Electric motor, blower, and air conditioning device

Abstract

This electric motor has: a rotor that can rotate about a rotational shaft; and a stator having a stator core that faces the rotor in the radial direction centered on the rotational shaft and having coils that are wound around the stator core. The stator has a magnetic body part attached to at least one end of the stator core in the axial direction and facing the rotor. The magnetic body part is configured by a laminated body in which a plurality of electromagnetic steel sheets are laminated and is curved along the outer peripheral surface of the rotor.

Description

Electric motors, fans and air conditioners

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

[0002] The electric motor has a rotatable rotor and a stator facing the rotor. For example, Patent Document 1 proposes an electric motor in which a magnetic body is attached to the axial end face of a stator core of the stator to take in magnetic flux from the rotor.

[0003] JP 2014-147177 A (see FIG. 1)

[0004] Here, because the magnetic flux density is high on the rotor surface, the magnetic flux density inside the magnetic body is also high. The higher the magnetic flux density inside the magnetic body, the greater the loss caused by the magnetic flux flowing inside the magnetic body, i.e., iron loss, and the lower the efficiency of magnetic flux capture. Therefore, it is necessary to improve the efficiency of magnetic flux capture by the magnetic body.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to improve the efficiency with which a magnetic body can capture magnetic flux.

[0006] The electric motor of the present disclosure 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 stator has a magnetic body portion attached to at least one axial end of the stator core and facing the rotor. The magnetic body portion is formed of a laminated body made of multiple electromagnetic steel plates and is curved along the outer circumferential surface of the rotor.

[0007] According to the present disclosure, the magnetic body portion is made of laminated electromagnetic steel sheets and curved along the outer circumferential surface of the rotor, thereby reducing iron loss in the magnetic body portion and efficiently drawing the rotor's magnetic flux from the magnetic body portion into the stator core, thereby improving the output of the electric motor.

[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 a molded resin portion and coils omitted; FIG. 3 is a perspective view showing a stator core and a magnetic material portion according to the first embodiment; FIG. 4 is a perspective view showing a portion of the stator core and the magnetic material portion according to the first embodiment; FIG. 5 is a plan view (A) showing a portion of the stator core and the magnetic material portion according to the first embodiment, and a schematic view (B) showing a holding structure for the magnetic material portion; FIG. 6 is a schematic view showing the flow of magnetic flux in the stator core and the magnetic material portion according to the first embodiment; FIG. 7 is a view of the stator core and the magnetic material portion according to the first embodiment, as seen from the rotor side; FIG. 8 is a cross-sectional view (A) showing the magnetic material portion according to the first embodiment together with surrounding members, and a perspective view (B) showing the magnetic material portion; FIG. 9 is a view of the stator core and the magnetic material portion according to the first embodiment, as seen from the rotor side; FIG. 10 is a plan view (A) and a cross-sectional view (B) showing an example of a method of fixing electromagnetic steel sheets by crimping according to the first embodiment; FIG. 11 is a plan view (A) and a cross-sectional view (B) showing another example of a method of fixing electromagnetic steel sheets by crimping according to the first embodiment; 18A and 18B are diagrams showing the position of a crimped portion in a magnetic material portion of the first embodiment. It is a flowchart showing a manufacturing method of an electric motor of the first embodiment. It is a cross-sectional view showing another configuration example of an electric motor of the first embodiment. It is a cross-sectional view showing a part of a stator core and a magnetic material portion of the electric motor of FIG. 15. It is a plan view showing a stator core, a magnetic flux take-in member, and a rotor of the second embodiment. It is a view of the stator of the second embodiment as seen from the rotor side. It is a diagram showing the opposing surfaces of the magnetic material portion of the second embodiment, and a diagram showing the opposing surfaces of a connecting portion. It is a diagram showing the cross-sectional shape of the magnetic material portion of the second embodiment, and a diagram showing the cross-sectional shape of a connecting portion. It is a cross-sectional view of the magnetic flux take-in member of the second embodiment, taken along line 21A-21A in FIG. 18A, and a cross-sectional view of the magnetic flux take-in member of the second embodiment, taken along line 21B-21B in FIG. It is a plan view showing an electromagnetic steel sheet constituting the magnetic material portion of the second embodiment. Fig. 10 is a plan view showing a stator core, magnetic flux take-in member, and rotor according to a modified example of embodiment 2. Fig. 11 is a cross-sectional view showing a connection portion of the magnetic flux take-in member according to a modified example of embodiment 2. Fig. 12 is a plan view showing a stator core, magnetic flux take-in member, and rotor according to embodiment 3. Fig. 13 is a flowchart showing a method for manufacturing the electric motor according to embodiment 3.Fig. 10 is a plan view showing a stator core, a magnetic flux intake member, and a rotor according to embodiment 4. Fig. 11 is a plan view showing an electromagnetic steel plate constituting a magnetic body part according to embodiment 4. Fig. 12 is a cross-sectional view showing an electric motor according to embodiment 5. Fig. 13 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 material portion 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 material portion 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 electromagnetic steel sheets 101 (FIG. 8A) are stacked in the axial direction. The thickness of the electromagnetic steel sheets 101 is, for example, 0.1 mm to 1.0 mm.

[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 is made of copper or aluminum wire and is wound around the coil winding portion 22 via an insulating portion 40. The coil 25 is wound by concentrated winding, for example, 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 and the magnetic material portion 31. 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 material portion 31 is provided on at least one axial end face 23c of the tooth tip portion 23. In the example shown in Fig. 3, the magnetic material portions 31 are provided on both end faces 23c of the tooth tip portion 23. In this case, the number of magnetic material portions 31 (M) is twice the number of the tooth tip portions 23 (i.e., 2N).

[0031] However, the magnetic material portions 31 may be provided only on one end surface 23c of the tooth tip portion 23 (see FIGS. 15 and 16). In this case, the number of magnetic material portions 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 material portion 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 material portion 31 provided on the other end face 23c (lower face in Figure 3), but these lengths may be the same or may be reversed.

[0033] The magnetic body portion 31 faces the rotor 10 (FIG. 2) in the radial direction. The magnetic body portion 31 is formed of a magnetic material, more specifically, a laminate of electromagnetic steel sheets, which will be described later. The magnetic body portion 31 takes in the magnetic flux of the rotor 10 and guides it to the stator core 20, as will be described later, 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 material portion 31. Fig. 5(A) is a plan view showing a portion of the stator core 20 and the magnetic material portion 31.

[0035] As shown in Figures 4 and 5(A), the magnetic material portion 31 has an opposing surface 31a facing the rotor 10, a back surface 31b facing the yoke 21, an axial end (referred to as the axial end) 31c, and a circumferential end (referred to as the circumferential end) 31e.

[0036] It is desirable that the radial position of the opposing surface 31 a of the magnetic material portion 31 coincides with the radial position of the opposing surface 23 a of the tooth tip portion 23. Like the opposing surface 23 a of the tooth tip portion 23, the opposing surface 31 a of the magnetic material portion 31 is exposed from the molded resin portion 50 ( FIG. 1 ) to the rotor 10 side.

[0037] When magnetic material portions 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 material portion 31 and the area S1b of the opposing surface 31a of the other magnetic material portion 31 (S1 = S1a + S1b) is greater than the area S2 of the opposing surface 23a of the tooth tip 23. In other words, S1 > S2 holds. This allows more magnetic flux from the rotor 10 to flow into the magnetic material portions 31.

[0038] Furthermore, the sum H1 (= H1a + H1b) of the axial length H1a of the opposing surface 31a of one magnetic material portion 31 and the axial length H1b of the opposing surface 31a of the other magnetic material portion 31 is longer than the axial length H2 of the opposing surface 23a of the tooth tip portion 23. In other words, H1 > H2 holds. This allows more magnetic flux from the rotor 10 to flow into the magnetic material portion 31.

[0039] Furthermore, the circumferential width W1 of the opposing surface 31 a of the magnetic material portion 31 is narrower than the circumferential width W2 of the opposing surface 23 a of the tooth tip portion 23. In other words, W1 < W2 holds true. This prevents contact between circumferentially adjacent tooth tip portions 23 and suppresses magnetic flux leakage between them.

[0040] 5A, the magnetic material portion 31 is curved along the outer peripheral surface of the rotor 10. Here, the magnetic material portion 31 is curved in an arc shape with a concave side facing the rotor 10. In other words, the magnetic material portion 31 is curved so that the distance between its facing surface 31 a and the rotor 10 is constant in the circumferential direction.

[0041] More specifically, the opposing surface 31 a of the magnetic material portion 31 is curved along the outer circumferential surface of the rotor 10, and the back surface 31 b of the magnetic material portion 31 is also curved in the same manner as the opposing surface 31 a. The radial thickness of the magnetic material portion 31 (i.e., the distance between the opposing surface 31 a and the back surface 31 b) is constant in the circumferential direction.

[0042] 5B is a cross-sectional view schematically showing the holding structure of the magnetic material portion 31. The flange portion 43 of the insulating portion 40 described above is located radially outward of the magnetic material portion 31. The flange portion 43 is formed with a wall portion 43a that abuts against the circumferential end portion 31e of the magnetic material portion 31. The magnetic material portion 31 is held by being sandwiched from both sides in the circumferential direction by the wall portions 43a of the insulating portion 40.

[0043] <Magnetic Path in Stator Core> Fig. 6 is a schematic diagram showing the flow of magnetic flux in the stator core 20 and the magnetic material portion 31. Fig. 7 is a view of the stator core 20 as viewed from the rotor 10 side. As shown in Fig. 6, the opposing surfaces 23a of the tooth tips 23 of the stator core 20 face the rotor 10. In addition, the opposing surfaces 31a of the magnetic material portions 31 also face the rotor 10.

[0044] A magnetic flux F2 flows from the rotor 10 into the opposing surface 31a of the magnetic material portion 31. The magnetic flux F2 that flows into the magnetic material portion 31 flows axially within the magnetic material portion 31 and flows into the tooth tip portion 23 of the stator core 20. In addition, a magnetic flux F1 also flows into the tooth tip portion 23 from the rotor 10 via the opposing surface 23a. These magnetic fluxes F1 and F2 flow through the coil winding portion 22 toward the yoke 21.

[0045] In this way, the magnetic material portion 31 serves as a magnetic path that guides the magnetic flux of the rotor 10 to the stator core 20. Because a large amount of magnetic flux flows within the magnetic material portion 31, loss (i.e., iron loss) generated in the magnetic material portion 31 becomes a problem. To avoid interference with the coil 25 wound around the coil winding portion 22, the radial thickness of the magnetic material portion 31 cannot be made too thick. On the other hand, to take in as much of the magnetic flux of the rotor 10 as possible, it is desirable that the circumferential and axial dimensions of the magnetic material portion 31 be as large as possible.

[0046] Therefore, the magnetic material portion 31 is long in the axial and circumferential directions and thin in the radial direction. Magnetic flux flows in the axial direction in the magnetic material portion 31, but because the magnetic material portion 31 is thin in the radial direction, it is not possible to ensure a sufficient cross-sectional area (i.e., the product of the circumferential width and the radial width) in a plane perpendicular to the magnetic path of the magnetic material portion 31, resulting in a high magnetic flux density. As a result, the proportion of iron loss generated by the magnetic flux flowing through the magnetic material portion 31 increases.

[0047] Therefore, it is desirable to configure the magnetic material portion 31 using a thin electromagnetic steel plate, which is used for the stator core 20, etc. By configuring the magnetic material portion 31 using an electromagnetic steel plate, iron loss in the magnetic material portion 31 can be suppressed.

[0048] <Configuration of magnetic body> Fig. 8(A) is a cross-sectional view showing an example of the configuration of the magnetic body portion 31 together with surrounding members. The symbol Rin indicates the radially inner side, and Rout indicates the radially outer side. Fig. 8(B) is a perspective view showing the magnetic body portion 31. Fig. 9 is a view of the stator core 20 and the magnetic body portion 31 as seen from the rotor 10 side.

[0049] 8A, the magnetic material portion 31 is formed of a laminated body of a plurality of electromagnetic steel sheets 102. The direction in which the electromagnetic steel sheets 102 are stacked is the direction in which the magnetic material portion 31 faces the rotor 10, i.e., the radial direction. The thickness of the electromagnetic steel sheets 102 is, for example, 0.1 mm to 1.0 mm.

[0050] Because the lamination direction of the electromagnetic steel sheets 101 of the stator core 20 is the axial direction, it is also conceivable to set the lamination direction of the electromagnetic steel sheets 102 of the magnetic body portion 31 to the axial direction. However, because the magnetic body portion 31 is thin in the radial direction, it is difficult to laminate the electromagnetic steel sheets 102 in the axial direction, and the yield during press working is also low.

[0051] Furthermore, because magnetic flux flows in the axial direction in the magnetic material portion 31 (see FIG. 6 ), when the electromagnetic steel sheets 102 of the magnetic material portion 31 are stacked in the axial direction, the magnetic flux passes through gaps (also referred to as lamination gaps) between the electromagnetic steel sheets 102 as it flows axially inside the magnetic material portion 31 toward the tooth tips 23. The magnetic resistance of the lamination gaps reduces the efficiency with which the magnetic flux is taken into the stator core 20.

[0052] 8A, the electromagnetic steel sheets 102 that make up the magnetic material portion 31 are laminated in a direction in which the magnetic material portion 31 faces the rotor 10 (i.e., in the radial direction). In this case, when the magnetic flux flows axially within the magnetic material portion 31 toward the tooth tips 23, it does not pass through the gaps between the electromagnetic steel sheets 102. Therefore, the magnetic flux can be efficiently taken into the stator core 20 without being affected by the magnetic reluctance of the lamination gaps.

[0053] On the other hand, if the flat electromagnetic steel plates 102 are simply stacked in the radial direction, the distance between the magnetic material portion 31 and the cylindrical rotor 10 will be uneven in the circumferential direction, and the amount of magnetic flux taken in from the rotor 10 will be reduced.

[0054] 8B, the magnetic material portion 31 has a curved shape that follows the outer periphery of the rotor 10. This makes the gap between the magnetic material portion 31 and the rotor 10 uniform in the circumferential direction, improving the efficiency of taking in magnetic flux from the rotor 10 to the magnetic material portion 31. In other words, the utilization efficiency of the magnetic flux of the rotor 10 is improved, and the output of the electric motor 1 can be improved.

[0055] On the other hand, in order to form the curved magnetic material portion 31, it is necessary to laminate and fix together the electromagnetic steel sheets 102 punched by press working, and then curve the laminate.

[0056] Therefore, the electromagnetic steel sheets 102 need to be fixed in a manner that prevents the electromagnetic steel sheets 102 from peeling off due to springback when the laminate is bent, or prevents the gaps between the laminated sheets from widening. Methods for fixing the electromagnetic steel sheets 102 include caulking and welding.

[0057] Crimping is a method of fixing multiple electromagnetic steel sheets by plastically deforming the sheets in the stacking direction and forcing them into adjacent sheets in the axial direction. Because the stacking and fixing are also performed during the stamping process of the electromagnetic steel sheets, the processing process can be simplified.

[0058] It should be noted that "crimping" refers to the method of fixing a plurality of electromagnetic steel sheets together as described above, whereas "crimped portion" refers to the uneven portion formed on the electromagnetic steel sheets during crimping.

[0059] Fig. 10A is a plan view illustrating an example of a method for fixing by crimping the electromagnetic steel plate 102 that constitutes the magnetic material part 31. Fig. 10B is a cross-sectional view taken along arrow 10B-10B in Fig. 10A.

[0060] When bending a laminate in which electromagnetic steel sheets 102 are stacked and fixed, gaps are likely to occur between the electromagnetic steel sheets due to springback of the electromagnetic steel sheets, which may reduce the fixing force provided by the crimping. In order to improve the fixing force (also referred to as fastening force) of the electromagnetic steel sheets provided by the crimping, it is desirable to increase the crimping depth.

[0061] There are two types of crimping: V-shaped crimping and round crimping. V-shaped crimping is preferable to achieve a sufficiently deep crimping depth. In V-shaped crimping, a rectangular crimped portion 31f is formed in the electromagnetic steel sheet 102.

[0062] 10(A), two parallel cuts CL of the same length are formed in the electromagnetic steel sheet 102, and as shown by the arrow in Fig. 10(B), a portion E1 between the two cuts CL of the electromagnetic steel sheet 102 is pressed in the stacking direction to plastically deform it. The length D1 of each cut CL corresponds to the length of the crimped portion 31f, and the distance D2 between the two cuts CL corresponds to the width of the crimped portion 31f.

[0063] The portion E1 of the electromagnetic steel sheet 102 sandwiched between the two cuts CL is connected to the surrounding portions only at connecting portions E2 on both sides of the portion E1 in the direction of length D1. This allows the crimping depth d1 to be increased, thereby increasing the fixing force of the electromagnetic steel sheet 102. Furthermore, the contact area between the electromagnetic steel sheets 102 can be adjusted by changing the length D1 of the cuts CL.

[0064] Fig. 11(A) is a plan view illustrating another example of a method for fixing the electromagnetic steel sheet 102 that constitutes the magnetic material part 31 by crimping. Fig. 11(B) is a cross-sectional view taken along arrow 11B-11B in Fig. 11(A). In the example shown in Fig. 11(A), the electromagnetic steel sheet 102 is fixed by round crimping. In round crimping, a circular crimped portion 31f is formed on the electromagnetic steel sheet 102. The diameter of the crimped portion 31f is defined as D.

[0065] In the case of round crimping, it is not possible to form a notch CL (FIG. 10A) like in V crimping in the electromagnetic steel sheet 102. In other words, with the entire outer periphery of the crimped portion 31f connected to the surrounding electromagnetic steel sheet 102, the inner portion E of the crimped portion 31f is pressed in the stacking direction and plastically deformed.

[0066] 11B, the crimping depth d2 in the case of round crimping is smaller than the crimping depth d1 (FIG. 10B) in the case of V crimping. In other words, it is more difficult to improve the fixing force of the electromagnetic steel sheet 102 with round crimping than with V crimping.

[0067] Therefore, in order to avoid the widening of the gap between the laminated layers when the laminate of the electromagnetic steel sheets 102 is bent, it is desirable to fix the laminated layers by V-shaped crimping as shown in FIGS.

[0068] On the other hand, when the degree of curvature of the magnetic material part 31 is relatively small (for example, when the radius of curvature of the magnetic material part 31 is large), it is also possible to fix the electromagnetic steel plate 102 by round caulking.

[0069] 12 is a diagram for explaining the position of the crimped portion 31f in the magnetic material portion 31. It is desirable that the crimped portion 31f is not positioned too close to the axial end portion 31c and the circumferential end portion 31e of the magnetic material portion 31.

[0070] The shortest distance G1 between the crimped portion 31f and the axial end 31c of the magnetic material portion 31 is preferably equal to or greater than the thickness of the electromagnetic steel sheet 102. Similarly, the shortest distance G2 between the crimped portion 31f and the circumferential end 31e of the magnetic material portion 31 is preferably equal to or greater than the thickness of the electromagnetic steel sheet 102.

[0071] If the shortest distances G1 and G2 are too short, the strength of the electromagnetic steel sheet 102 may be partially reduced, and the fixing force may be reduced. Also, the pressing force of the crimping may cause the axial end 31 c to bulge outward in the axial direction, or the circumferential end 31 e to bulge outward in the circumferential direction.

[0072] 9, it is most desirable that the crimped portion 31f be located at the circumferential center (indicated by the dashed line T) of the magnetic material portion 31. When the laminate of the electromagnetic steel sheets 102 is curved, misalignment of the circumferential ends of the electromagnetic steel sheets 102 occurs between the opposing surface 31a side and the back surface 31b side of the magnetic material portion 31. By locating the crimped portion 31f at the circumferential center of the magnetic material portion 31, it is possible to minimize the misalignment of the circumferential ends of the electromagnetic steel sheets 102.

[0073] Fig. 13(A) is a diagram showing an example of a fixing method by welding the electromagnetic steel sheets 102. In the example shown in Fig. 13(A), the axial ends of the electromagnetic steel sheets 102 (i.e., the axial end 31c of the magnetic material portion 31) are welded as shown by the symbol WD1, and the circumferential ends of the electromagnetic steel sheets 102 (i.e., the circumferential end 31e of the magnetic material portion 31) are welded as shown by the symbol WD2.

[0074] In this example, the entire outer periphery of the electromagnetic steel sheet 102 is welded, but only the axial end (symbol WD1) of the electromagnetic steel sheet 102 may be welded, or only the circumferential end (symbol WD2) may be welded.

[0075] On the other hand, as described above, when the laminate of electromagnetic steel sheets 102 is curved, misalignment occurs between the circumferential ends of the electromagnetic steel sheets 102 on the opposing surface 31 a side and the back surface 31 b side. Therefore, it is desirable to weld only the centers of the axial ends 31 c of the electromagnetic steel sheets 102, as shown by symbol WD1 in Figure 13(B) .

[0076] As shown in Figures 5B and 8A, the magnetic material portion 31 is fixed to the stator core 20 by the flange portion 43 of the insulating portion 40. The flange portion 43 holds the magnetic material portion 31 from the radial outside and also from both sides in the circumferential direction.

[0077] 14 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 electromagnetic steel sheets 101 in the axial direction and fixing them by caulking or the like.

[0078] In step S12, the magnetic material portion 31 is formed. The magnetic material portion 31 is formed by stacking the electromagnetic steel sheets 102 as described above, fixing them by caulking or welding to form a laminate, and then bending the laminate. Note that step S12 may be performed before step S11.

[0079] In step S13 , the magnetic material portion 31 is attached to the end face 23 c of each tooth tip 23 of the stator core 20 .

[0080] In step S14, the insulating portion 40 is attached to the stator core 20. The insulating portion 40 may be formed by integrally molding resin together with the stator core 20 and the magnetic material portion 31, or may be attached to the stator core 20 after being molded in advance.

[0081] By attaching the insulating portion 40 to the stator core 20, the magnetic material portion 31 is held from the radially outer side and both circumferential sides by the flange portions 43 of the insulating portion 40 (see FIGS. 5B and 8A). Steps S13 and S14 correspond to steps of fixing the magnetic material portion 31.

[0082] In step S15, the coil 25 is wound around the coil winding portion 22 with the insulating portion 40 interposed therebetween.

[0083] In step S16, the stator core 20, the magnetic material portion 31, the insulating portion 40, and the coil 25 are molded. Specifically, the stator core 20, the magnetic material portion 31, the insulating portion 40, and the coil 25 are placed in a mold, and molding resin is injected. This forms the molding resin portion 50 that covers the stator core 20, the magnetic material portion 31, the insulating portion 40, and the coil 25, and the stator 2 is completed.

[0084] In step S17, 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.

[0085] In step S18, 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.

[0086] 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.

[0087] Fig. 15 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. 15, the magnetic material portion 31 is provided on only one side of the stator core 20 in the axial direction.

[0088] Specifically, the rotor 10 protrudes more from the stator core 20 on the load side, and the magnetic material portion 31 is provided on the load side of the stator core 20. The shape of the magnetic material portion 31 is as described above. In this case, too, the magnetic flux of the rotor 10 can be efficiently taken in from the magnetic material portion 31 to the stator core 20.

[0089] 16 is a perspective view showing a part of the stator core 20 and the magnetic material portion 31 according to the first embodiment. The magnetic material portion 31 is attached to one end surface 23c of the tooth tip portion 23 of the stator core 20.

[0090] An area S1 of the opposing surface 31a of the magnetic material portion 31 that faces the rotor 10 is larger than an area S2 of the opposing surface 23a of the tooth tip portion 23 that faces the rotor 10. Furthermore, an axial length H1 of the opposing surface 31a of the magnetic material portion 31 is larger than an axial length H2 of the opposing surface 23a of the tooth tip portion 23. This allows the magnetic flux of the rotor 10 to be taken in from the magnetic material portion 31 to the stator core 20 more efficiently.

[0091] <Effects of First Embodiment> As described above, in the electric motor 1 of the first embodiment, the stator 3 has the magnetic material portion 31 attached to at least one axial end of the stator core 20, and the magnetic material portion 31 is formed of a laminate of stacked electromagnetic steel sheets 102 and is curved along the outer peripheral surface of the rotor 10. This reduces iron loss in the magnetic material portion 31 and allows the magnetic flux of the rotor 10 to be efficiently taken in from the magnetic material portion 31 to the stator core 20. In other words, the utilization efficiency of the magnetic flux of the rotor 10 is improved, and the output of the electric motor 1 can be improved.

[0092] Furthermore, since the multiple electromagnetic steel plates 102 of the magnetic material portion 31 are stacked radially, the magnetic resistance in the magnetic material portion 31 can be reduced, and the amount of magnetic flux that can be taken in by the stator core 20 can be increased.

[0093] Furthermore, since the plurality of electromagnetic steel sheets 102 of the magnetic material portion 31 are fixed by the crimped portions 31f, it is possible to make it difficult for the lamination gaps between the electromagnetic steel sheets 102 to widen due to the influence of springback.

[0094] Furthermore, since the crimping portion 31f has a notch CL on its outer periphery and is plastically deformed in the stacking direction, the crimping depth d1 can be made deeper, thereby improving the fixing force for fixing the electromagnetic steel sheet 102.

[0095] Furthermore, if the crimping portion 31f does not have a notch CL on its outer periphery and is plastically deformed in the stacking direction, the crimping depth d2 will be relatively shallow, but if the degree of curvature of the magnetic material portion 31 is relatively small, the electromagnetic steel plate 102 can be sufficiently fixed.

[0096] Furthermore, since the shortest distance G1 from the crimping portion 31f to the axial end 31c of the magnetic material portion 31 and the shortest distance G2 from the crimping portion 31f to the circumferential end 31e of the magnetic material portion 31 are both greater than the thickness of the electromagnetic steel plate 102, the axial end 31c or the circumferential end 31e is prevented from bulging outward due to the pressing force applied during crimping, thereby preventing a decrease in the fixing force.

[0097] Furthermore, since the crimped portion 31f is provided in the circumferential center of the magnetic material portion 31, it is possible to minimize the positional deviation of the circumferential end portion of the electromagnetic steel plate 102 when the laminate of the electromagnetic steel plate 102 is bent.

[0098] Furthermore, by fixing the plurality of electromagnetic steel sheets 102 of the magnetic material portion 31 by welding, it is possible to make it difficult for the lamination gaps between the electromagnetic steel sheets 102 to widen due to the influence of springback.

[0099] In addition, by welding multiple electromagnetic steel sheets 102 to at least one of the axial end 31c and the circumferential end 31e of the magnetic material portion 31, it is possible to prevent the lamination gaps between the electromagnetic steel sheets 102 from widening due to the effect of springback.

[0100] In addition, by welding multiple electromagnetic steel plates 102 at the center of the axial end 31c of the magnetic material portion 31, it is possible to minimize the positional deviation of the circumferential end of the electromagnetic steel plates 102 when the laminate of the electromagnetic steel plates 102 is bent.

[0101] Furthermore, since the rotor 10 protrudes from the stator core 20 on at least one side in the axial direction and faces the magnetic material portion 31, the magnetic flux emitted from the protruding portion of the rotor 10 can be efficiently taken in from the magnetic material portion 31 to the stator core 20.

[0102] Furthermore, since the magnetic material portion 31 is held by the insulating portion 40, which serves as a first insulating member provided on the stator core 20, the magnetic material portion 31 can be held immovable against the magnetic attraction force acting between the rotor 10 and the magnetic material portion 31.

[0103] Furthermore, since the magnetic material portion 31 and the stator core 20 are held by the insulating portion 40 serving as the second insulating member, the magnetic material portion 31 can be held together with the stator core 20 more firmly.

[0104] Embodiment 2. Figure 17 is a plan view showing the coil winding portions 22, tooth tips 23, and magnetic flux intake members 30 of a stator 2A of an electric motor 1A according to embodiment 2, as well as the rotor 10. The electric motor 1A according to embodiment 2 differs from the electric motor 1 according to embodiment 1 in that circumferentially adjacent magnetic material portions 31 are connected by connecting portions 32. Note that in Figure 17, only the outer peripheral surface 10a of the rotor 10 is shown.

[0105] The magnetic material portions 31 and the connecting portions 32 are integrally formed. The magnetic material portions 31 and the connecting portions 32 are collectively referred to as the magnetic flux intake member 30. If the number of magnetic material portions 31 is M (M is an integer of 2 or greater), then in FIG. 17 , the M magnetic material portions 31 are connected by the connecting portions 32 to form the integrated magnetic flux intake member 30. However, it is sufficient that at least two of the M magnetic material portions 31 are connected by the connecting portions 32.

[0106] The connecting portion 32 extends radially outward beyond the magnetic material portion 31. An opposing surface 31a of the magnetic material portion 31 is exposed from the molded resin portion 50 (FIG. 18), whereas the connecting portion 32 is covered by the molded resin portion 50.

[0107] The shape of the magnetic material portion 31 is as described in embodiment 1. The connecting portion 32 has 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 material portion 31.

[0108] Fig. 18 is a view of the stator 2A as seen from the rotor 10 side. In Fig. 18, the magnetic flux take-in member 30 is provided at one axial end of the stator core 20. However, the magnetic flux take-in member 30 may be provided at both axial ends of the stator core 20.

[0109] The connecting portion 32 is connected to the upper end of the magnetic material portion 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.

[0110] 19A is a schematic diagram illustrating the area J1 of the opposing surface 31a of the magnetic material portion 31. The opposing surface 31a of the magnetic material portion 31 has a length T1 in the axial direction and a width U1 in the circumferential direction. The area J1 of the opposing surface 31a of the magnetic material portion 31 is T1 × U1.

[0111] 19(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.

[0112] The area J1 of the opposing surface 31 a of the magnetic material portion 31 is larger than the area J2 of the opposing surface 32 a of the connecting portion 32. In other words, J1 > J2 holds true. Therefore, the magnetic flux flowing from the rotor 10 to the opposing surface 32 a of the connecting portion 32 is small, and the magnetic flux flowing to the opposing surface 31 a of the magnetic material portion 31 is large.

[0113] 20A is a schematic diagram illustrating the cross-sectional area K1 of the magnetic material portion 31. The cross-sectional area K1 of the magnetic material portion 31 is the cross-sectional area in a plane perpendicular to the circumferential direction. The magnetic material portion 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 material portion 31 is T1 x V1.

[0114] 20(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.

[0115] The cross-sectional area K2 of the connecting portion 32 is smaller than the cross-sectional area K1 of the magnetic material portion 31. In other words, K1 > K2 holds true. Therefore, magnetic flux is less likely to flow through the connecting portion 32, and thus leakage magnetic flux between adjacent magnetic material portions 31 is reduced.

[0116] Figure 21(A) is a cross-sectional view of the stator 2A and the rotor 10 taken along line 21A-21A in Figure 18. Figure 21(B) is a cross-sectional view of the stator 2A and the rotor 10 taken along line 21B-21B in Figure 18. In Figures 21(A) and 21(B), the radially inner side is indicated by an arrow Rin, and the radially outer side is indicated by an arrow Rout.

[0117] 21A, the opposing surface 31a of the magnetic material portion 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 material portion 31 is C1.

[0118] 21B, 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.

[0119] 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 material portion 31. This makes it difficult for magnetic flux from rotor 10 to reach connecting portion 32. In addition, because the rotor 10 side of connecting portion 32 is covered with molded resin portion 50, deformation or peeling of connecting portion 32 due to the magnetic attraction force with rotor 10 is prevented.

[0120] The magnetic material portion 31 and the connecting portion 32 are configured by laminated layers of electromagnetic steel sheets 102. The lamination direction of the electromagnetic steel sheets 102 in the magnetic material portion 31 and the connecting portion 32 is the radial direction. Therefore, the magnetic flux heading toward the tooth tip portion 23 within the magnetic material portion 31 does not pass through the lamination gaps of the electromagnetic steel sheets 102, and therefore the magnetic flux can be efficiently taken into the stator core 20.

[0121] Furthermore, by making the number of electromagnetic steel sheets 102 forming the connecting portion 32 smaller than the number of electromagnetic steel sheets 102 forming the magnetic material portion 31, the radial width V2 of the connecting portion 32 can be made narrower than the radial width V1 of the magnetic material portion 31. This will be described later (see FIG. 24 ).

[0122] The manufacturing method of the electric motor 1A of embodiment 2 is the same as that described in embodiment 1 with reference to Figure 14, but in step S12 (Figure 14), electromagnetic steel plates 102 are stacked to form a magnetic flux intake member 30 consisting of a magnetic material portion 31 and a connecting portion 32.

[0123] Fig. 22 is a plan view showing the electromagnetic steel sheets 102 that form the magnetic flux take-in member 30. The magnetic flux take-in member 30 is formed by stacking the electromagnetic steel sheets 102 in the radial direction. In the electromagnetic steel sheets 102, M magnetic material portions 31 and M connecting portions 32 are arranged alternately in a strip shape. In Fig. 22, the direction of the rotation axis Ax is indicated by arrow Z.

[0124] The electromagnetic steel sheets 102 are stacked in the radial direction and fixed by crimping or welding to form a laminate. The crimping and welding methods are as described in embodiment 1. The laminate is bent into an annular shape, and the connecting portions 32 located at both ends of the electromagnetic steel sheets 102 are welded (indicated by the symbol WD in FIG. 17 ), thereby forming the magnetic flux intake member 30 shown in FIG. 17 .

[0125] In the process of attaching the magnetic flux intake member 30 to the stator core 20 (step S13 shown in Figure 14), the magnetic flux intake member 30 including M magnetic material portions 31 can be handled as a single unit, making the manufacturing process simpler.

[0126] Although all of the M magnetic material parts 31 are connected by the connecting parts 32 in this example, it is sufficient if at least two magnetic material parts 31 are connected by the connecting parts 32. In this case as well, the two magnetic material parts 31 can be handled as a single component, which simplifies the manufacturing process of the electric motor 1 and improves productivity.

[0127] Furthermore, the connecting portion 32 of the second embodiment does not necessarily have to be formed integrally with the magnetic material portion 31. The connecting portion 32 may be formed of a magnetic material other than an electromagnetic steel plate.

[0128] 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.

[0129] As described above, in the electric motor 1A of the second embodiment, at least two of the M magnetic material parts 31 are connected by the connecting parts 32, which makes it possible to more reliably hold the magnetic material parts 31. Furthermore, in the manufacturing process of the electric motor 1A, the at least two magnetic material parts 31 can be handled as a single unit, which simplifies the manufacturing process.

[0130] Furthermore, since the distance C2 between the connecting portion 32 and the rotor 10 is longer than the distance C1 between the magnetic material portion 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.

[0131] 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 material portion 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 material portion 31 can be increased.

[0132] Furthermore, since the cross-sectional area K2 of the connecting portion 32 is smaller than the cross-sectional area K1 of the magnetic material portion 31 (K1>K2), magnetic flux leakage between the magnetic material portions 31 via the connecting portion 32 can be suppressed.

[0133] 23 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux intake member 30 of a stator 2B of an electric motor 1B according to a modification of the second embodiment, and the rotor 10. The electric motor 1B of the second embodiment differs from the electric motor 1A of the second embodiment in that the radial width V2 of the connecting portion 32B is narrower than the radial width V1 of the magnetic material portion 31.

[0134] Since the radial width V2 of the connecting portion 32B is narrower than the radial width V1 of the magnetic material portion 31, the cross-sectional area of ​​the connecting portion 32B is sufficiently smaller than the cross-sectional area of ​​the magnetic material portion 31, thereby enhancing the effect of suppressing magnetic flux leakage between adjacent magnetic material portions 31.

[0135] The magnetic flux intake member 30B, consisting of the magnetic material portion 31 and the connecting portion 32B, is formed of a laminate in which electromagnetic steel plates 102 are stacked in the radial direction, as described in embodiment 2 with reference to Figures 21 (A) and (B).

[0136] Figure 24 is a cross-sectional view showing the stator 2B and the rotor 10, and corresponds to the cross-sectional view taken along line 21B-21B in Figure 18. As shown in Figure 24, the number of electromagnetic steel sheets 102 forming the connecting portion 32B is smaller than the number of electromagnetic steel sheets 102 (Figure 21(A)) forming the magnetic material portion 31. This allows the radial width V2 of the connecting portion 32B to be narrower than the radial width V1 of the magnetic material portion 31.

[0137] In this case, it is desirable that the connecting portion 32B does not have any electromagnetic steel sheets 102 (shown by dashed lines in FIG. 24 ) that are the same as those in the magnetic material portion 31, but that are on the side away from the rotor 10, i.e., the radially outer electromagnetic steel sheets 102. In other words, it is desirable that the electromagnetic steel sheets that form the connecting portion 32B are connected to the electromagnetic steel sheets that form the magnetic material portion 31 and that are located on the radially inner side.

[0138] In this way, the connecting portion 32B connects the radially inner ends of adjacent magnetic material portions 31, thereby preventing displacement of the magnetic material portions 31 due to the magnetic attraction force with the rotor 10.

[0139] The connecting portion 32B in the modified example of the second embodiment does not necessarily have to be formed integrally with the magnetic material portion 31. The connecting portion 32B may be formed of a magnetic material other than an electromagnetic steel plate.

[0140] 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.

[0141] As described above, in the electric motor 1B according to the modified example of the second embodiment, the radial width V2 of the connecting portion 32B is narrower than the radial width V1 of the magnetic material portion 31, thereby suppressing magnetic flux leakage between adjacent magnetic material portions 31. Furthermore, the connecting portion 32B connects the radially inner ends of adjacent magnetic material portions 31 together, thereby preventing displacement of the magnetic material portions 31 due to magnetic attraction force.

[0142] Embodiment 3. Figure 25 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux take-up member 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 take-up member 30B (Figure 23) of the stator 2B according to the modified example of Embodiment 2 in that the connecting portion 32C of the magnetic flux take-up member 30C is cut off.

[0143] 25 , 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.

[0144] That is, in the magnetic flux intake member 30C, a pair of protrusions 37 is formed between two adjacent magnetic material portions 31. The pair of protrusions 37 has two protrusions 38 that are close to each other in the circumferential direction and extend radially outward.

[0145] 26 is a flowchart showing a manufacturing method of electric motor 1C of embodiment 3. In step S21, electromagnetic steel sheets are stacked in the axial direction and fixed by caulking or the like to assemble stator core 20 (FIG. 21(A)).

[0146] In step S22, as described in the second embodiment, magnetic steel sheets 102 are stacked and fixed by caulking or welding to form magnetic flux capture member 30C made up of magnetic material portion 31 and connecting portion 32C.

[0147] In step S23, magnetic flux take-in member 30C is attached to the end face of stator core 20. At this stage, magnetic flux take-in member 30C has the same shape as magnetic flux take-in member 30B (FIG. 23) of the modified example of Embodiment 2. That is, M magnetic material portions 31 are connected by connecting portions 32C.

[0148] In step S24, the insulating portion 40 is attached to the stator core 20. By attaching the insulating portion 40 to the stator core 20, the magnetic material portion 31 of the magnetic flux intake member 30C is held by the insulating portion 40 from the radially outer side and both circumferential sides.

[0149] In the next step S25, the connecting portion 32C of the magnetic flux intake member 30C is cut with a cutter or the like. By cutting the connecting portion 32C, a pair of protrusions 37 shown in FIG.

[0150] In subsequent steps S26 to S29, similar to steps S15 to S18 (FIG. 14) of 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.

[0151] In step S24, the M magnetic material portions 31 are connected by the connecting portions 32C, so that the magnetic flux intake member 30C can be handled as a single component. Furthermore, in step S25, the connecting portions 32C are cut, so that magnetic flux leakage between adjacent magnetic material portions 31 can be effectively suppressed. Furthermore, because the connecting portions 32C (i.e., the protrusion pairs 37) are covered with the molded resin portion 50 together with the magnetic material portions 31, the magnetic material portions 31 and the connecting portions 32C can be more reliably held in place.

[0152] Here, we have described an example in which M magnetic material parts 31 are connected by connecting part 32C, but it is sufficient if at least two magnetic material parts 31 are connected by connecting part 32C and the connecting part 32C is cut after attachment to the stator core 20.

[0153] In magnetic flux capture member 30C shown in Fig. 25, similar to magnetic flux capture member 30B (Fig. 23) 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 material portion 31. However, the radial widths of magnetic material portion 31 and connecting portion 32C may be the same.

[0154] Furthermore, the connecting portion 32C of the third embodiment does not necessarily have to be formed integrally with the magnetic material portion 31. The connecting portion 32C may be formed of a magnetic material other than an electromagnetic steel plate.

[0155] 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.

[0156] As described above, in electric motor 1C of embodiment 3, magnetic flux take-in member 30C having magnetic material portion 31 and connecting portion 32C is attached to stator core 20, and then connecting portion 32C is cut off. This simplifies handling of magnetic flux take-in member 30C when attaching it to stator core 20, and furthermore, cutting off connecting portion 32C effectively suppresses magnetic flux leakage.

[0157] 27 is a plan view showing the coil winding portion 22, tooth tip portion 23, and magnetic flux take-up member 30D of a stator 2D of an electric motor 1D according to embodiment 4, as well as the rotor 10. In the electric motor 1D according to embodiment 4, the configuration of the magnetic flux take-up member 30D differs from that of the magnetic flux take-up member 30 according to embodiment 2.

[0158] 27 , magnetic flux capture member 30D of the fourth embodiment has M (M is an integer of 2 or more) magnetic material portions 31 and M−1 connecting portions 32D. Of the M magnetic material portions 31, no connecting portion 32D is formed between two magnetic material portions 31 indicated by the symbol End. A non-connecting portion 39, which is a gap, is formed between the two magnetic material portions 31.

[0159] In other words, the magnetic flux intake member 30D is formed in an annular shape that extends in the circumferential direction around the rotation axis Ax and has both ends that face each other with the non-connecting portion 39 in between.

[0160] Fig. 28 is a plan view showing the electromagnetic steel sheets 102 that form magnetic flux intake member 30D. Magnetic flux intake member 30D is formed by laminating electromagnetic steel sheets 102 in the radial direction. In Fig. 28, arrow Z indicates the direction of rotation axis Ax.

[0161] In the electromagnetic steel sheet 102, M magnetic material portions 31 and M-1 connecting portions 32D are arranged in a strip shape. The magnetic material portions 31 indicated by the symbol End in Fig. 28 are located at both ends of the electromagnetic steel sheet 102 in the arrangement direction.

[0162] The magnetic flux intake member 30D shown in Fig. 27 is formed by stacking the electromagnetic steel sheets 102 shown in Fig. 28 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 material portions 31 located at both ends.

[0163] 23, by removing some of the electromagnetic steel sheets 102 forming the connecting portion 32D from the radially outer side, the radial width V2 of the connecting portion 32D can be made narrower than the radial width V1 of the magnetic material portion 31. Note that the radial widths of the magnetic material portion 31 and the connecting portion 32D may be the same.

[0164] In the fourth embodiment, M magnetic material portions 31 are connected by M-1 connecting portions 32D, and therefore can be handled as a single component. Furthermore, magnetic flux intake member 30D is formed by bending a laminated body formed by laminating strip-shaped electromagnetic steel sheets 102 as shown in FIG. 28 into a ring shape. This simplifies the manufacturing process of electric motor 1.

[0165] 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.

[0166] As described above, in electric motor 1D of embodiment 4, M magnetic material portions 31 and M-1 connecting portions 32D constitute magnetic flux take-in member 30D, which extends in the circumferential direction around rotation axis Ax, with both ends facing each other across non-connecting portions 39. Therefore, magnetic flux take-in member 30D can be formed by curving a laminate formed by stacking strip-shaped electromagnetic steel sheets 102, thereby simplifying the manufacturing process.

[0167] Fifth Embodiment Fig. 29 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 rotary shaft 15. A hub may be provided between the impeller 81 and the rotary shaft 15. The impeller 81 and the electric motor 1E constitute an outdoor fan 80 as a blower.

[0168] 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.

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] In the electric motor 1E of the fifth embodiment, the magnetic material portions 31 are provided on both axial ends of the stator core 20, so that a large amount of magnetic flux can be taken into the stator core 20 from the rotor 10 via the magnetic material portions 31. Note that the magnetic material portions 31 may be provided on only one axial end of the stator core 20.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] In addition, in the second to fifth embodiments and the modified examples, the magnetic part 31 and the connecting part 32 are integrally formed from the same material. However, the magnetic part 31 and the connecting part 32 may be formed from different materials.

[0178] <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. 30(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.

[0179] The outdoor unit 8 includes an outdoor fan 80 as a blower, an outdoor heat exchanger 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.

[0180] The indoor unit 9 includes an indoor fan 90 as a blower, an indoor heat exchanger 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.

[0181] 30(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.

[0182] 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 condenses in the outdoor heat exchanger 83 is released to the outside by the air blown by the outdoor blower 80.

[0183] In the indoor blower 90 (FIG. 30(A)), 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 indoor heat exchanger 93 is blown into the room by the indoor blower 90.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] REFERENCE SIGNS LIST 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, 22 Coil winding portion, 23 Tooth tip portion, 24 Slot, 25 Coil, 30, 30B, 30C, 30D Magnetic flux intake member, 31 Magnetic body portion, 31a Opposing surface, 31b Back surface, 31c Axial end portion, 31e Circumferential end portion, 31f Crimped portion, 32, 32B, 32C, 32D Connecting portion, 37 Protrusion pair, 38 Protrusion, 39 Non-connecting portion, 40 Insulating portion (first insulating member), 41 Wall portion, 42 Body portion, 43 Flange portion, 50 Molded resin portion (outer shell member, second insulating member), 80 Outdoor blower, 81 Impeller, 90 Indoor blower, 91 Impeller, 95 Electric motor, 101, 102 Electromagnetic steel plate.

Claims

1. An electric motor comprising: a rotor rotatable about a rotation axis; a stator having a stator core facing the rotor in a radial direction about the rotation axis; and a coil wound around the stator core; wherein the stator has a magnetic part attached to at least one end of the stator core in the axial direction of the rotation axis and facing the rotor; and the magnetic part is formed of a laminated body made of a plurality of stacked electromagnetic steel plates and is curved along the outer peripheral surface of the rotor.

2. The electric motor according to claim 1, wherein the plurality of electromagnetic steel sheets are stacked in the radial direction.

3. An electric motor according to claim 1 or 2, wherein the plurality of electromagnetic steel sheets are fixed at crimped portions and curved.

4. The electric motor according to claim 3, wherein the crimped portion has a notch on its outer periphery and is plastically deformed in the direction in which the plurality of electromagnetic steel sheets are laminated.

5. The electric motor according to claim 3, wherein the crimped portion has no notches on its outer periphery and is plastically deformed in the direction in which the plurality of electromagnetic steel sheets are laminated.

6. An electric motor as claimed in any one of claims 3 to 5, wherein the shortest distance from the crimped portion to the end of the magnetic material portion in the axial direction and the shortest distance from the crimped portion to the end of the magnetic material portion in the circumferential direction about the rotation axis are both equal to or greater than the thickness of each electromagnetic steel plate.

7. An electric motor according to any one of claims 3 to 6, wherein the crimped portion is formed at the center of the magnetic portion in the circumferential direction centered on the rotation axis.

8. The electric motor according to claim 1 or 2, wherein the plurality of electromagnetic steel plates are fixed by welding.

9. The electric motor according to claim 8, wherein the plurality of electromagnetic steel plates are welded to at least one of the axial end and the circumferential end of the magnetic part centered on the rotation axis.

10. An electric motor according to claim 8 or 9, wherein the welded portion for welding the plurality of electromagnetic steel plates is provided at the center of the axial end of the magnetic material portion.

11. The electric motor according to any one of claims 1 to 10, wherein the rotor protrudes from the stator core to at least one side in the axial direction of the rotary shaft.

12. The electric motor according to any one of claims 1 to 11, further comprising a first insulating member provided on the stator core and fixing the magnetic material portion.

13. The electric motor according to claim 12, further comprising a second insulating member that holds the magnetic portion, the stator core, and the first insulating member.

14. An electric motor as claimed in any one of claims 1 to 13, having a connecting portion protruding from an end of the magnetic material portion in a circumferential direction centered on the rotation axis, wherein a distance C1 from the rotor to the magnetic material portion and a distance C2 from the rotor to the connecting portion satisfy C1 < C2.

15. The electric motor according to claim 14, further comprising an insulating member that holds the magnetic body and the stator core together, and at least the surface of the connecting portion that faces the rotor is covered with the insulating member.

16. An electric motor according to claim 14 or 15, wherein a cross-sectional area K1 of the magnetic material portion in a plane perpendicular to the circumferential direction and a cross-sectional area K2 of the connecting portion in a plane perpendicular to the circumferential direction satisfy K1 > K2.

17. An electric motor according to any one of claims 14 to 16, wherein the area J1 of the surface of the magnetic material portion facing the rotor and the area J2 of the surface of the connecting portion facing the rotor satisfy the relationship J1 > J2.

18. An electric motor as claimed in any one of claims 14 to 17, wherein the magnetic material portion is one of M magnetic bodies (M is an integer of 2 or more) arranged in the circumferential direction, and at least two of the M magnetic bodies are connected by the connecting portion.

19. An electric motor as set forth in any one of claims 18 to 19, wherein a magnetic flux intake member is formed by the M magnetic bodies and M-1 connecting portions, and the magnetic flux intake member extends in the circumferential direction and is formed in an annular shape with both ends facing each other across non-connecting portions.

20. An electric motor according to any one of claims 14 to 19, wherein the connecting portion is made of a laminate of electromagnetic steel sheets.

21. An electric motor as set forth in claim 20, wherein the lamination direction of the electromagnetic steel sheets in the connecting portion is the radial direction, and the number of laminated electromagnetic steel sheets in the connecting portion is less than the number of laminated electromagnetic steel sheets in the magnetic material portion.

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

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

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

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