Electric motor, blower, and air conditioning device

Abstract

This electric motor has: a rotor that can rotate around a rotary shaft; and a stator having a stator core that faces the rotor in the radial direction centered on the rotary shaft, and a coil that is wound around the stator core. The rotor protrudes from the stator core from at least one side of the rotary shaft in the axial direction. The stator core has: a yoke that extends in the circumferential direction centered on the rotary shaft; a coil winding part that extends from the yoke toward the rotor and around which the coil is wound; and a tooth tip part that is provided at the tip of the coil winding part and faces the rotor. The stator has a magnetic flux capturing member at least at one end of the tooth tip part in the axial direction. A cross-sectional area A in a plane of the magnetic flux capturing member that is orthogonal to the rotary shaft, a cross-sectional area B in a plane of the coil winding part that is orthogonal to the radial direction, and a cross-sectional area C in a plane of the yoke that is orthogonal to the circumferential direction satisfy A < B and A < C.

Description

Electric motors, fans and air conditioners

[0001] The present disclosure relates to an electric motor, a blower, and an air conditioning device.

[0002] In the past, electric motors have been known in which the axial length of the stator core is shorter than the axial length of the rotor, and it has been proposed to attach magnetic pieces to the axial end faces of the stator core in order to capture magnetic flux from the rotor (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2009-038904 (see FIGS. 2(a) and 2(b))

[0004] In this case, magnetic flux flows into the stator core from both the surface of the stator core facing the rotor and the magnetic pieces. This increases the magnetic flux density in the stator core, which can lead to magnetic saturation. When magnetic saturation occurs in the stator core, the effective magnetic flux linking the coils decreases, resulting in a decrease in motor efficiency.

[0005] The present disclosure is directed to reducing magnetic saturation in a stator core.

[0006] The electric motor disclosed herein includes a rotor rotatable about a rotation axis, a stator core facing the rotor in a radial direction about the rotation axis, and a stator having a coil wound around the stator core. The rotor protrudes from the stator core on at least one side in the axial direction of the rotation axis. The stator core has a yoke extending in a circumferential direction about the rotation axis, a coil winding portion extending from the yoke toward the rotor and around which a coil is wound, and tooth tips provided at the tips of the coil winding portions and facing the rotor. The stator has a magnetic flux take-in member at at least one axial end of the tooth tips. A cross-sectional area A of the magnetic flux take-in member in a plane perpendicular to the rotation axis, a cross-sectional area B of the coil winding portion in a plane perpendicular to the radial direction, and a cross-sectional area C of the yoke in a plane perpendicular to the circumferential direction satisfy A<B and A<C.

[0007] According to the present disclosure, the cross-sectional areas A, B, and C satisfy the above-mentioned A<B and A<C, so that magnetic saturation in the stator core can be suppressed and the efficiency of the electric motor can be improved.

[0008] FIG. 1 is a cross-sectional view showing an electric motor according to a first embodiment. FIG. 2 is a cross-sectional view showing the electric motor according to the first embodiment, with the molded resin portion and the coils omitted. FIG. 3 is a perspective view showing a stator core and magnetic flux take-up member according to the first embodiment. FIG. 4 is a perspective view showing a part of the stator core and the magnetic flux take-up member according to the first embodiment. FIG. 5 is a plan view (A) showing a part of the stator core and the magnetic flux take-up member according to the first embodiment, and FIG. 6 is a schematic view (B) showing a holding structure for the magnetic flux take-up member. FIG. 6 is a schematic view showing a magnetic path in the stator core according to the first embodiment. FIG. 7 is a front view of the stator core according to the first embodiment, as seen from the rotor side. FIG. 8 is a schematic view (A), (B), and (C) showing a cross-sectional area A of the magnetic flux take-up member, a cross-sectional area B of the coil winding portion, and a cross-sectional area C of the yoke according to the first embodiment. FIG. 9 is a schematic view showing a cross-sectional area E1 of the coil winding portion and a cross-sectional area E2 of the tooth tip portion of the stator core according to the first embodiment. FIG. 10 is a cross-sectional view showing an example of a configuration of the magnetic flux take-up member according to the first embodiment, together with surrounding members. 19A is a cross-sectional view showing another example of the configuration of the magnetic flux taker of the first embodiment together with surrounding members, FIG. 19B is a perspective view showing the magnetic flux taker, and FIG. 19C is a schematic view showing a configuration for integrating laminated elements of the magnetic flux taker. FIG. 19B is a flowchart showing a method for manufacturing the electric motor of the first embodiment. FIG. 19C is a cross-sectional view showing another example of the configuration of the electric motor of the first embodiment. FIG. 19C is a cross-sectional view showing a part of the stator core and the magnetic flux taker of the electric motor of FIG. 13. FIG. 19C is a plan view showing the stator core, magnetic flux taker, and rotor of the second embodiment. FIG. 19D is a view of the stator of the second embodiment as seen from the rotor side. FIG. 19A is a view showing the opposing surfaces of the magnetic flux taker of the second embodiment, and FIG. 19B is a view showing the opposing surfaces of the connecting portion. FIG. 19A is a view showing the cross-sectional shape of the magnetic flux taker of the second embodiment, and FIG. 19B is a view showing the cross-sectional shape of the connecting portion. FIG. 19B is a cross-sectional view taken along line 19A-19A in FIG. 16 and along line 19B-19B in FIG. 16, showing an example of the configuration of the magnetic flux taker of the second embodiment. 16A and 16B are cross-sectional views taken along line 19A-19A and line 19B-19B, respectively, showing another example of the configuration of the magnetic flux taker of embodiment 2. FIG. 16A is a plan view showing a stator core, magnetic flux taker, and rotor of a modified example of embodiment 2. FIG. 16B is a cross-sectional view showing a connecting portion of the magnetic flux taker of a modified example of embodiment 2. FIG. 16B is a plan view showing a stator core, magnetic flux taker, and rotor of embodiment 3.Fig. 10 is a flowchart showing a method for manufacturing an electric motor according to embodiment 3. Fig. 11 is a plan view showing a stator core, a magnetic flux absorber, and a rotor according to embodiment 4. Fig. 12 is a plan view showing steel plates constituting the stator core according to embodiment 4. Fig. 13 is a cross-sectional view showing an electric motor according to embodiment 5. Fig. 14 is a diagram showing an air conditioning device to which the electric motors of each embodiment and modified example can be applied (A), and a diagram showing an outdoor unit of the air conditioning device (B).

[0009] Embodiment 1. <Configuration of electric motor> Fig. 1 is a cross-sectional view showing an electric motor 1 according to embodiment 1. As shown in Fig. 1, the electric motor 1 has a rotating shaft 15, a rotor 10 attached to the rotating shaft 15, and a stator 2 surrounding the rotor 10 via an air gap. The rotor 10 and the rotating shaft 15 are collectively referred to as a rotor unit 13.

[0010] The rotation axis Ax of the rotating shaft 15 defines the center of rotation of the rotor 10. In the following, the direction of the rotation axis Ax will be referred to as the "axial direction." The radial direction centered on the rotation axis Ax will be referred to as the "radial direction." The circumferential direction centered on the rotation axis Ax will be referred to as the "circumferential direction."

[0011] <Configuration of Rotor> Fig. 2 is a cross-sectional view of the electric motor 1 taken along a plane perpendicular to the rotation axis Ax. A molded resin portion 50 and coils 25, which will be described later, are omitted from Fig. 2. As shown in Fig. 2, the rotor 10 is a cylindrical member fixed to the rotating shaft 15. An outer peripheral surface 10a of the rotor 10 faces an inner peripheral surface of the stator core 20.

[0012] The rotor 10 is composed of permanent magnetic poles 11 and 12. The permanent magnetic poles 11 and 12 are arranged alternately in the circumferential direction. The permanent magnetic pole 11 has a north pole on the outer peripheral surface 10a side, and the permanent magnetic pole 12 has a south pole on the outer peripheral surface 10a side.

[0013] The rotor 10 has two permanent magnetic poles 11 and two permanent magnetic poles 12, but may have at least one each of the permanent magnetic poles 11 and 12. The rotor 10 may also have permanent magnetic poles attached to a rotor core.

[0014] 1, the axial length L1 of the rotor 10 is longer than the axial length L2 of a stator core 20 (described later) of the stator 2. That is, the rotor 10 protrudes from the stator core 20 on at least one side (both sides in this case) in the axial direction.

[0015] <Configuration of the stator> The stator 2 has a stator core 20 radially facing the rotor 10, an insulating portion 40 as a first insulating member provided on the stator core 20, a coil 25 wound around the insulating portion 40, a magnetic flux intake member 31 provided on the end face of the stator core 20, and a molded resin portion 50 as an outer casing member covering these.

[0016] The molded resin portion 50 is made of a resin such as a thermosetting resin and is also referred to as a second insulating member. The molded resin portion 50 is formed to cover the stator core 20, the coil 25, the magnetic flux intake member 31, and the insulating portion 40.

[0017] The rotating shaft 15 protrudes from the molded resin portion 50 to one side in the axial direction. The protruding side of the rotating shaft 15 is referred to as the "load side," and the opposite side of the rotating shaft 15 to the load side is referred to as the "anti-load side."

[0018] The molded resin part 50 has an opening 50a on the load side and an opening 50b on the anti-load side. A bracket 51 is attached to the opening 50a of the molded resin part 50, and a bracket 52 is attached to the opening 50b. The bracket 51 has a through hole through which the rotating shaft 15 passes.

[0019] Bracket 51 holds bearing 16, and bracket 52 holds bearing 17. Bearings 16 and 17 rotatably support rotating shaft 15. Legs 54 are provided on the outer periphery of molded resin part 50 for attaching electric motor 1 to a motor support or the like.

[0020] The stator core 20 is an annular member that radially surrounds the rotor 10. The stator core 20 is formed of a laminated body in which steel plates 101 (FIG. 10) are stacked in the axial direction. The steel plates 101 are, for example, electromagnetic steel plates.

[0021] 2, the stator core 20 has an annular yoke 21 centered on the rotation axis Ax, N coil winding portions 22 extending from the yoke 21 toward the rotor 10, and tooth tips 23 provided at the tip of each coil winding portion 22 and facing the rotor 10. N is an integer of 2 or greater, and is 9 here, but is not limited to 9. The coil winding portions 22 and the tooth tips 23 together are referred to as teeth.

[0022] The coil winding portions 22 are formed at equal intervals in the circumferential direction. Slots 24 are formed between adjacent coil winding portions 22. A coil 25 is wound around the coil winding portion 22 and accommodated in the slot 24.

[0023] The tooth tips 23 are formed at the tips of the coil winding portions 22, in this case, at the radially inner tips. The tooth tips 23 have a wider circumferential width than the coil winding portions 22. The number of tooth tips 23 is N, the same as the number of coil winding portions 22, and is nine in this case. The tooth tips 23 have opposing surfaces 23a (FIG. 3) that face the rotor 10.

[0024] The coil 25 (FIG. 1) is a copper wire or an aluminum wire. The coil 25 is wound around the coil winding portion 22 via an insulating portion 40. The coil 25 is wound by, for example, concentrated winding, but may also be wound by distributed winding.

[0025] The insulating portion 40 is formed of a thermoplastic resin such as PBT (polybutylene terephthalate). The insulating portion 40 is either integrally molded with the stator core 20 or formed by attaching a resin molded body to the stator core 20. The insulating portion 40 is also referred to as an insulator.

[0026] The insulating portion 40 has a wall portion 41 attached to the yoke 21, a body portion 42 attached to the coil winding portion 22, and a flange portion 43 attached to the tooth tip portion 23. The coil 25 ( FIG. 1 ) is wound around the body portion 42. The wall portion 41 guides the coil 25 from the radially outer side. The flange portion 43 guides the coil 25 from the radially inner side.

[0027] 3 is a perspective view showing the stator core 20. The yoke 21 of the stator core 20 has an inner periphery 21a facing the slots 24, an outer periphery 21b on the opposite side, and end faces 21c on both axial sides.

[0028] The coil winding portion 22 has end faces 22c on both axial sides and side end portions 22e on both circumferential sides. The outer end of the coil winding portion 22 is connected to the yoke 21, and the inner end is connected to the tooth tip portion 23.

[0029] Tooth tip 23 has a facing surface 23a facing rotor 10 (FIG. 2), a back surface 23b facing yoke 21, end surfaces 23c on both axial sides, and side end portions 23e on both circumferential sides.

[0030] A magnetic flux take-in member 31 is provided on at least one axial end face 23c of the tooth tip portion 23. In the example shown in Fig. 3, a magnetic flux take-in member 31 is provided on both end faces 23c of the tooth tip portion 23. In this case, the number of magnetic flux take-in members 31 is twice the number of the tooth tip portions 23 (i.e., 2N).

[0031] However, the magnetic flux intake members 31 may be provided only on one end surface 23c of the tooth tip portion 23 (see FIGS. 13 and 14). In this case, the number of magnetic flux intake members 31 is the same as the number of tooth tip portions 23 (i.e., N).

[0032] In Figure 3, the axial length of the magnetic flux intake member 31 provided on one end face 23c (upper face in Figure 3) of the tooth tip portion 23 is shown as being longer than the axial length of the magnetic flux intake member 31 provided on the other end face 23c (lower face in Figure 3), but these lengths can be set arbitrarily.

[0033] The magnetic flux take-in member 31 faces the rotor 10 (FIG. 2) in the radial direction. The magnetic flux take-in member 31 is made of a magnetic material, more specifically, a metal such as iron. As will be described later, the magnetic flux take-in member 31 takes in the magnetic flux of the rotor 10 and guides it to the stator core 20, and is therefore also called a magnetic flux guide or flux guide.

[0034] Fig. 4 is a perspective view showing a portion of the stator core 20 (more specifically, a portion including one coil winding portion 22 and one tooth tip portion 23) and the magnetic flux take-in member 31. Fig. 5(A) is a plan view showing a portion of the stator core 20 and the magnetic flux take-in member 31.

[0035] As shown in Figures 4 and 5(A), the magnetic flux intake member 31 has an opposing surface 31a facing the rotor 10, a back surface 31b facing the yoke 21, end surfaces 31c (Figure 4) on both axial sides, and side end portions 31e on both circumferential sides.

[0036] It is desirable that the radial position of the opposing surface 31a of the magnetic flux take-in member 31 coincides with the radial position of the opposing surface 23a of the tooth tip 23. Like the opposing surface 23a of the tooth tip 23, the opposing surface 31a of the magnetic flux take-in member 31 is exposed on the rotor 10 side from the molded resin part 50 (FIG. 1).

[0037] 5A, the opposing surface 31a of the magnetic flux intake member 31 has a curved shape such that the side facing the rotor 10 is concave. In other words, the opposing surface 31a is curved so that the distance between the opposing surface 31a and the rotor 10 is constant in the circumferential direction.

[0038] The back surface 31b of the magnetic flux intake member 31 has a curved shape similar to the opposing surface 31a. That is, the back surface 31b is curved so that the distance between the back surface 31b and the opposing surface 31a (i.e., the radial thickness of the magnetic flux intake member 31) is constant in the circumferential direction.

[0039] 5(B) is a cross-sectional view schematically showing the holding structure of the magnetic flux take-in member 31. The flange portion 43 of the insulating part 40 described above is located radially outward of the magnetic flux take-in member 31. The flange portion 43 is formed with a wall portion 43a that abuts against the side end portion 31e of the magnetic flux take-in member 31. The magnetic flux take-in member 31 is held by being sandwiched from both sides in the circumferential direction by the wall portions 43a of the insulating part 40.

[0040] 6 is a schematic diagram showing magnetic paths in the stator core 20. In the stator core 20, the opposing surfaces 23a of the tooth tips 23 face the rotor 10. In addition, the opposing surfaces 31a of the magnetic flux intake members 31 attached to the tooth tips 23 also face the rotor 10.

[0041] Magnetic flux F1 flows from the rotor 10 through the opposing surface 23a into the tooth tip 23 of the stator core 20. In addition, magnetic flux F2 that flows from the rotor 10 into the opposing surface 31a of the magnetic flux take-in member 31 also flows in the axial direction within the magnetic flux take-in member 31 and into the tooth tip 23. These magnetic fluxes F1 and F2 flow from the tooth tip 23 into the coil winding portion 22 and then flow within the coil winding portion 22 toward the yoke 21.

[0042] By providing the magnetic flux intake member 31, it is possible to take in a larger amount of magnetic flux from the rotor 10 into the stator core 20. In other words, it is possible to take in a larger amount of magnetic flux into the stator core 20 and link it to the coils 25.

[0043] 7 is a view of the stator core 20 as viewed from the rotor 10 side. The circumferential width of the coil winding portion 22 of the stator core 20 is narrower than the circumferential width of the tooth tips 23 and the magnetic flux take-in members 31. Magnetic fluxes F1 and F2 (FIG. 6) from the tooth tips 23 and the magnetic flux take-in members 31 flow into the coil winding portion 22, causing the magnetic flux density to increase in the coil winding portion 22.

[0044] An increase in magnetic flux density leads to an increase in iron loss. Furthermore, when magnetic saturation occurs in the coil winding portion 22, the magnetic flux linking the coil 25 decreases, and the efficiency of the electric motor decreases.

[0045] Furthermore, since the magnetic flux that has flowed through the coil winding portion 22 flows into the yoke 21, if there is a portion with a narrow cross-sectional area in the yoke 21, the magnetic flux density will increase in that portion, which may cause magnetic saturation in the yoke 21.

[0046] 8A is a schematic diagram illustrating the cross-sectional area A of the magnetic flux take-in member 31. The cross-sectional area A of the magnetic flux take-in member 31 is the cross-sectional area in a plane perpendicular to the axial direction. More specifically, the cross-sectional area A is the cross-sectional area of ​​the portion surrounded by the opposing surface 31 a, the back surface 31 b, and the side end portions 31 e on both sides in the circumferential direction of the magnetic flux take-in member 31.

[0047] In the example shown in Figure 8 (A), the cross-sectional area of ​​the tooth tip portion 23 in a plane perpendicular to the axial direction is constant regardless of the axial position, but if the cross-sectional area changes depending on the axial position, the smallest cross-sectional area is taken as cross-sectional area A.

[0048] 8(B) is a schematic diagram illustrating the cross-sectional area B of the coil winding portion 22. The cross-sectional area B of the coil winding portion 22 is the cross-sectional area in a plane perpendicular to the radial direction (i.e., the extension direction of the coil winding portion 22). More specifically, the cross-sectional area B is the cross-sectional area of ​​the portion surrounded by the end faces 22c on both axial sides of the coil winding portion 22 and the side end portions 22e on both circumferential sides.

[0049] In the example shown in Figure 8 (B), the cross-sectional area of ​​the coil winding portion 22 in a plane perpendicular to the radial direction is constant regardless of the radial position, but if the cross-sectional area changes depending on the radial position, the smallest cross-sectional area is taken as cross-sectional area B.

[0050] 8C is a schematic diagram illustrating the cross-sectional area C of the yoke 21. The cross-sectional area C of the yoke 21 is the cross-sectional area in a plane perpendicular to the circumferential direction (i.e., the extension direction of the yoke 21). More specifically, the cross-sectional area C is the cross-sectional area of ​​the portion surrounded by the inner periphery 21a, the outer periphery 21b, and the end faces 21c on both axial sides of the yoke 21.

[0051] Since the cross-sectional area varies depending on the circumferential position of the yoke 21, the smallest cross-sectional area is defined as the cross-sectional area C. Here, the area of ​​the boundary portion 21 e located midway between two circumferentially adjacent coil winding portions 22 (i.e., at the circumferential center of the slot 24) is defined as the cross-sectional area C.

[0052] The cross-sectional areas A, B, and C all correspond to the cross-sectional area in a plane perpendicular to the direction in which the magnetic flux flows.

[0053] The cross-sectional areas A, B, and C satisfy both A<B and A<C. That is, the cross-sectional area A in a plane perpendicular to the axial direction of the magnetic flux intake member 31 is smaller than the cross-sectional area B in a plane perpendicular to the radial direction of the coil winding portion 22, and is also smaller than the cross-sectional area C in a plane perpendicular to the circumferential direction of the yoke 21.

[0054] Since the cross-sectional area A of the magnetic flux intake member 31 is smaller than the cross-sectional area B of the coil winding portion 22 (A < B), the amount of magnetic flux flowing from the magnetic flux intake member 31 to the coil winding portion 22 is limited, the increase in magnetic flux density in the coil winding portion 22 is suppressed, and the occurrence of magnetic saturation is suppressed.

[0055] Furthermore, since the cross-sectional area A of the magnetic flux intake member 31 is smaller than the cross-sectional area C of the yoke 21 (A < C), the amount of magnetic flux flowing from the magnetic flux intake member 31 through the coil winding portion 22 into the yoke 21 is limited, thereby suppressing an increase in the magnetic flux density in the yoke 21 and preventing the occurrence of magnetic saturation.

[0056] 9 is a schematic diagram illustrating the cross-sectional area E1 of the coil winding portion 22 and the cross-sectional area E2 of the tooth tip portion 23 of the stator core 20. In Fig. 9, a radial line passing through the circumferential center of the coil winding portion 22 is defined as a center line T. A point on the center line T on the opposing surface 23a of the tooth tip portion 23 is defined as a tooth tip center F.

[0057] A first line G1 is a line that passes through the radially outer end 25a (i.e., the yoke 21 side) of the coil 25 wound around the coil winding portion 22 and is perpendicular to the center line T. A second line G2 is a line that passes through the radially inner end 25b (i.e., the rotor 10 side) of the coil 25 and is perpendicular to the center line T.

[0058] The distance between the first straight line G1 and the second straight line G2 is defined as a distance D1. The longer the distance D1, the more space is required for arranging the coil 25.

[0059] Meanwhile, the distance between the second straight line G2 and the tooth tip center F is defined as a distance D2. The longer the distance D2, the greater the amount of magnetic flux that can be taken in from the magnetic flux take-in member 31 to the tooth tip 23.

[0060] These distances D1 and D2 satisfy D1 > D2. As described above, increasing distance D2 is advantageous in increasing the magnetic flux taken in from magnetic flux take-in member 31 to stator core 20, but if distance D2 is increased without increasing the inner diameter of stator core 20, distance D1 becomes shorter, reducing the space required to arrange coil 25. As a result, it becomes necessary to reduce the wire diameter of coil 25, and copper loss increases due to an increase in resistance.

[0061] By satisfying the relationship D1>D2 between the distances D1 and D2, it is possible to ensure a sufficient space for arranging the coil 25. That is, it is possible to improve the efficiency of magnetic flux intake by the magnetic flux intake member 31 while suppressing an increase in copper loss.

[0062] This can also be expressed as the relationship between the cross-sectional areas E1 and E2 in a plane perpendicular to the axial direction.

[0063] In a plane perpendicular to the axial direction, the cross-sectional area of ​​the portion of the coil winding portion 22 between the lines G1 and G2 is defined as the cross-sectional area E1. The cross-sectional area E1 is the cross-sectional area of ​​the portion surrounded by the lines G1 and G2 and the side end portions 22e on both circumferential sides of the coil winding portion 22. The larger the cross-sectional area E1, the more space is available for arranging the coil 25.

[0064] In a plane perpendicular to the axial direction, the cross-sectional area of ​​the portion of the tooth tip 23 closer to the rotor 10 than the straight line G2 is defined as the cross-sectional area E2. The cross-sectional area E2 is the cross-sectional area of ​​the portion surrounded by the opposing surface 23a, back surface 23b, side end portions 23e on both circumferential sides of the tooth tip 23, and the straight line G2. The larger the cross-sectional area E2, the greater the amount of magnetic flux taken in by the magnetic flux take-in member 31 to the tooth tip 23.

[0065] The cross-sectional areas E1 and E2 satisfy E1>E2, which ensures a sufficient space for arranging the coil 25. That is, the efficiency of magnetic flux intake by the magnetic flux intake member 31 can be improved while suppressing an increase in copper loss.

[0066] 4, when magnetic flux take-in members 31 are provided on both axial sides of the tooth tip 23, the sum of the area S1a of the opposing surface 31a of one magnetic flux take-in member 31 and the area S1b of the opposing surface 31a of the other magnetic flux take-in member 31, that is, area S1 (= S1a + S1b), is larger than the area S2 of the opposing surface 23a of the tooth tip 23. In other words, S1 > S2. This allows more magnetic flux from the rotor 10 to be taken in by the magnetic flux take-in members 31.

[0067] Furthermore, the sum H1 (= H1a + H1b) of the axial length H1a of the opposing surface 31a of one magnetic flux take-in member 31 and the axial length H1b of the opposing surface 31a of the other magnetic flux take-in member 31 is longer than the axial length H2 of the opposing surface 23a of the tooth tip 23. In other words, H1 > H2 holds. This allows more magnetic flux from the rotor 10 to be taken in by the magnetic flux take-in member 31.

[0068] Furthermore, the circumferential width W1 of the opposing surface 31a of the magnetic flux intake member 31 is less than the circumferential width W2 of the opposing surface 23a of the tooth tip 23. In other words, W1 < W2 holds. This prevents contact between circumferentially adjacent tooth tips 23, thereby suppressing magnetic flux leakage between them.

[0069] <Configuration of Magnetic Flux Take-in Member> Figure 10 is a cross-sectional view showing an example of the configuration of the magnetic flux take-in member 31 together with surrounding components. The symbol Rin indicates the radially inner side, and Rout indicates the radially outer side. As shown in Figure 10, the magnetic flux take-in member 31 is supported on the tooth tip portion 23 and is guided from the radially outer side by the flange portion 43 of the insulating portion 40.

[0070] The magnetic flux intake member 31 is formed by stacking a plurality of steel plates 102. The steel plates 102 are, for example, electromagnetic steel plates. In the example shown in Fig. 10, the stacking direction of the steel plates 102 is the axial direction, similar to the stacking direction of the steel plates 101 of the stator core 20.

[0071] Since the volume of the magnetic flux intake member 31 is smaller than that of the coil winding portion 22 and the tooth tip portion 23, the magnetic flux density is likely to increase due to the inflow of magnetic flux from the rotor 10. Steel plates such as electromagnetic steel plates have small iron loss, so the increase in magnetic flux density in the magnetic flux intake member 31 is suppressed.

[0072] 11A is a cross-sectional view showing another example of the configuration of magnetic flux take-in member 31 according to embodiment 1 together with surrounding members. Symbols Rin and Rout are the same as those in FIG. 10. Magnetic flux take-in member 31 is formed by laminating a plurality of steel plates 102 in the radial direction.

[0073] 10 described above, the magnetic flux passes through the gaps in the steel plates 101 when it flows in the axial direction toward the tooth tips 23. In contrast, in the magnetic flux take-in member 31 shown in FIG. 11(A), the magnetic flux does not pass through the gaps in the steel plates 101 when it flows in the axial direction toward the tooth tips 23, and therefore the magnetic flux can be taken in to the stator core 20 more efficiently.

[0074] 11(B) and 11(C) are a perspective view and a schematic diagram showing a configuration for integrating the steel plates 102 that make up magnetic flux intake member 31 of Fig. 11(A). As shown in Fig. 11(B) and 11(C), magnetic flux intake member 31 is formed by integrating a stack of steel plates 102 by crimping 31f and then bending the stack.

[0075] The crimps 31f are V-shaped crimps that are long in the axial direction as shown in Fig. 11(B) and have a depth in the radial direction as shown in Fig. 11(C). The positions and number of the crimps 31f are arbitrary.

[0076] 12 is a flowchart showing a method for manufacturing the electric motor 1 according to embodiment 1. In step S11, the stator core 20 is assembled by stacking the steel plates 101 in the axial direction and fixing them by caulking or the like.

[0077] In step S12 , the magnetic flux intake member 31 is attached to at least one end face 23 c of each tooth tip 23 of the stator core 20 .

[0078] In step S13, insulating portion 40 is attached to stator core 20. Insulating portion 40 may be formed by integrally molding resin together with stator core 20 and magnetic flux intake member 31, or may be molded in advance and attached to stator core 20.

[0079] By attaching the insulating part 40 to the stator core 20, the magnetic flux take-in member 31 is held in a state in which it is sandwiched from both sides in the circumferential direction by the flange parts 43 of the insulating part 40 (see FIG. 5B). Steps S12 and S13 correspond to the process of fixing the magnetic flux take-in member 31.

[0080] In step S14, the coil 25 is wound around the coil winding portion 22 with the insulating portion 40 interposed therebetween.

[0081] In step S15, the stator core 20, magnetic flux take-in members 31, insulating parts 40, and coils 25 are molded. Specifically, the stator core 20, magnetic flux take-in members 31, insulating parts 40, and coils 25 are placed in a mold, and molding resin is poured into them. This forms a molding resin part 50 that covers the stator core 20, magnetic flux take-in members 31, insulating parts 40, and coils 25, and the stator 2 is completed.

[0082] In step S16, the rotor 10 is fixed to the rotating shaft 15, and the bearings 16 and 17 are attached to the rotor 10. The rotor 10 is then inserted into the stator core 20 through the opening 50a of the molded resin portion 50.

[0083] In step S17, brackets 51 and 52 for fixing bearings 16 and 17 are attached to openings 50a and 50b of molded resin portion 50. In this way, electric motor 1 is completed.

[0084] Step S15 is not necessary if the electric motor 1 does not have the molded resin part 50. Also, instead of the molded resin part 50, the electric motor 1 may be attached to, for example, a metal shell.

[0085] Fig. 13 is a cross-sectional view showing another configuration example of the electric motor 1 according to embodiment 1. In the configuration example shown in Fig. 13, magnetic flux intake members 31 are provided on only one side of the stator core 20 in the axial direction.

[0086] Specifically, the rotor 10 protrudes more from the stator core 20 on the load side, and the magnetic flux take-in member 31 is provided on the load side of the stator core 20. In this case as well, more magnetic flux can be taken in from the magnetic flux take-in member 31 to the stator core 20.

[0087] 14 is a perspective view showing a part of the stator core 20 and the magnetic flux take-in member 31 according to the first embodiment. The magnetic flux take-in member 31 is attached to one end face 23c of the tooth tip portion 23 of the stator core 20.

[0088] An area S1 of the facing surface 31a of the magnetic flux take-in member 31 that faces the rotor 10 is larger than an area S2 of the facing surface 23a of the tooth tip 23 that faces the rotor 10. Furthermore, an axial length H1 of the facing surface 31a of the magnetic flux take-in member 31 is larger than an axial length H2 of the facing surface 23a of the tooth tip 23. This allows more magnetic flux to be taken in from the magnetic flux take-in member 31 to the stator core 20.

[0089] Effect of First Embodiment As described above, in electric motor 1 according to the first embodiment, stator core 20 has an annular yoke 21, a coil winding portion 22 that extends from yoke 21 toward rotor 10 and is wound with coil 25, and tooth tips 23 that are provided at the tips of coil winding portion 22 and face rotor 10. Magnetic flux take-in members 31 are provided on at least one axial end of tooth tips 23 of stator core 20. A cross-sectional area A of magnetic flux take-in member 31 in a plane perpendicular to rotation axis Ax, a cross-sectional area B of coil winding portion 22 in a plane perpendicular to the radial direction, and a cross-sectional area C of yoke 21 in a plane perpendicular to the circumferential direction satisfy A<B and A<C.

[0090] By providing the magnetic flux intake member 31, it is possible to take in more of the magnetic flux from the rotor 10 into the stator core 20. Furthermore, because the cross-sectional areas A, B, and C satisfy A<B and A<C, it is possible to alleviate the concentration of magnetic flux in the coil winding portion 22 and the yoke 21 and suppress magnetic saturation. This improves the efficiency of magnetic flux utilization and improves the output of the electric motor 1.

[0091] Furthermore, if a line G1 is defined as a line that passes through the end 25a of the coil 25 on the yoke 21 side and is perpendicular to the center line T of the coil winding portion 22, and a line G2 is defined as a line that passes through the end 25b of the coil 25 on the rotor 10 side and is perpendicular to the center line T, then the distance D1 between the lines G1 and G2 and the distance D2 between the line G2 and the tooth tip center F satisfy D1 > D2. Therefore, a sufficient arrangement space for the coil 25 can be secured. This makes it possible to improve the magnetic flux intake efficiency of the magnetic flux intake member 31 while suppressing an increase in copper loss.

[0092] Furthermore, in a plane perpendicular to the axial direction, the cross-sectional area E1 of the portion of the coil winding portion 22 between the lines G1 and G2 and the cross-sectional area E2 of the portion of the tooth tip 23 on the rotor 10 side of the line G2 satisfy the relationship E1 > E2. This makes it possible to ensure sufficient space for arranging the coil 25. This makes it possible to improve the efficiency of magnetic flux intake by the magnetic flux intake member 31 while suppressing an increase in copper loss.

[0093] Furthermore, since the area S1, which is the sum of the areas of the opposing surfaces 31a of the magnetic flux intake member 31 facing the rotor 10, is larger than the area S2 of the opposing surfaces 23a of the tooth tip portion 23 facing the rotor 10, more magnetic flux can be taken in from the magnetic flux intake member 31.

[0094] Furthermore, since the length H1, which is the sum of the axial lengths of the opposing surfaces 31a of the magnetic flux intake member 31, is greater than the axial length H2 of the opposing surfaces 23a of the tooth tip portion 23, more magnetic flux can be taken in from the magnetic flux intake member 31.

[0095] Furthermore, since the circumferential width W1 of the magnetic flux intake member 31 is less than the circumferential width W2 of the tooth tip portion 23, contact between adjacent tooth tip portions 23 in the circumferential direction can be avoided, and magnetic flux leakage between them can be suppressed.

[0096] Furthermore, since the magnetic flux take-in member 31 is formed of a laminate of steel plates 102, an increase in magnetic flux density in the magnetic flux take-in member 31 is suppressed.

[0097] In particular, since the stacking direction of the steel plates 102 of the magnetic flux intake member 31 is radial, the magnetic flux within the magnetic flux intake member 31 flows into the stator core 20 without passing through the gaps between the steel plates 102, thereby improving the efficiency of magnetic flux intake into the stator core 20.

[0098] Furthermore, since the laminate of steel plates 102 of magnetic flux intake member 31 is fixed by caulking, the curved laminate can be reliably integrated.

[0099] Furthermore, since the magnetic flux take-in member 31 is held by the insulating portion 40 serving as the first insulating member, the magnetic flux take-in member 31 can be held so as not to move due to the magnetic force acting between the magnetic flux take-in member 31 and the rotor 10 .

[0100] Furthermore, since the magnetic flux take-in member 31 and the stator core 20 are held by the insulating portion 40 serving as the second insulating member, the magnetic flux take-in member 31 can be held together with the stator core 20 more firmly.

[0101] 15 is a plan view showing the coil winding portions 22, tooth tips 23, and magnetic flux take-in members 30 of a stator 2A of an electric motor 1A according to a second embodiment, and the rotor 10. The electric motor 1A according to the second embodiment differs from the electric motor 1 according to the first embodiment in that adjacent magnetic flux take-in members 31 in the circumferential direction are connected by connecting portions 32.

[0102] The magnetic flux take-in members 31 and the connecting portions 32 are formed as a single unit. The magnetic flux take-in members 31 and the connecting portions 32 are collectively referred to as the magnetic flux take-in body 30. If the number of magnetic flux take-in members 31 is M (M is an integer of 2 or greater), then in Figure 15 M magnetic flux take-in members 31 are connected by connecting portions 32 to form the integrated magnetic flux take-in body 30. However, it is sufficient that at least two of the M magnetic flux take-in members 31 are connected by connecting portions 32.

[0103] The connecting portion 32 extends radially outward beyond the magnetic flux take-in member 31. The opposing surface 31a of the magnetic flux take-in member 31 is exposed from the molded resin portion 50 (FIG. 16), whereas the connecting portion 32 is covered by the molded resin portion 50.

[0104] The magnetic flux take-in member 31 and the connecting portion 32 have a curved shape such that the side facing the rotor 10 is concave, but the radius of curvature of the connecting portion 32 is smaller than the radius of curvature of the magnetic flux take-in member 31 .

[0105] Fig. 16 is a view of the stator 2A as seen from the rotor 10 side. In Fig. 16, the magnetic flux take-in body 30 is provided at one axial end of the stator core 20. However, the magnetic flux take-in body 30 may be provided at both axial ends of the stator core 20.

[0106] The connecting portion 32 is connected to the upper end of the magnetic flux intake member 31, i.e., the end axially away from the stator core 20. The connecting portion 32 has an opposing surface 32a that faces the outer peripheral surface 10a of the rotor 10.

[0107] 17A is a schematic diagram illustrating the area J1 of the facing surface 31a of the magnetic flux take-in member 31. The facing surface 31a of the magnetic flux take-in member 31 has a length T1 in the axial direction and a width U1 in the circumferential direction. The area J1 of the facing surface 31a of the magnetic flux take-in member 31 is T1 x U1.

[0108] 17(B) is a schematic diagram for explaining the area J2 of the opposing surface 32a of the connecting portion 32. The opposing surface 32a of the connecting portion 32 has a length T2 in the axial direction and a width U2 in the circumferential direction. The area J2 of the opposing surface 32a of the connecting portion 32 is T2 × U2.

[0109] The area J1 of the facing surface 31a of the magnetic flux take-in member 31 is larger than the area J2 of the facing surface 32a of the connecting portion 32. In other words, A1 > A2 holds. Therefore, the magnetic flux flowing from the rotor 10 to the facing surface 32a of the connecting portion 32 is small, and the magnetic flux flowing to the facing surface 31a of the magnetic flux take-in member 31 is large.

[0110] 18A is a schematic diagram illustrating the cross-sectional area K1 of the magnetic flux take-up member 31. The cross-sectional area K1 of the magnetic flux take-up member 31 is the cross-sectional area in a plane perpendicular to the circumferential direction. The magnetic flux take-up member 31 has a length T1 in the axial direction and a width V1 in the radial direction. The cross-sectional area K1 of the magnetic flux take-up member 31 is T1 x V1.

[0111] 18(B) is a schematic diagram illustrating the cross-sectional area K2 of the connecting portion 32. The cross-sectional area K2 of the connecting portion 32 is the cross-sectional area in a plane perpendicular to the circumferential direction. The connecting portion 32 has a length T2 in the axial direction and a width V2 in the radial direction. The cross-sectional area K2 of the connecting portion 32 is T2 × V2.

[0112] The cross-sectional area K2 of the connecting portion 32 is smaller than the cross-sectional area K1 of the magnetic flux intake member 31. In other words, K1 > K2 holds true. Therefore, magnetic flux does not easily flow through the connecting portion 32, and thus leakage magnetic flux between adjacent magnetic flux intake members 31 is reduced.

[0113] Figure 19(A) is a cross-sectional view of the stator 2A and the rotor 10 taken along line 19A-19A in Figure 16. Figure 19(B) is a cross-sectional view of the stator 2A and the rotor 10 taken along line 19B-19B in Figure 16. In Figures 19(A) and 19(B), the radially inner side is indicated by an arrow Rin, and the radially outer side is indicated by an arrow Rout.

[0114] 19A, the opposing surface 31a of the magnetic flux take-in member 31 is exposed from the molded resin portion 50, similar to the opposing surface 23a of the tooth tip portion 23. The distance from the rotor 10 to the opposing surface 31a of the magnetic flux take-in member 31 is C1.

[0115] 19B, the opposing surface 32a of the connecting portion 32 is covered with the molded resin portion 50. The distance from the rotor 10 to the opposing surface 32a of the connecting portion 32 is C2.

[0116] Distances C1 and C2 satisfy C1 < C2. That is, the distance from rotor 10 to connecting portion 32 is longer than the distance from rotor 10 to magnetic flux intake member 31. This makes it difficult for magnetic flux from rotor 10 to reach connecting portion 32. In addition, the rotor 10 side of connecting portion 32 is covered with molded resin portion 50, which prevents deformation or peeling of connecting portion 32 due to the magnetic attraction force with rotor 10.

[0117] As described in the first embodiment, both the magnetic flux take-in member 31 and the connecting portion 32 are formed of laminated steel plates 102. In the configuration example shown in Figures 19(A) and 19(B), the lamination direction of the steel plates 102 in the magnetic flux take-in member 31 and the connecting portion 32 is the axial direction, which is the same as the lamination direction of the steel plates 101 in the stator core 20.

[0118] Figures 20(A) and (B) are cross-sectional views for explaining another configuration example of the magnetic flux intake member 31, and correspond to the cross-sectional views along the line 19A-19A shown in Figure 16 and the cross-sectional views along the line 19B-19B shown in Figure 16.

[0119] Both the magnetic flux take-in member 31 and the connecting portion 32 are configured by stacking steel plates 102. However, the stacking direction of the steel plates 102 in the magnetic flux take-in member 31 and the connecting portion 32 is the radial direction.

[0120] In this case, since the lamination direction of the steel sheets 102 is the radial direction, the magnetic flux heading toward the tooth tip 23 does not pass through the lamination gaps of the steel sheets 101. Therefore, the magnetic flux can be taken into the stator core 20 more efficiently.

[0121] Furthermore, by making the number of steel plates 102 forming the connecting portion 32 smaller than the number of steel plates 102 forming the magnetic flux intake member 31, the radial width V2 of the connecting portion 32 can be made narrower than the radial width V1 of the magnetic flux intake member 31. This will be described later (see FIG. 22 ).

[0122] The manufacturing method of the electric motor 1A of the second embodiment is the same as that described in the first embodiment with reference to Fig. 12. In step S12 (Fig. 12), the M magnetic flux intake members 31 can be handled as a single unit, which simplifies the manufacturing process.

[0123] In this example, all of the M magnetic flux take-in members 31 are connected by the connecting portions 32, but it is sufficient if at least two magnetic flux take-in members 31 are connected by the connecting portions 32. In this case as well, the two magnetic flux take-in members 31 can be handled as a single component, which simplifies the manufacturing process of the electric motor 1 and improves productivity.

[0124] Except for the points mentioned above, the electric motor 1A of the second embodiment is configured similarly to the electric motor 1 of the first embodiment.

[0125] As described above, in the electric motor 1A of the second embodiment, at least two of the M magnetic flux take-in members 31 are connected by the connecting portions 32, which makes it possible to more reliably hold the magnetic flux take-in members 31. Furthermore, in the manufacturing process of the electric motor 1A, the at least two magnetic flux take-in members 31 can be handled as a single unit, which simplifies the manufacturing process.

[0126] Furthermore, since the distance C2 between the connecting portion 32 and the rotor 10 is longer than the distance C1 between the magnetic flux intake member 31 and the rotor 10 (C1<C2), it is possible to reduce the magnetic flux flowing from the rotor 10 into the connecting portion 32. Furthermore, since the rotor 10 side of the connecting portion 32 is covered with the molded resin portion 50, it is possible to prevent deformation of the connecting portion 32 due to the magnetic attraction force with the rotor 10.

[0127] Furthermore, since the area J2 of the opposing surface 32a of the connecting portion 32 is smaller than the area J1 of the opposing surface 31a of the magnetic flux intake member 31 (J1 > J2), the magnetic flux flowing from the rotor 10 into the connecting portion 32 can be reduced, and the magnetic flux flowing into the magnetic flux intake member 31 can be increased.

[0128] Furthermore, since the cross-sectional area K2 of the connecting portion 32 is smaller than the cross-sectional area K1 of the magnetic flux intake member 31 (K1>K2), magnetic flux leakage between the magnetic flux intake members 31 via the connecting portion 32 can be suppressed.

[0129] 21 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux take-in member 30 of stator 2B of electric motor 1B according to a modification of embodiment 2, and rotor 10. Electric motor 1B according to embodiment 2 differs from electric motor 1A according to embodiment 2 in that the radial width V2 of connecting portion 32B is narrower than the radial width V1 of magnetic flux take-in member 31.

[0130] Since the radial width V2 of the connecting portion 32B is narrower than the radial width V1 of the magnetic flux intake member 31, the cross-sectional area of ​​the connecting portion 32B is sufficiently smaller than the cross-sectional area of ​​the magnetic flux intake member 31, thereby enhancing the effect of suppressing magnetic flux leakage between adjacent magnetic flux intake members 31.

[0131] The magnetic flux intake body 30B consisting of the magnetic flux intake member 31 and the connecting portion 32B is preferably formed of a laminate in which steel plates 102 are stacked in the radial direction, as described in embodiment 2 with reference to Figures 20(A) and (B).

[0132] Figure 22 is a cross-sectional view showing stator 2B and rotor 10, and corresponds to the cross-sectional view taken along line 19B-19B in Figure 16. As shown in Figure 22, the number of steel plates 102 forming connecting portion 32B is less than the number of steel plates 102 (Figure 20(A)) forming magnetic flux take-up member 31. This allows radial width V2 of connecting portion 32B to be narrower than radial width V1 of magnetic flux take-up member 31.

[0133] In this case, it is desirable that the connecting portion 32B does not have any steel plates 102 (shown by dashed lines in FIG. 22 ) that are the same as those in the magnetic flux intake member 31, but that are on the side away from the rotor 10, i.e., the radially outer steel plates 102. In other words, it is desirable that the steel plates that form the connecting portion 32B are connected to the steel plates that form the magnetic flux intake member 31 and that are located on the radially inner side.

[0134] In this way, the connecting portion 32B connects the radially inner ends of adjacent magnetic flux intake members 31, thereby preventing displacement of the magnetic flux intake members 31 due to the magnetic attraction force with the rotor 10.

[0135] The magnetic flux taker 30B of the modified example is not limited to the steel plates 102 stacked in the radial direction, but may be the steel plates 102 stacked in the axial direction as described with reference to Figures 19(A) and 19(B) in embodiment 2. Furthermore, the magnetic flux taker 30B may be made of a magnetic material other than steel plates.

[0136] Except for the above-mentioned points, the electric motor 1B of the modified example is configured similarly to the electric motor 1A of the second embodiment.

[0137] As described above, in electric motor 1B according to the modified example of embodiment 2, radial width V2 of connecting portion 32B is narrower than radial width V1 of magnetic flux take-up member 31, thereby suppressing magnetic flux leakage between adjacent magnetic flux take-up members 31. Furthermore, connecting portion 32B connects the radially inner ends of adjacent magnetic flux take-up members 31, thereby preventing displacement of magnetic flux take-up members 31 due to magnetic attraction.

[0138] Embodiment 3. Figure 23 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux taker 30C of a stator 2C of an electric motor 1C according to Embodiment 3, together with the rotor 10. The electric motor 1C according to Embodiment 3 differs from the magnetic flux taker 30B (Figure 21) of the stator 2B according to the modified example of Embodiment 2 in that the connecting portion 32C of the magnetic flux taker 30C is cut off.

[0139] 23 , in the third embodiment, the connecting portion 32C is cut at its circumferential center. By cutting the connecting portion 32C, two protrusions 38 are formed. The two protrusions 38 are collectively referred to as a protrusion pair 37.

[0140] That is, in the magnetic flux take-in body 30C, a pair of protrusions 37 is formed between two adjacent magnetic flux take-in members 31. The pair of protrusions 37 has two protrusions 38 that are close to each other in the circumferential direction and extend radially outward.

[0141] 24 is a flowchart showing a manufacturing method of electric motor 1C of embodiment 3. In step S11, steel plates are stacked in the axial direction and fixed by caulking or the like to assemble stator core 20 (FIG. 20A).

[0142] In step S12, magnetic flux taker 30C is attached to the end surface of stator core 20. At this stage, magnetic flux taker 30C has the same shape as magnetic flux taker 30B (FIG. 21) of the modified example of Embodiment 2. That is, N magnetic flux taker members 31 are connected by connecting portions 32C.

[0143] In step S13, the insulating portion 40 is attached to the stator core 20. By attaching the insulating portion 40 to the stator core 20, the magnetic flux intake member 31 of the magnetic flux intake body 30C is held in a state where it is sandwiched between the insulating portions 40 from both sides in the circumferential direction.

[0144] In the next step S20, the connecting portion 32C of the magnetic flux taker 30C is cut with a cutter or the like. By cutting the connecting portion 32C, a pair of projections 37 shown in FIG.

[0145] In subsequent steps S14 to S17, similar to steps S14 to S17 in the first embodiment, coil 25 is wound around insulating portion 40, stator 2C is formed by molding, rotor 10 is inserted into stator 2C, and brackets 51 and 52 are attached to molded resin portion 50. This completes electric motor 1C of the third embodiment.

[0146] In step S12, the N magnetic flux take-in members 31 are connected by the connecting portions 32C, so that the magnetic flux take-in body 30C can be handled as a single component. Furthermore, in step S20, the connecting portions 32C are cut, so that magnetic flux leakage between adjacent magnetic flux take-in members 31 can be effectively suppressed. Furthermore, because the connecting portions 32C (i.e., the protrusion pairs 37) are covered together with the magnetic flux take-in members 31 by the molded resin portion 50, the magnetic flux take-in members 31 and the connecting portions 32C can be held in place more reliably.

[0147] Here, we have described an example in which N magnetic flux intake members 31 are connected by connecting portions 32C, but it is sufficient if at least two magnetic flux intake members 31 are connected by connecting portions 32C, and the connecting portions 32C are cut off after attachment to the stator core 20.

[0148] In magnetic flux taker 30C shown in Fig. 23, similar to magnetic flux taker 30B (Fig. 21) of the modified example of embodiment 2, radial width V2 of connecting portion 32C is formed to be narrower than radial width V1 of magnetic flux taker member 31. However, the radial widths of magnetic flux taker member 31 and connecting portion 32C may be the same.

[0149] Furthermore, the magnetic flux intake body 30C may be made of steel plates stacked in the axial direction, or may be made of steel plates stacked in the radial direction, or may be made of a magnetic material other than steel plates.

[0150] Except for the points mentioned above, the electric motor 1C of the third embodiment is configured similarly to the electric motor 1B of the modified example of the second embodiment.

[0151] As described above, in electric motor 1C of embodiment 3, magnetic flux taker 30C having magnetic flux taker member 31 and connecting portion 32C is attached to stator core 20, and then connecting portion 32C is cut. This simplifies handling of magnetic flux taker 30C when attaching it to stator core 20, and furthermore, cutting connecting portion 32C effectively suppresses magnetic flux leakage.

[0152] 25 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux taker 30D of a stator 2D of an electric motor 1D according to a fourth embodiment, and the rotor 10. In the electric motor 1D according to the fourth embodiment, the configuration of the magnetic flux taker 30D differs from that of the magnetic flux taker 30 according to the second embodiment.

[0153] 25 , a magnetic flux taker 30D according to the fourth embodiment has M (M is an integer of 2 or greater) magnetic flux take-up members 31 and M−1 connecting portions 32D. Of the M magnetic flux take-up members 31, no connecting portion 32D is formed between two magnetic flux take-up members 31 indicated by the symbol End. A non-connecting portion 39, which is a gap, is formed between the two magnetic flux take-up members 31.

[0154] In other words, the magnetic flux intake body 30D is formed in an annular shape so as to extend in the circumferential direction around the rotation axis Ax and so that both ends thereof face each other with the non-connecting portion 39 therebetween.

[0155] Fig. 26 is a plan view showing steel plates 102 forming magnetic flux absorber 30D. Magnetic flux absorber 30D is formed by laminating steel plates 103 in the radial direction. In Fig. 26, arrow Z indicates the direction of rotation axis Ax.

[0156] N magnetic flux capture members 31 and N-1 connecting portions 32D are arranged in a strip shape on the steel plate 102. The magnetic flux capture members 31 indicated by the symbol End in Fig. 26 are located at both ends of the steel plate 102 in the arrangement direction.

[0157] The magnetic flux take-in body 30D shown in Fig. 25 is formed by stacking the steel plates 102 shown in Fig. 26 and bending them into a ring shape so that the stacking direction is the radial direction. As described above, a non-connecting portion 39 is formed between the two magnetic flux take-in members 31 located at both ends.

[0158] 22, by removing some of the steel plates 102 forming the connecting portion 32D from the radially outer side, the radial width of the connecting portion 32D can be made narrower than the radial width of the magnetic flux take-up member 31. Note that the radial widths of the magnetic flux take-up member 31 and the connecting portion 32D may be the same.

[0159] In the fourth embodiment, M magnetic flux intake members 31 are connected by M-1 connecting portions 32D, and therefore can be handled as a single component. Furthermore, magnetic flux intake body 30D is formed by bending a laminated body of strip-shaped steel plates 102, as shown in FIG. 26, into a ring shape. This simplifies the manufacturing process of electric motor 1.

[0160] Except for the points mentioned above, the electric motor 1D of the fourth embodiment is configured similarly to the electric motor 1A of the second embodiment.

[0161] As described above, in electric motor 1D of embodiment 4, M magnetic flux taker members 31 and M-1 connecting portions 32D constitute magnetic flux taker 30D, which extends in the circumferential direction about rotation axis Ax, with both ends facing each other across non-connecting portions 39. Therefore, magnetic flux taker 30D can be formed by curving a laminate formed by stacking strip-shaped steel plates 102, thereby simplifying the manufacturing process.

[0162] Fifth Embodiment Fig. 27 is a cross-sectional view showing an electric motor 1E according to a fifth embodiment. In the electric motor 1E according to the fifth embodiment, an impeller 81 is fixed to the tip 15a of the rotating shaft 15. A hub may be provided between the impeller 81 and the rotating shaft 15. The impeller 81 and the electric motor 1E constitute an outdoor fan 80 as a blower.

[0163] In addition, in the electric motor 1 (Figure 1) of embodiment 1, an opening 50b was formed on the anti-load side of the molded resin part 50, but in the electric motor 1E of embodiment 5, a bottom 55 is formed on the anti-load side of the molded resin part 50.

[0164] A bearing holder 56 that holds the bearing 17 is formed on the bottom 55 of the molded resin part 50. A circuit board 57 is also held on the bottom 55 of the molded resin part 50. A drive circuit and the like for rotating the electric motor 1E are mounted on the circuit board 57. The circuit board 57 is connected to the coil 25 via a terminal 47 provided on the insulating part 40.

[0165] The outer diameter of the impeller 81 is larger than the outer diameter of the stator core 20. When the outer diameter of the impeller 81 attached to the rotating shaft 15 is large, the inertia during rotation is large, and a force acts on the rotating shaft 15 in the torsional direction about the rotation axis Ax, which causes an increase in noise. In addition, the deflection of the rotating shaft 15 due to the weight of the impeller 81 also causes an increase in noise.

[0166] Furthermore, when a current flows through the coil 25, magnetic attractive and repulsive forces act between the generated electric field and the rotor 10. When the vibration components caused by these magnetic forces resonate with the vibration components caused by torsion and bending of the rotating shaft 15, noise becomes particularly loud.

[0167] In the electric motor 1E, the stator core 20 is held in a state where it is covered with the molded resin part 50, and the bearings 16 and 17 that support the rotating shaft 15 are also held by the molded resin part 50 via the bracket 51. Therefore, it is possible to suppress an increase in noise of the electric motor 1E due to resonance of the vibration components described above.

[0168] In the electric motor 1E of the fifth embodiment, the magnetic flux take-in members 31 are provided on both axial ends of the stator core 20, so that a large amount of magnetic flux can be taken in by the stator core 20 from the rotor 10 via the magnetic flux take-in members 31. Note that the magnetic flux take-in members 31 may be provided on only one axial end of the stator core 20.

[0169] Except for the points mentioned above, the electric motor 1E of the fifth embodiment is configured similarly to the electric motor 1 of the first embodiment.

[0170] In electric motor 1E of embodiment 5, impeller 81 is attached to rotating shaft 15, and the outer diameter of impeller 81 is larger than the outer diameter of stator core 20. Although torsional and bending forces are applied to rotating shaft 15, stator core 20 is held in a state covered with molded resin portion 50, and therefore, an increase in noise from electric motor 1 can be suppressed.

[0171] In the first to fifth embodiments and the modified examples, an inner rotor type electric motor has been described in which the stator 2 surrounds the rotor 10. However, the configurations described in the first to fifth embodiments and the modified examples can also be applied to an outer rotor type electric motor in which the rotor 10 surrounds the stator 2.

[0172] In addition, in the second to fifth embodiments and the modified examples, the magnetic flux take-in member 31 and the connecting portion 32 are integrally formed from the same material. However, the magnetic flux take-in member 31 and the connecting portion 32 may be formed from different materials.

[0173] <Air Conditioning Apparatus> Next, an air conditioner to which the electric motors of the above-described embodiments and modifications can be applied will be described. Fig. 28(A) is a diagram showing an air conditioner 7 to which the electric motor 1 of embodiment 1 is applied. The air conditioner 7 includes an outdoor unit 8 and an indoor unit 9. The outdoor unit 8 and the indoor unit 9 are connected by a refrigerant pipe 71.

[0174] The outdoor unit 8 includes an outdoor fan 80 as a blower, a condenser 83, a compressor 84, and a housing 82 that houses these components. The outdoor fan 80 includes an impeller 81 and an electric motor 1 that drives the impeller 81. The electric motor 1 has the configuration described in the first embodiment.

[0175] The indoor unit 9 includes an indoor fan 90 as a blower, an evaporator 93, and a housing 92 that houses these components. The indoor fan 90 has an impeller 91 and an electric motor 95 that drives the impeller 91.

[0176] 28(B) is a cross-sectional view of the outdoor unit 8. The electric motor 1 is supported by a motor support 85 arranged inside a housing 82 of the outdoor unit 8. An impeller 81 is attached to the rotating shaft 15 of the electric motor 1 via a hub 86.

[0177] In the outdoor blower 80, an impeller 81 is rotated by the electric motor 1. During cooling operation of the air conditioner 7, the heat released when the refrigerant compressed by the compressor 84 is condensed in the condenser 83 is released to the outside by the air blown by the outdoor blower 80.

[0178] In the indoor fan 90 (FIG. 28A), an impeller 91 is rotated by an electric motor 95. During cooling operation of the air conditioner 7, the air from which heat has been removed when the refrigerant evaporates in the evaporator 93 is blown into the room by the indoor fan 90.

[0179] Since the electric motor 1 of the first embodiment has high electric motor efficiency, it is possible to improve the operating efficiency of the outdoor blower 80, and thereby to improve the operating efficiency of the air conditioner 7.

[0180] Here, the electric motor 1 of the first embodiment is used as the drive source for the outdoor blower 80, but the electric motor of any of the second to fifth embodiments or the modified examples may also be used.

[0181] Furthermore, the electric motors of the first to fifth embodiments and the modified examples may be used as the electric motor 95 of the indoor blower 90, or may be used as the electric motors of both the outdoor blower 80 and the indoor blower 90.

[0182] Although the preferred embodiments have been specifically described above, the present disclosure is not limited to the above-described embodiments, and various improvements and modifications can be made.

[0183] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D, 1E Electric motor, 2, 2A, 2B, 2C, 2D Stator, 7 Air conditioner, 8 Outdoor unit, 9 Indoor unit, 10 Rotor, 11, 12 Permanent magnet pole, 13 Rotor unit, 15 Rotating shaft, 20 Stator core, 21 Yoke, 21e Boundary portion, 22 Coil winding portion, 23 Tooth tip portion, 24 Slot, 25 Coil, 30, 30B, 30C, 30D Magnetic flux intake body, 31 Magnetic flux intake member, 32, 32B, 32C, 32D Connecting portion, 37 Protrusion pair, 38 Protrusion, 39 Non-connecting portion, 40 Insulating portion (first resin portion), 41 Wall portion, 42 Body portion, 43 Flange portion, 50 molded resin portion (outer casing member, second resin portion), 80 outdoor blower, 81 impeller, 90 indoor blower, 91 impeller, 95 electric motor, 101, 102, 103 steel plate, A cross-sectional area of ​​magnetic flux intake member, B cross-sectional area of ​​coil winding portion, C cross-sectional area of ​​yoke.

Claims

1. A stator having a rotor rotatable about a rotation axis, a stator core facing the rotor in a radial direction centered on the rotation axis, and a coil wound around the stator core, wherein the rotor protrudes at least on one side in the axial direction of the rotation axis from the stator core, the stator core has a yoke extending in a circumferential direction centered on the rotation axis, a coil winding portion extending from the yoke toward the rotor around which the coil is wound, and a tooth tip portion provided at a tip of the coil winding portion and facing the rotor, the stator has a magnetic flux capturing member at at least one end in the axial direction of the tooth tip portion, and a cross-sectional area A of the magnetic flux capturing member in a plane orthogonal to the rotation axis, a cross-sectional area B of the coil winding portion in a plane orthogonal to the radial direction, and a cross-sectional area C of the yoke in a plane orthogonal to the circumferential direction satisfy A < B and A < C. An electric motor.

2. In the coil winding portion, when a distance between a first position where an end portion of the coil on a side facing the yoke is located and a second position where an end portion of the coil on a side facing the rotor is located is D1, and a distance between the second position of the coil winding portion and a circumferential center of a surface of the tooth tip portion facing the rotor is D2, D1 > D2 holds. The electric motor according to claim 1.

3. In the coil winding portion, when a cross-sectional area in a plane orthogonal to the rotation axis of a portion between a first position where an end portion of the coil on a side facing the yoke is located and a second position where an end portion of the coil on a side facing the rotor is located is E1, and a cross-sectional area in a plane orthogonal to the rotation axis of a portion between the second position of the coil winding portion and a surface of the tooth tip portion facing the rotor is E2, E1 > E2 holds. The electric motor according to claim 1 or 2.

4. An area S1 which is a sum of areas of opposing surfaces of the magnetic flux capturing member facing the rotor and an area S2 of opposing surfaces of the tooth tip portion facing the rotor satisfy S1 > S2. The electric motor according to any one of claims 1 to 3.

5. A length H1 which is a sum of lengths in the direction of the rotation axis of opposing surfaces of the magnetic flux capturing member facing the rotor and a length H2 of opposing surfaces of the tooth tip portion facing the rotor in the direction of the rotation axis satisfy H1 > H2. The electric motor according to any one of claims 1 to 4.

6. The circumferential length W1 of the magnetic flux capturing member and the circumferential length W2 of the tooth tip portion satisfy W1 < W2. The electric motor according to any one of claims 1 to 5.

7. The magnetic flux capturing member is composed of a laminate of steel plates. The electric motor according to any one of claims 1 to 6.

8. The lamination direction of the steel plates is the direction of the rotation axis. The electric motor according to claim 7.

9. The lamination direction of the steel plates is the radial direction. The electric motor according to claim 7.

10. The steel plates are fixed by caulking. The electric motor according to any one of claims 7 to 9.

11. The magnetic flux capturing member has a curved shape along the outer peripheral surface of the rotor. The electric motor according to any one of claims 1 to 10.

12. The electric motor further includes a first insulating member for fixing the magnetic flux capturing member to the stator core. The electric motor according to any one of claims 1 to 10.

13. The electric motor further includes a second insulating member for holding the magnetic flux capturing member, the stator core, and the first insulating member. The electric motor according to claim 12.

14. It has a connecting portion protruding from the circumferential end of the magnetic flux capturing member, and the distance C1 from the rotor to the magnetic flux capturing member and the distance C2 from the rotor to the connecting portion satisfy C1 < C2. The electric motor according to any one of claims 1 to 13.

15. The electric motor further includes an insulating member for holding the magnetic flux capturing member and the stator core, and at least the surface on the side facing the rotor at the connecting portion is covered with the insulating member. The electric motor according to claim 14.

16. The cross-sectional area K1 in the plane orthogonal to the circumferential direction of the magnetic flux capturing member and the cross-sectional area K2 in the plane orthogonal to the circumferential direction of the connecting portion satisfy K1 > K2. The electric motor according to claim 14 or 15.

17. The area J1 of the surface of the magnetic flux capturing member facing the rotor and the area J2 of the surface of the connecting portion facing the rotor satisfy J1 > J2. The electric motor according to any one of claims 14 to 16.

18. The magnetic flux capturing member is one of M (M is an integer of 2 or more) magnetic flux capturing members arranged in the circumferential direction, and at least two of the M magnetic flux capturing members are connected by the connecting portion. The electric motor according to any one of claims 14 to 17.

19. The magnetic flux capturing body is constituted by the M magnetic flux capturing members and the M - 1 connecting portions, and the magnetic flux capturing body extends in the circumferential direction and is formed in an annular shape such that both ends thereof face each other with a non - connecting portion therebetween. The electric motor according to any one of claims 18 to 19.

20. The connecting portion is constituted by a laminate of steel plates. The electric motor according to any one of claims 14 to 19.

21. The lamination direction of the steel plates in the laminate is the radial direction, and the number of laminated steel plates in the connecting portion is smaller than the number of laminated steel plates in the magnetic flux capturing member. The electric motor according to claim 20.

22. A blower comprising the electric motor according to any one of claims 1 to 21, and an impeller attached to the rotating shaft of the electric motor.

23. The outer diameter of the impeller is larger than the outer diameter of the stator core. The blower according to claim 22.

24. An air conditioner comprising an outdoor unit and an indoor unit, wherein at least one of the outdoor unit and the indoor unit has the blower according to claim 22 or 23.

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