JP2016019456A - Motor and fixing method of permanent magnet used for the motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor in which a permanent magnet can be easily fixed in an axial direction and a circumferential direction of a housing, and a fixing method of the permanent magnet.SOLUTION: A motor 1 includes: a housing 10; a bearing mechanism 30; an armature 40 supported through the bearing mechanism 30 to the housing 10 in a freely rotatable manner; and a permanent magnet 50 disposed along an inner peripheral surface of a peripheral surface part 11 of the housing 10. The peripheral surface part 11 includes protrusions 20 that protrudes inside of the housing 10. The protrusions 20 include a first protrusion 21 in contact with at least a part of one edge 51 of the permanent magnet 50, and a second protrusion 22 in contact with at least a part of another edge 52. The first protrusion 21 includes a first bent portion 26 which is bent toward the side of the one edge 51 and brought into contact with a corner of the one edge 51 closer to a cover part 15 in an end closer to the cover part 15. The second protrusion 22 includes a second bent portion 27 which is bent toward the side of the other edge 52 and brought into contact with the other edge 52 at a position excluding a corner closer to a bottom part 14 and a corner closer to the cover part 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor and a fixing method of a permanent magnet used in the motor, and more particularly to a motor in which a magnet is fixed to an inner peripheral surface of a peripheral surface portion constituting a housing and a fixing method of a permanent magnet used in the motor.

  A brushed DC motor or the like includes a permanent magnet inside the housing. Among such motors, there is a motor in which a convex portion protruding toward the inside of the housing is provided on the peripheral surface portion of the housing in order to fix the permanent magnet inside the housing. The permanent magnet is fixed to the peripheral surface portion of the housing by the circumferential edge of the permanent magnet being abutted against the convex portion.

  The motor proposed in Patent Document 1 includes a hollow cylindrical housing. The permanent magnet is fixed to the inner peripheral surface of the housing. The housing has two flat surfaces whose inner peripheral surfaces face each other and two curved surfaces that curve outward. The two flat surfaces are each provided with a protrusion protruding toward the inside of the housing. The permanent magnet has a circular cross-sectional shape. In addition, the permanent magnet includes a plane facing the flat surface and a surface facing the protrusion on the edge of the permanent magnet. The permanent magnet is made of a flexible magnet material. Specifically, the permanent magnet is formed of a mixture mainly composed of magnetic material powder and a binding material.

  The protrusions described above are bitten into the surface of the permanent magnet facing the protrusions by plastic deformation. And the outer peripheral surface of a permanent magnet is pressed against the curved surface of a housing, and the plane of the edge of a permanent magnet is pressed against a flat surface. The permanent magnet is fixed in the housing by such action of the protrusion.

JP-A-5-161285

  However, the motor proposed in Patent Document 1 requires the use of a flexible permanent magnet such as a plastic magnet or a bonded magnet as described above. When such a permanent magnet has a property that is not suitable for press-fitting into the housing, the permanent magnet may be damaged when the permanent magnet is press-fitted into the housing.

  Moreover, the structure with which this motor is provided can prevent a permanent magnet from moving in the circumferential direction. However, with this configuration, it is difficult to prevent the permanent magnet from moving in the axial direction of the housing. Therefore, in this configuration, it is necessary to bond the permanent magnet to the housing with an adhesive. In that case, the permanent magnet may move before the adhesive is cured.

  Generally, a permanent magnet is magnetized after a member configured as a permanent magnet is disposed inside a housing. However, in order to prevent the above-described permanent magnet from moving, it is necessary to provide a step of magnetizing a member configured as a permanent magnet, and to dispose the magnetized member inside the housing. This complicates the motor manufacturing process.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a motor having a structure capable of fixing a permanent magnet in the axial direction and the circumferential direction of a housing by a simple manufacturing process. It is providing the fixing method of the permanent magnet used for this motor.

  A motor according to the present invention for solving the above problems includes a housing having a cylindrical peripheral surface portion, a bottom portion that closes one axial end of the peripheral surface portion, and a lid portion that closes the other axial end of the peripheral surface portion. A bearing mechanism disposed in the housing, an armature rotatably supported with respect to the housing via the bearing mechanism, and a plurality of members disposed along the inner peripheral surface of the peripheral surface portion of the housing An inner peripheral surface of the peripheral surface portion of the housing has a convex portion that extends in the axial direction of the housing and protrudes to the inside of the housing, and the convex portion is a circumferential direction of the housing A first convex portion that contacts at least a part of one end edge of the permanent magnet, and a second convex portion that contacts at least a part of the other end edge of the permanent magnet in the circumferential direction of the housing, The first convex portion is the permanent There is a first bent portion that is bent toward one edge of the permanent magnet at an end of the magnet on the lid side, and the first bent portion is in contact with a corner on the lid of one end of the permanent magnet. The second convex portion has a second bent portion that is bent toward the other end edge side of the permanent magnet at an end portion on the lid portion side of the second convex portion, and the second bent portion is on the bottom side. And any one of the other end sides of the permanent magnet except for the corner on the lid side.

  According to this invention, the first convex portion having the above-described configuration applies a force in the axial direction to fix the permanent magnet, and the second convex portion applies the force in the circumferential direction to fix the permanent magnet. Therefore, the permanent magnet can be fixed in both the circumferential direction and the axial direction. In addition, the permanent magnet is fixed at the end opposite to the end of the permanent magnet facing the bottom side of the permanent magnet, and the second convex is at least at the central position in the axial direction of the permanent magnet. Is fixed, a force is applied to the permanent magnet at different positions in the axial direction. Therefore, the stress of the permanent magnet is dispersed in the axial direction.

  In the motor according to the present invention, the end of the first convex portion on the lid portion side is located farther from the housing bottom than the end portion of the permanent magnet on the lid portion side, and the lid portion of the second convex portion The end on the side is located closer to the bottom of the housing than the end on the lid side of the permanent magnet.

  According to this invention, when the permanent magnet is inserted into the housing, the first convex portion functions as a guide for the permanent magnet. Therefore, the permanent magnet can be easily inserted into the housing.

  In the motor according to the present invention, the first convex portion is longer than the second convex portion.

  According to this invention, when the first bent portion is formed on the first convex portion and the second bent portion is formed on the second convex portion, the permanent magnet can be received in a wide area of the first convex portion. Therefore, it is possible to prevent the permanent magnet from being inclined with respect to the axial direction.

  In the motor according to the present invention, the first convex portion is in contact with the axial length of the permanent magnet.

  According to this invention, since the force applied to the permanent magnet by the second convex portion in the circumferential direction can be received by the entire length of the first convex portion, the stress generated in the permanent magnet can be dispersed.

  In the motor according to the present invention, the motor has two of the permanent magnets, the two permanent magnets surround the armature, and the housing has two first magnets that are in contact with the two permanent magnets, respectively. It has 1 convex part and two said 2nd convex parts, and the said 1st convex part and the said 2nd convex part are alternately arrange | positioned in the circumferential direction.

  According to this invention, since the distance between the permanent magnets can be made uniform in the circumferential direction, the torque generated by the motor can be made uniform.

  In the motor according to the present invention, the motor has two permanent magnets, the two permanent magnets surround the armature, and the housing is in contact with the two first permanent magnets. Having two convex portions and two second convex portions, the two first convex portions being continuously arranged in the circumferential direction, the two second convex portions being continuously arranged in the circumferential direction, The circumferential interval between the two first convex portions is larger than the circumferential interval between the two second convex portions.

  According to this invention, the space | interval of the 1st convex part which opposes is wider than the space | interval of the 2nd convex part which opposes. When a 2nd convex part is deformed among a 1st convex part and a 2nd convex part, the force of the circumferential direction is received and the space | interval of 1st convex parts becomes narrow. By narrowing the interval between the first convex portions, the distance between the permanent magnets can be made uniform in the circumferential direction as a result, and the permanent magnet can be prevented from being displaced in the circumferential direction. . As a result, the torque generated by the motor can be made uniform.

  The fixing method of the permanent magnet which concerns on this invention for solving the said subject has a convex part which protrudes inward from the internal peripheral surface of a cylindrical peripheral surface part, A some along the internal peripheral surface of this peripheral surface part Preparing the housing in which the permanent magnet is arranged, and inserting the tool into the housing, pressing the tool against the convex portion, and bending the convex portion toward the permanent magnet side, the convex portion The housing has a peripheral portion, a bottom portion that closes one axial end of the peripheral surface portion, and a lid portion that closes the other axial end of the peripheral surface portion. The convex portion has a first convex portion located on one end edge side in the circumferential direction of the permanent magnet and a second convex portion located on the other end edge side in the circumferential direction of the permanent magnet, and the tool is The tilt angle formed with the longitudinal direction of the tool is relatively small. And a second inclined surface having a relatively large inclination angle with the longitudinal direction of the tool on one end side in the longitudinal direction, and in the preparing step, the other end in the axial direction of the peripheral surface portion is A housing having a form in which the other end is opened in a stage before being closed by the lid is prepared, and in the bending step, one end side in the longitudinal direction of the tool is inserted from the other end of the housing, At a position relatively close to the other end, the first inclined surface is pressed against an end portion on the other end side in the axial direction of the first convex portion and bent toward the one end edge side, and relatively to the other end. At a distant position, the second inclined surface is pressed against an end portion on the lid portion side in the axial direction of the second convex portion and bent toward the other end edge side.

  According to this invention, since the preparation step and the bending step are provided, the first convex portion is brought into contact with one end edge in the circumferential direction of the permanent magnet, and the second convex portion is brought into contact with the other end in the circumferential direction of the permanent magnet. The edge can be contacted. Therefore, the permanent magnet can be reliably fixed at a predetermined position on the peripheral surface portion of the housing. In particular, according to the present invention, since the above tool is used in the bending step, the bent portions can be simultaneously formed on both the first convex portion and the second convex portion. As a result, the permanent magnet can be efficiently fixed to the peripheral surface portion of the housing.

  According to the present invention, the permanent magnet of the motor can be fixed in the axial direction and the circumferential direction of the housing only through a simple manufacturing process.

It is the perspective view which showed 1st Embodiment of the motor which concerns on this invention with the form which can see an inside. It is a top view which shows the side part of the motor shown in FIG. It is explanatory drawing for demonstrating the positional relationship of a 1st convex part and a 2nd convex part, and the positional relationship of two permanent magnets and each convex part. It is explanatory drawing for demonstrating the positional relationship of the axial direction of a 1st convex part and a permanent magnet, and the axial direction of a 2nd convex part and a permanent magnet. It is explanatory drawing for demonstrating the form which the 1st convex part contacted only the corner | angular of the one end edge of a permanent magnet, and the 2nd convex part contacted the center part of the other end edge of a permanent magnet. It is explanatory drawing for demonstrating the stress which arises in the permanent magnet of the form shown in FIG. It is explanatory drawing for demonstrating the form which the 1st convex part contacted the whole one end edge of the permanent magnet, and the 2nd convex part contacted the center part of the other end edge of a permanent magnet. It is explanatory drawing for demonstrating the stress which arises in the permanent magnet of the form shown in FIG. It is a figure which shows an example of the method of forming a 1st bending part in a 1st convex part, and forming a 2nd bending part in a 2nd convex part. It is the perspective view which showed 2nd Embodiment of the motor which concerns on this invention with the form which can see an inside. It is explanatory drawing for demonstrating the positional relationship of a 1st convex part and a 2nd convex part, and the relationship of the space | interval of two permanent magnets. It is explanatory drawing for demonstrating the permanent magnet with which the motor of a 1st modification is provided, a 1st convex part, and a 2nd convex part. It is explanatory drawing for demonstrating the permanent magnet with which the motor of a 2nd modification is provided, a 1st convex part, and a 2nd convex part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited only to the following description and drawings.

[Basic configuration]
The motor 1 according to the present invention includes a housing 10 as shown in FIGS. 1 and 2, for example. The housing 10 includes a cylindrical peripheral surface portion 11, a bottom portion 14 that closes one end of the peripheral surface portion 11 in the axial direction, and a lid portion 15 that closes the other axial end of the peripheral surface portion 11. The motor 1 includes a bearing mechanism 30 disposed in the housing 10, an armature 40 that is rotatably supported by the housing 10 via the bearing mechanism 30, and an inner peripheral surface of the peripheral surface portion 11 of the housing 10. And a plurality of permanent magnets 50 arranged along the same.

  The peripheral surface portion 11 of the housing 10 includes a convex portion 20 on the inner peripheral surface. The convex portion 20 protrudes inside the housing 10 and extends in the axial direction of the housing 10. The convex part 20 includes a first convex part 21 and a second convex part 22. For example, as shown in FIGS. 5 and 6, the first convex portion 21 contacts at least a part of one end edge 51 of the permanent magnet 50 in the circumferential direction of the housing 10. For example, as illustrated in FIGS. 5 and 6, the second convex portion 22 contacts at least a part of the other end edge 52 of the permanent magnet 50 in the circumferential direction of the housing 10.

  The first convex portion 21 has a first bent portion 26 that is bent toward the one end edge 51 of the permanent magnet 50 at the end portion of the permanent magnet 50 on the lid portion 15 side. The first bent portion 26 is in contact with a corner of the one end edge 51 of the permanent magnet 50 on the lid portion 15 side. The 2nd convex part 22 has the 2nd bending part 27 bent toward the other end edge 52 of the permanent magnet 50 in the edge part by the side of the cover part 15 side. The second bent portion 27 comes into contact with any position of the other end edge 52 of the permanent magnet 50 excluding the corner on the bottom portion 14 side and the corner on the lid portion 15 side.

  According to said structure with which this motor 1 is provided, there exists a specific effect that the permanent magnet 50 of the motor 1 can be fixed to the axial direction of the housing 10, and the circumferential direction only by passing through a simple manufacturing process.

  Hereafter, each structure of this motor 1 is demonstrated with reference to drawings suitably. The motor 1 can be roughly divided into the following first embodiment and second embodiment. As shown in FIGS. 1 to 9, the motor 1 </ b> A of the first embodiment has a plurality of permanent magnets 50, and the plurality of permanent magnets 50 surround the armature 40. The housing 10 has a first convex portion 21 and a second convex portion 22 that are respectively in contact with the plurality of permanent magnets 50, and the first convex portion 21 and the second convex portion 22 are alternately arranged in the circumferential direction. It is a form.

  As shown in FIGS. 10 and 11, the motor 1 </ b> B of the second embodiment has two permanent magnets 50. Two permanent magnets 50 surround the armature 40. The housing 10 has two first convex portions 21 and two second convex portions 22 that are respectively in contact with the plurality of permanent magnets 50. The two first convex portions 21 are continuously arranged in the circumferential direction, the two second convex portions 22 are continuously arranged in the circumferential direction, and the circumferential interval between the two first convex portions 21 is 2 It is a form that is larger than the interval in the circumferential direction of the two second convex portions 22.

[First Embodiment]
As described above, the motor 1A according to the present invention includes the housing 10, the bearing mechanism 30 disposed in the housing 10, the armature 40 rotatably supported on the housing 10 by the bearing mechanism 30, and the peripheral surface portion 11 of the housing 10. A plurality of permanent magnets 50 are provided along the inner peripheral surface of the.

(Housing and bearing mechanism)
As shown in FIGS. 1 and 2, the housing 10 includes a cylindrical peripheral surface portion 11 and a bottom portion 14 that closes one end of the peripheral surface portion 11 in the axial direction. The peripheral surface part 11 and the bottom part 14 are comprised by one member. In addition, the housing 10 includes a lid portion 15 that closes the other end of the circumferential surface portion 11 in the axial direction. The lid portion 15 is configured as a separate body from the peripheral surface portion 11 and the bottom portion 14. The lid 15 closes the other end of the housing 10 in the axial direction after the components constituting the motor 1 </ b> A are accommodated in the housing 10.

  The peripheral surface part 11 is comprised by a pair of flat part 12 and a pair of curved surface part 13 which curves toward the outer side. The flat portions 12 are opposed to each other, and the curved surface portions 13 are also opposed to each other. The flat part 12 includes a convex part 20. The details of the convex portion 20 will be described later. The bottom part 14 and the cover part 15 are each provided with a bearing mechanism 30 at the center thereof. The bearing mechanism 30 supports the armature 40 so as to be rotatable with respect to the housing 10.

(Armature)
The armature 40 includes a rotation shaft 41 located at the center, a core 42 located around the rotation shaft 41, and a coil 43 configured by winding a conductive wire around the core 42. The armature 40 interacts with a field formed by a permanent magnet 50 disposed around the armature 40 to generate torque of the motor 1A. The rotating shaft 41 of the armature 40 is rotatably supported by the housing 10 by the bearing mechanism 30 on both sides of the core 42 in the axial direction of the rotating shaft 41. The rotating shaft 41 protrudes at one end in the axial direction from the bottom portion 14 of the housing 10.

(permanent magnet)
As shown in FIGS. 1 and 3, the permanent magnet 50 is curved in the circumferential direction of the housing 10. Further, the permanent magnet 50 extends linearly in the axial direction of the housing 10. The permanent magnet 50 has an arcuate outer surface 53 and an arcuate inner surface 54. The curvature of the outer surface 53 coincides with the curvature of the inner peripheral surface of the curved surface portion 13 constituting the peripheral surface portion 11 of the housing 10. The inner surface 54 has a curvature that maintains a constant distance from the outer periphery of the core 42 that constitutes the armature 40. Both ends of the permanent magnet 50 in the axial direction are flat. Both end edges 51, 52 in the circumferential direction of the permanent magnet 50 are in contact with the convex portion 20 formed in the housing 10.

(Detail of convex part)
As shown in FIG. 3, the convex portion 20 is formed by causing the flat portion 12 to protrude inside the housing 10. The convex portion 20 includes a first convex portion 21 and a second convex portion 22. The first convex portion 21 and the second convex portion 22 extend in the axial direction of the housing 10. And the 1st convex part 21 and the 2nd convex part 22 are alternately arrange | positioned in the circumferential direction, as shown in FIG. The first convex portion 21 is in contact with one end edge 51 in the circumferential direction of the two permanent magnets 50, and the second convex portion 22 is in contact with the other end edge 52 in the circumferential direction of the two permanent magnets 50. .

(First convex part)
The first convex portion 21 is formed at a position where the one end edge 51 in the circumferential direction of the permanent magnet 50 is disposed, and extends in the axial direction of the housing 10. The end of the first convex portion 21 on the bottom 14 side is located at a position closer to the lid 15 than the end of the permanent magnet 50 on the bottom 14 side, or the same position as the end of the permanent magnet 50 on the bottom 14 side. To do. In the example shown in FIGS. 3 to 6, the end portion of the first convex portion 21 on the bottom portion 14 side is located at a position closer to the lid portion 15 than the end portion of the permanent magnet 50 on the bottom portion 14 side. On the other hand, the end portion of the first convex portion 21 on the lid portion 15 side is located farther from the bottom portion 14 of the housing 10 than the end portion of the permanent magnet 50 on the lid portion 15 side, as shown in FIG. . The distance between the bottom 14 of the housing 10 and the end of the first protrusion 21 on the lid 15 side is L1, and the distance between the bottom 14 of the housing 10 and the end of the first permanent magnet 50 on the lid 15 side is L1. When L2 is L2, the relationship between L1 and L2 is L1> L2.

  Further, as shown in FIGS. 3 to 6, the first convex portion 21 has a configuration in which the axial length is shorter than the axial length of the permanent magnet 50 (hereinafter simply referred to as “short configuration”). As shown in FIGS. 7 and 8, there is a form in which the length in the axial direction is longer than the length in the axial direction of the permanent magnet 50 (hereinafter simply referred to as “long form”). The first convex portion 21 having a short form is a form that contacts only a certain portion of the one end edge 51 of the permanent magnet 50. The long first convex portion 21 contacts the entire length of the one end edge 51 of the permanent magnet 50. In either form, the end portion of the first convex portion 21 on the lid portion 15 side is located farther from the bottom portion 14 of the housing 10 than the end portion of the permanent magnet 50 on the lid portion 15 side.

  The first convex portion 21 is longer in the axial direction than the second convex portion 22 in both the short form and the long form. Thus, when the 1st convex part 21 is longer than the 2nd convex part 22 in an axial direction, when inserting the permanent magnet 50 in the housing 10, the 1st convex part 21 functions as a guide of the permanent magnet 50. . Therefore, the permanent magnet 50 can be easily inserted into the housing 10. Moreover, it can prevent that a permanent magnet inclines with respect to an axial direction.

  Moreover, the 1st convex part 21 has the 1st bending part 26 bent toward the one end edge 51 of the permanent magnet 50 in the edge part by the side of the cover part 15 as shown in FIG. The first bent portion 26 is formed in a portion of the first convex portion 21 that protrudes from the end portion on the lid portion 15 side of the permanent magnet 50. The first bent portion 26 contacts a corner on the lid portion 15 side at one end edge 51 in the circumferential direction of the permanent magnet 50.

  The 1st bending part 26 is formed by plastically deforming the 1st convex part 21, for example. Residual stress remains in the first bent portion 26 of the first convex portion 21 by plastically deforming the first convex portion 21 to form the first bent portion 26. The first convex portion 21 holds the permanent magnet 50 by the first bent portion 26 coming into contact with the permanent magnet 50. For this reason, the 1st convex part 21 fixes the permanent magnet 50 firmly to the position while positioning the permanent magnet 50. FIG. As a result, the first bent portion 26 positions the permanent magnet 50 in the axial direction and prevents the permanent magnet 50 from moving in the axial direction.

(Second convex part)
The second convex portion 22 is provided on the inner peripheral surface of the peripheral surface portion 11 of the housing 10 and extends in the axial direction of the housing 10. The second convex portion 22 is provided at a position where the other end edge 52 in the circumferential direction of the permanent magnet 50 is disposed. The end of the second convex portion 22 on the bottom 14 side is at a position closer to the lid 15 than the end of the permanent magnet 50 on the bottom 14 side, or the same position as the end of the permanent magnet 50 on the bottom 14 side. . On the other hand, the end of the second convex portion 22 on the lid portion 15 side is located in the middle portion of the permanent magnet 50 in the axial direction, as shown in FIG. As shown in FIG. 4, the distance between the bottom portion 14 of the housing 10 and the end portion on the lid portion 15 side of the second convex portion 22 is L3, and the bottom portion 14 of the housing 10 and the lid portion 15 of the first permanent magnet 50. When the distance between the side ends is L4, the relationship between L3 and L4 is L3 <L4.

  The 2nd convex part 22 has the 2nd bending part 27, as shown in FIG. The second bent portion 27 is formed by bending the end portion of the second convex portion 22 on the lid portion 15 side toward the other end edge 52 of the permanent magnet 50. The second bent portion 27 contacts the other end edge 52 in the circumferential direction of the permanent magnet 50. The example shown in FIG. 5 is the form which contacted the axial center part in the other end side of the permanent magnet 50, or the part close | similar to a center part. However, the position where the second bent portion 27 contacts the other end edge 52 in the circumferential direction of the permanent magnet 50 is any part of the region excluding the corner on the bottom portion 14 side and the corner on the lid portion 15 side of the housing 10. Any configuration may be used, and the configuration is not limited to that shown in FIG.

  The second bent portion 27 is formed by, for example, plastic deformation of the second convex portion 22. The second bent portion 27 also has a residual stress like the first bent portion 26. When the second bent portion 27 having residual stress comes into contact with the permanent magnet 50, the second convex portion 22 holds the permanent magnet 50 at the position of the second bent portion 27. For this reason, the second convex portion 22 simply positions the permanent magnet 50 and firmly fixes the positioned permanent magnet 50 to the position. As a result, the second bent portion 27 positions the permanent magnet 50 in the circumferential direction and prevents the permanent magnet 50 from moving in the circumferential direction.

(Relationship between the position where each convex part contacts the permanent magnet and the stress)
The first convex portion 21 in a short form partially contacts one end edge 51 of the permanent magnet 50, and the second convex portion 22 is located at the center of the other end edge 52 of the permanent magnet 50 at the position of the second bent portion 27. The case of contact will be described with reference to FIGS.

  When the 1st convex part 21 and the 2nd convex part 22 contact the permanent magnet 50 in the same position of an axial direction, as shown in FIG. 6, the stress which arises in the permanent magnet 50 is the 1st convex part 21 and 2nd. It will concentrate on the fixed range centering on the position which the convex part 22 contacts. 6 schematically shows the distribution of stress generated in the permanent magnet 50 when the first convex portion 21 and the second convex portion 22 contact the permanent magnet 50 at the same position in the axial direction. It is shown.

  On the other hand, in the motor of the present embodiment, the position where the first convex portion 21 contacts the permanent magnet 50 and the position where the second convex portion 22 contacts the permanent magnet 50 are as shown in FIGS. It exists in a different direction. The form which the 1st convex part 21 and the 2nd convex part 22 contact the permanent magnet 50 in the position where an axial direction differs is the 1st convex part 21 and the 2nd convex part 22 in the same position of an axial direction. Compared with the form which contacts, the stress produced in the permanent magnet 50 can be distributed in the axial direction. Therefore, the form which the 1st convex part 21 and the 2nd convex part 22 contact the permanent magnet 50 in the position where an axial direction differs is a relatively strong force in the position of the 1st bending part 26 and the 2nd bending part 27. The permanent magnet 50 can be held.

  Next, the long first convex portion 21 contacts the entire length of one end edge 51 of the permanent magnet 50, and the second convex portion 22 is located at the center of the other end edge 52 of the permanent magnet 50 at the position of the second bent portion 27. The case of contacting the part will be described with reference to FIGS.

  In this embodiment, as shown in FIGS. 7 and 8, the first convex portion 21 contacts over the entire length of the one end edge 51 of the permanent magnet 50. On the other hand, the second convex portion 22 is in contact with the central portion of the other end edge 52 of the permanent magnet 50 at the position of the second bent portion 27.

  The form in which the entire axial direction of the first convex portion 21 is in contact with the one end edge 51 of the permanent magnet 50 and the second convex portion 22 is in contact with the permanent magnet 50 at the position of the second bent portion 27 is a broken line in FIG. As can be seen, the stress generated in the permanent magnet 50 can be dispersed in the axial direction. Therefore, the form which the 1st convex part 21 contacts the permanent magnet 50 in the whole axial direction hold | maintains the permanent magnet 50 with a relatively strong force in the position of the 1st bending part 26 and the 2nd bending part 27. it can.

  As shown in FIG. 3, when the first protrusions 21 and the second protrusions 22 are alternately arranged in the circumferential direction and are brought into contact with the permanent magnet 50 as described above, the two second protrusions 22. The second bent portion 27 contacts the other end edge 52 of each of the two permanent magnets 50 and applies a force to the first convex portion 21 side. Therefore, the distance between the two permanent magnets 50 is maintained uniformly in the circumferential direction. As a result, the torque generated by the motor 1A becomes uniform.

  As mentioned above, while the 1st convex part 21 contacts the end edge 51 in the circumferential direction of the permanent magnet 50 with the form which gives force to the permanent magnet 50, the 2nd convex part 22 has the form which gives force to the permanent magnet 50. The motor 1A that contacts the other end edge 52 in the circumferential direction has been described as an example. However, in the motor 1A, the first convex portion 21 does not apply a force to the permanent magnet 50, the first convex portion 21 is simply brought into contact with the one end edge 51 in the circumferential direction of the permanent magnet 50, and the second convex portion 22 is permanent. It can also be configured by simply applying the second convex portion 22 to the other end edge 52 in the circumferential direction of the permanent magnet 50 without applying a force to the magnet 50.

  Further, the case where two permanent magnets 50 are arranged on the inner peripheral surface of the peripheral surface portion 11 of the housing 10 has been described as an example. However, the motor 1 </ b> A can also be configured by arranging three or more permanent magnets 50 on the inner peripheral surface of the peripheral surface portion 11 of the housing 10. In that case, three first protrusions 21 and two protrusions 22 are formed on the peripheral surface portion 11 of the housing 10. And the 1st convex part 21 contacts the edge 51 of the circumferential direction of each permanent magnet 50, respectively. On the other hand, the 2nd convex part 22 contacts the other end edge 52 of the circumferential direction of each permanent magnet 50, respectively.

[Fixing method of permanent magnet]
Next, an example of a method for fixing the permanent magnet 50 to a predetermined position of the peripheral surface portion 11 of the housing 10 will be described with reference to FIG. The permanent magnet 50 is fixed by forming the first bent portion 26 on the first convex portion 21 and forming the second bent portion 27 on the second convex portion 22.

  The permanent magnet is fixed by preparing a housing 10 having a plurality of permanent magnets 50 arranged on the inner peripheral surface of the peripheral surface portion 11, inserting the tool 100 into the housing 10, and inserting the tool 100 into the convex portion 20. And a bending step of bringing the convex portion 20 into contact with the permanent magnet 50 by bending the convex portion 20 toward the permanent magnet 50 side.

  The housing 10 is a component used in the motor 1 described so far, and closes the peripheral surface portion 11, the bottom portion 14 that closes one end of the peripheral surface portion 11 in the axial direction, and the other end in the axial direction of the peripheral surface portion 11. A lid 15 is provided. However, in the preparation step, as shown in FIG. 9, the housing 10 having the other end opened is prepared before the other end in the axial direction of the peripheral surface portion 11 is closed by the lid portion 15. Moreover, the convex part 20 has the 1st convex part 21 located in the circumferential direction one end edge 51 side in the permanent magnet 50, and the 2nd convex part 22 located in the circumferential direction other end edge 52 side in the permanent magnet 50. Have. The tool 100 includes a first inclined surface 103 having a relatively small inclination angle θ1 formed with the longitudinal direction of the tool 100, and a second inclined surface having a relatively large inclination angle θ2 formed with the longitudinal direction of the tool 100. 104 is provided on one end side in the longitudinal direction.

  In the bending process, one end side in the longitudinal direction of the tool 100 is inserted from the other end of the housing 100. In the following description, the end portion side of the housing 10 that is closed by the lid portion 15 will be described as the “lid portion 15 side”. When the tool 100 is inserted into the housing 10, the first inclined surface 103 is relatively close to the lid 15 side of the housing 10, and the end of the first convex portion 21 on the lid 15 side in the axial direction. Pressed against. The pressed end of the lid 15 is bent toward the one end edge 51 of the permanent magnet 50. Further, when the tool 100 is inserted into the housing 10, the second inclined surface 104 is located at a position relatively far from the lid portion 15 side of the housing 10, and is on the lid portion 15 side in the axial direction of the second convex portion 22. Pressed against the edge. The pressed end of the lid 15 is bent toward the other end 52 of the permanent magnet 50.

  The permanent magnet 50 is fixed to a predetermined position on the peripheral surface portion 11 of the housing 10 through the above preparation process and bending process. The method for fixing the permanent magnet 50 will be specifically described below.

  The 1st bending part 26 and the 2nd bending part 27 are formed using the tool 100 shown in FIG. 9, for example. The tool 100 is a rod-shaped member having a square cross section. One end side of the tool 100 in the axial direction has inclined surfaces 103 and 104 on opposite side surfaces 101 and 102, respectively. The first inclined surface 103 has a relatively small inclination angle θ <b> 1 formed with the longitudinal direction of the tool 100 and is connected to the side surface 101 at a position relatively far from one end of the tool 100. The second inclined surface 104 has a relatively large inclination angle θ <b> 2 with respect to the longitudinal direction of the tool 100, and is connected to the side surface 102 at a position relatively close to one end of the tool 100.

  The tool 100 is used by being inserted into the housing 10 in which the permanent magnet 50 is disposed. The tool 100 is inserted into the housing 10 with one end side where the inclined surfaces 103 and 104 are formed from the lid portion 15 side. When the tool 100 is inserted, the first inclined surface 103 having a small inclination angle θ <b> 1 is directed toward the first convex portion 21, and the second inclined surface 104 having a large inclination angle θ <b> 2 is directed to the second convex portion 22.

  When the tool 100 is inserted into the housing 10, the base portion of the first inclined surface 103 near the side surface 101 pushes the end of the first convex portion 21 on the lid portion 15 side outward. The first bent portion 26 is formed by pressing the end portion on the lid portion 15 side of the first convex portion 21 against the first inclined surface 103. Further, when the tool 100 is inserted into the housing 10, the base portion of the second inclined surface 104 near the side surface 102 is the end of the second convex portion 22 on the lid portion 15 side, and the other end of the permanent magnet 50. Push toward edge 52. The second bent portion 27 is formed by pressing the end portion of the second convex portion 22 on the lid portion 15 side against the second inclined surface 104.

  In other words, one end side in the longitudinal direction of the tool 100 is inserted from the lid 15 side of the housing 10. When the first inclined surface 103 is pressed against the end portion on the lid portion 15 side in the axial direction of the first convex portion 21 at a position relatively close to the lid portion 15 side of the housing 10, the first convex portion 21 is pressed. The end portion on the lid portion 15 side is bent toward the one end edge 51 side in the circumferential direction of the permanent magnet 50. Further, the second inclined surface 104 is pressed against the end portion on the lid portion 15 side in the axial direction of the second convex portion 22 at a position relatively far from the lid portion 15 side of the housing 10, whereby the second convex surface is formed. The end portion of the portion 22 on the lid portion 15 side is bent toward the other end edge 52 side in the circumferential direction of the permanent magnet 50. In that case, the bending of the end portion of the first convex portion 21 on the lid portion 15 side and the bending of the end portion of the second convex portion 22 on the lid portion 15 side are one for inserting the tool 100 into the housing 10. Performed simultaneously in the process.

[Second Embodiment]
Next, a motor 1B of the second embodiment will be described with reference to FIGS. Note that the motor 1B of the second embodiment differs from the motor 1A of the first embodiment in the circumferential arrangement of the first convex portion 21 and the second convex portion 22. However, the configuration of the motor 1B of the second embodiment and the configuration of the motor 1A of the first embodiment are the same except for the circumferential arrangement of the first convex portion 21 and the second convex portion 22. Therefore, in the motor 1B of the second embodiment, the same reference numerals as those of the motor 1A of the first embodiment are attached to the drawings for the same configurations as those of the motor 1A of the first embodiment, and the description thereof is omitted. Only the arrangement of the first protrusion 21 and the second protrusion 22 in the circumferential direction and the operation thereof will be described.

  As shown in FIG. 10, the motor 1 </ b> B of the second embodiment includes a housing 10, a bearing mechanism 30 disposed in the housing 10, an armature 40 that is rotatably supported with respect to the housing 10, and a peripheral surface portion of the housing 10. A plurality of permanent magnets 50 are provided along the inner peripheral surface of the. In the example shown in FIGS. 10 and 11, two permanent magnets 50 are provided in the motor 1B. Two permanent magnets 50 surround the armature 40.

  The housing 10 includes a cylindrical peripheral surface portion 11 and a bottom portion 14 that closes one end of the peripheral surface portion 11 in the axial direction. The housing 10 also has a lid portion 15 that closes the other end in the axial direction. The peripheral surface part 11 which comprises the housing 10 is comprised by a pair of flat part 12, and a pair of curved surface part 13 which curves toward the outer side. The flat portions 12 are opposed to each other. The flat portion 12 has two first convex portions 21 and two second convex portions 22 that are respectively in contact with the two permanent magnets 50.

  The two first convex portions 21 are continuously arranged in the circumferential direction. The two second convex portions 22 are continuously arranged in the circumferential direction. Specifically, the two first convex portions 21 are provided in parallel to the one flat portion 12 constituting the peripheral surface portion 11. Further, the two second convex portions 22 are provided in parallel with the other flat portion 12 constituting the peripheral surface portion 11. An interval X1 in the circumferential direction between the two first convex portions 21 is larger than an interval X2 in the circumferential direction between the two second convex portions 22.

  In the motor 1B, as described above, the interval X1 between the first convex portions 21 is larger than the interval X2 between the second convex portions 22. By deforming the second convex portion 22, the interval between the first convex portions 21 receiving the force acting in the circumferential direction is narrowed. As a result of the interval between the first convex portions 21 becoming narrow, the distance between the one end edges 51 and the distance between the other end edges 52 of the two permanent magnets 50 become uniform in the circumferential direction. As a result, the torque generated by the motor 1B becomes uniform.

[Modification]
In the motor 1 described above, the one end edge 51 and the other end edge 52 in the circumferential direction of the permanent magnet 50 are linear. However, the motor can also be configured using a permanent magnet having a step or the like at one end edge or the other end edge in the circumferential direction. The configuration of the motor 1C of the first modification other than the permanent magnet 60 and the convex portion 120 is the same as the configuration of the motor 1 of the first embodiment described above. Moreover, also about the motor 1D of the modified example 2, the configuration other than the permanent magnet 70 and the convex portion 220 is the same as the configuration of the motor 1 of the first embodiment described above. Therefore, the motor 1C of the first modification and the motor 1D of the second modification will be described with only the permanent magnets 60 and 70 and the convex portions 120 and 220 shown in the drawings.

(First modification)
As shown in FIG. 12, the motor 1 </ b> C of the first modification includes a permanent magnet 60 and a convex portion 120 projecting inside the housing inside a housing (not shown). 12, the upper side of FIG. 12 is the bottom side of the housing, and the lower side of FIG. 12 is the lid side of the housing. One end edge 61 in the circumferential direction of the permanent magnet 60 has a recess 65 in which an intermediate portion in the axial direction is recessed toward the other end edge 62 side. The concave portion 65 includes side portions 66 and 67 that extend in the circumferential direction and face each other, and a bottom portion 68 that extends in the axial direction and connects the side portions 66 and 67 to each other. The convex part 120 is composed of a first convex part 121 and a second convex part 122.

  The first convex portion 121 is provided on the one end edge 61 side in the circumferential direction of the permanent magnet 60. The first convex portion 121 extends in the axial direction between the end portion on the bottom side and the side portion 66 of the concave portion 65. The first convex portion 121 has a first bent portion 126 at the end portion on the concave portion 65 side. The first bent portion 126 is configured by bending the end portion on the concave portion 65 side of the first convex portion 121 toward the side portion 66 of the concave portion 65. The first bent portion 126 is in contact with a corner formed by the one end edge 61 of the permanent magnet 60 and the side portion 66 of the recess 65.

  The first convex portion 121 brings the circumferential position of the permanent magnet 60 into contact with the corner formed by the one end edge 61 of the permanent magnet 60 and the side portion 66 of the concave portion 65. At the same time, the position of the permanent magnet 60 in the axial direction is determined.

  The second convex portion 122 extends in the axial direction on the other end edge 62 side in the circumferential direction of the permanent magnet 60. The 2nd convex part 122 has the 2nd bending part 127 which contacts the other end edge 62 of the circumferential direction of the permanent magnet 60 in the edge part by the side of a cover part. The second bent portion 127 is formed by bending the end portion on the lid portion side of the second convex portion 122 toward the other end edge 62 of the permanent magnet 60. And the 2nd convex part 122 determines the position of the circumferential direction of the permanent magnet 60 by making the 2nd bending part 127 contact the other end edge 62 of the permanent magnet 60. FIG.

(Second modification)
As shown in FIG. 13, the motor 1 </ b> D of the second modification includes a permanent magnet 70 and a convex portion 220 that protrudes inside a housing (not shown). The upper side of FIG. 13 is the bottom side of the housing, and the lower side of FIG. 13 is the lid side of the housing.

  The one end edge 71 of the permanent magnet 70 has a first end edge 76 constituting the one end edge 71 in the bottom side area and a second end edge 77 constituting the one end edge 71 in the lid side area. . The one end edge 71 of the permanent magnet 70 has a third end edge 78 that extends in the circumferential direction at an intermediate portion in the axial direction and connects the first end edge 76 and the second end edge 77. On the other hand, the other end edge 72 of the permanent magnet 70 extends linearly in the axial direction.

  The convex part 220 includes a first convex part 221 and a second convex part 222.

  The first convex portion 221 is provided on the one end edge 71 side in the circumferential direction of the permanent magnet 70. The first convex portion 221 extends in the axial direction between the end portion on the bottom side and the third end edge 78. The first convex portion 221 has a first bent portion 226 at the end portion on the third end edge 78 side. The first bent portion 226 is configured by bending an end portion of the first convex portion 221 on the third end edge 78 side toward the third end edge 78. The first bent portion 226 is in contact with the corner formed by the first end edge 76 and the third end edge 78 of the permanent magnet 70. The first convex portion 221 determines the circumferential position of the permanent magnet 70 and the axial position of the permanent magnet 70.

  The second convex portion 222 extends in the axial direction on the other end edge 72 side in the circumferential direction of the permanent magnet 70. This 2nd convex part 222 has the 2nd bending part 227 which contacts the other end edge 72 of the circumferential direction of the permanent magnet 70 in the edge part by the side of a cover part. The second convex portion 222 determines the circumferential position of the permanent magnet 70 by bringing the second bent portion 227 into contact with the other end edge 72 of the permanent magnet 70.

1, 1A, 1B, 1C, 1D Motor 10 Housing 11 Peripheral surface portion 12 Flat portion 13 Curved surface portion 14 Bottom portion 15 Lid portion 20, 120, 220 Convex portion 21, 121, 221 First convex portion 22, 122, 222 Second convex portion Part 26, 126, 226 First bent part 27, 127, 227 Second bent part 30 Bearing mechanism 40 Armature 41 Rotating shaft 42 Core 43 Coil 50, 60, 70 Permanent magnet 51, 61, 71 One end edge 52, 62, 72 Other end edge 53 Outer surface 54 Inner surface 65 Recessed portion 66, 67 Side side portion 68 Bottom side portion 76 First edge 77 Second edge 78 Third edge 100 Tool 101, 102 Side surface 103 First inclined surface 104 Second inclined surface Inclined surface

Claims (7)

A housing having a cylindrical peripheral surface portion, a bottom portion that closes one end in the axial direction of the peripheral surface portion, and a lid portion that closes the other axial end of the peripheral surface portion;
A bearing mechanism disposed in the housing;
An armature rotatably supported with respect to the housing via the bearing mechanism;
A plurality of permanent magnets arranged along the inner peripheral surface of the peripheral surface portion of the housing,
The inner peripheral surface of the peripheral surface portion of the housing has a convex portion that extends in the axial direction of the housing and projects inside the housing,
The convex portion includes a first convex portion that contacts at least part of one end edge of the permanent magnet in the circumferential direction of the housing, and at least part of the other end edge of the permanent magnet in the circumferential direction of the housing. A second convex part that comes into contact with,
The first convex portion has a first bent portion that is bent toward one end edge side of the permanent magnet at an end portion on the lid portion side of the permanent magnet,
The first bent portion is in contact with a corner on the lid portion side of one end edge of the permanent magnet,
The second convex portion has a second bent portion that is bent toward the other end edge side of the permanent magnet at an end portion of the second convex portion on the lid portion side,
The second bent portion is in contact with a position on the other end side of the permanent magnet excluding a corner on the bottom side and a corner on the lid side. The end on the lid side of the first convex part is located at a position farther from the bottom of the housing than the end on the lid side of the permanent magnet,
2. The motor according to claim 1, wherein an end portion on the lid portion side of the second convex portion is positioned closer to the housing bottom portion than an end portion on the lid portion side of the permanent magnet.   The motor according to claim 1, wherein the first protrusion is longer than the second protrusion.   4. The motor according to claim 1, wherein the first convex portion is in contact with a total length of the permanent magnet in the axial direction. The motor has two of the permanent magnets, the two permanent magnets surround the armature, and the housing has two first convex portions and two of the two permanent magnets that are in contact with the two permanent magnets, respectively. A second convex portion,
The motor according to any one of claims 1 to 4, wherein the first protrusions and the second protrusions are alternately arranged in a circumferential direction. The motor has two of the permanent magnets, and the two permanent magnets surround the armature,
The housing has two first convex portions and two second convex portions that are in contact with the two permanent magnets, respectively.
The two first convex portions are continuously arranged in the circumferential direction, the two second convex portions are continuously arranged in the circumferential direction,
The motor according to any one of claims 1 to 4, wherein a circumferential interval between the two first convex portions is larger than a circumferential interval between the two second convex portions. A preparatory step of preparing a housing having a convex portion protruding inward from the inner peripheral surface of the cylindrical peripheral surface portion, and a plurality of permanent magnets arranged along the inner peripheral surface of the peripheral surface portion;
A bending step of inserting a tool into the housing, pressing the tool against the convex portion, and bending the convex portion toward the permanent magnet to bring the convex portion into contact with the permanent magnet. ,
The housing includes the peripheral surface portion, a bottom portion that closes one end in the axial direction of the peripheral surface portion, and a lid portion that closes the other axial end of the peripheral surface portion,
The convex portion has a first convex portion located on one end edge side in the circumferential direction of the permanent magnet, and a second convex portion located on the other end edge side in the circumferential direction of the permanent magnet,
The tool includes a first inclined surface having a relatively small inclination angle with the longitudinal direction of the tool and a second inclined surface with a relatively large inclination angle formed with the longitudinal direction of the tool. Prepare for one end,
In the preparation step, a housing in a form in which the other end is opened in a stage before the other end in the axial direction of the peripheral surface portion is closed by the lid portion is prepared,
In the bending step, one end side in the longitudinal direction of the tool is inserted from the other end of the housing, and the first inclined surface is in the axial direction of the first convex portion at a position relatively close to the other end. Is pressed against the end portion on the other end side and bent toward the one end edge side, and at a position relatively far from the other end, the second inclined surface is disposed on the lid portion side in the axial direction of the second convex portion. A method of fixing a permanent magnet, wherein the permanent magnet is bent to the other end edge side by being pressed against an end portion.

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