JP2012147615A - Motor and low-speed rotation structure of blower fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor capable of reducing electronic component cost and production cost of electronic component mounting.SOLUTION: A motor 12 and a low-speed rotation structure of a blower fan 1 comprise: an armature 1222 formed of magnetic material; a stator core 41 having a plurality of teeth which protrudes outward in a radial direction from an annular core back; and a coil 44 formed by winding a conductive wire around the stator core 41. The coil 44 is composed of a normal wound coil, in which a conductive wire is wound in a predetermined direction, and a reverse wound coil, in which a conductive wire is wound in a reverse direction of the predetermined direction.

Description

  The present invention relates to an electric motor and a blower fan using the same.

  Conventionally, each specification of high speed rotation or low speed rotation is properly used in consideration of the environment where the blower fan is installed. When cooling an electronic component that generates high heat, the air volume of the blower fan is increased by high-speed rotation to improve cooling efficiency. When the cooling fan is required to have minimum cooling characteristics and low noise, the fan is rotated at a low speed.

In order to increase the speed of the blower fan, there are a method of increasing the diameter of the winding and a method of reducing the number of windings. Since these methods can be handled only by changing the winding, they do not affect the increase in production cost. On the other hand, in order to reduce the speed of the blower fan, there are a method of reducing the winding diameter and a method of increasing the number of windings. However, depending on the motor specifications, even if the above method is used, the speed reduction may not be realized. In this case, by connecting a resistor in series with the conducting wire constituting the winding, the current flowing in the winding can be reduced and low-speed rotation can be realized. Further, low-speed rotation can be realized by PWM (pulse width modulation) control for adjusting on / off of the switching element disclosed in Patent Document 1.
JP 2001-177984 A

  When the above-described method is employed, the number of electronic component mounting points increases, resulting in an increase in component cost and production cost.

  An object of the present invention is to reduce electronic component costs and production costs for mounting electronic components.

  An exemplary motor of the present invention includes a stator portion, a rotor portion that rotates about a central axis, and a bearing mechanism that rotatably supports the rotor portion with respect to the stator portion, the rotor portion being A substantially cylindrical yoke with a lid, and a field magnet attached to the inside of the yoke, and the stator portion is disposed inside the yoke, and generates torque with the field magnet. A plurality of armatures that are generated, and a circuit board that is electrically connected to the armatures, wherein the armatures are made of a magnetic material and project radially outward from an annular core back. And a coil formed by winding a conductive wire around the stator core, and the coil includes a positive winding coil in which the conductive wire is wound in a predetermined direction, and the predetermined coil. Winding in the opposite direction Reverse wound coil, in constructed.

  According to the present invention, the number of electronic component mounting points can be reduced.

FIG. 1 is a cross-sectional view of an axial fan according to an embodiment. FIG. 2 is a plan view of the armature according to the embodiment. FIG. 3 is a schematic diagram showing the winding of the conductive wire. FIG. 4 is a schematic diagram showing the winding of the conductive wire.

  In the present specification, in the direction of the central axis J1, the upper side in the figure is simply called “upper side”, and the lower side in the figure is simply called “lower side”. The expressions “upper” and “lower” do not necessarily coincide with the upper and lower sides with respect to the direction of gravity.

(Embodiment)
FIG. 1 is a cross-sectional view of an axial fan 1 which is a blower fan according to the first embodiment of the present invention. The axial fan 1 includes an electric single-phase motor 12 (hereinafter referred to as “motor 12”), a plurality of blades 11, a housing 13 that surrounds the outer periphery of the motor 12, and a plurality of support ribs 14. The housing 13 is connected to the motor 12 by a support rib 14. The plurality of blades 11 are fixed to the rotor portion 121 of the motor 12, and the plurality of support ribs 14 support the motor 12.

  The housing 13 and the support rib 14 are formed as one member by resin injection molding. The housing 13 and the support rib 14 may be formed as one member by aluminum die casting. In FIG. 1, for convenience of illustration, the schematic shapes of the blade 11 and the support rib 14 are shown on the left and right of the central axis J1.

  The motor 12 includes a rotor portion 121 that is a rotating body, a stator portion 122 that is a fixed body, and a substantially cylindrical bottomed bearing portion 123 that is fixed to the stator portion 122. In the motor 12, the rotor portion 121 is located above the stator portion 122 along the central axis J1.

  The rotor unit 121 includes a substantially cylindrical covered rotor cup 1211, a metal yoke 1212, a substantially cylindrical field magnet 1213, and a shaft 1214.

  The metal yoke 1212 has a substantially cylindrical shape centered on the central axis J1. A substantially cylindrical field magnet 1213 is attached to the inside of the rotor cup 1211 via a yoke 1212. The shaft 1214 protrudes downward from the center of the lid 1212a of the yoke 1212. A plurality of blades 11 protrude radially outward from the outer periphery of the rotor cup 1211.

  The stator portion 122 includes a substantially disc-shaped base portion 1221, an armature 1222, and a substantially annular circuit board 1223. The substantially disk-shaped base portion 1221 has a bearing portion 123 at the center opening. The armature 1222 is attached to the outer surface of the bearing portion 123. The substantially annular circuit board 1223 is disposed below the armature 1222. The base portion 1221 is located on the side opposite to the lid portion 1211a of the rotor cup 1211 of the armature 1222 in the direction of the central axis J1. The armature 1222 is indirectly fixed to the base portion 1221 through the bearing portion 123.

  The armature 1222 includes a stator core 41, an upper insulator 42 and a lower insulator 43, and a coil 44. Stator core 41 is formed by laminating thin silicon steel plates. The upper insulator 42 and the lower insulator 43 cover the upper and lower portions of the stator core 41. The coil 44 is formed by winding a conductive wire 441 from above the upper insulator 42 and the lower insulator 43. The armature 1222 is disposed inside the rotor cup 1211 and faces the field magnet 1213 in the radial direction. The armature 1222 is supplied with an electric current from an external power source (not shown) via the circuit board 1223 to generate a magnetic field, and generates a torque around the central axis J1 with the field magnet 1213. Details of the method for winding the conductive wire 441 will be described later.

  The bearing portion 123 includes a sleeve 1231, a sleeve housing 1232, and a thrust bearing member 1233. The sleeve 1231 has a substantially cylindrical shape centered on the central axis J1. The sleeve housing 1232 covers the outer surface and the lower part of the sleeve 1231 and has a substantially cylindrical shape with a bottom. The thrust bearing member 1233 is disposed on the inner bottom surface of the sleeve housing 1232.

  The shaft 1214 of the rotor portion 121 is inserted into the sleeve 1231, and the lower end of the shaft 1214 comes into contact with the thrust bearing member 1233. The sleeve 1231 is impregnated with lubricating oil, and the lubricating oil is held in the bearing portion 123 by the sleeve housing 1232. The bearing portion 123 of the present invention uses a sleeve, but the present invention is not limited to this. For example, a ball bearing may be used.

  In the motor 12, the bearing mechanism 120 is configured by the sleeve 1231, the sleeve housing 1232, the thrust bearing member 1233, the shaft 1214, and the lubricating oil. In the motor 12, the rotor portion 121 is rotatably supported with respect to the stator portion 122. In the outer rotor type motor 12, the rotor portion 121 rotates around the central axis J <b> 1 around the armature 1222. As a result, the blade 11 protruding radially outward from the rotor portion 121 rotates, and an air flow in the direction of the central axis J1 is generated from the upper side to the lower side in FIG.

  FIG. 2 is a plan view of the armature viewed from above the central axis J1. In FIG. 2, the coil 44 is not shown for convenience of explanation. The armature 1222 includes an annular core back part 411 centering on the central axis J1, a plurality of teeth 412a, 412b, 412c, 412d protruding from the core back part 411 radially outward, and adjacent teeth 412a, 412b. 412c and 412d, and conductive pins 45A, 45B and 45C held by the conductive pin holding portion 431. The conductive wire 441 is electrically connected to the conductive pins 45A, 45B, and 45C, and is electrically connected by soldering to the circuit board 1223 via the conductive pins 45.

  The teeth 412 a, 412 b, 412 c, and 412 d have a teeth body portion 4121 that extends in the radial direction and an umbrella portion 4122 that extends to both sides in the circumferential direction at the radially outer end of the teeth body portion 4121. The upper insulator 42 and the lower insulator 43 cover the upper and lower surfaces and the outer surfaces of the core back portion 411, the upper and lower surfaces and the circumferential side surfaces of the teeth body portion 4121, the upper and lower surfaces of the umbrella portion 4122, and the radially inward surfaces. ing.

  The lower insulator 43 is provided with a conductive pin holding portion 431 that protrudes radially outward at a portion covering the outer surface of the core back portion 411. The conductive pin holding portion 431 has a through hole that penetrates in a direction substantially parallel to the central axis J1. The conductive pin 45 is held by the conductive pin holding portion 431 in a state of passing through the through hole.

  Next, a method for winding the conductive wire 441 will be described in detail. 3 and 4 are schematic views showing the winding of the conductive wire. 3 and 4 are development views of the armature 1222 as viewed from the outside in the radial direction. The arrow shown on the conductive wire 441 in the figure indicates that the conductive wire 441 is wound around the teeth 412a, 412b, 412c, and 412d. Indicates the direction of rotation. First, the normal winding will be described with reference to FIG. The end portion 441a of the conductive wire is entangled with the conduction pin 45A. And it is wound counterclockwise around the first tooth 412a. The portion where the conductive wire 441 is wound is precisely the tooth main body 4121, but this description is omitted in the following description.

  Thereafter, the conductive wire 441 is wound clockwise around the fourth tooth 412d. Next, the conductive wire 441 is wound counterclockwise around the third tooth 412c. Finally, the conductive wire 441 is wound clockwise around the second tooth 412b.

  Next, reverse winding will be described with reference to FIG. The end portion 441b of the conductive wire that is normally wound by the above-described process is entangled with the conduction pin 45C. Here, the conduction pin 45 </ b> C does not need to be electrically connected to the coil 44 and the circuit board 1221. In the present embodiment, the conductive pin 45C uses the same component as the conductive pins 45A and 45B for the purpose of conduction in order to make the components common in manufacturing, but a conductive member is used. There is no need. That is, the conductive pin 45C is intended to temporarily fix the end 441b of the conductive wire. Therefore, regarding the conductive pin 45C, if the end portion 441b of the conductive wire can be temporarily fixed, it is possible to change the shape such as providing a hooking portion on either the upper insulator 42 or the lower insulator 43. The formation position of the latching portion is not limited.

  After the process described above, the conductive wire 441 is wound clockwise around the third tooth 412c. Next, the conductive wire 441 is wound counterclockwise around the fourth tooth 412d. Next, the conductive wire 441 is wound clockwise around the first tooth 412a. Thereafter, the second teeth 412b are wound counterclockwise. Finally, the end portion 441c of the conductive wire is entangled with the conduction pin 45B.

  The conductive wires 441 entangled with the respective conductive pins 45A, 45B, 45C attempt to conduct the conductive pins 45A, 45B, 45C and the conductive wires 441 by soldering the entangled portions. As shown in FIG. 1, the conductive wire 441 is soldered to the respective conduction pins 45A, 45B, 45C on the upper side in the axial direction of the armature 1222. However, the conductive wire 441 may not be electrically connected to the conductive pin 45C. As a result, the conductive wire 441 constituting the forward winding coil and the conductive wire 451 constituting the reverse winding coil are connected in series from the winding start end 441a of the conductive wire connected to the circuit board to the winding end end 441c of the conductive wire. It leads to. Further, current in the same direction flows between the end portion 441a of the conductive wire and the end portion 441c of the conductive wire. The same direction means that the current flowing in the conductive wire 441 is switched by the control circuit, so that the current flowing from the conductive wire winding start end 441a to the conductive wire winding end 441c and the conductive wire winding It includes both of the current flowing from the end 441c to the winding start end 441a of the conductive wire.

  The number of forward windings is greater than the number of reverse windings. By the normal winding, a coil for applying torque in a direction in which the motor 12 is desired to rotate is formed. On the other hand, by performing reverse winding, a coil that generates a magnetic flux opposite to the magnetic flux generated on the outer periphery of the armature 1222 generated by forward winding is formed. That is, the magnetic flux generated by the reverse winding coil cancels a part of the magnetic flux generated by the forward winding coil. Therefore, if the difference in the number of turns increases, the rotation speed of the motor 12 increases. If the difference in the number of turns decreases, the rotation speed of the motor 12 decreases. It is preferable to increase the space factor by reducing the wire diameter of the conductive wire 441 as much as possible. By increasing the space factor, the total number of turns of the reverse winding coil and the normal winding coil can be increased. Thereby, the difference in the number of turns between the reverse winding coil and the normal winding coil can be finely adjusted, so that the rotation speed can be easily adjusted. Here, the space factor is the ratio of the area occupied by the cross section of the winding in the region where the winding can be wound.

  The coil forming process of the armature 1222 according to the present embodiment has the same production man-hour difference as compared with the coil forming process of only the normal winding. That is, there is no increase in production man-hours and parts as compared with the conventional low-speed rotation method. This makes it possible to provide a low-cost low-speed motor. Further, suppressing the increase in electronic components enables the circuit board 1223 to be miniaturized. In general, the circuit board 1223 is formed by cutting out a plurality of circuit boards 1223 from a sheet substrate as a base material. That is, if the circuit board 1223 can be downsized, the number of circuit boards 1223 obtained from one sheet substrate can be increased. Since the area of the sheet substrate after the circuit board 1223 is cut out is smaller than that of the circuit board before the circuit board 1223 is downsized, the number of substrates obtained is high. Thereby, further cost reduction is possible.

  The circuit board 1223 is configured with a control circuit that controls the rotation of the motor 12. In recent years, motors are required to have higher functions, and complicated rotation control and control mechanisms outside the motor may be incorporated on the circuit board 1223. In this case, many electronic components are mounted on the circuit board 1223. When it is attempted to reduce the rotation speed by the conventional method, there is a possibility that a part for mounting the electronic component for reducing the speed cannot be secured on the circuit board. However, by adopting this embodiment, it is possible to realize a low rotation without mounting electronic components. In addition, it is possible to further reduce the rotation speed by adding electronic components to this embodiment.

  The present invention is not limited to the above embodiment, and may be variously modified. For example, in the above-described embodiment, the armature 1222 for single-phase bipolar driving has been described. However, in the two-phase or three-phase driving system, if the coil 44 is configured by forward winding and reverse winding, driving is possible. The method is not limited.

  In the above embodiment, the present invention is limited to the axial fan, but may be applied to a centrifugal fan or a motor other than the fan.

  The conductive pin 45 is not limited to be provided between the adjacent teeth 412a, 412b, 412c, and 412d, and may be provided at a portion that covers the lower surface of the teeth 412a, 412b, 412c, and 412d of the lower insulator 43. In this case, the conductive wire 441 is entangled with the conductive pin 45 on the lower side in the axial direction of the armature 1222. In the above embodiment, the conductive pin 45 is used to connect the circuit board 1223 and the conductive wire 441. However, the conductive wire 441 may be directly connected to the circuit board 1223.

  The present invention can be used for motors for various purposes.

1 axial fan 11 blade 12 motor 41 stator core 42 upper insulator 43 lower insulator 44 coil 45, 45A, 45B, 45C conducting pin 120 bearing mechanism 121 rotor portion 122 stator portion 412a, 412b, 412c, 412d teeth 441, 441a, 441b, 441c Conductive wire 451 Conductive wire 1211 Rotor cup 1213 Field magnet 1221 Base portion 1222 Armature 1223 Circuit board J1 Central axis

Claims (11)

A stator portion;
A rotor that rotates about a central axis;
A bearing mechanism for rotatably supporting the rotor portion with respect to the stator portion;
With
The rotor part is
A substantially cylindrical yoke with a lid;
A field magnet attached to the inside of the yoke;
With
The stator portion is
An armature disposed inside the yoke and generating torque with the field magnet;
A circuit board electrically connected to the armature;
With
The armature is
A stator core made of a magnetic material and having a plurality of teeth protruding radially outward from an annular core back;
A coil formed by winding a conductive wire around the stator core;
With
The coil is a motor constituted by a forward winding coil in which the conductive wire is wound in a predetermined direction and a reverse winding coil wound in a direction opposite to the predetermined direction. The motor according to claim 1,
An insulator covering the upper and lower portions of the stator core;
A conductive wire is wound from above the insulator. The motor according to claim 1 or 2,
The armature has a latching portion;
The conductive wire drawn out from the forward winding coil is hooked on the hooking portion, and the reverse winding coil is wound. The motor according to claim 3, wherein
The hook portion is a conductive pin held by the insulator. The motor according to claim 3, wherein the latching portion is a resin portion formed integrally with the insulator. The motor according to any one of claims 2 to 5,
The insulator includes an upper insulator and a lower insulator. The motor according to any one of claims 1 to 6,
The magnetic flux generated by the forward winding coil and the magnetic flux generated by the reverse winding coil are in opposite directions. The motor according to any one of claims 1 to 7,
The conductive wire constituting the forward winding coil and the conductive wire constituting the reverse winding coil are connected in series from the winding start end of the conductive wire connected to the circuit board to the winding end end of the conductive wire. ing. The motor according to claim 8, wherein
A current in the same direction flows from the winding end of the conductive wire to the winding end of the conductive wire. The motor according to any one of claims 1 to 9,
The number of turns of the normal winding coil is larger than the number of turns of the reverse winding coil. A motor according to any one of claims 1 to 10,
A plurality of blades that project radially outward from the rotor cup of the motor and generate air flow by rotating about the central axis;
A blower fan comprising:

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