Stator structure and electric motor

Abstract

The present invention suppresses leakage of filling resin. The disclosed stator structure (20) is provided with: a stator (30) having a stator core (31), an insulator (34), and a wound body (35); a bottomed cylindrical stator housing (40) that accommodates the stator (30); and a filling resin that fills a first space between the bottom of the stator frame (40) and the stator (30) and a second space between adjacent package bodies (35). The stator core (31) has at least one first passage (33d) and at least one second passage (33e) provided on the inner periphery of the first passage (33d). The first passage (33d) opens at each of one axial end and the other axial end of the stator core (31). The second passage (33e) opens at each of one axial end and the other axial end of the stator core (31).

Description

Technical Field

[0001] The present invention relates to a stator structure of a motor and a motor having the stator structure. Background Art

[0002] In the past, as a stator structure of an electric motor, there is known a stator structure comprising: a stator having a stator core including a plurality of teeth, an insulating member covering each tooth, and a winding body wound around the insulating member; a stator frame formed into a bottomed cylindrical shape with an opening and accommodating the stator; and a filling resin filled in the interior of the stator frame (for example, Patent Document 1). The stator frame of the stator structure of Patent Document 1 is provided with a self-closing valve at a resin injection port provided on its wall. When injecting the filling resin, a nozzle of a dispenser is inserted into the self-closing valve, and liquid filling resin is injected through the nozzle.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6561308 Summary of the invention

[0006] However, in the stator structure of Patent Document 1, although a self-closing valve is provided at the resin injection port, after the filling resin is injected, for example, when the nozzle is withdrawn from the resin injection port, the liquid filling resin may leak from the resin injection port. In such a situation, one of the purposes of the present invention is to suppress the leakage of the filling resin.

[0007] One scheme involved in the present invention relates to a stator structure. The stator structure comprises: a stator having a stator core including a back yoke and a plurality of teeth, an insulator covering each of the plurality of teeth, and a winding body wound on the insulator; a stator frame formed into a bottomed cylindrical shape with an opening and accommodating the stator; and a filling resin filled in a first space between the bottom of the stator frame and the stator and a second space between adjacent winding bodies. The stator core has at least one first passage and at least one second passage arranged at an inner circumference than the first passage, the first passage opening at one axial end and the other axial end of the stator core, respectively, and the second passage opening at one axial end and the other axial end of the stator core, respectively.

[0008] Another aspect of the present invention relates to an electric motor. The electric motor includes the above-mentioned stator structure.

[0009] According to the present invention, it is possible to suppress leakage of the filling resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a cross-sectional view schematically showing the stator structure according to the first embodiment.

[0011] Figure 2A It is a diagram for explaining the structure of the stator structure according to the first embodiment and is a perspective view schematically showing a stator core and a stator frame.

[0012] Figure 2B It is a diagram for explaining the structure of the stator structure according to the first embodiment and is a plan view schematically showing a segment core.

[0013] Figure 3A It is a plan view schematically showing the electric motor according to the first embodiment.

[0014] Figure 3B This is a front view schematically showing the electric motor according to the first embodiment.

[0015] Figure 4 This is a plan view schematically showing a segment core portion of a modified example of the first embodiment.

[0016] Figure 5 This is a plan view schematically showing a segment core portion according to the second embodiment.

[0017] Figure 6 This is a plan view schematically showing a segment core portion of a modified example of the second embodiment.

[0018] Figure 7 This is a plan view schematically showing a segment core portion according to the third embodiment. DETAILED DESCRIPTION

[0019] The following examples are used to illustrate the embodiments of the stator structure and the motor according to the present invention. However, the present invention is not limited to the examples described below. In the following description, specific numerical values ​​and materials are sometimes illustrated, but other numerical values ​​and materials may also be applied as long as the effects of the present invention can be obtained.

[0020] Hereinafter, an example of the stator structure and the motor involved in the present invention will be described with reference to the accompanying drawings. The components of the stator structure and the motor of the example described below that are not essential to the stator structure and the motor involved in the present invention may be omitted. It should be noted that the figures shown below are schematic diagrams and do not accurately reflect the shape and number of actual components. It should be noted that in the following figures ( Figure 1 to Figure 7 ), an XYZ orthogonal coordinate system is set. The details of the XYZ orthogonal coordinate system will be described later.

[0021] Implementation Method 1

[0022] Embodiment 1 of the present invention is described. The stator structure 20 of this embodiment can be applied to an inner rotor type three-phase synchronous motor, but is not limited thereto. First, the structure of the stator structure 20 and the motor 10 of this embodiment is described, and then the method for manufacturing the stator structure 20 of this embodiment is described.

[0023] -Structure of stator structure-

[0024] Figure 1 This is a cross-sectional view schematically showing the stator structure 20 according to the first embodiment. Figure 2A It is a diagram for explaining the structure of the stator structure 20 according to the first embodiment and is a perspective view schematically showing the stator core 31 and the stator frame 40 . Figure 2B 1 is a diagram for explaining the structure of the stator structure 20 of the first embodiment, and is a top view schematically showing the segment core 33. Figure 1 , Figure 2A as well as Figure 2B As shown, the stator structure 20 of the present embodiment includes a stator 30 , a stator frame 40 , a printed wiring board 50 , a connector 60 , and a filling resin 70 .

[0025] The stator 30 includes a stator core 31 including a back yoke portion 32 and a plurality of teeth 33b, an insulator 34 covering each of the teeth 33b, and a winding body 35 wound around the insulator 34. A second space S2 is formed between the winding bodies 35 connected to each other.

[0026] It should be noted that in the accompanying drawings, the XYZ orthogonal coordinate system is defined as follows. First, the Z axis is determined parallel to the central axis of the stator 30. Next, the X axis is determined perpendicular to the central axis of the stator 30 and parallel to the straight line passing through the center of the connector 60. Then, the Y axis is set perpendicular to the X axis and the Z axis. The positive direction of the X axis is the direction from the central axis of the stator 30 toward the connector 60. In addition, the positive direction of the Z axis is the direction opposite to the direction in which the stator 30 is inserted into the stator frame 40.

[0027] like Figure 2A As shown in FIG. 1 , the stator core 31 of the present embodiment is formed by combining a plurality of (12 in this example) segment cores 33. Figure 2B As shown in FIG. 1 , each segment core 33 has a yoke 33a, a tooth 33b, and a flange 33c. When a plurality of segment cores 33 are connected in a ring shape, a back yoke 32 is formed by a plurality of yokes 33a. Each segment core 33 is formed by stacking electromagnetic steel sheets. Figure 2A In the figure, only one insulating member 34 and only one winding body 35 are shown.

[0028] like Figure 2BAs shown in the figure, each segment core 33 has one first passage 33d and one second passage 33e. Therefore, the stator core 31 of this embodiment has a plurality of first passages 33d and a plurality of second passages 33e. The first passage 33d is a curved concave portion provided on the outer peripheral surface of each segment core 33 (or the outer peripheral surface of the stator core 31). The second passage 33e is provided in each segment core 33 at an inner circumference (or a position close to the tooth portion 33b) than the first passage 33d. The second passage 33e is a through hole, for example, a circular through hole, which penetrates each segment core 33 in the axial direction.

[0029] Each first passage 33 d is located closer to the opening 40 a ( Figure 1 The first passage 33d is opened at a position close to the opening 40a on the end face 70a (positive direction of the Z axis in the direction of the Z axis) and is opened in the first space S1 in the other direction. In this way, each first passage 33d is opened at one axial end of the stator core 31 and the other end in the Z axis direction. Each second passage 33e is opened at a position close to the opening 40a than the end face 70a of the stator frame 40 facing the filling resin 70 on one side and is opened in the first space S1 in the other direction. In this way, each second passage 33e is opened at one axial end and the other axial end of the stator core 31.

[0030] In each segment core portion 33, the distance D1 between the end of the tooth portion 33b in the circumferential direction of the stator core 31 (hereinafter, also referred to as the circumferential direction) and the second passage 33e is greater than half the dimension L1 of the base end of the tooth portion 33b in the circumferential direction (D1>L1 / 2). In addition, in each segment core portion 33, the distance D1 is greater than the dimension L2 of the yoke portion 33a in the radial direction of the stator core 31 (hereinafter, also referred to as the radial direction) (D1>L2). In addition, in each segment core portion 33, the distance D2 between the end of the tooth portion 33b in the circumferential direction and the first passage 33d is greater than half the dimension L1 (D2>L1 / 2). In addition, in each segment core portion 33, the distance D2 is greater than the dimension L2 (D2>L2). And, when viewed from the axial direction of the stator core 31, the second passage 33e is located on a straight line ( Figure 2B It should be noted that Figure 2B In the embodiment, the center line CL of the segment core 33 is parallel to the X-axis. That is, when describing the segment core 33, the segment core 33 whose center line CL is parallel to the X-axis is used as an example. Figure 4~Figure 7 The same is true in .

[0031] The shapes of the segment cores 33 are the same as each other. Therefore, the plurality of first passages 33d are arranged at equal intervals in the circumferential direction. In addition, the plurality of second passages 33e are arranged at equal intervals in the circumferential direction. In addition, in each segment core 33, when viewed from the axial direction of the stator core 31, the cross-sectional area of ​​the first passage 33d is larger than the cross-sectional area of ​​the second passage 33e. It should be noted that, here, the cross-sectional area of ​​the first passage 33d refers to the area of ​​the cut of the first passage 33d obtained when the segment core 33 is cut with a plane perpendicular to the axial direction of the stator core 31. In addition, the cross-sectional area of ​​the second passage 33e refers to the area of ​​the cut of the second passage 33e obtained when the segment core 33 is cut with a plane perpendicular to the axial direction of the stator core 31. Therefore, when viewed from the axial direction of the stator core 31, the sum of the cross-sectional areas of the plurality of first passages 33d, that is, the total area GA1, is larger than the sum of the cross-sectional areas of the plurality of second passages 33e, that is, the total area GA2. However, the total area GA1 may be smaller than the total area GA2 or may be equal to the total area GA2.

[0032] The stator frame 40 is formed in a bottomed cylindrical shape having an opening 40a, and accommodates the stator 30. A first space S1 is formed between the bottom of the stator frame 40 and the stator 30. A third space S3, which is a space corresponding to the first passage 33d, is formed between the inner circumferential surface of the stator frame 40 and the outer circumferential surface of the stator core 31. The stator frame 40 can be made of, for example, an aluminum alloy.

[0033] The printed wiring board 50 is electrically connected to the package 35. The printed wiring board 50 is arranged in the stator frame 40 closer to the opening 40 than the stator 30. The printed wiring board 50 may be formed in a ring shape (circular ring shape), a fan shape (circular arc shape), a C shape, etc. The printed wiring board 50 has a hollow portion in the center, and the output shaft 80 of the motor 10 (see later) is inserted into the hollow portion. Figure 3B ).

[0034] The connector 60 is electrically connected to the printed wiring board 50. The package 35 is electrically connected to the connector 60 via the printed wiring board 50. The connector 60 is connected to a power source for supplying power to the package 35. The connector 60 is arranged near the opening 40a of the stator frame 40.

[0035] The first space S1, the second space S2, and the third space S3 are filled with the filling resin 70. The filling resin 70 is, for example, epoxy resin, but is not limited thereto. The filling resin 70 includes a filler. The filler content of the filling resin 70 is, for example, 10 wt % or more and 50 wt % or less.

[0036] -Structure of the motor-

[0037] Figure 3A It is a plan view schematically showing the electric motor 10 according to the first embodiment. Figure 3B FIG. 2 is a front view schematically showing the motor 10 according to the first embodiment. Figure 3A as well as Figure 3B As shown, the motor 10 has various components such as a rotor, an output shaft 80, a pair of bearings, and a bracket in addition to the above-mentioned stator structure 20. It should be noted that the rotor, a pair of bearings, and the bracket are omitted from the figure. The rotor with the output shaft 80 is arranged in the internal space of the stator structure 20. Both ends of the output shaft 80 are supported by a pair of bearings so as to be rotatable. The outer ring side of one bearing is fixed to the receiving portion of the bracket. The outer ring side of the other bearing is fixed to the receiving portion at the bottom of the stator frame 40.

[0038] -Method for manufacturing stator structure-

[0039] Next, a method for manufacturing the above-mentioned stator structure 20 will be briefly described. The method for manufacturing the stator structure includes a preparation step, an insertion step, an injection step, and a curing step.

[0040] In the preparation step, the above-mentioned stator 30 and the above-mentioned stator frame 40 are prepared.

[0041] In the insertion step, the stator 30 is inserted into the stator frame 40. As a method of insertion, for example, shrink fitting, press fitting, etc. may be adopted.

[0042] In the injection process, the stator frame 40 is arranged with its opening 40a facing upward, and the liquid filling resin 70 is injected into the first space S1, the second space S2, and the third space S3 through each first passage 33d. At this time, at least a part of the air existing in each space (especially the first space S1) is pushed by the injected filling resin 7 and can be discharged to the outside through the second passage 33e.

[0043] In the curing step, the liquid filling resin 70 is cured while the stator frame 40 is arranged with the opening 40 a facing upward.

[0044] <<Variation of Implementation Example 1>>

[0045] A modification of the first embodiment of the present invention will be described. The stator structure 20 of this modification is different from the first embodiment in the number of second passages 33e. The differences from the first embodiment will be mainly described below.

[0046] Figure 4 FIG. 2 is a top view schematically showing a segmented core portion 33 of a modified example of Embodiment 1. Figure 4As shown in the figure, each segment core 33 has a plurality of (two in this example) second passages 33e. Each second passage 33e is provided at the inner circumference (or the tooth portion 33b side) of the first passage 33d in the segment core 33 having the second passage 33e. Each second passage 33e is a circular through hole that penetrates the segment core 33 having the second passage 33e in the axial direction. The two second passages 33e may also be arranged in line symmetry with respect to the center line CL. It should be noted that the number of the second passages 33e may also be three or more.

[0047] Implementation Method 2

[0048] Embodiment 2 of the present invention will be described. The stator structure 20 of this embodiment is different from that of the above-described embodiment 1 in the shape of the second passage 33e. Hereinafter, the differences from the above-described embodiment 1 will be mainly described.

[0049] Figure 5 FIG. 2 is a top view schematically showing the segment core 33 of Embodiment 2. Figure 5 As shown, the second passage 33e is rectangular, in particular, square. The four corners of the rectangle are sharp (or angular). The two sides of the inner circumference of the rectangle extend along the main magnetic path between the yoke 33a and the tooth 33b. In other words, the two sides of the inner circumference of the rectangle extend in a direction that intersects the direction in which the tooth 33b extends at a predetermined angle (45° in this example).

[0050] 《Variation of Implementation Example 2》

[0051] A modification of the second embodiment of the present invention will be described. The stator structure 20 of this modification is different from the second embodiment in the shape of the second passage 33e. The differences from the second embodiment will be mainly described below.

[0052] Figure 6 FIG. 2 is a top view schematically showing a segment core portion 33 of a modified example of Embodiment 2. Figure 6 As shown, the second passage 33e is substantially rectangular, in particular substantially square, and at least one corner (four corners in this example) of the substantially rectangular is rounded (or rounded).

[0053] Implementation Method 3

[0054] Embodiment 3 of the present invention will be described. The stator structure 20 of this embodiment is different from that of the above-described embodiment 1 in the structure of the first passage 33d. Hereinafter, the differences from the above-described embodiment 1 will be mainly described.

[0055] Figure 7FIG. 2 is a top view schematically showing the segmented core 33 of Embodiment 3. Figure 7 As shown, the first passage 33d is a circular through hole that axially penetrates the stator core 31. In the present embodiment, the cross-sectional area of ​​the first passage 33d and the cross-sectional area of ​​the second passage 33e are equal to each other when viewed from the axial direction of the stator core 31. However, the areas of the two passages may be different from each other.

[0056] "Summarize"

[0057] Hereinafter, the stator structure 20 and the electric motor 10 according to the present invention described above will be summarized.

[0058] (Stator structure)

[0059] The stator structure 20 according to the present invention includes a stator 30 , a stator frame 40 , and a filling resin 70 .

[0060] The stator 30 includes a stator core 31 including a back yoke portion 32 and a plurality of teeth 33b, an insulator 34 covering each of the teeth 33b, and a winding body 35 wound around the insulator 34. A second space S2 is formed between the winding bodies 35 connected to each other.

[0061] In the stator core 31, the back yoke portion 32 can be formed into a roughly cylindrical shape, and each tooth portion 33b can protrude radially inward from the back yoke portion 32. The back yoke portion 32 can be either a split type or an integrated type. The stator core 31 can be formed by stacking a plurality of electromagnetic steel plates. The insulating member 34 can be made of an insulating resin material. The winding body 35 can be made of an insulated wire with an insulating coating. The winding body 35 can be wound by a concentrated winding method or a distributed winding method.

[0062] The stator frame 40 is formed into a bottomed cylindrical shape having an opening 40a, and accommodates the stator 30. A first space S1 is formed between the bottom of the stator frame 40 and the stator 30. A third space S3 may be formed between the inner circumferential surface of the stator frame 40 and the outer circumferential surface of the stator core 31. The stator frame 40 may be made of a material having a high thermal conductivity, such as aluminum or an aluminum alloy. The thermal conductivity of the constituent material of the stator frame 40 may be higher than the thermal conductivity of the constituent material of the stator core 31.

[0063] The filling resin 70 is filled in the first space S1 and the second space S2. In the presence of a third space S3, the filling resin can also be filled in the third space S3. The filling resin 70 is generally a resin composition containing multiple components, and may contain epoxy resin, phenolic resin, polyester resin, acrylic resin, or polyurethane resin. The filling resin 70 may contain a filler. As a filler, inorganic particles are preferably used, for example, aluminum hydroxide can be used. The filler content of the filling resin 70 may be greater than 10% by weight and less than 50% by weight. The thermal conductivity of the filling resin 70 may be higher than the thermal conductivity of the constituent material of the insulating coating of the insulated wire constituting the winding body 35. The bending modulus of elasticity of the filling resin 70 may be lower than the bending modulus of elasticity of the constituent material of the stator frame 40.

[0064] The stator core 31 has at least one first passage 33d and at least one second passage 33e. The first passage 33d opens at one axial end and the other axial end of the stator core 31, respectively. The first passage 33d can connect one axial side of the stator core 31 with the other side when the filling resin 70 is filled. The second passage 33e is arranged at the inner periphery of the first passage 33d. The second passage 33e opens at one axial end and the other axial end of the stator core 31, respectively. The second passage 33e can connect one axial side of the stator core 31 with the other side when the filling resin 70 is filled. The shapes of the first passage 33d and the second passage 33e are not particularly limited. For example, each passage can extend along the axial direction of the stator core 31, or each passage can extend obliquely relative to the axial direction. The shapes of the openings of the first passage 33d and the second passage 33e are also not particularly limited. For example, they can be circular, elliptical, rectangular, polygonal, etc.

[0065] When the liquid filling resin 70 is injected using the first passage 33d and the second passage 33e, one of the two passages can be used as an injection path for the filling resin 70, and the other of the two passages can be used as an exhaust hole. For example, it is considered that each first passage 33d is used as an injection path for the filling resin 70, and on the other hand, each second passage 33e is used as an exhaust hole. Here, in the first passage 33d or the second passage 33e used as an injection path, at least a portion is filled with the filling resin 70. On the other hand, in the second passage 33e or the first passage 33d used as an exhaust hole, at least a portion may be filled with or not filled with the filling resin 70. However, from the viewpoint of improving the heat dissipation of the stator structure 20, it is preferable to fill at least a portion of the latter with the filling resin 70.

[0066] The liquid filling resin 70 is injected in a state where the stator core 31 is accommodated in the stator frame 40. For example, the liquid filling resin 70 can be injected from above through each first passage 33d in a state where the stator frame 40 is arranged with its opening 40a facing upward and the stator core 31 is arranged with its axial direction along the vertical direction. In this case, for example, the liquid filling resin 70 can be first filled into the first space S1 through each first passage 33d, and then filled into the second space S2. During this filling, the air present in each space (especially the first space S1) can be discharged upward through each second passage 33e, so the filling rate of the filling resin 70 can be increased. In addition, if such a filling method is used, the liquid filling resin 70 is not easy to leak. This is because the liquid level of the filling resin 70 when the filling of the liquid filling resin 70 is completed is lower than the height of the entrance of the first passage 33d (or the second passage 33e) as the inlet. The liquid filling resin 70 may be cured in a state where the stator core 31 is arranged with its axial direction along the vertical direction.

[0067] The first passage 33d may be a recessed portion provided on the outer peripheral surface of the stator core 31 or a through hole axially penetrating the stator core 31. The second passage 33e may be a through hole axially penetrating the stator core 31. Such first passage 33d and second passage 33e can be easily formed.

[0068] The distance D1 (e.g., the shortest distance) between the end of the tooth portion 33b in the circumferential direction of the stator core 31 and the second passage 33e may be greater than half the size of the base end of the tooth portion 33b in the circumferential direction. The second passage 33e may be provided at a location closer to the periphery than the base end of the tooth portion 33b (or the back yoke portion 32). With this structure, a sufficient distance can be ensured between the end of the tooth portion 33b in the circumferential direction and the second passage 33e, thereby suppressing the magnetic resistance in the magnetic circuit connecting the back yoke portion 32 and the tooth portion 33b.

[0069] The distance (for example, the shortest distance) between the end of the tooth portion in the circumferential direction of the stator core and the second path can be greater than the size of the back yoke portion in the radial direction of the stator core. The second path can be arranged at the outer periphery (or the back yoke portion) relative to the base end of the tooth portion. With this structure, a sufficient distance can be ensured between the end of the tooth portion in the circumferential direction and the second path, thereby suppressing the magnetic resistance in the magnetic circuit connecting the back yoke portion and the tooth portion.

[0070] The distance D2 (e.g., the shortest distance) between the end of the tooth portion 33b in the circumferential direction of the stator core 31 and the first passage 33d may be greater than half the size of the base end of the tooth portion 33b in the circumferential direction. The first passage 33d may be provided at a location closer to the periphery than the base end of the tooth portion 33b (or the back yoke portion 32). With this structure, a sufficient distance can be ensured between the end of the tooth portion 33b in the circumferential direction and the first passage 33d, thereby suppressing the magnetic resistance in the magnetic circuit connecting the back yoke portion 32 and the tooth portion 33b.

[0071] The distance D2 between the end of the tooth portion 33b in the circumferential direction of the stator core 31 and the first passage 33 may be greater than the size of the back yoke portion 32 in the radial direction of the stator core 31. The first passage 33d may be provided at the outer periphery (or the back yoke portion 32) than the base end of the tooth portion 33b. With this structure, a sufficient distance can be ensured between the end of the tooth portion 33b in the circumferential direction and the first passage 33d, thereby suppressing the magnetic resistance in the magnetic circuit connecting the back yoke portion 32 and the tooth portion 33b.

[0072] When the stator core 31 is viewed from the axial direction, the second passage 33e can be located on a straight line passing through the center of the stator core 31 and the center of the tooth 33b. With this structure, the distance between one end of the tooth 33b in the circumferential direction of the stator core 31 and the second passage 33e, and the distance between the other end of the tooth 33b in the circumferential direction and the second passage 33e are substantially equal, so that a large magnetic resistance is not easily formed near the tooth 33b. It should be noted that the so-called "the second passage 33e is located on a straight line passing through the two centers" includes not only the case where the center of the second passage 33e is located on the straight line when viewed from the axial direction of the stator core 31, but also the case where at least a portion of the second passage 33e coincides with the straight line.

[0073] A plurality of first passages 33d may be provided at intervals along the circumferential direction of the stator core 31. The plurality of first passages 33d may be used as an injection path for the liquid filling resin 70. With this structure, the filling resin 70 is injected from a plurality of locations in the circumferential direction of the stator core 31, so that the filling rate of the filling resin 70 can be further improved.

[0074] The plurality of first passages 33d may be arranged at equal intervals in the circumferential direction of the stator core 31. This configuration can impart symmetry to the magnetic circuit of the stator core 31. Specifically, the magnetic circuit of the stator core 31 can be made nearly rotationally symmetrical with respect to the center of the stator core 31.

[0075] A plurality of second passages 33e may be provided at intervals along the circumferential direction of the stator core 31. The plurality of second passages 33e may be used as exhaust holes when injecting the filling resin 70. With this structure, air is exhausted from a plurality of locations in the circumferential direction of the stator core 31, so that the filling rate of the filling resin 70 can be further improved.

[0076] The plurality of second passages 33e may be arranged at equal intervals in the circumferential direction of the stator core 31. This configuration can impart symmetry to the magnetic circuit of the stator core 31. Specifically, the magnetic circuit of the stator core 31 can be made nearly rotationally symmetrical with respect to the center of the stator core 31.

[0077] The one with the larger total area when viewed from the axial direction of the stator core 31, among the at least one first passage 33d and the at least one second passage 33e, can be used as an injection path for the liquid filling resin 70. The one with the smaller total area when viewed from the axial direction of the stator core 31 can be used as an exhaust hole when injecting the filling resin 70. With this structure, the filling rate of the filling resin 70 can be further improved.

[0078] In the former case, the positions (angular positions) of the first passages 33d and the second passages 33e in the circumferential direction of the stator core 31 may be the same or different.

[0079] The second passage 33e may be circular, elliptical, or polygonal in shape when viewed from the axial direction of the stator core 31. When the second passage 33e is polygonal, at least one side of the polygon preferably extends along the main magnetic path in order to suppress the magnetic resistance of the main magnetic path of the stator core 31.

[0080] (Electric Motor)

[0081] The motor 10 involved in the present invention has any of the above-mentioned stator structures 20. The motor 10 may also have components such as a rotor, an output shaft 80 (rotating shaft), a pair of bearings, and a bracket. The rotor having the output shaft 80 can be arranged in the internal space of the stator structure 20. Both ends of the output shaft 80 can be supported by a pair of bearings so as to be rotatable. The outer ring side of one bearing can be fixed to the receiving portion of the bracket. The outer ring side of the other bearing can be fixed to the receiving portion at the bottom of the stator frame 40.

[0082] As described above, according to the present invention, leakage of the filling resin 70 can be suppressed when filling the liquid filling resin 70. Furthermore, according to the present invention, deterioration of the appearance of the motor 10 due to leakage of the filling resin 70 can be avoided.

[0083] Postscript

[0084] The following technical solutions are disclosed through the description of the above embodiments.

[0085] (Technique 1)

[0086] A stator structure, wherein:

[0087] The stator structure comprises:

[0088] A stator having a stator core including a back yoke portion and a plurality of teeth, an insulating member covering each of the teeth, and a winding body wound around the insulating member;

[0089] a stator frame formed in a bottomed cylindrical shape with an opening and accommodating the stator; and

[0090] A filling resin is filled in a first space between the bottom of the stator frame and the stator and a second space between adjacent winding bodies.

[0091] The stator core has at least one first passage and at least one second passage provided at an inner circumference than the first passage.

[0092] The first passage opens at one axial end and the other axial end of the stator core respectively.

[0093] The second passage opens at one axial end and the other axial end of the stator core, respectively.

[0094] (Technique 2)

[0095] Based on the stator structure described in technology 1,

[0096] The first passage is a recessed portion provided on the outer peripheral surface of the stator core, or a through hole penetrating the stator core in the axial direction thereof.

[0097] The second passage is a through hole that penetrates the stator core in the axial direction.

[0098] (Technique 3)

[0099] Based on the stator structure described in technology 1 or 2,

[0100] A distance between an end portion of the tooth portion in the circumferential direction of the stator core and the second passage is larger than a half of a size of a base end portion of the tooth portion in the circumferential direction.

[0101] (Technique 4)

[0102] Based on the stator structure described in any one of technologies 1 to 3,

[0103] A distance between an end of the teeth portion in a circumferential direction of the stator core and the second passage is larger than a dimension of the back yoke portion in a radial direction of the stator core.

[0104] (Technique 5)

[0105] Based on the stator structure described in any one of technologies 1 to 4,

[0106] A distance between an end portion of the tooth portion in the circumferential direction of the stator core and the first passage is larger than a half of a size of a base end portion of the tooth portion in the circumferential direction.

[0107] (Technique 6)

[0108] Based on the stator structure described in any one of technologies 1 to 5,

[0109] A distance between an end of the teeth portion in a circumferential direction of the stator core and the first passage is greater than a dimension of the back yoke portion in a radial direction of the stator core.

[0110] (Technique 7)

[0111] Based on the stator structure described in any one of technologies 1 to 6,

[0112] The second passage is located on a straight line passing through a center of the stator core and a center of the tooth portion when viewed in an axial direction of the stator core.

[0113] (Technique 8)

[0114] Based on the stator structure described in any one of technologies 1 to 7, wherein:

[0115] A plurality of the first passages are provided at intervals along the circumferential direction of the stator core.

[0116] (Technique 9)

[0117] Based on the stator structure described in technology 8,

[0118] The plurality of first passages are arranged at equal intervals in the circumferential direction.

[0119] (Technology 10)

[0120] Based on the stator structure described in any one of technologies 1 to 9,

[0121] A plurality of the first passages are provided at intervals along the circumferential direction of the stator core.

[0122] (Technology 11)

[0123] Based on the stator structure described in technology 10,

[0124] The plurality of second passages are arranged at equal intervals in the circumferential direction.

[0125] (Technology 12)

[0126] An electric motor comprises a stator structure as described in any one of techniques 1 to 11.

[0127] Industrial Applicability

[0128] The present invention can be used in a stator structure and a motor.

[0129] Description of Reference Numerals

[0130] 10 electric motor; 20 stator structure; 30 stator; 31 stator core; 32 back yoke; 33 segmented core; 33a yoke; 33b tooth; 33c flange; 33d first passage; 33e second passage; 34 insulating member; 35 package; 40 stator frame; 40a opening; 50 printed wiring board; 60 connector; 70 filling resin; 70a end face; 80 output shaft; CL center line; D1 distance; D2 distance; L1 dimension; L2 dimension; S1 first space; S2 second space; S3 third space.

Claims

1. A stator structure, wherein: The stator structure comprises: A stator having a stator core including a back yoke portion and a plurality of teeth portions, an insulator covering each of the plurality of teeth portions, and a winding body wound around the insulator; a stator frame, which is formed into a bottomed cylindrical shape with an opening and accommodates the stator; as well as A filling resin is filled in a first space between the bottom of the stator frame and the stator and a second space between adjacent winding bodies. The stator core has at least one first passage and at least one second passage provided at an inner circumference than the first passage. The first passage opens at one axial end and the other axial end of the stator core respectively. The second passage opens at the one axial end and the other axial end of the stator core, respectively.

2. The stator structure according to claim 1, wherein: The first passage is a recessed portion provided on the outer peripheral surface of the stator core, or a through hole penetrating the stator core in the axial direction thereof. The second passage is a through hole that penetrates the stator core in the axial direction.

3. The stator structure according to claim 1, wherein: A distance between an end portion of the tooth portion in the circumferential direction of the stator core and the second passage is larger than a half of a size of a base end portion of the tooth portion in the circumferential direction.

4. The stator structure according to claim 1, wherein: A distance between an end of the teeth portion in a circumferential direction of the stator core and the second passage is larger than a dimension of the back yoke portion in a radial direction of the stator core.

5. The stator structure according to claim 1, wherein: A distance between an end portion of the tooth portion in the circumferential direction of the stator core and the first passage is larger than a half of a size of a base end portion of the tooth portion in the circumferential direction.

6. The stator structure according to claim 1, wherein: A distance between an end of the teeth portion in a circumferential direction of the stator core and the first passage is greater than a dimension of the back yoke portion in a radial direction of the stator core.

7. The stator structure according to claim 1, wherein: The second passage is located on a straight line passing through a center of the stator core and a center of the tooth portion when viewed in an axial direction of the stator core.

8. The stator structure according to claim 1, wherein: A plurality of the first passages are provided at intervals along the circumferential direction of the stator core.

9. The stator structure according to claim 8, wherein: The plurality of first passages are arranged at equal intervals in the circumferential direction.

10. The stator structure according to claim 1, wherein: A plurality of second passages are provided at intervals along the circumferential direction of the stator core.

11. The stator structure according to claim 10, wherein: The plurality of second passages are arranged at equal intervals in the circumferential direction.

12. An electric motor, wherein: The electric motor includes the stator structure according to any one of claims 1 to 11.

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