JP2019068588A - Rotor - Google Patents

Abstract

To provide a rotor capable of improving motor characteristics by preventing a magnetic saturation.SOLUTION: A rotor 1 can rotate an outer peripheral side of a stator in a circumferential direction about a center axis extending in a vertical direction, and comprises: a magnet 13 in which a plurality of magnetic poles are alternately positioned in the circumferential direction; and a rotor yoke 12 disposed on the outer peripheral side of the magnet. The rotor yoke comprises at least: a wide part 121 where the width in a radial direction is wide; and a narrow part 122 where the width in the radial direction is narrower than the wide part. In each of magnetic pole parts 13A to 13C constituting a magnetic pole, a central part in the circumferential direction of the magnetic part is positioned in the narrow part, and an end part of the circumferential direction of the magnetic pole part is positioned in the wide part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a rotor used for a motor.

  As a conventional motor, there is a so-called outer rotor type motor in which a rotor is located on the outer peripheral side of a stator. An example of such a conventional motor is disclosed in Patent Document 1.

  The electric motor of Patent Document 1 is an outer rotor type in which a rotor is positioned outward around the stator. The rotor has a frame. The frame is formed by pressing a magnetic material into a covered cylindrical container shape.

  On the inner circumferential surface of the circumferential side of the frame, a plurality of magnets are arranged all around the circumference, with the magnetic properties of N and S being alternately different. A synthetic resin mold is applied from adjacent portions of the magnet to between the magnet and the frame.

Japanese Patent Application Laid-Open No. 2003-299282

  In Patent Document 1 described above, the magnetic flux flowing from the outer peripheral surface of the magnet increases as it goes to the magnet adjacent to the magnet, so the amount of magnetic flux increases at a location between adjacent magnets. Here, since the radial width of the frame is constant, the magnetic flux density is increased at the portion of the frame between the adjacent magnets.

  As a characteristic of the magnetic substance, magnetic saturation occurs when the magnetic flux density becomes a certain value or more. As described above, when the magnetic flux density is increased, magnetic saturation occurs and the magnetic flux does not flow more than a predetermined amount. This is disadvantageous in terms of the characteristics of the motor such as efficiency and torque.

  In view of the above situation, the present invention aims to provide a rotor capable of preventing magnetic saturation and improving motor characteristics.

  An exemplary rotor according to the present invention is a rotor capable of circumferentially rotating an outer peripheral side of a stator around a vertically extending central axis, wherein the magnet has a plurality of magnetic poles alternately positioned in the circumferential direction; A rotor yoke disposed on the outer peripheral side of the magnetic pole, and the rotor yoke at least includes a wide portion wide in the radial direction and a narrow portion narrow in the radial direction than the wide portion; In the magnetic pole portion constituting the magnetic pole portion, the circumferential central portion of the magnetic pole portion is located at the narrow width portion, and the circumferential end portion of the magnetic pole portion is located at the wide width portion.

  The exemplary rotor of the present invention can prevent magnetic saturation to improve motor characteristics.

FIG. 1 is a perspective view from above showing the configuration of the rotor and the stator according to the first embodiment. FIG. 2 is a perspective view from below showing the configuration of the rotor and the stator according to the first embodiment. FIG. 3 is a plan sectional view of the rotor and the stator according to the first embodiment as viewed in the axial direction. FIG. 4 is a perspective view from above showing the configuration of the rotor and the stator according to the second embodiment. FIG. 5 is a perspective view from below showing the configuration of the rotor and the stator according to the second embodiment. FIG. 6 is a perspective view from above showing the configuration of the rotor and the stator according to the third embodiment. FIG. 7 is a perspective view from below showing the configuration of the rotor and the stator according to the third embodiment. FIG. 8 is a plan sectional view of the rotor and the stator according to the third embodiment as viewed in the axial direction. FIG. 9 is a perspective view from above showing the configuration of the rotor and the stator according to the fourth embodiment. FIG. 10 is a perspective view from below showing the configuration of the rotor and the stator according to the fourth embodiment. FIG. 11 is a plan sectional view of the rotor and the stator according to the fourth embodiment as viewed in the axial direction. FIG. 12 is a perspective view from above showing the configuration of the rotor and the stator according to the fifth embodiment. FIG. 13 is a perspective view from below showing the configuration of the rotor and the stator according to the fifth embodiment. FIG. 14 is a schematic partial vertical cross-sectional view showing a configuration for fixing the frame to the rotor core by caulking. FIG. 15 is an axial cross-sectional plan view showing an example of a rotor in the case of using a single magnet.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In this specification, a direction parallel to the central axis extending in the vertical direction is "axial direction", a direction perpendicular to the central axis is "radial direction", and a direction along an arc centered on the central axis is "circumferential direction" It is called respectively. However, the definition of these directions is not intended to limit the use direction of the motor according to the present embodiment.

  In addition, all of the embodiments related to the rotor and the stator described below are configurations included in a so-called outer rotor type motor.

<1. First embodiment>
First, a rotor and a stator according to a first embodiment of the present invention will be described. FIG. 1 is a perspective view from above showing the configuration of the rotor 1 and the stator 2 according to the first embodiment. FIG. 2 is a perspective view from below showing the configuration of the rotor 1 and the stator 2. FIG. 3 is a plan sectional view in which the rotor 1 and the stator 2 are viewed in the axial direction.

  The rotor 1 can rotate around the central axis C in the circumferential direction on the outer peripheral side of the stator 2. Accordingly, the motor including the rotor 1 and the stator 2 is of the outer rotor type.

  The stator 2 has a stator core 21, an insulator 22, and a coil 23.

  The stator core 21 is configured by laminating magnetic steel plates in the axial direction. The stator core 21 has a core back 211 and teeth 212. The core back 211 has an axially extending cylindrical shape. A plurality of teeth 212 protrude radially outward from the outer peripheral surface of the core back 211. The teeth 212 have a radially extending base portion 212A and an enlarged portion 212B extending from the radially outer end of the base portion 212A to both circumferential sides. That is, the teeth 212 have a substantially T shape in a plan cross section viewed from the axial direction.

  The insulator 22 is formed of an insulating material, and includes an upper insulator and a lower insulator. The upper insulator and the lower insulator sandwich the stator core 21 from above and below. The insulator 22 covers the radially inner side surface of the enlarged portion 212B while covering the upper and lower surfaces and both side surfaces in the circumferential direction of the base 212A.

  The coil 23 is configured by winding a conducting wire via the insulator 22 around the outer periphery of each base 212A. That is, the coils 23 are arranged in the same number as the number of teeth 212.

  The rotor 1 has a top plate frame 11, a rotor core 12, and a plurality of magnets 13.

  The top plate frame 11 has a disk shape and is formed of carbon steel or the like. The rotor core 12 is disposed below the top frame 11. The rotor core 12 has a substantially cylindrical shape extending in the axial direction with the radially inner side opened. The rotor core 12 is formed by laminating magnetic steel plates in the axial direction, and corresponds to a rotor yoke.

  The plurality of magnets 13 are arranged circumferentially along the inner circumferential surface of the rotor core 12. The outer peripheral surface of the magnet 13 and the inner peripheral surface of the magnet 13 both have an arc shape centering on the central axis C. The inner circumferential surface of the rotor core 12 is circular around the central axis C. The entire circumferential direction of the outer peripheral surface of the magnet 13 contacts the inner peripheral surface of the rotor core 12. The magnet 13 is fixed to the inner peripheral surface of the rotor core 12 by an adhesive or the like.

  A hole 111 is formed at the radial center of the top frame 1. A shaft (not shown) axially extending in the hole 111 is fixed directly or indirectly via another component. The shaft passes through the inside of an axially extending through hole 21A provided at the radial center of the stator core 21. The shaft is rotatably held circumferentially by a bearing (not shown). The current supplied to the coil 23 causes the rotor 1 to rotate on the outer peripheral side of the stator 2 by the interaction between the magnetic field of the coil 23 and the magnetic field of the magnet 13. Thus, the motor is driven.

  A gap SP is provided between the magnets 13 adjacent in the circumferential direction. The radially outer side of each magnet 13 is magnetized to either the N pole or the S pole, and the radially inner side is magnetized to a magnetic pole opposite to the radially outer side. The magnetic poles shown in FIG. 3 indicate magnetic poles magnetized radially outward of the respective magnets 13. Thus, the radially outer poles of the magnet 13 are alternately arranged in the circumferential direction. Each magnet 13 corresponds to a magnetic pole portion constituting a magnetic pole.

  In FIG. 3, three magnets 13 adjacent in the circumferential direction are representatively shown as magnetic pole portions 13A, 13B, 13C. The magnetic pole portion 13B is adjacent to one circumferential side of the magnetic pole portion 13A, and the magnetic pole portion 13C is adjacent to the other circumferential side of the magnetic pole portion 13A.

  The radial width of the rotor core 12 gradually widens from the position of the circumferentially central portion of the magnetic pole portion 13A toward the circumferential one side end and the circumferential other side end of the magnetic pole portion 13A. The same applies to the relationship between the magnetic pole portions 13B and 13C and the rotor core 12. As a result, the rotor core 12 is formed with a wide portion 121 having a wide radial direction width and a narrow portion 122 having a narrow radial direction width. The wide portions 121 are disposed at positions between adjacent magnetic pole portions among the magnetic pole portions 13A to 13C. The narrow portion 122 is disposed at the center position of each of the magnetic pole portions 13A to 13C in the circumferential direction. The same applies to the relationship between the magnetic pole parts other than the magnetic pole parts 13A to 13C and the rotor core 12, so the wide part 121 and the narrow part 122 are formed side by side in the circumferential direction.

  The magnetic flux M is shown in FIG. In the rotor core 12, the magnetic flux M flowing from one to the other of the adjacent magnetic pole portions increases at the portion between the adjacent magnetic pole portions, but since the wide portion 121 is disposed at this portion, the magnetic flux density is Reduced. Therefore, the occurrence of magnetic saturation is prevented, and the magnetic flux from the magnet can be used more effectively. Thereby, the characteristics of the motor including the rotor 1 can be improved.

That is, the rotor according to the present embodiment is a rotor (1) capable of circumferentially rotating the outer peripheral side of the stator (2) about a central axis (C) extending in the vertical direction, and a plurality of magnetic poles are circumferential Magnets (13) alternately located on the outer surface of the rotor, and a rotor yoke (12) disposed on the outer peripheral side of the magnets;
Equipped with The rotor yoke (12) includes at least a wide portion (121) having a wide radial width and a narrow portion (122) having a smaller radial width than the wide portion. In the magnetic pole parts (13A to 13C etc.) constituting the magnetic pole, the circumferential center part of the magnetic pole part is located at the narrow width part, and the circumferential end part of the magnetic pole part is located at the wide width part.

  According to such a configuration, the magnetic flux density is reduced and the occurrence of magnetic saturation is prevented by widening the radial width of the rotor yoke at circumferential positions between the magnetic pole portions where the amount of magnetic flux by the magnet becomes large. . Therefore, the magnetic flux from the magnet can be used more effectively, and the motor characteristics can be improved.

  The rotor yoke is a rotor core (12) in which a plurality of steel plates are stacked. The rotor core is formed by axially laminating steel plates formed by punching using a press, so that the shape including the wide portion and the narrow portion can be easily formed.

  Further, the outer circumferential surface of the wide portion (121) protrudes radially outward from the outer circumferential surface of the narrow portion (122). As a result, both the outer peripheral surface of the magnet and the inner peripheral surface of the rotor yoke can be simplified in shape, and the accuracy of contact between the magnet and the rotor yoke can be easily improved. Further, since the outer peripheral surface of the rotor yoke protrudes, it is possible to reduce the magnetic flux density at the location where the magnetic flux is concentrated.

  The top frame 11 is fixed to the rotor core 12 by a plurality of rivets R. The rivet R penetrates the top plate frame 11 and the rotor core 12 in the axial direction. The rivets R are disposed at circumferentially central positions of the respective magnets 13. That is, the rotor (1) further includes a fixing member (R) inserted in the rotor yoke (12) in the axial direction, and the fixing member is disposed at the circumferential center position of the magnetic pole portions (13A to 13C etc.) Be done.

  Thereby, since the magnetic flux is small at the circumferentially central position of the magnetic pole portion, the influence of the fixing member on the flow of the magnetic flux can be suppressed.

<2. Second embodiment>
Next, a rotor and a stator according to a second embodiment of the present invention will be described. FIG. 4 is a perspective view from above showing the configuration of the rotor 3 and the stator 2 according to the second embodiment. FIG. 5 is a perspective view from below showing the configuration of the rotor 3 and the stator 2. The stator in the present embodiment is the same stator 2 as in the first embodiment.

  The rotor 3 has a frame 31, a rotor core 12 and a magnet 13. The configuration of the rotor core 12 and the magnet 13 is the same as that of the first embodiment.

  The frame 31 has a lid 311 and a plurality of wall portions 312. The lid 311 has a substantially cylindrical shape having a top surface, and a hole 311A penetrating in the axial direction is formed at the radial center of the top surface.

  The wall portion 312 protrudes downward from the lower surface of the lid portion 311 and is spaced apart in the circumferential direction. That is, the slits SL are provided between the wall portions 312 adjacent in the circumferential direction.

  The thickness of the lid portion 311 and the thickness of the wall portion 312 may be the same and constant, so that the frame 31 can be formed, for example, by drawing on an iron plate such as carbon steel. Is easy.

  The lid 311 covers the rotor core 12 from above and is mounted on the top surface of the rotor core 12. A shaft (not shown) is fixed to the hole 311A. As described above, the wide portion 121 and the narrow portion 122 are formed on the rotor core 12. The wall portion 312 is disposed at a position covering the narrow portion 122 from the radially outer side. Therefore, the wide portion 121 is disposed between the wall portions 312 adjacent in the circumferential direction. That is, the wide portion 121 is exposed radially outward through the slit SL. The rotor core 12 is fixed to the frame 3 by, for example, an adhesive.

  Thus, the rotor (3) of the present embodiment further includes a frame (31) covering at least a part of the radially outer side of the rotor core (12). This makes it possible to fix the shaft to the frame.

  Further, in the rotor (3) of the present embodiment, the rotor yoke is a rotor core (12) in which a plurality of steel plates are stacked, and the rotor further includes a frame (31). The frame (31) has a lid portion (311) covering the rotor core from one side in the axial direction, and a plurality of wall portions (312) projecting from the lid portion to the other side in the axial direction and aligned in the circumferential direction The wide portion (121) of the rotor core is disposed between the adjacent wall portions.

  Thus, the frame itself can be easily produced, the shaft can be fixed to the frame, and the frame and the rotor core can be easily fixed by the wall. Further, since the outer peripheral surface of the rotor core protrudes between the wall portions, the magnetic circuit characteristics can be improved by protruding as much as possible. Also, the wall portion facilitates the circumferential positioning of the rotor core with respect to the frame.

  Further, the wide width portion (121) gradually widens in radial direction width toward the circumferential direction at positions between circumferential end portions of adjacent magnetic pole portions (13A, 13B, etc.).

<3. Third embodiment>
Next, a rotor and a stator according to a third embodiment of the present invention will be described. FIG. 6 is a perspective view from above showing the configuration of the rotor 4 and the stator 2 according to the third embodiment. FIG. 7 is a perspective view from below showing the configuration of the rotor 4 and the stator 2. FIG. 8 is a plan sectional view in which the rotor 4 and the stator 2 are viewed in the axial direction. The stator in the present embodiment is the same as the stator 2 of the first embodiment.

  The rotor 4 has a frame 41, a rotor core 42, and a plurality of magnets 43. The frame 41 has the same configuration as the frame 31 of the second embodiment, and has a lid 411 and a plurality of walls 412.

  The plurality of magnets 43 are circumferentially spaced along the inner circumferential surface of the rotor core 42. The outer peripheral surface of the magnet 43 and the inner peripheral surface of the magnet 43 both have an arc shape centering on the central axis C. The inner peripheral surface of the rotor core 42 is circular around the central axis C. The entire circumferential direction of the outer peripheral surface of the magnet 43 contacts the inner peripheral surface of the rotor core 42. The magnet 43 is fixed to the inner peripheral surface of the rotor core 42 by an adhesive or the like.

  The rotor core 42 has a wide portion 421 having a wide radial direction width and a narrow portion 422 having a narrow radial direction width. The wide part 421 has a constant radial width in the circumferential direction. Also in the narrow portion 422, the radial width is constant in the circumferential direction. The outer peripheral surface of the wide portion 421 protrudes outward in the radial direction from the outer peripheral surface of the narrow portion 422.

  The circumferential end of the magnet 43 as the magnetic pole portion is located at the wide portion 421. The circumferentially central portion of the magnet 43 is located at the narrow portion 422. Thereby, although the amount of magnetic flux becomes large in the location between magnets 43 adjacent to a peripheral direction, magnetic flux density can be reduced by constituting a wide part. Therefore, the occurrence of magnetic saturation can be prevented, and the motor characteristics can be improved.

  Further, the lid 411 of the frame 41 covers the rotor core 42 from above. On the outer peripheral surface of the rotor core 42, a recess 42A that is recessed radially inward is formed. The recess 42 </ b> A is disposed between the wide portions 421 adjacent in the circumferential direction and is formed by the narrow portions 422. The wall portion 412 is disposed in the recess 42A. That is, the wide portion 421 is disposed between the adjacent wall portions 412. The wall portion 412 is fixed to the rotor core 42 by an adhesive or the like.

  Also in this embodiment, as in the second embodiment, the frame 41 itself can be easily formed, the shaft can be fixed to the frame 41, and the frame 41 and the rotor core 42 can be easily fixed by the wall portion 412. . Further, since the outer peripheral surface of the rotor core 42 protrudes between the wall portions 412, the magnetic circuit characteristics can be improved by protruding as much as possible. Further, the wall portion 412 facilitates the circumferential positioning of the rotor core 42 with respect to the frame 41.

<4. Fourth embodiment>
Next, a rotor and a stator according to a fourth embodiment of the present invention will be described. FIG. 9 is a perspective view from above showing the configuration of the rotor 5 and the stator 2 according to the fourth embodiment. FIG. 10 is a perspective view from below showing the configuration of the rotor 5 and the stator 2. FIG. 11 is a plan sectional view in which the rotor 5 and the stator 2 are viewed in the axial direction. The stator in the present embodiment is the same as the stator 2 of the first embodiment.

  The rotor 5 can rotate around the central axis C in the circumferential direction on the outer circumferential side of the stator 2. Thus, the motor including the rotor 5 and the stator 2 is of the outer rotor type.

  The rotor 5 has a top frame 51, a rotor core 52, and a plurality of magnets 53.

  The top plate frame 51 has a disk shape and is formed of carbon steel or the like. The rotor core 52 is disposed below the top frame 51. The rotor core 52 has a substantially cylindrical shape extending in the axial direction with the radially inner side opened. The rotor core 52 is formed by laminating magnetic steel plates in the axial direction, and corresponds to a rotor yoke.

  The plurality of magnets 53 are arranged circumferentially along the inner circumferential surface of the rotor core 52. The inner circumferential surface of the magnet 53 is arc-shaped around the central axis C. The radial position of the outer peripheral surface of the magnet 53 is positioned radially inward as it goes from the circumferential center position of the magnet 53 to one circumferential end and the other circumferential end.

  The inner circumferential surface of the rotor core 52 contacts the entire circumferential direction of the outer circumferential surface of the magnet 53. The magnet 53 is fixed to the inner peripheral surface of the rotor core 52 by an adhesive or the like. The outer peripheral surface of the rotor core 52 is circular around the central axis C.

  A hole 511 is formed in the radial direction central portion of the top plate frame 51. A shaft (not shown) extending in the axial direction is fixed to the hole 511.

  A gap SP is provided between the magnets 53 adjacent in the circumferential direction. The radially outer side of each magnet 53 is magnetized to either the N pole or the S pole, and the radially inner side is magnetized to a magnetic pole opposite to the radially outer side. The magnetic poles shown in FIG. 11 indicate the magnetic poles that are magnetized radially outward of the respective magnets 53. Thus, the radially outer magnetic poles of the magnets 53 are alternately arranged in the circumferential direction. Each magnet 53 corresponds to a magnetic pole portion that constitutes a magnetic pole.

  In FIG. 11, the magnets 53 adjacent in the circumferential direction are representatively shown as the magnetic pole portions 53A and 53B.

  The outer circumferential surface of the magnetic pole portion 53A is positioned radially inward in the radial direction from the circumferential center position of the magnetic pole portion 53A toward one circumferential end. The outer circumferential surface of the magnetic pole portion 53B is positioned radially inward in the radial direction from the circumferential center position of the magnetic pole portion 53B toward the other circumferential end. As a result, the radial width of the rotor core 52 is increased at the positions where the circumferential end of the magnetic pole portion 53A and the circumferential end of the magnetic pole portion 53B are located, and a wide portion 521 having a wide radial width is formed. Further, the radial width of the rotor core 52 is narrowed at the circumferentially central position of the magnetic pole portions 53A, 53B, and the narrow portion 522 is formed. The same applies to the relationship between the magnetic pole parts other than the magnetic pole parts 53A and 53B and the rotor core 12, so the wide part 521 and the narrow part 522 are formed in the circumferential direction.

  The magnetic flux M is shown in FIG. In the rotor core 52, the magnetic flux M flowing from one to the other of the adjacent magnetic pole portions increases at the portion between the adjacent magnetic pole portions, but since the wide portion 521 is disposed at this portion, the magnetic flux density is Reduced. Therefore, the occurrence of magnetic saturation is prevented, and the magnetic flux from the magnet can be used more effectively. Thereby, the characteristics of the motor including the rotor 5 can be improved.

That is, the rotor according to the present embodiment is a rotor (5) capable of circumferentially rotating the outer peripheral side of the stator (2) around a central axis (C) extending in the vertical direction, and a plurality of magnetic poles are circumferential Magnets (53) alternately located on the outer surface of the magnet, and a rotor yoke (52) disposed on the outer peripheral side of the magnets;
Equipped with The rotor yoke (52) includes at least a wide portion (521) having a wider radial direction and a narrow portion (522) having a narrower radial direction than the wide portion. In the magnetic pole parts (53A, 53B, etc.) constituting the magnetic pole, the circumferential central part of the magnetic pole part is located at the narrow width part, and the circumferential end part of the magnetic pole part is located at the wide width part.

  According to such a configuration, the magnetic flux density is reduced and the occurrence of magnetic saturation is prevented by widening the radial width of the rotor yoke at circumferential positions between the magnetic pole portions where the amount of magnetic flux by the magnet becomes large. . Therefore, the magnetic flux from the magnet can be used more effectively, and the motor characteristics can be improved.

  The rotor yoke is a rotor core (52) in which a plurality of steel plates are stacked. The rotor core is formed by axially laminating steel plates formed by punching using a press, so that the shape including the wide portion and the narrow portion can be easily formed.

  The outer peripheral surface of the magnet (53) is positioned radially inward in the radial direction from the circumferential center position of the magnetic pole portion toward the circumferential end, and the inner peripheral surface of the rotor yoke (52) is It contacts with the whole peripheral direction of the peripheral face of the magnet.

  Thus, the radial width of the rotor yoke can be gradually increased as it is separated from the circumferential center position of the magnetic pole portion in the circumferential direction.

  Further, the outer peripheral surface of the rotor yoke (52) has an arc shape centered on the central axis. Thereby, the rotor outer diameter can be prevented from increasing.

  The top plate frame 51 is fixed to the rotor core 52 by a plurality of rivets R. The rivet R penetrates the top plate frame 51 and the rotor core 52 in the axial direction. The rivet R is disposed at the circumferential center position of each magnet 53. That is, the rotor (5) further includes a fixing member (R) inserted in the rotor yoke (52) in the axial direction, and the fixing member is disposed at the circumferential center position of the magnetic pole portions (53A, 53B, etc.) Be done.

  Thereby, since the magnetic flux is small at the circumferentially central position of the magnetic pole portion, the influence of the fixing member on the flow of the magnetic flux can be suppressed.

<5. Fifth embodiment>
Next, a rotor and a stator according to a fifth embodiment of the present invention will be described. FIG. 12 is a perspective view from above showing the configuration of the rotor 6 and the stator 2 according to the fourth embodiment. FIG. 13 is a perspective view from below showing the configuration of the rotor 6 and the stator 2. The stator in the present embodiment is the same as the stator 2 of the first embodiment.

  The rotor 6 has a frame 61, a rotor core 52, and a plurality of magnets 53. The rotor core 52 and the magnet 53 are the same as in the fourth embodiment.

  The frame 61 has a top surface portion 611 and a wall portion 612. The top surface portion 611 has a disk shape. The wall portion 612 is formed to project downward from the entire outer edge of the top surface portion 611. That is, the wall portion 612 extends in a band shape in the circumferential direction.

  The top surface portion 611 covers the rotor core 52 from above. The inner circumferential surface of the wall portion 612 is circular around the central axis C, and contacts the outer circumferential surface of the rotor core 52 over the entire circumferential direction. The outer peripheral surface of the rotor core 52 is fixed to the inner peripheral surface of the wall portion 612 by, for example, an adhesive.

  A hole 611A is formed at the center of the top surface 611 in the radial direction. A shaft (not shown) is fixed to the hole 611A.

  The frame 61 can be formed, for example, by drawing an iron plate such as carbon steel, and the forming becomes easy.

  Also in the present embodiment, since the rotor core 52 has the wide portion 521, the motor characteristics can be improved by preventing the magnetic saturation as in the fourth embodiment.

<6. About Fixing Frame to Rotor Core>
Among the embodiments described above, in the embodiments using the frame, that is, the second, third and fifth embodiments, the frame may be fixed to the rotor core as follows.

  FIG. 14 is a schematic partial vertical cross-sectional view of the frame F and the rotor core RC, and shows a state in which the frame F is radially fixed to the rotor core RC by caulking. In a part of the outer peripheral surface of the rotor core RC, a recess 70 is formed which is recessed inward in the radial direction. The frame F is provided with a cut 71 at a part of the axially extending wall. Then, the frame 71 is fixed to the rotor core RC by the section 71 being bent and stored in the recess 70. That is, the recess 70 and the segment 71 are an example of a fixing portion that fixes the frame F to the rotor core RC in the radial direction.

  That is, in the second embodiment, the section 71 is provided on the wall portion 312 of the frame 31, and the recess 70 is provided on the rotor core 12. Thus, the section 71 is accommodated in the recess 70 provided in the narrow portion 122. Therefore, the segment 71 is disposed at the circumferential center position of the magnet 13.

  In the third embodiment, the section 71 is provided on the wall portion 412 of the frame 41, and the recess 70 is provided on the rotor core 42. Thus, the section 71 is accommodated in the recess 70 provided in the narrow portion 422. Therefore, the segment 71 is disposed at the circumferential center position of the magnet 43.

  In the case of the fifth embodiment, the section 71 is provided on the wall portion 612 of the frame 61, and the recess 70 is provided on the rotor core 52. At this time, the recess 70 is provided in the narrow portion 522. Therefore, the segment 71 is disposed at the circumferential center position of the magnet 53.

  That is, the fixing portions (70, 71) for fixing the frame in the radial direction to the rotor core are disposed at the circumferential center position of the magnetic pole portion. As a result, since the amount of magnetic flux is small at a circumferentially central position of the magnetic pole portion in the rotor core, the influence of the fixing portion on the flow of magnetic flux can be suppressed.

  In addition, the said fixing | fixed part may be a fixing | fixed part which performs pinning in addition, for example.

<7. Fixing of magnetic steel sheet in rotor core>
Further, in the embodiment described above, the rotor core is configured by laminating the magnetic steel plates in the axial direction, but the magnetic steel plates adjacent in the axial direction may be fixed by caulking. More specifically, of the adjacent magnetic steel plates, the downward protruding portion of the upper magnetic steel plate is accommodated in the downward protruding portion of the other magnetic steel plate, and the upper and lower magnetic steel plates are axially It is fixed in the direction.

  The crimped portion, which is the convex portion, is disposed at the circumferential center position of the magnet. That is, the caulking part which fixes steel plates which adjoin axial direction is arrange | positioned in the circumferential direction center position of a magnetic pole part. As a result, since the amount of magnetic flux is small at the circumferential center position of the magnetic pole portion in the rotor core, the influence of the crimped portion on the flow of magnetic flux can be suppressed.

<8. Other>
The embodiment has been described above, but various modifications can be made within the scope of the present invention.

  For example, in the embodiment described above, although the magnet was plural, the magnet may be single. For example, FIG. 15 shows an example in which the magnet is changed to a single in the configuration of FIG. 3 (the first embodiment) described above.

  In the rotor shown in FIG. 15, a single magnet 130 is provided. The magnet 130 is annular when viewed from the axial direction. The magnet 130 has a plurality of magnetic pole portions arranged side by side in the circumferential direction. FIG. 15 representatively shows the magnetic pole portions 130A to 130C.

  The magnetic poles shown in FIG. 15 indicate the magnetic poles magnetized radially outward of the respective magnetic pole portions. The opposite magnetic poles are magnetized in the radially outer side and the radially inner side of each magnetic pole portion. And the magnetic pole of the radial direction outer side of a magnetic pole part is alternately arrange | positioned to the circumferential direction.

  The circumferentially central portion of the magnetic pole portion is located at the narrow portion 122 of the rotor core 12. The circumferential end of the magnetic pole portion is located at the wide portion 121 of the rotor core 12. As a result, although the amount of magnetic flux increases at locations where the magnetic pole portions in the rotor core 12 are adjacent to each other, the magnetic flux density can be reduced by the wide portions 121, and magnetic saturation can be prevented.

  Further, the rotor core may not necessarily be provided on the rotor. That is, a frame having the shape of the rotor core 12, 42, 52 described above and further having a lid may be provided on the rotor. In this case, the frame corresponds to the rotor yoke.

  The present invention can be used for an outer rotor type motor mounted on any device.

  DESCRIPTION OF SYMBOLS 1 ... Rotor 11, 11 ... Top-plate flame | frame 12 ... Rotor core, 121 ... Wide part, 122 ... Narrow part, 13 ... Magnet, 13A-13C ... Magnetic pole part, 2 ... Stator, 21 ... Stator core, 211 ... Core back, 212 ... Tees, 22 ... Insulator, 23 ... Coil, 3 ... Rotor, 31 ... Frame, 311 ... Lid part, 312 ... Wall part, 4 ... Rotor, 41 ... Frame, 411 ... Lid part, 412 ... Wall part, 5 ... Rotor, 51 ... Heaven Board frame 52, Rotor core, 521: Wide part, 522: Narrow part, 53: Magnet, 53A, 53B: Magnetic pole part, 6: Rotor, 61: Frame · · · · · · · · · · · · 411 top surface portion, 612 · · · wall portion, 70 · · · recessed portion, 71 · · Sections 130 ... magnet, 130A to 130C ... magnetic pole portions, R ... rivet, SL ... slit, C ... central axis, M ... flux

Claims (12)

A rotor capable of circumferentially rotating an outer peripheral side of a stator about a central axis extending in the vertical direction,
A magnet having a plurality of magnetic poles alternately positioned in the circumferential direction;
A rotor yoke disposed on an outer peripheral side of the magnet;
Equipped with
The rotor yoke includes at least a wide portion having a large radial width, and a narrow portion having a radial width narrower than the wide portion.
In the magnetic pole portion constituting the magnetic pole,
The circumferentially central portion of the magnetic pole portion is located at the narrow portion,
A rotor, wherein a circumferential end of the magnetic pole portion is located at the wide portion.   The rotor according to claim 1, wherein the rotor yoke is a rotor core in which a plurality of steel plates are stacked.   The rotor according to claim 2, further comprising a frame covering at least a part of the radially outer side of the rotor core.   The rotor according to any one of claims 1 to 3, wherein an outer peripheral surface of the wide portion protrudes radially outward relative to an outer peripheral surface of the narrow portion. The rotor yoke is a rotor core in which a plurality of steel plates are stacked,
Further equipped with a frame,
The frame is
A lid covering the rotor core from one side in the axial direction;
And a plurality of wall portions protruding from the lid portion to the other side in the axial direction and aligned in the circumferential direction,
The rotor according to claim 4, wherein the wide portion of the rotor core is disposed between the adjacent walls.   The rotor according to claim 5, wherein the wide portion gradually widens in radial direction toward the circumferential direction at positions between circumferential ends of the adjacent magnetic pole portions.   The rotor according to claim 5, wherein the wide portion has a radial width which is constant in a circumferential direction. The outer circumferential surface of the magnet is positioned radially inward in the radial direction from the circumferential center position of the magnetic pole portion toward the circumferential end.
The rotor according to any one of claims 1 to 3, wherein the inner circumferential surface of the rotor yoke contacts the entire circumferential direction of the outer circumferential surface of the magnet.   The rotor according to claim 8, wherein the outer peripheral surface of the rotor yoke has an arc shape centered on a central axis. The rotor yoke further includes a fixing member axially inserted into the rotor yoke,
The rotor according to claim 1, wherein the fixing member is disposed at a circumferential center position of the magnetic pole portion.   The rotor according to claim 3, wherein a fixing portion for fixing the frame in the radial direction to the rotor core is disposed at a circumferential center position of the magnetic pole portion.   The rotor according to claim 2, wherein the caulking portion that fixes the steel plates axially adjacent to each other is disposed at a circumferential center position of the magnetic pole portion.

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