element core 20 attached to the mechanical element 70 driven by the field element 1. In the fourth embodiment, the field element 1 functions as a rotor. Therefore, the field element 1 is fixed to the shaft 60 belonging to the mechanical element 70. As the field element 1 rotates, the shaft 60 rotates and the mechanical element 70 is driven. In the illustration of FIG. 15, for the sake of simplicity of illustration, a mechanism that rotates as the shaft 60 rotates is omitted.

  The mechanical element 70 is, for example, a compression mechanism, and has a surface 72 as illustrated in FIG. The surface 72 faces the field element core 20 in the axial direction. An insertion hole 71 that opens to the field element core 20 side is formed in the surface 72 at a position facing the first gap portion 22 in the axial direction.

  Next, an example of a method for manufacturing the field element will be described. As illustrated in FIG. 14, for example, before or after execution of step S <b> 1, the field element core 20 is attached to the machine element 70 in step S <b> 7. This is realized by fixing the field element core 20 to the shaft 60 belonging to the mechanical element 70.

  Next, in step S 2, the soft magnetic body 30 is inserted through the first gap portion 22 and inserted into the insertion hole 71 while the field element core 20 is rotated around the shaft 60 and aligned. That is, the soft magnetic body 30 is inserted after the field element core 20 is rotated so that the first gap portion 22 and the through hole 71 face each other in the axial direction. Thereafter, the manufacturing method is the same as that described in the first embodiment, so that repeated description is avoided.

  According to such a manufacturing method, the soft magnetic body 30 is inserted into the first gap portion 22 and the insertion hole 71. Therefore, the rotational position of the field element core 20 with respect to the mechanical element 70 can be easily adjusted. Moreover, when the hard magnetic body 11 is magnetized, the field element core 20 can rotate around the rotation axis P due to the magnetization, and the soft magnetic body 30 suppresses the rotation with respect to the mechanical element 70. it can. Therefore, if the magnetizer 80 is fixed to the mechanical element 70, deficiencies in magnetization due to rotation of the field element core 20 during magnetization in step S3 can be suppressed.

Fifth embodiment.
Since the reverse magnetic field from the armature is concentrated at both ends in the circumferential direction of the permanent magnet 10, the permanent magnet 10 is likely to be demagnetized at both ends. Therefore, in the fifth embodiment, the coercive force of the permanent magnet 10 is higher at both ends than the center in the circumferential direction. Thereby, the demagnetization which is easy to occur at both ends of the permanent magnet can be suppressed.

  However, when magnetizing by employing the permanent magnet 10 having such a coercive force in the prior art, the coercive force at both ends is high, but sufficient magnetizing magnetic flux is not supplied here. Is insufficient. If the magnetization is inadequate, even if the hard magnetic material 11 is a material as described later and the coercivity of both ends is expected to increase, only the coercivity in the loop passing in the middle of the initial magnetization curve can be obtained. Not realized.

  On the other hand, by performing magnetization using the soft magnetic body 30 as described in the first to fourth embodiments, the permanent magnet 10 including the end portion having a high coercive force can be sufficiently attached. It can be magnetized and can exhibit coercivity in the major loop of the magnetization curve.

  The hard magnetic material 11 is preferably formed by diffusing heavy rare earths (for example, dysprosium) at grain boundaries. More specifically, heavy rare earths are grain boundary diffused at both ends of the hard magnetic body 11. In this grain boundary diffusion method, a predetermined composition is sintered to form a sintered product, and after applying a heavy rare earth workpiece to the sintered product, heat treatment is performed at a temperature lower than the sintering temperature, The hard magnetic body 11 is manufactured. According to this grain boundary diffusion method, the coercivity can be increased by reducing the amount of heavy rare earth added. As the amount of heavy rare earth added is increased, the residual magnetic flux density is lowered. In grain boundary diffusion, such a reduction can be suppressed.

  It should be noted that the techniques of the first to fifth embodiments can be performed in an appropriate combination.

DESCRIPTION OF SYMBOLS 1 Field element 10 Permanent magnet 10a Surface 20 Field element core 22, 23 Air gap part 25 Side surface 26 Air gap 30 Soft magnetic body 40 Connection member 41, 42 Connection part

Claims (18)

A plurality of permanent magnets (10) having a field magnetic flux generating surface (10a) arranged in a ring around the rotation axis (P) and generating a field magnetic flux;
A plurality of storage holes (21) in which the permanent magnets are stored, and a first magnetic pole surface and a second magnetic pole surface that face the plurality of permanent magnets in a radial direction around the rotation axis and have different polarities from each other. Side surfaces (25) alternately formed in the circumferential direction around the rotation axis by the field magnetic flux, and a plurality of air gaps (26), each of the air gaps of the field magnetic flux generating surface Between the first straight lines (A1, A2) passing through both ends in the circumferential direction, a first gap portion that exists in the region (R1) on the side of the permanent magnet in the circumferential direction and in the radial direction (22), and each of the first straight lines is parallel to the radial direction at a boundary closest to itself among boundaries between the first magnetic pole surface and the second magnetic pole surface. A manufacturing method of a field element comprising a core (20) for
A first step (S1) for storing a hard magnetic body (11) that becomes the permanent magnet by magnetization in at least one of the storage holes;
A second step (S2) of inserting a soft magnetic body (30) into the first gap portion corresponding to the hard magnetic body;
After the execution of the first step and the second step, a third step (S3) of forming the permanent magnet by magnetizing the hard magnetic body from the soft magnetic body side;
A field element manufacturing method comprising: a fourth step (S4) for removing the soft magnetic body after the third step. The void (26) has a second void portion (23) provided outside the region (R1) and into which the soft magnetic body (30) is not inserted,
The field element manufacture according to claim 1, wherein the second gap portion extends along the radial direction from an end side in the circumferential direction of the hard magnetic body (11) to the side surface (25). Method.   The field element manufacturing method according to claim 2, wherein the first gap portion (22) and the second gap portion (23) are provided apart from each other in the circumferential direction. In the first step (S1), the hard magnetic body (11) is inserted into all the storage holes (21),
In the second step (S2), the soft magnetic body (30) is inserted into all the first gap portions (22),
In the third step (S3), a magnetic field for magnetization is applied to all the hard magnetic bodies (11) in parallel.
The field element manufacturing method according to any one of claims 1 to 3, wherein in the fourth step (S4), all of the soft magnetic material is removed. In the first step, the soft magnetic body (30) is inserted into at least two of the first gap portions (22),
In the second step (S2), at least two of the soft magnetic bodies are connected to each other by a connecting member (40) on one end side of the rotating shaft (P), and along the rotating shaft (P). The field element manufacturing method according to claim 1, wherein the field element is inserted into the first gap portion.   The field element manufacturing method according to claim 5, wherein the connecting member is non-magnetic. The connecting member (40) has magnetism,
The field magnet according to claim 5, wherein, in the third step (S3), the connecting member (40) and the field element core (20) are separated from each other in an axial direction along the rotation axis (P). Child manufacturing method. The connecting member (40) has first and second connecting portions (41, 42) having magnetism,
The first connecting portion connects the soft magnetic body (30) inserted into the first gap portion (22) corresponding to the permanent magnet (10) that forms the first magnetic pole surface on the side surface. ,
The second connecting portion connects the soft magnetic body inserted into the first gap portion corresponding to the permanent magnet that forms the second magnetic pole surface on the side surface,
The method of manufacturing a field element according to claim 7, wherein in the third step (S3), the first connecting portion and the second connecting portion are magnetically separated from each other.   In the second step (S2), the soft magnetic body (30) connected by the first connecting portion (41) and the soft magnetic body connected by the second connecting portion (42) are 9. The method of manufacturing a field element according to claim 8, wherein the rotating shaft is inserted from opposite sides with respect to the field element core (20).   In the second step (S2), the soft magnetic body (30) connected by the first connecting portion (41) and the soft magnetic body connected by the second connecting portion (42) are The manufacturing method of the field element of Claim 7 inserted from the mutually same side about the said rotating shaft with respect to the core for field elements (20).   11. The method of manufacturing a field element according to claim 10, wherein the first and second connecting portions (41, 42) are integrally molded with a resin before the execution of the second step. Before the execution of the second step (S2), a fifth step (S5) of attaching an end plate (50) to at least one end of the field element core (20) in the axial direction along the rotation axis (P). , S6)
The end plate is formed with a through hole (51) penetrating through the end plate in the axial direction at a position corresponding to the first gap portion (22). Manufacturing method of field element. Before the execution of the third step, further comprising a sixth step of attaching the field element core to a machine element driven by the field element,
The mechanical element has a surface facing the field element core in the axial direction along the rotation axis, and an insertion hole (71) is formed on the surface at a position corresponding to the first gap portion (22). ,
In the sixth step, when attaching the field element core to the machine element, the soft magnetic body is inserted and fixed into the insertion hole through the first gap portion. The manufacturing method of the field element as described in one.   The method of manufacturing a field element according to any one of claims 1 to 13, wherein the soft magnetic body (30) is formed of the same material as the field element core (20).   The field element manufacturing method according to any one of claims 1 to 14, wherein the soft magnetic body (30) includes a plurality of steel plates stacked along the circumferential direction.   The method of manufacturing a field element according to any one of claims 1 to 15, wherein the coercive force at both ends in the circumferential direction of the permanent magnet (10) is higher than that in the center in the circumferential direction.   The field element manufacturing method according to claim 16, wherein the permanent magnet (10) is formed by diffusing heavy rare earths at grain boundaries. A plurality of permanent magnets (10) arranged in a ring around the rotation axis (P) and generating alternately different first and second magnetic poles in a radial direction around the rotation axis;
A plurality of storage holes (21) for storing the permanent magnets and a plurality of air gaps (22) are formed, and each of the air gaps is formed at both ends of each of the permanent magnets in the circumferential direction around the rotation axis. Existing in the region (R1) on the permanent magnet side between the first straight lines (A1, A2) passing through each of the permanent magnets, and each of the first straight lines is between the permanent magnets adjacent in the circumferential direction. An end plate (50) attached to a field element comprising a field element core (20) parallel to a second straight line (B1, B2) passing through a point closest to itself among the points and the rotation axis ) And
A main body (52) that contacts the field element core in the axial direction along the rotation axis;
An end plate for a field element, comprising a through hole (51) formed in the main body portion (52) and penetrating the main body portion in the axial direction at a position corresponding to the gap.

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