CN110024271B

CN110024271B - Electric motor

Info

Publication number: CN110024271B
Application number: CN201780066674.3A
Authority: CN
Inventors: 中村雄一朗; 水田贵裕; 阿里夫·扎伊尼; 元吉研太; 伊藤一将; 田中敏则; 山口信一
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2016-11-01
Filing date: 2017-09-19
Publication date: 2020-11-24
Anticipated expiration: 2037-09-19
Also published as: JPWO2018083898A1; KR20190053942A; CN110024271A; TWI661664B; JP6516924B2; TW201820767A; KR102128715B1; WO2018083898A1

Abstract

In the motor, the armature core has a plurality of teeth arranged adjacent to each other. A plurality of permanent magnets are housed in each of the plurality of teeth. The salient pole member has 1 or more salient poles, and the salient poles are arranged in a state of facing the teeth. Each of the permanent magnets housed in 2 teeth adjacent to each other is disposed so that the same magnetic poles face each other. If the pitch of the teeth is set to P1 and the pitch of the salient poles is set to P2, (P1/P2) < 1/6, or 5/6 < (P1/P2) < 7/6 is satisfied.

Description

Electric motor

Technical Field

The present invention relates to a motor having an armature provided with a permanent magnet.

Background

Conventionally, there is known an electric motor configured such that a salient pole member having salient poles is rotated with respect to an armature in which permanent magnets are individually housed in respective teeth of an armature core. In the conventional motor as described above, the armature windings are individually provided in the respective teeth by concentrated winding (see, for example, patent document 1).

Patent document 1: japanese laid-open patent publication No. 2002-199679

Disclosure of Invention

In the conventional motor shown in patent document 1, since the number of salient poles of the salient pole member is 5 and the number of teeth of the armature is 6, magnetomotive force of 3 pole pairs generated by 6 permanent magnets is modulated by 5 salient poles to generate magnetic flux of 2 pole pairs. Therefore, if the relationship between the number of magnetic poles formed by the armature winding and the number of teeth is expressed as "the number of magnetic poles: in the conventional motor shown in patent document 1, in the combination of pole grooves of the "tooth number" series, the ratio of 2: the cogging torque increases when the 3-series pole groove combinations are operated.

The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a motor capable of reducing cogging torque or cogging thrust.

The motor according to the present invention includes: an armature having an armature core, a plurality of permanent magnets, and a plurality of armature windings, the armature core having a plurality of teeth arranged adjacent to each other, the plurality of permanent magnets being accommodated in the plurality of teeth, respectively, the plurality of armature windings being provided in the plurality of teeth, respectively; and a salient pole member having 1 or more salient poles, the salient poles being arranged in a state facing the teeth, the armature and the salient pole member being relatively movable in a direction in which the plurality of teeth are arranged, the same magnetic poles being arranged facing each other in each of the permanent magnets housed in 2 teeth adjacent to each other, and satisfying (P1/P2) < 1/6 or 5/6 < (P1/P2) < 7/6, with a pitch of the teeth being P1 and a pitch of the salient poles being P2.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the motor of the present invention, the relationship between the tooth pitch P1 and the salient pole pitch P2 satisfies the above equation, and therefore the fundamental wave frequency of the slot can be increased. This can reduce the amplitude value of the fundamental wave frequency of the cogging, and can reduce the cogging torque or the cogging thrust.

Drawings

Fig. 1 is a structural diagram showing a motor according to embodiment 1 of the present invention.

Fig. 2 is a wiring diagram showing the 12 armature windings of fig. 1.

Fig. 3 is a structural diagram showing a motor according to embodiment 2 of the present invention.

Fig. 4 is a structural diagram showing a motor according to embodiment 3 of the present invention.

Fig. 5 is a structural diagram showing a motor according to embodiment 4 of the present invention.

Fig. 6 is a structural diagram showing a motor according to embodiment 5 of the present invention.

Fig. 7 is a structural diagram showing a motor according to embodiment 6 of the present invention.

Fig. 8 is a structural diagram showing a motor according to embodiment 7 of the present invention.

Fig. 9 is a structural diagram showing a motor according to embodiment 8 of the present invention.

Fig. 10 is a structural diagram showing a motor according to embodiment 9 of the present invention.

Fig. 11 is a structural diagram showing a motor according to embodiment 10 of the present invention.

Fig. 12 is a table showing combinations of values of k, m, and Q when Q is 3 · k · m in the motor according to embodiment 10 of the present invention.

Fig. 13 is a table showing combinations of values of k, m, and N when N is (3 · k +0.5) · m in the motor according to embodiment 10 of the present invention.

Fig. 14 is a table showing combinations of values of k, m, and N when N is (3 · k-0.5) · m in the motor according to embodiment 10 of the present invention.

Fig. 15 is a table showing combinations of values of k, m and a pole groove combination when N is (3 · k +0.5) · m in the motor according to embodiment 10 of the present invention.

Fig. 16 is a table showing combinations of values of k, m and a pole groove combination when N is (3 · k-0.5) · m in the motor according to embodiment 10 of the present invention.

Fig. 17 is a structural diagram showing a motor according to embodiment 11 of the present invention.

Fig. 18 is a structural diagram showing a motor according to embodiment 12 of the present invention.

Fig. 19 is a vector diagram showing the 1f component of the cogging torque produced by each tooth of fig. 18.

Fig. 20 is a structural diagram showing a motor according to embodiment 13 of the present invention.

Fig. 21 is a structural diagram showing a motor according to embodiment 14 of the present invention.

Fig. 22 is a structural diagram showing a motor according to embodiment 15 of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1.

Fig. 1 is a structural diagram showing a motor according to embodiment 1 of the present invention. In the figure, a motor 1 includes: an annular armature 2 as a stator; and a salient pole member 3 as a rotor disposed inside the armature 2 and rotating relative to the armature 2. Therefore, in the present example, the motor 1 is a rotary motor.

The armature 2 has: an armature core 4 made of iron; a plurality of permanent magnets 5 housed in the armature core 4; and a plurality of armature windings 6 provided to the armature core 4.

The armature core 4 includes: an annular core holder 7; and a plurality of teeth 8 respectively projecting from an inner surface of the core print 7 toward the salient pole members 3.

The plurality of teeth 8 are arranged adjacent to each other at equal intervals in the circumferential direction of the armature core 4. Thus, grooves 9 are formed as spaces between the plurality of teeth 8. The number of grooves 9 is the same as the number of teeth 8. Each slot 9 is open toward the salient pole members 3. In this example, the number of teeth 8 is 12, and the number of grooves 9 is also 12.

The permanent magnets 5 are individually housed in the teeth 8. In this example, the plate-like permanent magnet 5 arranged in the radial direction of the armature 2 is accommodated in the circumferential center portion of the teeth 8. In addition, the permanent magnets 5 accommodated in the 2 teeth 8 adjacent to each other are arranged such that the same magnetic poles face each other. Therefore, all the permanent magnets 5 adjacent to each other have magnetic poles alternately arranged in the circumferential direction of the armature 2. In this example, the permanent magnets 5 are exposed from the teeth 8 on the inner peripheral surface of the armature core 4, and are covered with the core seats 7 on the outer peripheral surface of the armature core 4.

The armature windings 6 are individually provided in the teeth 8 by concentrated winding. Thus, in the present example, the number of armature windings 6 is 12. Each armature winding 6 is accommodated in the slot 9. When three phases are represented by U-phase, V-phase, and W-phase, respectively, 4 armature windings 6 of the armature windings 6 are U-phase armature windings U11, U12, U21, and U22, the other 4 armature windings 6 are V-phase armature windings V11, V12, V21, and V22, and the remaining 4 armature windings 6 are W-phase armature windings W11, W12, W21, and W22. As shown in fig. 1, the 12 armature windings 6 are arranged in the order of + U11, -U12, -V11, + V12, + W11, -W12, -U21, + U22, + V21, -V22, -W21, + W22 in the counterclockwise direction in fig. 1, corresponding to each of the 12 teeth 8. However, "+" and "-" indicate different winding polarities of the armature windings 6, and indicate that directions of electromagnetic fields generated in the armature windings 6 are opposite to each other in the radial direction when currents in the same direction flow through the armature windings 6.

Fig. 2 is a wiring diagram showing the 12 armature windings 6 of fig. 1. In the armature 2, in consideration of the symmetry of the induced voltage of each armature winding 6, a U-phase series circuit in which U-phase armature windings U11, U12, U21, and U22 are connected in series in this order, a V-phase series circuit in which V-phase armature windings V11, V12, V21, and V22 are connected in series in this order, and a W-phase series circuit in which W-phase armature windings W11, W12, W21, and W22 are connected in series in this order are connected at a common neutral point. That is, in the armature 2, the plurality of armature windings 6 are wired by Y-wiring.

The salient pole member 3 is disposed coaxially with the armature 2. Thus, the salient-pole members 3 have an axis a common to the armature 2. In addition, a gap, i.e., an air gap, exists between the salient pole members 3 and the armature 2. Thereby, the armature 2 and the salient pole member 3 can be relatively moved in the direction in which the plurality of teeth 8 are arranged, that is, in the circumferential direction of the armature 2.

The salient pole member 3 has: a cylindrical salient pole member body 31; and 1 or more salient poles 32 provided at an outer peripheral portion of the salient pole member body 31. In this example, the number of salient poles 32 is 11. The salient poles 32 are arranged at equal intervals in the direction in which the plurality of teeth 8 are arranged, that is, in the circumferential direction of the armature 2.

Here, an angle formed by 2 straight lines connecting one circumferential end of each of the 2 teeth 8 adjacent to each other and the axis a is θ 1, and an angle formed by 2 straight lines connecting one circumferential end of each of the 2 salient poles 32 adjacent to each other and the axis a is θ 2. Further, an angle formed by 2 straight lines connecting both ends of the permanent magnet 5 in the circumferential direction and the axis a is θ 3. A surface passing through the end surfaces of the plurality of teeth 8 and set along the circumferential direction in which the plurality of teeth 8 are arranged is set as a pitch reference surface. In this example, the pitch reference plane is a cylindrical plane centered on the axis a.

In the common pitch reference plane, the circumferential distance corresponding to the range of θ 1 is set as the pitch P1 of the teeth 8, the circumferential distance corresponding to the range of θ 2 is set as the pitch P2 of the salient poles 32, and the circumferential distance corresponding to the range of θ 3 is set as the pitch P3 of the permanent magnets 5. That is, the circumferential interval between the teeth 8 in the common pitch reference plane is set to the pitch P1 of the teeth 8, the circumferential interval between the salient poles 32 in the common pitch reference plane is set to the pitch P2 of the salient poles 32, and the thickness of the permanent magnets 5 in the common pitch reference plane is set to the pitch P3 of the permanent magnets 5.

If the pitch P1 of the teeth 8 and the pitch P2 of the salient poles 32 are defined as described above, the relationship between P1 and P2 satisfies the following expression (1) or (2).

(P1/P2)＜1/6…(1)

5/6＜(P1/P2)＜7/6…(2)

Further, if the number of teeth 8 is Q and the number of salient poles 32 facing Q teeth 8 is N, the relationship of the following expression (3) is established. Further, the number N of salient poles 32 need not be a natural number.

(P1/P2)＝(N/Q)…(3)

In this example, Q is 12 and N is 11, and equation (2) is satisfied.

In the motor 1, the 6-pole pair magnetomotive force generated by the 12 permanent magnets 5 is modulated by the 11 salient poles 32 to generate 5-pole pair magnetic fluxes. Therefore, in this example, the motor 1 operates with 10 poles and 12 slots. That is, if the relationship between the number of magnetic poles formed by the plurality of armature windings 6 and the number of teeth 8 is expressed as "the number of magnetic poles: tooth number "series of pole-slot combinations, the motor 1 is driven in this example with a speed ratio of 5: the 6-series polar trough combinations operate.

The relationship between the pitch P3 of the permanent magnets 5 and the pitch P1 of the teeth 8 satisfies the following expression (4).

5＜P1/P3＜10…(4)

In this example, P1/P3 is 7.5, and formula (4) is satisfied.

When P1/P3. ltoreq.5, the ratio of the thickness of the permanent magnet 5 to the width of the teeth 8 becomes too large, and magnetic saturation tends to occur in the teeth 8. In addition, when 10. ltoreq. P1/P3, the ratio of the thickness of the permanent magnet 5 to the width of the teeth 8 becomes too small, and the magnetic flux of the permanent magnet 5 cannot be sufficiently obtained. Accordingly, the relationship between the pitch P3 of the permanent magnets 5 and the pitch P1 of the teeth 8 satisfies expression (4), and the torque of the motor 1 can be increased.

In the motor 1 described above, the relationship between the pitch P1 of the teeth 8 and the pitch P2 of the salient poles 32 satisfies the expression (2), and therefore, the relationship can be compared with the conventional 2: the 3 series of pole slot combinations increase the fundamental frequency of the tooth slot compared to the others. Specifically, since the number Q of teeth 8 is 12 and the number N of salient poles 32 facing the teeth 8Q is 11, the motor 1 can be operated in a 10-pole 12-slot, and the motor can be operated in a similar manner to the conventional 2: the 3 series of pole slot combinations increase the fundamental frequency of the tooth slot compared to the others. Thus, the amplitude value of the fundamental wave frequency of the cogging can be reduced, and the cogging torque can be reduced. In addition, in conventional 2: in the case of 3 series, the winding factor is 0.866, while in embodiment 5: in the 6-series pole-slot combination, the winding factor was 0.933. Therefore, in the present embodiment, the winding factor is similar to the conventional 2: the torque of the motor 1 can be improved as compared with the case of the 3-series.

Further, since the relationship between the pitch P3 of the permanent magnet 5 and the pitch P1 of the teeth 8 satisfies the formula (4), the magnetic flux of the permanent magnet 5 can be sufficiently obtained, and magnetic saturation is less likely to occur in the teeth 8. This can increase the induced voltage of the armature 2, and increase the torque of the motor 1.

In the above example, the winding arrangement of the plurality of armature windings 6 is a normal winding arrangement of the motor 1 operating with 10-pole 12 slots, but the number of windings is set in the following range from 5: in the case of another pole slot combination different from the 6-series pole slot combination, for example, 8-pole 9 slots, 14-pole 15 slots, etc., a normal winding arrangement corresponding to the other pole slot combination can be applied as a winding arrangement of the plurality of armature windings.

Embodiment 2.

Fig. 3 is a structural diagram showing a motor according to embodiment 2 of the present invention. In the present embodiment, Q is 12 and N is 13. Thus, in the present embodiment, the relationship between P1 and P2 satisfies the above expression (2). Further, 12

armature windings

6 and 12 teeth 8 are arranged in the order of + U11, -U12, -W11, + W12, + V11, -V12, -U21, + U22, + W21, -W22, -V21, + V22 in the counterclockwise direction in fig. 3, respectively. However, "+" and "-" indicate different winding polarities of the armature winding 6 as in embodiment 1.

In the present embodiment, the magnetomotive force of 6 pole pairs generated by the 12 permanent magnets 5 is modulated by the 13 salient poles 32 to generate magnetic fluxes of 7 pole pairs. Therefore, in this example, the motor 1 operates with 14 poles and 12 slots. That is, in this example, the motor 1 is driven at a speed of 7: the 6-series polar trough combinations operate. The other structure is the same as embodiment 1.

As described above, even if Q is 12 and N is 13, the relationship between P1 and P2 can satisfy expression (2). Specifically, since Q is 12 and N is 13, the motor 1 can be operated in a 14-pole 12-slot, and the ratio of Q to N can be set to 5: 6 series Large 7: the motor 1 is operated by the 6-series pole groove combination. This can further reduce the cogging torque. In addition, the number of permanent magnets 5 per 1 pole can be reduced, and thus the magnetic flux per 1 pole passing through the core print 7 can be reduced. This makes it difficult for magnetic saturation in the core print 7 to occur, and the radial thickness of the core print 7 can be reduced. Therefore, the winding area of the armature winding 6 can be enlarged, and the copper loss of the armature winding 6 can be reduced.

Embodiment 3.

Fig. 4 is a structural diagram showing a motor according to embodiment 3 of the present invention. In the present embodiment, Q is 12 and N is 1. Thus, in the present embodiment, the relationship between P1 and P2 satisfies the above expression (1).

The salient pole members 3 are cylindrical in shape. The salient pole members 3 are disposed inside the armature 2 in a state where the cylindrical center axes of the salient pole members 3 are eccentric from the axis a. The salient pole members 3 rotate relative to the armature 2 about the axis a. Thereby, the salient pole member 3 having 1 salient pole 32 is constituted.

When the number of salient poles 32 is 1, the angle from one rotation of salient pole 32 around salient pole member 3 to the original salient pole 32 is θ 2, and θ 2 is 360 degrees which is an angle corresponding to one rotation of salient pole member 3. Therefore, the pitch P2 of the salient poles 32 becomes the circumferential distance of the pitch reference plane corresponding to one turn.

In the present embodiment, the magnetomotive force of 6 pole pairs generated by the 12 permanent magnets 5 is modulated by the 1 salient pole 32 to generate magnetic flux of 7 pole pairs. Therefore, in this example, the motor 1 operates with 14 poles and 12 slots. That is, in this example, the motor 1 is driven at a speed of 7: the 6-series polar trough combinations operate. The other structure is the same as embodiment 2.

As described above, even if Q is 12 and N is 1, the relationship between P1 and P2 can satisfy expression (1). Specifically, since Q is 12 and N is 1, as in embodiment 2, the ratio of 7: the motor 1 is operated by the 6-series pole groove combination, and the cogging torque can be further reduced. Further, since the number of permanent magnets 5 per 1 pole can be reduced, the radial thickness of the core print 7 can be reduced, and the copper loss of the armature winding 6 can also be reduced. Further, the relationship between P1 and P2 satisfies expression (1), and thus the number of salient poles 32 in the salient pole member 3 can be reduced, and the salient pole member 3 can be easily manufactured.

Embodiment 4.

Fig. 5 is a structural diagram showing a motor according to embodiment 4 of the present invention. In the present embodiment, the armature 2 and the salient pole member 3 are each arranged in a linear direction. That is, in this example, the motor 1 is a linear motor. In this example, the shapes of the armature core 4 and the salient-pole members 3 are such that the armature core 4 and the salient-pole members 3 of embodiment 1 are developed in the circumferential direction in a linear direction.

In the motor 1, the iron salient pole members 3 are arranged in a linear direction as a conveyance path of the linear motor. The armature 2 is movable in a linear direction along the salient pole members 3. The salient pole member body 31 is a plate-like member arranged along the linear direction in which the armature 2 moves. The salient poles 32 are arranged at equal intervals in a linear direction of the salient pole member body 31.

The armature 2 is arranged in parallel with the salient pole member 3. Thereby, the plurality of teeth 8 are arranged at equal intervals in the linear direction in which the plurality of salient poles 32 are arranged. In this example, the number of teeth 8 of the armature core 4 is 12. The armature 2 is disposed with each tooth 8 facing the salient pole member 3.

In this example, the permanent magnets 5 are individually housed in the teeth 8, and the permanent magnets 5 are exposed on the surface of the armature core 4 on the salient pole member 3 side and the surface of the armature core 4 on the opposite side to the salient pole member 3 side.

Here, a plane passing through the end surface of the plurality of teeth 8 and set along the linear direction in which the plurality of teeth 8 are arranged is set as a pitch reference plane. The linear direction interval between the teeth 8 in the common pitch reference plane is defined as a pitch P1 of the teeth 8, and the linear direction interval between the salient poles 32 in the common pitch reference plane is defined as a pitch P2 of the salient poles 32. If the pitch P1 of the teeth 8 and the pitch P2 of the salient poles 32 are defined as described above, the relationship between P1 and P2 satisfies the above expression (1) or (2).

In the present embodiment, the relationship of the above expression (3) is established if Q is the number of teeth 8 and N is the number of salient poles 32 facing Q teeth 8. Further, the number N of salient poles 32 need not be a natural number.

In this example, Q is 12 and N is 11 as in embodiment 1, and therefore the above formula (2) is satisfied. Thus, in this example, the motor 1 is driven at a speed of 5: the 6-series polar trough combinations operate.

In the motor 1 as described above, the salient pole members 3 are arranged in the linear direction, the plurality of teeth 8 are arranged in the linear direction along the salient pole members 3, and the armature 2 is movable in the linear direction in which the plurality of teeth 8 are arranged with respect to the salient pole members 3, so that the salient pole members 3 are used as the conveyance path in which the armature 2 moves, and thus the permanent magnets 5 do not need to be provided in the conveyance path of the linear motor. This can suppress an increase in the manufacturing cost of the motor 1 as a linear motor.

That is, in a typical linear motor, an iron core provided with a permanent magnet is used as a conveyance path for conveying an armature as a movable element. Therefore, the permanent magnet is required in proportion to the conveying distance of the movable element, and in the case of long-distance conveyance, the conveying path becomes long, and therefore the amount of use of the permanent magnet increases, and the cost increases. In contrast, in the present embodiment, since the armature 2 includes the permanent magnet 5 and the salient pole member 3 used as the transport path is made of only iron, an increase in the amount of the permanent magnet 5 used can be suppressed even if the transport path is lengthened. Therefore, in the present embodiment, even in the case of long-distance conveyance, an increase in the manufacturing cost of the motor 1 can be suppressed. Further, an amplifier that can supply power to the armature 2 may be mounted on the armature 2.

In the present embodiment, Q is 12 and N is 11, so that the relationship between the pitch P1 of the teeth 8 and the pitch P2 of the salient poles 32 can satisfy expression (2), and the cogging thrust of the motor 1, which is a linear motor, can be reduced. In addition, in conventional 2: in the case of 3 series, the winding factor is 0.866, whereas in embodiment 5: the winding factor becomes 0.933 for the 6-series pole-slot combination. Therefore, in the present embodiment, the winding factor is similar to the conventional 2: the thrust of the motor 1, which is a linear motor, can be improved more than in the case of the 3-series motor.

In the above example, the permanent magnets 5 are exposed on the surface of the armature core 4 on the salient pole member 3 side and on the surface of the armature core 4 on the side opposite to the salient pole member 3 side, but the permanent magnets 5 may be exposed on the surface of the armature core 4 on the salient pole member 3 side, and the permanent magnets 5 may be covered with the core holder 7 on the surface of the armature core 4 on the side opposite to the salient pole member 3 side.

In the above example, Q-12 and N-11 are applied to the linear motor, but Q-12 and N-1 may be applied to the linear motor as in embodiment 3.

Embodiment 5.

Fig. 6 is a structural diagram showing a motor according to embodiment 5 of the present invention. In the present embodiment, Q is 12 and N is 13. Thus, in the present embodiment, the relationship between P1 and P2 satisfies the above expression (2).

Therefore, in the present embodiment, the magnetomotive force of the 6-pole pair generated by the 12 permanent magnets 5 is modulated by the 13 salient poles 32 to generate the magnetic flux of the 7-pole pair. Therefore, in this example, the motor 1 operates with 14 poles and 12 slots. That is, in this example, the motor 1 is driven at a speed of 7: the 6-series polar trough combinations operate. The other structure is the same as embodiment 4.

As described above, in the motor 1 as a linear motor, even if Q is 12 and N is 13, the relationship between P1 and P2 can satisfy the formula (2). Thus, the ratio of 5: 6 series Large 7: the 6-series pole groove combination operates the motor 1, and the cogging thrust of the motor 1, which is a linear motor, can be further reduced. Further, since the number of the permanent magnets 5 per 1 pole can be reduced, magnetic saturation in the core print 7 is less likely to occur, and the radial thickness of the core print 7 can be reduced. Therefore, the winding area of the armature winding 6 can be enlarged, and the copper loss of the armature winding 6 can be reduced.

Embodiment 6.

Fig. 7 is a structural diagram showing a motor according to embodiment 6 of the present invention. In the present embodiment, Q is 12 and N is 11.2.

For example, the following expression (5) may be satisfied in order to operate the motor 1 as a 10-pole 12-slot when Q is 12, and the following expression (6) may be satisfied in order to operate the motor 1 as a 14-pole 12-slot when Q is 12.

5/6＜(P1/P2)＜1…(5)

1＜(P1/P2)＜7/6…(6)

In the present embodiment, Q is 12 and N is 11.2, and therefore the relationship between P1 and P2 satisfies expression (5) in accordance with expression (3). The other structure is the same as embodiment 4.

As described above, even if the value of N is not a natural number, the motor 1 can be operated without any problem. Accordingly, for example, even when the operation accuracy of the salient pole members 3 is poor, the cogging thrust of the motor 1, which is a linear motor, can be reduced, and the motor 1 can be operated without any problem.

In the above example, the motor 1 is a linear motor, but the cogging torque of the motor 1 can be reduced similarly even if the motor 1 is a rotary motor.

Embodiment 7.

Fig. 8 is a structural diagram showing a motor according to embodiment 7 of the present invention. In the motor 1 as a linear motor, the projections 11 are provided on both side end portions of the armature core 4 in the linear direction in which the teeth 8 are arranged. Each boss 11 projects from the core print 7 toward the salient pole members 3, opposing the salient pole members 3. Further, each boss 11 is disposed apart from the teeth 8 in the linear direction in which the teeth 8 are arranged. The armature winding 6 is not provided in each boss 11. Each boss 11 is made of the same material as the core print 7, and is formed integrally with the core print 7. In this example, Q is 12 and N is 11. Therefore, in the present example, the relationship between P1 and P2 satisfies the above expression (2). The other structure is the same as embodiment 4.

In the motor 1 as described above, since the convex portions 11 are provided at the end portions on both sides of the armature core 4 in the linear direction in which the teeth 8 are arranged, the cogging thrust of the motor 1 as a linear motor can be further reduced. In addition, the thrust of the motor 1 can be improved.

In the above example, the projections 11 are provided at both side end portions of the armature core 4, but the projections 11 may be provided only at one side end portion of the armature core 4 in the linear direction in which the teeth 8 are arranged.

Embodiment 8.

Fig. 9 is a structural diagram showing a motor according to embodiment 8 of the present invention, in which each tooth 8 located at both end portions of armature core 4 in the linear direction in which each tooth 8 is arranged is an end tooth 8a, each tooth 8 other than end tooth 8a is an intermediate tooth 8b, and the shape of end tooth 8a is different from the shape of intermediate tooth 8 b. The intermediate teeth 8b have the same shape.

The relationship between the pitch P1 of the teeth 8 and the pitch P2 of the salient poles 32 satisfies the above expression (1) or (2). The relationships of P1, P2, and Q, N satisfy the above expression (3). The pitch P1 of the teeth 8 applied to equations (1) to (6) is set by the distance between the intermediate portion teeth 8b on the pitch reference plane. The other structure is the same as embodiment 4.

In the motor 1 as described above, the shapes of the end teeth 8a are different from the shapes of the intermediate teeth 8b, and therefore, the cogging thrust of the motor 1, which is a linear motor, can be further reduced by adjusting the shapes of the end teeth 8 a. That is, unlike a rotary motor, in the motor 1 which is a linear motor, the armature 2 is not endless, but an end portion of the armature 2 is present in a linear direction in which the armature 2 moves, and the structure is discontinuous. Therefore, since the end portion of the armature 2 is present and has a discontinuous structure, the cogging component is added to the thrust force of the motor 1. In the present embodiment, since the end teeth 8a are different in shape from the intermediate teeth 8b, the cogging component due to the discontinuity of the armature 2 can be suppressed, and the cogging thrust of the motor 1 as a linear motor can be further reduced. In addition, the thrust of the motor 1 can be improved.

In the above example, the shape of each of the end teeth 8a located at the end portions on both sides of the armature core 4 is different from the shape of the intermediate teeth 8b, but the shape of the end teeth 8a located only at the end portion on one side of the armature core 4 may be different from the shape of the intermediate teeth 8 b.

In the above example, although the cogging thrust of the motor 1 is reduced by making the end teeth 8a different in shape from the intermediate teeth 8b, the cogging thrust of the motor 1 can be reduced by making the distance between the end teeth 8a and the adjacent intermediate teeth 8b of the end teeth 8a, that is, the pitch of the end teeth 8b, and the distance between the intermediate teeth 8b, that is, the pitch of the intermediate teeth 8b, different from each other, thereby suppressing the cogging component caused by the discontinuity of the armature 2.

Embodiment 9.

Fig. 10 is a structural diagram showing a motor according to embodiment 9 of the present invention. In this example, as in embodiment 8, the teeth 8 located at the end portions on both sides of the armature core 4 in the linear direction in which the teeth 8 are arranged are end teeth 8a, and the teeth 8 other than the end teeth 8a are intermediate teeth 8 b. In this example, the intermediate portion teeth 8b located adjacent to the end portion teeth 8a among the intermediate portion teeth 8b are end portion adjacent teeth 8 c. If each tooth 8 is defined as above, the shape of each end-adjacent tooth 8c is different from the shape of each other tooth 8, that is, the shape of each of the intermediate teeth 8b and the end teeth 8a other than the end-adjacent tooth 8 c. In this example, the shape of the permanent magnet 5 accommodated in the end-adjacent tooth 8c is different from the shape of the permanent magnet 5 accommodated in the other tooth 8 than the end-adjacent tooth 8c, and thus the shape of each end-adjacent tooth 8c is different from the shape of the other tooth 8. In this example, the thickness of the permanent magnet 5 housed in the end-adjacent tooth 8c is larger than the thickness of the permanent magnet 5 housed in the other tooth 8. The intermediate teeth 8b and the end teeth 8a other than the end adjacent teeth 8c have the same shape. The other structure is the same as embodiment 8.

In the motor 1 as described above, the shape of the end adjacent teeth 8c located adjacent to the end teeth 8a is different from the shape of the other teeth 8 other than the end adjacent teeth 8c, and therefore the cogging component due to the discontinuity of the armature 2 can be suppressed, and the cogging thrust of the motor 1 can be further reduced. In addition, the thrust of the motor 1 can be improved.

In the above example, the shape of each of the end-adjacent teeth 8c located on both sides of the armature core 4 is different from the shape of the other teeth 8, but only the shape of the end-adjacent tooth 8c located on one side of the armature core 4 may be different from the shape of the other teeth 8.

Embodiment 10.

Fig. 11 is a structural diagram showing a motor according to embodiment 10 of the present invention. In the present embodiment, the number Q of teeth 8 is set to a value satisfying the following expression (7), and the number N of salient poles 32 opposing the Q teeth 8 is set to a value satisfying the following expression (8).

Q＝3·k·m…(7)

N＝(3·k±0.5)·m…(8)

Where k is a natural number of 2 or more, that is, k is 2, 3, 4 …, and m is a natural number of 1 or more, that is, m is 1, 2, 3 ….

In this example, when k is 2, m is 2, Q is 12, and N is 11.

Fig. 12 is a table showing combinations of values of k, m, and Q when Q is 3 · k · m in the motor according to embodiment 10 of the present invention. Fig. 13 is a table showing combinations of values of k, m, and N when N is (3 · k +0.5) · m in the motor according to embodiment 10 of the present invention. Fig. 14 is a table showing combinations of values of k, m, and N when N is (3 · k-0.5) · m in the motor according to embodiment 10 of the present invention. Fig. 15 is a table showing combinations of values of k, m, and a pole groove combination when N is (3 · k +0.5) · m in the motor according to embodiment 10 of the present invention. Fig. 16 is a table showing combinations of values of k, m, and a pole groove combination when N is (3 · k-0.5) · m in the motor according to embodiment 10 of the present invention. In fig. 15 and 16, the number of poles is denoted by "P" and the number of teeth, that is, the number of slots is denoted by "S", as the value of the combination of the pole and the slot. For example, when the number of poles is 5 and the number of teeth is 6, "5P 6S" is used as the value of the combination of the pole grooves.

In the present embodiment, Q and N are set in accordance with the values of k and m in the ranges of k > 1 and m.gtoreq.1, as shown in FIGS. 12 to 16. The other structure is the same as embodiment 1.

In the motor 1 as described above, since Q satisfies expression (7) and N satisfies expression (8), the fundamental wave of the torque can be increased, and the torque of the motor 1 can be increased. Further, since k > 1, the winding coefficient is improved to increase the torque, and the cogging torque due to the pole-slot combination can be reduced.

In addition, since the equation (7) and the equation (8) satisfy the condition that m is 2, the cogging torque generated by the action of the salient pole members 3 and the permanent magnets 5 can be cancelled out between the teeth 8. This can further suppress cogging torque.

In the motor 1, when N is (3 · k-0.5) · m, the fundamental wave of the magnetic flux density of the air gap existing between the armature core 4 and the salient pole member 3 is improved as compared with the case where N is (3 · k +0.5) · m. Therefore, the number of teeth 8 and the number of salient poles 32 are set so as to satisfy Q ═ 3 · k · m and N ═ 3 · k-0.5) · m, whereby the torque of the motor 1 can be further increased.

Embodiment 11.

Fig. 17 is a structural diagram showing a motor according to embodiment 11 of the present invention. In the present embodiment, Q and N satisfy the above-described formulas (7) and (8), and m is 1 and k > 1 in the formulas (7) and (8). In this example, m is 1 and k is 2. Thus, in this example, Q is 6 and N is 5.5. The other structure is the same as embodiment 4.

In the motor 1 described above, Q and N satisfy the above-described equations (7) and (8), and m is 1 and k > 1 in the equations (7) and (8), so that the number of teeth 8 and permanent magnets 5 in each pole-groove combination can be minimized. For example, the combination of pole grooves of "10P 12S" may be "5P 6S", or the combination of pole grooves of "16P 18S" may be "8P 9S". Thus, when the volume of the motor 1 is constant, the thickness of the permanent magnet 5 can be maximized in each pole-slot combination, and the magnetic flux flowing from the permanent magnet 5 to the salient pole member 3 can be increased. Therefore, the induced voltage in the armature 2 can be increased, and the thrust of the motor 1 can be increased.

In this example, since m is 1, k is 2, Q is 6, and N is 5.5, the ratio of m to k can be set to 5: in the motor 1 operated by the 6-series pole groove combination, the number of the permanent magnets 5 is minimized. This makes it possible to set the ratio between 5: in the 6-series pole groove combination, the thickness of the permanent magnet 5 is maximized, and the magnetic flux density of the air gap can be increased, thereby increasing the thrust of the motor 1 as a linear motor.

In addition, when N is (3 · k-0.5) · m, the fundamental wave of the magnetic flux density of the air gap can be improved as compared with the case where N is (3 · k +0.5) · m. Thus, the thrust of the motor 1, which is a linear motor, can be further increased by satisfying N ═ 3 · k-0.5) · m.

In the above example, the configuration in which Q and N satisfy the above equations (7) and (8) and m is 1 and k > 1 in the equations (7) and (8) is applied to the linear motor, but the configuration in which Q and N satisfy the above equations (7) and (8) and m is 1 and k > 1 in the equations (7) and (8) may be applied to the rotary motor. As described above, the thickness of the permanent magnet 5 can be maximized in each pole groove combination, and the torque of the rotary electric motor can be increased.

Embodiment 12.

Fig. 18 is a structural diagram showing a motor according to embodiment 12 of the present invention. In the present embodiment, Q and N satisfy the above-described formulas (7) and (8), and m is 2 and k > 1 in the formulas (7) and (8). In this example, m is 2 and k is 2. Thus, in this example, Q is 12 and N is 11.

If m is 2 in equations (7) and (8), a cogging torque component 1f generated by the action of the salient pole members 3 and the permanent magnets 5, that is, a cogging torque component occurring at the same period as the fluctuation of the air gap, is generated between the teeth 8 in a direction of canceling out each other. In fig. 18, numbers 1 to 12 (numbers circled by round frames) continuing in the linear direction for the sake of convenience of assignment to the respective teeth 27 are shown as tooth numbers.

Fig. 19 is a vector diagram showing the 1f component of the cogging torque produced by each tooth 8 of fig. 18. In fig. 19, vectors of 1f components of the cogging torque individually generated in each tooth 8 in fig. 18 are collectively represented by tooth numbers 1 to 12. As shown in fig. 19, it is understood that if the 1f components of the cogging torque generated in each of the teeth 8 of the tooth numbers 1 to 12 are added, the resultant vector of the 1f components of the cogging torque becomes substantially 0. The other structure is the same as embodiment 11.

In the motor 1 described above, Q and N satisfy the above-described equations (7) and (8), and m is 2 and k > 1 in the equations (7) and (8), so that the 1f components of the cogging torque generated in the teeth 8 can be cancelled out. This can further reduce the cogging torque of the motor 1.

Embodiment 13.

Fig. 20 is a structural diagram showing a motor according to embodiment 13 of the present invention. In the present embodiment, Q and N satisfy the above-described formulas (7) and (8), and m is 4 and k > 1 in the formulas (7) and (8). In this example, m is 4, k is 2, Q is 24, and N is 22. In this example, the motor 1 is a rotary motor.

If m is 4 in equations (7) and (8), the shape of the salient pole member 3 as viewed along the axis a is symmetrical on a straight line passing through the axis a. If the expressions (7) and (8) satisfy the condition that m is 4, the combination of the pole grooves when viewed along the axis a is symmetrical with respect to any of the 1 st and 2 nd straight lines that pass through the axis a and are orthogonal to each other. The other structure is the same as embodiment 10.

In the motor 1 as described above, Q and N satisfy the above-described equations (7) and (8), and m is 4 and k > 1 in the equations (7) and (8), so that the symmetry of the shape of the salient pole member 3 and the symmetry of the pole-slot combination of the motor 1 can be ensured. This can reduce vibration and noise of the motor 1.

In addition, since the symmetry of the induced voltage of the armature 2 can be ensured, the connection wires of the plurality of armature windings 6 can be connected in parallel by 2. When the connection lines of the plurality of armature windings 6 are a plurality of parallel connection lines, the armature windings 6 of the same phase that are close to each other are connected in series to form a plurality of sets of armature winding series units of the same phase, and the plurality of sets of armature winding series units of the same phase are connected in parallel. In a motor in which a plurality of sets of armature winding series units of the same phase are wired in parallel, if n is a natural number of 2 or more, the relationship of m being 2 · n is established, and the parallel number C of the armature winding series units of the same phase becomes a divisor other than 1 of n. When the parallel number C of the armature winding series units of the same phase is a divisor of n other than 1, the number of armature windings 6 connected in series in 1 armature winding series unit is Q/(3 · C). This improves the balance of the induced voltage, and reduces torque ripple, vibration, and noise of the motor 1.

Embodiment 14.

Fig. 21 is a structural diagram showing a motor according to embodiment 14 of the present invention. In the present embodiment, Q and N satisfy the above-described formulas (7) and (8), and m is 2 and k is 2 in the formulas (7) and (8). Thereby, Q is 12, N is 11, or 13. Therefore, when N is 11, the motor 1 operates in a 10-pole 12-slot mode, and when N is 13, the motor 1 operates in a 14-pole 12-slot mode. In this example, the motor 1 is a rotary motor.

Considering the balance among the air gap G, the thickness D of the permanent magnet 5, and the winding coefficient, when m is 2 and k is 2 in equations (7) and (8), the air gap G is 2mm to 4mm, and the ratio of the circumferential length D of the outer circumferential surface 4a of the armature core 4 to the thickness D of each permanent magnet 5 is (37 to 45): 1, whereby the induced voltage of the armature 2 becomes maximum. The other structure is the same as embodiment 10.

In the motor 1 described above, Q and N satisfy the above-described equations (7) and (8), and m is 2 and k is 2 in the equations (7) and (8), so that the induced voltage of the armature 2 can be increased by adjusting the sizes of the air gap, the armature core 4, and the permanent magnet 5 in consideration of the balance between the air gap G, the thickness d of the permanent magnet 5, and the winding coefficient. This can reduce the cogging torque of the motor 1 as a rotary motor.

Embodiment 15.

Fig. 22 is a structural diagram showing a motor according to embodiment 15 of the present invention. In the present embodiment, Q and N satisfy the above-described formulas (7) and (8), and m and k satisfy 2 and 2 in the formulas (7) and (8), as in embodiment 14. Thereby, Q is 12, N is 11, or 13. Therefore, when N is 11, the motor 1 operates in a 10-pole 12-slot mode, and when N is 13, the motor 1 operates in a 14-pole 12-slot mode. In this example, the motor 1 is a linear motor.

Considering the balance among the air gap G, the thickness D of the permanent magnet 5, and the winding coefficient, when m is 2 and k is 2 in equations (7) and (8), the air gap G is 2mm to 4mm, and the ratio of the total linear length D of the armature core 4 to the thickness D of each permanent magnet 5 is (37 to 45): 1, whereby the induced voltage of the armature 2 becomes maximum. The other structure is the same as embodiment 11.

In the motor 1 as described above, Q and N satisfy the above-described equations (7) and (8), and m is 2 and k is 2 in the equations (7) and (8), and therefore, the sizes of the air gap G, the armature core 4, and the permanent magnet 5 are adjusted in consideration of the balance between the air gap G, the thickness d of the permanent magnet 5, and the winding coefficient, whereby the induced voltage of the armature 2 can be increased, and the cogging thrust of the motor 1 as a linear motor can be reduced. That is, even if the motor 1 is a linear motor, the same effect as that of a rotary motor can be obtained.

In embodiments 14 and 15, although m is 2 in equations (7) and (8), if k is 2, m is a natural number of 1 or 3 or more, and the cogging torque or the cogging thrust of the motor 1 can be reduced.

Description of the reference numerals

1 motor, 2 armature, 3 salient pole component, 4 armature core, 5 permanent magnet, 6 armature winding, 8 teeth and 32 salient pole.

Claims

1. An electric motor, comprising:

an armature having an armature core having a plurality of teeth arranged adjacent to each other, a plurality of permanent magnets housed in the plurality of teeth, and a plurality of armature windings provided in the plurality of teeth; and

a salient pole member having 1 or more salient poles modulating magnetomotive force generated by the plurality of permanent magnets, the salient poles being disposed in a state of facing the teeth,

the armature and the salient pole member are relatively movable in a direction in which the plurality of teeth are arranged,

each of the permanent magnets housed in 2 adjacent teeth is arranged so that the same magnetic poles face each other,

if the pitch of the teeth is set to P1 and the pitch of the salient poles is set to P2, it is satisfied

(P1/P2) < 1/6, or

5/6＜(P1/P2)＜7/6，

If the number of the teeth is set to Q, the number of the salient poles opposing Q of the teeth is set to N,

when k is a natural number of 2 or more and m is a natural number of 1 or more, the following conditions are satisfied

Q is 3. k.m, and

N＝(3·k±0.5)·m，

supplying a current of three phases to the plurality of armature windings,

satisfies k-2 and m-2,

the plurality of armature windings are arranged on the teeth so as to generate a magnetic flux having the same number of pole pairs as that of a magnetic flux modulated by the salient pole by the magnetomotive force generated by the plurality of permanent magnets, that is, 5 pole pairs or 7 pole pairs.

2. The motor according to claim 1, wherein,

if the pitch of the permanent magnets is set to P3, the following condition is satisfied

5＜P1/P3＜10。

3. The motor according to claim 1 or 2,

supplying a current of three phases to the plurality of armature windings,

if the relationship between the number of magnetic poles formed by the plurality of armature windings and the number of teeth is taken as the number of magnetic poles: the number of teeth is shown by the combination of the pole slots

The pole groove combination is [ (N-Q/2) multiplied by 2 ]: and Q.

4. The motor according to claim 1 or 2,

the number of the armature windings provided at each of the teeth is 12,

of the 12 armature windings disposed in the adjacent teeth, 4 armature windings are formed of U-phase armature windings U11, U12, U21, and U22, the other 4 armature windings are formed of V-phase armature windings V11, V12, V21, and V22, and the remaining 4 armature windings are formed of W-phase armature windings W11, W12, W21, and W22,

if + and-indicate that the directions of the electromagnetic fields generated by the armature windings are opposite to each other in the radial direction when the armature windings flow the current in the same direction, then

The armature windings are arranged in the teeth in the order of + U11, -U12, -V11, + V12, + W11, -W12, -U21, + U22, + V21, -V22, -W21, + W22, or + U11, -U12, -W11, + W12, + V11, -V12, -U21, + U22, + W21, -W22, -V21, + V22.

5. The motor according to claim 1 or 2,

a plurality of armature windings of the same phase are connected in series to constitute a plurality of sets of armature winding series parts of the same phase,

the multiple groups of armature windings in the same phase are connected in series and connected in parallel,

if n is a natural number of 2 or more, the relationship of m 2 · n holds,

the parallel number C of the series-connected parts of the plurality of sets of armature windings in the same phase is a divisor other than 1 of n,

the number of the armature windings connected in series in the armature winding series connection unit is Q/(3 · C).

6. The motor according to claim 1 or 2,

the salient pole members are arranged in a linear direction,

the plurality of teeth are arranged in the linear direction,

the armature is movable relative to the salient pole member in the linear direction.

7. The motor according to claim 6, wherein,

if the teeth located adjacent to the end teeth in the linear direction among the plurality of teeth are set as end-adjacent teeth

The shape of the permanent magnet accommodated in the end-adjacent tooth is different from the shape of the permanent magnet accommodated in the teeth other than the end-adjacent tooth.