JP4269707B2 - Commutator motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a commutator motor provided in an electric blower or an electric device such as a vacuum cleaner equipped with the electric blower, and more particularly to a commutator motor having improved efficiency and stable rectification .
[0002]
[Prior art]
The iron core shape of the conventional commutator motor is shown in FIG. In the figure, G1a is the first gap width at a position rotated approximately 15 degrees from the pole center, G2a is the second gap width at a position rotated approximately 40 degrees from the pole center, and G3a is rotated approximately 60 degrees from the pole center. This is the third gap width at the position.
[0003]
The gap width of the commutator motor constituted by the field core shown in FIG. 6 is larger than the gap width G1a and larger than the gap width G2a so that the gap width increases as the distance from the center of the pole increases. The unequal gap width.
[0004]
Further, the gap width of the conventional commutator motor is uniform (see, for example, Patent Document 1).
[0005]
The field core and the armature core can be punched from the same iron plate, and the field core is composed of one piece without being divided.
[0006]
Next, the operation of the commutator motor will be described. When a voltage is applied to the field winding, a current flows to the armature winding via the brush and the commutator, and the main magnetic flux φf generated by the field winding Rotational torque is obtained by the current flowing through the armature winding.
[0007]
However, the main magnetic flux φf generated by the current flowing in the field winding is inclined with respect to the center of the magnetic pole due to the influence of the magnetic flux φa which is different from the main magnetic flux φf generated by the current of the armature winding by about 90 degrees. Flowing.
[0008]
This inclination locally increases the magnetic flux density at the teeth of the field core, which makes it difficult for the main magnetic flux to flow, increasing the power harmonic current, and making it difficult to achieve stable rectification as voltage rectification. It was a factor.
[0009]
Furthermore, since the maximum magnetic flux density of the armature teeth also increases at the same time, the armature iron loss increases, causing a reduction in efficiency.
[0010]
Conventionally, for such inclination of the main magnetic flux φf, the magnetic field density is changed by changing the shape on the field slot side so that the cross-sectional area of the magnetic teeth in the rotor rotating direction is smaller than the field teeth in the counter rotating direction. An example of improving the difference between the two is shown (for example, see Patent Document 2).
[0011]
In addition, a motor having a stator winding type has a difference DA between the outer diameter DF of the field core and the outer diameter DA of the armature core disposed inside the field core, although a difference may occur depending on the cooling conditions. / DF is generally set to approximately 0.5.
[0012]
This is because the iron core shape with high motor efficiency is determined empirically from the distribution of winding loss and iron loss, and this ratio is considered to be appropriate.
[0013]
However, in a commutator motor, it is necessary to select an appropriate ratio in consideration of the condition that stable rectification can be ensured.
[0014]
[Patent Document 1]
Japanese Patent Laid-Open No. 57-7878
[Patent Document 2]
JP 2000-92755 A [0016]
[Problems to be solved by the invention]
However, in the conventional commutator motor, the armature iron loss and the mechanical loss increase as the rotational speed increases. In particular, the eddy current loss of the armature core increases with the number of revolutions or the magnetic flux density from 1.6 to the second power.
[0017]
Further, even if the width of the field tooth is expanded to the slot side, there is little improvement in the magnetic flux flow of the armature core being inclined, the magnetic flux density of the armature tooth at the position rotated approximately 15 degrees is the highest, and the magnetic flux Centralization will not be improved.
[0018]
Further, the high-speed rotation shortens the time during which the rectification action proceeds while the commutator piece is in contact with the brush. For this reason, the commutation end stage is reached in a state where the commutation is insufficient, and a rapid current change occurs, so that the reactance voltage generated in the rectification coil increases, and a spark is likely to occur when the commutator piece is separated from the brush.
[0019]
Furthermore, when the rotational speed is close to the critical speed (resonance frequency) of the rotating shaft, the vibration of the electric motor increases rapidly, making it difficult to continue stable operation.
[0020]
Due to these problems, the efficiency and reliability during high-speed rotation are reduced. Therefore, in order to improve the efficiency during high-speed rotation, improvement of iron loss and rectification are strongly demanded.
[0021]
In order to improve the efficiency of the electric blower, a higher-speed commutator motor is required. In other words, the centrifugal fan attached to the tip of the output shaft connected to the armature core rotates at a high speed, so that centrifugal force is generated in the air in the fan and a pressure rise is obtained. This is because high-speed rotation is effective in improving the fan efficiency, which can increase the fan efficiency of the electric blower.
[0022]
Therefore, from the viewpoint of use for an electric blower or the like, as long as reliability such as rectification of the electric motor is ensured, operation at high speed rotation is required as much as possible, and a highly efficient commutator electric motor is required. .
[0023]
An object of the present invention is to increase the efficiency of a commutator motor during high-speed rotation and to provide a commutator motor with stable commutation.
[0024]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, and in order to achieve the above object, the commutator motor of the present invention is formed between an inner diameter of a field core made of a laminated core and an outer diameter of the armature core. The first gap width in the range rotated from 10 degrees to 25 degrees from the pole center of the field core is the second gap width in the position rotated from 35 degrees to 45 degrees. The third gap width at the tooth tip of the field core having a position smaller than the gap width of 55 ° to 65 ° is set to be larger than the second gap width.
[0025]
In the commutator motor according to the present invention, the gap width at the pole center of the field core is made smaller than the first gap width.
[0026]
Furthermore, in the commutator motor of the present invention, the ratio DA / DF of the outer diameter DF of the field core and the outer diameter DA of the armature core is 0.44 to 0.46.
[0027]
As a result, it is possible to improve the increase in loss, particularly the increase in armature iron loss, which is a problem when speeding up the commutator motor, and to obtain a stable commutation state, which is highly efficient and highly reliable. A commutator motor can be obtained. Thus, the first invention of the means for solving the problem is a field core in which a pair of field windings are wound, and an armature winding disposed inside the field core in the slot. The armature core to be housed is constituted by a laminated core, and has an output shaft at the center of the armature core, and when a voltage is applied to the field winding, the armature winding is interposed via a brush and a commutator. In a commutator motor in which a current flows through a wire and a rotational torque is obtained in the output shaft by a main magnetic flux generated by a field winding and a current flowing in an armature winding,
The first gap at a position where the gap width formed between the inner diameter of the field core and the outer diameter of the armature is rotated from the pole center of the field core by an angle equivalent to the main magnetic flux tilt angle caused by the armature reaction. A structure in which the second gap width at a substantially intermediate position between the main magnetic flux inclination angle and the arc angle to the tip of the field core is smaller than the first gap width, and the field core teeth The gap width between the configuration in which the third gap width at the tip is larger than the second gap width and the armature core at the pole center of the field core is greater than the first gap width at the position of the main magnetic flux tilt angle. A commutator motor having a reduced configuration.
[0028]
The second invention of the means for solving the problem is that in the above-mentioned invention, the position of the main magnetic flux inclination angle as the first gap width is about 10 from the pole center of the field core as viewed from the center of the output shaft. and configured to position the scope rotated whenever one et 25 °, a substantially intermediate position between the second said main magnetic flux inclination angle and the field core exhibition firing angle of the tooth to the tip of which a gap width of the field core A configuration in which it is positioned in a range rotated approximately 35 to 45 degrees from the pole center, and the position of the arc angle from the pole center of the field iron core to the tooth tip of the field iron core as the third gap width is approximately 55. The commutator motor is configured to be positioned in a range rotated from 65 degrees to 65 degrees.
[0029]
According to a third aspect of the present invention, there is provided a first and second aspect of the invention having a pair of field windings and a rotor armature winding. In the commutator motor in which the armature is composed of a laminated core, the ratio DA / DF between the outer diameter DF of the field core and the outer diameter DA of the armature core is 0.44 to 0.46. .
[0030]
According to a fourth aspect of the present invention, there is provided an electric device including the commutator motor according to the above aspect.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
The commutator motor of the present application is a laminated iron core comprising a field core wound with a pair of field windings and an armature core disposed inside the field core and accommodating the armature winding in a slot. in constructed, above the center of the armature core have a output shaft, a current flows through the a voltage is applied to the field winding via a brush and the commutator the armature winding, field coil Rotational torque is obtained on the output shaft by the main magnetic flux generated by the wire and the current flowing through the armature winding, and the gap width formed between the inner diameter of the field core and the outer diameter of the armature is set to the main torque generated by the armature reaction. A substantially intermediate position between the main magnetic flux inclination angle and the arc angle to the teeth tip of the field core with respect to the first gap width at a position rotated from the pole center of the field iron core by an angle equivalent to the magnetic flux inclination angle. The second gap width is smaller than the first gap width, and the field core The third gap width at the tooth tip is one having to become larger than the second gap width. The main magnetic flux φf generated by the current of the field winding flows in an inclination with respect to the pole center of the field due to the influence of the magnetic flux φa generated by the current of the armature winding. Although the magnetic flux density of the tooth part of the armature core is locally increased, the first gap width is made larger than the second gap width to provide a difference in magnetomotive force from the field core to the armature core. The magnetic flux flowing in the child teeth is dispersed without concentrating, the amount of magnetic flux flowing to the armature core is equalized, and the total magnetic flux amount can be increased while suppressing the maximum magnetic flux density of the rotating armature teeth.
[0032]
Further, the armature core comprising a pair of field windings and the armature core disposed inside the field core and accommodating the armature winding in a slot is constituted by a laminated core, and the armature In a commutator motor having an output shaft in the center of the iron core, the gap width formed between the inner diameter of the field core and the outer diameter of the armature rotates about 15 degrees from the pole center of the field core as viewed from the output shaft. The second gap width at the position rotated about 40 degrees relative to the first gap width at the position is smaller than the first gap width, and the third gap width at the teeth tip of the field core at the position rotated approximately 60 degrees is those having to become larger than the second gap width. The main magnetic flux φf generated by the current of the field winding flows at an angle of about 15 degrees with respect to the pole center of the field due to the influence of the magnetic flux φa generated by the current of the armature winding. Magnetic flux cores and armature core teeth are locally increased in magnetic flux density. In this way, the magnetic flux distribution of armature core teeth at a position rotated approximately 15 degrees from the center of the pole where the magnetic flux density is increased is made even. It is possible to increase the total amount of magnetic flux while suppressing the maximum magnetic flux density of the rotating armature teeth.
Further, those having that a gap width between the pole center of the armature core of the field core and smaller than the first gap width. The main magnetic flux φf generated by the current of the field winding flows at an inclination of approximately 15 degrees with respect to the pole center of the field due to the influence of the magnetic flux φa generated by the current of the armature winding. The magnetic flux density in the teeth part of the field core or armature core is locally increased, but the first gap width is made larger than the second gap width to provide a difference in magnetomotive force from the field core to the armature core. As a result, the magnetic flux flowing in the armature teeth is dispersed without being concentrated. In addition, since the core cross-sectional area in the range where the magnetic flux density of the field teeth tends to increase is increased, the increase in magnetic resistance can be suppressed and the total magnetic flux increases, and the magnetic flux at the tip of the field teeth follows the change in applied voltage. Therefore, stable voltage rectification is possible.
[0033]
A commutator motor comprising a laminated core comprising a field core formed by winding a pair of field windings and an armature core disposed inside the field core and accommodating the armature winding in a slot. in a commutator motor having that a ratio DA / DF between the outer diameter DA of the outer diameter DF and armature core of the field core and 0.44 to 0.46, the magnetic resistance of the armature is increased It is possible to suppress the amount of magnetic flux generated by the current flowing through the armature winding, and the inclination of the magnetic flux flow can be reduced, and the increase in magnetic flux density due to the magnetic flux concentration generated in the field teeth and armature teeth can be suppressed.
[0034]
The invention according to this application is the electrical equipment that have been provided with a commutator motor described above.
[0035]
【Example】
Hereinafter, specific examples of the present invention will be described with reference to the drawings.
[0036]
Example 1
FIG. 1 shows an iron core shape of a commutator motor according to an embodiment of the present invention. In FIG. 1, G0 is the gap width at the center of the field pole, G1 is the first gap width at a position rotated approximately 15 degrees from the pole center, and G2 is the second gap at a position rotated approximately 40 degrees from the pole center. The gap width, G3, is a third gap width in the vicinity of the tip of the field teeth rotated approximately 60 degrees.
[0037]
Here, selection of the gap width G1 will be described. FIG. 2 shows the relationship between the arrangement angle of the gap width G1 and the armature iron loss. According to this, it can be seen that the arrangement angle of the gap width G1 is 15 degrees, which is the lowest armature iron loss. However, there is no problem if it is practically in the range of 10 to 25 degrees.
[0038]
The position where the gap formed between the inner diameter of the field core and the outer diameter of the armature is rotated from the pole center of the field core by an angle equivalent to the main magnetic flux tilt angle caused by the armature reaction, that is, the pole center Is expanded so as to have a gap width G1 larger than the gap width G0 at a position rotated approximately 15 degrees in the counter-rotating direction. Further, the field iron core is formed in an R shape so that the gap width is equal from the point where the gap width G1 is reached, and then the field teeth shape is made a straight line from an arbitrary position and rotated about 40 degrees in the counter-rotating direction from the pole center. The gap width at this position is reduced so as to be a gap width G2 smaller than the gap width G1.
[0039]
Further, the gap width increases as it moves in the counter-rotating direction, and the gap width G3 is larger than the gap width G2 at the position rotated approximately 60 degrees, and then the gap width is gradually increased toward the tip of the field teeth. ing.
[0040]
That is, the gap width expands, contracts, expands and expands in the counter-rotating direction from the pole center. Specifically, the gap width G0 is set to 1.0, the gap width G1 is set to 1.4, the gap width G2 is set to 1.0, and the gap width G3 is set to 1.4.
[0041]
Here, the specific effect of the commutator motor having the above configuration will be described. When the armature iron loss is 1100 w, the conventional armature loss is 35 w, but according to the commutator motor of this embodiment, it is reduced to 21 w. We were able to.
[0042]
The field teeth shape only needs to be secured by sequentially (smoothly) changing the predetermined gap width at each angle position, and is not limited to the field teeth shape between the angle positions. That is, the space may be formed with an R shape and a linear shape, or may be formed with a linear shape.
[0043]
Further, the gap width in the rotation direction is not particularly limited, and may be symmetric with respect to a predetermined uniform width or counter-rotation direction, for example.
[0044]
(Example 2)
The inclination of the main magnetic flux φf caused by the influence of the magnetic flux φa due to the armature current causes local concentration of the magnetic flux density. However, the magnetic flux φa due to the armature current does not contribute to the generation of the rotational torque of the motor, and is suppressed. It is desirable.
[0045]
When the armature magnetomotive force is larger than the magnetomotive force of the entire motor, that is, when the magnetic resistance of the armature core is large, φa is smaller than the main magnetic flux φf, so the inclination of the main magnetic flux is reduced. Reducing the tooth width of the armature core increases the magnetic resistance of the armature core. Therefore, it is possible to suppress the inclination of the magnetic flux without reducing the outer diameter DA of the armature core. However, it is necessary to increase the mechanical strength of the output shaft, and the weight reduction of the armature core improves the critical speed of the output shaft. It is desirable to make it smaller.
[0046]
When the outer diameter ratio of the iron core is reduced, the width of the armature teeth and the slot cross-sectional area are inevitably reduced, and the armature magnetic resistance and the armature winding resistance are increased. The distribution ratio between the magnetic resistance and the field resistance of the winding resistance and the armature has a correlation with the brush life, and the appropriateness of the distribution ratio is linked to the iron core outer diameter ratio. Therefore, by taking the iron core outer diameter ratio as an index, the shape of the iron core of the commutator motor can be made appropriate for the application.
[0047]
FIG. 3 shows the relationship between the iron core outer diameter ratio and the brush life or the armature copper loss. Here, the brush life can be secured for about 600 hours at an iron core outer diameter ratio of 0.46.
[0048]
It can also be seen that the armature copper loss increases rapidly when the iron core outer diameter ratio exceeds 0.44. This is because if the iron core outer diameter ratio is reduced, the slot cross-sectional area of the armature and the armature teeth cannot be increased, and this causes an increase in iron loss and copper loss.
[0049]
The iron core outer diameter ratio is the ratio between the field iron core outer diameter DF and the armature iron core outer diameter DA (see FIG. 1). Specifically, the armature iron core outer diameter DA is φ34.2, the field magnet When the iron core outer diameter DF is φ77, the iron core outer diameter ratio DA / DF is 0.44.
[0050]
Here, the specific effect of the commutator motor having the above configuration will be described. Although the copper loss is 77w in the past, it increases to 81w. The total loss of iron loss and copper loss was reduced by 10 w, while the rectification was stabilized and the brush life time was 500 hours, but it could be extended to 600 hours.
[0051]
As described above, setting the iron core outer diameter ratio DA / DF to a value of 0.44 to 0.46 is appropriate for a commutator motor used in an electric blower.
[0052]
(Example 3)
FIG. 4 shows an electric blower provided with the commutator motor of the present invention.
[0053]
In the commutator motor, when a voltage is applied to the field winding 5, a current flows to the armature winding 6 via the brush 3 and the commutator 4, and the main magnetic flux φf generated by the field winding 5 and the armature winding A rotational torque is obtained by the current flowing through the wire 6.
[0054]
When the armature 1 attached rotatably in the field 2 rotates, the centrifugal fan 8 attached to the tip of the output shaft 7 of the armature 1 rotates, and the air sucked from the centrifugal fan 8 is sucked. After being guided into the electric motor through the air guide 9, the air is discharged outside.
[0055]
FIG. 5 shows a vacuum cleaner in which the electric blower is mounted on the main body 54. The vacuum cleaner sucks air containing dust from the suction port 50 through the hose 52. The suction force is obtained by rotating the centrifugal fan 8 attached to the output shaft 7 of the commutator motor. In addition, since it is necessary to rotate the centrifugal fan 8 at high speed in order to obtain a high suction force, a commutator motor that is easy to rotate at high speed is used.
[0056]
【The invention's effect】
As is apparent from the above description, according to the first invention, after the gap width is sequentially increased from the pole center of the field core to an angle equivalent to the main magnetic flux inclination angle generated by the armature reaction, the rotation is performed in the rotational direction. As the gap width is gradually reduced, the armature iron loss can be greatly reduced and the magnetomotive force when the maximum magnetic flux amount is generated is reduced, so that the generation of power supply harmonic current can be reduced and the rectifying action is improved. An advantageous effect is obtained.
[0057]
According to the second invention, the armature iron loss can be greatly reduced, and the advantageous effect that the magnetomotive force when the maximum magnetic flux amount is generated is reduced.
[0058]
According to the third aspect of the invention, it is possible to contribute to the improvement of the rectification action, and both rectification stabilization and efficiency maintenance can be achieved. Furthermore, since the space formed between the outer periphery of the field core and the bracket around the motor body occupies the main part of the cross-sectional area of the ventilation path as an electric blower, the cross-sectional area of the ventilation path is reduced as the iron core outer diameter ratio is reduced. Is easy to secure. Furthermore, when implemented together with the first invention , it is possible to improve efficiency and stabilize rectification.
[Brief description of the drawings]
FIG. 1 is a diagram showing a field core and an armature core of a commutator motor according to an embodiment of the present invention. FIG. 2 is an electric machine with respect to an arrangement angle of a first gap width of a commutator motor according to an embodiment of the present invention. FIG. 3 is a diagram showing a correlation between core iron losses. FIG. 3 is a diagram showing a correlation between brush life and armature copper loss with respect to an iron core outer diameter ratio of a commutator motor according to an embodiment of the present invention. FIG. 5 is a diagram showing an electric vacuum cleaner equipped with an electric blower equipped with the commutator motor of the present invention. FIG. 6 shows a field core and an armature core of a conventional commutator motor. Figure [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Armature 2 Field 3 Brush 4 Commutator 5 Field winding 6 Armature winding 7 Output shaft 8 Centrifugal fan 9 Air guide G0 Gap width of pole center G1 First gap of about 15 degree rotation position from pole center Width G2 Second gap width at approximately 40 degree rotation position from pole center G3 Third gap width at approximately 60 degree rotation position from pole center DF Field core outer diameter DA Armature core outer diameter

Claims (4)

The armature core includes a field core formed by winding a pair of field windings and an armature core that is disposed inside the field core and accommodates the armature winding in a slot. of the center have a output shaft, the field when voltage winding is applied a current flows in the armature winding through the brushes and the commutator, the main magnetic flux and the armature caused by the field winding In a commutator motor that can obtain a rotational torque on the output shaft by a current flowing in a winding ,
The first gap at a position where the gap width formed between the inner diameter of the field core and the outer diameter of the armature is rotated from the pole center of the field core by an angle equivalent to the main magnetic flux tilt angle caused by the armature reaction. A structure in which the second gap width at a substantially intermediate position between the main magnetic flux inclination angle and the arc angle to the tip of the field core is smaller than the first gap width, and the field core teeth configuration and the third gap width was greatly than the second gap width at the tip, the gap width between the pole center of the armature core of the field core, the first gap width position of the main magnetic flux tilt angle A commutator motor having a smaller configuration . A configuration in which the position of the main magnetic flux tilt angle as the first gap width is positioned in a range rotated from about 10 degrees to 25 degrees from the pole center of the field core as viewed from the center of the output shaft, and the second gap width as described above A configuration in which a substantially intermediate position between the main magnetic flux inclination angle and the arc angle of the field core to the tooth tip is positioned in a range rotated approximately 35 to 45 degrees from the pole center of the field core, and a third gap rectifier according to claim 1 having a configuration as to be positioned in a range where the position of the field core of the tooth tip to the exhibition firing angle rotated 65 degrees from substantially 55 degrees from the pole center of the field core to a width Child electric motor. In a commutator motor having a pair of field windings and a rotor armature winding, the field and the armature being formed of a laminated core, the outer diameter DF of the field core and the armature core The commutator motor according to any one of claims 1 to 2, wherein a ratio DA / DF of the outer diameter DA is set to 0.44 to 0.46. Electrical equipment that immediately Started the commutator motor as claimed in any one of claims 3.

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