JP2013115970A - Commutator motor and electric apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a commutator motor capable of preventing reduction of torque, reducing harmonic components of the current and suppressing the increase of iron loss.SOLUTION: The commutator motor includes: a field core 31 of a rectangular tube shape on which a field winding is wound; and an armature which is rotatably provided in the tube of the field core 31. The field core 31 includes a pair of magnetic pole parts 35. The magnetic pole parts 35 are disposed to face the armature while facing each other. Each of the magnetic pole parts 35 has a cut-off 35n formed in a plane facing the armature at the upstream side in a rotation direction of the armature.

Description

  The present invention relates to a commutator motor provided in an electric device such as an electric blower or a vacuum cleaner equipped with the electric blower.

  Conventionally, in this type of commutator motor, a technique has been proposed in which the gap width is narrowed from the center of the magnetic pole of the field core to the end in order to suppress the waveform distortion of the load current and reduce the harmonic current component. (For example, refer to Patent Document 1).

  FIG. 5 is a plan view showing a configuration of a conventional commutator motor described in Patent Document 1. As shown in FIG. As shown in FIG. 5, the conventional commutator motor includes a field core 92 having a magnetic pole portion 92 b and an armature core 94, and a gap 95 is provided between the field core 92 and the armature core 94. ing. The relationship between the gap width Ga of the gap 95a at the end of the magnetic pole portion 92b and the gap width Gb of the gap 95b at the center of the magnetic pole portion 92b is Ga <Gb.

JP 2002-34183 A

  In this type of commutator motor, the magnetic fluxes generated from the field coil and the armature coil when energized are combined, respectively. The combined magnetic flux flows in a direction deviating from the direction in which the magnetic poles face each other. For this reason, the magnetic flux is concentrated in a partial region of the magnetic pole of the field core to cause magnetic saturation, which causes an increase in harmonic components of the current and an increase in iron loss of the field core.

  FIG. 6 is a magnetic flux diagram showing the flow of magnetic flux in a conventional general commutator motor. In FIG. 6, in order to visualize the flow of magnetic flux during energization, calculation was performed using CAE used for structural analysis and the like. As can be seen from FIG. 6, the magnetic flux in the field core flows in a direction shifted from the direction in which the magnetic poles face each other. The magnetic flux is concentrated on the upstream side in the rotation direction of the magnetic pole of the field core due to the deviation of the flow of the magnetic flux.

  FIG. 7 is a magnetic flux density distribution diagram showing a magnetic flux density distribution in a conventional general commutator motor. As shown by the arrows in FIG. 7, the magnetic flux density is highest in the region indicated by the arrow on the upstream side in the rotation direction of the magnetic pole of the field core, and magnetic saturation occurs in this region.

  Thus, in order to alleviate magnetic saturation, the gap width only in the vicinity of magnetic saturation should be widened.

  However, in the case of the configuration as described in Patent Document 1 described above, the gap width is wide at the center and narrows toward the end. For this reason, the gap is widened to a portion that does not need to be widened. As a result, there is a problem that the magnetic resistance increases, the generated magnetic flux decreases, and the torque decreases.

  The present invention solves such a conventional problem. A commutator motor capable of suppressing a decrease in torque and suppressing an increase in harmonic components of current and an increase in iron loss, and an electric motor including the commutator motor are provided. The purpose is to provide equipment.

  In order to achieve such an object, a commutator motor according to the present invention is provided rotatably including a field including a rectangular cylindrical field core wound with a field winding and a field core. A commutator motor comprising the armature provided. The field core includes a pair of magnetic pole portions, and the magnetic pole portions face the armature and are disposed so as to face each other. And it is the structure which provided the notch in the upstream of the rotation direction in the surface which faces the armature of this magnetic pole part.

  As a result, the magnetic resistance is locally increased by the notch only in the vicinity of the magnetic saturation region, so that the magnetic flux in the magnetic saturation portion of the magnetic pole portion is dispersed, and the magnetic saturation in this region can be relaxed. it can.

  Moreover, the electric device of the present invention is configured to include such a commutator motor.

  Since the commutator motor of the present invention can alleviate magnetic saturation, the harmonic component of the current is reduced, and an increase in iron loss can be suppressed. Further, since the magnetic resistance is locally increased, it is possible to suppress a decrease in torque.

The block diagram which shows the structure of the electric blower provided with the commutator motor in embodiment of this invention The top view which shows the field core and armature core of the commutator motor Top view showing the commutator motor press-fitted into the bracket Plan view of field core of commutator motor Plan view showing the configuration of a conventional commutator motor Magnetic flux diagram showing the flow of magnetic flux in a conventional general commutator motor Magnetic flux density distribution diagram showing magnetic flux density distribution in a conventional general commutator motor

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment)
An electrical device using a commutator motor in an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an electric blower using the commutator motor provided in an electric device such as a vacuum cleaner will be described as an example of such an electric device.

  FIG. 1 is a configuration diagram illustrating a configuration of an electric blower 10 including a commutator motor 20 according to an embodiment of the present invention.

  As shown in FIG. 1, the electric blower 10 has a configuration in which the commutator motor 20 of the present embodiment is provided in a cylindrical bracket 12 that is closed on one side and opened in the opposite direction. The commutator motor 20 includes a stator 30 that is a field and a rotor 40 that is an armature.

  The stator 30 has a field winding 32 wound around a field core 31 having a rectangular cylindrical shape. Such a stator 30 is fixed inside the bracket 12.

  On the other hand, the rotor 40 includes an armature core 41, an armature winding 42, a rotating shaft 43, and a commutator 45. An armature winding 42 is wound around the armature core 41, and a rotary shaft 43 is coupled so as to penetrate the center of the armature core 41. The rotor 40 is rotatably supported at both ends of the rotating shaft 43 by the bearings 13. Further, a commutator 45 is disposed on the rotating shaft 43.

  A brush holder 14 is fixed to the bracket 12. Further, the brush holder 14 holds a pair of carbon brushes (not shown). The pair of carbon brushes are in contact with the commutator 45. The commutator motor 20 is configured as described above.

  In the electric blower 10, a fan case 15 is attached so as to cover the opened side of the bracket 12. The rotating shaft 43 of the rotor 40 protrudes from the opening of the bracket 12 and enters the fan case 15. The centrifugal fan 16 is attached to the tip of the rotating shaft 43 that has entered. An air guide 17 is attached between the centrifugal fan 16 and the opening of the bracket 12. Thus, the centrifugal fan 16 and the air guide 17 are disposed in the fan case 15.

  In the electric blower 10 configured as described above, when electric power is supplied to the commutator motor 20 from the outside, an armature current flows to the armature winding 42 via the carbon brush (not shown) and the commutator 45. At the same time, a field current flows through the field winding 32 of the stator 30. A force is generated between the magnetic flux generated in the field core 31 by the field current and the armature current flowing through the armature winding 42, and the rotor 40 rotates. As the rotor 40 rotates, the centrifugal fan 16 rotates. By this rotation, air is sucked from the intake port 18 and flows into the centrifugal fan 16 and is discharged out of the electric blower 10 through the bracket 12.

  Next, a more detailed configuration of the commutator motor 20 will be described.

  FIG. 2 is a plan view showing field core 31 and armature core 41 of commutator motor 20 in the embodiment of the present invention.

  The field core 31 is formed by first punching a magnetic steel sheet into a rectangular frame shape having an opening on the inside as shown in FIG. 2, and further stacking a plurality of field core materials formed by punching. It is composed of that. By comprising in this way, the field core 31 has comprised the shape of a square cylinder. The field core 31 has a rectangular frame-shaped frame portion 34 and a pair of opposed magnetic pole portions 35 formed at the opening. The field winding 32 is wound around both the magnetic pole portions 35. The armature core 41 is disposed in the field core 31 so as to be sandwiched between the magnetic pole portions 35.

  FIG. 3 is a top view showing a state in which the commutator motor 20 according to the embodiment of the present invention is press-fitted into the bracket 12.

  As shown in FIG. 3, field windings 32 are wound around both the magnetic pole portions 35 of the field core 31. Between the magnetic pole portions 35, a rotor 40 is disposed in which an armature winding 42 is wound around an armature core 41 with a rotating shaft 43 as a center. A contact surface is formed at each corner 34 a of the field core 31 along the direction of the rotation axis 43 of the bracket 12. The abutment surface is pressed against the inner peripheral surface of the bracket 12, and the stator 30 having the field winding 32 wound around the field core 31 is fixed in the bracket 12.

  As described above, the commutator motor 20 is provided rotatably in the cylinder of the field core 31 and the stator 30 that is a field including the rectangular cylindrical field core 31 around which the field winding 32 is wound. And a rotor 40 which is an armature. The pair of magnetic pole portions 35 included in the field core 31 face the rotor 40 and are disposed so that the magnetic pole portions 35 face each other.

  Next, further details of the field core 31 will be described.

  FIG. 4 is a plan view of the field core 31 of the commutator motor 20 in the embodiment of the present invention.

  About the outline | summary of the field core 31, it has a pair of magnetic pole part 35 which opposes as mentioned above. As shown in FIG. 4, the magnetic pole part 35 includes a base part 35a that protrudes inward from the center of one side of the frame part 34, and magnetic pole protrusions 35b and 35c that extend so as to protrude further in two directions from the base part 35a. And have. Further, the innermost peripheral side of the magnetic pole portion 35 is formed in an arc shape along the outer peripheral shape of the armature core 41. In such a state, the innermost peripheral surface of the magnetic pole part 35 and the outer peripheral surface of the rotor 40 face each other. And as shown in FIG. 4, the notch part 35n which is a notch used as a hollow is provided in the inner peripheral side of one magnetic pole protrusion part 35b.

  The magnetic pole protrusion provided with the notch 35n is a magnetic pole protrusion on the upstream side in the rotation direction with respect to the rotating rotor 40. Accordingly, in the case of FIG. 4, a notch 35n is provided on the upstream magnetic pole projection 35b. Further, the magnetic pole protrusion 35c on the other downstream side is not provided with such a notch 35n. In other words, the magnetic pole protrusion 35c is formed so that the width becomes narrower as it approaches the tip. On the other hand, the magnetic pole projection 35b is formed so as to be narrow once in the vicinity of the middle between the base 35a and the tip by providing a notch 35n.

  As described with reference to FIGS. 6 and 7, in the field core, the magnetic flux flows in a direction shifted from the direction in which the magnetic poles face each other, and the magnetic flux density is highest in the region indicated by the arrow in FIG. It will be.

  Therefore, in the present embodiment, a notch 35n is provided in the magnetic saturation region, that is, the magnetic pole protrusion 35b, so that the gap width with the rotor 40 is larger than that in the other regions. Thereby, the magnetic resistance is locally increased at the magnetic pole protrusion 35b having the highest magnetic flux density. Then, by increasing the magnetic resistance with respect to the high magnetic flux density region, the flow of magnetic flux is dispersed and the magnetic saturation is relaxed.

  As described above, in the present embodiment, the notch 35 n is provided on the upstream side in the rotation direction of the rotor 40 on the surface facing the rotor 40 of the magnetic pole portion 35. Thereby, a magnetic resistance can be increased with respect to a high magnetic flux density region, and magnetic saturation can be relaxed. Thus, in this Embodiment, since magnetic saturation can be relieved, the increase in the harmonic component of an electric current and an iron loss can be suppressed. Furthermore, since the magnetic resistance is increased only for the high magnetic flux density region, it is possible to suppress a decrease in torque.

  As described above, in the commutator motor of the present invention, the field core includes the pair of magnetic pole portions, and the magnetic pole portions face the armature and are arranged so as to face each other. And it is the structure which provided the notch in the upstream of the rotation direction in the surface which faces the armature of this magnetic pole part. Since the commutator motor of the present invention is configured as described above, the magnetic flux in the portion where the magnetic saturation of the magnetic pole portion has been dispersed is dispersed, and the magnetic saturation in this region is alleviated. And since the magnetic saturation of this area | region can be relieve | moderated, according to this invention, the fall of a torque can be prevented, the harmonic component of an electric current can be reduced, and the increase in a core loss can be suppressed.

  As described above, the commutator motor according to the present invention can reduce the harmonic component of the current without reducing the torque and suppress the increase in iron loss. Applicable to electrical equipment such as vacuum cleaners.

DESCRIPTION OF SYMBOLS 10 Electric blower 12 Bracket 13 Bearing 14 Brush holder 15 Fan case 16 Centrifugal fan 17 Air guide 18 Inlet 20 Commutator motor 30 Stator 31,92 Field core 32 Field winding 34 Frame part 34a Corner part 35, 92b Magnetic pole Part 35a Base part 35b, 35c Magnetic pole protrusion 35n Notch part 40 Rotor 41, 94 Armature core 42 Armature winding 43 Rotating shaft 45 Commutator 95, 95a, 95b Gap

Claims (2)

A commutator motor comprising a field including a rectangular cylindrical field core wound with a field winding, and an armature provided rotatably in a cylinder of the field core,
The field core includes a pair of magnetic pole portions,
The magnetic pole portions face the armature and are arranged so as to face each other,
A commutator motor characterized in that a notch is provided on the upstream side in the rotation direction on the surface of the magnetic pole portion facing the armature. An electric device comprising the commutator motor according to claim 1.

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