Rotary electric machine and industrial machine

Abstract

A rotary electric machine includes a rotor (3), a stator core (21) having a plurality of slots (21c) between the rotor (3) and a back yoke (21a), a resin bobbin (22) having a plurality of coil insertion holes (22a) arranged in a radial direction of the stator core (21) and embedded in the slots (21c), and a first void hole (22ca) formed in the stator core (21). A first void hole (22ca) is provided on a side wall (22c) closest to the back yoke (21a) among the side walls of the bobbin (22).

Description

Technical Field

[0001] The present invention relates to rotating electrical machines and industrial machinery. Background Art

[0002] A rotating electric machine has been developed that uses a segment coil whose conductor is a flat wire with a flat cross-section to increase the winding space factor of the stator, thereby achieving high output density and miniaturization. The rotating electric machine of Patent Document 1 fits the segmented segment coils into a plurality of coil insertion holes formed on a bobbin located in a stator slot, thereby achieving further miniaturization, high production efficiency, and cost reduction.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-126031 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The rotating electric machine disclosed in Patent Document 1 has a tendency that when the distance between the segment coil in the coil frame and the back yoke of the stator is relatively close, the inductance increases and the controllability of the rotating electric machine decreases, while when the distance is relatively far, the inductance decreases and the controllability improves. For example, if the side wall of the coil frame between the back core of the stator iron core and the segment coil is locally thickened, the distance can be ensured, thereby suppressing the decrease in controllability.

[0008] However, when the side wall of the coil frame is locally thickened, the resin will be retained in the thicker side wall portion when the coil frame is resin-molded, and it will be difficult for the resin to reach other thinner side wall portions, such as the partition wall portion that separates two adjacent segmented coils in the coil frame. This increases the possibility of poor molding such as cracks and weld lines in the coil frame.

[0009] Technical means of solving problems

[0010] In order to solve the above-mentioned problems, the present invention includes: a rotor; a stator core having a plurality of slots between the rotor and the back yoke; a resin coil frame, which is embedded in the slots and has a plurality of coil insertion holes arranged along the radial direction of the stator core; and a first gap hole, which is arranged on the side wall of the coil frame that is closest to the back yoke, i.e., the back yoke side wall.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to suppress a decrease in controllability of a rotating electrical machine and suppress defective forming of a coil bobbin. Other problems, features, and effects than those described above will become apparent from the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional perspective view showing a schematic structure of a rotating electrical machine according to the first embodiment of the present invention.

[0014] Figure 2 It is a cross-sectional view of a rotating electrical machine according to the first embodiment of the present invention.

[0015] Figure 3 It is a partially enlarged view of a cross section of the rotating electrical machine according to the first embodiment of the present invention.

[0016] Figure 4 Schematic diagram showing a magnetic circuit generated around an armature winding inserted into a plurality of coil insertion holes provided in a coil bobbin according to a comparative example.

[0017] Figure 5 This is a magnetic circuit diagram that expresses a magnetic circuit generated around an armature winding of a rotating electrical machine using lumped parameters according to a comparative example.

[0018] Figure 6 This is a magnetic circuit diagram expressing a magnetic circuit generated around another armature winding of a rotating electrical machine according to a comparative example using lumped parameters.

[0019] Figure 7 The diagram is a schematic diagram showing a magnetic circuit generated around an armature winding inserted into a plurality of coil insertion holes provided in a coil bobbin according to the first embodiment of the present invention.

[0020] Figure 8 This is a magnetic circuit diagram expressing a magnetic circuit generated around an armature winding of a rotating electrical machine using lumped parameters according to the first embodiment of the present invention.

[0021] Fig. 9 This is a magnetic circuit diagram expressing a magnetic circuit generated around another armature winding of the rotating electrical machine according to the first embodiment of the present invention using lumped parameters.

[0022] Fig.10 It is a partially enlarged view of a cross section of a rotating electrical machine according to a second embodiment of the present invention.

[0023] Fig.11 It is a partially enlarged view of a cross section of a rotating electrical machine according to a third embodiment of the present invention.

[0024] Fig.12 It is a partially enlarged view of a cross section of a rotating electrical machine according to a fourth embodiment of the present invention. DETAILED DESCRIPTION

[0025] Hereinafter, the configuration and operation of the rotating electric machines according to the first to fourth embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals denote the same parts.

[0026] (First Embodiment)

[0027] Figure 1 is a cross-sectional perspective view schematically showing the structure of a rotating electrical machine 1 according to a first embodiment of the present invention. Figure 2 is a cross-sectional view of a rotating electrical machine 1 according to a first embodiment of the present invention. Figure 3 It is a partially enlarged view of a cross section of the rotating electrical machine 1 according to the first embodiment of the present invention.

[0028] The rotating electrical machine 1 is, for example, a distributed winding inner rotor type permanent magnet synchronous motor, and can be used as an electric motor that is a power source for industrial machinery such as a compressor.

[0029] like Figure 1 As shown, a stator 2 , a rotor 3 , a shaft 4 , a housing 5 and an end bracket 6 are provided in a rotating electrical machine 1 .

[0030] The stator 2 is a component that generates magnetic force using the power supplied from the power source to rotate the rotor 3 that is opposed to the rotor 3 via a gap, and includes a stator core 21 and a plurality of coil frames 22 (see FIG. Figure 2 , 3 ) and multiple armature windings 23.

[0031] The rotor 3 is a part that rotates under the action of the magnetic force generated by the stator 2. In the rotor 3, a rotor core 31 composed of a plurality of laminated plates, a plurality of magnet insertion holes 32 formed in the rotor core 31, and a plurality of permanent magnets 33 accommodated in the plurality of magnet insertion holes 32 are provided.

[0032] A through hole 31a is provided at the center of the rotor core 31, and the shaft 4 is fixed in the through hole 31a by press-fitting or the like. In addition, the permanent magnet 33 can be, for example, a ferrite magnet, a neodymium magnet, or a samarium cobalt magnet, and the shape of the permanent magnet 33 can be, for example, a square or a segmented (C) shape. In addition, it is preferred to insert one magnet into the magnet insertion hole 32.

[0033] The shaft 4 is an input / output shaft that rotates together with the rotor 3, and is rotatably supported by a bearing 4a that is embedded in the end bracket 6. The housing 5 is a cylindrical member that covers and protects the stator 2, and the stator core 21 is embedded therein.

[0034] The end bracket 6 is mounted on both sides of the housing 5 in the axial direction and is a disc-shaped member that closes both ends of the housing 5 in the axial direction. The end bracket 6 includes a first end bracket 6a having a flange and from which the shaft 4 extends out of the center, and a second end bracket 6b having no flange and from which the shaft 4 does not extend out. By closing both ends of the housing 5 with the first end bracket 6a and the second end bracket 6b, the stator 2 and the rotor 3 are sealed and protected.

[0035] The rotating electrical machine 1 configured in this manner becomes a motor using the shaft 4 as an output shaft by supplying electric power to the stator 2 , and becomes a generator by supplying rotational power using the shaft 4 as an input shaft.

[0036] Next, the stator core 21 of this embodiment will be described in detail. Figure 2 As shown, the stator core 21a is provided with a circular back yoke 21a and a plurality of (48 in this embodiment) teeth 21b extending from the inner peripheral side of the back yoke 21a toward the central axis of the back yoke 21a. In the stator core 21, the plurality of teeth 21b are located between the back yoke 21a and the rotor 3, and are opposite to the rotor 3. The stator core 21 is formed into a cylindrical shape by laminating steel plates having the back yoke 21a and the plurality of teeth 21b.

[0037] Between two adjacent teeth 21b among the plurality of teeth 21b, there is formed a core slot (slot) 21c for inserting the armature winding 23. Thus, the stator 2 has a plurality of slots 21c between the rotor 3 and the back yoke 21a.

[0038] In addition, if Figure 3 As shown, the cross-sectional shape of the tooth 21b can be formed into a shape that becomes thinner toward the center direction of the stator core 21 in such a way that the cross-sectional shape of the slot 21c is rectangular. In addition, in the stator core 21, the joint 21ab between the side surfaces of the two teeth 21b surrounding the slot 21c and the inner side surface of the back yoke 21a is preferably a curved surface.

[0039] The coil frame 22 is an insulator, made by resin molding, embedded in the slot 21c, and has a plurality of (four in this embodiment) coil insertion holes 22a arranged along the radial direction of the stator core 21. The plurality of armature windings 23 are insulated from the stator core 21 (back yoke 21a and teeth 21b) by the coil frame 22.

[0040] like Figure 3 As shown, a plurality of coil insertion holes 22a and a plurality of side walls (a back yoke side side wall 22c, a slot opening side side wall 22d, a plurality of partition walls 22b and two tooth side side walls 22e) are provided in the coil bobbin 22.

[0041] A plurality of (three in this embodiment) partition walls 22b are located between two adjacent coil insertion holes 22a among the plurality of coil insertion holes 22a, and are insulating walls for preventing short circuits between the armature windings 23 inserted in the plurality of coil insertion holes 22a.

[0042] like Figure 3 As shown, the back yoke side wall 22c is the side wall closest to the back yoke 21a among the multiple side walls of the coil bobbin 22, and is an insulating wall for preventing the back yoke 21a from short-circuiting with the armature winding 23. The back yoke side wall 22c is provided with a first gap hole 22ca.

[0043] The first air hole 22ca is preferably a through hole that penetrates in the axial direction of the stator core 21. The thickness t22c of the back yoke side wall 22c is preferably thicker than the thickness t22b of the partition wall 22b. Furthermore, the first air hole 22ca is preferably filled with resin.

[0044] The width w22ca of the first air hole 22ca in the radial direction of the stator core 21 is preferably greater than the thickness t22b of the partition wall 22b. In addition, the resin thickness t1 between the first air hole 22ca and the coil insertion hole 22aa closest to the first air hole 22ca among the plurality of coil insertion holes 22a is preferably substantially the same as the thickness t22b of the partition wall.

[0045] Furthermore, the resin thickness t1 to t4 around the first air hole 22ca is preferably substantially the same as the thickness t22b of the partition wall. In addition, the width w22ca of the first air hole 22ca in the radial direction of the stator core 21 is preferably smaller than the width t22a of each of the plurality of coil insertion holes 22a in the radial direction of the stator core 21.

[0046] In addition, it is preferable that a corner portion 22cb of the back yoke side wall 22c that faces the joining portion 21ab formed in the groove 21c is chamfered along the curved surface of the joining portion 21ab.

[0047] The slot opening side wall 22d is the side wall closest to the opening of the slot 21c among the side walls of the coil frame 22. The two tooth side walls 22e are insulating walls located between the plurality of coil insertion holes 22a and the teeth 21b to prevent short circuits between the armature windings 23 respectively inserted into the plurality of coil insertion holes 22a and the teeth 21b.

[0048] As the material of the coil frame 22, for example, liquid crystal resin, PPS resin, POE resin, aramid resin, polyimide resin, polyester resin, PE resin, PP resin, epoxy resin and other resins can be used, and two kinds of resins can be used in combination. In addition, fillers such as inorganic fillers, organic fillers, inorganic fibers, and organic fibers can also be mixed and used.

[0049] The armature winding 23 is, for example, a flat wire having a flat cross-sectional shape, is inserted into each of the plurality of coil insertion holes 22 a , and is wound around the plurality of teeth 21 b in, for example, a distributed winding method.

[0050] (Function / Effect)

[0051] Figure 4 1 is a schematic diagram showing a magnetic circuit generated around the armature winding 23 inserted into the plurality of coil insertion holes 22 a provided in the coil bobbin 122 according to the comparative example.

[0052] When current flows through the armature winding 23a, a current is generated around the armature winding 23a. Figure 4 When current flows through the armature winding 23b, the magnetic flux Φ23a of the magnetic circuit shown in FIG. 2 generates a magnetic flux around the armature winding 23b. Figure 4 The magnetic flux of the magnetic circuit shown is Φ23b.

[0053] Figure 5 : is a magnetic circuit diagram that expresses the magnetic circuit generated around the armature winding 23a of the rotating electrical machine using lumped parameters according to the comparative example. Figure 5 As shown, the magnetic circuit around the armature winding 23a has a magnetic resistance R21a on the back yoke 21a side, a magnetic resistance R21b on the tooth 21b side, and a magnetic resistance R22b on the partition wall 22b side. Assuming the magnetomotive force of the armature winding 23a is I, the magnetic flux Φ23a is:

[0054] Φ23a=I / (R21a+R21b×2+R22b).

[0055] Figure 6 : is a magnetic circuit diagram that expresses the magnetic circuit generated around the armature winding 23b of the rotating electrical machine using lumped parameters according to the comparative example. Figure 6 As shown, the magnetic circuit around the armature winding 23b has a magnetic resistance R21b on the tooth 21b side and a magnetic resistance R22b on the partition wall 22b side. Assuming the magnetomotive force of the armature winding 23b is I, the magnetic flux Φ23b is:

[0056] Φ23b=I / ((R21b+R22b)×2).

[0057] Here, the magnetic resistance R21a and the magnetic resistance R21b are roughly equal because the magnetic circuit is formed by the back yoke 21a and the teeth 21b, which are magnetic bodies. On the other hand, the magnetic resistance R22b is roughly equivalent to air because the magnetic circuit is formed by the partition wall 22b, which is a non-magnetic body. Therefore, the magnetic resistance R22b is 100 to 10,000 times greater than the magnetic resistance R21a and the magnetic resistance R21b, and the magnetic flux Φ23a is larger than the magnetic flux Φ23b. However, the magnetic flux of the magnetic flux Φ23a that passes through the back yoke 21a does not interlink with the rotor 3, and is therefore an ineffective magnetic flux that does not contribute to the rotational torque of the rotor 3.

[0058] On the other hand, when the rotating electrical machine 1 of the present embodiment is used as a permanent magnet synchronous motor for synchronous drive, the positional relationship between the plurality of permanent magnets 33 of the rotor 3 and the plurality of teeth 21b of the stator 2 changes continuously, so that the magnetic circuit in the motor changes. When the magnetic circuit changes, if magnetic saturation occurs in the teeth, the inductance changes nonlinearly, and the current flowing in the armature winding pulsates. When the pulsation of the current exceeds the control range of the control device, the pulsation becomes significant, and the controllability of the motor is reduced. That is, when the inductance of the armature winding is large, the variation of the current pulsation caused by magnetic saturation increases, and the controllability of the motor is reduced.

[0059] On the other hand, if the inductance can be reduced, the phase difference between the terminal voltage and the no-load induced electromotive force, that is, the load angle, can be reduced. Therefore, for example, when performing sensorless control, the effective load range can be expanded, thereby improving the controllability of the motor.

[0060] Figure 7 2 is a schematic diagram showing a magnetic circuit generated around the armature winding 23 inserted into the plurality of coil insertion holes 22a provided in the coil frame 22 according to the present embodiment. When current flows through the armature winding 23a, a magnetic circuit is generated around the armature winding 23a. Figure 7 When current flows through the armature winding 23b, the magnetic flux Φ23a of the magnetic circuit shown in FIG. 2 generates a magnetic flux around the armature winding 23b. Figure 7 The magnetic flux of the magnetic circuit shown is Φ23b.

[0061] Figure 8 : is a magnetic circuit diagram that expresses the magnetic circuit generated around the armature winding 23a of the rotary electric machine 1 using lumped parameters according to the present embodiment. Figure 8 As shown, the magnetic circuit around the armature winding 23a has a magnetic resistance R21b on the tooth 21b side and a magnetic resistance R22b on the partition wall 22b side.

[0062] Assuming the magnetomotive force of the armature winding 23a is I, the magnetic flux Φ23a is:

[0063] Φ23a=I / ((R21b+R22b)×2).

[0064] Fig. 9 : is a magnetic circuit diagram that expresses the magnetic circuit generated around the armature winding 23b of the rotary electric machine 1 using lumped parameters according to the present embodiment. Fig. 9 As shown, the magnetic circuit around the armature winding 23b has a magnetic resistance R21b on the tooth 21b side and a magnetic resistance R22b on the partition wall 22b side.

[0065] Assuming the magnetomotive force of the armature winding 23b is I, the magnetic flux Φ23b is:

[0066] Φ23b=I / ((R21b+R22b)×2).

[0067] Here, the magnetic circuit generated around the armature winding 23 a of the rotating electric machine 1 according to the present embodiment does not include the magnetic resistance R21 a on the back yoke 21 a side, so the magnetic flux Φ23 a and the magnetic flux Φ23 b are substantially equal.

[0068] On the other hand, the magnitude of the ratio of the magnetic flux Φ to the magnetomotive force I indicates the inductance of the armature winding 23 , so the rotary electric machine 1 of the present embodiment can reduce the inductance compared to the rotary electric machine of the comparative example.

[0069] The coil frame 22 can utilize the first gap hole 22ca to make the coil insertion hole 22aa closest to the back yoke 21a among the multiple coil insertion holes 22a arranged along the radial direction of the stator core 21 away from the back yoke 21a. Thus, the magnetic circuit around the armature winding 23a inserted in the coil insertion hole 22aa can be made to not include the magnetic resistance R21a on the back yoke 21a side, similar to the magnetic circuit around the armature winding 23 inserted in other coil insertion holes 22a. Therefore, the magnetic flux Φ1 can be reduced, the inductance is reduced, and the controllability of the motor can be improved. Thus, by making the armature winding 23 away from the back yoke 21a, the controllability of the motor can be improved.

[0070] That is, the rotating electric machine 1 of this embodiment includes a rotor 3, a stator core 21, a resin coil frame 22 and a first gap hole 22ca, wherein the stator core 21 has a plurality of slots 21c between the rotor 3 and the back yoke 21a, the coil frame 22 has a plurality of coil insertion holes 22a arranged along the radial direction of the stator core 21 and embedded in the slots 21c, and the first gap hole 22ca is arranged on the side wall of the coil frame 22 which is closest to the back yoke 21a, namely, the back yoke side side wall 22c.

[0071] Providing the first air hole 22ca on the back yoke side wall 22c, which is the side wall of the bobbin 22 closest to the back yoke 21a, ensures a distance between the armature winding 23a and the back yoke 21a. This prevents an increase in inductance, thereby improving controllability of the rotating electrical machine 1.

[0072] Furthermore, by providing the first gap hole 22ca, it is possible to prevent the resin thickness t1 to t4 of the back yoke side wall 22c from being extremely increased compared to the resin thickness of the side wall of other parts. As a result, it is possible to prevent local retention of resin during the resin molding of the coil frame 22, and thus it is possible to prevent the coil frame 22 from being poorly molded. That is, according to the rotary electric machine 1 of this embodiment, it is possible to suppress the reduction in the controllability of the rotary electric machine 1 and suppress the poor molding of the coil frame 22.

[0073] In addition, in the coil frame 22 of the present embodiment, preferably, the first void hole 22ca provided on the back yoke side wall 22c is a through hole that penetrates the back yoke side wall 22c in the axial direction of the stator core 21. Thus, the first void hole 22ca is easily formed, and the bias (unevenness) of the resin pressure during the resin forming of the coil frame 22 can be suppressed, and the formation defects such as cracks can be prevented.

[0074] In addition, in the coil frame 22 of the present embodiment, it is preferred that the back yoke side side wall 22c is thicker than the partition wall 22b located between two adjacent coil insertion holes 22a among the plurality of coil insertion holes 22a. Thus, compared with a case where the thickness t22c of the back yoke side side wall 22c is less than or equal to the thickness t22b of the partition wall 22b, the inductance can be reduced, thereby improving the controllability of the motor.

[0075] In addition, it is preferable that the width w22ca of the first air hole 22ca in the radial direction of the stator core 21 of the present embodiment is larger than the thickness t22b of the partition wall 22b. Thus, the thickness t22c of the back yoke side wall 22c in the radial direction of the stator core 21 is larger than the thickness t22b of the partition wall 22b, and the resin thickness t1 to t4 around the first air hole 22ca can be made thinner. Therefore, the inductance can be reduced, and the reduction in the controllability of the rotating electric machine 1 can be suppressed, and the resin thickness t1 to t4 around the first air hole 22ca can be made thinner, and the poor forming of the coil frame 22 can be suppressed.

[0076] In addition, it is preferred that the resin thickness t1 between the first void hole 22ca of the present embodiment and the coil insertion hole 22aa closest to the first void hole 22ca among the plurality of coil insertion holes 22a is substantially the same as the thickness t22b of the partition wall 22b. Thus, the bias (unevenness) of the resin pressure during the coil frame resin molding can be suppressed, and the occurrence of cracks and other molding defects can be further prevented.

[0077] Furthermore, the resin thickness t1 to t4 around the first air hole 22ca of the present embodiment is preferably substantially the same as the thickness t22b of the partition wall 22b. This can further suppress the bias (unevenness) of the resin pressure during the coil bobbin resin molding, thereby further preventing molding defects such as cracks.

[0078] In addition, it is preferred that the width w22ca of the first gap hole 22ca in the radial direction of the stator core 21 of the present embodiment is smaller than the width t22a of each of the plurality of coil insertion holes 22a in the radial direction of the stator core 21. Thus, the width t22c of the back yoke side wall 22c in the radial direction of the stator core 21 can be reduced, thereby suppressing the reduction in the space factor of the armature winding 23 wound on the teeth 21b.

[0079] In addition, the joint 21ab between the side surfaces of the two teeth 21b surrounding the slot 21c and the inner surface of the back yoke 21a is preferably a curved surface. This makes it easier for magnetic flux to flow in the joint 21ab, which reduces magnetic resistance to interlinked magnetic flux and reduces magnetic loss.

[0080] In addition, it is preferable that resin is injected into the first air holes 22 ca of the present embodiment, whereby the strength of the coil bobbin 22 can be improved.

[0081] (Second Embodiment)

[0082] Fig.10 This is a partially enlarged view of a cross section of a rotating electrical machine according to a second embodiment of the present invention. This embodiment differs from the first embodiment in that a gap extending in the axial direction of the stator core 21, namely a back yoke side opening 22ce, is provided on the resin wall 22cc between the first gap hole 22ca and the back yoke 21a.

[0083] Thus, in the mold for resin molding of the coil bobbin 222, the through-hole molding protrusion provided on the mold for forming the first gap hole 22ca is coupled to the outer wall of the mold via the mold portion for forming the back yoke side opening 22ce. Therefore, during the injection molding process of the coil bobbin 222, the deflection and vibration of the through-hole molding protrusion caused by the pressure of the resin injected into the mold are suppressed, and molding defects can be suppressed.

[0084] In addition, in order to prevent the strength of the resin wall 22cc from being reduced, the back yoke side opening portion 22ce is preferably provided only on a portion of the axial direction of the stator core 21. In this case, in order to effectively suppress the deflection and vibration occurring in the through-hole forming protrusion of the mold, the mold portion for forming the back yoke side opening portion 22ce is preferably provided on the front end side of the through-hole forming protrusion. Therefore, the back yoke side opening portion 22ce is preferably formed on the front end side of the through-hole forming protrusion of the mold.

[0085] (Third Embodiment)

[0086] Fig.11 This is a partially enlarged view of a cross section of a rotating electrical machine according to a third embodiment of the present invention. This embodiment differs from the second embodiment in that a second gap hole 22da is provided on the side wall of the coil frame 322 closest to the opening of the slot 21c (the slot opening side side wall 22d).

[0087] Thus, the resin thickness t5 to t8 around the second voids 22da of the slot opening side wall 22d is reduced, thereby preventing the resin from being locally accumulated on the slot opening side wall 22d during the resin molding of the coil bobbin 322. Thus, molding defects of the coil bobbin 22 can be further prevented.

[0088] Preferably, the thickness t5 to t8 of the resin around the second void 22da is substantially the same as the thickness t22b of the partition wall 22b. This can further suppress the unevenness of the resin pressure during the resin molding of the coil bobbin 322 and further suppress molding defects such as cracks.

[0089] Furthermore, it is preferable that resin is injected into the second air holes 22da. This can improve the strength of the coil bobbin 322.

[0090] (Fourth Embodiment)

[0091] Fig.12 1 is a partially enlarged view of a cross section of a rotating electrical machine according to a fourth embodiment of the present invention. This embodiment differs from the third embodiment in that a slot opening side opening 22de, which is a gap extending in the axial direction of the stator core 21, is provided on the resin wall 22dc between the second void hole 22da and the opening of the slot 21c.

[0092] Thus, in the mold for resin molding of the coil bobbin 422, the through-hole molding protrusion provided on the mold for forming the second void hole 22da is coupled to the outer wall of the mold via the protrusion for forming the slot opening side opening 22de. Therefore, during the injection molding process of the coil bobbin 422, the deflection and vibration of the through-hole molding protrusion caused by the pressure of the resin injected into the mold are suppressed, so that molding defects can be suppressed.

[0093] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and are not limited to having all the structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0094] In addition, the present invention may be implemented as follows: In the rotating electrical machine 1, the number of poles and the number of slots are shown as 8 poles and 48 slots, but the present invention is not limited to this, and the combination of the number of poles and the number of slots is arbitrary, for example, a combination of 4 poles and 48 slots or 2 poles and 24 slots may be used.

[0095] In addition, the above shows the case where a square or segmented (C) ferrite magnet, neodymium magnet, or samarium cobalt magnet is used as the permanent magnet 33. However, it is not limited to this method, and other magnets and other shapes can also be used. In addition, it is not limited to the case where one magnet is inserted into the magnet insertion hole 32, and multiple permanent magnets 33 can also be inserted in the axial direction, circumferential direction, or radial direction of the stator 2.

[0096] In the above-described embodiment, the cross-sectional shape of the tooth 21b is formed so that the cross-sectional shape of the slot 21c is rectangular and becomes narrower toward the center of the stator core 21. However, the present invention is not limited thereto, and for example, the cross-sectional shape of the tooth 21b may be rectangular and the cross-sectional shape of the slot 21c may be narrower toward the center of the stator core 21. In addition, the front end of the tooth 21b may be expanded in the circumferential direction of the stator core 21, and the cross-sectional shape of the tooth 21b may be T-shaped.

[0097] In addition, in the above embodiment, the stator core 21 is shown as a stator core 21 formed by laminating steel plates integrally provided with a back yoke 21a and a plurality of teeth 21b. However, this is not limited to this, and the plurality of teeth 21b and the back yoke 21a may be manufactured from different steel plates, and the plurality of laminated teeth 21b may be fixedly mounted on the laminated back yoke 21a.

[0098] In addition, the armature winding 23 preferably uses a flat wire in order to increase the winding space factor, but is not limited thereto, and may be, for example, a round wire or a stranded wire. When a round wire or a stranded wire is used as the armature winding 23, it is preferred that the shape of the coil insertion hole 22a be deformed according to the cross-sectional shape of the armature winding 23. In addition, as the armature winding 23, for example, a conductor mainly composed of copper and coated with an insulating film (e.g., varnish, engineering plastic) is preferred.

[0099] Description of Reference Numerals

[0100] 1...rotating electric machine, 2...stator, 3...rotor, 21...stator core, 21a...back yoke, 21aa...inner side surface of back yoke, 21ab...joining portion, 21b...teeth, 21ba...tooth side surface, 21c...slots, 22, 122, 222, 322, 422...coil frame, 22a...coil insertion hole, 22b...partition wall, 22c...back yoke side wall, 22ca...first gap hole, 22cc...resin wall, 22ce...back yoke side opening, 22d...slot opening side wall, 22da...second gap hole, 22dc...resin wall, 22de...slot opening side opening, 23...armature winding, 31...rotor core, 31a...through hole, 32...magnet insertion hole, 33...permanent magnet.

Claims

1. A rotating electrical machine, characterized in that: include: Rotor; a stator core having a plurality of slots between the rotor and the back yoke; a coil frame made of resin, which is embedded in the slot and has a plurality of coil insertion holes arranged along the radial direction of the stator core; and The first gap hole is provided on a side wall of the coil frame which is closest to the back yoke, that is, a back yoke side wall.

2. The rotating electrical machine according to claim 1, characterized in that: The first air hole is a through hole that penetrates the back yoke-side side wall in the axial direction of the stator core.

3. The rotating electrical machine according to claim 1, characterized in that: The back yoke-side side wall is thicker than a partition wall located between two adjacent coil insertion holes among the plurality of coil insertion holes.

4. The rotating electrical machine according to claim 3, characterized in that: A width of the first air gap hole in a radial direction of the stator core is larger than a thickness of the partition wall.

5. The rotating electrical machine according to claim 3, characterized in that: The thickness of the resin between the first air hole and the coil insertion hole closest to the first air hole among the plurality of coil insertion holes is substantially the same as the thickness of the partition wall.

6. The rotating electrical machine according to claim 3, characterized in that: The thickness of the resin around the first void hole is substantially the same as the thickness of the partition wall.

7. The rotating electrical machine according to claim 1, characterized in that: A width of the first air gap hole in the radial direction of the stator core is smaller than a width of each of the plurality of coil insertion holes in the radial direction of the stator core.

8. The rotating electrical machine according to claim 1, characterized in that: The slot is formed between two teeth adjacent to each other in the circumferential direction among a plurality of teeth protruding from the back yoke toward the center of the stator core. A joining portion between a side surface of each of the two teeth surrounding the groove and an inner side surface of the back yoke is a curved surface.

9. The rotating electrical machine according to claim 1, characterized in that: Resin is injected into the first void holes.

10. The rotating electrical machine according to claim 1, characterized in that: A slit extending in the axial direction of the stator core is formed on the resin wall between the first air hole and the back yoke.

11. The rotating electrical machine according to claim 1, characterized in that: A second gap hole is provided on a side wall of the coil frame that is closest to the opening of the slot.

12. The rotating electrical machine according to claim 11, characterized in that: The thickness of the resin around the second air hole is substantially the same as the thickness of a partition wall between two adjacent coil insertion holes among the plurality of coil insertion holes.

13. The rotating electrical machine according to claim 11, characterized in that: The second void holes are filled with resin.

14. The rotating electrical machine according to claim 11, characterized in that: A slit-shaped second opening extending in the axial direction of the stator core is formed on the resin wall between the second air hole and the opening of the slot.

15. An industrial machine, characterized in that: It comprises a rotating electric machine as claimed in claim 1.

Images