JP2009291038A - Commutator motor and vacuum cleaner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a commutator motor capable of suppressing spark between a brush and a commutator by improving an armature core as a source causing spark between the brush and the commutator. <P>SOLUTION: The commutator motor 1 comprises a stator 20 composed by stacking a plurality of steel sheets with a plurality of magnetic poles formed at the inner peripheral part thereof, an armature 10 in which an armature coil 12 is wound around an armature core 11 composed by stacking the plurality of steel sheets and turnably provided on the inner peripheral side of the magnetic poles, a commutator 5 prepared in a rotary shaft 4 of the armature 10, and connected to the armature coil 12, and a brush 6 in contact with the commutator 5. The armature core 11 is composed of steel sheets each having a smaller coercive force than that of a non-oriented electromagnetic steel sheet. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a commutator motor and a vacuum cleaner equipped with the commutator motor, and more particularly, a commutator motor designed to suppress sparks generated between a brush and a commutator, and a vacuum cleaner equipped with the commutator motor. Related to the machine.

Generally, in order to extend the life of a brush provided in a commutator motor, it is known that it is effective to suppress sparks generated between the brush and the commutator. As a conventional commutator motor that suppresses the spark generated between the brush and the commutator in this way, for example, “5 is an AC power source, 6 is a rectifier that converts the output of the AC power source into a full-wave rectified pulsating flow, 8 is a carbon brush on the plus side, 9 is a metal-graphite brush on the minus side, 7 is a commutator that selectively switches the current to be applied to the rotor winding by the rotational position in sliding contact with the brush, 4 is a rotor A rotor winding (not shown) is wound, and a current is selected from the commutator and energized. 2 is a magnet built in the frame, which is electromagnetic between the current flowing in the rotor winding. A magnetic flux is generated to generate force and rotate the rotor 4. Here, a metal graphite brush is used as the negative brush, so that the electrical resistance of the brush is small and spark discharge is likely to occur. But a capacitor in parallel with the power supply The spark discharge is suppressed by making the intermittent electric current caused by the pulsating flow continuous by inserting the ”(for example, see Patent Document 1).
Further, for example, “the commutator 5 is configured by arranging a plurality of segments 8 molded on the insulating member 7 in a cylindrical shape, and the insulating member 7 is fitted to the outer periphery of one end side of the armature shaft 2 by press fitting or the like. The segment 8 is provided with a low resistance layer 8a and a high resistance layer 8b having different electrical resistances on the commutator surface (the surface of the segment 8) on which the brush 6 slides (see FIG. 1). In the layer 8a and the high resistance layer 8b, for example, the low resistance layer 8a has a higher copper content than the high resistance layer 8b, and the low resistance layer 8a has a lower electrical resistance than the high resistance layer 8b. 1, the low-resistance layer 8a and the high-resistance layer 8b are commutated with respect to both ends of the commutator surface, that is, with respect to the rotation direction of the commutator 5 (arrow direction in the figure). The high resistance layer 8b is arranged on the front end side and the rear end side of the segment 8 forming the surface. Those of low-resistance layer 8a between the two high-resistance layer 8b are disposed. "(For example, see Patent Document 2) are proposed.

JP 2008-11699 A (paragraph 0022, FIG. 1) JP 2008-11679 (paragraphs 0014, 0015, FIGS. 1, 3)

  Conventionally, sparks generated between the brush and the commutator have been suppressed by changing the members and structure of the brush and commutator. However, these are inventions for suppressing sparks generated between the brush and the commutator, and are not inventions for suppressing the occurrence of sparks themselves.

  The present invention has been made to solve the above-described problems, and is intended to improve at least one of an armature core and a stator that are sources of sparks generated between a brush and a commutator. Thus, an object of the present invention is to obtain a commutator motor capable of suppressing sparks generated between the brush and the commutator and a vacuum cleaner equipped with the commutator motor.

  A commutator motor according to the present invention is configured by laminating a plurality of steel plates, an stator having a plurality of magnetic poles formed on an inner peripheral portion, and an armature core configured by laminating a plurality of steel plates. An armature in which a winding is wound and provided rotatably on the inner peripheral side of the magnetic pole; a commutator provided on a rotating shaft of the armature and connected to the armature winding; In the commutator motor provided with a brush that contacts the commutator, the armature core is made of a steel plate having a smaller coercive force than the non-oriented electrical steel plate.

  Moreover, the vacuum cleaner which concerns on this invention mounts the said commutator motor.

  According to the inventors' research, it has been found that there is a correlation between the size of the spark generated between the brush and the commutator and the coercive force of the armature core. That is, it was found that the smaller the coercive force of the armature core, the smaller the size of the spark generated between the brush and the commutator. In the present invention, since the armature core is composed of a steel sheet having a coercive force smaller than that of the non-oriented electrical steel sheet normally used for the armature core, it is possible to suppress sparks generated between the brush and the commutator. Can do.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view in the direction parallel to the rotation axis of the commutator motor according to Embodiment 1 of the present invention. The commutator motor 1 includes a frame 2, a bearing 3, a rotating shaft 4, a commutator 5, a brush 6, an armature 10, a stator 20, and the like. The frame 2 includes a hollow bottomed and substantially rectangular parallelepiped frame 2a and a frame 2b, and is joined by a flange formed on the outer peripheral side of each other. A bearing 3a and a bearing 3b are provided at substantially the center of the bottom of the frame 2a and the frame 2b, respectively, and the rotating shaft 4 is rotatably supported by the bearing 3a and the bearing 3b.

  The rotary shaft 4 is provided with an armature core 11 having a plurality of teeth formed on the outer periphery. Each of these teeth is armed with an armature winding 12 to form an armature 10. Further, the rotary shaft 4 is provided with a commutator 5 composed of a plurality of commutator pieces, and an armature winding 12 wound around a tooth portion is connected to each commutator piece. . The commutator 5 is in contact with two brushes 6 for supplying current to the armature winding 12 through commutator pieces. These brushes 6 are attached to a brush holder 7 provided on the frame 2a.

  On the other hand, a stator 20 is provided on the inner periphery of the frame 2a via a predetermined gap from the outer periphery of the armature 10. Two magnetic pole pieces 21 facing each other are formed on the inner peripheral portion of the stator 20 (shown in FIG. 3), and a field winding 22 is wound around each of the magnetic pole pieces 21, A magnetic pole is formed. Each of the field windings 22 has one end connected to a motor terminal (not shown) and the other end connected to the brush 6.

  FIG. 2 is a front view of the armature according to the first embodiment of the present invention (viewed from the direction of the rotation axis). This figure is an exploded view of an armature constructed by laminating a plurality of armature pieces for each armature piece. In addition, the arrow shown to each armature piece shows the rolling direction of a grain-oriented electrical steel sheet.

  As shown in FIG. 2, the armature core 11 has a substantially circular shape, and a plurality of tooth portions are formed on the outer peripheral portion. In addition, a through hole into which the rotating shaft 4 is inserted is formed at a substantially central portion. The armature core 11 is formed by stacking n (n is a natural number) steel plates 101 to 10n having the same shape. These steel plates 101 to 10n are formed by stamping from grain-oriented electrical steel plates with a press or the like. Each of the steel plates 101 to 10n is laminated with the rolling direction of the grain-oriented electrical steel plate shifted by 180 ° / n.

  The grain-oriented electrical steel sheet has a property that magnetic flux easily passes in the rolling direction (hereinafter, the direction in which this magnetic flux easily passes is referred to as an easy magnetization direction). That is, the armature core 11 is configured by laminating the easy magnetization directions of the steel plates 101 to 10n by 180 ° / n. This is because the magnetic flux density in the armature core 11 is averaged to prevent the rotation unevenness (ripple) of the armature 10.

FIG. 3 is a front view (seen from the direction of the rotation axis) of the stator according to Embodiment 1 of the present invention. In addition, the arrow shown in the figure indicates the direction of easy magnetization.
The outer portion of the stator 20 has a substantially square frame shape, and two magnetic pole pieces 21 having a substantially crescent shape are opposed to each other on the inner peripheral portion.

  The stator 20 is divided into a plurality of blocks. Specifically, the stator 20 is divided into blocks 20a to 20f and blocks 21a and 21b. Each of the block 21 a and the block 21 b is a part of the magnetic pole piece 21. The block 20 a and the block 20 b are provided on both sides of the block 21 a and form one side of the outer portion of the stator 20. The block 20d and the block 21e are provided on both sides of the block 21b, and form one side of the outer portion of the stator 20 facing one side formed by the block 20a and the block 20b. The block 20c is provided between the block 20b and the block 20d, and forms one side of the outer portion of the stator 20 that connects one side formed by the block 20a and the block 20b and one side formed by the block 20d and the block 20e. To do. The block 20f is provided between the block 20a and the block 20e, connects one side formed by the block 20a and the block 20b and one side formed by the block 20d and the block 20e, and faces the one side formed by the block 20c. One side of the outer portion of the stator 20 is formed.

  Each of the blocks 20a to 20f and the blocks 21a and 21b is formed by stacking a plurality of block pieces punched out of a grain-oriented electrical steel sheet by a press or the like so that their magnetization easy directions are aligned. The easy magnetization direction of each block is the same as the direction of magnetic flux generated in the stator 20. Specifically, the easy magnetization directions of the block 21a and the block 21b, which are the magnetic pole pieces 21, are opposite to each other. Each of the easy magnetization directions of the blocks 20a to 20f forming the outer portion of the stator 20 is the side direction of the outer portion.

  Next, the operation of the commutator motor 1 configured as described above will be described. When an AC voltage is applied between the motor terminals, a current flows through one of the brushes 6 via the field winding 22 wound around one of the pole pieces 21. A current flows through the armature winding 12 by energization due to the sliding contact between the brush 6 and the commutator 5. A current flows through the field winding 22 wound around the other pole piece 21 via the other brush 6, thereby generating a driving force in the commutator motor 1.

  The driving force of the commutator motor 1 is obtained by a magnetic field generated in the armature core 11 and the pole piece 21 when current flows through the armature winding 12 and the field winding 22. At this time, the direction of the magnetic flux generated in the magnetic pole piece 21 is the opposite direction of the magnetic pole piece 21 as described above. Further, as described above, the stator 20 also generates a magnetic field in the outer portion, and the direction of the magnetic flux at this time is the side direction of the outer portion.

  Here, in the electromagnetic steel sheet generally used for the armature and the stator of the commutator motor, even if the current flowing through the armature winding and the field winding is stopped, that is, the magnetizing force H [A / m ] Even if (the strength of the magnetic field) is set to zero, a hysteresis phenomenon occurs in which the magnetic flux density B [T] does not become zero.

  FIG. 4 shows an example of a general hysteresis curve of the electrical steel sheet. When an external magnetic field (magnetizing force) of h1 [A / m] is applied to the electromagnetic steel sheet, the magnetic flux density of the electromagnetic steel sheet is b1 [T]. When the external magnetic field is decreased, the magnetic flux density of the magnetic steel sheet also decreases, but b2 [T] magnetic flux remains in the magnetic steel sheet even if the external magnetic field is set to zero. By further applying an external magnetic field −h2 [A / m] in the opposite direction to h1 [A / m], the magnetic flux density of the electrical steel sheet becomes zero. When an external magnetic field (magnetizing force) of -h1 [A / m] is applied to the electromagnetic steel sheet, the magnetic flux density of the electromagnetic steel sheet is -b1 [T]. When the external magnetic field is decreased, the magnetic flux density of the magnetic steel sheet also decreases. However, even if the external magnetic field is set to 0, a magnetic flux of -b2 [T] remains in the magnetic steel sheet. By further applying the external magnetic field h2 [A / m], the magnetic flux density of the electrical steel sheet becomes zero. This external magnetic field h2 [A / m] is the coercive force Hc [A / m] of the magnetic steel sheet.

  FIG. 5 is a hysteresis curve obtained by measuring a non-oriented silicon steel plate (manufactured by JFE Steel Corporation, product name “35JN200”), which is an example of a non-oriented electrical steel plate, by a 25 cm Epstein test (JIS C2550). FIG. 6 shows a directional silicon steel sheet (JFE Steel Co., Ltd., product name “27JGSD090”), which is an example of a directional electromagnetic steel sheet, with the easy magnetization direction as the longitudinal direction (that is, generated in the easy magnetization direction and the test piece). It is a hysteresis curve measured by a 25 cm Epstein test (JISC2550) with the direction of the magnetic flux to be performed as the same direction. 5 and 6 show diagrams above the horizontal axis in FIG. As shown in FIG. 5, the coercive force Hc [A / m] of the non-oriented silicon steel sheet is about 30 [A / m]. Further, as shown in FIG. 6, the coercive force Hc [A / m] of the directional silicon steel sheet when the magnetic flux is generated in the same direction as the easy magnetization direction is about 5 [A / m]. That is, the coercive force Hc [A / m] of the directional silicon steel plate when the magnetic flux is generated in the same direction as the easy magnetization direction is smaller than the coercive force Hc [A / m] of the non-oriented silicon steel plate. .

  The above relationship is established in addition to the non-oriented silicon steel plate and the directional silicon steel plate. That is, the coercive force Hc [A / m] of the directional electrical steel sheet when the magnetic flux is generated in the same direction as the easy magnetization direction is smaller than the coercive force Hc [A / m] of the non-oriented electrical steel sheet. The coercive force Hc [A / m] of the directional electrical steel sheet when the magnetic flux is generated in the direction perpendicular to the easy magnetization direction is the coercivity of the directional electrical steel sheet when the magnetic flux is generated in the same direction as the easy magnetization direction. It is larger than Hc [A / m] and smaller than the coercive force Hc [A / m] of the non-oriented electrical steel sheet.

  In energization by the sliding contact between the brush 6 and the commutator 5, a spark is generated between the brush 6 and the commutator 5 when the brush 6 changes the commutator piece. The inventor studied the relationship between this spark and the coercive force Hc [A / m] of the electrical steel sheet, and found the correlation shown in FIG.

  FIG. 7 is a characteristic diagram showing the relationship between the coercive force Hc [A / m] of the electrical steel sheet and the size of the spark generated between the brush 6 and the commutator 5. In this figure, the horizontal axis indicates the coercive force Hc [A / m] of the magnetic steel sheet used as the armature core and stator of the commutator motor 1, and the vertical axis indicates the spark generated between the brush 6 and the commutator 5. Indicates the size. The horizontal axis shows a directional silicon steel plate (JFE Steel Corporation, product name “27JGSD090”) with the easy magnetization direction as the longitudinal direction (that is, the easy magnetization direction and the direction of the magnetic flux generated in the test piece are the same direction). ) The coercivity measured by the 25 cm Epstein test (JISC2550) and the coercivity measured by the 25 cm Epstein test (JISC2550) of a non-oriented silicon steel plate (JFE Steel Corporation, product name “35JN200”) are shown. Note that the size of the spark on the vertical axis is based on the size of the spark when the coercive force Hc [A / m] is 5 [A / m] (= 1).

  As shown in FIG. 7, there is a correlation between the coercive force Hc [A / m] of the magnetic steel sheet and the magnitude of the spark generated between the brush 6 and the commutator 5, and the coercive force Hc [A / m] is large. As it turns out, the size of the sparks also increases.

  That is, in commutator motor 1 configured as in the first embodiment, a directional electrical steel sheet having a smaller coercive force Hc [A / m] than a non-oriented electrical steel sheet normally used as a member of an armature core. Since the armature core 11 is configured as described above, sparks generated between the brush 6 and the commutator 5 can be suppressed. In the first embodiment, the armature core 11 is made of a directional electromagnetic steel sheet. However, the armature 10 is made of a steel sheet having a smaller coercive force Hc [A / m] than the non-oriented electromagnetic steel sheet. The same effect can be obtained.

  Further, since the armature 10 is configured by laminating the respective easy direction of magnetization of the steel plates 101 to 10n by 180 ° / n, the magnetic flux density in the entire armature 10 is averaged and the armature 10 is rotated. Unevenness (ripple) can be prevented. Note that the shift angle of each armature piece is not limited to 180 ° / n, and may be any angle as long as the magnetic flux density generated in the armature core 11 can be averaged.

  The commutator motor 1 according to the first embodiment includes the stator 20 made of a directional electrical steel sheet having a coercive force Hc [A / m] smaller than that of a non-oriented electrical steel sheet normally used as a stator member. Therefore, the spark which generate | occur | produces between the brush 6 and the commutator 5 can be suppressed. In the first embodiment, the armature 10 is composed of a directional electromagnetic steel sheet, but by configuring the armature 10 with a member having a coercive force Hc [A / m] smaller than that of a non-oriented electromagnetic steel sheet, Similar effects can be obtained.

  Further, the stator 20 is divided into a plurality of blocks (blocks 20a to 20f and blocks 21a and 21b), and the easy magnetization direction of each block is the same as the direction of the magnetic flux generated in the stator 20, so that the brush Sparks generated between 6 and the commutator 5 can be further suppressed.

  In addition, in this Embodiment 1, although both the armature core 11 and the stator 20 were comprised with the directional electromagnetic steel plate, even if either is comprised with a directional electromagnetic steel plate, the brush 6 and the commutator 5 and Sparks generated during the period can be suppressed. Further, although the magnetic pole of the stator 20 is configured by winding the field winding 22 around the magnetic pole piece 21, the magnetic pole of the stator 20 may be a permanent magnet.

Embodiment 2. FIG.
In the first embodiment, the stator 20 is divided into a plurality of blocks. However, the stator 20 can be configured without being divided into a plurality of blocks. In the second embodiment, items that are not particularly described are the same as those in the first embodiment, and the same functions and configurations are described using the same reference numerals.

FIG. 8 is a front view of the stator according to the second embodiment of the present invention (viewed from the direction of the rotation axis). In addition, the arrow shown in the figure indicates the direction of easy magnetization.
The outer portion of the stator 20 has a substantially square frame shape, and two magnetic pole pieces 21 having a substantially crescent shape are opposed to each other on the inner peripheral portion. The stator 20 is formed by laminating a plurality of stator pieces punched from a grain-oriented electrical steel sheet with a press or the like so that their magnetization easy directions are aligned. The easy magnetization direction is the direction in which the pole piece 21 faces.

  In the commutator motor 1 configured as described above, the direction of easy magnetization and the direction of magnetic flux are different in the range corresponding to the blocks 20a, 20b, 20d, and 20e in the first embodiment of the stator 20, and therefore, the brush 6 and the commutator. However, since the stator 20 can be easily manufactured, the manufacturing cost of the commutator motor 1 can be reduced.

  As mentioned above, the vacuum cleaner which has the said effect can be obtained by mounting the brushless motor 1 shown in Embodiment 1 and Embodiment 2 in a vacuum cleaner.

FIG. 3 is a schematic cross-sectional view in the direction parallel to the rotation axis of the commutator motor in the first embodiment. 3 is a front view of the armature in the first embodiment. FIG. FIG. 3 is a front view of the stator in the first embodiment. It is an example of the general hysteresis curve of an electromagnetic steel plate. It is a hysteresis curve which measured the non-oriented silicon steel plate (JFE Steel Co., Ltd. product name "35JN200") which is an example of a non-oriented electrical steel plate by the 25cm Epstein test (JISC2550). It is the hysteresis curve which measured the grain-oriented silicon steel plate (JFE Steel Co., Ltd. product name "27JGSD090") which is an example of a grain-oriented electrical steel plate by the 25-cm Epstein test (JISC2550) by making the easy magnetization direction into a longitudinal direction. It is a characteristic view which shows the relationship between the coercive force Hc [A / m] of an electromagnetic steel plate, and the magnitude | size of the spark which generate | occur | produces between the brush 6-commutator 5. FIG. FIG. 3 is a front view of the stator in the first embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Commutator motor, 2 (2a, 2b) Frame, 3 (3a, 3b) Bearing, 4 Rotating shaft, 5 Commutator, 6 Brush, 7 Brush holder, 10 Armature, 10n Steel plate, 11 Armature core, 12 Electric Child winding, 20 stator, 20a-20f block, 21 pole piece, 21a, 21b block, 22 field winding.

Claims (9)

A stator in which a plurality of steel plates are laminated and a plurality of magnetic poles are formed on the inner periphery, and
An armature winding wound around an armature core configured by laminating a plurality of steel plates, and an armature provided rotatably on the inner peripheral side of the magnetic pole;
A commutator provided on a rotating shaft of the armature and connected to the armature winding;
In a commutator motor comprising a brush that contacts the commutator,
The armature core is composed of a steel plate having a smaller coercive force than a non-oriented electrical steel plate.   The commutator motor according to claim 1, wherein the armature core is composed of a grain-oriented electrical steel sheet. The armature core is
The commutator motor according to claim 2, wherein the directionality steel plates are stacked while being shifted by a predetermined angle in an easy magnetization direction. The predetermined angle is
When the number of laminated grain-oriented electrical steel sheets is n (n is a natural number of 2 or more),
The commutator motor according to claim 3, wherein the commutator motor is 180 ° / n.   The commutator motor according to any one of claims 1 to 4, wherein the stator is made of a steel plate having a smaller coercive force than the non-oriented electrical steel plate. A stator in which a plurality of steel plates are laminated and a plurality of magnetic poles are formed on the inner periphery, and
An armature winding wound around an armature core configured by laminating a plurality of steel plates, and an armature provided rotatably on the inner peripheral side of the magnetic pole;
In a commutator motor comprising a brush that contacts the commutator,
The stator is composed of a steel plate having a smaller coercive force than a non-oriented electrical steel plate.   The commutator motor according to claim 5 or 6, wherein the stator is composed of a grain-oriented electrical steel sheet. The stator is composed of a plurality of divided blocks,
The commutator motor according to claim 7, wherein the stator is configured such that the direction of magnetic flux generated in the block and the easy magnetization direction of the block are the same direction.   An electric vacuum cleaner comprising the commutator motor according to any one of claims 1 to 8.

Images