JP4702523B2 - DC motor - Google Patents

Description

  The present invention relates to a single-pole DC motor that does not require a brush / commutator (mechanical inverter) and does not require a semiconductor inverter. More specifically, the present invention uses a permanent magnet for the rotor field and is provided on both sides of the rotor. The present invention relates to an axial gap type DC motor in which an armature stator is arranged.

  A direct current motor is used in many fields as a small motor, and, as a general configuration, for example, a coil is disposed so as to face a disk in which permanent magnets are disposed in the rotation direction. The permanent magnet is arranged so that the magnetic field direction is perpendicular to each disk, and the coil is provided so that the current direction is perpendicular to the magnetic field. Then, according to Fleming's left-hand rule, a force acts on the coil in a direction perpendicular to the direction of the magnetic field and the direction of the current.

  Therefore, when the disks having the permanent magnets are fixed to the case so as to face each other, a rotational force is generated in the circumferential direction in the coil therebetween. As an example of rotating the coil side, there is one used for a rotary actuator (for example, see Patent Document 1).

  In the invention of Patent Document 1, the stator side magnetized in the rotation axis direction is fixed to the case so as to face each other, and a rotor is disposed between the stators. A hollow bobbin with windings is integrated with the rotating shaft of the rotor, and an intermediate yoke is accommodated in the hollow. An actuator is provided with a feature in the shape of the intermediate yoke.

  By the way, when the coil is arranged in the circumferential direction and fixed to the case, the force acting on the coil acts on the permanent magnet of the disk (acts as a reaction), and the disk rotates, for example, a brushless DC motor. Can be used as As an example, Patent Document 2 proposes a single-pole DC motor in which a coil side is fixed to a case and a disk having a permanent magnet is rotatable.

  In the invention of Patent Document 2, a magnet magnetized with a single pole in the motor axial direction is fixed to the rotor surface, and the coil portion is arranged so that the magnetic flux generated by this magnet is linked to the coil portion of the stator. Further, a magnetic circuit between the magnet and the stator is formed such that the magnetic flux returns to the rotor side via the stator core and the outer ring yoke.

According to this, when a current is passed through the coil, a force acts on the coil portion in the circumferential direction, and this force acts on the rotor to become a rotational force. In the invention of Patent Document 2, a coil is wound around a core from which the coil portion is separated so that it can be disposed on the stator circumference, and motor winding and assembly are facilitated.
JP-A-60-187252 Japanese Utility Model Publication No. 62-81476

  The problem to be solved by the present invention is that an air gap (air gap) between the rotor and the stator depends on the winding of the stator, so that an optimum air gap for the motor cannot be obtained.

  That is, in the actuator of Patent Document 1, the winding is applied to the hollow bobbin. However, if the number of turns of the coil is increased, the air gap becomes wide and inappropriate, and if the air gap is prioritized, the number of turns of the coil is increased. Is limited. Even in the DC motor of Patent Document 2, the same can be said for Patent Document 1. Moreover, in patent document 2, since the main magnetic flux by a magnet is linked only with a coil part, the resistance of a magnetic circuit is large and is not preferable in terms of efficiency.

In order to solve the above-mentioned problems, an invention according to claim 1 is directed to an axial gap type DC motor in which a rotor as a field magnet and a stator as an armature are opposed to each other. rotor and without by disposing becomes field, the rotor of each so as to face the both sides in the rotation axis direction by arranging the armature two stators and without, field of the rotor, whereas Permanent magnets having different polarities on the stator side and the other stator side are arranged in the circumferential direction to form a monopolar magnetic field, and the armatures of the two stators sandwich the permanent magnet, A plurality of yokes formed by laminating electromagnetic steel plates in the motor radial direction and having a trapezoidal shape or a sector shape are arranged at equal intervals in the circumferential direction, and the yoke has a rotor-side surface facing the permanent magnet. and each inner side surface of the counter-rotor side located on the opposite side Forming a groove over Luo outer peripheral side, to form a tooth on both sides of the groove by performing a toroidal winding in each of the grooves, of the yoke, in the axial direction by sandwiching the permanent magnet The teeth formed on the opposite rotor surface of the opposing yoke are connected by a back yoke so that the field magnetic flux is closed, and the current is applied to the windings applied to the yokes of the two stators in the opposite direction. flow, and the direction of the current flowing through the windings facing the rotor is characterized in that to generate the same direction of the torque to the field of the rotor as the direction of the same at right angles to the magnetic field by the permanent magnet.

  The invention according to claim 2 is characterized in that, in the above-mentioned claim 1, the back yoke that connects the two teeth on the counter-rotor side of the opposing yoke crosses each other and the teeth at different positions are connected. Yes.

According to a third aspect of the present invention, in the first aspect, the two teeth on the counter-rotor side of each yoke on the one stator side and the two teeth on the counter-rotor side of each yoke on the other stator side are provided. Two teeth are connected to each other by being shifted by one back yoke in the circumferential direction .

  In the DC motor of the present invention, the stator (stator) winding portion acting on the rotor (rotor) field is placed in the groove of the stator yoke, so that the rotor (permanent magnet) and the stator ( The air gap between the teeth can be optimized in terms of motor characteristics, and rotation noise can be suppressed to improve low noise and vibration, and radio noise can be suppressed.

  In addition, the DC motor according to the present invention can be used as an inverterless single-pole DC motor, has a long life due to the brushless and high reliability, and can be further reduced in cost because it is inverterless.

  The direct current motor of the present invention includes a rotor having permanent magnets with magnetic poles in the direction of the rotation axis, and two stators arranged on both sides of the rotor so as to face the permanent magnets with windings applied to the yokes. However, a groove is formed at least on the rotor surface side of the yoke, and a part of each winding is accommodated in the groove, and the air gap between the rotor and the stator is It is possible to determine the optimum one, and it is an inverterless single pole motor.

  FIG. 1 is a schematic sectional side view showing a single-pole DC motor of the present invention. In this axial gap type DC motor, a disk-like rotor (rotor) 2 having a permanent magnet 1 disposed on the outer peripheral side is fixed to a rotating shaft 3, and armatures (windings) are respectively provided on both sides of the rotor 3. The stator (stator) 6 and 7 which has arrange | positioned 4 and 5 is arrange | positioned.

  For the rotor 2 as a field magnet, the permanent magnet 1 on the air gap surface between the stators 6 and 7 has the same magnetic pole facing one stator (for example, S pole) and the magnetic pole facing the other stator. Are the same (for example, N pole) and a monopolar magnetic field is formed. Note that a plurality of the permanent magnets 1 may be arranged in the circumferential direction according to the arrangement of the windings 4 and 5. The rotor 2 is fixed to a rotating shaft 3, and the rotating shaft 3 is rotatably supported by a case 10 of the main body via bearing portions 8 and 9.

  As shown in FIG. 2, the stators 6 and 7 as armature cores are arranged so as to face each other by 2n windings 4 and 5 at equal intervals in the circumferential direction (n: a positive number of 2 or more). However, electromagnetic steel plates are laminated in a direction perpendicular to the rotary shaft 3, and a predetermined number of trapezoidal or sectoral yokes 6a and 7a are arranged at equal intervals in the circumferential direction (for example, 2n (n = 6)). Are arranged in a ring shape), and windings (toroidal windings) 4 and 5 are applied to these yokes 6a and 7a.

  In this case, for each yoke 6a, two yokes 6a adjacent to each other in the circumferential direction are connected to each other at the central portion thereof by a yoke in the same circumferential direction to form a unit core, and a winding 4 is applied to the yoke in a toroidal shape. The armature winding unit (stator) is formed and assembled into a ring shape by resin molding or the like. The yokes 7 a are similarly assembled in a ring shape, but the current flows in the direction opposite to the winding 4 in the toroidal winding 5.

  When each yoke 6a, 7a has a trapezoidal shape, its upper side faces the motor center, its bottom side faces the motor outer peripheral side, and when each yoke 6a, 7a has a fan shape, its inner peripheral surface faces the motor center, The outer peripheral surface is preferably directed toward the motor outer peripheral side.

  Further, both surfaces of the yokes 6a and 7a in the rotation axis direction are teeth (teeth) A, and among these teeth A, a recess groove B extending from the outer periphery to the inner periphery rotates at the central portion of the tooth A on the rotor 2 side. The grooves B are formed to the center, and the grooves B have a predetermined depth so that the partial windings facing the rotor 2 of the windings 4 and 5 are accommodated. In addition, the groove B is formed on the opposite side of the other tooth A to accommodate the windings 4 and 5, and two teeth A are formed on both sides of the groove B on both sides of each of the yokes 6 a and 7 a.

  A back yoke 11 having a U-shaped cross section is provided on the outer peripheral side of the stators 6 and 7 arranged so as to sandwich the rotor 2 so as to cover the outer peripheral side, and the magnetic flux generated by the permanent magnet 1 is one stator yoke, It flows in a closed circuit through the back yoke 11 and the other stator yoke.

  As shown in FIG. 3, the back yoke 11 has two main back yokes 11aa and 11ab, and the yoke 6a The auxiliary back yokes 11ba and 11bb are connected to the tooth A surface of 7a and connected to the main back yokes 11aa and 11ab, respectively, and twelve of them are arranged on the outer periphery of the stators 6 and 7.

  For example, the sub-back yokes 11ba and 11bb are formed by laminating rectangular electromagnetic steel plates, and are aligned with the teeth A of the stators 6 and 7 and are made longer on the outer peripheral side of the stators 6 and 7 by the thickness of the main back yokes 11aa and 11ab. The main back yokes 11aa and 11ab are composed of a linear portion matching the tooth A width of each yoke 6a and 7a and a linear portion intersecting in a region corresponding to the rotor 2, and similar to the sub back yokes 11ba and 11bb. Magnetic steel sheets may be laminated. In this way, the back yoke 11 has a U-shaped cross section and covers the outer peripheral side of the stators 6 and 7.

  The above crossing means that one of the main back yokes is on the other back yoke, that is, the main back yoke 11ab is bent stepwise at the crossing portion, and the main back yoke 11aa passes through the bent portion. Like that.

  The reason for intersecting the main back yokes 11aa and 11ab is that the currents of the windings 4 and 5 of the two stators 6 and 7 are in opposite directions, so that the opposite rotor side of the two stator yokes is simply connected by the back yoke. This is because the magnetic fluxes generated by the armatures of the two stators 6 and 7 cancel each other to reduce the torque.

The operation of the DC motor configured as described above will be described with reference to the partial sectional view of FIG. First, the flow as the magnet flux of the rotor 2 is shown in broken line arrows in the figure, i.e. the stator 6 side of the rotor 2 is an S pole, the stator 7 side of the rotor 2 is an N pole, also of the stator 6 and 7 It is assumed that the windings 4 and 5 flow in opposite directions on the paper surface as indicated by solid arrows in FIG.

  The magnetic flux generated by the permanent magnet 1 of the rotor 2 reaches the rotor 2 through the yoke 7a of the stator 7, the sub-back yoke 11b, the main back yoke 11a, the sub-back yoke 11a, and the yoke 6a of the stator 6, and forms an electromagnetic circuit. . At this time, with respect to the winding 4, the winding portion facing the rotor 2 is positioned perpendicular to the direction of the magnetic field in the magnetic field of the permanent magnet 1. The magnetic force works directly above the paper.

  Similarly, with respect to the winding 5, a magnetic force directly above the paper surface acts on the winding portion facing the rotor 2. In this case, a force of F (∝φ · I) is generated between the magnetic flux φ by the permanent magnet 1 and the current I of the armature winding. Since the stators 6 and 7 are fixed to the case 10 of the main body, the opposite force (reaction) to the force in the same direction acts on the rotor 2, and the opposite force acts on the rotor 2. This torque is generated and the rotor 2 rotates.

  Since the winding portions of the stators 6 and 7 are respectively housed in the grooves B of the yokes 6a and 7a, the surfaces other than the grooves B of the yokes 6a and 7a become the teeth A of the stators 6 and 7, and These teeth A can reduce the resistance of the magnetic circuit of the magnetic flux generated by the permanent magnet 1. Therefore, the air gap between the rotor 2 and each of the stators 6 and 7 can be set to an optimum distance for the motor characteristics and the like without being influenced by the number of turns of the windings 4 and 5, and the efficiency. It is also preferable from the viewpoint.

  As described above, the stators 6 and 7 are fixed to the case 10 via the back yoke 11, the rotor 2 is rotatably supported on the case 10 via the bearing portions 8 and 9, and the bearing portions 8 and 9 are supported. Is preferably held in the case 10.

  FIG. 5 is a schematic plan view showing a modification of the back yoke 11 shown in the above embodiment. In the figure, the same parts as those in FIG.

  In this modified embodiment, of the two main back yokes, the same effect is obtained as when the back yokes connecting the teeth A on the side opposite to the rotor of the yokes 6a, 7a of the stators 6, 7 are exhibited. One main back yoke 20ab is obliquely connected to the sub back yoke 11ba of the yoke 7a facing the adjacent yoke 6a. The main back yoke 20aa has the same connection shape as the main back yoke 11aa of the above embodiment.

  The back yoke 20 is formed by providing twelve main back yokes 20aa and 20ab corresponding to the yokes 6 and 7, respectively. Since the two main back yokes 20aa and 20ab do not cross each other and are all arranged obliquely, this is a preferable aspect from the viewpoint of ease of manufacturing.

  By passing a direct current through the two armature windings 4 and 5, a unidirectional torque is generated in the field rotor 2 by the permanent magnet 1, that is, an inverterless single-pole DC motor (for example, one output shaft) A brushless DC motor) can be realized. As for the air gap, the air gap length is determined based on the thickness of the permanent magnet 2 when set at a predetermined interval, but can be determined to an optimum value in accordance with the motor characteristics.

  According to the present invention, a DC motor can be used as a single-output inverter-less single-pole DC motor, and can be used not only for a fan motor of an air conditioner but also for various devices such as other heating devices and air purifiers. It is.

1 is a schematic side sectional view showing a DC motor of the present invention. The schematic front view explaining the structure of the stator of the DC motor shown in FIG. FIG. 2 is a schematic plan view for explaining a configuration of a stator of the DC motor shown in FIG. 1. FIG. 2 is a schematic partial side sectional view for explaining the operation of the DC motor shown in FIG. 1. The schematic plan view which shows the modification of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet 2 Rotor 3 Rotating shaft 4, 5 Winding 6, 7 Stator 5a, 6a Yoke 8, 9 Bearing part 11, 20 Back yoke 11aa, 11ab, 20aa, 20ab Main back yoke 11ba, 11bb Sub back yoke A Teeth B Groove

Claims (3)

In an axial gap type DC motor in which a rotor as a field and a stator as an armature are opposed to each other,
Arranged in the center of the motor is a permanent magnet, and a rotor, and armatures are arranged so as to face both side surfaces of the rotor in the rotation axis direction, thereby providing two stators.
The rotor field is formed by arranging permanent magnets having different polarities on one stator side and the other stator side in the circumferential direction to form a single-pole magnetic field,
The armatures of the two stators are configured by arranging a plurality of yokes formed in a trapezoidal shape or a sector shape by laminating electromagnetic steel plates in the radial direction of the motor with the permanent magnets sandwiched therebetween, and arranged at equal intervals in the circumferential direction. , to the yoke, said a groove over the outer peripheral side surface of the counter-rotor side located on the surface and the opposite side thereof opposite the rotor side to the permanent magnet from the respective peripheral side, each groove Toroidal winding is applied to form teeth on both sides of the groove ,
Of the yoke, the teeth formed on the surface opposite to the rotor of the yoke facing in the axial direction across the permanent magnet are connected by a back yoke so that the field magnetic flux is closed,
The two electric current to the yoke in subjecting winding of the stator in the opposite direction, the direction of the current flowing through the windings facing the rotor of the field as the direction of the same at right angles to the magnetic field by the permanent magnet A direct current motor characterized by generating torque in the same direction in a rotor. 2. The DC motor according to claim 1, wherein the teeth at different positions are connected by crossing back yokes connecting the two teeth on the opposite rotor side of the opposing yokes.
The two teeth on the anti-rotor side of each yoke on the one stator side and the two teeth on the anti-rotor side of each yoke on the other stator side are relatively relative to each other by two back yokes. 2. The DC motor according to claim 1, wherein the DC motor is connected by being shifted in the circumferential direction by an amount corresponding to the amount.

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