electric motor

Abstract

Comprise: first tooth (13G); with first tooth (13G) circumferentially adjacent, and form with the coil (14) formed in the first tooth (13G) same phase coil (14) of the second tooth (13H); And with first tooth (13G) circumferentially adjacent, and form with the coil (14) formed in the first tooth (13G) opposite phase coil (14) of the third tooth (13F). From the first tooth (13G) of the first flange part (132GF) in the circumferential direction of the top end to the extension (131) of the first tooth (13G) of the circumferential center of the magnetic resistance size is smaller than from the first tooth (13G) of the second flange part (132GR) in the circumferential direction of the top end to the extension (131) of the first tooth (13G) of the circumferential center of the magnetic resistance size, the first flange part (132GF) extends to the second tooth (13H) side, the second flange part (132GR) extends to the third tooth (13F) side.

Description

Technical Field

[0001] This disclosure relates to an electric motor. Background Technology

[0002] In the prior art, there is a known stator in which a state in which coils of the same phase are formed on adjacent teeth in the circumferential direction and a state in which coils of different phases are formed on adjacent teeth in the circumferential direction alternately in the circumferential direction. Such a stator is described, for example, in Patent Document 1.

[0003] The stator described in Patent Document 1 includes multiple teeth and a yoke. The teeth are of the same size and are arranged at equal intervals along the circumferential direction, extending towards the rotor. The yoke is annular and engages with the teeth. In the embodiment described in Patent Document 1, 12 teeth are provided, each wound with a winding. These windings are suitably connected to a three-phase power supply to supply U-phase, V-phase, or W-phase power to the windings, which are divided into three groups of four windings each. Therefore, in the stator disclosed in Patent Document 1, the state in which coils of the same phase are formed on adjacent circumferentially adjacent teeth and the state in which coils of different phases are formed on adjacent circumferentially adjacent teeth alternate along the circumferential direction.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2008-86064 Summary of the Invention

[0007] -The technical problem the invention aims to solve-

[0008] However, in the stator described in Patent Document 1, there is a possibility of magnetic flux leakage and short circuit between adjacent teeth where in-phase coils are formed, resulting in a magnetic flux path that circulates only within the stator. Therefore, when combined with the rotor, there is an increase in induced voltage, so a countermeasure is needed to further expand the operating range.

[0009] The purpose of this disclosure is to expand the operating range by making it difficult to generate magnetic flux between adjacent teeth of coils that are in phase.

[0010] - Technical solutions used to solve technical problems -

[0011] The first aspect of this disclosure pertains to an electric motor 1, which includes: a rotor 20 that rotates freely about a rotation axis 30; and a stator 10 arranged radially opposite to the rotor 20. The stator 10 includes a stator core 11 comprising: a roughly annular magnetic yoke 12; and a plurality of teeth 13 extending radially from the magnetic yoke 12 toward the rotor 20 and spaced apart circumferentially along the magnetic yoke 12. Each of the plurality of teeth 13 has: an extension 131 on which a winding is wound in a concentrated winding manner to form a coil 14; and a flange 132 extending radially from a top radial portion of the extension 131 toward both circumferential sides. The plurality of teeth 13 include: a first tooth 13G; a second tooth 13H, which is circumferentially adjacent to the first tooth 13G and has a coil 14 in phase with the coil 14 formed on the first tooth 13G; and a third tooth 13F, which is circumferentially adjacent to the first tooth 13G and has a coil 14 out of phase with the coil 14 formed on the first tooth 13G. The flange portion 132 has: a first flange portion 132GF of the first tooth 13G, extending toward the second tooth 13H; and a second flange portion 132GR of the first tooth 13G, extending toward the third tooth 13F. The magnitude of the magnetic reluctance from the circumferentially apex of the first flange portion 132GF to the circumferentially center of the extension portion 131 of the first tooth 13G is a first magnetic reluctance. The magnitude of the magnetic resistance from the top circumferential portion of the second flange portion 132GR to the circumferential center of the extension portion 131 of the first tooth 13G is the second magnetic resistance, and the magnitude of the second magnetic resistance is smaller than the magnitude of the first magnetic resistance.

[0012] In the electric motor 1 of the first aspect, short circuits of magnetic flux are difficult to occur between adjacent teeth 13G and 13H where in-phase coils 14 are formed, thus suppressing the generation of magnetic flux paths that circulate only within the stator core 11. Therefore, the increase in induced voltage can be suppressed, thereby expanding the operating range.

[0013] The second aspect of this disclosure is that, based on the motor 1 of the first aspect described above, a gap is formed in the first flange portion 132GF, while no gap is formed in the second flange portion 132GR.

[0014] In the second aspect, without significantly altering the shapes of the first flange portion 132GF and the second flange portion 132GR, a simple structure is achieved where the magnetic reluctance of the portion of the tooth 13G near the first flange portion 132GF in the width direction is greater than that of the portion of the tooth 13G near the second flange portion 132GR in the width direction. Therefore, the number of turns of the coil 14 remains unchanged, and the area of ​​the flange portion 132 opposite to the permanent magnet 21 of the rotor also remains unchanged, thus preserving the linkage flux of the permanent magnet 21 of the rotor 20.

[0015] The third aspect of this disclosure is that, based on the motor 1 of the second aspect described above, the gap formed in the first flange portion 132GF is a plurality of holes 133.

[0016] In the third aspect, by appropriately designing the layout of the multiple holes 133, the strength of the flange portion 132 of the tooth 13 can be ensured. Therefore, the effect of the flange portion 132 in holding the coil 14 is not sacrificed.

[0017] The fourth aspect of this disclosure is that, based on the electric motor 1 of the first aspect described above, the first flange portion 132GF comprises a material with a lower magnetic permeability than the material constituting the second flange portion 132GR.

[0018] In the fourth aspect, without significantly altering the shape of the first flange portion 132GF and the second flange portion 132GR, a simple structure is achieved where the magnetic reluctance of the portion of the tooth 13 near the first flange portion 132GF in the width direction is greater than that of the portion of the tooth 13 near the second flange portion 132GR in the width direction. Therefore, the number of turns of the coil 14 remains unchanged, ensuring the strength of the flange portion 132 of the tooth 13. Furthermore, the area of ​​the flange portion 132 relative to the permanent magnet 21 of the rotor 20 remains unchanged, without sacrificing the linkage flux of the permanent magnet 21 of the rotor.

[0019] The fifth aspect of this disclosure is that, based on the electric motor 1 described in any of the first to fourth aspects, the stator core 11 is formed by stacking multiple laminated plates P. A riveting portion 233 for fastening the multiple laminated plates P is provided at the first flange portion 132GF.

[0020] In the fifth aspect, it is known that compressive stress is generated in the portion where the riveting part is provided, and the magnetic reluctance increases due to the deterioration of the magnetic properties. In this structure, by providing the riveting part in the first flange portion 132GF, it is possible to suppress the generation of magnetic flux short circuits between adjacent teeth 13 where in-phase coils 14 are formed.

[0021] The sixth aspect of this disclosure is that, based on the motor 1 of the first aspect described above, the stator core 11 is formed by stacking multiple laminated plates P. The multiple laminated plates P include: a first laminate P1, wherein the magnetic reluctance of the first flange portion 132GF of the first laminate P1 is smaller than the magnetic reluctance of the second flange portion 132GR of the first laminate P1; and a second laminate P2, wherein the magnetic reluctance of the first flange portion 132GF of the second laminate P2 is no different from the magnetic reluctance of the second flange portion 132GR of the second laminate P2. The first laminate P1 and the second laminate P2 are stacked alternately at predetermined intervals.

[0022] In the sixth aspect, the stator core 11 can be endowed with desired characteristics related to the magnitude of magnetic reluctance and rigidity.

[0023] The seventh aspect of this disclosure is that, based on the motor 1 of the first aspect described above, the stator core 11 is formed by stacking multiple laminated plates P. The multiple laminated plates P include: a first laminate P1, wherein the magnetic reluctance of the first flange portion 132GF of the first laminate P1 is smaller than the magnetic reluctance of the second flange portion 132GR of the first laminate P1; and a second laminate P2, wherein the magnetic reluctance of the first flange portion 132GF of the second laminate P2 is no different from the magnetic reluctance of the second flange portion 132GR of the second laminate P2. The first laminate P1 and the second laminate P2 are stacked in a desired order.

[0024] In the seventh aspect, the stator core 11 can be given the desired characteristics related to the magnitude of magnetic reluctance and stiffness with a higher degree of freedom.

[0025] The eighth aspect of this disclosure is that, based on the electric motor 1 of the first aspect described above, a plurality of teeth 13 are arranged at intervals along the circumference of the magnetic yoke 12. When viewed axially, all of the plurality of teeth 13 have the same shape. When viewed axially, each tooth 13 has a shape that is linearly symmetrical with respect to the centerline of the tooth width direction.

[0026] In existing technologies, to reduce leakage flux, the following measures are sometimes taken: on the side adjacent to the coil in phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively short; on the side adjacent to the coil out of phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively long. With such a structure, the space for inserting the nozzle for winding is limited by a narrower slot, while the effect of the flange in holding the winding is limited by a wider slot, resulting in significant constraints during production and decreased productivity. In contrast, in the eighth aspect, all teeth 13 have flanges and extensions of the same width, and the slots between the teeth 13 are all of the same shape and size. Therefore, the winding can be wound in the same manner for all teeth 13, improving productivity. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of the electric motor according to the first embodiment of this disclosure, cut perpendicular to the axial direction. Figure 2 yes Figure 1 A magnified view of a portion of the image; Figure 3 It is a three-dimensional view showing, in part, adjacent teeth forming coils of the same phase; Figure 4 This is a partial enlarged view of a plurality of adjacent teeth in a modified example of the first embodiment; Figure 5 This is a partial perspective view showing adjacent teeth of coils with the same phase formed in the second embodiment; Figure 6 This is an exploded perspective view of adjacent teeth forming coils of the same phase in the third embodiment. Figure 7 This is an exploded perspective view of adjacent teeth forming coils of the same phase in the fourth embodiment. Detailed Implementation

[0028] The embodiments of this disclosure will now be described with reference to the accompanying drawings. It should be noted that the following embodiments are merely preferred examples and are not intended to limit the scope of the invention, its application, or its uses.

[0029] (Implementation Method)

[0030] <1. First Implementation>

[0031] <1-1. Overall Structure of the Electric Motor>

[0032] Below, refer to Figure 1 The structure of the electric motor 1 according to this embodiment will be described. Figure 1This is a cross-sectional view taken perpendicular to the axial direction after cutting through the electric motor 1 according to this embodiment. The electric motor 1 is, for example, installed in the compressor of an air conditioner. Figure 1 As shown, the motor 1 includes a stator 10, a rotor 20, and a rotating shaft 30.

[0033] It should be noted that in the following description, the direction extending along the axis of rotation 30 is sometimes referred to as the axial direction, the direction extending along the circle centered on the axis of rotation 30 is referred to as the circumferential direction, and the direction extending perpendicular to the axis of rotation 30 is referred to as the radial direction.

[0034] The rotating shaft 30 is cylindrical and extends axially. The rotating shaft 30 is connected to the object to which power is supplied. The rotor 20 is configured to rotate freely about the rotating shaft 30. The stator 10 and the rotor 20 are arranged radially opposite each other.

[0035] In this embodiment, the stator 10 is arranged on the outer periphery of the motor 1 and fixed to a housing (not shown). The stator 10 includes a stator core 11 and windings (not shown).

[0036] The stator core 11 is formed by stacking multiple electromagnetic steel plates P as laminates along the axial direction. The stator core 11 of this embodiment includes a magnetic yoke 12, which, when viewed axially, is approximately annular, or more specifically, approximately circular. The stator core 11 also includes a plurality of teeth 13 extending radially from the inner circumferential surface of the magnetic yoke 12 toward the radially inward side (the rotor 20 side described later). The plurality of teeth 13 are arranged at equal intervals along the circumference of the magnetic yoke 12.

[0037] Each tooth 13 has an extension 131 and a flange 132. The extension 131 extends radially inward from the inner circumference of the yoke 12. A coil 14 is formed by winding a coil in a concentrated manner on each tooth 13. The flange 132 extends circumferentially from the top end of the radially inward side of the extension 131. The flange 132 presses against the coil 14 wound on the extension 131.

[0038] like Figure 1 As shown, in this embodiment, a total of 12 teeth 13 are provided. Corresponding windings are wound on these teeth 13, and by flowing a specified current through these windings, the stator 10 is made to have 10 poles along its circumference.

[0039] Specifically, the windings are connected to a three-phase power supply (not shown) to supply power to the U-phase, V-phase, or W-phase windings, which are divided into three groups of four windings each. This three-phase power supply controls the rotation of the motor 1, for example, by outputting pulse-width modulation (PWM) signals, which are voltage signals corresponding to the aforementioned pulse widths.

[0040] More specifically, such as Figure 1 As shown, the arrangement becomes the following pattern: two coils supplied with U-phase power are continuous circumferentially, two coils supplied with W-phase power are continuous circumferentially on one side of the circumferential side, two coils supplied with V-phase power are continuous circumferentially on one side of the circumferential side, two coils supplied with U-phase power are continuous circumferentially on one side of the circumferential side, two coils supplied with W-phase power are continuous circumferentially on one side of the circumferential side, two coils supplied with V-phase power are continuous circumferentially on one side of the circumferential side, and the circumferential side is adjacent to the original coil supplied with U-phase power.

[0041] Ten permanent magnets 21 are embedded at equal intervals along the circumference of the rotor 20. This gives the rotor 20 a 10-pole configuration along the circumference. Various known permanent magnets can be used as the permanent magnets 21, such as neodymium magnets. The permanent magnets 21 are arranged with alternating N and S poles along the circumference.

[0042] In this embodiment, the motor 1 is a 10-pole, 12-slot motor. Compared with a general motor with a pole-to-slot ratio of 2:3, the winding coefficient can be increased, thereby enabling effective utilization of the linkage flux of the permanent magnet 21 of the motor 1.

[0043] It should be noted that the correspondence between the 12 teeth 13A~13L and the phase of coil 14 is as follows: Figure 1 As shown, the following explanation is provided.

[0044] <1-2. Detailed Structure of Teeth>

[0045] When viewed along the axial direction, all 12 teeth 13A to 13L have the same shape. When viewed along the axial direction, teeth 13A to 13L each have a shape that is linearly symmetrical with respect to the center line of the tooth width direction.

[0046] When focusing on tooth 13G, tooth 13H is circumferentially adjacent to tooth 13G. A coil U- is formed on tooth 13H, and the coil U- is in phase with the coil U+ formed on tooth 13G. That is, when tooth 13G is regarded as the "first tooth" according to this embodiment, tooth 13H can be regarded as the "second tooth".

[0047] Similarly, the relationships between teeth 13I and 13J, teeth 13K and 13L, teeth 13A and 13B, teeth 13C and 13D, and teeth 13E and 13F can also be regarded as the relationship between the "first tooth" and the "second tooth".

[0048] When focusing on tooth 13G, tooth 13F is circumferentially adjacent to tooth 13G. A coil V+ is formed on tooth 13F, which is out of phase with the coil U+ formed on tooth 13G. That is, when tooth 13G is regarded as the "first tooth" in this embodiment, tooth 13F can be regarded as the "third tooth".

[0049] Similarly, the relationships between teeth 13H and 13I, teeth 13J and 13K, teeth 13L and 13A, teeth 13B and 13C, and teeth 13D and 13E can also be regarded as the relationship between the "first tooth" and the "third tooth".

[0050] like Figure 2 As shown, the flange portion 132GF on the circumferential side of the flange portion 132 of the tooth 13G extends towards the side adjacent to the coil U-, which is in phase with the coil U+ formed on the tooth 13G. Therefore, this flange portion 132GF can be regarded as the "first flange portion" according to this embodiment. In this embodiment, a gap is formed in the flange portion 132GF, which is the first flange portion. Specifically, as Figure 3 As shown, an axially extending through hole (hole) 133 is formed in the flange portion 132GF.

[0051] Similarly, the flange portion 132HR on the other side of the circumference of tooth 13H, the flange portion 132 on one side of the circumference of tooth 13I, the flange portion 132 on the other side of the circumference of tooth 13J, the flange portion 132 on one side of the circumference of tooth 13K, the flange portion 132 on the other side of the circumference of tooth 13L, the flange portion 132 on one side of the circumference of tooth 13A, the flange portion 132 on the other side of the circumference of tooth 13B, the flange portion 132 on one side of the circumference of tooth 13C, the flange portion 132 on the other side of the circumference of tooth 13D, the flange portion 132 on one side of the circumference of tooth 13E, and the flange portion 132FR on the other side of the circumference of tooth 13F can also be regarded as the "first flange portion" involved in this embodiment. A through hole (hole) 133 extending axially is formed in each of these flange portions 132.

[0052] The flange portion 132GR on the other side of the flange portion 132 of tooth 13G extends towards the side adjacent to coil V+, which is out of phase with coil U+ formed on tooth 13G. Therefore, this flange portion 132GR can be regarded as the "second flange portion" according to this embodiment. In this embodiment, no gap is formed in the flange portion 132GR, which is the second flange portion.

[0053] Similarly, the flange portion 132HF on one circumferential side of tooth 13H, the flange portion 132 on the other circumferential side of tooth 13I, the flange portion 132 on one circumferential side of tooth 13J, the flange portion 132 on the other circumferential side of tooth 13K, the flange portion 132 on one circumferential side of tooth 13L, the flange portion 132 on the other circumferential side of tooth 13A, the flange portion 132 on one circumferential side of tooth 13B, the flange portion 132 on the other circumferential side of tooth 13C, the flange portion 132 on one circumferential side of tooth 13D, the flange portion 132 on the other circumferential side of tooth 13E, and the flange portion 132FF on one circumferential side of tooth 13F can also be considered as the "second flange portion" according to this embodiment. No gaps are formed in these flange portions 132.

[0054] Based on the above structure, in the motor 1 of this embodiment, the magnetic reluctance increases between adjacent teeth 13 where in-phase coils 14 are formed. Specifically, for example, gaps are formed between adjacent teeth 13G and 13H where in-phase coils 14 are formed, at the adjacent flange portions 132GF and 132HR. The gaps are filled with fluid (e.g., air or refrigerant), the permeability of which is lower than the permeability of the material constituting the stator core 11. As a result, it is difficult for short circuits of magnetic flux to occur between adjacent teeth 13 where in-phase coils 14 are formed, thereby suppressing the generation of magnetic flux paths that circulate only within the stator core 11. Therefore, the increase in induced voltage can be suppressed, thereby expanding the operating range.

[0055] <2. First variation of the first embodiment>

[0056] Below, refer to Figure 4 The structure of the electric motor 1 according to the first variation of the first embodiment will be described. Figure 4 This is a partially enlarged view of a plurality of adjacent teeth 13 in a first variation of the first embodiment.

[0057] The difference between this modified example and the first embodiment is that the first flange portion of the tooth 13 in this modified example has a riveting portion 233 instead of a through hole 133. On the flange portion 132GF on the circumferential side of the tooth 13G, which is one example of the first flange portion, a riveting portion 233 is provided to fasten the plurality of electromagnetic steel plates P constituting the stator core 11. Similarly, on the flange portion 132HR on the other circumferential side of the tooth 13H, which is another example of the first flange portion, a riveting portion 233 is also provided to fasten the plurality of electromagnetic steel plates P constituting the stator core 11.

[0058] On the other hand, no riveting part is provided on the flange portion 132GR on the other side of the circumferential direction of the tooth 13G, which is one example of the second flange portion. Similarly, no riveting part is provided on the flange portion 132HF on the circumferential direction of the tooth 13H, which is another example of the second flange portion.

[0059] Riveting portions are also provided on the other first flange portions with 12 teeth 13A to 13L. No riveting portion is provided on any of the other second flange portions with 12 teeth 13A to 13L.

[0060] Generally, compressive stress occurs in the portion where a riveting part is provided to fasten the multiple laminated plates (electromagnetic steel plates) constituting the iron core, and the resistance increases due to the deterioration of magnetic properties. In this modified example, by providing a riveting part 233 on the first flange portion of the tooth 13, it is possible to suppress the generation of magnetic flux short circuits between adjacent teeth 13 where in-phase coils 14 are formed. Therefore, the increase in induced voltage can be suppressed, thereby expanding the operating range.

[0061] <3. Second variation of the first embodiment>

[0062] The structure of the electric motor 1 according to the second variation of the first embodiment will now be described.

[0063] The difference between this modified example and the first embodiment is that the through hole 133 of the first flange portion of the tooth 13 in this modified example is filled with a material whose magnetic permeability is lower than that of the material constituting the stator core 11. That is, the first flange portion of this embodiment contains a material whose magnetic permeability is lower than that of the material constituting the second flange portion.

[0064] Based on the structure described above, in the electric motor 1 of this modified example, without changing the shape of the first flange portion and the second flange portion of the tooth 13, the magnetic reluctance of the portion of the tooth 13 near the first flange portion in the width direction is made larger than the magnetic reluctance of the portion of the tooth 13 near the second flange portion in the width direction with a simple structure.

[0065] It should be noted that in the prior art, the following measures are considered to reduce leakage flux: on the side adjacent to the coil in phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively short; on the side adjacent to the coil out of phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively long. However, with such a structure, the number of turns of the coil changes, the strength of the teeth differs at both ends of the teeth in the circumferential direction, and consequently, the area of ​​the flange relative to the permanent magnet of the rotor also changes.

[0066] Regarding this, according to the electric motor 1 of this modified example, it is possible to suppress short circuits that generate magnetic flux between adjacent teeth 13 and coils 14 with the same phase, without changing the number of turns of the coil 14, and to ensure the strength of the flange portion 132 of the tooth 13. Moreover, the area of ​​the flange portion 132 opposite to the permanent magnet 21 of the rotor 20 will not change, and the linkage magnetic flux of the permanent magnet 21 of the rotor 20 will not be sacrificed.

[0067] <4. Second Implementation>

[0068] Below, refer to Figure 5 The structure of the electric motor 1 according to the second embodiment will be described. Figure 5 This is a perspective view showing, in part, adjacent teeth 13 of which are formed with in-phase coils in the second embodiment.

[0069] The second embodiment differs from the first embodiment in that each first flange portion of the tooth 13 in the second embodiment has two through holes, namely a first through hole 333 and a second through hole 334, instead of one through hole 133. Both the first through hole 333 and the second through hole 334 are triangular holes when viewed axially. When viewed axially, the first through hole 333 and the second through hole 334 are arranged adjacent to each other with ribs between them.

[0070] In the second embodiment, as described above, by arranging the first through-hole 333 and the second through-hole 334 adjacent to each other with ribs in between, i.e., forming a so-called truss structure, the strength of the flange portion 132 of the tooth 13 can be ensured. Therefore, the effect of the flange portion 132 in holding the coil 14 is not sacrificed. According to the structure of the second embodiment, it is also difficult to generate a magnetic flux short circuit between adjacent teeth 13 where the coils 14 of the same phase are formed.

[0071] <5. Third Implementation>

[0072] Below, refer to Figure 6 The structure of the electric motor 1 according to the third embodiment will be described. Figure 6 This is an exploded perspective view of adjacent teeth 13 of coils 14 with the same phase formed in the third embodiment.

[0073] The difference between the third embodiment and the first embodiment is that, in the third embodiment, the stator core 11 is formed by alternately stacking various types of electromagnetic steel plates P at predetermined intervals. For example... Figure 6 As shown, the stator core 11 of the third embodiment is composed of a first electromagnetic steel plate P1 and a second electromagnetic steel plate P2.

[0074] The first electromagnet plate P1 includes a yoke 12 and teeth 13. A through hole 433 is formed in the first flange portion of the first electromagnet plate P1, but no through hole is formed in the second flange portion. The second electromagnet plate P2 includes a yoke 12 and teeth 13. No through hole is formed in the first flange portion of the second electromagnet plate P2, nor in the second flange portion.

[0075] The first electromagnetic steel plate P1 and the second electromagnetic steel plate P2 are stacked alternately at predetermined intervals. In this embodiment, the first electromagnetic steel plate P1 and the second electromagnetic steel plate P2 are stacked alternately one sheet at a time. However, this is not a limitation; for example, the first electromagnetic steel plate and the second electromagnetic steel plate may be stacked alternately every two sheets.

[0076] By using a stator core 11 with the above structure, the stator 10 can be endowed with desired characteristics related to the magnitude of magnetic reluctance and rigidity.

[0077] <6. Fourth Implementation>

[0078] Below, refer to Figure 7 The structure of the electric motor 1 according to the fourth embodiment will be described. Figure 7 This is an exploded perspective view of adjacent teeth 13 of coils 14 with the same phase formed in the fourth embodiment.

[0079] The fourth embodiment differs from the third embodiment in that, in the fourth embodiment, the stator core 11 is formed by stacking the first electromagnetic steel plate P1 and the second electromagnetic steel plate P2 in a desired order. For example... Figure 7 As shown, similar to the third embodiment, the stator core 11 of the fourth embodiment is composed of a first electromagnetic steel plate P1 and a second electromagnetic steel plate P2.

[0080] The first electromagnetic steel plate P1 and the second electromagnetic steel plate P2 are stacked axially in an irregular order. In other words, the first electromagnetic steel plate P1 and the second electromagnetic steel plate P2 are stacked axially in an order desired by the manufacturer.

[0081] By using the stator core 11 with the above structure, the stator 10 can be given the desired characteristics related to the magnitude of magnetic reluctance and rigidity with greater freedom.

[0082] <7. Summary>

[0083] As described above, in the motor 1 according to the above embodiment, the magnitude of the magnetic reluctance from the circumferential tip of the flange portion 132 extending towards the second tooth 13H of the first tooth 13G to the circumferential center of the extension portion 131 of the first tooth 13G is the first magnetic reluctance R1, and the magnitude of the magnetic reluctance from the circumferential tip of the flange portion 132 extending towards the third tooth 13F of the first tooth 13G to the circumferential center of the extension portion 131 of the first tooth 13G is the second magnetic reluctance R2. The magnitude of the second magnetic reluctance R2 is smaller than the magnitude of the first magnetic reluctance R1 (R1 > R2). In this way, it is difficult for a short circuit of magnetic flux to occur between adjacent teeth 13 where in-phase coils 14 are formed, thereby suppressing the generation of magnetic flux paths that circulate only within the stator core 11. Therefore, the increase of induced voltage can be suppressed, thereby expanding the operating range.

[0084] As described above, in the prior art, to reduce leakage flux, the following measures are considered: on the side adjacent to the coil in phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively short; on the side adjacent to the coil out of phase with the coil formed on the teeth, the circumferential protrusion length of the flange is relatively long. With such a structure, the space for inserting the nozzle for winding is limited by a narrower slot, while the effect of the flange in holding the winding is limited by a wider slot, resulting in significant constraints during production and decreased productivity. In contrast, in the motor 1 according to the above embodiment, all teeth 13 have flange portions 132 and extension portions 131 of the same width, and the slots between the teeth 13 are all of the same shape and size. Therefore, the winding can be wound in the same manner for all teeth 13, improving productivity.

[0085] <8. Variations>

[0086] The exemplary embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments.

[0087] When the through hole located in the first flange is viewed axially, its shape is not limited to a triangular shape. Alternatively, the through hole can be circular, rectangular, or elliptical when viewed axially.

[0088] The gap provided in the first flange is not limited to a through hole. Alternatively, a cutout serving as a gap can be provided in the first flange.

[0089] Both a gap and a riveting part can be provided in the first flange portion.

[0090] In the motor 1 of the above embodiment, the states in which coils 14 of the same phase are formed on adjacent teeth 13 in the circumferential direction and the states in which coils 14 of different phase are formed on adjacent teeth 13 in the circumferential direction alternate in the circumferential direction, but are not limited to this. Alternatively, the states in which coils 14 of the same phase are formed on adjacent teeth 13 in the circumferential direction can be repeated multiple times in the circumferential direction. That is, the motor 1 is not limited to a 10-pole, 12-slot motor. Alternatively, for example, it can be an 8-pole, 9-slot, 10-pole, 9-slot, or 14-pole, 12-slot motor.

[0091] The electric motor 1 described in the above embodiment has a stator arranged on the outer periphery and a rotor arranged on the inner periphery, but is not limited thereto. Alternatively, the electric motor can be made into an "outer rotor type" with a rotor arranged on the outer periphery and a stator arranged on the inner periphery.

[0092] Within the scope of not creating contradictions, the elements appearing in the above-described implementation methods and variations can also be appropriately combined.

[0093] -Industry Applicability-

[0094] This disclosure is useful for electric motors.

[0095] - Symbol Explanation -

[0096] 1. Electric motor

[0097] 10 stators

[0098] 11. Stator core

[0099] 12 Magnetic Yoke

[0100] 13 teeth

[0101] 13F Third Tooth

[0102] 13G First Tooth

[0103] 13H Second Tooth

[0104] 14 coils

[0105] 20 rotors

[0106] 21 Permanent Magnets

[0107] 30 Rotation axis

[0108] 131 Extension

[0109] 132GF First flange

[0110] 132GR Second Flange

[0111] 133 Through hole (hole)

[0112] 233 Riveting section

[0113] 333 First Through Hole

[0114] 334 Second Through Hole

[0115] 433 Through Hole

[0116] P Electromagnetic steel sheet (laminated sheet)

[0117] P1 First Electromagnetic Steel Plate (First Layer of Laminated Plate)

[0118] P2 Second Electromagnetic Steel Plate (Second Layer)

Claims

1. An electric motor (1), characterized in that: The electric motor (1) includes: Rotor (20), which rotates freely about a rotation axis (30); and The stator (10) and the rotor (20) are arranged radially opposite each other. The stator (10) includes a stator core (11), the stator core (11) comprising: A magnetic yoke in an approximately ring shape (12); and Multiple teeth (13) extend radially from the yoke (12) toward the rotor (20) and are spaced apart circumferentially along the yoke (12). Each of the plurality of teeth (13) has: Extension (131), wherein a coil (14) is formed by winding a coil in a concentrated winding manner; and A flange portion (132) extends radially from the top end of the extension portion (131) toward both circumferential sides. Among the plurality of teeth (13) are: First tooth (13G); The second tooth (13H) is circumferentially adjacent to the first tooth (13G), and a coil (14) in phase with the coil (14) formed on the second tooth (13H) is formed thereon; and The third tooth (13F) is circumferentially adjacent to the first tooth (13G), and a coil (14) that is out of phase with the coil (14) formed on the third tooth (13F) is formed on the first tooth (13G). The flange portion (132) has: The first flange portion (132GF) of the first tooth (13G) extends toward the second tooth (13H); and The second flange portion (132GR) of the first tooth (13G) extends toward the third tooth (13F). The magnitude of the magnetic reluctance from the circumferential tip of the first flange (132GF) to the circumferential center of the extension (131) of the first tooth (13G) is the first magnetic reluctance. The magnitude of the magnetic resistance from the top circumferential portion of the second flange (132GR) to the circumferential center of the extension (131) of the first tooth (13G) is the second magnetic resistance, which is smaller than the magnitude of the first magnetic resistance.

2. The electric motor (1) according to claim 1, characterized in that: A gap is formed in the first flange portion (132GF), while no gap is formed in the second flange portion (132GR).

3. The electric motor (1) according to claim 2, characterized in that: The void formed in the first flange portion (132GF) is a plurality of holes (133).

4. The electric motor (1) according to claim 1, characterized in that: The first flange (132GF) contains a material with a lower permeability than the material constituting the second flange (132GR).

5. The electric motor (1) according to any one of claims 1 to 4, characterized in that: The stator core (11) is formed by stacking multiple laminated plates (P). A riveting portion (233) is provided on the first flange portion (132GF) to fasten the plurality of laminated plates (P) together.

6. The electric motor (1) according to claim 1, characterized in that: The stator core (11) is formed by stacking multiple laminated plates (P). The plurality of laminates (P) include: The first laminate (P1) has a first flange portion (132GF) whose magnetic reluctance is smaller than that of the second flange portion (132GR) of the first laminate (P1); and The second laminate (P2) has the same magnetic reluctance as the first flange portion (132GF) and the second flange portion (132GR). The first stacked board (P1) and the second stacked board (P2) are stacked alternately at predetermined intervals.

7. The electric motor (1) according to claim 1, characterized in that: The stator core (11) is formed by stacking multiple laminated plates (P). The plurality of laminates (P) include: The first laminate (P1) has a first flange portion (132GF) whose magnetic reluctance is smaller than that of the second flange portion (132GR) of the first laminate (P1); and The second laminate (P2) has the same magnetic reluctance as the first flange portion (132GF) and the second flange portion (132GR). The first laminate (P1) and the second laminate (P2) are laminated in the desired order.

8. The electric motor (1) according to claim 1, characterized in that: The plurality of teeth (13) are arranged at certain intervals along the circumference of the magnetic yoke (12). When viewed along the axial direction, all of the teeth (13) have the same shape. When viewed along the axial direction, the teeth (13) have a shape that is linearly symmetrical with respect to the center line of the tooth width direction.

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