JP2015202032A - motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To resolve a problem that, when a circuit board is fixed by an engaging claw, a load resistance in an axial direction is low, which causes vibration of the circuit board.SOLUTION: A motor 10 comprises: a shaft 11; a rotor 12 that rotates together with the shaft; a stator 13 located radially outside the rotor; an upper bracket 14 arranged on an upper side of the stator; a lower bracket 15 arranged at a lower side of the stator, and that holds a bearing member 17; and a circuit board 16. The stator has: a stator core 20 that includes a core back and a plurality of magnetic pole teeth; a coil 22; and an insulation member 21 for insulating the stator core and the coil from each other. The upper bracket has a fixed part 23 contacted with an outer peripheral surface of the stator core and that extends radially inward. The fixed part and the circuit board are contacted with each other in an axial direction, and the insulation member and the circuit board are contacted with each other in the axial direction. Due to this configuration, the circuit board is fixed strongly by a bracket and the insulation member. In addition, a large circuit board can be also fixed strongly, and a range of design is increased.

Description

  The present invention relates to a motor, and more particularly to an inner rotor type motor.

The brushless motor disclosed in Japanese Patent Application Laid-Open No. 2008-54390 includes a rotor and a stator positioned on the outer periphery of the rotor. The stator includes a stator core and a coil formed of an insulating member and a conductive wire wound around the stator core via the insulating member. The central shaft passes through the center of the rotor and is rotatably supported by a bearing. The circuit board is attached to the insulating member. Specifically, three engaging claws are provided at three positions around the insulating member, the engaging claws have an engaging arm portion and a claw portion, and a guide surface is provided on the outer surface of the claw portion. An engagement surface is provided on the inner surface of the nail. In FIG. 1, one of the three engaging claws is shown. When the circuit board is fixed, the circuit board is pushed in by pushing the circuit board along the direction of the arrow so as to contact the guide surface and deforming the engaging claw. The broken line in FIG. 1 shows how the engaging claw is deformed. The engagement surface comes into contact with one side surface of the circuit board by the elastic force of the engagement arm portion. An anti-rotation protrusion is provided on the inner peripheral surface of the engagement arm, and the anti-rotation protrusion engages with a corresponding recess of the circuit board to prevent the circuit board from rotating. The insulating member is further provided with a step portion (not shown), and this step portion engages with the other surface of the circuit board. The circuit board is fixed by the engaging claw and the stepped portion. The engaging surface may be an inclined surface. With this configuration, the circuit board can be firmly fixed even if the thickness of the circuit board does not match.
JP 2008-54390 A

  However, when the circuit board is fixed by the engaging claws, the load resistance in the axial direction is small, which causes vibration of the circuit board.

  An object of the present invention is to provide a motor capable of reducing vibration by firmly fixing a circuit board.

  An exemplary first invention of the present application includes: a shaft rotatably supported by a bearing member; a rotor that rotates together with the shaft; a stator that is positioned radially outward from the rotor; An upper bracket disposed on the upper side, a lower bracket disposed on the lower side of the stator and holding a bearing member, and a circuit board are provided, and the rotor is directly or indirectly fixed to the shaft. The stator further includes a rotor magnet, and the stator is configured to insulate the stator core and the coil from a core back, a stator core including a plurality of magnetic pole teeth, a coil formed of a conductive wire wound around the magnetic pole teeth. The upper bracket is in contact with the outer peripheral surface of the stator core, and the upper bracket has a fixing portion extending radially inward, and the fixing portion and the circuit Plate is in contact in the axial direction, the circuit board and the insulating member is a motor in contact in the axial direction.

  According to the exemplary first invention of the present application, the vibration of the circuit board can be reduced. In addition, the range of design becomes wider.

FIG. 1 is a partial view of an insulating member and a circuit board of a motor in the prior art. FIG. 2 is a cross-sectional view of the motor according to the first embodiment of the present invention. FIG. 3 is a plan view of the motor according to the first embodiment of the present invention. FIG. 4 is a plan view of the fixing portion of the upper bracket of the motor according to the first embodiment of the present invention. FIG. 5 is a plan view of the fixing portion of the upper bracket of the motor according to the modification of the present invention. FIG. 6 is a plan view of an upper bracket of a motor according to a modification of the present invention.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In this application, the direction parallel to the central axis of the motor is the “axial direction”, the direction orthogonal to the central axis of the motor is the “radial direction”, and the direction along the arc centered on the central axis of the motor is the “circumferential direction”. , Respectively. In the present application, the shape and positional relationship of each part will be described with the axial direction being the vertical direction and the circuit board side being “up” with respect to the stator. However, this is defined as upper and lower for convenience of explanation, and does not limit the direction when the motor according to the present invention is used. In the present application, the drawings are not shown to a specific scale.

<First Embodiment>
FIG. 2 is a cross-sectional view of the motor 10 according to the first embodiment of the present invention. The motor 10 includes a shaft 11, a rotor 12, a stator 13, an upper bracket 14, a lower bracket 15, and a circuit board 16.

  The shaft 11 is disposed along a central axis O-O ′ extending vertically and is rotatably supported by the bearing member 17. The bearing member 17 may be a ball bearing. The rotor 12 rotates together with the shaft 11. The rotor 12 has a rotor magnet 18 that is indirectly fixed to the shaft 11. For example, as shown in FIG. 2, the rotor magnet 18 is fixed to the shaft 11 by a rotor holder 19. However, the rotor magnet 18 does not necessarily need to be indirectly fixed to the shaft 11, and the rotor magnet 18 may be directly fixed to the shaft 11 in other embodiments.

  The stator 13 is located on the radially outer side of the rotor 12 and includes a stator core 20, an insulating member 21, and a coil 22. The stator core 20 includes a core back and a plurality of magnetic pole teeth. The coil 22 is composed of a conductive wire wound around magnetic pole teeth.

  The insulating member 21 insulates the stator core 21 and the coil 22 from each other. The insulating member 21 has a pinned pin (not shown), whereby the conductive wire is easily connected to the circuit board 16. For example, the conductive wire is connected to the circuit board 16 by soldering. Preferably, the number of thorn pins is at least twice the number of phases of current flowing through the coil 22. For example, it is 2 times, 3 times, 4 times or an integer multiple greater than 4. With this configuration, the lead wires through which the respective phase currents flow are connected to different lash pins, so that the motor 10 can be assembled more easily by increasing the number of lash pins. In particular, as the motor 10 is reduced in size, the motor can be easily assembled by connecting the lead wires through which the phase currents flow to different tangled pins.

  The lower bracket 15 is disposed below the stator 13 and holds the bearing member 17. The lower bracket 15 includes an inner peripheral wall, an outer peripheral wall, and a bottom wall for connecting both. The inner peripheral wall holds the bearing member 17, and a part of the stator 13 is accommodated in an annular space formed by the inner peripheral wall, the outer peripheral wall, and the bottom wall.

  The upper bracket 14 is located on the upper side of the stator 13 and is in contact with the outer peripheral surface of the stator core 20. The upper bracket 14 has a fixing portion 23 that extends radially inward. When the motor is assembled, the lower surface in the axial direction of the circuit board 16 is brought into contact with the insulating member 21 in the axial direction, and the upper surface in the axial direction of the circuit board 16 is brought into contact with the fixing portion 23 of the upper bracket 14 in the axial direction. That is, the circuit board 16 is firmly fixed between the insulating member 21 and the fixing portion 23 of the upper bracket 14. With such a structure, the vibration of the circuit board 16 in the operating state of the motor 10 can be reduced by fixing the circuit board 16 in the vertical direction. Note that the circuit board 16 having a large size can also be firmly fixed, so that the motor 10 can be multifunctional and the design range can be widened.

  As shown in FIG. 2, the outer peripheral surface of the stator core 20 does not need to be completely sealed by the upper bracket 14 and the lower bracket 15, and at least a part of the outer peripheral surface of the stator core 20 is exposed. With such a structure, the thickness of the stator core 20 in the axial direction can be adjusted according to the demand for motor output.

  As shown in FIG. 2, at least a part of the circuit board 16 extends outward in the radial direction of the upper bracket 14. In this way, the number of electronic components 25 that can be mounted on the circuit board 16 can be increased, the design range can be widened, and the motor 10 can be multi-functionalized. As shown in FIG. 2, the magnetic position detection element 24 is disposed on the lower surface in the axial direction of the circuit board 16. With this configuration, the magnetic position detection element 24 is disposed in the vicinity of the rotor magnet 18, and the rotational position of the rotor 12 can be detected with high accuracy. Here, as the magnetic position detection element 24, for example, a Hall IC is used.

  In another embodiment, the upper bracket 14 is formed by pressing. For example, the upper bracket 14 is formed by pressing a metal plate (such as a steel plate). With this configuration, the upper bracket 14 can be formed at a low cost. When the upper bracket 14 is formed of a metal plate, the circuit board 16 is grounded via the upper bracket 14 by forming a ground pattern in the circuit board 16 at a location in contact with the upper bracket 14. be able to.

  FIG. 3 is a plan view of the motor 10 of the first embodiment shown in FIG. 4 is a plan view of the fixing portion 23 of the upper bracket 14 of the motor 10 of the first embodiment shown in FIG.

  As shown in FIG. 4, the upper bracket 14 includes one fixing portion 23, and the fixing portion 23 extends radially inward along a part of the circumference of the upper bracket 14. Part of the direction is open. Here, the circumferential length of the fixing portion 23 is 90 ° to 270 ° with respect to the central axis O-O ′, and preferably has a central angle of 150 ° to 240 °. More preferably, the central angle is 180 °. When viewed from the axial direction, the shape of the upper bracket 14 is substantially arc-shaped or substantially C-shaped. In this way, the load capacity in the axial direction of the upper bracket 14 can be increased, and the electronic component 25 can be disposed on the radially outer portion of the circuit board 16, thereby widening the design range of the circuit board 16. In addition, the multifunction of the motor 10 can be realized.

  As shown in FIG. 3, the electronic component 25 is mounted on the upper or lower surface of the circuit board 16 in the axial direction. Here, as an example of the electronic component 25, a resistor, a capacitor, a coil, or the like is often mounted. In FIG. 3, the electronic component 25 is mounted on a portion of the circuit board 16 that is radially outward from the upper bracket 14. In this way, the design range of the circuit board 16 is widened, and the multifunction of the motor 10 can be realized. At the same time, even when it is necessary to mount the electronic component 25 having a large axial dimension on the circuit board 16, the electronic component 25 can be mounted on the upper surface in the axial direction of the circuit board 16. That is, even if the electronic component 25 having a large axial dimension is mounted on the upper surface in the axial direction of the circuit board 16, interference between the electronic component 25 and the stator 13 can be prevented, and the width of the motor design is widened.

  5 and 6 are plan views of modifications of the fixing portion 23 of the upper bracket 14 of the motor 10 according to the present invention.

<Modification 1>
In the first modification shown in FIG. 5, the upper bracket 114 has two fixing portions 123 that are arranged at intervals in the circumferential direction. One of the two fixing parts 123 extends along a part of the circumference of the upper bracket 114, and the two fixing parts 123 are arranged so as to face each other with a gap in the circumferential direction. 123 is connected by a connecting portion 126 extending in the radial direction. Here, the two fixing parts 123 are arranged in the range of 15 ° to 60 ° in the circumferential direction, and preferably arranged in the range of 20 ° to 40 °. In the most preferred form, the two fixing parts 123 are arranged in a range of 30 °. When viewed in the axial direction, the upper bracket 114 is H-shaped. With this configuration, the circuit board 16 can extend outward in the radial direction from the upper bracket 114, the electronic component 25 can be easily arranged, the design width of the circuit board 16 is widened, and the motor 10 can be multi-functionalized. .

<Modification 2>
As shown in FIG. 6, the upper bracket 214 has three fixing portions 223 that are spaced apart in the circumferential direction. Any of the three fixing portions 223 extends along the circumferential direction of the upper bracket 214, is arranged at an interval of approximately 90 ° in the circumferential direction, and is connected by a connecting portion 226 extending in the radial direction. Here, any one of the three fixing portions 223 is arranged in the range of 15 ° to 60 °, preferably in the range of 20 ° to 40 °, with the central axis as the center in the circumferential direction. More preferably, the central angle is 30 °. In other embodiments, the number and arrangement of the fixing portions 223 may be different. For example, the number of the fixing portions 223 is four or more, and the circumferential interval at which the fixing portions 223 are arranged is uneven. But you can.

  The present invention further has the following effects.

  In the first embodiment, the upper bracket 14 is molded by pressing. With this configuration, the cost of the motor 10 can be reduced, and the circuit board 16 can be grounded by the upper bracket 14 when the upper bracket 14 is molded from a metal plate.

  In the first embodiment, at least a part of the circuit board 16 extends outward in the radial direction of the upper bracket 14. With such a structure, many electronic components 25 can be mounted on the circuit board 16, the design width can be widened, and the multifunction of the motor 10 can be realized.

  In the first embodiment, the insulating member 21 has a tangled pin. With such a structure, the conducting wire can be easily connected to the circuit board 16.

  In the first embodiment, the number of tangled pins is twice or more the number of phases of the current flowing through the coil 22. With such a structure, even a small motor 10 can be easily assembled.

  In the first embodiment, at least a part of the radially outer side of the stator core 20 is exposed. With this configuration, the overall axial thickness of the stator core 20 can be adjusted in accordance with a request for motor output.

  In the first embodiment, the electronic component 25 is mounted on the upper or lower surface in the axial direction of the circuit board 16. With this configuration, the design range of the circuit board 16 is widened, and the multifunction of the motor 10 can be realized.

  In the first embodiment, the upper bracket 14 has an arc shape when viewed in the axial direction. With this configuration, the load resistance in the axial direction of the upper bracket 14 can be increased, the electronic component 25 is disposed on the radially outer portion of the circuit board 16, the design width of the circuit board 16 is widened, and the number of motors 10 can be increased. Functionalization can also be realized.

  In the first modification, when viewed in the axial direction, the fixing portion 123 of the upper bracket 114 is substantially H-shaped. With this configuration, electronic components are arranged on the radially outer portion of the circuit board 16, the design width of the circuit board 16 is widened, and the motor 10 can be multi-functionalized.

  In the first embodiment, the magnetic position detection element 24 is mounted on the lower surface in the axial direction of the circuit board 16. With this configuration, the circuit board 16 extends radially outward, and the electronic component 25 can be more easily mounted, the design range of the circuit board 16 is widened, and the multifunction of the motor 10 can be realized.

  In the first embodiment, the magnetic position detection element 24 is mounted on the lower surface in the axial direction of the circuit board 16. With this configuration, the magnetic position detection element 24 can be moved closer to the rotor 12, and the rotational position of the rotor 12 can be detected with high accuracy.

  The motor of the present invention can be used for OA equipment such as printers and copiers, transportation equipment such as automobiles, various home appliances, medical equipment, disk drives and the like, which generate various driving forces. .

  In addition, about the detailed shape of a motor, you may differ from each drawing of this application. Moreover, you may combine suitably each element which appeared in said embodiment and modification in the range which does not produce inconsistency.

  The present invention can be used for a motor.

OO ′ center axis 1, 21 insulating member 2 engaging claw 2a engaging arm portion 2b claw portion 2c guide surface 2d engaging surface 2e non-rotating protrusion 3,16 circuit board 3a recess 10 motor 11 shaft 12 rotor 13 fixed Child 14, 114, 214 Upper bracket 15 Lower bracket 17 Bearing member 18 Rotor magnet 19 Rotor holder 20 Stator core 22 Coil 23, 123, 223 Fixed portion 24 Magnetic position detection element
25 Electronic parts 126,226 Connection part

Claims (10)

A shaft rotatably supported by a bearing member;
A rotor that rotates with the shaft;
A stator located radially outside the rotor,
An upper bracket disposed above the stator;
A lower bracket disposed under the stator and holding a bearing member;
A circuit board disposed above the stator; and
With
The rotor further includes a rotor magnet fixed to the shaft directly or indirectly,
The stator is
A core back and a stator core including a plurality of magnetic pole teeth;
A coil composed of a conductive wire wound around the magnetic pole teeth;
An insulating member for insulating the stator core and the coil;
Have
The upper bracket is in contact with the outer peripheral surface of the stator core;
The upper bracket has a fixing portion extending radially inward,
The fixed portion and the circuit board are in contact in the axial direction,
The motor, wherein the insulating member and the circuit board are in contact in the axial direction.   The motor according to claim 1, wherein the upper bracket is molded with a metal member by a press.   The motor according to claim 1, wherein at least a part of the circuit board extends radially outward from the upper bracket.   The motor according to any one of claims 1 to 3, wherein the insulating member has a pinned pin.   5. The motor according to claim 4, wherein the number of the tangled pins is at least twice the number of phases of the current flowing through the coil.   The motor according to any one of claims 1 to 5, wherein at least a part of a radial outer side of the stator core is exposed.   The motor according to claim 1, wherein an electronic component is mounted on an upper surface or a lower surface in the axial direction of the circuit board.   The motor according to any one of claims 1 to 7, wherein a shape of the fixing portion of the upper bracket is a substantially arc shape when viewed from the axial direction.   The motor according to any one of claims 1 to 8, wherein a shape of the fixing portion of the upper bracket is substantially H-shaped when viewed from the upper side in the axial direction.   The motor according to claim 1, wherein a magnetic position detection element is mounted on a lower surface in the axial direction of the circuit board.

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