Motor

Abstract

The present invention suppresses the generation of foreign matter during motor manufacturing. The disclosed motor (10) is provided with: a stator (20) having a plurality of divided iron cores (21) each including a core member (22) and an insulator (25) and connected in a ring shape; and an annular frame (40) into which the stator (20) is inserted by hot charging or press-fitting. The stator (20) is provided with at least one first portion (26) having a hardness lower than that of the frame (40). The distance (R1) from the outermost peripheral portion (26a) of the first portion (26) to the axial center of the stator (20) is equal to or greater than the distance (R2) from the outermost peripheral portion (23) of the core member (22) to the axial center of the stator (20). The first portion (26) is disposed at least in front of the core member (22) in an insertion direction of the stator (20) with respect to the frame (40).

Description

Technical Field

[0001] The present disclosure relates to a motor. Background Art

[0002] Conventionally, there is known a motor having a stator core fixed to a core holder by shrink fitting (for example, Patent Document 1). When manufacturing the motor of Patent Document 1, the core holder is expanded by heating, the stator core is inserted into the expanded core holder, and then the stator core is fixed by the contracted core holder.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-82552 Summary of the invention

[0006] However, in the above-mentioned hot-fitting insertion process, due to the contact between the core holder and the stator core, which are respectively made of metal, one or both of them may be ground and foreign matter may be generated. When the generated foreign matter is sandwiched between the core holder and the stator core, the inner diameter accuracy of the stator core may be reduced or the cogging torque of the motor may be increased. Under such circumstances, one of the purposes of the present disclosure is to suppress the generation of foreign matter during motor manufacturing.

[0007] One scheme involved in the present disclosure relates to a motor. The motor includes: a stator having a plurality of split iron cores each including a core member and an insulator and connected in an annular shape; and an annular frame into which the stator is inserted by shrink fitting or press fitting, the stator having at least one first portion having a lower hardness than the frame, a distance (R1) from the outermost peripheral portion of the first portion to the axial center of the stator being greater than a distance (R2) from the outermost peripheral portion of the core member to the axial center of the stator, and the first portion being arranged at least in front of the core member in the insertion direction of the stator relative to the frame.

[0008] According to the present disclosure, generation of foreign matter during motor manufacturing can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a perspective view showing the motor according to the first embodiment.

[0010] Figure 2 This is a perspective view showing a split core included in the motor according to the first embodiment.

[0011] Figure 3 The figure shows the middle stage of inserting the stator into the frame in the first embodiment. Figure 1 Cross-sectional view along line III-III.

[0012] Figure 4 Yes Figure 3 A cross-sectional view showing an enlarged view of a main part.

[0013] Figure 5 This is a perspective view showing a motor according to the second embodiment.

[0014] Figure 6 This is a perspective view showing a split iron core included in the motor according to the second embodiment.

[0015] Figure 7 The main part of the middle stage of inserting the stator into the frame in the second embodiment is enlarged and shown along the Figure 5 A cross-sectional view taken along line VII-VII.

[0016] Figure 8 It is a perspective view showing a motor according to the third embodiment.

[0017] Fig. 9 This is a perspective view showing the split cores according to the third embodiment (and the fourth embodiment).

[0018] Fig.10 The main part of the middle stage of inserting the stator into the frame in the third embodiment is enlarged and shown along the Figure 8 Cross-sectional view of line XX.

[0019] Fig.11 It is a perspective view showing a motor according to a fourth embodiment.

[0020] Fig.12 The main part of the stator is enlarged and shown in the middle of the stator insertion into the frame in the fourth embodiment. Fig.11 A cross-sectional view taken along line XII-XII.

[0021] Fig.13 It is a cross-sectional view showing the outline of the motor of the present disclosure. DETAILED DESCRIPTION

[0022] The following examples illustrate the implementation of the motor involved in the present disclosure. However, the present disclosure is not limited to the examples described below. In the following description, specific values ​​and materials are sometimes illustrated, but other values ​​and materials may also be applied as long as the effects of the present disclosure can be obtained.

[0023] The motor involved in the present disclosure is, for example, an inner rotor type three-phase synchronous motor, but is not limited thereto. The motor has a stator and a frame. The motor may also have a rotor. However, the present disclosure also treats a motor structure having a stator and a frame without a rotor as a motor, and also includes such a structure.

[0024] The stator has a plurality of split cores connected in a ring shape. Each split core includes a core member and an insulating member. The plurality of split cores may not be welded to each other. The plurality of split cores may be connected to each other by engaging the male and female parts of each of them. The core member may be made of a magnetic material (e.g., a laminated steel plate or a pressed powder magnetic core). The insulating member may be made of an insulating material. The insulating material may be a general-purpose resin such as polyethylene terephthalate (PET), an insulating resin such as an engineering plastic, etc. A coil may be wound around the core member through an insulating member. The number of split cores of the stator may be set arbitrarily, for example, it may be 12.

[0025] The frame is annular (or cylindrical) and has the stator inserted therein by shrink fitting or press fitting. The frame may be made of a metal material. In particular, the frame may be made of a metal material (eg, aluminum or an aluminum alloy) having a lower hardness than the core member.

[0026] In this specification, "hardness" means Brinell hardness, which can be measured by a method in accordance with JIS Z 2243.

[0027] The stator has at least one first portion having a lower hardness than the frame. The distance R1 from the outermost periphery of the first portion to the axis of the stator is greater than the distance R2 from the outermost periphery of the core member to the axis of the stator (R1≥R2). The distance R1 may be equal to the distance R2 or greater than the distance R2. In other words, in the radial direction of the stator, the outermost periphery of the first portion is not located closer to the inner circumference than the outermost periphery of the core member. The first portion is at least arranged in front of the core member in the insertion direction of the stator relative to the frame. In the insertion direction, the first portion may also be arranged behind the core member, or may not be arranged behind the core member.

[0028] When a stator having such a first portion is inserted into a frame, the outermost circumference of the core member (or the corner in front of the insertion direction) is suppressed from contacting the frame. This is because, when the stator is inserted into the frame, the outermost circumference of the first portion can contact the frame before the core member, but the outermost circumference of the core member is hidden behind the insertion direction of the first portion. Or, when the stator is inserted into the frame, the radial displacement of the stator is restricted so that the outermost circumference of the core member does not contact the frame due to the outermost circumference of the first portion inserted before the core member. In the above sense, the first portion can be said to be a portion that suppresses the contact between the core member and the frame when the stator is inserted into the frame. Since the contact between the outermost circumference of the core member and the frame is suppressed, the generation of foreign matter caused by grinding of one or both of the two materials, which are usually made of metal materials, can be suppressed.

[0029] The first portion may be formed integrally with the insulating member. According to this structure, the motor of the present disclosure can be realized by only changing the design of the insulating member.

[0030] The stator may further include an insulating cap disposed between the insulating member and the frame. The first portion may be formed integrally with the insulating cap. The insulating cap may electrically insulate the coil wound on the insulating member from the frame. The insulating cap may be made of an insulating material (eg, PET).

[0031] The stator may also include a ring disposed on the outer circumference of the insulating member. The first portion may be formed integrally with the ring. The ring may be made of an insulating material (e.g., PET). According to this structure, the generation of foreign matter during manufacturing can be suppressed by adding such a ring without changing the basic design of the motor.

[0032] A plurality of first portions may be intermittently provided in the circumferential direction of the stator. For example, a plurality of first portions (for example, two) may be provided for each split iron core. Such a plurality of first portions function as guides to prevent the corners of the core member from coming into contact with the frame when the stator is inserted into the frame. On the other hand, after insertion, they are easily flattened radially inward by the pressing force from the frame. Therefore, in the completed motor, it is not easy for the outermost peripheral portion of the first portion to protrude significantly radially outward than the outermost peripheral portion of the core member, and a situation in which the dimensional accuracy is reduced due to the first portion can be avoided. Among them, the first portion may also be provided continuously with only one within the entire circumference of the stator.

[0033] The difference between the distance R1 and the distance R2 may be greater than 0 mm and less than 0.1 mm. If the difference between the two distances is greater than 0 mm, the first portion can sufficiently suppress the contact between the corner of the core member and the frame when the stator is inserted into the frame. If the difference between the two distances is less than 0.1 mm, after insertion, the outermost peripheral portion of the first portion is flattened radially inward by the pressing force from the frame, thereby fully avoiding a reduction in dimensional accuracy due to the first portion in the completed motor.

[0034] As described above, according to the present disclosure, the frame is not easily ground during shrink fitting or press fitting, thereby suppressing the generation of foreign matter during motor manufacturing. In addition, according to the present disclosure, the inner diameter accuracy of the stator is improved due to the suppression of foreign matter generation, thereby suppressing the cogging torque of the motor.

[0035] Hereinafter, an example of a motor involved in the present disclosure will be described in detail with reference to the accompanying drawings. The above-mentioned components can be applied to the components of the motor of the example described below. The components of the motor of the example described below can be changed based on the above-mentioned description. In addition, the matters described below can also be applied to the above-mentioned embodiment. The components of the motor of the example described below that are not necessary for the motor involved in the present disclosure can also 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. In addition, "above" and "below" indicate relative above and below, and do not necessarily only indicate vertically above and vertically below.

[0036] Implementation Method 1

[0037] Embodiment 1 of the present disclosure will be described. The motor 10 of the present embodiment is an inner rotor type three-phase synchronous motor. Figure 1 This is a perspective view showing the motor 10 according to the first embodiment. Figure 2 This is a perspective view showing the split core 21 of the stator 20 included in the motor 10 according to the first embodiment. Figure 3 1 is a diagram showing a midway stage of inserting the stator 20 into the frame 40 in the first embodiment, and is a diagram showing a midway stage of inserting the stator 20 into the frame 40 in the first embodiment. Figure 1 Cross-sectional view along line III-III. Figure 4 Yes Figure 3 The main part is enlarged and shown in a cross-sectional view. Fig.13 FIG. 1 is a cross-sectional view showing the outline of the motor 10 according to the first embodiment. Figure 1 In the embodiment, the rotor 50 and the frame 40 are omitted. Figure 1~Figure 4 as well as Fig.13 As shown, the motor 10 includes a stator 20 , a frame 40 , and a rotor 50 .

[0038] The stator 20 has a plurality of (12 in this example) split cores 21 connected in a ring shape. Each split core 21 includes a core member 22 and an insulating member 25. The core member 22 is composed of laminated steel plates. A first recess 23a is formed on a first outer surface 23 of the core member 22 (i.e., a surface extending in the circumferential direction of the stator 20). The core member 22 has a tooth portion 24 opposite to the rotor. The insulating member 25 is composed of an insulating resin. The insulating member 25 is arranged in a manner that surrounds the tooth portion 24. A coil 29 is wound around the tooth portion 24 in a concentrated winding manner through the insulating member 25. The stator 20 generates a rotating magnetic field for rotating the rotor due to the flow of current through the coil 29. The first outer surface 23 of the core member 22 is an example of the outermost peripheral portion of the core member.

[0039] The frame 40 is annular, and the stator 20 is inserted into the frame 40 by shrink fitting. However, the stator 20 may be inserted into the frame 40 by press fitting. The frame 40 is made of aluminum alloy.

[0040] The stator 20 is provided with a plurality of (48 in this example) protrusions 26 integrally formed on the insulating member 25. Four protrusions 26 are provided on each split core 21, but the number and arrangement of the protrusions 26 are not limited thereto. The protrusion 26a of the protrusion 26 is formed into a shape having a curved surface and a rounded corner, but the shape of the protrusion 26a can be arbitrarily changed. The hardness of the protrusion 26 made of insulating resin is lower than the hardness of the frame 40 made of aluminum alloy. Two protrusions 26 are provided on both sides of the core member 22 in the axial direction of the stator 20 (or the insertion direction of the stator 20 relative to the frame 40). The plurality of protrusions 26 are intermittently provided in the circumferential direction of the stator 20. The angle between the protrusions 26 adjacent in the circumferential direction of the stator 20 (i.e., the angle formed by two straight lines passing through the axis O of the stator 20 and the protrusions 26a of the adjacent protrusions 26) can be, for example, greater than 10° and less than 25°. The protrusion 26 is an example of the first part. The protruding end 26a of the convex portion 26 is an example of the outermost peripheral portion of the first portion.

[0041] The distance R1 from the protruding end 26a of the convex portion 26 to the axis O of the stator 20 (i.e., the radius R1 of a circle centered on the axis O and circumscribed to the protruding end 26a of the convex portion 26) is greater than or equal to the distance R2 from the outermost circumference of the core member 22 to the axis O of the stator 20 (i.e., the radius R2 of a circle centered on the axis O and circumscribed to the first outer surface 23 of the core member 22) (R1 ≥ R2). The difference between the distance R1 and the distance R2 is greater than or equal to 0 mm and less than or equal to 0.1 mm. By using such a convex portion 26, as Figure 3 as well as Figure 4 As shown, when the stator 20 is inserted into the frame 40, the core member 22 is inserted in the front direction ( Figure 3 as well as Figure 4 The corners of the lower portion of the frame 40 are prevented from contacting the frame 40. This is because, in particular, Figure 4 As shown, the corner portion is hidden behind the insertion direction of the protrusion 26 ( Figure 4 in the upper part).

[0042] Implementation Method 2

[0043] Embodiment 2 of the present disclosure will be described. The structure of the insulating member 25 of the motor 10 of this embodiment is different from that of the above-mentioned Embodiment 1. Hereinafter, the points different from the above-mentioned Embodiment 1 will be mainly described.

[0044] Figure 5 It is a perspective view showing the motor 10 according to the second embodiment. Figure 6 It is a perspective view showing the split core 21 of the stator 20 included in the motor 10 according to the second embodiment. Figure 7 The main part of the second embodiment is enlarged and shown in the middle of inserting the stator 20 into the frame. Figure 5 It should be noted that the motor 10 of the second embodiment is similar to the motor 10 of the first embodiment, and its cross-sectional view is the same as that of the motor 10 of the first embodiment. Fig.13 It should be noted that in Figure 5 The rotor 50 and the frame 40 are omitted.

[0045] like Figure 5~Figure 7 As shown, in this embodiment, the insulating member 25 has a second outer surface 27 (i.e., a surface extending in the circumferential direction of the stator 20) located radially outward from the first outer surface 23 of the core member 22. On the second outer surface 27, a second recess 27a is formed in the axial direction of the stator 20 so as to be aligned with the first recess 23a. The second outer surface 27 and the vicinity thereof in the insulating member 25 are an example of the first portion. The second outer surface 27 of the insulating member 25 is an example of the outermost peripheral portion of the first portion.

[0046] The distance R1 from the second outer surface 27 of the insulating member 25 to the axis O of the stator 20 (i.e., the radius R1 of a circle centered on the axis O and circumscribed to the second outer surface 27) is greater than the distance R2 from the outermost circumference of the core member 22 to the axis O of the stator 20 (i.e., the radius R2 of a circle centered on the axis O and circumscribed to the first outer surface 23 of the core member 22). According to such a second outer surface 27 and its vicinity, as Figure 7 As shown, when the stator 20 is inserted into the frame 40, the core member 22 is inserted in the front direction ( Figure 7 The corner portion of the second outer surface 27 and the vicinity thereof is prevented from contacting the frame 40. This is because, as shown in the figure, the corner portion is hidden behind the second outer surface 27 and the vicinity thereof in the insertion direction ( Figure 7 in the upper part).

[0047] Implementation Method 3

[0048] Embodiment 3 of the present disclosure will be described. The motor 10 of this embodiment is different from the above-described embodiment 1 in that the stator 20 includes an insulating cap 31. Hereinafter, the differences from the above-described embodiment 1 will be mainly described.

[0049] Figure 8 It is a perspective view showing the motor 10 according to the third embodiment. Fig. 9 It is a perspective view showing the split core 21 of the stator 20 included in the motor 10 according to the third embodiment. Fig.10 The main part of the third embodiment is enlarged and shown in the middle of inserting the stator 20 into the frame 40. Figure 8 It should be noted that the outline of the motor 10 of the third embodiment is the same as that of the motor 10 of the first embodiment, and its cross-sectional view is the same as that of the motor 10 of the first embodiment. Fig.13It should be noted that in Figure 8 The rotor 50 and the frame 40 are omitted.

[0050] like Figure 8~Figure 10 As shown, in this embodiment, the insulating member 25 has a third outer surface 28 (i.e., a surface extending along the circumferential direction of the stator 20) located radially inward of the first outer surface 23 of the core member 22. On the third outer surface 28, a third recess 28a is formed in the axial direction of the stator 20 in a manner aligned with the first recess 23a.

[0051] The stator 20 of the present embodiment includes an insulating cap 31 disposed between the insulating member 25 and the frame 40. The insulating cap 31 is made of an insulating resin. The insulating cap 31 includes: an outer peripheral portion 32 extending over the entire circumference of the stator 20 and covering the insulating member 25 (or the coil 29) from the outer peripheral side; and an extension portion 34 extending radially inward from the outer peripheral portion 32 and covering the insulating member 25 (or the coil 29) from one axial side (i.e., the side where the coil 29 is exposed in the axial direction of the stator 20).

[0052] The outer peripheral portion 32 of the insulating cap 31 is mounted on the third outer surface 28 of the insulating member 25 in a manner that surrounds the third outer surface 28. The outer peripheral portion 32 has a fourth outer surface 33 (i.e., a surface extending along the circumferential direction of the stator 20) that is located radially outward of the first outer surface 23 of the core member 22. The fourth outer surface 33 of the present embodiment extends over the entire circumference, but is not limited to this. For example, the outer peripheral portion 32 may be shaped like a spur gear, and a plurality of fourth outer surfaces 33 may be intermittently arranged in the circumferential direction of the stator 20. The fourth outer surface 33 in the insulating cap 31 and its vicinity are an example of the first portion. The fourth outer surface 33 of the insulating cap 31 is an example of the outermost peripheral portion of the first portion.

[0053] The distance R1 from the fourth outer surface 33 of the insulating cap 31 to the axis O of the stator 20 (i.e., the radius R1 of a circle centered on the axis O and circumscribed to the fourth outer surface 33) is greater than the distance R2 from the outermost circumference of the core member 22 to the axis O of the stator 20 (i.e., the radius R2 of a circle centered on the axis O and circumscribed to the first outer surface 23 of the core member 22). Fig.10 As shown, when the stator 20 is inserted into the frame 40, the core member 22 is inserted in the front direction ( Fig.10 The corner portion of the fourth outer surface 33 and the vicinity thereof is hidden from the insertion direction ( Fig.10 in the upper part).

[0054] Implementation Method 4

[0055] Embodiment 4 of the present disclosure will be described. The motor 10 of this embodiment is different from the above-described embodiment 3 in that the stator 20 includes a ring 35. Hereinafter, mainly the differences from the above-described embodiment 3 will be described.

[0056] Fig.11 It is a perspective view showing the motor 10 according to the fourth embodiment. Fig.12 The main part of the fourth embodiment is enlarged and shown in the middle of inserting the stator 20 into the frame 40. Fig.11 It should be noted that the split core 21 of the fourth embodiment is the same as the split core 21 of the third embodiment. Fig. 9 It should be noted that the outline of the motor 10 of the fourth embodiment is the same as that of the motor 10 of the first embodiment, and its cross-sectional view is the same as that of the motor 10 of the first embodiment. Fig.13 It should be noted that in Fig.11 The rotor 50 and the frame 40 are omitted.

[0057] like Fig. 9 , Fig.11 as well as Fig.12 As shown, the stator 20 of the present embodiment includes a ring 35 arranged on the outer peripheral side of the insulating member 25. The ring 35 is made of an insulating resin. The ring 35 is installed on the third outer surface 28 of the insulating member 25 in a manner of surrounding it. The ring 35 has a fifth outer surface 36 (i.e., a surface extending along the circumferential direction of the stator 20) located radially outward of the first outer surface 23 of the core member 22. The fifth outer surface 36 of the present embodiment extends over the entire circumference, but is not limited to this. For example, the ring 35 may also be shaped like a spur gear, and a plurality of fifth outer surfaces 36 may be intermittently arranged in the circumferential direction of the stator 20. The fifth outer surface 36 in the ring 35 and its vicinity are an example of the first portion. The fifth outer surface 36 of the ring 35 is an example of the outermost peripheral portion of the first portion.

[0058] The distance R1 from the fifth outer surface 36 of the ring 35 to the axis O of the stator 20 (i.e., the radius R1 of a circle centered on the axis O and circumscribed to the fifth outer surface 36) is greater than the distance R2 from the outermost peripheral portion of the core member 22 to the axis O of the stator 20 (i.e., the radius R2 of a circle centered on the axis O and circumscribed to the first outer surface 23 of the core member 22). Fig.12 As shown, when the stator 20 is inserted into the frame 40, the core member 22 is inserted in the front direction ( Fig.12 The corner portion of the frame 40 is prevented from contacting the frame 40. This is because, as shown in the figure, the corner portion is hidden behind the fifth outer surface 36 and its vicinity in the insertion direction ( Fig.12 in the upper part).

[0059] The preferred embodiments of the present disclosure are described, but the scope of the present disclosure should not be limited by the description. For example, as long as no technical contradiction occurs, the matters described in two or more technical solutions arbitrarily selected from the multiple technical solutions described in the attached technical solutions can be combined.

[0060] Industrial Applicability

[0061] The present disclosure can be applied to motors.

[0062] Description of Reference Numerals

[0063] 10: Motor

[0064] 20: Stator

[0065] 21: Split core

[0066] 22: Core member

[0067] 23: First outer surface (outermost peripheral portion of the core member)

[0068] 23a: First recess

[0069] 24: Tooth

[0070] 25: Insulation

[0071] 26: Convex part (first part)

[0072] 26a: Protruding end (the outermost peripheral part of the first part)

[0073] 27: Second outer surface (outermost portion of the first portion)

[0074] 27a: Second recess

[0075] 28: Third outer surface

[0076] 28a: Third recess

[0077] 29: Coil

[0078] 31: Insulation cap

[0079] 32: Peripheral part

[0080] 33: Fourth outer surface (outermost portion of the first portion)

[0081] 34: Extension

[0082] 35: Ring

[0083] 36: Fifth outer surface (outermost portion of the first portion)

[0084] 40: Framework

[0085] O: Axis.

Claims

1. A motor comprising: a stator including a plurality of split cores each including a core member and an insulator and connected in an annular shape; and an annular frame into which the stator is inserted by shrink fitting or press fitting, The stator includes at least one first portion having a lower hardness than the frame. A distance R1 from the outermost circumference of the first portion to the axial center of the stator is greater than or equal to a distance R2 from the outermost circumference of the core member to the axial center of the stator. The first portion is disposed at least in front of the core member in the insertion direction of the stator with respect to the frame.

2. The motor according to claim 1, wherein: The first portion is formed integrally with the insulating member.

3. The motor according to claim 1, wherein: The stator further includes an insulating cap disposed between the insulating member and the frame. The first portion is integrally formed with the insulating cap.

4. The motor according to claim 1, wherein: The stator further includes a ring disposed on the outer circumference of the insulating member. The first portion is integrally formed with the ring.

5. The motor according to any one of claims 1 to 4, wherein: A plurality of the first portions are intermittently provided in the circumferential direction of the stator.

6. The motor according to any one of claims 1 to 4, wherein: The difference between the distance R1 and the distance R2 is greater than or equal to 0 mm and less than or equal to 0.1 mm.

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