Stator and motor

Abstract

The present invention provides a stator and a motor. The stator (14) comprises: a first wiring (26) connected to the front end coil (24U L , 24V L , 24W L ) of the coil end and the power line (16); and a second wiring (28) which is at the front end of the coil (24U L , 24V L , 24W L ) through the coil with the lowest turns ratio (24U E , 24V E , 24W E ) The part with fewer turns (SPT) is connected to the last coil (24U E , 24V E , 24W E ) of the coil end and the neutral point (NP) on the power line (16) side.

Description

Technical Field

[0001] The invention relates to a stator and a motor. Background Art

[0002] A three-phase motor is known as a motor. The three-phase motor includes coils of U phase, V phase, and W phase provided on a stator core, and power lines for supplying current to the coils.

[0003] Japanese Patent Application Publication No. 2016-039642 discloses a rotating electrical machine in which each neutral point lead wire and power supply side lead wire of a three-phase coil wound around a tooth portion extends toward one axial side of a stator core to connect a neutral point joint portion and a three-phase power supply portion on the axial side. Summary of the invention

[0004] However, in the above-mentioned rotating electrical machine, the coils of each phase must be connected to each other on one axial side of the stator core, and therefore the wiring relationship on the axial side tends to occupy a large amount.

[0005] Therefore, it is considered to arrange the power supply side lead wire and the three-phase power supply part on one axial side of the stator core, and arrange the neutral point side lead wire and the neutral point joint part on the other axial side of the stator core. In this way, the occupation of the wiring relationship on one axial side becomes smaller.

[0006] However, each power supply side lead wire of the three-phase coil connected to the three-phase power supply is arranged on the axial side of one side of the stator core, and each neutral point side lead wire of the three-phase coil is arranged on the axial side of the other side of the stator core. Therefore, for each power supply side lead wire of the three-phase coil connected to the three-phase power supply, the number of turns is locally reduced compared with the three-phase coil not connected to the three-phase power supply. Therefore, torque fluctuation and imbalance of magnetic attraction are easily generated, and there is a tendency for the characteristics of the motor to deteriorate.

[0007] Therefore, an object of the present invention is to provide a stator and a motor capable of suppressing deterioration of the characteristics of the motor.

[0008] The first scheme of the present invention is a stator, which has multiple coils. The multiple coils are arranged on multiple teeth protruding from the inner circumferential surface of the annular core body toward the central axis of the above-mentioned core body, and correspond to multiple phases respectively. With the above-mentioned teeth as a reference, the coil ends of the multiple coils corresponding to the multiple phases are connected to each other on the side opposite to the power line side of the phase current flowing to the above-mentioned multiple coils corresponding to the multiple phases, so that the multiple coils are connected in series to each of the above-mentioned phases. The above-mentioned stator is characterized in that, among the above-mentioned multiple coils corresponding to each of the above-mentioned phases connected in series, the coil end of the frontmost coil is located on the above-mentioned power line side, and the coil end of the last coil is located on the opposite side. The above-mentioned stator has: a first wiring, which connects the coil end of the above-mentioned frontmost coil and the above-mentioned power line; and a second wiring, which passes through a portion of the above-mentioned frontmost coil with fewer turns than the above-mentioned last coil, and connects the coil end of the above-mentioned last coil and the neutral point on the above-mentioned power line side.

[0009] A second aspect of the present invention is an electric motor including the above-mentioned stator and a rotor.

[0010] According to the present invention, the second wiring passes through the portion of the frontmost coil having fewer turns than the rearmost coil, so that torque ripple and imbalance of magnetic attraction force are less likely to occur, and deterioration of the characteristics of the motor can be suppressed.

[0011] The above-mentioned objects, features and advantages will be easily understood from the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram showing a part of the cross section of the motor.

[0013] Figure 2 This is a schematic diagram showing the connection state of multiple coils.

[0014] Figure 3 This is a diagram conceptually showing the difference in the number of turns between the frontmost coil and the rearmost coil.

[0015] Figure 4 It is a schematic diagram showing a part of the stator core. DETAILED DESCRIPTION

[0016] In the present invention, preferred embodiments are disclosed and described in detail below with reference to the drawings.

[0017] [Implementation Method]

[0018] Figure 11 is a schematic diagram showing a part of the cross section of the motor 10. The motor 10 is, for example, an inner rotor type motor, and includes: a rotor 12 having a rotor core 12A and a magnet 12B; a stator 14 provided outside the rotor 12; a power line 16 for supplying current to the stator 14; and a center point not shown.

[0019] The stator 14 includes a housing 20, a stator core 22, and a coil 24. The housing 20 is a resin member for accommodating the stator core 22, the coil 24, etc., and is formed in a substantially cylindrical shape.

[0020] The stator core 22 is a member made of an iron-based metal and is arranged around the rotation axis AX of the electric motor 10, and is fixed to the housing 20. The stator core 22 includes a core body 22A and a plurality of teeth 22B.

[0021] The core body 22A is formed into a ring shape, and the axis (central axis) of the core body 22A formed into a ring shape is consistent with the rotation axis AX of the motor 10. In addition, the core body 22A can also be formed into a ring shape by joining a plurality of split core bodies in the circumferential direction. A plurality of tooth portions 22B are arranged at intervals along the circumferential direction of the core body 22A. A plurality of tooth portions 22B protrude from the inner circumferential surface of the core body 22A toward the axis (central axis) side of the core body 22A.

[0022] The coil 24 has a plurality of phases corresponding to the plurality of phases. The number of phases of the coil 24 is generally three phases, namely, the U phase, the V phase, and the W phase, but the number of phases of the coil 24 may be other than three phases. The plurality of coils 24 corresponding to the plurality of phases are provided on the plurality of teeth 22B. Specifically, for each of the plurality of teeth 22B, one coil 24 is wound in a densely wound manner. In addition, in the present embodiment, the number of phases of the coil 24 is set to three phases, namely, the U phase, the V phase, and the W phase.

[0023] A power line 16 is provided on one side of a pair of coil terminals 24E protruding from the axial end of the stator core 22 in each of the coils 24 wound around the plurality of teeth 22B. The power line 16 is used to flow phase current to the plurality of coils 24 corresponding to each other, and in the present embodiment, there is a U-phase power line 16U for flowing a U-phase current, a V-phase power line 16V for flowing a V-phase current, and a W-phase power line 16W for flowing a W-phase current.

[0024] Figure 2 Schematic diagram showing the connection state of the plurality of coils 24 . Figure 2 The “△” in FIG. 2 represents the winding direction of the coil 24. Figure 2 The “▲” of the display will be described later.

[0025] For each phase, the plurality of coils 24 are connected in series. That is, the coil ends of the plurality of coils 24U corresponding to U are connected to each other, so that the plurality of coils 24U corresponding to U are connected in series. On the other hand, the coil ends of the plurality of coils 24V corresponding to V are connected to each other, so that the plurality of coils 24V corresponding to V are connected in series. On the other hand, the coil ends of the plurality of coils 24W corresponding to W are connected to each other, so that the plurality of coils 24W corresponding to W are connected in series.

[0026] The connection parts CNU of the coils 24U corresponding to U, the connection parts CNV of the coils 24V corresponding to V, and the connection parts CNW of the coils 24W corresponding to W are respectively formed by the teeth 22B ( Figure 1 ) is located on the side opposite to the power line 16. Thus, compared with a case where each connection portion CNU, CNV, CNW is located on the power line 16 side, the amount of wiring relationship occupied on the power line 16 side can be reduced.

[0027] Here, the coil 24U, 24V, 24W at one end of the pair of coils 24U, 24V, 24W corresponding to the plurality of phases connected in series is set as the frontmost coil 24U. L , 24V L , 24W L In addition, the coil 24U, 24V, 24W at the other end of the plurality of coils 24U, 24V, 24W corresponding to the plurality of phases connected in series is set as the last coil 24U. E , 24V E , 24W E .

[0028] The front coil 24U L , 24V L , 24W L The front end of each coil is formed by the tooth portion 22B ( Figure 1 ) is used as a reference and is located on the power line 16 side. In addition, the front end coil end is the front end coil 24U L , 24V L , 24W L The coil end of each pair of coil ends is the coil end on the side not connected to the coil end of the second coil 24U, 24V, 24W.

[0029] Each of the frontmost coil ends is connected to the power line 16 in phase. That is, the stator 14 of the present embodiment includes the first wiring 26 that connects the frontmost coil end located on the power line 16 side and the power line 16 .

[0030] In this embodiment, the first wiring 26 has: a U-phase wiring 26U connecting the front end coil end of the U phase and the U-phase power line 16U; a V-phase wiring 26V connecting the front end coil end of the V phase and the V-phase power line 16V; and a W-phase wiring 26W connecting the front end coil end of the W phase and the W-phase power line 16W.

[0031] On the other hand, the last coil 24U E , 24V E , 24W E The last coil end of each is formed by the tooth portion 22B ( Figure 1 ) is the reference, located on the side opposite to the power line 16, and is the last coil 24U E , 24V E , 24W E Of the pair of coil ends, the coil end is the one that is not connected to the coil end of the penultimate coil 24U, 24V, 24W.

[0032] Figure 3 This is a conceptual representation of the front end coil 24U L And the last coil 24U E In addition, for the sake of convenience, in Figure 3 Only the front end coil 24U of the U phase is shown. L And the last coil 24U E However, for the front end coil of the V phase, 24V L And the last coil 24V E The front end coil of the W phase is 24W L And the last coil 24W E , and also with the U-phase front end coil 24U L And the last coil 24U E same.

[0033] That is, at the end of the coil 24U E , 24V E , 24W E In the embodiment, the two sides of a pair of coil ends extend in the opposite direction to the power line 16 side, and the directions in which the pair of coil ends extend are not opposite. E , 24V E , 24W E The number of turns is the same.

[0034] In contrast, the frontmost coil 24U L , 24V L , 24W LIn the embodiment, one of the pair of coil ends (the frontmost coil end) extends toward the power line 16, and the other of the pair of coil ends extends in the opposite direction to the power line 16. Therefore, the frontmost coil 24U L , 24V L , 24W L In the process, a small number of turns of SPT are generated.

[0035] The SPT with fewer turns is the coil 24U at the front end. L , 24V L , 24W L The coil with the lowest turn ratio in the middle is 24U E , 24V E , 24W E The small part, Figure 2 In the small-turn portion SPT, torque ripple and imbalance of magnetic attraction are likely to occur as described above.

[0036] Therefore, in this embodiment, if Figure 2 As shown, the neutral point NP is provided on the power line 16 side, and the neutral point NP and the last coil end of each phase located on the side opposite to the power line 16 side are connected by passing through the small turn portion SPT.

[0037] That is, the stator 14 of the present embodiment has the second wiring 28 that passes through the small-turn portion SPT and connects the last coil end and the neutral point NP. The second wiring 28 may be covered with an insulating tube at least at a portion passing through the small-turn portion SPT.

[0038] In the present embodiment, the second wiring 28 includes a U-phase wiring 28U connecting the last coil end of the U phase and the neutral point NP, a V-phase wiring 28V connecting the last coil end of the V phase and the neutral point NP, and a W-phase wiring 28W connecting the last coil end of the W phase and the neutral point NP. The neutral point NP is a connection point connecting each of the U phase, the V phase, and the W phase.

[0039] In this way, the stator 14 of this embodiment connects the neutral point NP located on the power line 16 side and the last coil end located on the side opposite to the power line 16 side via the small number of turns portion SPT, so that it is difficult to generate torque ripple and imbalance of magnetic attraction. Therefore, in this embodiment, the deterioration of the characteristics of the motor 10 can be suppressed.

[0040] Figure 4 2 is a schematic diagram showing a portion of the stator core 22. Figure 4 The diagram shows a pair of coil terminals 24E ( Figure 1 ) to observe the stator core 22. Figure 4, the coil 24, the power line 16, etc. are omitted, and only a portion of the stator core 22 is shown.

[0041] In the present embodiment, the plurality of teeth 22B include first teeth 22B1 and second teeth 22B2. The first teeth 22B1 and the second teeth 22B2 are alternately arranged along the circumferential direction of the core body 22A.

[0042] The cross-section of the first tooth portion 22B1 in a direction perpendicular to the axis (central axis) of the core body 22A is rectangular. The cross-section of the second tooth portion 22B2 in a direction perpendicular to the axis (central axis) of the core body 22A is trapezoidal, and the cross-sectional area of ​​the cross-section is larger than that of the first tooth portion 22B1.

[0043] A second wiring 28 ( Figure 2 ) passes through the passage 30. Specifically, in the supply of the front end coil 24U corresponding to each of the plurality of phases. L , 24V L , 24W L ( Figure 2 ) A passage 30 is formed at the boundary portion between each of the second teeth 22B2 wound around the core body 22A. That is, a passage 30 is formed for each of a plurality of phases, and the U-phase wiring 28U, the V-phase wiring 28V, and the W-phase wiring 28W ( Figure 2 ) are all passed through. In addition, Figure 4 In the figure, for the convenience of explanation, only one passage 30 is shown.

[0044] Thus, by forming the passage 30 for passing the second wiring 28 in the stator core 22, it is easy to pass the second wiring 28 through the small number of turns portion SPT. In addition, the passage 30 is formed at the boundary portion between the second tooth portion 22B2, which is larger than the first tooth portion 22B1, and the core body 22A, thereby suppressing the reduction in strength of the stator core 22 and suppressing the reduction in torque due to magnetic saturation at high currents, compared with the case where the passage 30 is formed at the boundary portion between the first tooth portion 22B1 and the core body 22A.

[0045] In the present embodiment, the passage 30 is formed as a depression on the surface of the boundary portion between the core body 22A and one second tooth portion 22B2. This allows the second wiring 28 to be brought close to the small turn portion SPT, further reducing the occurrence of torque ripple and imbalance in magnetic attraction.

[0046] [Variation]

[0047] The above embodiment is described using an example of the present invention, and the technical scope of the present invention is not limited to the scope described in the above embodiment. Of course, various changes or improvements can be applied to the above embodiment. According to the description of the claims, the method in which various changes or improvements are applied also belongs to the technical scope of the present invention.

[0048] In the above-described embodiment, the plurality of teeth portions 22B include the first teeth portion 22B1 and the second teeth portion 22B2 , but may include only the first teeth portion 22B1 or the second teeth portion 22B2 .

[0049] In the above embodiment, the passage 30 is formed at the boundary between the core body 22A and the first tooth portion 22B (second tooth portion 22B2 ), but may be formed only in the core body 22A or only in the tooth portion 22 .

[0050] In the above-described embodiment, the passage 30 is a depression formed on the surface of the stator core 22 , but may be a through hole.

[0051] Furthermore, the above-described embodiments and modifications may be arbitrarily combined within a range where no contradiction occurs.

[0052] [The present invention]

[0053] The invention that can be grasped from the above-mentioned embodiment and modified examples will be described below.

[0054] (First Invention)

[0055] The first invention is a stator 14, which has a plurality of teeth 22B protruding from the inner circumference of an annular core body 22A toward the central axis of the core body 22A and a plurality of coils 24U, 24V, 24W corresponding to the plurality of phases, respectively. With the teeth 22B as a reference, on the side opposite to the power line 16 side through which phase current flows to the plurality of coils 24U, 24V, 24W corresponding to the plurality of phases, the coil ends of the plurality of coils 24U, 24V, 24W corresponding to the plurality of phases are connected to each other, so that the plurality of coils 24U, 24V, 24W are connected in series in each phase.

[0056] The frontmost coil 24U is connected in series with the corresponding plurality of coils 24U, 24V, and 24W. L , 24V L , 24W L The coil end is located on the power line 16 side, and the last coil 24U E , 24V E , 24W E The coil ends are located on opposite sides.

[0057] The stator 14 has a first wiring 26 that connects the coil 24U at the front end. L, 24V L , 24W L and a second wiring 28, which is at the front end of the coil 24U L , 24V L , 24W L Pass through the coil 24U at the end of the turns ratio E , 24V E , 24W E The SPT of the part with fewer turns is connected to the last coil 24U E , 24V E , 24W E The coil end and the neutral point NP on the power line 16 side.

[0058] In such a stator 14, the second wiring 28 is provided at the frontmost coil 24U. L , 24V L , 24W L Pass through the coil 24U at the end of the turns ratio E , 24V E , 24W E The small portion (small number of turns portion SPT) makes it difficult for torque ripple and imbalance of magnetic attraction to occur, and it is possible to suppress degradation of the characteristics of the motor 10.

[0059] A passage 30 for passing the second wiring 28 may be formed in at least one of the core body 22A and one of the teeth 22B. This allows the second wiring 28 to easily pass through the portion with a small number of turns (small number of turns portion SPT).

[0060] The passage 30 may be a depression formed on the surface of the boundary between the core body 22A and one tooth portion 22B. This allows the second wiring 28 to be brought closer to the portion with fewer turns (fewer turns portion SPT) to further reduce the occurrence of torque ripple and imbalance in magnetic attraction.

[0061] The plurality of teeth 22B include a first tooth 22B1 and a second tooth 22B2, wherein the cross-sectional area of ​​the second tooth 22B2 in a direction perpendicular to the central axis of the core body 22A is larger than that of the first tooth 22B1, and the passage 30 may be formed at least in the second tooth 22B2. Thus, compared with the case where the passage 30 is formed in the first tooth 22B1, it is possible to suppress the reduction in the strength of the stator core 22, and also suppress the reduction in torque due to magnetic saturation at high current.

[0062] (Second Invention)

[0063] The second invention is an electric motor 10 including the above-mentioned stator 14 and the rotor 12. In the electric motor 10, by including the above-mentioned stator 14, it is possible to suppress deterioration of the characteristics of the electric motor 10.

Claims

1. A stator comprising a plurality of coils, the plurality of coils being provided on a plurality of teeth protruding from an inner peripheral surface of an annular core body toward a central axis of the core body and corresponding to a plurality of phases, respectively; With the teeth as a reference, coil ends of the plurality of coils corresponding to the plurality of phases are connected to each other on the side opposite to the power line side through which the phase current flows to the plurality of coils corresponding to the plurality of phases, so that the plurality of coils are connected in series to each of the phases. The above stator is characterized in that: Among the plurality of coils corresponding to the above mentioned ones connected in series, the coil end of the frontmost coil is located on the power line side, and the coil end of the rearmost coil is located on the opposite side. The above stator has: A first wiring connecting a coil end of the frontmost coil and the power line; and The second wiring passes through a portion where the number of turns of the foremost coil is smaller than that of the last coil, and connects a coil end of the last coil and a neutral point on the power line side.

2. The stator according to claim 1, characterized in that: A passage for passing the second wiring is formed in at least one of the core body and the one of the teeth.

3. The stator according to claim 2, characterized in that: The passage is a depression formed on a surface of a boundary portion between the core body and one of the teeth.

4. The stator according to claim 1, characterized in that: The plurality of teeth include a first tooth and a second tooth, wherein the second tooth has a larger cross-sectional area in a direction perpendicular to the central axis of the core body than the first tooth. A passage for passing the second wiring is formed in at least one of the second tooth portions.

5. The stator according to claim 4, characterized in that: The passage is a depression formed on a surface of a boundary portion between the core body and one of the second teeth.

6. An electric motor, characterized in that: A stator and a rotor according to any one of claims 1 to 5 are provided.

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