Stator and rotating electric machine

Abstract

A stator (11) is provided with a stator core (20), a bobbin (30), a coil (40), and a pressing member (50). The stator core (20) is formed from a plurality of core sheets (24) stacked in the axial direction. The stator core (20) has an annular yoke part (25) and teeth (23) extending from the yoke part to the inner peripheral side. The bobbin (30) covers the teeth. The coil (40) is wound around the bobbin. The pressing member (50) has a contact portion (54) that comes into contact with an axial end surface (25a) of the yoke portion.

Description

[0001] Cross-reference to related applications

[0002] This application is based on Japanese application No. 2022-080006 filed on May 16, 2022, and the contents thereof are cited herein. Technical Field

[0003] The present invention relates to a stator and a rotating electric machine. Background Art

[0004] For example, the stator described in Patent Document 1 has a stator core formed by a plurality of core sheets stacked in the axial direction. The stator core has an annular yoke and teeth extending from the yoke toward the inner circumference. Coils are wound around the teeth. The stator core is housed in a housing in such a way that the outer circumference of the yoke contacts the inner circumference of the housing.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-288424

[0008] In the stator as described above, there is a possibility that a portion of the core sheet that constitutes the yoke portion may be buckled due to, for example, a force applied to the yoke portion from the housing. Summary of the invention

[0009] An object of the present invention is to provide a stator and a rotating electrical machine capable of suppressing buckling of a core sheet.

[0010] In the first embodiment of the present invention, the stator comprises: a stator core, which is formed by a plurality of core materials stacked in the axial direction and has an annular yoke and teeth extending from the yoke to the inner circumference; a winding frame, which covers the teeth; a coil, which is wound on the winding frame; and a pressing member, which has an abutment portion abutting against the axial end face of the yoke.

[0011] In a second embodiment of the present invention, a rotating electric machine comprises a stator and a rotor opposite to the stator, wherein the stator comprises: a stator core formed by a plurality of core materials stacked in an axial direction and having an annular yoke and teeth extending from the yoke toward the inner circumference; a winding frame covering the teeth; a coil wound on the winding frame; and a pressing member having an abutment portion abutting against an axial end face of the yoke.

[0012] According to the above-described stator and rotating electrical machine, the pressing member having the contact portion that contacts the axial end surface of the yoke portion can suppress buckling of the portion constituting the yoke portion in the core sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present invention will become more apparent through the following detailed description with reference to the accompanying drawings. These drawings are:

[0014] Figure 1 It is a schematic diagram of a rotating electrical machine in the embodiment.

[0015] Figure 2 This is a perspective view partially showing a cross-section of a stator of this embodiment.

[0016] Figure 3 This is a schematic cross-sectional view of a stator of this embodiment.

[0017] Figure 4 This is a schematic side view of a stator of this type.

[0018] Figure 5 It is a schematic side view of a stator according to a modified example.

[0019] Figure 6 It is a schematic side view of a stator according to a modified example. DETAILED DESCRIPTION

[0020] Hereinafter, an embodiment of a stator and a rotating electrical machine will be described with reference to the accompanying drawings. In each of the drawings, for the sake of convenience of description, a part of the structure is sometimes exaggerated or simplified. In addition, the dimensional ratios of each part are sometimes different in each of the drawings.

[0021] like Figure 1 As shown, the rotating electric machine 10 includes a stator 11 and a rotor 12 opposite to the stator 11. The stator 11 is annular. The rotor 12 is arranged inside the stator 11. The rotor 12 has a rotating shaft 13. The rotor 12 is opposite to the stator 11 in the radial direction. The stator 11 is accommodated in a cylindrical housing 14. The stator 11 is accommodated in the housing 14 by, for example, shrink fit.

[0022] (Structure of stator 11)

[0023] like Figure 1 and Figure 2 As shown in FIG. 1 , the stator 11 includes a stator core 20, a winding frame 30, a coil 40, and a resin molded portion 50 as a pressing member. Figure 2 In FIG. 1 , a part of the resin mold portion 50 is shown in cross section.

[0024] The stator core 20 has a plurality of split cores 21 arranged in an annular shape along the circumferential direction of the stator 11. For example, 12 split cores 21 are provided. The stator core 20 has, for example, 12 split cores 21. Each split core 21 is made of, for example, a magnetic metal material. In the following description, the circumferential direction of the stator 11, the radial direction of the stator 11, and the axial direction of the stator 11 are sometimes referred to as "circumferential direction", "radial direction", and "axial direction", respectively.

[0025] Each split core 21 has a core back 22 and teeth 23 extending in the radial direction from the core back 22. The split cores 21 are arranged in the circumferential direction so that the core back 22 of each core is annular as a whole. Each tooth 23 extends in the radial direction.

[0026] In each core segment 21, the tooth 23 protrudes radially inward from the inner side surface of the core back portion 22, for example. The tip end of the tooth 23 faces the axis L1 of the stator 11. The base end of the tooth 23 is the radially outer end of the tooth 23.

[0027] like Figure 3 As shown, each split core 21 is formed of a plurality of core sheets 24 stacked in the axial direction. Each core sheet 24 is made of, for example, an electromagnetic steel sheet. Each core sheet 24 is fixed to each other by, for example, bonding.

[0028] like Figure 1 and Figure 2 As shown, in a state where each split core 21 is arranged in an annular shape along the circumferential direction, the core backs 22 of each split core 21 are arranged in an annular shape along the circumferential direction. Each core back 22 constitutes an annular yoke 25. Each core back 22 is in contact with the core backs 22 adjacent to each other on both sides in the circumferential direction. The radial outer side surface of each core back 22 forms the outer peripheral surface of the yoke 25. The outer peripheral surface of the yoke 25, that is, the radial outer side surface of each core back 22, is in contact with the inner peripheral surface of the housing 14. Each tooth 23 extends from the yoke 25 to the inner peripheral side.

[0029] like Figure 3 As shown, on each of the two axial sides of the stator core 20, the axial end face of each core back portion 22 forms the axial end face 25a of the yoke portion 25. The axial end face of each core back portion 22 is, for example, located on the same plane perpendicular to the axis L1. That is, the axial end faces 25a on both axial sides of the yoke portion 25 are in the shape of planes perpendicular to the axis L1.

[0030] A bobbin 30 is provided on each split core 21. For example, a plurality of bobbin 30 are provided corresponding to each of the plurality of split cores 21. The bobbin 30 has a tooth covering portion 31 covering the teeth 23. The coil 40 is wound around each tooth covering portion 31. That is, the tooth covering portion 31 of the bobbin 30 is interposed between the split core 21 and the coil 40. Thus, the bobbin 30 electrically insulates the split core 21 from the coil 40. In addition, each split core 21, the bobbin 30, and the coil 40 constitute an integral part.

[0031] The winding frame 30 is made of an insulator such as a synthetic resin. As a material of the winding frame 30, for example, an epoxy resin or the like can be used. The winding frame 30 is molded, for example, with respect to the split core 21. That is, it is formed integrally with the split core 21. Thus, the winding frame 30 and the split core 21 can be formed in a state of being in close contact.

[0032] In addition, as a structure different from the structure of the present embodiment, for example, when a winding frame manufactured separately from the split core 21 is subsequently mounted on the split core 21, there is a concern that a large gap will be generated between the split core 21 and the winding frame. In this regard, by molding the winding frame 30 with respect to the split core 21 as in the present embodiment, the gap between the split core 21 and the winding frame 30 can be eliminated or made extremely small.

[0033] (Structure of Resin Mold 50)

[0034] like Figure 2 As shown, the resin molded portion 50 covers the plurality of coils 40 together, for example. Figure 3 As shown, the coil 40 has a first end 41 as one axial end and a second end 42 as the other axial end. The resin molded portion 50 has a first covering portion 51 covering the first end 41 of the coil 40 and a second covering portion 52 covering the second end 42 of the coil 40. The first covering portion 51 covers the axial outer side of the first end 41 of the coil 40 and both radial sides of the first end 41. The second covering portion 52 covers the axial outer side of the second end 42 of the coil 40 and both radial sides of the second end 42.

[0035] like Figure 1 and Figure 2 As shown, the resin molded portion 50 has a connecting portion 53 that connects the first covering portion 51 and the second covering portion 52 through the space between the circumferentially adjacent teeth 23. The connecting portion 53 is filled between each of the plurality of teeth 23. The first covering portion 51 and the second covering portion 52 are connected to each other through the plurality of connecting portions 53.

[0036] In the stator 11, for example, an integral part including the split core 21, the bobbin 30, and the coil 40 is arranged in a ring shape. Then, for example, the coils 40 are electrically connected by a bus bar. Then, for example, the resin molded part 50 is molded so as to cover the coils 40, the bobbin 30, the bus bar, etc. together.

[0037] The resin molded portion 50 is formed of, for example, a resin having a thermal conductivity greater than that of the winding frame 30. As the material of the resin molded portion 50, for example, a material obtained by mixing alumina powder or the like in epoxy resin or unsaturated polyester resin can be used. The thermal conductivity of the winding frame 30 is set to, for example, 1.0 (W / m·K). In contrast, the thermal conductivity of the resin molded portion 50 is preferably set to, for example, 2.0 (W / m·K) or more.

[0038] In addition, the resin molded part 50 is preferably configured to have a large spring constant. If the spring constant of the resin molded part 50 is large, the volume of the resin molded part 50 required to suppress the buckling of the yoke 25 can be suppressed to a small value. As a result, the weight of the resin molded part 50 can be suppressed to a small value.

[0039] like Figure 2 and Figure 3 As shown, the first covering portion 51 and the second covering portion 52 each have abutting portions 54 that abut against the axial end face 25a of the yoke 25. The abutting portion 54 of the first covering portion 51 abuts against the axial end face 25a on one axial side in the axial direction. The abutting portion 54 of the second covering portion 52 abuts against the axial end face 25a on the other axial side in the axial direction. That is, the abutting portions 54 of the first covering portion 51 and the second covering portion 52 are respectively arranged in a manner of sandwiching the yoke 25 in the axial direction.

[0040] In this embodiment, the contact portion 54 is in a continuous ring shape along the circumferential direction. In addition, the contact portion 54 contacts each axial end surface 25a along the entire circumferential direction of the yoke 25. Figure 4 As shown, the contact portion 54 contacts the axial end surface 25a at the boundary portion 22x where the circumferentially adjacent core back portions 22 contact each other. Also, the contact portion 54 contacts the axial end surface 25a at the circumferential center portion 22y of each core back portion 22.

[0041] The operation of this embodiment will be described.

[0042] The yoke 25 of the stator core 20 receives a force directed radially inward from the housing 14. When the stator core 20 is assembled to the housing 14 by heat press fitting, the yoke 25 receives a force directed radially inward from the housing 14 more significantly. As a result, a force in a direction of approaching each other in the circumferential direction is generated in each core back portion 22 constituting the yoke 25. Therefore, if no countermeasures are taken, the core sheet 24 may be buckled in each core back portion 22 constituting the yoke 25 due to stress during heat press fitting, for example.

[0043] Therefore, in the present embodiment, the abutment portion 54 of the resin molded portion 50 abuts against the axial end face 25a of the yoke 25. Thus, when each core back portion 22 constituting the yoke 25 receives a force from the shell 14, the abutment portion 54 presses the axial end face 25a of the yoke 25, thereby suppressing the buckling of the portion constituting the core back portion 22 in the core sheet 24. In addition, the force to buckle the yoke 25 is applied in a direction extending toward both axial sides, and each abutment portion 54 of the first covering portion 51 and the second covering portion 52 bears the force. Here, the first covering portion 51 and the second covering portion 52 are connected by the connecting portion 53, so each abutment portion 54 of the first covering portion 51 and the second covering portion 52 can be used to appropriately bear the force to buckle the yoke 25.

[0044] In addition, the rotor 12 rotates by interacting with the rotating magnetic field, and the rotating magnetic field is generated in the stator 11 by energizing each coil 40. At this time, the coil 40 generates heat due to the energization. A part of the heat of the coil 40 is released to the outside through the resin molded part 50. As an example of a heat dissipation path, for example, a heat dissipation path from the coil 40 to the stator core 20 via the resin molded part 50. Moreover, the resin molded part 50 is formed of a material having a higher thermal conductivity than the thermal conductivity of the winding frame 30, so that the heat dissipation can be further improved.

[0045] The effects of this embodiment will be described.

[0046] (1) The stator 11 includes a resin molded portion 50 as a pressing member, and the resin molded portion 50 has an abutting portion 54 that abuts against the axial end surface 25a of the yoke 25. According to this structure, the resin molded portion 50 having the abutting portion 54 that abuts against the axial end surface 25a of the yoke 25 can suppress the buckling of the portion of the core material 24 that constitutes the yoke 25.

[0047] In addition, by using the abutment portion 54 to suppress the buckling of the core sheet 24, it is possible to eliminate the need for riveting for fixing the core sheets 24 to each other, or to reduce the number of riveted locations as much as possible. As a result, the iron loss caused by riveting in the flow of magnetic flux inside the core sheet 24 can be suppressed to a small level. As a result, it is possible to contribute to the high output of the rotating electrical machine 10.

[0048] In addition, by utilizing the abutment portion 54 to suppress the buckling of the core sheet 24, there is no need for an adhesive for mutually fixing each core sheet 24. That is, it is also possible to set a structure in which each core sheet 24 is not mutually fixed. In this case, since an adhesive for mutually bonding each core sheet 24 is not used, it is possible to set a structure with excellent heat resistance.

[0049] (2) The stator core 20 is composed of a plurality of split cores 21 arranged in the circumferential direction. Each of the plurality of split cores 21 has a core back portion 22 constituting a yoke portion 25 and teeth 23 extending from the core back portion 22. According to this structure, the yoke portion 25 is composed of the core back portions 22 of each split core 21. Therefore, each split core back portion 22 is more likely to buckle due to the force received from the housing 14. Therefore, the buckling suppression effect by the abutment portion 54 can be more significantly obtained.

[0050] (3) The abutment portion 54 abuts against the axial end surface 25a over the entire circumference of the yoke portion 25. According to this structure, in each core back portion 22, both the boundary portion 22x and the circumferential center portion 22y, which are prone to buckling, can be pressed by the abutment portion 54. Therefore, the buckling of the yoke portion 25 can be more appropriately suppressed by the abutment portion 54.

[0051] (4) The resin molded portion 50 covers the coil 40. The coil 40 has a first end portion 41 as one axial end portion and a second end portion 42 as the other axial end portion. The resin molded portion 50 has: a first covering portion 51, which covers the first end portion 41 of the coil 40; a second covering portion 52, which covers the second end portion 42 of the coil 40; and a connecting portion 53, which connects the first covering portion 51 and the second covering portion 52 through the coils 40 adjacent in the circumferential direction. In addition, the abutting portion 54 is included in the first covering portion 51 and the second covering portion 52, respectively. According to this structure, the abutting portion 54 of the first covering portion 51 and the abutting portion 54 of the second covering portion 52 sandwich the yoke 25 in the axial direction. In addition, the first covering portion 51 and the second covering portion 52 are connected to each other by the connecting portion 53. Therefore, on both sides of the axial direction of the yoke 25, the buckling of the yoke 25 can be more appropriately suppressed by the abutting portion 54.

[0052] (5) The stator core 20 has a plurality of teeth 23 arranged in the circumferential direction. A plurality of coils 40 are provided corresponding to the plurality of teeth 23. Furthermore, the resin molded portion 50 covers the plurality of coils 40 together. The heat dissipation of the coils 40 via the resin molded portion 50 can be improved. As a result, it can contribute to the high output of the rotating electrical machine 10.

[0053] (6) The resin mold portion 50 is formed of a material having a higher thermal conductivity than the bobbin 30. The heat dissipation of the coil 40 via the resin mold portion 50 can be further improved.

[0054] (Change Example)

[0055] The present embodiment can be implemented by being modified as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a range that does not technically contradict each other.

[0056] For example, Figure 5 or Figure 6 As shown, the contact portion 54 may be configured to partially contact the axial end surface 25a in the circumferential direction of the yoke 25. With such a configuration, the volume of the resin molded portion 50 can be reduced. As a result, the weight reduction of the stator 11 can be contributed.

[0057] exist Figure 5 In the structure shown, the abutment portion 54 abuts against the axial end face 25a at each boundary portion 22x where the core back portions 22 adjacent in the circumferential direction contact each other. According to such a structure, the resin molded portion 50 can be made lightweight and the buckling of the boundary portion 22x that is easily buckled in the core back portion 22 can be suppressed. In this case, the resin molded portion 50 including the abutment portion 54 can be distributed in the circumferential direction. In addition, it can also be as follows Figure 5As shown in the structure, the resin mold portion 50 does not cover the axially outer side of the coil 40 .

[0058] exist Figure 6 In the illustrated structure, the contact portion 54 contacts the axial end surface 25a at the circumferential center portion 22y of each core back portion 22. This structure can reduce the weight of the resin molded portion 50 and suppress buckling of the circumferential center portion 22y of the core back portion 22, which is easily buckled.

[0059] The resin mold portion 50 may be formed of a material having the same thermal conductivity as that of the bobbin 30 , or a material having a lower thermal conductivity than that of the bobbin 30 .

[0060] Each core sheet 24 may be fixed to each other by, for example, riveting. In addition, each core sheet 24 may be fixed to each other by, for example, riveting and bonding. In addition, each core sheet 24 may be fixed to each other by, for example, welding such as laser welding.

[0061] As temporary fixation until the resin molded portion 50 is formed, an adhesive may be used to fix the core sheets 24 to each other. In this case, the adhesive strength of the adhesive is sufficient as long as the adhesive strength until the resin molded portion 50 is formed, so there are few restrictions on the selection of the adhesive material.

[0062] The stator core 20 is not limited to the structure formed of a plurality of split cores 21 , but may be formed of an integral member. In such a structure, the contact portion 54 can also suppress buckling of the portion of the core sheet 24 that constitutes the yoke 25 .

[0063] The bobbin 30 of the above-described embodiment is molded with respect to the stator core 20 , but the present invention is not limited thereto. For example, a separately manufactured bobbin may be attached to the stator core 20 .

[0064] The numbers of the split cores 21 and the teeth 23 are not limited to those in the above-described embodiment, and can be appropriately changed according to the structure.

[0065] The rotating electrical machine 10 of the above embodiment is an inner rotor type rotating electrical machine in which the rotor 12 is arranged on the inner circumference side of the stator 11 , but may also be applied to an outer rotor type rotating electrical machine in which the rotor is arranged on the outer circumference side of the stator.

[0066] The present invention is described based on the embodiments, but it should be understood that the present invention is not limited to the embodiments and structures. The present invention also includes various modifications and variations within the equivalent range. In addition, various combinations, modes, and even other combinations and modes that only include one element, more than one element, or less than one element in them are also included in the scope and thought range of the present invention.

[0067] (Note)

[0068] The features of the present invention are shown as follows.

[0069] [1] A stator comprises: a stator core (20), which is formed by a plurality of core sheets (24) stacked in an axial direction and has an annular yoke (25) and teeth (23) extending from the yoke toward the inner circumference; a winding frame (30), which covers the teeth; a coil (40), which is wound on the winding frame; and a pressing member (50), which has an abutment portion (54) abutting against an axial end face (25a) of the yoke.

[0070] [2] The stator according to [1] above, wherein the stator core is composed of a plurality of split cores (21) arranged in a circumferential direction, and each of the plurality of split cores has a core back portion (22) constituting the yoke portion and the teeth extending from the core back portion.

[0071] [3] The stator according to [1] or [2] above, wherein the abutment portion abuts against the axial end surface over the entire circumference of the yoke portion.

[0072] [4] The stator according to [2] above, wherein the abutment portion partially abuts against the axial end surface in the circumferential direction of the yoke portion.

[0073] [5] The stator according to [4] above, wherein the abutment portion abuts against the axial end surface at a boundary portion (22x) where the core back portions adjacent to each other in the circumferential direction are in contact with each other.

[0074] [6] The stator according to the above [4], wherein the abutment portion abuts against the axial end surface at a circumferential center portion (22y) of the core back portion.

[0075] [7] A stator according to any one of [1] to [6] above, wherein the pressing component is a resin molded portion (50) covering the coil, the coil having one axial end portion (41) and the other axial end portion (42), and the resin molded portion having: a first covering portion (51), the first covering portion covering the one axial end portion of the coil; a second covering portion (52), the second covering portion covering the other axial end portion of the coil; and a connecting portion (53), the connecting portion connecting the first covering portion and the second covering portion, and the abutting portion is respectively included in the first covering portion and the second covering portion.

[0076] [8] The stator according to [7] above, wherein the stator core has a plurality of teeth arranged along the circumferential direction, a plurality of coils are provided corresponding to the plurality of teeth, respectively, and the resin mold portion covers the plurality of coils together.

[0077] [9] The stator according to [7] or [8] above, wherein the resin molded portion is formed of a material having a higher thermal conductivity than the bobbin.

[0078]

[10] A rotating electric machine (10) comprises a stator (11) and a rotor (12) opposite to the stator, wherein the stator comprises: a stator core (20) formed by a plurality of core sheets (24) stacked in an axial direction and having an annular yoke (25) and teeth (23) extending from the yoke toward the inner circumference; a winding frame (30) covering the teeth; a coil (40) wound on the winding frame; and a pressing member (50) having an abutment portion (54) abutting against an axial end face (25a) of the yoke.

Claims

1. A stator, characterized in that: have: A stator core (20) is formed by a plurality of core sheets (24) stacked in an axial direction and has an annular yoke (25) and teeth (23) extending from the yoke toward the inner circumference; a bobbin (30) covering the teeth; A coil (40) wound on the winding frame; as well as A pressing member (50) has an abutment portion (54) abutting against an axial end surface (25a) of the yoke portion.

2. The stator according to claim 1, characterized in that: The stator core is composed of a plurality of split cores (21) arranged in a circumferential direction. Each of the plurality of split cores includes a core back portion (22) constituting the yoke portion and the teeth extending from the core back portion.

3. The stator according to claim 1 or 2, characterized in that: The abutment portion abuts against the axial end surface over the entire circumference of the yoke portion.

4. The stator according to claim 2, characterized in that: The abutment portion partially abuts against the axial end surface in the circumferential direction of the yoke portion.

5. The stator according to claim 4, characterized in that: The abutment portion abuts against the axial end surface at a boundary portion (22x) where the core back portions adjacent to each other in the circumferential direction contact each other.

6. The stator according to claim 4, characterized in that: The abutment portion abuts against the axial end surface at a circumferential center portion (22y) of the core back portion.

7. The stator according to claim 1, characterized in that: The pressing member is a resin molded portion (50) covering the coil, The coil has one axial end (41) and another axial end (42). The resin molded portion comprises: a first covering portion (51) covering one axial end portion of the coil; a second covering portion (52) covering the other axial end portion of the coil; and a connecting portion (53) connecting the first covering portion and the second covering portion. The contact portion is included in the first covering portion and the second covering portion, respectively.

8. The stator according to claim 7, characterized in that: The stator core has a plurality of teeth arranged along the circumferential direction. A plurality of coils are provided corresponding to the plurality of teeth respectively. The resin mold covers the plurality of coils together.

9. The stator according to claim 7 or 8, characterized in that: The resin mold portion is formed of a material having a higher thermal conductivity than that of the bobbin.

10. A rotating electrical machine (10) comprising a stator (11) and a rotor (12) facing the stator, characterized in that: The stator has: A stator core (20) is formed by a plurality of core sheets (24) stacked in an axial direction and has an annular yoke (25) and teeth (23) extending from the yoke toward the inner circumference; a bobbin (30) covering the teeth; A coil (40) wound on the winding frame; as well as A pressing member (50) has an abutment portion (54) abutting against an axial end surface (25a) of the yoke portion.

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