JP2016208790A - Motor and centrifugal blower - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of the structure of a stator having a small number of teeth in which the gap between the wall portion of an insulator and a core back is narrow and thus a work of winding a conducting wire is wound around the teeth through the insulator is remarkably difficult.SOLUTION: A stator of a motor has a plurality of core pieces arranged in the circumferential direction, an insulator 70 is secured to the core pieces, and a conducting wire is wound around the insulator 70. The insulator 70 has an inner wall portion 72 which is located inside the coil in the radial direction and expands substantially perpendicular to the radial direction. The inner wall portion 72 has a pair of axial end edges 721, a pair of circumferential end edges 722, and four corner portions 723 positioned at the boundaries between the axial end edges 721 and the circumferential end edges 722. Each corner portion 723 is located in a region on the teeth side of virtual lines obtained by extending the axial direction end edge 721 and the circumferential direction end edge 722 when viewed from the inside in the radial direction.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a motor and a centrifugal blower.

  2. Description of the Related Art Conventionally, a so-called inner rotor type motor in which a rotor is disposed on the radially inner side of a stator is known. In the inner rotor type motor, the stator core has an annular core back and a plurality of teeth protruding radially inward from the core back. In this type of motor, an annular stator core may be formed by combining a plurality of core pieces (so-called “divided cores”) having one tooth. In that case, at the time of manufacture of a motor, an insulator is attached to each core piece, and a coil is formed for every core piece by winding a conducting wire around the insulator.

A conventional example of an inner rotor type motor using a split core is described in, for example, Japanese Patent Application Laid-Open No. 2014-225968.
JP 2014-225968 A

  A motor for high-speed rotation used in a vacuum cleaner or the like may be designed with a small number of teeth in order to reduce the number of times the drive current is switched. However, if the number of teeth is small, the center angle per core piece increases, and therefore the core back is greatly curved in each core piece. On the other hand, the insulator has a bulging wall portion in the vicinity of the radially inner end portion to prevent the coil from collapsing. For this reason, in the structure of the stator with a small number of teeth, the gap between the wall portion of the insulator and the core back is narrowed. If it does so, the operation | work which winds conducting wire around an insulator via an insulator at the time of manufacture will become very difficult.

  An object of the present invention is to provide a structure that facilitates winding of a conductor in an inner rotor type motor having a plurality of core pieces.

  An exemplary first invention of the present application includes: a shaft disposed along a central axis that extends vertically; a rotor that rotates about the central axis together with the shaft; and a stator disposed around the rotor. And the stator is made of a magnetic material, and includes a plurality of core pieces arranged in a circumferential direction, an insulator attached to each of the plurality of core pieces, and a conductive wire wound around each of the plurality of insulators. Each of the plurality of core pieces has a core back extending in the circumferential direction and teeth projecting radially inward from the core back, and the plurality of core backs are annular. And the plurality of insulators are respectively connected to the teeth insulating portion interposed between the teeth and the coil, and the coil. An inner wall portion that is located radially inward and extends substantially perpendicular to the radial direction, and the inner wall portion includes a pair of axial edges located at both ends in the axial direction, and a circumferential direction. A pair of circumferential edges located at both ends, and four corners located at the boundary between the axial edge and the circumferential edge, and viewed from the radially inner side, the corner The part is a motor located in a region on the teeth side with respect to an imaginary line obtained by extending the axial end edge and the circumferential end edge.

  According to the first exemplary invention of the present application, the insulator has corner portions located in the regions on the teeth side of the imaginary lines extending the axial end edge and the circumferential end edge at the four corners of the inner wall portion. Have. For this reason, when winding a conducting wire around an insulator, an inner wall part is not easily obstructed. Therefore, the winding work of the conducting wire can be easily performed.

FIG. 1 is a longitudinal sectional view of a centrifugal blower. FIG. 2 is a top view of the stator. FIG. 3 is a top view of the core piece. FIG. 4 is a top view of the insulator. FIG. 5 is a perspective view of the insulator. FIG. 6 is a perspective view of the insulator. FIG. 7 is a view of the insulator as viewed from the radially inner side. FIG. 8 is a view of an insulator according to a modification as viewed from the inside in the radial direction.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, the direction parallel to the central axis of the centrifugal blower is referred to as “axial direction”, the direction orthogonal to the central axis of the centrifugal blower is referred to as “radial direction”, and the direction along the circumference centered on the central axis of the centrifugal blower is defined. These are referred to as “circumferential directions”, respectively. Further, in the present application, the shape and positional relationship of each part will be described with the axial direction as the vertical direction and the impeller side as the upper side with respect to the motor. However, the definition of the vertical direction is not intended to limit the orientation of the motor and the centrifugal blower during manufacture and use.

<1. Centrifugal blower configuration>
FIG. 1 is a longitudinal sectional view of a centrifugal blower 1 according to an embodiment. The centrifugal blower 1 is a turbo centrifugal fan that sucks upward air from an intake hole provided in an upper portion and discharges the air downward. A turbo centrifugal fan is more efficient and has less noise than a sirocco centrifugal fan.

  Centrifugal blower 1 of this embodiment is provided in a vacuum cleaner, for example, and is used in order to produce suction power to a vacuum cleaner. However, the centrifugal blower of the present invention may be used for applications other than the vacuum cleaner. For example, it is installed in other blower devices such as range hood fans and air supply and exhaust devices used for building ducts, home appliances, medical devices, industrial large equipment, etc., and performs intake and exhaust Also good.

  As shown in FIG. 1, the centrifugal blower 1 includes a motor 11, an impeller 12, and a blower casing 13. The rotating part 30 and the impeller 12 described later of the motor 11 rotate about the central axis 9.

  The motor 11 is an inner rotor type brushless DC motor. The motor 11 has a stationary part 20 and a rotating part 30. The stationary part 20 is relatively stationary with respect to the blower casing 13. The rotating unit 30 is supported to be rotatable about the central axis 9 with respect to the stationary unit 20.

  The stationary part 20 includes a stator 21, a motor cover 22, a bottom plate 23, a circuit board 24, an upper bearing 25 and a lower bearing 26. The rotating unit 30 includes a shaft 31 and a rotor 32.

  The stator 21 generates magnetic flux according to the drive current supplied from the circuit board 24. The stator 21 is disposed around a rotor 32 described later. The stator 21 includes a plurality of core pieces 60, a plurality of insulators 70, and a plurality of coils 80.

  The plurality of core pieces 60 are annularly arranged around the central axis 9. Each core piece 60 includes a core back 61 extending in the circumferential direction and a tooth 62 protruding from the core back 61 inward in the radial direction. The insulator 70 is attached to each core piece 60. The coil 80 is constituted by a conductive wire wound around the teeth 62 via an insulator 70. A more detailed structure of the stator 21 will be described later.

  The motor cover 22 is a resin member that holds the stator 21. The motor cover 22 includes an upper plate part 221, a side plate part 222, a first fixing part 223, a second fixing part 224, and at least one bottom plate fixing part 225.

  The upper plate portion 221 is a plate-like portion that extends substantially perpendicular to the central axis 9 above the stator 21. A through hole is formed in the approximate center of the upper plate portion 221. An upper bearing 25 is held in the through hole of the upper plate portion 221. The side plate part 222 has a substantially cylindrical shape and extends downward in the axial direction from the outer edge of the upper plate part 221.

  The bottom plate fixing portion 225 protrudes radially outward from the vicinity of the lower end portion of the side plate portion 222. The bottom plate fixing portion 225 is formed with at least one screw hole. The bottom plate 23 is fixed to the bottom plate fixing portion 225 by screwing. In the motor 11 of the present embodiment, the bottom plate fixing portions 225 are provided at three locations in the circumferential direction. However, the number of fixing points between the motor cover 22 and the bottom plate 23 is not limited to three, and may be two or four or more. Further, the motor cover 22 and the bottom plate 23 may be fixed by other methods such as adhesion and caulking. In addition, the structure of the 1st fixing | fixed part 223 and the 2nd fixing | fixed part 224 is mentioned later.

  The bottom plate 23 is a member that covers at least a part of the opening below the motor cover 22. The bottom plate 23 extends substantially perpendicular to the central axis 9. A recess is formed in the center of the bottom plate 23. A lower bearing 26 is held in the recess of the bottom plate 23. The stator 21, the circuit board 24, the upper bearing 25, the lower bearing 26, and the rotor 32 are accommodated in a housing constituted by the motor cover 22 and the bottom plate 23.

  In the present embodiment, the circuit board 24 has a substantially plate shape. The circuit board 24 is disposed substantially perpendicular to the central axis 9 below the stator 21. On the circuit board 24, electronic components constituting an electric circuit for supplying a drive current to the coil 80 are mounted. The ends of the conductive wires constituting the coil 80 are electrically connected to an electric circuit on the circuit board 24.

  The upper bearing 25 supports the shaft 31 to be rotatable with respect to the motor cover 22. The lower bearing 26 rotatably supports the shaft 31 with respect to the bottom plate 23. As the upper bearing 25 and the lower bearing 26, for example, ball bearings in which spherical rolling elements are interposed between an inner ring and an outer ring are used. An elastic member 27 is interposed between the motor cover 22 and the upper bearing 25. Thereby, the vibration at the time of rotation of the motor 11 and the impeller 12 is reduced. In addition, as the upper bearing 25 and the lower bearing 26, types of bearings other than ball bearings may be used.

  The shaft 31 is disposed along the central axis 9 extending vertically. More specifically, the shaft 31 is a columnar member disposed along the central axis 9. The shaft 31 is supported by the upper bearing 25 and the lower bearing 26 and can rotate around the central axis 9. The upper end portion of the shaft 31 protrudes above the motor cover 22. The impeller 12 is fixed to the upper end portion of the shaft 31. In the present embodiment, the impeller 12 is directly fixed to the shaft 31, but the impeller 12 is indirectly connected to the shaft 31 via another member such as a cylindrical member made of a resin material or a metal material. It may be fixed to.

  The rotor 32 is fixed to the shaft 31 and rotates around the central axis 9 together with the shaft 31. The rotor 32 of the present embodiment is made of magnet resin formed in a substantially cylindrical shape. On the outer peripheral surface of the rotor 32, N poles and S poles are alternately magnetized in the circumferential direction. Further, the outer peripheral surface of the rotor 32 faces the end surface on the radially inner side of the teeth 62 in the radial direction with a slight gap therebetween. That is, the rotor 32 has a magnetic pole surface that faces the stator 21 in the radial direction.

  In this embodiment, the magnet resin rotor 32 is used. However, the rotor 32 may be one in which a plurality of magnets are fixed to the outer peripheral surface or inside of a cylindrical rotor core that is a magnetic body. Good.

  When the motor 11 is driven, a drive current is supplied from the power source to the coil 80 via the electric circuit on the circuit board 24, and a magnetic flux is generated in the plurality of teeth 62. Thereby, circumferential torque is generated by the action of the magnetic flux between the teeth 62 and the rotor 32. As a result, the rotating unit 30 rotates about the central axis 9. And the impeller 12 rotates with rotation of the rotation part 30.

  The impeller 12 is a so-called turbo centrifugal impeller. The impeller 12 is disposed above the motor cover 22 of the motor 11. As shown in FIG. 1, the impeller 12 has an upper shroud 51, a lower shroud 52, and a plurality of blades 53.

  The upper shroud 51 includes a cylinder portion 511, a skirt portion 512, and an intake hole 513. The upper shroud 51 is disposed above the lower shroud 52 and the plurality of blades 53.

  The cylindrical part 511 is a substantially cylindrical part centering on the central axis 9. The cylindrical portion 511 of the present embodiment has a substantially constant diameter regardless of the position in the axial direction. The cylindrical portion 511 may have a shape that gradually increases in diameter as it goes downward in the axial direction.

  The skirt portion 512 extends radially outward from the lower end portion of the cylindrical portion 511. The radial position of the outer edge of the skirt 512 is substantially the same as the radial position of the outer edge of the lower shroud 52. The intake hole 513 is disposed at the center of the upper shroud 51. The intake hole 513 is formed by the cylindrical portion 511 and penetrates the upper shroud 51 in the axial direction on the radially inner side of the cylindrical portion 511.

  The lower shroud 52 is a plate-like portion that extends substantially perpendicular to the central axis 9 above the motor cover 22. The lower surface of the lower shroud 52 faces the upper surface of the motor cover 22 in the axial direction. The lower shroud 52 is fixed to the shaft 31 of the motor 11 at its radially inner end.

  In the axial direction, the blade 53 is disposed between the upper shroud 51 and the lower shroud 52. The plurality of blades 53 are arranged at substantially equal intervals in the circumferential direction. When the centrifugal blower 1 is driven, the gas between the upper shroud 51 and the lower shroud 52 is accelerated radially outward by the plurality of blades 53.

  The blower casing 13 includes a top plate portion 131 and a wall portion 132. The top plate 131 is disposed above the impeller 12 and extends in an annular shape along the upper surface of the upper shroud 51. The top plate portion 131 has a central hole 130 at the center thereof. The central hole 130 is connected to the intake hole 513 described above. The wall 132 extends downward in a cylindrical shape from the top plate 131 on the radially outer side of the motor 11. At least the upper end of the motor 11 and the impeller 12 are accommodated inside the wall portion 132 in the radial direction. That is, the wall 132 surrounds at least a part of the motor 11. The inner surface of the wall 132 faces at least a part of the motor 11 in the radial direction.

  The blower casing 13 of the present embodiment is formed from three annular members of an upper casing 133, a central casing 134, and a lower casing 135. The central casing 134 is disposed below the upper casing 133. Further, the lower casing 135 is disposed below the central casing 134. The upper casing 133 includes the top plate part 131 and the upper end of the wall part 132. The central casing 134 and the lower casing 135 are cylindrical members that form the wall portion 132. Although the blower casing 13 of this embodiment is formed of three members, the blower casing 13 may be formed of one member, or may be formed of two or four or more members. That is, the blower casing 13 is formed from at least one member.

  The outer peripheral surface of the motor cover 22 and the inner peripheral surface of the wall portion 132 of the blower casing 13 are arranged with a gap in the radial direction. A space between the outer peripheral surface of the motor cover 22 and the inner peripheral surface of the wall 132 serves as a gas flow path 10 when the centrifugal blower 1 is driven. At least a part of the channel 10 is connected to the exhaust hole of the wall 132.

  When the centrifugal blower 1 is driven, a drive current is supplied to the stator 21 of the motor 11, and the rotating unit 30 and the impeller 12 of the motor 11 rotate. When the impeller 12 rotates, the gas above the blower casing 13 is sucked through the central hole 130 of the blower casing 13 and the intake hole 513 of the impeller 12 as indicated by solid arrows in FIG. And the lower shroud 52 are discharged to the radially outer side of the impeller 12.

  As shown in FIG. 1, the gas discharged to the radially outer side of the impeller 12 strikes the wall portion 132 of the blower casing 13 and changes its direction downward, so that the outer peripheral surface of the motor cover 22 and the inner periphery of the wall portion 132 are changed. It progresses in the axial direction downward in the flow path 10 formed between the surfaces. Then, the airflow is discharged from the lower end portion of the flow path 10 to the outside of the centrifugal blower 1 through the exhaust hole.

<2. About Stator>
Subsequently, a more detailed structure of the stator 21 will be described. FIG. 2 is a top view of the stator 21. As shown in FIG. 2, the stator 21 according to the present embodiment includes three core pieces 60, three insulators 70, and three coils 80. With this configuration, the number of energizations of the windings per rotation can be reduced, so that the motor can be driven at high speed.

  FIG. 3 is a top view of the core piece 60. The plurality of core pieces 60 are made of a magnetic material and are arranged in the circumferential direction. For the core piece 60, for example, a laminated steel plate in which electromagnetic steel plates that are magnetic bodies are laminated in the axial direction is used. As shown in FIG. 3, the core piece 60 has a core back 61 and teeth 62. The core back 61 extends in the circumferential direction on the radially outer side than the teeth 62. However, the shape of the core back 61 in a top view does not necessarily need to be an arc shape, and may be extended in the circumferential direction as a whole. The teeth 62 protrude from the center in the circumferential direction of the core back 61 toward the inside in the radial direction.

  The core back 61 of this embodiment includes a central core back portion 611 and a pair of connection core back portions 612. The central core back portion 611 extends substantially perpendicular to the teeth 62 extending in the radial direction. Further, the center core back portion 611 extends from the radially outer end of the tooth 62 toward both sides in the circumferential direction. The pair of connecting core back portions 612 are located on both sides of the central core back portion 611 in the circumferential direction. Each connecting core back portion 612 extends from the circumferential end portion of the central core back portion 611 while being bent in a direction approaching the teeth 62.

  Thus, in the present embodiment, one tooth 62 is provided for each of the three core pieces 60. For this reason, the number of the teeth 62 which the stator 21 has is the minimum three as a three-phase synchronous motor. If the number of teeth 62 is reduced, the number of switching operations per rotation of the motor drive circuit during driving can be reduced. Therefore, it becomes easy to make the motor 11 correspond to high speed.

  As shown in FIG. 2, the three core pieces 60 are arranged in the circumferential direction. The core backs 61 of the three core pieces 60 are connected in an annular shape. Specifically, the ends of the connecting core back portions 612 of the adjacent core pieces 60 are connected to each other. The joint of the core piece 60 is fixed by welding, for example.

  The core back 61 of each core piece 60 is provided with a fixing hole 63 penetrating in the axial direction. That is, in this embodiment, all the core pieces 60 each have the fixing hole 63. With this configuration, all the core pieces 60 can be firmly fixed to the motor cover 22 when the centrifugal blower 1 is assembled. The fixing hole 63 is located outside the teeth 62 in the radial direction. The vicinity of the center in the circumferential direction of the core back 61 is a portion where the magnetic flux density when driving the motor 11 is low and the role as a magnetic path is small. By providing the fixing hole 63 at the location, the narrowing of the magnetic path by the fixing hole 63 is suppressed.

  The motor cover 22 and the core piece 60 are fixed by a fixing member inserted into the fixing hole 63. As shown in FIG. 1, the motor cover 22 has three first fixing portions 223 and three second fixing portions 224. Each of the three first fixing portions 223 protrudes inward in the radial direction from the side plate portion 222 above the fixing hole 63 described above. The second fixing portion 224 protrudes radially inward from the side plate portion 222 below the fixing hole 63 described above. The first fixing part 223 and the second fixing part 224 are each provided with a screw hole extending in the axial direction. At the time of manufacturing the motor 11, screws 43 as fixing members are inserted into the screw holes of the second fixing portion 224, the fixing holes 63, and the screw holes of the first fixing portion 223 at three locations in the circumferential direction. Thereby, the stator 21 and the motor cover 22 are fixed. With this configuration, the motor cover 22 and the core piece 60 can be firmly fixed.

  Note that the number of fixing points between the stator 21 and the motor cover 22 is not necessarily three. For example, the fixing hole 63 may be provided in only one or two of the three core pieces 60. Each core piece 60 may be provided with two or more fixing holes 63. Further, the fixing method of the stator 21 and the motor cover 22 may be a method other than screwing. For example, the stator 21 and the motor cover 22 may be fixed by resin-molding the motor cover 22 using the stator 21 as an insert part.

  The insulator 70 is attached to each of the plurality of core pieces 60. As a material of the insulator 70, a resin which is an insulator is used. FIG. 4 is a top view of the insulator 70. 5 and 6 are perspective views of the insulator 70. FIG. As shown in FIGS. 4 to 6, the insulator 70 has a teeth insulating portion 71, an inner wall portion 72, and an outer wall portion 73. The teeth insulating portion 71 covers the upper surface, the lower surface, and both end surfaces of the tooth 62 in the circumferential direction. The inner wall portion 72 is located radially inward of the coil 80 and extends substantially perpendicular to the radial direction. The inner wall portion 72 extends outward from the radially inner end of the tooth insulating portion 71 substantially perpendicular to the radial direction. The outer wall portion 73 extends outward from the end portion on the radially outer side of the teeth insulating portion 71 substantially perpendicularly to the radial direction.

  The coil 80 is configured by a conductive wire wound around each of the plurality of insulators 70. The coil 80 is formed by winding a conductive wire around the teeth insulating portion 71 of the insulator 70. Between the coil 80 and the tooth 62, a tooth insulating portion 71 is interposed. Thereby, the coil 80 and the teeth 62 are electrically insulated. The inner wall portion 72 is located on the radially inner side of the coil 80. Thereby, the coil 80 is prevented from collapsing inward in the radial direction. Moreover, it can prevent that the coil 80 and the rotor 32 contact. The outer wall portion 73 is located on the radially outer side of the coil 80. Thereby, the coil 80 is prevented from collapsing outward in the radial direction.

  In addition, as shown in FIG. 2, the three insulators 70 are arrange | positioned at intervals in the circumferential direction. Therefore, in this embodiment, the joint of the three core backs 61 is exposed from the insulator 70. For this reason, at the time of manufacture of the stator 21, after attaching the insulator 70 and the coil 80 to each core piece 60, the edge parts of the connection core back part 612 of each core piece 60 can be fixed by welding etc.

  As shown in FIGS. 5 and 6, the insulator 70 of the present embodiment includes an upper insulator piece 701 and a lower insulator piece 702. The upper insulator piece 701 covers the core piece 60 from above. The lower insulator piece 702 covers the core piece 60 from the lower side. The upper insulator piece 701 and the lower insulator piece 702 are fixed to each other by winding a conductive wire around the teeth insulating portion 71 formed by both pieces.

  As shown in an enlarged manner in FIG. 5, the lower end portion of the upper insulator piece 701 and the upper end portion of the lower insulator piece 702 are in contact with each other on a contact surface inclined with respect to the axial direction. Thereby, the upper insulator piece 701 and the lower insulator piece 702 are fixed while being positioned with high accuracy. In addition, a concave portion or a convex portion that can be engaged with each other may be formed at the lower end portion of the upper insulator piece 701 and the upper end portion of the lower insulator piece 702. The upper insulator piece 701 may be positioned by the lower insulator piece 702 and the concave portion or the convex portion.

  FIG. 7 is a view of the insulator 70 as seen from the inside in the radial direction. As shown in FIGS. 5 to 7, the inner wall portion 72 of the insulator 70 includes a pair of axial end edges 721, a pair of circumferential end edges 722, and four corner portions 723. The pair of axial edges 721 are located at both axial ends of the inner wall 72. Each axial edge 721 extends in the circumferential direction at a certain axial position. The pair of circumferential end edges 722 are located at both ends in the circumferential direction of the inner wall portion 72. Each circumferential edge 722 extends in the axial direction at a constant circumferential position. The four corners 723 are located at the boundary between the axial end edge 721 and the circumferential end edge 722.

  The corner portion 723 of the present embodiment is an arc-shaped curved surface as viewed from the inside in the radial direction. However, the above-mentioned “arc shape” does not necessarily have to be a part of a perfect circle centered on one point, and includes a substantially arc shape. With this configuration, when the motor 11 is assembled, the work of winding the conductor wire around the insulator 70 becomes easier. Details will be described later.

  As shown in an enlarged view in FIG. 7, when viewed from the inside in the radial direction, the corner portion 723 is located in a region closer to the teeth 62 than the virtual line 91 obtained by extending the axial end edge 721 and the circumferential end edge 722, respectively. To position. More specifically, when viewed from the inside in the radial direction, an imaginary line 91 obtained by extending the circumferential end of the axial end edge 721 in the circumferential direction, and an axial end of the circumferential end edge 722 in the axial direction The extended virtual lines 92 intersect each other. The corner portion 723 is located in a region on the tooth 62 side among regions divided by the virtual lines 91 and 92. The remaining three corner portions 723 of the inner wall portion 72 are also arranged in the same positional relationship with respect to the adjacent axial end edge 721 and circumferential end edge 722, respectively. With this configuration, when the conductor is wound around the insulator 70 using a winding machine or the like, the inner wall portion 72 is unlikely to be an obstacle to the track of the winding machine. Therefore, the coil 80 can be easily formed. In addition, when winding a conducting wire without using a winding machine, the coil 80 can be easily formed by adopting the above configuration. Details will be described later.

Here, as shown in FIG. 7, the axial distance from the upper end in the axial direction of the inner wall portion 72 to the lower end in the axial direction is A. A circumferential distance from one circumferential end of the inner wall portion 72 to the other circumferential end is defined as B. The distance A is longer than the axial length at the radially inner end of the tooth 62. The distance B is longer than the circumferential length at the inner end of the tooth 62. Further, C is the maximum distance from the center point O in the axial direction and the circumferential direction of the tooth 62 to the corner portion 723 when viewed from the inside in the radial direction. Then, this insulator 70 satisfies the relationship of the following formula (1).
C ² <(A / 2) ² + (B / 2) ² (1)

  When manufacturing the stator 21, first, the insulator 70 is attached to each core piece 60. Thereafter, the conductive wire is wound around the teeth insulating portion 71 of the insulator 70. At that time, the winding device makes the nozzle that feeds the lead wire approach from the inside in the radial direction of the insulator 70, and winds the lead wire around the teeth insulating portion 71 of the insulator 70 as shown by the broken line arrow in FIG. . At that time, it is necessary to relatively rotate the core piece 60, the insulator 70, and the nozzle with respect to the conductive wire while avoiding the inner wall portion 72 of the insulator 70.

  As described above, the insulator 70 has the corners 723 located in the region closer to the teeth 62 than the virtual lines obtained by extending the axial end edge 721 and the circumferential end edge 722 at the four corners of the inner wall portion 72. As a result, the maximum distance C from the center point O of the tooth 62 to the corner portion 723 is shortened when viewed from the inside in the radial direction. For this reason, when winding a conducting wire around the insulator 70, the corner | angular part 723 of the inner side wall part 72 does not become an obstacle with respect to a motion of a nozzle. Therefore, the above-described wire winding operation can be easily performed.

  However, if the corner portion 723 is excessively recessed, the strength of the inner wall portion 72 may be reduced, or the coil 80 may be collapsed radially inward. Therefore, it is preferable that the corner portion 723 is not excessively recessed. Specifically, when viewed from the inside in the radial direction, the distance from the center point O in the axial direction and the circumferential direction of the tooth 62 to the axial end edge 721 is shorter than the distance from the center point O to the corner portion 723. It is preferable. Moreover, it is preferable that the distance from the center point O of the teeth 62 to the circumferential edge 722 is shorter than the distance from the center point O to the corner portion 723. With this configuration, it is possible to prevent the strength of the inner wall portion 72 from being lowered while facilitating the formation of the coil 80. Therefore, the coil 80 can be prevented from collapsing inward in the radial direction.

  As shown in FIG. 4, in this insulator 70, the circumferential length d <b> 1 of the inner wall portion 72 is longer than the radial length d <b> 2 of the teeth insulating portion 71. In the case of such a dimensional relationship, the distance d3 between the circumferential end of the inner wall 72 of the insulator 70 and the radially inner surface of the outer wall 73 is particularly narrow. For this reason, if the corner portion 723 of the inner wall portion 72 is located on the imaginary line extending from the axial end edge 721 and the circumferential end edge 722 or outside the imaginary line, the conductor to the insulator 70 is connected. Winding work becomes particularly difficult. However, in the present embodiment, the corners 723 at the four corners of the inner wall portion 72 are positioned in the region closer to the teeth 62 than the imaginary lines obtained by extending the axial end edge 721 and the circumferential end edge 722, respectively. A conductive wire can be easily wound around 70.

  Further, in this insulator 70, the connecting core back portion 612 of the core back 61 extends from the end portion in the circumferential direction of the central core back portion 611 while being bent in a direction approaching the teeth 62. Thereby, the space | interval d3 of the circumferential direction edge part of the inner wall part 72 of the insulator 70 and the radial direction inner surface of the outer side wall part 73 is especially narrow. For this reason, if the corner portion 723 of the inner wall portion 72 is located on the imaginary line extending from the axial end edge 721 and the circumferential end edge 722 or outside the imaginary line, the conductor to the insulator 70 is connected. Winding work becomes particularly difficult. However, in the present embodiment, the corners 723 at the four corners of the inner wall portion 72 are positioned in the region closer to the teeth 62 than the imaginary lines obtained by extending the axial end edge 721 and the circumferential end edge 722, respectively. A conductive wire can be easily wound around 70.

  As shown in FIG. 6, the outer wall portion 73 of the insulator 70 includes a flat portion 731, a pair of curved portions 732, and a pair of reinforcing portions 733. The flat surface portion 731 is located at the center in the circumferential direction of the outer wall portion 73 and extends substantially perpendicularly and flatly to the teeth 62. The flat surface portion 731 overlaps the inner wall portion 72 in the radial direction. With this configuration, the coil 80 can be prevented from collapsing radially outward. And winding of the conducting wire around the insulator 70 can be performed more easily. The pair of curved portions 732 expand from both ends of the flat portion 731 toward both sides in the circumferential direction. The reinforcing part 733 extends in the radial direction. More specifically, each of the pair of reinforcing portions 733 expands radially outward from the circumferential end of the curved portion 732. With this configuration, the outer wall 73 can be prevented from being bent by the pressure from the coil 80. Therefore, the collapse of the coil 80 toward the radially outer side can be further suppressed.

  The flat surface portion 731 is located on the radially outer side of the coil 80. Therefore, the flat portion 731 prevents the coil 80 from collapsing radially outward. In addition, by making the flat portion 731 flat, a space for arranging the coil 80 can be made wider than in the case where the flat portion 731 is curved in an arc shape. In addition, by providing the reinforcing portions 733 extending in the radial direction at both ends in the circumferential direction of the outer wall portion 73, the strength of the outer wall portion 73 against the radial pressure is improved. Therefore, it is possible to suppress the outer wall portion 73 from being bent by the pressure from the coil 80. As a result, the work of winding the conductive wire around the insulator 70 becomes easier.

<3. Modification>
As mentioned above, although exemplary embodiment of this invention was described, this invention is not limited to said embodiment.

  FIG. 8 is a view of an insulator 70 </ b> A according to one modification as viewed from the inside in the radial direction. In the example of FIG. 8, the corner portion 723 </ b> A is a linear plane when viewed from the inside in the radial direction. Even in such a shape, the maximum distance from the center point O of the tooth to the corner portion 723A is shortened when viewed from the inside in the radial direction. For this reason, when winding a conducting wire around the insulator 70A, the corners of the inner wall portion 72A are unlikely to be an obstacle to the winding work. Therefore, the coil can be easily formed.

  Note that the shape of the corner is not limited to the above-described arc shape and linear shape when teeth are seen in the radial direction from the central axis (that is, when teeth are seen from the radially inner side), but also from an ellipse or a plurality of straight lines. It may be a shape to be formed or a shape in which irregularities are formed, and is not particularly limited as long as the above-described conditions are satisfied.

  Further, the stator core may be constituted by a dust core instead of the electromagnetic steel plate. Moreover, in said embodiment, the number of corner | angular parts is made into four in accordance with the shape of the axial cross section of teeth being a rectangle. However, the number of corners may be changed as appropriate in accordance with the outer shape of the tooth in the axial section. For example, the number of corners may be 1 to 3, or 5 or more.

  Moreover, in said embodiment, the insulator 70 was comprised by two members, the upper insulator piece 701 and the lower insulator piece 702. FIG. However, the insulator 70 may be formed of one member, or may be a combination of three or more members. That is, the insulator 70 only needs to be composed of at least one member.

  Moreover, you may apply the structure equivalent to said embodiment to the motor used for uses other than a cleaner.

  Moreover, about the detailed shape of each member, you may differ from the shape shown by each figure of this application. Moreover, you may combine suitably each element mentioned above in the range by which a contradiction does not arise.

  The present invention can be used for a motor and a centrifugal blower.

DESCRIPTION OF SYMBOLS 1 Centrifugal blower 9 Center axis 10 Flow path 11 Motor 12 Impeller 13 Blower casing 20 Stationary part 21 Stator 22 Motor cover 23 Bottom plate 24 Circuit board 25 Upper bearing 26 Lower bearing 30 Rotating part 31 Shaft 32 Rotor 60 Core piece 61 Core back 62 Teeth 63 Fixed hole 70, 70A Insulator 71 Teeth insulation part 72, 72A Inner wall part 73 Outer wall part 80 Coil 611 Central core back part 612 Connection core back part 701 Upper insulator piece 702 Lower insulator piece 721 Axial edge 722 Circumferential edge 723,723A Corner part 731 Plane part 732 Curved part 733 Reinforcement part

Claims (16)

A shaft disposed along a central axis extending vertically;
A rotor that rotates about the central axis together with the shaft;
A stator disposed around the rotor;
Have
The stator is
A plurality of core pieces made of a magnetic material and arranged in the circumferential direction;
An insulator attached to each of the plurality of core pieces;
A coil composed of a conductive wire wound around each of the plurality of insulators;
Have
The plurality of core pieces are respectively
A core back extending in the circumferential direction;
Teeth projecting radially inward from the core back;
Have
A plurality of the core backs are connected in a ring shape,
Each of the plurality of insulators is
A teeth insulating portion interposed between the teeth and the coil;
An inner wall located radially inward of the coil and extending substantially perpendicular to the radial direction;
Have
The inner wall portion is
A pair of axial edges located at opposite ends in the axial direction;
A pair of circumferential edges located at opposite ends in the circumferential direction;
Four corners located at the boundary between the axial edge and the circumferential edge;
Have
As viewed from the inside in the radial direction, the corner portion is located in a region closer to the teeth than an imaginary line extending from the axial end edge and the circumferential end edge. The motor according to claim 1,
Seen from the inside in the radial direction,
An axial distance from the upper axial end of the inner wall portion to the lower axial end is A,
A circumferential distance from one circumferential end of the inner wall portion to the other circumferential end is B,
The maximum distance from the center point in the axial direction and the circumferential direction of the teeth to the corner is C,
And when
C ² <(A / 2) ² + (B / 2) ²
A motor that satisfies the relationship. The motor according to claim 1 or 2,
Seen from the inside in the radial direction,
The distance from the axial center point of the teeth and the circumferential center point to the axial edge is shorter than the distance from the center point to the corner,
The distance from the said center point of the said teeth to the said circumferential direction edge is a motor shorter than the distance from the said center point to the said corner | angular part. In the motor according to any one of claims 1 to 3,
When viewed from the inside in the radial direction, the corner portion includes an imaginary line obtained by extending a circumferential end portion of the axial end edge in the circumferential direction, and an axial end portion of the circumferential end edge extending in the axial direction. The motor is located in a region closer to the teeth than the imaginary line. In the motor according to any one of claims 1 to 4,
The said corner | angular part is a motor which is circular arc shape seeing from radial direction inner side. In the motor according to any one of claims 1 to 5,
The stator is a motor having three core pieces. The motor according to any one of claims 1 to 6, wherein
The core back is
A central core back portion extending substantially perpendicular to the teeth;
A pair of connecting core back portions located on both sides in the circumferential direction of the central core back portion;
Have
The connecting core back portion extends from a circumferential end portion of the central core back portion while being bent in a direction approaching the teeth. In the motor according to any one of claims 1 to 7,
The length of the inner wall portion in the circumferential direction is longer than the radial length of the tooth insulating portion. In the motor according to any one of claims 1 to 8,
A resin motor cover for holding the stator;
At least one of the core pieces has a fixing hole on a radially outer side of the teeth,
The motor, wherein the motor cover and the core piece are fixed by a fixing member inserted into the fixing hole. The motor according to claim 9, wherein
A motor in which all the core pieces have the fixing holes. In the motor according to any one of claims 1 to 10,
Each of the plurality of insulators is
The motor further comprising an outer wall portion that is located radially outside of the coil and extends substantially perpendicular to the radial direction. The motor according to claim 11, wherein
The outer wall is
The motor which has a plane part which overlaps with the inner wall part in the diameter direction, and spreads in the direction perpendicular to the teeth and flat. The motor according to claim 11 or claim 12,
The outer wall is
A motor having a reinforcing portion extending in a radial direction. In the motor according to any one of claims 1 to 13,
The plurality of insulators are arranged at intervals in the circumferential direction,
A motor in which a plurality of core back joints are exposed from the insulator. The motor according to any one of claims 1 to 14,
The insulator is
An upper insulator piece covering the core piece from above;
A lower insulator piece that covers the core piece from below;
Have
The motor with which the lower end part of the said upper insulator piece and the upper end part of the said lower insulator piece contact in the contact surface inclined with respect to the axial direction. The motor according to any one of claims 1 to 15,
A centrifugal impeller disposed above the motor and rotating together with the rotor;
A blower casing that houses at least the upper end of the motor and the impeller radially inside;
Having centrifugal blower.

Images