WO2023203646A1

WO2023203646A1 - Electric motor

Info

Publication number: WO2023203646A1
Application number: PCT/JP2022/018200
Authority: WO
Inventors: 優 ▲高▼村; 迪廣谷; ザイニアリフ; 功太郎榊原; 健太郎橋本
Original assignee: 三菱電機株式会社
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2023-10-26
Also published as: DE112022004572T5; JP7191279B1; CN118160193A; JPWO2023203646A1; KR20240096775A

Abstract

An electric motor (50) comprises a magnetic field and an armature. The armature has a core back (11), a plurality of teeth (12), and a plurality of coils (13). The plurality of teeth (12) include: first teeth, which are teeth (12) to which only coils (13) of one phase are attached; and second teeth, which are teeth (12) to which coils (13) of a plurality of phases are attached. Each of the plurality of coils (13) is arranged so as not to straddle a slot. When the quantity of teeth (12) in the armature is denoted by N, and a greatest common devisor between the quantity of teeth (12) N and the number of magnetic poles of the magnetic field in a range opposing the N teeth (12) is denoted by C, a quantity of C sections each configured by a quantity of N/C teeth (12) are arranged in an advancing direction. In a section, two second teeth are arranged in succession in the advancing direction, or the number of second teeth included in the section is one.

Description

Electric motor

The present disclosure relates to an electric motor having teeth and a coil attached to the teeth.

Conventionally, when the number of magnetic poles of the rotor is P, the number of teeth of the stator is N, and the greatest common divisor of P and N is C, N/C = P/C ± 1, and N/C is other than a multiple of 3. An electric motor is known in which the cogging torque can be reduced by setting the value to an integer. Regarding such electric motors, Patent Document 1 states that the number of turns in a tooth to which a coil for only one of three phases is attached is the number of turns for each phase in each tooth to which coils for multiple phases out of three phases are attached. It is disclosed that the torque ripple can be reduced by making the torque ripple different from the sum of . The electric motor shown in Patent Document 1 has a first tooth to which only one phase coil is attached, and a second tooth to which multiple phase coils are attached.

International Publication No. 2019/008848

According to the technology of Patent Document 1, the stator includes two or more second teeth, and the first tooth is arranged between the second teeth. The larger the number of second teeth, that is, the larger the number of coils, the more dispersed the phase of the generated magnetic flux becomes, and the lower the distributed winding coefficient becomes. Further, by disposing the first tooth between the second teeth, the phase difference between the magnetic fluxes generated in the coil becomes large, and the distributed winding coefficient becomes low. As the distributed winding coefficient becomes lower, the heat generated by the coil increases. Therefore, the technique disclosed in Patent Document 1 has a problem in that the coil generates a large amount of heat.

The present disclosure has been made in view of the above, and an object of the present disclosure is to obtain an electric motor that can reduce heat generation of a coil.

In order to solve the above-mentioned problems and achieve the objective, an electric motor according to the present disclosure includes a magnetic field and an armature that is disposed facing the magnetic field and is movable relative to the magnetic field. Be prepared. The armature includes a core back, a plurality of teeth each extending from the core back toward the field, and arranged in the direction of movement of the armature with respect to the field, and a plurality of teeth attached to the plurality of teeth. It has a coil. The plurality of teeth includes a first tooth that is a tooth to which only one phase coil is attached, and a second tooth that is a tooth to which a plurality of phase coils are attached. Each of the plurality of coils is arranged so as not to straddle a slot formed by adjacent teeth. The number of teeth of the armature is N, and the greatest common divisor of the number of teeth, N, and the number of magnetic poles of the field in the range facing the N teeth is C, and it is composed of N/C teeth. C sections are arranged in the traveling direction. In the section, two second teeth are arranged consecutively in the traveling direction, or the section includes one second tooth.

The electric motor according to the present disclosure has the effect of reducing heat generation of the coil.

A schematic diagram showing a schematic configuration of an electric motor system including an electric motor according to Embodiment 1. Cross-sectional view of the electric motor according to the first embodiment A diagram showing an example of the number of turns of the coil attached to each tooth in Embodiment 1. Cross-sectional view of an electric motor according to a comparative example of Embodiment 1 A diagram showing an example of the number of turns of the coil attached to each tooth in a comparative example of Embodiment 1. Vector diagram representing induced voltage in each coil of the electric motor according to Embodiment 1 Vector diagram showing induced voltage in each coil of the motor according to the comparative example of Embodiment 1 A diagram for explaining an increase in the distributed winding coefficient in the electric motor according to the first embodiment A diagram for explaining mutual inductance reduction by the electric motor according to the first embodiment Cross-sectional view of the electric motor according to the second embodiment A diagram showing an example of the number of turns of the coil attached to each tooth in Embodiment 2. Cross-sectional view of an electric motor according to a comparative example of Embodiment 2 A diagram showing an example of the number of turns of the coil attached to each tooth in a comparative example of Embodiment 2. Vector diagram showing induced voltage in each coil of the electric motor according to Embodiment 2 Vector diagram showing induced voltage in each coil of the motor according to the comparative example of Embodiment 2 A diagram for explaining an increase in the distributed winding coefficient in the electric motor according to the second embodiment Cross-sectional view of the electric motor according to Embodiment 3 Cross-sectional view of the electric motor according to Embodiment 4 A diagram showing an example of the number of turns of the coil attached to each tooth in Embodiment 4. A diagram for explaining an increase in distributed winding coefficient in the electric motor according to Embodiment 4 Cross-sectional view of the electric motor according to the fifth embodiment

Below, an electric motor according to an embodiment will be described in detail based on the drawings.

Embodiment 1.
FIG. 1 is a schematic diagram showing a schematic configuration of a motor system 100 including a motor 50 according to the first embodiment. The electric motor system 100 includes an electric motor 50, a guide 60 that is a linearly extending installation object, and a slider 70 that is movable along the guide 60.

The electric motor 50 has a mover 1 and a stator 2. The movable element 1 is arranged facing the stator 2. Stator 2 is a magnetic field. The mover 1 is an armature for obtaining thrust through interaction with a magnetic field. The movable element 1 faces the stator 2 with a gap interposed therebetween. The movable element 1 is fixed to a slider 70. The movable element 1 moves along the guide 60 together with the slider 70 due to the thrust generated by the interaction between the movable element 1 and the stator 2 . The movable element 1 is movable in a linear direction relative to the stator 2. That is, the mover 1 is movable relative to the stator 2. The electric motor 50 is a direct-acting motor that operates the movable element 1 in a linear direction. The double-headed arrow shown in FIG. 1 represents the direction in which the movable element 1 can move, that is, the direction in which the movable element 1 moves.

The stator 2 includes a stator core having a mounting seat 22 and a plurality of permanent magnets 21 provided on the surface of the mounting seat 22. Illustration of the stator core is omitted. Each permanent magnet 21 is attached to a mounting seat 22 on the surface of the stator core. The plurality of permanent magnets 21 are arranged in the direction in which the mover 1 moves.

FIG. 2 is a sectional view of the electric motor 50 according to the first embodiment. The cross section shown in FIG. 2 is a cross section that includes the moving direction of the movable element 1 and the direction in which the movable element 1 and the stator 2 face each other. The cross section of the stator 2 shown in FIG. 2 is a cross section of a portion of the stator 2 that faces the movable element 1.

The mover 1 has a mover core and a plurality of coils 13 attached to the mover core. The mover core includes a core back 11 extending in the moving direction of the mover 1 and a plurality of teeth 12 extending from the core back 11 toward the stator 2. In the first embodiment, the movable element 1 has five teeth 12. The five teeth 12 are lined up in the moving direction of the movable element 1. The field side tip of each tooth 12 has a straight shape. The slot in which the coil 13 is arranged is a portion adjacent to the teeth 12 in the moving direction of the movable element 1. Teeth 12 adjacent to each other constitute a slot. Each coil 13 is constructed by winding a conducting wire around the teeth 12 in a concentrated manner. That is, each of the plurality of coils 13 included in the movable element 1 is arranged so as not to straddle any slot.

In the first embodiment, four of the plurality of permanent magnets 21 arranged in the moving direction of the mover 1 face the five teeth 12. That is, the number of magnetic poles in the range facing the five teeth 12 in the moving direction of the movable element 1 is four.

A voltage is applied to the mover 1 from a three-phase AC power source. Illustration of the three-phase AC power supply is omitted. The number of teeth 12 of the mover 1 is N, and the greatest common divisor of N, which is the number of teeth 12, and the number of magnetic poles in the range facing the N teeth 12 is C. Hereinafter, the number of magnetic poles is the number of magnetic poles in the range facing the N teeth 12. In the first embodiment, the number of magnetic poles is 4, with N=5 and C=1. In the first embodiment, N/C is 5, which is an integer other than a multiple of 3. N is an integer other than a multiple of 3. By satisfying these conditions, the electric motor 50 can achieve the effect of reducing cogging torque.

In the first embodiment, each tooth 12 of the movable element 1 is assigned a tooth number for convenience. Teeth numbers t1, t2, t3, t4, and t5 are assigned to each tooth 12 from left to right in FIG. 2, respectively.

A three-phase coil 13 is attached to the five teeth 12. A -U phase coil 13 is attached to the teeth 12 at t1. A -V phase coil 13 is attached to the teeth 12 at t2. A +V phase coil 13 and a -W phase coil 13 are attached to the teeth 12 at t3. A +W phase coil 13 is attached to the teeth 12 at t4. A +U phase coil 13 is attached to the teeth 12 at t5. "+" and "-" represent the winding direction of the coil 13. Note that U-, V-, V+, W-, W+, and U+ shown in FIG. 2 represent -U phase, -V phase, +V phase, -W phase, +W phase, and +U phase, respectively.

Each of the teeth 12 t1, t2, t4, and t5 is a tooth 12 to which only a one-phase coil 13 is attached. Teeth 12 at t3 is a tooth 12 to which a two-phase coil 13 is attached. In this way, the plurality of teeth 12 of the mover 1 are a first tooth 12 to which only one phase coil 13 is attached, and a second tooth 12 to which a plurality of phase coils 13 are attached. Including teeth. Each tooth 12 at t1, t2, t4, and t5 is a first tooth. Teeth 12 at t3 is the second tooth. Each of the teeth 12 at t1 and the teeth 12 at t5, which are the teeth 12 located at the ends in the moving direction of the movable element 1, is a first tooth.

In the electric motor 50, C sections 10 each made up of N/C teeth 12 are arranged in the traveling direction. In the first embodiment, one section 10 composed of five teeth 12 is arranged in the traveling direction. Further, in the first embodiment, the number of second teeth included in the section 10 is one.

FIG. 3 is a diagram showing an example of the number of turns of the coil 13 attached to each tooth 12 in the first embodiment. FIG. 3 shows the number of turns of the coil 13 for each phase in each tooth 12 and the total number of turns of each tooth 12. The number of turns shown in FIG. 3 is the number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. The total number of turns shown in FIG. 3 is the total number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. That is, the number of turns of each tooth 12 and the total number of turns are expressed by the ratio to the number of turns of the entire movable element 1. Moreover, FIG. 3 shows the ratio of the number of series conductors for each phase to the number of series conductors in the entire movable element 1.

As shown in FIG. 3, the total number of turns in the teeth 12 at t3 is 0.12. Each of the teeth 12 at t2 and the teeth 12 at t4 is a first tooth adjacent to a second tooth. The total number of turns of 0.27 in each of the teeth 12 at t2 and the teeth 12 at t4 is greater than the total number of turns of 0.12 in the teeth 12 at t3. Thus, in section 10 of the first embodiment, the total number of turns of the coil 13 in the first tooth adjacent to the second tooth is greater than the total number of turns of the coil 13 in the second tooth.

Furthermore, each of the teeth 12 at t1 and the teeth 12 at t5 is a first tooth adjacent to a second tooth via one first tooth. The total number of turns of 0.17 in each of the teeth 12 at t1 and the teeth 12 at t5 is smaller than 0.27, which is the total number of turns in each of the teeth 12 at t2 and the teeth 12 at t4. In this way, in the section 10 of the first embodiment, the total number of turns of the coil 13 in the first tooth adjacent to the second tooth via one first tooth is This is less than the total number of turns of the coil 13 in one tooth.

Here, the configuration of an electric motor according to a comparative example of Embodiment 1 will be described. FIG. 4 is a sectional view of the electric motor 51 according to a comparative example of the first embodiment. FIG. 5 is a diagram showing an example of the number of turns of the coil 13 attached to each tooth 12 in a comparative example of the first embodiment. Similar to the electric motor 50 shown in FIG. 2, the mover 1 has five teeth 12. A +U phase coil 13 is attached to the teeth 12 at t1. A +V phase coil 13 and a -U phase coil 13 are attached to the teeth 12 at t2. A -V phase coil 13 is attached to the teeth 12 at t3. A +V phase coil 13 and a -W phase coil 13 are attached to the teeth 12 at t4. A +W phase coil 13 is attached to the teeth 12 at t5.

Section 10 of electric motor 51 has two second teeth. In section 10 of electric motor 51, teeth 12 of t3, which are first teeth, are arranged between teeth 12 of t2, which are second teeth, and teeth 12 of t4, which are second teeth. . The number of coils 13 in section 10 of electric motor 51 is one more than the number of coils 13 in section 10 of electric motor 50 shown in FIG. Further, in the section 10 of the electric motor 51, there is no first tooth adjacent to a second tooth via one first tooth.

FIG. 6 is a vector diagram showing the induced voltage in each coil 13 of the electric motor 50 according to the first embodiment. FIG. 7 is a vector diagram showing the induced voltage in each coil 13 of the electric motor 51 according to the comparative example of the first embodiment. In FIGS. 6 and 7, vectors indicated by solid arrows represent the amplitude and phase of the induced voltage in each coil 13 disposed on the teeth 12. In each vector diagram of FIGS. 6 and 7, a phase angle of 360 degrees is defined as twice the pitch of the permanent magnets 21. Hereinafter, a vector representing the amplitude and phase of the induced voltage in the coil 13 will be referred to as an induced voltage vector. "t1_U-" shown in FIG. 6 is the induced voltage vector of the -U phase coil 13 attached to the teeth 12 at t1. In FIGS. 6 and 7, the induced voltage vector of each coil 13 is expressed in the same manner as in the case of "t1_U-". The vector indicated by the broken line arrow is the induced voltage vector of each phase, and is a composite vector obtained by combining the induced voltage vectors of each coil 13 for each phase.

The phase difference between adjacent teeth 12 is expressed as {360×(P/2)/N} degrees using P, which is the number of magnetic poles, and N, which is the number of teeth 12. For example, in the electric motor 50, the phase difference between the teeth 12 at t1 and the teeth 12 at t2 is 360°×(4/2)/5=144°. Each tooth 12 of the electric motor 50 is arranged so that the phase difference between adjacent teeth 12 is 144 degrees. Note that the phase of the induced voltage when the winding direction is "-" is 180 degrees ahead of the phase of the induced voltage when the winding direction is "+".

By combining the induced voltage vectors of each coil 13 for each phase, the induced voltage vector of each phase is obtained. k _d,phase, which is the distributed winding coefficient k _d of each phase, is defined by the following equation (1).

N _C represents the total number of coils 13 in each phase. N _phase,i (i=1,..., N _C ) represents the number of turns of each coil 13. θ _phase,i represents the phase of the induced voltage vector in each coil 13. θ _phase represents the phase of the composite vector of each phase. θ _phase is defined by the following equation (2).

For example, the U-phase composite vector in the electric motor 50 is a composite vector of "t1_U-" and "t5_U+". If the phase of "t1_U+" is 0 degrees, the phase θ _U,1 of "t1_U-" is 180 degrees. θ _U,2 , which is the phase of “t5_U+”, is calculated as 144°×(5−1)=576°. When θ _U,2 is converted into an angle from 0 degrees to 360 degrees, θ _U,2 is 216 degrees. Since the number of turns of the coil 13 in "t1_U-" and the number of turns in the coil 13 in "t5_U+" are equal to each other, θ _U , which is the phase of the U-phase composite vector, is (θ _U,1 + θ _U,2 )/ It is calculated as 2=(180°+216°)/2=198°.

k _d,U, which is the distributed winding coefficient k _d of the U phase, is calculated as shown in the following equation (3) by substituting values for each variable in equation (1). N _U,1 is the number of turns of the coil 13 of "t1_U-" which is the coil 13 constituting the U phase. N _U,2 is the number of turns of the coil 13 of "t5_U+" which is the coil 13 constituting the U phase.
k _d,U = {N _U,1 ×cos (180°-198°) + N _U,2 ×cos (216°-198°)}/(N _U,1 +N _U,2 ) ... (3)

Each of k _d,V, which is the distributed winding coefficient k _d of the V phase, and k _d,W, which is the distributed winding coefficient k _d of the W phase, can be obtained by the same calculation as in the case of k _d,U. . k _d,UVW, which is the sum of the distributed winding coefficients k _d of all phases, which are the U phase, V phase, and W phase, is calculated by the following equation (4).
k _d,UVW = (k _d,U +k _d,V +k _d,W )/3...(4)

FIG. 8 is a diagram for explaining an increase in the distributed winding coefficient in the electric motor 50 according to the first embodiment. FIG. 8 shows a bar graph representing the value of the distributed winding coefficient of the electric motor 51 according to the comparative example and a bar graph representing the value of the distributed winding coefficient of the electric motor 50 according to the first embodiment. The value of the distributed winding coefficient is a value standardized based on the value of the distributed winding coefficient of the electric motor 51. That is, the value of the distributed winding coefficient is expressed by the ratio to the value of the distributed winding coefficient of the electric motor 51.

In the case of the first embodiment shown in FIG. 6, there are two U-phase coils 13, two V-phase coils 13, and two W-phase coils 13. In the case of the comparative example shown in FIG. 7, there are two U-phase coils 13, three V-phase coils 13, and two W-phase coils 13. In the first embodiment, since the number of coils 13 is one less than in the comparative example, it is possible to obtain the same amplitude as in the comparative example with a smaller number of turns than in the comparative example. Therefore, in the first embodiment, the distributed winding coefficient can be increased more than in the comparative example.

By employing the coil arrangement shown in FIG. 2 and the number of turns shown in FIG. 3, the electric motor 50 increases the distributed winding coefficient compared to the comparative example having the coil arrangement shown in FIG. 4 and the number of turns shown in FIG. You can get the desired effect.

The electric motor 50 does not have a configuration in which the first teeth are arranged between the second teeth. Since the electric motor 50 can have a higher distributed winding coefficient than that of the comparative example, the heat generation of the coil 13 in the movable element 1 can be reduced.

The electric motor 50 can reduce the difference in induced voltage and inductance of each phase by setting the total number of turns of each tooth 12 as described above. Thereby, the electric motor 50 has the effect of reducing the difference in terminal voltage of the electric motor 50. Further, since the electric motor 50 can reduce the difference in the total number of turns of each phase, it can reduce the difference in resistance values. Thereby, the electric motor 50 has the effect of reducing local heat generation of the coil 13.

FIG. 9 is a diagram for explaining mutual inductance reduction by the electric motor 50 according to the first embodiment. FIG. 9 shows a bar graph representing the mutual inductance value of the electric motor 51 according to the comparative example and a bar graph representing the mutual inductance value of the electric motor 50 according to the first embodiment. The mutual inductance value is a value standardized based on the mutual inductance value of the electric motor 51. That is, the value of the mutual inductance is expressed by the ratio to the value of the mutual inductance of the electric motor 51. By employing the coil arrangement shown in FIG. 2 and the number of turns shown in FIG. 3, the electric motor 50 can reduce mutual inductance compared to the comparative example having the coil arrangement shown in FIG. 4 and the number of turns shown in FIG. Effects can be obtained.

Note that the electric motor 50 is not limited to one in which the number of turns of the coil 13 attached to each tooth 12 is set as shown in FIG. The number of turns of the tooth 12 to which the two-phase coil 13 is attached need not be extremely large compared to other teeth 12, and the combination of the number of turns of each tooth 12 may be different from the case shown in FIG. 3. In the electric motor 50, even if the combination of the number of turns of each tooth 12 is different from that shown in FIG. 3, the same effect as when the number of turns of each coil 13 is set as shown in FIG. 3 can be obtained.

The order of arrangement of the coils 13 on the teeth 12 to which the coils 13 of a plurality of phases are attached is arbitrary. The order of the +V phase coil 13 and the -W phase coil 13 in the teeth 12 at t3 shown in FIG. 2 may be reversed from that shown in FIG. Further, the arrangement of the coils 13 in the plurality of teeth 12 may be as long as the order of the phases in the moving direction of the movable element 1 is the same as that shown in FIG. 2 . As long as the order of the phases is the same as in the case shown in FIG. 2, the phase located at the end in the traveling direction may be any phase.

In the first embodiment, the movable element 1 has a configuration that satisfies N=5 and C=1. That is, the movable element 1 has a configuration in which one section 10 composed of five teeth 12 is arranged in the traveling direction. In the electric motor 50, a plurality of sections 10 may be arranged in the traveling direction. That is, the movable element 1 may have a configuration including a plurality of sections 10. In this case, C is a natural number greater than 1. Even when C is a natural number larger than 1, the electric motor 50 can obtain the above-mentioned effects in the same way as when C is 1.

In the first embodiment, the movable element 1 has a configuration in which a single section 10 or a plurality of sections 10 are arranged in the traveling direction. In addition, auxiliary teeth, which are teeth 12 without coils 13, may be attached to each of the ends of the mover 1 in the moving direction. Even when auxiliary teeth are attached to both ends of the movable element 1 in the direction of movement, the electric motor 50 can obtain the same effect as when no auxiliary teeth are attached.

Each of the plurality of teeth 12 is not limited to having a straight tip portion on the field side. A protrusion or a depression oriented in the traveling direction may be formed at the tip of the tooth 12 on the field side. Even when the teeth 12 are formed with protrusions or depressions, the electric motor 50 can obtain the same effect as when the teeth 12 are straight.

In the first embodiment, a configuration was described in which a plurality of permanent magnets 21 are attached to the mounting seat 22 on the surface of the stator core, but in the electric motor 50, a plurality of permanent magnets 21 are embedded inside the stator core. It may be a configuration. Even when the plurality of permanent magnets 21 are embedded inside the stator core, the electric motor 50 can obtain the same effect as when the plurality of permanent magnets 21 are provided on the surface of the stator core.

According to the first embodiment, in the electric motor 50, C sections 10 each including N/C teeth 12 are arranged in the traveling direction, and the second tooth in the section 10 is one. The electric motor 50 can reduce heat generation of the coil 13 in the movable element 1 by increasing the distributed winding coefficient. As described above, the electric motor 50 has the effect of reducing heat generation of the coil 13.

Embodiment 2.
FIG. 10 is a sectional view of the electric motor 52 according to the second embodiment. In the second embodiment, the arrangement of the teeth 12 and the coil 13 in the movable element 1 is different from that in the first embodiment. In Embodiment 2, the same components as in Embodiment 1 described above are given the same reference numerals, and configurations that are different from Embodiment 1 will be mainly explained. The cross section of the stator 2 shown in FIG. 10 is the cross section of the portion of the stator 2 that faces the movable element 1, as in the case of FIG.

In the second embodiment, the number of magnetic poles is three, N=4 and C=1. In the second embodiment, N/C is 4, which is an integer other than a multiple of 3. N is an integer other than a multiple of 3. By satisfying these conditions, the electric motor 52 can achieve the effect of reducing cogging torque.

In the second embodiment, each tooth 12 of the movable element 1 is assigned a tooth number for convenience. Teeth numbers t1, t2, t3, and t4 are assigned to each tooth 12 from left to right in FIG. 10, respectively.

A three-phase coil 13 is attached to the four teeth 12. A +U phase coil 13 is attached to the teeth 12 at t1. A +V phase coil 13 and a -U phase coil 13 are attached to the teeth 12 at t2. A -V phase coil 13 and a +W phase coil 13 are attached to the teeth 12 at t3. A -W phase coil 13 is attached to the teeth 12 at t4.

Each of the teeth 12 at t1 and t4 is a tooth 12 to which only a one-phase coil 13 is attached. Teeth 12 at t2 and t3 are teeth 12 to which two-phase coils 13 are attached. In this way, the plurality of teeth 12 of the mover 1 are a first tooth 12 to which only one phase coil 13 is attached, and a second tooth 12 to which a plurality of phase coils 13 are attached. Including teeth. Each tooth 12 at t1 and t4 is a first tooth. Teeth 12 at t2 and t3 are second teeth. Each of the teeth 12 at t1 and the teeth 12 at t4, which are the teeth 12 located at the ends in the moving direction of the movable element 1, is a first tooth.

In the electric motor 52, C sections 10 each made up of N/C teeth 12 are arranged in the traveling direction. In the second embodiment, one section 10 composed of four teeth 12 is arranged in the traveling direction. Further, in the second embodiment, the number of second teeth included in the section 10 is two. In the section 10, two second teeth are arranged consecutively in the traveling direction. That is, the first teeth are not arranged between the second teeth.

FIG. 11 is a diagram showing an example of the number of turns of the coil 13 attached to each tooth 12 in the second embodiment. FIG. 11 shows the number of turns of the coil 13 for each phase in each tooth 12 and the total number of turns of each tooth 12. The number of turns shown in FIG. 11 is the number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. The total number of turns shown in FIG. 11 is the total number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. That is, the number of turns of each tooth 12 and the total number of turns are expressed by the ratio to the number of turns of the entire movable element 1. Further, FIG. 11 shows the ratio of the number of series conductors for each phase to the number of series conductors in the entire movable element 1.

In the example shown in FIG. 11, the sum of 0.27, which is the total number of turns on the teeth 12 at t1, and 0.27, which is the total number of turns on the teeth 12 at t4, is 0.54. The sum of 0.23, which is the total number of turns on the teeth 12 at t2, and 0.23, which is the total number of turns on the teeth 12 at t3, is 0.46. Thus, in the second embodiment, the total number of turns of the coil 13 in all the first teeth included in the section 10 is greater than the total number of turns of the coil 13 in all the second teeth included in the section 10.

Here, the configuration of the electric motor according to a comparative example of the second embodiment will be explained. FIG. 12 is a sectional view of an electric motor 53 according to a comparative example of the second embodiment. FIG. 13 is a diagram showing an example of the number of turns of the coil 13 attached to each tooth 12 in a comparative example of the second embodiment. Similar to the electric motor 52 shown in FIG. 10, the mover 1 has four teeth 12. A +U phase coil 13 is attached to the teeth 12 at t1. A +V phase coil 13 and a -U phase coil 13 are attached to the teeth 12 at t2. A +W phase coil 13 is attached to the teeth 12 at t3. A +V phase coil 13 and a -W phase coil 13 are attached to the teeth 12 at t4.

In the electric motor 53, each of the teeth 12 at t1 and t3 is a first tooth to which only a one-phase coil 13 is attached. A two-phase coil 13 is attached to each of the teeth 12 at t2 and t4. Teeth 12 at t2 and t4 are second teeth to which a plurality of coils 13 are attached. In the electric motor 53, one first tooth is arranged between the second teeth.

In the comparative example shown in FIG. 13, the sum of 0.27, which is the total number of turns on the teeth 12 at t1, and 0.06, which is the total number of turns on the teeth 12 at t3, is 0.33. The sum of 0.34, which is the total number of turns on the teeth 12 at t2, and 0.40, which is the total number of turns on the teeth 12 at t4, is 0.74. In the comparative example, unlike the case of Embodiment 2 shown in FIG. It is less than the total number of volumes of 13.

FIG. 14 is a vector diagram showing the induced voltage in each coil 13 of the electric motor 52 according to the second embodiment. FIG. 15 is a vector diagram showing the induced voltage in each coil 13 of the electric motor 53 according to the comparative example of the second embodiment. In FIGS. 14 and 15, vectors indicated by solid arrows are induced voltage vectors. In each vector diagram of FIGS. 14 and 15, a phase angle of 360 degrees is twice the length of the pitch of the permanent magnets 21. The vector indicated by the broken line arrow is the induced voltage vector of each phase, and is a composite vector obtained by combining the induced voltage vectors of each coil 13 for each phase.

The phase difference between adjacent teeth 12 is expressed as {360×(P/2)/N} degrees using P, which is the number of magnetic poles, and N, which is the number of teeth 12. For example, in the electric motor 52, the phase difference between the teeth 12 at t1 and the teeth 12 at t2 is 360°×(3/2)/4=135°. Each tooth 12 of the electric motor 52 is arranged so that the phase difference between adjacent teeth 12 is 135 degrees. In the second embodiment as well, k _d,UVW, which is the sum of the distributed winding coefficients k _d of all phases, which are the U phase, V phase, and W phase, is determined by the same calculation as in the first embodiment.

Comparing FIG. 14 and FIG. 15, the electric motor 52 according to the second embodiment has a phase difference between "t3_V-" in FIG. 14 and the V-phase composite vector, and "t4_V+" in FIG. 15 and the V-phase composite vector. It has the characteristic of being smaller than the phase difference with the vector.

FIG. 16 is a diagram for explaining an increase in the distributed winding coefficient in the electric motor 52 according to the second embodiment. FIG. 16 shows a bar graph representing the value of the distributed winding coefficient of the electric motor 53 according to the comparative example and a bar graph representing the value of the distributed winding coefficient of the electric motor 52 according to the second embodiment. The value of the distributed winding coefficient is a value standardized based on the value of the distributed winding coefficient of the electric motor 53. That is, the value of the distributed winding coefficient is expressed by the ratio to the value of the distributed winding coefficient of the electric motor 53.

By adopting the coil arrangement shown in FIG. 10 and the number of turns shown in FIG. 11, the electric motor 52 increases the distributed winding coefficient compared to the comparative example having the coil arrangement shown in FIG. 12 and the number of turns shown in FIG. You can get the desired effect.

The electric motor 52 does not have a configuration in which the first teeth are arranged between the second teeth. Since the electric motor 52 can have a higher distributed winding coefficient than that of the comparative example, the heat generation of the coil 13 in the movable element 1 can be reduced.

The electric motor 52 can reduce the difference in induced voltage and inductance of each phase by setting the total number of turns of each tooth 12 as described above. As a result, the electric motor 52 has the effect of reducing the difference in terminal voltage of the electric motor 52. Further, since the electric motor 52 can reduce the difference in the total number of turns of each phase, it can reduce the difference in resistance values. Thereby, the electric motor 52 has the effect of reducing local heat generation of the coil 13.

In the second embodiment, the movable element 1 has a configuration that satisfies N=4 and C=1. That is, the movable element 1 has a configuration in which one section 10 composed of four teeth 12 is arranged in the traveling direction. In the electric motor 52, a plurality of sections 10 may be arranged in the traveling direction. That is, the movable element 1 may have a configuration including a plurality of sections 10. In this case, C is a natural number greater than 1. Even when C is a natural number larger than 1, the electric motor 52 can obtain the above-mentioned effect as in the case where C is 1.

In the second embodiment, the movable element 1 has a configuration in which a single section 10 or a plurality of sections 10 are arranged in the traveling direction. In addition, auxiliary teeth may be attached to each of both ends of the movable element 1 in the direction of movement. Even when auxiliary teeth are attached to both ends of the movable element 1 in the direction of movement, the electric motor 52 can obtain the same effect as when no auxiliary teeth are attached. Further, as in the case of Embodiment 1, protrusions or depressions oriented in the traveling direction may be formed at the tip portions of the teeth 12 on the field side. As in the first embodiment, the electric motor 52 may have a configuration in which a plurality of permanent magnets 21 are embedded inside the stator core.

According to the second embodiment, in the electric motor 52, C sections 10 each including N/C teeth 12 are arranged in the traveling direction, and in the section 10, two second teeth are arranged consecutively in the traveling direction. It is arranged as follows. The electric motor 52 can reduce heat generation of the coil 13 in the movable element 1 by increasing the distributed winding coefficient. As described above, the electric motor 52 has the effect of reducing heat generation of the coil 13.

Embodiment 3.
FIG. 17 is a sectional view of the electric motor 54 according to the third embodiment. In the third embodiment, the arrangement of the teeth 12 and the coil 13 in the movable element 1 is different from that in the first or second embodiment. In Embodiment 3, the same components as in

Embodiment

1 or 2 described above are given the same reference numerals, and configurations that are different from

Embodiment

1 or 2 will be mainly explained. The cross section of the stator 2 shown in FIG. 17 is the cross section of the portion of the stator 2 that faces the movable element 1, as in the case of FIG.

In the third embodiment, the number of magnetic poles is 4, with N=5 and C=1. In the third embodiment, N/C is 5, which is an integer other than a multiple of 3. N is an integer other than a multiple of 3. By satisfying these conditions, the electric motor 54 can achieve the effect of reducing cogging torque.

In the third embodiment, each tooth 12 of the mover 1 is assigned a tooth number for convenience. Teeth numbers t2, t3, t4, t5, and t1 are assigned to each tooth 12 from left to right in FIG. 17, respectively.

A three-phase coil 13 is attached to the five teeth 12. A -V phase coil 13 is attached to the teeth 12 at t2. A +V phase coil 13 and a -W phase coil 13 are attached to the teeth 12 at t3. A +W phase coil 13 is attached to the teeth 12 at t4. A +U phase coil 13 is attached to the teeth 12 at t5. A -U phase coil 13 is attached to the teeth 12 at t1.

Each of the teeth 12 at t2, t4, t5, and t1 is a tooth 12 to which only a one-phase coil 13 is attached. Teeth 12 at t3 is a tooth 12 to which a two-phase coil 13 is attached. In this way, the plurality of teeth 12 of the mover 1 are a first tooth 12 to which only one phase coil 13 is attached, and a second tooth 12 to which a plurality of phase coils 13 are attached. Including teeth. Each tooth 12 at t2, t4, t5, and t1 is a first tooth. Teeth 12 at t3 is the second tooth. Each of the teeth 12 at t2 and the teeth 12 at t1, which are the teeth 12 located at the end in the moving direction of the movable element 1, is a first tooth.

In the electric motor 54, C sections 10 each made up of N/C teeth 12 are arranged in the traveling direction. In the third embodiment, one section 10 composed of five teeth 12 is arranged in the traveling direction. Furthermore, in the third embodiment, the number of second teeth included in section 10 is one.

An insulator for insulation between phases is attached to the second teeth. The winding area of the second teeth is smaller than that of the first teeth due to the area occupied by the insulator. Furthermore, a protective component is attached to the teeth 12 located at the end of the movable element 1 in the direction of movement to protect the coil 13. The winding area of the teeth 12 located at the ends is smaller than that of the teeth 12 located at positions other than the ends due to the area occupied by the protective component.

If the second tooth is arranged at the end of the mover 1 in the direction of movement, an insulator and a protective component are attached to the second tooth, so that the winding area of the second tooth is becomes significantly smaller. In order to increase the number of turns, a coil 13 formed of a conductive wire with a small diameter is attached to the second tooth. In this case, as the wire diameter becomes smaller, the heat generated by the coil 13 increases.

In the electric motor 54, since the tooth 12 located at the end in the traveling direction of the movable element 1 is the first tooth, the winding area of the tooth 12 located at the end in the traveling direction among the plurality of teeth 12 is localized. This prevents it from becoming smaller. The coil 13 formed of a conductive wire with a large wire diameter can be placed on the first tooth located at the end in the traveling direction, so that the heat generation of the coil 13 can be reduced. As described above, the electric motor 54 has the effect that the heat generation of the coil 13 can be reduced because the tooth 12 located at the end in the moving direction of the movable element 1 is the first tooth.

Also in the first and second embodiments, the

electric motors

50 and 52 have the effect of reducing the heat generation of the coil 13 by having the tooth 12 located at the end in the moving direction of the movable element 1 as the first tooth. I can do it.

In the third embodiment, the movable element 1 has a configuration in which one section 10 composed of five teeth 12 is arranged in the traveling direction. In the electric motor 54, a plurality of sections 10 may be arranged in the traveling direction. That is, the movable element 1 may have a configuration including a plurality of sections 10. In this case, C is a natural number greater than 1. Even when C is a natural number larger than 1, the electric motor 54 can obtain the above-mentioned effect as in the case where C is 1.

In the third embodiment, the movable element 1 has a configuration in which a single section or a plurality of sections 10 are arranged in the traveling direction. In addition, auxiliary teeth may be attached to each of both ends of the movable element 1 in the direction of movement. Even when auxiliary teeth are attached to both ends of the movable element 1 in the direction of movement, the electric motor 54 can obtain the same effect as when no auxiliary teeth are attached. Further, as in the case of

Embodiment

1 or 2, a protrusion or a depression oriented in the traveling direction may be formed at the tip of the tooth 12 on the field side. As in the case of

Embodiment

1 or 2, the electric motor 54 may have a configuration in which a plurality of permanent magnets 21 are embedded inside the stator core.

Embodiment 4.
FIG. 18 is a sectional view of the electric motor 55 according to the fourth embodiment. In the fourth embodiment, the arrangement of the teeth 12 and the coil 13 in the movable element 1 is different from that in the first to third embodiments. In Embodiment 4, the same components as in Embodiments 1 to 3 described above are given the same reference numerals, and configurations that are different from Embodiments 1 to 3 will be mainly explained. The cross section of the stator 2 shown in FIG. 18 is the cross section of the portion of the stator 2 that faces the movable element 1, as in the case of FIG.

In the fourth embodiment, the number of magnetic poles is three, N=4 and C=1. In the fourth embodiment, N/C is 4, which is an integer other than a multiple of 3. N is an integer other than a multiple of 3. By satisfying these conditions, the electric motor 54 can achieve the effect of reducing cogging torque.

In the fourth embodiment, each tooth 12 of the mover 1 is assigned a tooth number for convenience. Teeth numbers t1, t2, t3, and t4 are assigned to each tooth 12 from left to right in FIG. 18, respectively.

A three-phase coil 13 is attached to the four teeth 12. A +U phase coil 13 is attached to the teeth 12 at t1. A +V phase coil 13 is attached to the teeth 12 at t2. A +W phase coil 13 and a −V phase coil 13 are attached to the teeth 12 at t3. A -W phase coil 13 is attached to the teeth 12 at t4.

Each of the teeth 12 at t1, t2, and t4 is a tooth 12 to which only a one-phase coil 13 is attached. Teeth 12 at t3 is a tooth 12 to which a two-phase coil 13 is attached. In this way, the plurality of teeth 12 of the mover 1 are a first tooth 12 to which only one phase coil 13 is attached, and a second tooth 12 to which a plurality of phase coils 13 are attached. Including teeth. Each tooth 12 at t1, t2, and t4 is a first tooth. Teeth 12 at t3 is the second tooth. Each of the teeth 12 at t1 and the teeth 12 at t4, which are the teeth 12 located at the ends in the moving direction of the movable element 1, is a first tooth. The electric motor 55 can reduce heat generation of the coil 13 because the tooth 12 located at the end in the moving direction of the movable element 1 is the first tooth.

In the electric motor 55, C sections 10 each made up of N/C teeth 12 are arranged in the traveling direction. In the fourth embodiment, one section 10 composed of four teeth 12 is arranged in the traveling direction. Furthermore, in the fourth embodiment, the number of second teeth in section 10 is one.

FIG. 19 is a diagram showing an example of the number of turns of the coil 13 attached to each tooth 12 in the fourth embodiment. FIG. 19 shows the number of turns of the coil 13 for each phase in each tooth 12 and the total number of turns of each tooth 12. The number of turns shown in FIG. 19 is the number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. The total number of turns shown in FIG. 19 is the total number of turns standardized based on the number of turns of the plurality of teeth 12 as a whole. That is, the number of turns of each tooth 12 and the total number of turns are expressed by the ratio to the number of turns of the entire movable element 1. Further, FIG. 19 shows the ratio of the number of series conductors for each phase to the number of series conductors in the entire movable element 1.

As shown in FIG. 19, the total number of turns in the teeth 12 at t3 is 0.23. Each of the teeth 12 at t2 and the teeth 12 at t4 is a first tooth adjacent to a second tooth. Teeth 12 at t1 is a first tooth adjacent to a second tooth via one first tooth. The total number of turns in the teeth 12 at t1, 0.32, is greater than the total number of turns, 0.23, in each of the teeth 12 at t2 and the teeth 12 at t4. In this way, in section 10 of the fourth embodiment, the total number of turns of the coil 13 in the first tooth adjacent to the second tooth via one first tooth is The number of turns is greater than the total number of turns of the coil 13 in one tooth.

FIG. 20 is a diagram for explaining an increase in the distributed winding coefficient in the electric motor 55 according to the fourth embodiment. Here, it is assumed that the configuration of the comparative example according to the fourth embodiment is the configuration of the electric motor 53 shown in FIG. 12. FIG. 20 shows a bar graph representing the value of the distributed winding coefficient of the electric motor 53 according to the comparative example and a bar graph representing the value of the distributed winding coefficient of the electric motor 55 according to the fourth embodiment. The value of the distributed winding coefficient is a value standardized based on the value of the distributed winding coefficient of the electric motor 53. That is, the value of the distributed winding coefficient is expressed by the ratio to the value of the distributed winding coefficient of the electric motor 53.

By adopting the coil arrangement shown in FIG. 18 and the number of turns shown in FIG. 19, the electric motor 55 increases the distributed winding coefficient compared to the comparative example having the coil arrangement shown in FIG. 12 and the number of turns shown in FIG. You can get the desired effect.

The electric motor 55 does not have a configuration in which the first teeth are arranged between the second teeth. Since the electric motor 55 can have a higher distributed winding coefficient than that of the comparative example, the heat generation of the coil 13 in the movable element 1 can be reduced.

By setting the total number of turns of each tooth 12 as described above, the electric motor 55 can reduce the difference in induced voltage in each phase, and can also reduce the difference in inductance in each phase. Furthermore, the electric motor 55 can increase the distributed winding coefficient. The electric motor 55 can reduce the heat generation of the coil 13 by being able to reduce the current value when obtaining the same thrust force. As described above, the electric motor 55 has the effect of reducing heat generation of the coil 13.

In the fourth embodiment, the movable element 1 has a configuration in which one section 10 composed of four teeth 12 is arranged in the traveling direction. In the electric motor 55, a plurality of sections 10 may be arranged in the traveling direction. That is, the movable element 1 may have a configuration including a plurality of sections 10. In this case, C is a natural number greater than 1. Even when C is a natural number larger than 1, the electric motor 55 can obtain the above-mentioned effect as in the case where C is 1.

In the fourth embodiment, the movable element 1 has a configuration in which a single section or a plurality of sections 10 are arranged in the traveling direction. In addition, auxiliary teeth may be attached to each of both ends of the movable element 1 in the direction of movement. Even when auxiliary teeth are attached to both ends of the movable element 1 in the moving direction, the electric motor 55 can obtain the same effect as when no auxiliary teeth are attached. Further, as in the first to third embodiments, a protrusion or a depression facing in the direction of movement may be formed at the tip of the tooth 12 on the field side. As in the first to third embodiments, the electric motor 55 may have a configuration in which a plurality of permanent magnets 21 are embedded inside the stator core.

Embodiment 5.
FIG. 21 is a sectional view of the electric motor 56 according to the fifth embodiment. In the fifth embodiment, the arrangement of each coil 13 in the tooth 12 of t3, which is the second tooth, is different from that of the electric motor 50 shown in FIG. The configuration of the electric motor 56 is similar to that of the electric motor 50, except that the arrangement of each coil 13 in the teeth 12 at t3 is different from that of the electric motor 50. In Embodiment 5, the same components as those in Embodiments 1 to 4 described above are given the same reference numerals, and configurations that are different from Embodiments 1 to 4 will be mainly described. The cross section of the stator 2 shown in FIG. 21 is the cross section of the portion of the stator 2 that faces the movable element 1, as in the case of FIG.

Each tooth 12 extends from the core back 11 toward the stator 2. The direction from the core back 11 toward the stator 2 is defined as the longitudinal direction of the teeth 12. In the teeth 12 at t3 shown in FIG. 2, the +V phase coil 13 and the -W phase coil 13 are adjacent to each other in the longitudinal direction of the teeth 12. On the other hand, in the tooth 12 at t3 shown in FIG. 21, the +V phase coil 13 is wound inside, which is the tooth 12 side. The -W phase coil 13 is wound outside the +V phase coil 13. That is, in the teeth 12 at t3, a +V phase coil 13 is attached and a -W phase coil 13 is attached. Note that, in addition to the −W phase coil 13 attached to the teeth 12 at t3, the +V phase coil 13 may also be attached.

By arranging each coil 13 of the second teeth as described in Embodiment 5, the winding start position of the coil 13 and the winding end position of the coil 13 can be set at the position in contact with the core back 11. You can arrange them. That is, for all the coils 13 provided in the mover 1, the winding start position of the coil 13 and the winding end position of the coil 13 can be aligned on the core back 11 side. In this case, the distance from the winding end position of the coil 13 to the neutral point or the distance from the winding start position of the coil 13 to the terminal can be minimized, and the resistance of the coil 13 can be lowered. . Thereby, the electric motor 56 has the effect of reducing heat generation of the coil 13.

By arranging each coil 13 of the second teeth as described in Embodiment 5, the magnetic flux passing through the coil 13 can be kept the same. Therefore, the electric motor 56 can reduce the difference in inductance of each phase, and the effect of reducing the difference in terminal voltage of the electric motor 56 can be obtained.

In the fifth embodiment, the movable element 1 has a configuration in which one section 10 composed of five teeth 12 is arranged in the traveling direction. In the electric motor 56, a plurality of sections 10 may be arranged in the traveling direction. That is, the movable element 1 may have a configuration including a plurality of sections 10. In this case, C is a natural number greater than 1. Even when C is a natural number larger than 1, the electric motor 56 can obtain the above-mentioned effect as in the case where C is 1.

In the fifth embodiment, the movable element 1 has a configuration in which a single section or a plurality of sections 10 are arranged in the traveling direction. In addition, auxiliary teeth may be attached to each of both ends of the movable element 1 in the direction of movement. Even when auxiliary teeth are attached to both ends of the movable element 1 in the moving direction, the electric motor 56 can obtain the same effect as when no auxiliary teeth are attached. Further, as in the first to fourth embodiments, a protrusion or a depression facing in the direction of movement may be formed at the tip of the tooth 12 on the field side. As in the first to fourth embodiments, the electric motor 56 may have a configuration in which a plurality of permanent magnets 21 are embedded inside the stator core.

The configurations of

electric motors

50, 52, 54, 55, and 56 according to Embodiments 1 to 5 may be applied to rotating electrical machines. A rotating electric machine is an electric motor that includes a stator and a rotor and rotates the rotor. Even when the configuration of the

electric motors

50, 52, 54, 55, 56 is applied to a rotating electric machine, the same effects as in the case of the

electric motors

50, 52, 54, 55, 56 can be obtained.

The configurations shown in each of the embodiments above are examples of the content of the present disclosure. The configuration of each embodiment can be combined with other known techniques. The configurations of each embodiment may be combined as appropriate. It is possible to omit or change a part of the configuration of each embodiment without departing from the gist of the present disclosure.

1 Mover, 2 Stator, 10 Section, 11 Core back, 12 Teeth, 13 Coil, 21 Permanent magnet, 22 Mounting seat, 50, 51, 52, 53, 54, 55, 56 Electric motor, 60 Guide, 70 Slider, 100 Electric motor system.

Claims

Field magnet and
an armature disposed facing the field and movable relative to the field;
The armature includes a core back, a plurality of teeth each extending from the core back toward the field, and arranged in a direction in which the armature moves with respect to the field, and a plurality of teeth. a plurality of coils attached to the
The plurality of teeth include a first tooth that is a tooth to which only the coil of one phase is attached, and a second tooth that is a tooth to which the coils of a plurality of phases are attached,
Each of the plurality of coils is arranged so as not to straddle a slot formed by adjacent teeth,
The number of teeth of the armature is N, and the greatest common divisor of N, which is the number of teeth, and the number of magnetic poles of the field in the range facing the N teeth, is N/C. C sections composed of C teeth are arranged in the traveling direction,
An electric motor characterized in that, in the section, two of the second teeth are arranged consecutively in the traveling direction, or the number of the second teeth included in the section is one.
The electric motor according to claim 1, wherein the teeth located at the ends of the armature in the direction of movement are the first teeth.
N/C is 4 and the second teeth included in the section is one,
The total number of turns of the coil in the first tooth adjacent to the second tooth via one of the first teeth is the total number of turns of the coil in the first tooth adjacent to the second tooth. The electric motor according to claim 1 or 2, characterized in that the number of turns is greater than the number of turns.
N/C is 4 and the second teeth included in the section are two,
2. The total number of turns of the coil in all the first teeth included in the section is greater than the total number of turns of the coil in all the second teeth included in the section. 2. The electric motor according to 2.
N/C is 5 and the number of the second teeth included in the section is one,
The total number of turns of the coil in the first tooth adjacent to the second tooth is greater than the total number of turns of the coil in the second tooth, and the Claim 1, wherein the total number of turns of the coil in the first tooth adjacent to the second tooth is smaller than the total number of turns of the coil in the first tooth adjacent to the second tooth. or the electric motor described in 2.