WO2012102019A1

WO2012102019A1 - Motor

Info

Publication number: WO2012102019A1
Application number: PCT/JP2012/000422
Authority: WO
Inventors: Yusuke Makino; Takahiro Hiwa; Shohei OSUGA
Original assignee: Nidec Corp
Current assignee: Nidec Corp
Priority date: 2011-01-28
Filing date: 2012-01-24
Publication date: 2012-08-02
Anticipated expiration: 2013-07-28
Also published as: DE112012000591T5; JP5928452B2; CN103283131B; US20130249339A1; US9431862B2; JP2014504128A; CN103283131A

Abstract

[Means for Resolution] A winding structure which is disposed over an armature and a commutator is provided. The winding structure includes an equalizer. The equalizer includes a going portion and a return portion which are wound across one group of teeth through a slot and connect between two identical segments. In a case where the number which becomes the integer is given as the expansion value among values which are integer multiples of the value which is acquired by dividing the number of the slots by the number of pole pairs, when one group of the teeth having the same number as the expansion value is given as an element teeth group, the going portion and the return portion are wound across the element teeth group through the slots positioned at both sides of the element teeth group.

Description

MOTOR

The present invention relates to a motor with a brush, and particularly, to an equalizer structure.

For example, an equalizer structure is disclosed in PTL 1. In PTL 1, the equalizer is wound around a slot of an armature core and connects commutator pieces having the same potential.

In recent years, advances have been made regarding the miniaturization of a motor with a brush. In a small-sized motor with a brush, a concentrated winding structure capable of decreasing a height in an axial direction is adapted. However, in the concentrated winding structure, in general, there is a tendency that the number of the magnetic poles of magnets or the number of the brushes is increased. Taking into consideration the costs of the members, or the sound characteristics, and the like, it is preferable that the number of the brushes is decreased. However, if the number of the brushes is decreased, the current capacity of the equalizer becomes a problem.

This is explained with reference to Fig. 1. In Fig. 1, the reference numeral 101 indicates brushes, 102 indicates segments, 103 indicates coils, and 104 indicates an equalizer. For example, as shown in Fig. 1A, in a case where the brushes 101 directly contact the segments 102 to which the coils 103 supplied with current are connected, even though a plurality of coils 103 is connected to the segments 102 in parallel, a current can be supplied to each coil 103 without difficulty.

However, as shown in Fig. 1B, in a case where the equalizer 104 is used while the number of the brushes is decreased, the total capacity of the current to be supplied to each coil 103 flows to the equalizer. Thereby, if the current capacity of the equalizer 104 is insufficient, there is a concern that the equalizer 104 may be blown out. In respect to this, for example, the following two measures are considered.

(1) As the coils and the equalizer, different conducting wires are used, and diameter of the equalizer is greater than that of the coil.
(2) As the coils and the equalizer, the same conducting wire is used, and the diameter of the equalizer and the diameter of the coils are greater.

However, in measure (1), the connection operation between the coils and the equalizer is increased, whereby there are problems in that an increase in the costs or a decrease in the productivity occurs. In measure (2), the winding is difficult if the diameter of the conducting wire of the coil is increased, and there is a problem in that a decrease in the productivity occurs.

Thus, as a measure with respect to the problems, it is considered that a plurality of lines of equalizers is made. Regarding this measure, in paragraph [0031] of PTL 2, a structure is disclosed in which two points of segments having the same potential are connected by a plurality of equalizers. Moreover, also in paragraph [0012] of PTL 1, a structure is disclosed in which two equalizers are wound around between commutator pieces.

JP-A2002-186210 JP-A2000-60074

However, as in PTL 1 or PTL 2, if the segments having the same potential are connected by the plurality of equalizers, a loop circuit is formed between the equalizers. In addition, if the equalizers are wound around an armature core, an induced voltage is generated in the equalizers.

If the induced voltage is generated in the equalizers, circulating short-circuit current is generated in the loop circuit, and a decrease in motor efficiency occurs.

Therefore, an object of the present invention is to provide a motor capable of suppressing occurrence of the short-circuit current even though segments having the same potential are connected by a plurality of equalizers.

A motor according to an exemplary aspect of the present invention includes an armature, a commutator that has a plurality of segments and a shaft that is rotated around a central axis along with the armature and the commutator. In addition, the motor of the present invention includes a magnet, a brush, and a winding structure. The magnet is disposed around the armature, and an N pole and an S pole are alternatively arranged in a circumferential direction. The brush is disposed around the commutator and makes sliding contact with the segment. The winding structure is disposed over the armature and the commutator.

The armature includes a plurality of coils and an armature core that is fixed to the shaft. The armature core includes a plurality of teeth that are radially extended in a radial direction and a plurality of slots that are disposed between the teeth and extended in an axial direction. The winding structure includes a coil winding wire constituting the coil and a leader line that connects between the coil and the segment. In addition, the winding structure includes a connecting wire that connects between two coils and an equalizer that connects between two segments. The equalizer is hooked to the tooth through the slot. In addition, the equalizer includes a going portion and a return portion which connect between two of the identical segments.

In addition, the number which becomes the integer is given as the expansion value among values which are integer multiples of the value which is acquired by dividing the number of the slots by the number of pole pairs constituted by the N pole and the S pole. In this case, when one group of the teeth, which is arranged so as to be continued in the circumferential direction and has the same number as the expansion value, is given as an element teeth group, the going portion and the return portion are hooked to the element teeth group through the slot which is positioned at both sides of the element teeth group.

In addition, in a motor according to an exemplary aspect of the present invention, the total number of the going portions and the return portions is even, and each of the going portions and the return portions may be hooked to the same teeth through the same slot.

According to the motor according to an exemplary aspect of the present invention, since the same conducting wire as the coil or the like is used as the conducting wire of the equalizer, the capacity of the equalizer can be secured. In addition, the occurrence of short-circuit current can be suppressed.
The above and other features, elements, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

Figs. 1A and 1B are diagrams for explaining relationship between number of brushes and capacity of an equalizer. Fig. 2 is a schematic cross-sectional diagram of a motor of the present embodiment. Fig. 3 is a schematic cross-sectional diagram taken along a line I-I of Fig. 2. Fig. 4 is a schematic plan diagram when viewing from the direction of an arrow II of Fig. 2 in a state of removing a back cover. Fig. 5 is a diagram showing a position relationship between teeth or the like and segments. Fig. 6 is a conceptual diagram showing an example of a winding structure. Fig. 7A is a diagram showing a winding order of part (1) in Fig. 6. Fig. 7B is a diagram showing a winding order of part (6) in Fig. 6. Fig. 8 is a diagram for explaining a first winding structure. Fig. 9 is a diagram for explaining a second winding structure. Fig. 10 is a diagram showing a basic configuration of an equalizer of embodiment 1. Fig. 11 is a diagram showing a basic configuration of an equalizer of embodiment 2. Fig. 12 is a diagram showing a basic configuration of an equalizer of a comparative example.[Fig. 13]Fig. 13 is a graph showing results of confirmation tests.

Examples

Hereinafter, embodiments of the present invention will be explained in detail with reference to drawings. However, the following explanation is merely exemplary in nature, and the present invention, the applied objects, or the uses are not limited.

Figs. 2 to 4 show a motor of the present embodiment. The motor is a DC motor and is constituted of a shaft 1, an armature 2, a magnet 3, a commutator 4, a brush 5, a housing 6, or the like. The components of the shaft 1 and the like are accommodated in the housing 6. A winding structure 50 which is constituted of conducting wires 12 is disposed at a portion which is ranged from the armature 2 to the commutator 4.

The winding structure 50 includes a coil winding wire 51 constituting the coil 10, and a leader line 52 which connects between the coil 10 and a segment 15. In addition, the winding structure 50 includes a connecting wire 53 which connects between two coils 10, and an equalizer 54 which connects between two segments 15. The winding structure 50, particularly, the equalizer 54 will be separately described in detail hereinafter.

As shown in Fig. 2, the housing 6 includes a substantially cylindrical case 6a in which the one end is opened, and a back cover 6b which covers an opening of the case 6a.

Bearing portions

7a and 7b are provided in the center portion in the axial direction side in each of the case 6a and the back cover 6b. A shaft hole is formed at the bearing portion 7a.

The shaft 1 is rotatably supported to the housing 6 via the bearing

portions

7a and 7b. Thereby, the shaft 1 is rotated about a rotating shaft J. The one end of the shaft 1 protrudes outside the housing 6 through the shaft hole. The armature 2 and the commutator 4 are fixed to the shaft 1.

In addition, for the explanation, the direction in which the rotating shaft J is extended is referred to as an "axial direction", the direction which is perpendicular to or approximately perpendicular to the axial direction J is referred to as a "radial direction", and the rotation direction of the rotating shaft J is referred to as a "circumferential direction".

Also as shown in Fig. 3, the armature 2 includes an armature core 2a, the coil 10, and an insulator (not shown) having insulation properties. The armature core 2a is formed by laminating metal plates in the axial direction. The insulator is mounted on the armature core 2a and insulates the armature core 2a and the conducting wire 12.

The armature core 2a includes a center core 8 which is fixed at the intermediate portion in the axial direction of the shaft 1. In addition, the armature core 2a includes a plurality of teeth 9 which are radially extended while having substantially regular intervals from the center core 8 to the outside in the radial direction. As a result, a slot 11 which is extended in the axial direction is formed between two teeth 9 which are adjacent to each other. Accordingly, the armature core 2a includes a plurality of slots 11. In addition, in the present embodiment, number of the teeth 9 and number of the slots 11 are 12 respectively.

The coil 10 is formed through a so-called concentrated winding which winds the conducting wire 12 for each tooth 9. The portion of the conducting wire 12 corresponds to the coil winding wire 51. Specifically, the coil 10 is formed by winding the conducting wire 12 around each tooth 9 while passing the conducting wire 12 through each slot 11 which is positioned at both sides in the circumferential direction of the tooth 9 which is an object. Accordingly, the armature 2 includes a plurality of coils 10. In the present embodiment, the number of the coils 10 is 12.

The magnet 3 is annularly disposed around the armature 2. The magnet 3 is fixed to the inner peripheral surface of the case 6a and faces the outer peripheral surface of the armature 2 so as to be separated with a slight gap. The magnet 3 includes magnetic poles 3a which are constituted of a plurality of N poles and a plurality of S poles. In the present embodiment, the number of the magnetic poles is 8. Each magnetic pole 3a is disposed so that the N poles and the S poles are alternatively provided in the circumferential direction. Accordingly, a plurality of pole pairs 3b which is constituted of the N poles and the S poles is provided in the magnet 3. In the present embodiment, the number of the pole pairs is 4. In addition, the magnet 3 may be constituted of a plurality of magnets 3. Moreover, the magnet 3 may be constituted by polarizing a single magnetic body.

The commutator 4 is adjacent to the armature 2 and fixed to the other end of the shaft 1. The commutator 4 includes a plurality of segments 15 at the outer peripheral surface. In the present embodiment, the number of the segments 15 is 24, and the number of the segments 15 is two times of the number of the slots 11. The segment 15 is a metal member which is a plate-like band extended in the axial direction. Each segment 15 is disposed so as to be continued in the circumferential direction in a state of being insulated from each other.

A hook portion 15a is provided at the end of the armature 2 side of each segment 15. A conducting wire 12 which is drawn out from the coil 10 is hooked to the hook portion 15a. By welding the conducting wire 12 which is hooked to the hook portion 15a, each segment 15 is electrically connected to the coil 10.

As shown in Fig. 4, the brush 5 is mounted on a brush plate 16. The brush plate 16 is a disk-shaped member. The brush plate 16 is disposed in the housing 6 in a state of being opposite to the inner surface of the housing cover 6b in the axial direction. A circular hole 16a in which the diameter is greater than the outer diameter of the commutator 4 is formed so as to be opened in the center portion of the brush plate 16. The commutator 4 is disposed in the inner side of the circular hole 16a.

The brush 5 is constituted of two positive pole brushes 5a and two negative pole brushes 5b. Each

brush

5a, 5b is connected to a control device (not shown) or the like via a connecting terminal 17. Each

brush

5a, 5b is disposed around the commutator 4. Each

brush

5a, 5b is pressed to the commutator 4 side from the outside in the radial direction by a spring 5c.

Accordingly, each

brush

5a, 5b always contacts some of the segments 15. According to the rotation of the commutator 4, each

brush

5a, 5b periodically makes sliding contact with each segment 15. As a result, current is periodically supplied from the control device or the like to a predetermined coil 10 according to a predetermined order via the brush 5, the segment 15, and winding structure 50.

The winding structure 50 is formed by using a single conducting wire 12. That is, the coil winding wire 51, the leader line 52, the connecting wire 53, and the equalizer 54 are a single continuous conducting wire. Specifically, through a dedicated winding device, the conducting wire 12 and a predetermined segment 15 are electrically connected to each other while the conducting wire 12 is hooked to the hook portion 15a of the predetermined segment 15. Thereafter, the conducting wire 12 is wound around a predetermined tooth 9 and the winding structure 50 is formed. That is, a plurality of coils 10 is formed by a single conducting wire 12. The leader line 52 which connects between the coil 10 and the segment 15, the connecting wire 53 which connects between two coils 10, and an equalizer 54 which connects between two segments 15 are present between the coils 10.

In this way, since the winding structure 50 is formed by continuously winding a single conducting wire 12, the winding operation is easily performed and the productivity is improved.

The winding structure 50 will be explained in detail based on the disposition of the teeth 9 and the segments 15 shown in Fig. 5. For convenience of explanation, as shown in Fig. 5, numbers are given to each tooth 9 and the coils 10 or the like are distinguished.

Numbers of 1 to 12 from a predetermined tooth 9 in a clockwise direction (CW) are given to each tooth 9 in order, and each tooth 9 is distinguished. Similarly, each coil 10 is also distinguished by the same number as that of the tooth 9 on which the coil 10 is formed. Moreover, each segment 15 is distinguished by being denoted with the numbers of 1 to 24 from a predetermined segment 15 in the vicinity of the tooth 9 denoted with No. 1 in order in a clockwise direction (CW) in the same manner as the tooth 9.

Fig. 6 is a conceptual diagram showing an example of the winding structure 50. Parts (1) to (6) of Fig. 6 simply represent the winding structure 50 in which the winding starts from No. 1 segment 15 and ends at No. 7 segment 15. Fig. 7A shows the winding order in part (1) in Fig. 6. Fig. 7B shows the winding order in part (6) in Fig. 6.

As shown in Fig. 6 or 7A, first, the conducting wire 12 having No. 1 segment 15 as the winding start terminal is led out to the side (hereinafter, referred to as the "tooth 9 side") opposite to the commutator 4 in the tooth 9 through the slot 11 between No. 12 tooth 9 and No. 1 tooth 9. Subsequently, the conducting wire 12 is led out to the commutator 4 side in the tooth 9 through the slot 11 between No. 3 tooth 9 and No. 4 tooth 9 across No. 1, No. 2, and No. 3 teeth 9. The led-out conducting wire 12 is hooked to No. 7 segment 15. Thereby, No. 1 segment 15 and No. 7 segment 15 are short-circuited. The portion of the conducting wire 12 between the segments constitutes a going portion 54a of the equalizer 54.

The conducting wire 12 which is hooked to No. 7 segment 15 is led out to tooth 9 side through the slot 11 between No. 4 tooth 9 and No. 5 tooth 9. Subsequently, the conducting wire 12 is led out to the commutator 4 side through the slot 11 between No. 2 tooth 9 and No. 1 tooth 9 across No. 4, No. 3, and No. 2 teeth 9. The led-out conducting wire 12 is hooked to No. 1 segment 15 again. Thereby, No. 1 segment 15 and No. 7 segment 15 are short-circuited. The portion of the conducting wire 12 between the segments also constitutes a return portion 54b of the equalizer 54.

Next, the conducting wire 12 which is hooked to No. 1 segment 15 is lead out to the tooth 9 side. This portion corresponds to the leader line 52. Thereafter, the conducting wire 12 is wound around No. 1 tooth 9 through the slot 11 between No. 12 tooth 9 and No. 1 tooth 9, and therefore, the coil 10 is formed. The coil 10 is formed in a clockwise direction (CW) when viewing from the tip side of the tooth 9.

Moreover, after the conducting wire 12 is wound around No. 1 tooth 9 a predetermined number of times, the conducting wire 12 which is led out to the commutator 4 side through the slot 11 between No. 1 tooth 9 and No. 2 tooth 9 is transferred to No. 4 tooth 9 across No. 2 and No. 3 teeth 9. Accordingly, the portion of the conducting wire 12 between the teeth 9 constitutes the connecting wire 53.

Subsequently, the conducting wire 12 is wound around No. 4 tooth 9 through the slot 11 between No. 3 tooth 9 and No. 4 tooth 9, and therefore, the coil 10 is formed. The coil 10 is also formed in a clockwise direction (CW) when viewing from the tip side of the tooth 9. Moreover, after the conducting wire 12 is wound around No. 4 tooth 9 a predetermined number of times, the conducting wire 12 which is led out to the commutator 4 side through the slot 11 between No. 4 tooth 9 and No. 5 tooth 9 is hooked to No. 8 segment 15.

The conducting wire 12 which is hooked to No. 8 segment 15 is led out to the tooth 9 side through the slot 11 between No. 3 tooth 9 and No. 4 tooth 9. Subsequently, the conducting wire 12 is led out to the commutator 4 side through the slot 11 between No. 6 tooth 9 and No. 7 tooth 9 across No. 4, No. 5, and No. 6 teeth 9. The led-out conducting wire 12 is hooked to No. 14 segment 15. Thereby, No. 8 segment 15 and No. 14 segment 15 are short-circuited. The portion of the conducting wire 12 between the segments constitutes a going portion 54a of the equalizer 54.

The conducting wire 12 hooked to No. 14 segment 15 is led out the tooth 9 side through the slot 11 between No. 7 tooth 9 and No. 8 tooth 9. Subsequently, the conducting wire 12 is led out to the commutator 4 side through the slot 11 between No. 5 tooth 9 and No. 4 tooth 9 across No. 7, No. 6, and No. 5 teeth 9. The led-out conducting wire 12 is hooked to No. 8 segment 15 again. Thereby, No. 8 segment 15 and No. 14 segment 15 are short-circuited. The portion of the conducting wire 12 between the segments also constitutes a return portion 54b of the equalizer 54.

Next, the conducting wire 12 which is hooked to No. 8 segment 15 is wound around No. 3 tooth 9 through the slot 11 between No. 3 tooth 9 and No. 4 tooth 9, and therefore, the coil 10 is formed. The coil 10 is formed in a counterclockwise direction (CCW) when viewing from the tip side of the tooth 9.

Moreover, after the conducting wire 12 is wound around No. 3 tooth 9 a predetermined number of times, the conducting wire 12 is led out to the commutator 4 side through the slot 11 between No. 2 tooth 9 and No. 3 tooth 9. Thereafter, the conducting wire 12 is transferred to No. 12 tooth 9 across No. 2 and No. 1 teeth 9. The portion of the conducting wire 12 between the teeth 9 constitutes the connecting wire 53.

Subsequently, the conducting wire 12 is wound around No. 12 tooth 9 through the slot 11 between No. 1 tooth 9 and No. 12 tooth 9, and therefore, the coil 10 is formed. The coil 10 is also formed in a counterclockwise direction (CCW) when viewing from the tip side of the tooth 9. Moreover, after the conducting wire 12 is wound around No. 12 tooth 9 a predetermined number of times, the conducting wire 12 which is led out to the commutator 4 side through the slot 11 between No. 11 tooth 9 and No. 12 tooth 9 is hooked to No. 21 segment 15.

According to the above processing, the winding structure 50 of part (1) in Fig. 6 is formed.

Thereafter, the winding structure 50 of the (2) to (5) in Fig. 6 is formed by being processed through the same method. That is, No. 1 segment 15 which is the winding start terminal replaces No. 21, No. 17, No. 13, or No. 9 segment 15, and the relative positional relationship of the other each segment 15 or each tooth 9 is also replaced. Simply by doing this, the conducting wire 12 is wound according to the same order as that of the above-described part (1) of Fig. 6.

In part (6) in Fig. 6, only the processing of the winding end terminal is different from the other portions such as part (1), the other processing content is the same as that of part (1) or the like. Specifically, the conducting wire 12 is wound around No. 2 tooth a predetermined number of times and the counterclockwise coil 10 is formed. Thereafter, the conducting wire 12 is led out to the tooth 9 side through the slot 11 between No. 2 tooth 9 and No. 3 tooth 9. The led-out conducting wire 12 is led out to the commutator 4 side again through the slot 11 between No. 4 tooth 9 and No. 5 tooth 9 across No. 3 and No. 4 teeth 9.

Finally, the led-out conducting wire 12 is hooked to No. 7 segment 15 and becomes the winding end terminal.

Two kinds of coils 10 are wound around each tooth 9 of the winding structure 50 formed in the way. That is, the clockwise (CW) element coil 10a and the counterclockwise (CCW) element coil 10b, which are two kinds of coils 10 wound in opposite directions, are formed on each of the teeth 9 when viewed from the tip side of the tooth 9. Due to the fact that the coils 10 are constituted in this way, motor performance can be improved. Specifically, the generation of sparks can be prevented, and the life span of the motor can be improved.

To explain this point in detail, generally, in the motor with the brush, current is supplied to the armature through the brush which makes sliding contact with the rotating commutator, and the motor is rotated. At this time, there is a concern that spark discharge, that is, sparks, may be generated between the brush and the commutator. Specifically, when the segment which makes sliding contact with the brush is replaced, since the direction in which current flows is reversed in a very short time, a so-called surge voltage is generated in proportion to the rapid change of the current due to inductance of the coil. Spark is generated by effects such as the surge voltage. If the spark is generated, life span of the brush is shortened, and life span of the motor is decreased.

In contrast, in the motor with the brush of the present embodiment, each coil 10 is constituted by two kinds of

element coils

10a and 10b. Moreover, current is supplied to each

element coil

10a, 10b at regular intervals through the positive pole brush 5a and the negative pole brush 5b, the current supplied to each

element coil

10a, 10b is set so at to flow in the same winding direction.

In addition, the positive pole brush 5a and the negative pole brush 5b are disposed so that a supply timing of the current to the element coils 10a and 10b is deviated. If the supply timing of the current to the element coils 10a and 10b of each coil 10 is deviated, the rate of change of the current at the time of replacing the segment is decreased. As a result, the generation of sparks is effectively suppressed, and the life span of the motor can be improved.

In addition, even though the winding direction of each of a plurality of kinds of coils 10 which is formed in single tooth 9 is the same direction, the similar effects can be obtained by adjusting the flow of current to be supplied. That is, it is sufficient if the winding structure 50 has a structure in which a plurality of kinds of coils 10 is formed on a single tooth 9 and the conducting wire 12 forming each coil 10 is hooked to the segments 15 which are different to each other.

Moreover, in order to improve motor performance, wiring of the equalizer 54 is considered.

In the first place, the equalizer 54 which connects between two identical segments 15 is configured as a plurality. Specifically, the equalizer 54 includes the going portion 54a and the return portion 54b which go and return between two identical segments 15. Thereby, since current capacity of the equalizer 54 can be secured even though the conducting wire 12 such as the coil 10 is used, the number of the brushes can be decreased. In addition, the total number of the going portions 54a and the return portions 54b need not necessarily be two, and may be 3 or more.

Secondly, the going portion 54a and the return portion 54b are disposed under a predetermined condition. That is, among values which are integer multiples of the value which is acquired by dividing the number of the slots 11 by the number of pole pairs 3b, the number which becomes the integer is given as the expansion value. Moreover, in this case, a group of teeth 9, which is arranged so as to be continued in the circumferential direction and has the same number as the expansion value, is given as the element teeth group. At this time, the going portion 54a and the return portion 54b are disposed so that the going portion 54a and the return portion 54b are wound across the element teeth group through the slot positioned at both sides of the element teeth group. The winding structure 50 is referred to as a "first winding structure 50".

For example, in a case of motor having 8 poles and 10 slots, the number of the slots 11 is 10 and the number of the pole pairs 3b is 4. Accordingly, the value acquired by dividing 10 which is the number of the slots 11 by 4 which is the number of the pole pairs 3b is 2.5. Moreover, among the values which are integer multiples of 2.5, the numbers which become integers are 5, 10, and the like. Therefore, the expansion value becomes a multiple of 5.

In the present embodiment, the number of the slots 11 is 12 and the number of the pole pairs 3b is 4. Accordingly, the value acquired by dividing 12 which is the number of the slots 11 by 4 which is the number of the pole pairs 3b is 3. Moreover, among the values which are integer multiple of 3, the numbers which become integers are 3, 6, or the like. Therefore, the expansion value becomes a multiple of 3.

In this way, there is a case where the number of the slots 11 is not an integer multiple of the number of the pole pairs 3b and a case where the number of the slots 11 is an integer multiple of the number of the pole pairs 3b. However, as in the present embodiment, it is preferable that the number of the slots 11 is an integer multiple of the number of the pole pairs 3b. As a result of dividing the number of the slots 11 by the number of pole pairs 3b without a remainder, the minimum value of the expansion value is decreased. Therefore, an effective winding structure 50 can be formed.

Moreover, the going portion 54a and the return portion 54b are wound across the group of teeth 9 through slots 11 which are positioned at both sides in the circumferential direction of a group of teeth 9, that is, a so-called element teeth group which is arranged so as to be continued with the same number as the expansion value. In addition, according to the present embodiment, the same number as the expansion value is 3n.

For example, according to the present embodiment, as shown in Fig. 8, one pole pair 3b always has a relationship which faces the portion of three teeth 9, even when the motor is rotated, the relationship is not changed only by deviation of the positional relationship between one pole pair 3 and the portion of three teeth 9. Accordingly, the circuit (coil) of the going portion 54a or the return portion 54b which are wound across the element teeth group always faces the portion of an integer multiple of the pole pair 3b. As a result, since induced voltage is not generated in each circuit of the going portion 54a and the return portion 54b, short-circuit current does not flow in each circuit of the going portion 54a and the return portion 54b. Accordingly, in the loop circuit which is formed by the going portion 54a and the return portion 54b, the circulating short-circuit current does not flow. As a result, the motor performance is improved. Moreover, since induced voltage is not generated in each circuit of the going portion 54a and the return portion 54b, there is no effect on the voltage which is supplied through the brushes. As a result, a loss of motor performance is not generated.

The going portion 54a and the return portion 54b may be wound across the same element teeth group. However, as in the present embodiment, it is preferable that the going portion 54a and the return portion 54b are wound across different element teeth groups. In doing so, since the draw-in direction and the draw-out direction of the conducting wire 12 with respect to the hook portion 15a are different to each other, the conducting wire 12 can be easily hooked to the hook portion 15a. As a result, productivity is improved.

According to the present embodiment, as shown by the reference numeral 20 in Fig. 7A, the element teeth group is formed by three teeth 9 of No. 1 to No. 3, three teeth 9 of No. 2 to No. 4, three teeth 9 of No. 4 to No. 6, three teeth group 9 of No. 5 to No. 7, and the like. The number of the teeth 9 constituting the element teeth group may be different in the going portion 54a and the return portion 54b.

However, in some cases, the equalizer 54 can be wired under the above-described condition due to the specifications of the motor or the like.

For example, if the motor has 8 poles and 10 slots, it is preferable that the equalizer 54 is wound across one group of 5 or 10 teeth 9. However, for example, in some cases, the equalizer 54 needs be wound across one group of 4 or less teeth 9. In this case, the following is preferable. That is, the total number of the going portions 54a and the return portions 54b is even, and each of the going portions 54a and the return portions 54b is wired so as to be wound across one group of the same teeth 9 through the same slot 11. This winding structure 50 is referred to as a second winding structure 50.

This will be explained with reference to Fig. 9, and the motor having 8 poles and 10 slots will be used as the example. In this case, one pole pair 3b always faces 2.5 pieces of the teeth 9. Accordingly, in the case where the going portion 54a and the return portion 54b are wound across one group of two teeth 9, one pole pair 3b partially faces the circuit which is formed by the going portion 54a and the return portion 54b. In addition, in the case where the going portion 54a and the return portion 54b are wound across one group of 3 or 4 teeth 9, the circuit which is formed by the going portion 54a and the return portion 54b partially faces one pole pair 3b. As a result, induced voltage is generated in each circuit of the going portion 54a and the return portion 54b by rotation of the motor.

Accordingly, if phase deviation is generated in the induced voltages which are respectively generated between the circuit formed by the going portion 54a and the circuit formed by the return portion 54b, circulating short-circuit current is generated in the loop circuit formed by the going portion 54a and the return portion 54b. As a result, a brake force is generated.

Therefore, the going portion 54a and the return portion 54b are made so as to be a pair of circuits which reciprocate to be wound across one group of the same teeth 9. If the going portion 54a and the return portion 54b are the path which is wound across one group of the same teeth 9, the number of the teeth 9 in which the going portion 54a and the return portion 54b straddle is not considered. That is, if the going portion 54a and the return portion 54b are the path which is wound across one group of the same teeth 9, the number of the teeth 9 covered by the going portion 54a and the return portion 54b may be 1 or more. Thereby, the induced voltages generated in both circuits always become the same phase, the circulating short-circuit current does not flow in the loop circuit which is formed by the going portion 54a and the return portion 54b. As a result, the motor performance is improved. Moreover, at this time, the equalizer 54 reciprocates a plurality of times and is wound across one group of the same teeth 9, and a plurality of going portions 54a and return portions 54b may be formed respectively.

With respect to the effects of the above-described first winding structure 50 (embodiment 1) and second winding structure 50 (embodiment 2), the following confirmation tests were performed.

The embodiment 1 is the motor which has 8 poles and 12 slots of the first winding structure in the above-described embodiment. The basic configuration of the equalizer 54 is shown in Fig. 10. Embodiment 2 is the motor which has 8 poles and 10 slots of the second winding structure in the above-described embodiment. In the embodiment 2, the going portion 54a and the return portion 54b are each wound around for each one across one group of the teeth which are constituted of two teeth. The basic configuration of the equalizer 54 is shown in Fig. 11. As comparative example, in the motor of the embodiment 2, a test was performed with respect to a case where the circuit of the going portion 54a and the return portion 54b is formed through different paths. The basic configuration of the equalizer 54 is shown in Fig. 12.

The results of the confirmation tests which were collected with respect to the relationship between the motor efficiency and torque in the embodiment 1 or the like are shown in Fig. 13. In Fig. 13, an alternate long and short dash line represents the embodiment 1, a broken line represents the embodiment 2, and a solid line represents the comparative example.

It was observed that the motor efficiency of the

embodiments

1 and 2 is improved compared to that of the comparative example. Among them, the motor efficiency of the embodiment 1 is higher as a whole than that of the embodiment 2, and it was observed that the embodiment is particularly effective.

Only selected preferred embodiments have been chosen to illustrate the present invention. To those skilled in the art, however, it will be apparent from the foregoing disclosure that various changes and modifications can be made herein without departing from the scope of the present invention as defined in the appended claims. Furthermore, the foregoing description of the preferred embodiments according to the present invention is provided for illustration only, and not for limiting the invention as defined by the appended claims and their equivalents.

For example, the winding method in the coil of the motor is not limited to the concentrated winding, and a distributed winding may be applied. That is, the coil 10 may be formed by winding the coil winding wire 51 around a plurality of teeth 9. In addition, the winding structure 50 is formed by using single conducting wire 12. However, the winding structure 50 may be formed by using a plurality of conducting wires 12.

For example, the motor of the present invention is suitable for a motor which is mounted on vehicle.

1: shaft
2: armature
2a: armature core
3: magnet
3a: magnetic pole (N pole, S pole)
3b: pole pair
4: commutator
5: brush
6: housing
9: tooth
10: coil
11: slot
15: segment
20: element teeth group
50: winding structure
51: coil winding wire
52: leader line
53: connecting wire
54: equalizer
54a: going portion
54b: return portion
J: rotating shaft

Claims

A motor comprising:
an armature;
a commutator that includes a plurality of segments;
a shaft that is rotated around a central axis along with the armature and the commutator;
a magnet that is disposed around the armature and in which an N pole and an S pole are alternatively arranged in a circumferential direction;
a brush that is disposed around the commutator and makes sliding contact with the segment; and
a winding structure that is disposed over the armature and the commutator,
wherein the armature includes a plurality of coils, and an armature core that is fixed to the shaft,
the armature core includes a plurality of teeth that are radially extended in a radial direction, and a plurality of slots that are disposed between the teeth and extended in an axial direction,
the winding structure includes a coil winding wire that constitutes the coil, a leader line that connects between the coil and the segment, a connecting wire that connects between two coils, and an equalizer that connects between two segments,
the equalizer includes a going portion and a return portion which are wound across one group of the teeth through the slot, and connect between two identical segments, and
in a case where the number which becomes the integer is given as the expansion value among values which are integer multiple of the value which is acquired by dividing the number of the slots by the number of pole pairs constituted of the N pole and the S pole, when one group of the teeth, which is arranged so as to be continued in the circumferential direction and has the same number as the expansion value, is given as an element teeth group, the going portion and the return portion are wound across the element teeth group through the slot positioned at both sides of the element teeth group.
A motor comprising:
an armature;
a commutator that includes a plurality of segments;
a shaft that is rotated around a central axis along with the armature and the commutator;
a magnet that is disposed around the armature and in which an N pole and an S pole are alternatively arranged in a circumferential direction;
a brush that is disposed around the commutator and makes sliding contact with the segment; and
a winding structure that is disposed over the armature and the commutator,
wherein the armature includes a plurality of coils, and an armature core that is fixed to the shaft,
the armature core includes a plurality of teeth that are radially extended in a radial direction, and a plurality of slots that are disposed between the teeth and extended in an axial direction,
the winding structure includes a coil winding wire that constitutes the coil, a leader line that connects between the coil and the segment, a connecting wire that connects between two coils, and an equalizer that connects between two segments,
the equalizer includes a going portion and a return portion which are wound across the teeth through the slot and connect between two identical segments,
the number of the going portion and the return portion is even, and
each of the going portion and the return portion is wound across the same teeth through the same slot.
The motor according to claim 1,
wherein the number of the slots is an integer multiple of the number of the pole pairs.
The motor according to claim 1 or 3,
wherein the element teeth group covered by the going portion is different from the element teeth group covered by the return portion.
The motor according to any one of claims 1 to 4,
wherein the coil is a distribution winding in which the coil winding wire is wound over a plurality of the teeth.
The motor according to any one of claims 1 to 4,
wherein the coil is a concentration winding in which the coil winding wire is wound for each tooth.
The motor according to claim 6,
wherein two kinds of element coils are wound around each of the teeth, and
the number of the segments is double of the number of slots.
The motor according to any one of claims 1 to 7,
wherein the coil winding wire, the leader line, the connecting wire, and the equalizer are a single continuous conducting wire.