Rotating electrical machines and industrial machinery

Abstract

To provide a rotating electric machine capable of controlling bobbin molding defects while reducing the decrease of controllability thereof.SOLUTION: The rotating electric machine includes: a rotor 3; a stator core 21 having multiple slots 21c between the rotor 3 and a back yoke 21a; a resin bobbin 22 that has multiple coil insertion holes 22a arranged along a diameter direction of the stator core 21, which is fitted into the slot 21c; and a first void hole 22ca formed in a side wall 22c closest to the back yoke 21a in the side wall of the bobbin 22.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine and an industrial machine.

Background Art

[0002] A rotating electrical machine has been developed in which a segment coil having a flat cross-section in the form of a flat wire is used for a conductor wire to increase the winding space factor of a stator, achieve a higher output density, and reduce the size. The rotating electrical machine of Patent Document 1 fits a divided segment coil into a plurality of coil insertion holes formed in a bobbin provided in a slot of a stator, thereby achieving further size reduction, high productivity, and cost reduction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a rotating electrical machine such as that of Patent Document 1, when the distance between the segment coil in the bobbin and the back yoke of the stator is relatively close, the inductance increases and the controllability of the rotating electrical machine decreases, and when the distance is relatively far, the inductance decreases and the controllability tends to improve. For example, if the side wall of the bobbin between the back core and the segment coil is locally thickened, the distance can be ensured and a decrease in controllability can be suppressed.

[0005] However, when the side wall of the bobbin is locally thickened, resin stays in the thick side wall portion when the bobbin is resin molded, and it becomes difficult for the resin to spread to other thin side wall portions, for example, the partition wall portion of the bobbin separating two adjacent segment coils, and the possibility of molding defects such as cracks and weld lines occurring in the bobbin increases.

Means for Solving the Problems

[0006] To solve the above problems, the present invention comprises a rotor, a stator core having a plurality of slots between the rotor and the back yoke, a resin bobbin fitted into the slots and having a plurality of coil insertion holes arranged along the radial direction of the stator core, and a first void hole provided in the side wall of the bobbin closest to the back yoke. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress a decrease in the controllability of a rotating electric machine and to suppress molding defects in the bobbin. Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional perspective view showing the schematic structure of a rotating electric machine according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view of a rotating electric machine according to the first embodiment of the present invention. [Figure 3] This is a partially enlarged cross-sectional view of a rotating electric machine according to the first embodiment of the present invention. [Figure 4] This is a schematic diagram showing the magnetic circuit generated around an armature winding inserted into multiple coil insertion holes provided in a bobbin of a comparative example. [Figure 5] This is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding of a rotating electric machine in a comparative example, expressed using lumped parameters. [Figure 6] This is a magnetic circuit diagram representing the magnetic circuit generated around another armature winding of a rotating electric machine in a comparative example, expressed using lumped parameters. [Figure 7] This is a schematic diagram showing a magnetic circuit generated around an armature winding inserted into a plurality of coil insertion holes provided in a bobbin according to the first embodiment of the present invention. [Figure 8] This is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding of a rotating electric machine according to the first embodiment of the present invention, using lumped parameters. [Figure 9]This is a magnetic circuit diagram representing the magnetic circuit generated around another armature winding of a rotating electric machine according to the first embodiment of the present invention, using lumped parameters. [Figure 10] This is a partially enlarged cross-sectional view of a rotating electric machine according to a second embodiment of the present invention. [Figure 11] This is a partially enlarged cross-sectional view of a rotating electric machine according to the third embodiment of the present invention. [Figure 12] This is a partially enlarged cross-sectional view of a rotating electric machine according to the fourth embodiment of the present invention. [Modes for carrying out the invention]

[0009] The configuration and operation of the rotating electric machine according to the first to fourth embodiments of the present invention will be described below with reference to the drawings. In each figure, the same reference numerals indicate the same part.

[0010] (First Embodiment) Figure 1 is a schematic cross-sectional perspective view showing the structure of the rotating electric machine 1 according to the first embodiment of the present invention, Figure 2 is a cross-sectional view of the rotating electric machine 1 according to the first embodiment of the present invention, and Figure 3 is a partially enlarged view of the cross-section of the rotating electric machine 1 according to the first embodiment of the present invention.

[0011] The rotating electric 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.

[0012] As shown in Figure 1, the rotating electric machine 1 is provided with a stator 2, a rotor 3, a shaft 4, a housing 5, and an end bracket 6.

[0013] The stator 2 is a component that generates a magnetic force using electricity supplied from a power source and rotates the rotor 3 opposite it through a gap. It has a stator core 21, a plurality of bobbins 22 (see Figures 2 and 3), and a plurality of armature windings 23.

[0014] The rotor 3 is a part that rotates due to the magnetic force generated by the stator 2. The rotor 3 is provided with 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 housed in the plurality of magnet insertion holes 32.

[0015] A through hole 31a is provided at the center of the rotor core 31, and a shaft 4 is fixed to the through hole 31a by press-fitting or the like. Further, for example, a ferrite magnet, a neodymium magnet, or a samarium cobalt magnet can be used as the permanent magnet 33, and for example, a rectangular shape or a segment (C) shape can be used as the shape of the permanent magnet 33. Further, it is preferable that one magnet is inserted into the magnet insertion hole 32.

[0016] The shaft 4 is an input / output shaft that rotates together with the rotor 3, and is rotatably supported by a bearing 4a fitted into an end bracket 6. The housing 5 is a cylindrical member into which the stator core 21 is fitted and that covers and protects the stator 2.

[0017] The end brackets 6 are attached to both sides in the axial direction of the housing 5 and are disk-shaped members that close both ends in the axial direction of the housing 5. The end brackets 6 include a first end bracket 6a in which the shaft 4 protrudes from the center and a flange is provided, and a second end bracket 6b in which the shaft 4 does not protrude and there is no flange. 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.

[0018] The rotating electrical machine 1 configured as described above becomes a motor having the shaft 4 as an output shaft by supplying power to the stator 2, and becomes a generator by supplying rotational power with the shaft 4 as an input shaft.

[0019] Next, the stator core 21 according to this embodiment will be described in detail. As shown in Figure 2, the stator core 21 is provided with an annular back yoke 21a and a plurality of teeth 21b (48 in this embodiment) that protrude from the inner circumference 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 face the rotor 3. The stator core 21 is formed in a cylindrical shape by laminating steel plates, each having a back yoke 21a and a plurality of teeth 21b.

[0020] Between two adjacent teeth 21b of the multiple teeth 21b, core grooves (slots) 21c are formed for inserting the armature windings 23. Therefore, the stator 2 has multiple slots 21c between the rotor 3 and the back yoke 21a.

[0021] Furthermore, as shown in Figure 3, the cross-sectional shape of the teeth 21b may be formed to taper toward the center of the stator core 21, so that the cross-sectional shape of the slot 21c is rectangular. Preferably, the stator core 21 has a curved surface at the joint 21ab between each side of the two teeth 21b surrounding the slot 21c and the inner surface of the back yoke 21a.

[0022] The bobbin 22 is an insulator, manufactured by molding resin, fitted into the slot 21c, and has multiple (four in this embodiment) coil insertion holes 22a arranged along the radial direction of the stator core 21. The bobbin 22 insulates the multiple armature windings 23 from the stator core 21 (back yoke 21a and teeth 21b).

[0023] As shown in Figure 3, the bobbin 22 is provided with a plurality of coil insertion holes 22a and a plurality of side walls (a plurality of partition walls 22b, a back yoke side wall 22c, a slot opening side wall 22d, and two tooth side walls 22e).

[0024] The multiple (three in this embodiment) partition walls 22b are located between two adjacent coil insertion holes 22a and are insulating walls that suppress short circuits between the armature windings 23 inserted into the multiple coil insertion holes 22a.

[0025] As shown in Figure 3, the back yoke side wall 22c is the side wall closest to the back yoke 21a among the multiple side walls of the bobbin 22, and is an insulating wall that suppresses short circuits between the back yoke 21a and the armature winding 23. A first void hole 22ca is provided in the back yoke side wall 22c.

[0026] Furthermore, it is preferable that the first void 22ca is a through-hole that penetrates the stator core 21 in the axial direction. Also, it is preferable that the thickness t22c of the back yoke side wall 22c is greater than the thickness t22b of the partition wall 22b. In addition, it is preferable that resin is injected into the first void 22ca.

[0027] It is preferable that the width w22ca of the first void 22ca in the radial direction of the stator core 21 is greater than the thickness t22b of the partition wall 22b. Furthermore, it is preferable that the resin thickness t1 between the first void 22ca and the coil insertion hole 22aa that is closest to the first void 22ca among the plurality of coil insertion holes 22a is approximately the same as the thickness t22b of the partition wall.

[0028] Furthermore, it is preferable that the resin thickness t1 to t4 around the first void 22ca is approximately the same as the thickness t22b of the partition wall. In addition, it is preferable that the width w22ca of the first void 22ca in the radial direction of the stator core 21 is smaller than the width t22a of each of the multiple coil insertion holes 22a in the radial direction of the stator core 21.

[0029] Furthermore, it is preferable that the corner 22cb of the back yoke side wall 22c facing the joint portion 21ab formed in the slot 21c is chamfered with an R-chamfer that follows the curved surface of the joint portion 21ab.

[0030] The slot opening side wall 22d is the side wall of the bobbin 22 closest to the opening of the slot 21c. The two tooth side walls 22e are located between the multiple coil insertion holes 22a and the teeth 21b and are insulating walls that suppress short circuits between the armature windings 23 inserted into each of the multiple coil insertion holes 22a and the teeth 21b.

[0031] The bobbin 22 can be made from various resins, such as liquid crystalline resin, PPS resin, POE resin, aramid resin, polyimide resin, polyester resin, PE resin, PP resin, and epoxy resin. Two types of resins may also be used in combination. Furthermore, fillers such as inorganic fillers, organic fillers, inorganic fibers, and organic fibers may be mixed in.

[0032] The armature winding 23 is, for example, a flat rectangular wire with a flattened cross-sectional shape, inserted into each of the multiple coil insertion holes 22a, and wound around the multiple teeth 21b, for example, in a distributed winding manner.

[0033] (Effects / Actions) Figure 4 is a schematic diagram showing the magnetic circuit generated around the armature winding 23 inserted into a plurality of coil insertion holes 22a provided in the bobbin 122 of the comparative example.

[0034] When current flows through the armature winding 23a, a magnetic flux Φ23a of the magnetic path shown in Figure 4 is generated around the armature winding 23a, and when current flows through the armature winding 23b, a magnetic flux Φ23b of the magnetic path shown in Figure 4 is generated around the armature winding 23b.

[0035] Figure 5 is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding 23a of a rotating electric machine according to a comparative example, expressed using lumped parameters. As shown in Figure 5, 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 teeth 21b side, and a magnetic resistance R22b on the partition wall 22b side. If the magnetomotive force of the armature winding 23a is I, then the magnetic flux Φ23a is: Φ23a = I / (R21a + R21b × 2 + R22b) This is the result.

[0036] Figure 6 is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding 23b of a rotating electric machine according to a comparative example, expressed using lumped parameters. As shown in Figure 6, the magnetic circuit around the armature winding 23b has a magnetic resistance R21b on the teeth 21b side and a magnetic resistance R22b on the partition wall 22b side. If the magnetomotive force of the armature winding 23b is I, then the magnetic flux Φ23b is: Φ23b = I / ((R21b + R22b) × 2) This is the result.

[0037] Here, the magnetic resistances R21a and R21b are approximately equivalent because the magnetic back yoke 21a and teeth 21b form the magnetic path. On the other hand, the magnetic resistance R22b is approximately equivalent to air because the non-magnetic partition wall 22b forms the magnetic path. Therefore, the magnetic resistance R22b is 100 to 10,000 times greater than that of R21a and R21b, and the magnetic flux Φ23a is greater than the magnetic flux Φ23b. However, the magnetic flux Φ23a that passes through the back yoke 21a does not link with the rotor 3, and is therefore an inactive magnetic flux that does not contribute to the rotational torque of the rotor 3.

[0038] On the other hand, when the rotating electric machine 1 according to this embodiment is driven synchronously as a permanent magnet synchronous motor, the positional relationship between the multiple permanent magnets 33 of the rotor 3 and the multiple teeth 21b of the stator 2 changes continuously, causing the magnetic circuit within the motor to fluctuate. When magnetic saturation occurs in the teeth during fluctuations in the magnetic circuit, the inductance fluctuates nonlinearly, and the current flowing through the armature winding pulsates. If the current pulsation exceeds the control range of the control device, the pulsation becomes apparent, and the controllability of the motor deteriorates. In other words, if the inductance of the armature winding is large, the amount of fluctuation in current pulsation due to magnetic saturation becomes large, and the controllability of the motor deteriorates.

[0039] On the other hand, reducing the inductance allows for a reduction in the load angle, which is the phase difference between the terminal voltage and the no-load induced electromotive force. Therefore, for example, it is possible to widen the effective load range when performing sensorless control, thereby improving the controllability of the motor.

[0040] Figure 7 is a schematic diagram showing the magnetic circuit generated around the armature winding 23 inserted into a plurality of coil insertion holes 22a provided in the bobbin 22 according to this embodiment. When current flows through the armature winding 23a, a magnetic flux Φ23a of the magnetic path shown in Figure 7 is generated around the armature winding 23a, and when current flows through the armature winding 23b, a magnetic flux Φ23b of the magnetic path shown in Figure 7 is generated around the armature winding 23b.

[0041] Figure 8 is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding 23a of the rotating electric machine 1 according to this embodiment, using lumped parameters. As shown in Figure 8, the magnetic circuit around the armature winding 23a has a magnetic resistance R21b on the teeth 21b side and a magnetic resistance R22b on the partition wall 22b side.

[0042] If the magnetomotive force of the armature winding 23a is I, then the magnetic flux Φ23a is: Φ23a = I / ((R21b + R22b) × 2) This is the result.

[0043] Figure 9 is a magnetic circuit diagram representing the magnetic circuit generated around the armature winding 23b of the rotating electric machine 1 according to this embodiment, using lumped parameters. As shown in Figure 9, the magnetic circuit around the armature winding 23b has a magnetic resistance R21b on the teeth 21b side and a magnetic resistance R22b on the partition wall 22b side. If the magnetomotive force of the armature winding 23b is I, then the magnetic flux Φ23b is, Φ23b = I / ((R21b + R22b) × 2) This is the result.

[0044] In this embodiment, the magnetic circuit generated around the armature winding 23a of the rotating electric machine 1 does not include the magnetic resistance R21a on the back yoke 21a side, so the magnetic flux Φ23a is approximately equal to the magnetic flux Φ23b.

[0045] On the other hand, since the magnitude of the magnetic flux Φ with respect to the magnetomotive force I represents the inductance of the armature winding 23, the rotating electric machine 1 according to this embodiment can have a smaller inductance than the rotating electric machine according to the comparative example.

[0046] The bobbin 22 allows the coil insertion hole 22aa closest to the back yoke 21a among the multiple coil insertion holes 22a arranged radially along the stator core 21 to be moved away from the back yoke 21a by the first air gap hole 22ca. This prevents the magnetic circuit around the armature winding 23a inserted in the coil insertion hole 22aa from including the magnetic resistance R21a on the back yoke 21a side, similar to the magnetic circuit around the armature winding 23 inserted in the other coil insertion holes 22a. As a result, the magnetic flux Φ1 is reduced, the inductance is reduced, and the controllability of the motor can be improved. Thus, by moving the armature winding 23 away from the back yoke 21a, the controllability of the motor can be improved.

[0047] In other words, the rotating electric machine 1 of this embodiment comprises a rotor 3, a stator core 21 having a plurality of slots 21c between the rotor 3 and the back yoke 21a, a resin bobbin 22 having a plurality of coil insertion holes 22a arranged along the radial direction of the stator core 21 and fitted into the slots 21c, and a first void hole 22ca provided in the back yoke side wall 22c, which is the side wall of the bobbin 22 closest to the back yoke 21a.

[0048] By providing a first air gap 22ca in the back yoke side wall 22c, which is the side wall of the bobbin 22 closest to the back yoke 21a, the distance between the armature winding 23a and the back yoke 21a can be secured. Therefore, the increase in inductance can be suppressed, and the controllability of the rotating electric machine 1 can be improved.

[0049] Furthermore, by providing the first void 22ca, the resin thickness t1 to t4 of the back yoke side wall 22c is prevented from becoming excessively larger than the resin thickness of the side walls of other parts. This prevents localized resin accumulation during resin molding of the bobbin 22, thus suppressing the occurrence of molding defects in the bobbin 22. In other words, the rotating electric machine 1 of this embodiment can suppress a decrease in the controllability of the rotating electric machine 1 and suppress molding defects in the bobbin 22.

[0050] Furthermore, in the bobbin 22 of this embodiment, it is preferable that the first void hole 22ca provided in 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. This facilitates the molding of the first void hole 22ca and suppresses unevenness in resin pressure when resin molding the bobbin 22, thereby suppressing the occurrence of molding defects such as cracks.

[0051] Furthermore, in the bobbin 22 of this embodiment, it is preferable that the back yoke side wall 22c is thicker than the partition wall 22b located between two adjacent coil insertion holes 22a among the multiple coil insertion holes 22a. This allows the inductance to be reduced compared to when the thickness t22c of the back yoke side wall 22c is less than or equal to the thickness t22b of the partition wall 22b, thereby improving the controllability of the motor.

[0052] Furthermore, in this embodiment, it is preferable that the width w22ca of the first void hole 22ca in the radial direction of the stator core 21 is greater than the thickness t22b of the partition wall 22b. This allows the thickness t22c of the back yoke side wall 22c in the radial direction of the stator core 21 to be greater than the thickness t22b of the partition wall 22b, and also allows the resin thickness t1 to t4 around the first void hole 22ca to be reduced. As a result, the inductance can be reduced, suppressing a decrease in the controllability of the rotating electric machine 1, and molding defects of the bobbin 22 can be suppressed by reducing the resin thickness t1 to t4 around the first void hole 22ca.

[0053] Furthermore, it is preferable that the resin thickness t1 between the first void 22ca and the coil insertion hole 22aa that is closest to the first void 22ca among the plurality of coil insertion holes 22a is substantially the same as the thickness t22b of the partition wall 22b. This suppresses uneven distribution of resin pressure when resin molding the bobbin and further suppresses the occurrence of molding defects such as cracks.

[0054] Furthermore, it is preferable that the resin thickness t1 to t4 around the first void 22ca in this embodiment is approximately the same as the thickness t22b of the partition wall 22b. This further suppresses uneven distribution of resin pressure when molding the bobbin, thereby further suppressing the occurrence of molding defects such as cracks.

[0055] Furthermore, it is preferable that the width w22ca of the first void hole 22ca in the radial direction of the stator core 21 in this embodiment is smaller than the width t22a of each of the multiple coil insertion holes 22a in the radial direction of the stator core 21. This makes it possible to reduce the width t22c of the back yoke side wall 22c in the radial direction of the stator core 21, thereby suppressing a decrease in the space factor of the armature winding 23 wound around the teeth 21b.

[0056] Furthermore, it is preferable that the joint portion 21ab between each side of the two teeth 21b surrounding the slot 21c in this embodiment and the inner surface of the back yoke 21a is curved. This allows magnetic flux to flow more easily at the joint portion 21ab, reducing magnetic resistance to the flux linkage and thus reducing magnetic loss.

[0057] Furthermore, it is preferable to inject resin into the first void 22ca of this embodiment, thereby improving the strength of the bobbin 22.

[0058] (Second Embodiment) Figure 10 is a partially enlarged cross-sectional view of a rotating electric machine according to a second embodiment of the present invention. The difference between this embodiment and the first embodiment is that a back yoke-side opening 22ce, which is a slit extending in the axial direction of the stator core 21, is provided in the resin wall 22cc between the first void hole 22ca and the back yoke 21a.

[0059] As a result, in the mold for resin molding the bobbin 222, the through-hole forming projection provided in the mold to form the first void hole 22ca is connected to the outer wall of the mold via the mold portion for forming the back yoke side opening 22ce. Therefore, the bending and vibration that occurs in the through-hole forming projection due to the pressure of the resin injected into the mold during injection molding of the bobbin 222 is suppressed, thereby suppressing molding defects.

[0060] Furthermore, in order to prevent a decrease in the strength of the resin wall 22cc, it is preferable that the back yoke side opening 22ce is provided only in a part of the axial direction of the stator core 21. In this case, it is preferable that the mold portion for forming the back yoke side opening 22ce is provided on the tip side of the through-hole forming projection in order to efficiently suppress the deflection and vibration that occurs in the through-hole forming projection of the mold. For this reason, it is preferable that the back yoke side opening 22ce is formed on the tip side of the through-hole forming projection of the mold.

[0061] (Third embodiment) Figure 11 is a partially enlarged cross-sectional view of a rotating electric machine according to the third embodiment of the present invention. The difference between this embodiment and the second embodiment is that a second void hole 22da is provided in the side wall of the bobbin 322 that is closest to the opening of the slot 21c (slot opening side wall 22d).

[0062] As a result, the resin thickness t5~t8 around the second void 22da of the slot opening side wall 22d is reduced, which suppresses localized resin accumulation on the slot opening side wall 22d during resin molding of the bobbin 322. Therefore, the occurrence of molding defects in the bobbin 22 can be further suppressed.

[0063] Furthermore, it is preferable that the thickness of the resin around the second void 22da, t5 to t8, is approximately the same as the thickness t22b of the partition wall 22b. This further suppresses uneven distribution of resin pressure when molding the bobbin 322, and further suppresses molding defects such as cracks.

[0064] Furthermore, it is preferable that resin is injected into the second void 22da. This can improve the strength of the bobbin 322.

[0065] (Fourth Embodiment) Figure 12 is a partially enlarged cross-sectional view of a rotating electric machine according to the fourth embodiment of the present invention. The difference between this embodiment and the third embodiment is that a slot opening side opening 22de, which is a slit extending in the axial direction of the stator core 21, is provided in the resin wall 22dc between the second void hole 22da and the opening of the slot 21c.

[0066] As a result, in the mold for resin molding the bobbin 422, the through-hole forming projection provided in the mold to form the second void hole 22da is connected to the outer wall of the mold via the projection for forming the slot opening side opening 22de. Therefore, the bending and vibration that occurs in the through-hole forming projection due to the pressure of the resin injected into the mold during injection molding of the bobbin 422 is suppressed, thereby suppressing molding defects.

[0067] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations.

[0068] Furthermore, embodiments of the present invention may also be as follows. In the rotating electric machine 1 described above, the case with 8 poles and 48 slots is shown, but the invention is not limited to this, and any 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.

[0069] Furthermore, the above describes the use of rectangular or segmented (C) shaped ferrite magnets, neodymium magnets, and samarium-cobalt magnets as permanent magnets 33. However, the invention is not limited to this form, and other magnets and other shapes may be used. In addition, the magnet insertion hole 32 may contain not only one magnet, but also multiple permanent magnets 33 inserted in the axial, circumferential, or radial directions of the stator 2.

[0070] Furthermore, in the above-described embodiment, the cross-sectional shape of the teeth 21b is formed to taper toward the center of the stator core 21, so that the cross-sectional shape of the slot 21c is rectangular. However, the embodiment is not limited to this, and for example, the cross-sectional shape of the teeth 21b may be rectangular, and the cross-sectional shape of the slot 21c may taper toward the center of the stator core 21. Alternatively, the tip of the teeth 21b may spread out in the circumferential direction of the stator core 21, and the cross-sectional shape of the teeth 21b may be T-shaped.

[0071] Furthermore, in the above embodiment, a stator core 21 was shown in which a steel plate having a back yoke 21a and a plurality of teeth 21b integrally provided was laminated. However, the invention is not limited to this, and the plurality of teeth 21b and the back yoke 21a may be made from different steel plates, and a plurality of laminated teeth 21b may be assembled and fixed to the laminated back yoke 21a.

[0072] Furthermore, while it is preferable to use flat rectangular wire for the armature winding 23 in order to increase the winding space factor, it is not limited to this, and round wire or stranded wire may also be used, for example. When round wire or stranded wire is used for the armature winding 23, it is preferable to deform the shape of the coil insertion hole 22a according to the cross-sectional shape of the armature winding 23. In addition, it is preferable for the armature winding 23 to be an electrical conductor mainly composed of copper coated with an insulating film (for example, varnish or engineering plastic). [Explanation of Symbols]

[0073] 1…Rotating electric machine, 2…Stator, 3…Rotor, 21…Stator core, 21a…Back yoke, 21aa…Inner side of back yoke, 21ab…Joint, 21b…Teeth, 21ba…Side of teeth, 21c…Slot, 22,122,222,322,422…Bobbin, 22a…Coil insertion hole, 22b…Partition wall, 22c…Back yoke side wall, 22ca…First void hole, 22cc…Resin wall, 22ce…Back yoke side opening, 22d…Slot opening side wall, 22da…Second void 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. Rotor and A stator core having multiple slots between the rotor and the back yoke, A resin bobbin fitted into the slot has a plurality of coil insertion holes arranged along the radial direction of the stator core, A rotating electric machine characterized by comprising a first void hole provided in the back yoke side wall, which is the side wall of the bobbin closest to the back yoke.

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

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

4. A rotating electric machine according to claim 3, A rotating electric machine characterized in that the width of the first void in the radial direction of the stator core is greater than the thickness of the partition wall.

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

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

7. A rotating electric machine according to claim 1, A rotating electric machine characterized in that the width of the first void in the radial direction of the stator core is smaller than the width of each of the plurality of coil insertion holes in the radial direction of the stator core.

8. A rotating electric machine according to claim 1, The aforementioned slot is formed between two teeth that are adjacent in the circumferential direction among a plurality of teeth that protrude from the back yoke toward the center of the stator core, A rotating electric machine characterized in that the joint between each of the two teeth surrounding the slot and the inner surface of the back yoke is a curved surface.

9. A rotating electric machine according to claim 1, A rotating electric machine characterized in that resin is injected into the first void.

10. A rotating electric machine according to claim 1, A rotating electric machine characterized in that a slit extending in the axial direction of the stator core is provided in the resin wall between the first void and the back yoke.

11. A rotating electric machine according to claim 1, A rotating electric machine characterized in that a second void hole is provided in the side wall of the bobbin that is closest to the opening of the slot.

12. A rotating electric machine according to claim 11, A rotating electric machine characterized in that the thickness of the resin surrounding the second void is substantially the same as the thickness of the partition wall located between two adjacent coil insertion holes among the plurality of coil insertion holes.

13. A rotating electric machine according to claim 11, A rotating electric machine characterized in that resin is injected into the second void.

14. A rotating electric machine according to claim 11, A rotating electric machine characterized in that a slit-shaped second opening extending in the axial direction of the stator core is provided in the resin wall between the second void and the opening of the slot.

15. An industrial machine characterized by comprising the rotating electric machine described in claim 1.

Images