JP2020058173A - Armature and electric motor - Google Patents

Abstract

To provide an armature and an electric motor, capable of reliably obtaining desired motor characteristics and determining the entire mass with high accuracy while suppressing variations in rotation balance and weight balance.SOLUTION: A plurality of coils 71U to 72W of each phase is formed in one of each of teeth 50 and a predetermined slot 51. The coils 71U to 72W of each phase are laminated on one of the teeth 50 and the predetermined slot 51 along a direction in which the coils are separated from the teeth 50. The number of windings of a winding wire 7 is smaller for the coils 71U to 72W located farther from the teeth 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an armature and an electric motor.

Among the motors, there is a three-phase DC motor with a brush (hereinafter referred to as a brush motor) mounted on a vehicle or the like. The brushed motor includes a cylindrical yoke having a permanent magnet attached to an inner peripheral surface thereof, and an armature rotatably provided radially inside the yoke.
The armature has a rotating shaft, an armature core externally fixed to the rotating shaft, and a commutator externally fixed to the rotating shaft so as to be adjacent to the armature core.

The armature core extends in a radial direction and has a plurality of teeth arranged radially. A dovetail-shaped slot is formed between adjacent teeth in the circumferential direction. A winding is wound around each tooth via these slots. One coil is formed by a plurality of turns. The winding operation of the winding is performed by a winding device.
The commutator has a plurality of segments arranged along the circumferential direction. The ends of the windings are connected to these segments. A brush is slid on each segment. The brush is electrically connected to an external power supply. Then, current is supplied to the windings by applying the power of the external power supply to each segment via the brush.

As a result, a predetermined magnetic field is formed in the armature core, and a magnetic attractive force or a repulsive force is generated between the magnetic field and the permanent magnet. Therefore, the armature rotates.
In addition, as the armature rotates, the segments with which the brush slides are sequentially changed, and the direction of the current supplied to the coil is switched, that is, so-called rectification is performed. This causes the armature to rotate continuously.

Here, the tension applied to the winding wound on the teeth often differs depending on the winding device used. In addition, even if the windings have the same wire diameter, a slight difference in wire diameter often occurs due to a manufacturing error. For this reason, there is a possibility that the rotation balance and the weight balance of the armature may vary.
In order to suppress such variations in the rotational balance and the weight balance of the armature, there is disclosed a technique in which two coils each having a winding wound around a predetermined tooth are arranged. The two coils are stacked along a direction away from the teeth. As a method of winding the windings forming such two coils, a so-called double flyer method is adopted, in which windings are simultaneously drawn out from two flyers existing at point symmetric positions about the rotation axis.

  That is, after winding a coil wound from a first flyer around a predetermined tooth to form a first coil (first coil), a second coil is placed on the first coil. A second coil (second coil) is formed by winding a winding fed from a flyer. That is, a coil can be formed evenly on each tooth by one winding and one flyer. In addition, the second coil from the first coil can be uniformly formed on each tooth. This second coil is also formed by one winding and one flyer. By reducing the number of turns of the windings for forming two coils to half of the predetermined number of turns, a coil having the predetermined number of turns is eventually formed on each tooth. With this configuration, it is possible to suppress variations in the rotational balance and the weight balance of the armature.

JP 2013-090428 A

However, since the second coil is formed on the first coil, even if the number of turns of each winding forming these two coils is the same, the second coil is formed due to the difference in circumference. Winding length becomes long. Therefore, the resistance value of the first coil differs from the resistance value of the second coil, and it may be difficult to obtain desired motor characteristics.
Further, when a double flyer method is adopted as a method of winding the winding, a separate winding is used for each flyer. Even if the windings have the same wire diameter, a slight difference in wire diameter may occur due to a manufacturing error. For this reason, if the double flyer method is adopted, there is a possibility that it is difficult to determine the mass of the armature with high accuracy.

  Accordingly, the present invention provides an armature and an electric motor that can reliably obtain desired motor characteristics while suppressing variations in rotational balance and weight balance, and that can determine the overall mass with high accuracy. I do.

  In order to solve the above problem, an armature according to the present invention includes an armature core having a plurality of teeth arranged in a circumferential direction and a plurality of slots formed between the teeth adjacent in the circumferential direction. A coil formed by winding a winding a predetermined number of times, and a commutator having a plurality of segments to which terminal portions of the windings are connected, in each of the teeth and one of the predetermined slots. A plurality of the coils are formed in each of the teeth and one of the predetermined slots; and a plurality of the coils are formed in the one of the teeth and the predetermined slots by the teeth. The coil is stacked along a direction in which the coils are separated from each other, and the number of turns of the winding is smaller as the coils are positioned further away from the teeth.

In the plurality of stacked coils, the number of turns of the winding is smaller as the coil is located farther from the teeth. Since the circumferential length is increased by the distance from the teeth, the lengths of the windings forming each coil are likely to be the same as a result. Further, since a plurality of coils are formed between each tooth or a predetermined slot, it is easy to suppress variations in the rotational balance and weight balance of the armature. Therefore, desired motor characteristics can be reliably obtained.
Further, as a method of winding the winding, a so-called single flyer method which uses one flyer can be adopted. For this reason, since the same winding can be used as much as possible, the mass of the armature can be determined with high accuracy.

  In the armature according to the present invention, the number of the teeth is an even number, and one of the coils includes the two teeth and the two predetermined slots that are arranged point-symmetrically with respect to a rotation axis of the armature core. Characterized by comprising the winding wound in series between the windings.

  With this configuration, the weight balance of one coil can be reliably improved. For this reason, desired motor characteristics can be obtained more reliably while variations in rotation balance and weight balance are more reliably suppressed.

  In the armature according to the present invention, two of the coils are arranged in each of the teeth and any one of the predetermined slots, and the number of turns of the winding forming the inner coil is the inner number. The number of turns of the windings forming the outer coil disposed on the coil is larger than the number of turns.

  With this configuration, desired motor characteristics can be reliably obtained with a simple structure while suppressing variations in the rotational balance and weight balance of the armature. In addition, the mass of the entire armature can be determined with high accuracy.

The armature according to the present invention is characterized in that each of the windings whose both ends are connected between the predetermined segments has the same length.
In this case, in the electric motor, each of the windings having both ends connected between the predetermined segments may have the same resistance.

  With this configuration, the motor characteristics of the electric motor can be reliably improved.

  The electric motor according to the present invention includes the armature described above, the armature rotatably supported, a cylindrical yoke, a plurality of permanent magnets provided on an inner peripheral surface of the yoke, and a plurality of the segments. And a plurality of brushes slidably contacting the coil to supply a current to the coil.

  With this configuration, it is possible to reliably obtain desired motor characteristics while suppressing variations in the rotation balance and weight balance of the electric motor. Further, the mass of the entire electric motor can be determined with high accuracy.

  The electric motor according to the present invention is characterized in that the permanent magnet has four magnetic poles, the number of teeth is six, and the number of segments is twelve.

  Thus, it can be suitably used for a so-called 4-pole, 6-slot, 12-segment electric motor.

According to the present invention, in the plurality of stacked coils, the number of turns of the winding is smaller as the coil is located farther from the teeth. Since the circumferential length is increased by the distance from the teeth, the lengths of the windings forming each coil are likely to be the same as a result. Further, since a plurality of coils are formed between each tooth or a predetermined slot, it is easy to suppress variations in the rotational balance and weight balance of the armature. Therefore, desired motor characteristics can be reliably obtained.
Further, as a method of winding the winding, a so-called single flyer method which uses one flyer can be adopted. For this reason, since the same winding can be used as much as possible, the mass of the armature can be determined with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which follows the axial direction of the motor with a brush in embodiment of this invention. It is the figure which expanded the permanent magnet, the teeth, the segment, and the coil of each phase in embodiment of this invention. It is an explanatory view of arrangement of a coil of each phase to an armature core in an embodiment of the present invention. 4 is a graph showing a change in a resistance value of a winding according to the embodiment of the present invention.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(Motor with brush)
FIG. 1 is a cross-sectional view of the brushed motor 1 along the axial direction.
The brushed motor 1 is used, for example, as a drive source for electrical components mounted on a vehicle.
As shown in FIG. 1, the brushed motor 1 includes an armature 3 rotatably provided in a substantially bottomed cylindrical yoke 2, and an opening 2 c of the yoke 2 is closed by an end bracket 17. In the following description, the rotation axis direction of the armature 3 will be referred to simply as the axial direction, the rotation direction of the armature 3 will be referred to as the circumferential direction, and the radial direction of the armature 3 orthogonal to the axial direction and the circumferential direction will be referred to simply as the radial direction.

Four permanent magnets 4 are fixed to the inner peripheral surface of the yoke 2 in the circumferential direction. That is, it has four magnetic poles.
The armature 3 includes a rotating shaft 5, an armature core 6 fixed to the rotating shaft 5, coils 71 </ b> U to 72 </ b> W of each phase formed on the armature core 6, and a commutator 13 disposed at one end of the armature core 6. , Is provided. The axis of the rotation shaft 5 matches the rotation axis of the armature 3.

The armature core 6 is formed, for example, by stacking a plurality of ring-shaped metal plates 8 in the axial direction. However, the armature core 6 may be formed by press-molding soft magnetic powder.
Six T-shaped teeth 50 are formed on the outer peripheral portion of the metal plate 8 so as to project radially outward when viewed from the axial direction. Each tooth 50 is arranged at equal intervals along the circumferential direction. By fitting a plurality of metal plates 8 to the outer peripheral surface of the rotating shaft 5, a dovetail-shaped slot 51 is formed between adjacent teeth 50 on the outer periphery of the armature core 6. The slots 51 extend in the axial direction, and are formed at equal intervals along the circumferential direction. The winding 7 is wound around the teeth 50 through these slots 51. The wound winding 7 forms coils 71U to 72W of each phase (details will be described later).

  The commutator 13 is fitted and fixed to the outer peripheral surface of one end of the rotating shaft 5. On the outer peripheral surface of the commutator 13, twelve segments 14 made of a conductive material are attached. As described above, the brushed motor 1 of the present embodiment has four permanent magnets 4 (the number of magnetic poles is four), six slots 51 (six teeth 50), and twelve segments 14. This is a so-called 4-pole, 6-slot, 12-segment (double segment) motor.

  The segments 14 are formed of plate-shaped metal pieces that are long in the axial direction, and are fixed in parallel at equal intervals along the circumferential direction while being insulated from each other. A riser 15 is formed integrally with the segment 14 at the end of the armature core 6 side of each segment 14 so as to be folded back toward the outer diameter side. The winding 7 wound around the teeth 50 is wound around the riser 15, and is fixed by, for example, fusing. As a result, the segment 14 and the corresponding winding 7 are electrically connected.

  The windings 7 are connected so as to short-circuit two predetermined segments 14 among the segments 14, that is, two segments 14 having the same potential. Do). The winding 7 that short-circuits the two segments 14 having the same potential functions as a pressure equalizing line (connection line) 52. These pressure equalizing lines 52 are also looped around the riser 15 of the predetermined segment 14 and are fixed by, for example, fusing.

  The other end of the rotating shaft 5 is rotatably supported by a bearing 12 in a boss protruding from the bottom 2 b of the yoke 2. An end bracket 17 is provided at an end of the yoke 2 on the opening 2c side. A holder stay 20 is mounted inside the end bracket 17. For example, a pair of brush holders 21 are formed on the holder stay 20 at intervals of 90 ° in the circumferential direction. The brush holders 21 are provided with brushes 22 which are urged through springs 23 so as to be able to come and go.

  Each brush 22 is electrically connected to an external power supply via the pigtail 16. Each brush 22 is classified into a positive brush and a negative brush. The tips of the brushes 22 are urged by the springs 23 and are in sliding contact with the commutator 13. The brush 22 is electrically connected to an external power supply (not shown). As a result, electric power from an external power supply is supplied to the commutator 13 via the brush 22.

(Coil forming method)
Next, a method of forming the coils 71U to 72W of each phase will be described with reference to FIGS.
FIG. 2 is a developed view of the permanent magnet 4, the teeth 50 of the armature 3, the segments 14, and the coils 71U to 72W (equalizing lines 52) of each phase. It corresponds to the slot 51. FIG. 3 is an explanatory diagram of the arrangement of the coils 71U to 72W of each phase with respect to the armature core 6. In FIG. 3, the armature core 6 is viewed from the axial direction.

  Here, in winding the winding 7 around each tooth 50 and each segment 14, as a winding device to be used, a flyer that draws out the winding 7 (neither the winding device nor the flyer is shown). A winding device having one is used. That is, coils 71U to 72W of each phase are formed in each tooth 50 and each segment 14 by a single flyer method.

As shown in FIG. 2, the armature 3 has a three-phase (U-phase, V-phase, W-phase) structure, and each tooth 50 is assigned in the circumferential direction in the order of U-phase, V-phase, and W-phase. I have. That is, the teeth 50 of the same phase are arranged point-symmetrically about the rotation axis 5.
In the following description, the phases and numbers assigned to the teeth 50 will be sequentially assigned, and the segments 14 will be sequentially numbered in the circumferential direction. In FIG. 2, each segment 14 is numbered so that the first segment 14 is located near the U1 (1) tooth 50, but the number is not limited thereto. Can be set arbitrarily.

The winding 7 is wound around each tooth 50 by a concentrated winding method. The winding 7 is wound around the riser 15 of the seventh segment 14 at the winding start end 7a and is connected thereto. Subsequently, the winding 7 is routed in one rotational direction of the armature 3 (the rotating shaft 5) (to the right in FIG. 2, in the following description, simply referred to as one direction). Thereafter, the winding 7 is wound around and connected to the riser 15 of the first segment 14, and forms a pressure equalizing line 52 between the seventh and first segments 14.
Subsequently, the winding 7 is wound around the U1 (1) tooth 50 in the forward direction (clockwise direction in FIG. 2) after being wound in one direction from the first segment 14, and is wound in the first U-phase. A forward coil 171Ua is formed.

  Subsequently, the winding 7 is rotated from the U1 (1) tooth 50 in a direction opposite to the one direction (the other direction of the rotation direction of the armature 3 (the rotating shaft 5), the left direction in FIG. 2, and hereinafter simply referred to as the other direction). ). Thereafter, the winding 7 is wound in the forward direction around the U2 (4) th tooth 50 to form a second U-phase forward coil 172Ua. The first U-phase forward coil 171Ua and the second U-phase forward coil 172Ua are arranged point-symmetrically about the rotating shaft 5, and constitute a U-phase first coil 71U connected in series to each other.

Subsequently, the winding 7 is routed from the U2 (4) th tooth 50 in the other direction. Thereafter, the winding 7 is wound around and connected to the riser 15 of the second segment 14.
As described above, the terminal portion of the winding 7 forming the U-phase first coil 71U including the first U-phase forward coil 171Ua and the second U-phase forward coil 172Ua is connected to the first and second segments 14.

  Subsequently, the winding 7 is wound in one direction from the second segment 14. Thereafter, the winding 7 is wound around and connected to the riser 15 of the eighth segment 14, and forms a pressure equalizing line 52 between the second and eighth segments 14.

Subsequently, the winding 7 is wound in one direction from the eighth segment 14. Thereafter, the winding 7 is wound around the W1 (3) th tooth 50 in a reverse direction (counterclockwise direction in FIG. 2) opposite to the forward direction to form a first W-phase reverse coil 171Wb.
Subsequently, the winding 7 is wound in one direction from the W1 (3) th tooth 50. Thereafter, the winding 7 is wound in the reverse direction around the W2 (6) th tooth 50 to form a second W-phase reverse coil 172Wb. The first W-phase reverse coil 171Wb and the second W-phase reverse coil 172Wb are arranged point-symmetrically about the rotating shaft 5, and constitute a W-phase first coil 71W connected in series to each other.

Subsequently, the winding 7 is wound in one direction from the W2 (6) th tooth 50. Thereafter, the winding 7 is wound around and connected to the riser 15 of the third segment 14.
As described above, the terminal portion of the winding 7 forming the W-phase first coil 71W including the first W-phase reverse coil 171Wb and the second W-phase reverse coil 172Wb is connected to the eighth and third segments 14.

  Subsequently, the winding 7 is routed in one direction from the third segment 14. Thereafter, the winding 7 is wound around and connected to the riser 15 of the ninth segment 14, and forms a pressure equalizing line 52 between the third and ninth segments 14.

Subsequently, the winding 7 is wound in one direction from the ninth segment 14. After that, the winding 7 is wound around the V2 (5) th tooth 50 in the forward direction to form the second V-phase forward coil 172Va.
Subsequently, the winding 7 is routed in the other direction from the V2 (5) th tooth 50. Thereafter, the winding 7 is wound around the V1 (2) th tooth 50 in the forward direction to form a first V-phase forward coil 171Va. The second V-phase forward coil 172Va and the first V-phase forward coil 171Va are arranged point-symmetrically with respect to the rotation axis 5, and constitute a V-phase first coil 71V connected in series to each other.

  Subsequently, the winding 7 is drawn in one direction from the V1 (2) th tooth 50. Thereafter, the winding 7 is wound around and connected to the riser 15 of the tenth segment 14. As described above, the terminal portion of the winding 7 forming the V-phase first coil 71V including the second V-phase forward coil 172Va and the first V-phase forward coil 171Va is connected to the ninth and tenth segments 14.

  Subsequently, the winding 7 is wound in one direction from the tenth segment 14. Thereafter, the winding 7 is wound around and connected to the riser 15 of the fourth segment 14 to form a pressure equalizing line 52 between the tenth and fourth segments 14.

Subsequently, the winding 7 is wound in one direction from the fourth segment 14. Thereafter, the winding 7 is wound around the U1 (1) th tooth 50 in the reverse direction to form a first U-phase reverse coil 171Ub.
Subsequently, the winding 7 is wound in one direction from the U1 (1) th tooth 50. Thereafter, the winding 7 is wound around the U2 (4) th tooth 50 in the reverse direction to form a second U-phase reverse coil 172Ub.

  The first U-phase reverse coil 171Ub and the second U-phase reverse coil 172Ub are arranged point-symmetrically about the rotation shaft 5, and constitute a U-phase second coil 72U connected in series to each other. The U-phase second coil 72U (first U-phase reverse coil 171Ub, second U-phase reverse coil 172Ub) is a U-phase first coil 71U (first U-phase forward coil 171Ua, second U-phase forward coil 172Ua). ) Is formed by winding the winding 7. For this reason, as shown in detail in FIG. 3, the U-phase second coil 72U is arranged so as to be stacked along the direction away from the teeth 50 with respect to the U-phase first coil 71U.

  Returning to FIG. 2, subsequently, the winding 7 is wound in one direction from the U2 (4) th tooth 50. Thereafter, the winding 7 is wound around and connected to the riser 15 of the eleventh segment 14. As described above, the terminal portion of the winding 7 forming the U-phase second coil 72U including the first U-phase reverse coil 171Ub and the second U-phase reverse coil 172Ub is connected to the fourth and eleventh segments 14.

  Subsequently, the winding 7 is wound in one direction from the eleventh segment 14. Thereafter, the winding 7 is wound around and connected to the riser 15 of the fifth segment 14, and forms a pressure equalizing line 52 between the eleventh and fifth segments 14.

Subsequently, the winding 7 is wound in one direction from the fifth segment 14. Thereafter, the winding 7 is wound around the W1 (3) th tooth 50 in the forward direction to form the first W-phase forward coil 171Wa.
Subsequently, the winding 7 is routed from the W1 (3) th tooth 50 in the other direction. Thereafter, the second W-phase forward coil 172 Wa is formed by being wound around the W2 (6) th tooth 50 in the forward direction.

  The first W-phase forward coil 171Wa and the second W-phase forward coil 172Wa are arranged point-symmetrically about the rotating shaft 5, and constitute a W-phase second coil 72W connected in series to each other. The W-phase second coil 72W (first W-phase forward coil 171Wa, second W-phase forward coil 172Wa) is a W-phase first coil 71W (first W-phase reverse coil 171Wb, second W-phase reverse coil 172Wb) formed in advance. ) Is formed by winding the winding 7. For this reason, as shown in detail in FIG. 3, the W-phase second coil 72W is arranged so as to be stacked along the direction away from the teeth 50 with respect to the W-phase first coil 71W.

  Returning to FIG. 2, subsequently, the winding 7 is routed in the other direction from the W2 (6) th tooth 50. Thereafter, the winding 7 is wound around and connected to the riser 15 of the sixth segment 14. As described above, the terminal portion of the winding 7 forming the W-phase second coil 72 </ b> W including the first W-phase forward coil 171 Wa and the second W-phase forward coil 172 Wa is connected to the fifth and sixth segments 14.

  Subsequently, the winding 7 is wound in one direction from the sixth segment 14. Thereafter, the winding 7 is wound around and connected to the riser 15 of the twelfth segment 14, and forms a pressure equalizing line 52 between the sixth and twelfth segments 14.

Subsequently, the winding 7 is wound in one direction from the twelfth segment 14. Thereafter, the second V-phase reverse coil 172Vb is formed by being wound around the V2 (5) th tooth 50 in the reverse direction.
Subsequently, the winding 7 is routed in one direction from the V2 (5) th tooth 50. Thereafter, the winding 7 is wound around the V1 (2) th tooth 50 in the reverse direction to form the first V-phase reverse coil 171Vb.

  The second V-phase reverse coil 172Vb and the first V-phase reverse coil 171Vb are arranged point-symmetrically with respect to the rotation axis 5 and constitute a V-phase second coil 72V connected in series to each other. The V-phase second coil 72V (second V-phase reverse coil 172Vb, first V-phase reverse coil 171Vb) is a V-phase first coil 71V (second V-phase forward coil 172Va, first V-phase forward coil 171Va) formed in advance. ) Is formed by winding the winding 7. For this reason, as shown in detail in FIG. 3, the V-phase second coil 72V is arranged so as to be stacked along the direction away from the teeth 50 with respect to the V-phase first coil 71V.

  Returning to FIG. 2, subsequently, the winding 7 is routed in one direction from the V1 (2) th tooth 50. Thereafter, the winding 7 is wound around the riser 15 of the seventh segment 14 at the winding end 7 b and connected. In this way, the terminal of the winding 7 forming the V-phase second coil 72V composed of the second V-phase reverse coil 172Vb and the first V-phase reverse coil 171Vb is connected to the twelfth and seventh segments 14. This completes the winding operation of the winding 7 fed from the first flyer.

(Number of turns of winding)
Next, the number of turns of the windings 7 forming the first coils 71U, 71V, 71W and the second coils 72U, 72V, 72W of each phase will be described in detail.
The first U-phase forward coil 171Ua, the second U-phase forward coil 172Ua, the second V-phase forward coil 172Va, the first V-phase forward coil 171Va, the first W-phase reverse coil 171Wb and the first coils 71U, 71V, 71W of each phase, and The second W-phase reverse coil 172Wb has the same number of turns of the winding 7. Since the number of turns of these windings 7 is all the same, the number of turns is defined as the number of turns N1 of the first coils 71U, 71V, 71W of each phase.

  On the other hand, the first U-phase reverse coil 171Ub, the second U-phase reverse coil 172Ub, the second V-phase reverse coil 172Vb, the first V-phase reverse coil 171Vb, and the first W-phase forward coil 171Wa constituting the second coils 72U, 72V, 72W of each phase. , And the second W-phase forward coil 172 Wa have the same number of turns of the winding 7. Since the number of turns of these windings 7 is all the same, the number of turns is defined as the number of turns N2 of the second coils 72U, 72V, 72W of each phase.

  Here, the first coils 71U, 71V, and 71W of each phase are arranged such that the second coils 72U, 72V, and 72W of each phase are stacked in a direction away from the teeth 50. For this reason, the second coil of each phase is arranged around the teeth 50 with respect to the circumference when the winding 7 forming the first coils 71U, 71V, 71W of each phase is wound once around the teeth 50. When the winding 7 forming 72U, 72V, 72W is wound once, the circumference becomes longer.

  Therefore, in the present embodiment, the number of turns N1 of the first coils 71U, 71V, 71W of each phase is set to be larger than the number of turns N2 of the second coils 72U, 72V, 72W of each phase. For example, when the predetermined number of turns of the winding 7 for one tooth 50 is 21 times, the number of turns N1 of the first coils 71U, 71V, 71W of each phase is set to 11 times. The number of turns N2 of the second coils 72U, 72V, 72W of each phase is set to ten.

  With this configuration, the total length of the windings 7 forming the first coils 71U, 71V, 71W of each phase, the total length of the windings 7 forming the second coils 72U, 72V, 72W of each phase, Are almost the same. As a result, the resistance of the winding 7 forming the first coils 71U, 71V, 71W of each phase is substantially the same as the resistance of the winding 7 forming the second coils 72U, 72V, 72W of each phase. .

FIG. 4 shows a change in the resistance value of the winding 7 when the vertical axis is the resistance value [Ω] of the winding 7 and the horizontal axis is the position of the segment 14 for measuring the resistance value of the winding 7. It is a graph. In FIG. 4, two numbers (for example, “1-2”) on the horizontal axis indicate numbers assigned to the segments 14 respectively. In FIG. 4, reference symbol IN denotes each of the first coils 71 </ b> U, 71 </ b> V, 71 </ b> W of each phase and the second coils 72 </ b> U, 72 </ b> V, 72 </ b> W of each phase that is closer to the teeth 50 (located inside). The first coils 71U, 71V, 71W of the phase are shown. In FIG. 4, reference symbol OUT indicates second coils 72 </ b> U, 72 </ b> V, 72 </ b> W of each phase which are more distant from teeth 50 than first coils 71 </ b> U, 71 </ b> V, 71 </ b> W of each phase.
As shown in FIG. 4, at each measurement position of the segment 14, it can be confirmed that the resistance of the winding 7 is substantially equal.

  Thus, in the above-described embodiment, the first coils 71U, 71V, 71W and the second coils 72U, 72V, 72W of the corresponding phases are stacked on each tooth 50, respectively. In these two coils 71U to 72W, the number of turns of the winding 7 decreases as the distance from the teeth 50 increases. That is, the second coil 72U of each phase which is farther from the teeth 50 than the first coils 71U, 71V, 71W than the number of turns of the winding 7 forming the first coils 71U, 71V, 71W of each phase. , 72V, 72W, the number of turns of the winding 7 is small. Therefore, the length and resistance of each winding 7 forming each of the coils 71U to 72W can be made substantially the same. Therefore, desired motor characteristics of the brushed motor 1 can be reliably obtained while suppressing variations in the rotation balance and weight balance of the armature 3.

In addition, a single flyer method can be adopted as a method of winding the winding 7. For this reason, since the same winding 7 can be used as much as possible, the mass of the armature 3 can be determined with high accuracy.
The brushed motor 1 of the above embodiment is a so-called 4-pole, 6-slot, 12-segment (double segment) motor, and the number of teeth 50 is an even number. The teeth 50 having the same phase are arranged point-symmetrically about the rotation axis 5. The windings 7 are wound continuously (in series) around the teeth 50 of the same phase to form the coils 71U to 72W. Therefore, the weight balance of each of the coils 71U to 72W can be reliably improved. Therefore, it is possible to provide the brushed motor 1 that can more reliably obtain desired motor characteristics while more reliably suppressing variations in rotation balance and weight balance.

Note that the present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, a case has been described in which the brushed motor 1 is used as a drive source of an electrical component (for example, a power window) mounted on a vehicle. However, the present invention is not limited to this, and the brushed motor 1 can be employed for driving various devices.

In the above-described embodiment, the brushed motor 1 has four permanent magnets 4 (the number of magnetic poles is four), six slots 51 (six teeth 50), and twelve segments 14. The case of a so-called 4-pole, 6-slot, 12-segment (double segment) motor has been described. Furthermore, the case where two teeth 71U to 72W of the first coil 71U to 71W and the second coil 72U to 72W of the corresponding phase are formed in each tooth 50 has been described. In addition, in the above-described embodiment, for example, when the predetermined number of turns of the winding 7 for one tooth 50 is 21 times, the number of turns N1 of the first coils 71U, 71V, and 71W of each phase is set to 11 times. The case of setting has been described. Furthermore, the case where the number of turns N2 of the second coils 72U, 72V, 72W of each phase is set to 10 has been described. The case where the lengths and the resistances of the windings 7 forming the coils 71U to 72W are made substantially the same has been described.
However, the motor is not limited to a motor having 4 poles, 6 slots, and 12 segments. The method of forming the coils 71U to 72W of the above-described embodiment can be adopted for various motors in which a plurality of coils of two or more layers are stacked on each tooth 50 along a direction away from the teeth 50. . It is desirable that the number of the teeth 50 be an even number. The coils stacked on each of the teeth 50 need only have a smaller number of turns of the winding 7 at a position farther from the teeth 50. The number of turns of each coil is not limited to the above number of turns. The number of turns is set so that the length of each winding 7 forming each coil is the same. Or the number of turns may be set so that is the same.

  In the above-described embodiment, the case where the winding 7 is wound around each tooth 50 by the concentrated winding method has been described. However, the present invention is not limited to this, and the coil 71U of the above-described embodiment may be used in a so-called lap winding method or a wave winding method in which the winding 7 is wound between predetermined slots 51 over a plurality of teeth 50. ~ 72W forming method can be adopted.

DESCRIPTION OF SYMBOLS 1 ... Brush motor (electric motor), 2 ... Yoke, 3 ... Armature, 4 ... Permanent magnet, 5 ... Rotary shaft, 6 ... Armature core, 7 ... Winding, 7a ... Winding start end (terminal part), 7b ... End of winding (end part), 13: segment, 14: commutator, 22: brush, 50: teeth, 51: slot, 52: equalizing line, 71U: first coil (coil) of U phase, 71V: V phase , A first coil (coil) of 71W... A second coil (coil) of 72U... U phase, a second coil (coil) of 72V. 2 coils (coils), 171Ua, 271Ua: first U-phase forward coil, 171Ub, 271Ub: first U-phase reverse coil, 171Va, 271Va: first V-phase forward coil, 171Vb, 271Vb: first V-phase reverse coil, 1 1 Wa, 271 Wa: first W phase forward coil, 171 Wb, 271 Wb: first W phase reverse coil, 172 Ua, 272 Ua: second U phase forward coil, 172 Ub, 272 Ub: second U phase reverse coil, 172 Va, 272 Va: second V phase forward coil, 172 Vb, 272 Vb: second V-phase reverse coil, 172 Wa, 272 Wa: second W-phase forward coil, 172 Wb, 272 Wb: second W-phase reverse coil, N1, N2 ... number of turns

Claims (7)

An armature core having a plurality of teeth arranged side by side in the circumferential direction, and a plurality of slots formed between the teeth adjacent in the circumferential direction;
A coil formed by winding a predetermined number of times on each of the teeth and any one of the predetermined slots;
A commutator having a plurality of segments to which a terminal portion of the winding is connected;
With
A plurality of the coils are formed in each of the teeth and any one of the predetermined slots,
The plurality of coils are stacked on one of the teeth and one of the predetermined slots along a direction away from the teeth. An armature characterized by a small number of times. The number of the teeth is an even number,
One of the coils is composed of the two teeth that are arranged point-symmetrically about the rotation axis of the armature core, and the winding wound in series on one of two predetermined slots. The armature according to claim 1, wherein the armature comprises: In each of the teeth and any one of the predetermined slots, two coils are arranged,
The number of turns of the winding forming the inner coil is greater than the number of turns of the winding forming the outer coil disposed on the inner coil. An armature according to claim 2. The armature according to any one of claims 1 to 3, wherein each of the windings having both ends connected between the predetermined segments has the same length. . The armature according to any one of claims 1 to 4, wherein each of the windings having both ends connected between the predetermined segments has the same resistance. The armature according to any one of claims 1 to 5,
Rotatably supporting the armature, a cylindrical yoke,
A plurality of permanent magnets provided on the inner peripheral surface of the yoke,
A plurality of brushes that are in sliding contact with the plurality of segments and supply current to the coil;
An electric motor comprising: The electric motor according to claim 6, wherein the number of magnetic poles of the permanent magnet is four, the number of the teeth is six, and the number of the segments is twelve.

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