Rotating electric machine

Abstract

A rotating electrical machine according to the present invention is provided with: a stator (10) having a stator core (11) in which a plurality of divided cores (12) divided in the circumferential direction are combined into an annular shape, and a coil (16) wound in a distributed manner around the stator core (11); and a rotor (30) capable of rotating with respect to the stator (10), in which magnetic poles having P pole pairs are arranged on a rotor core (31), the split core (12) has a core back (13), a plurality of teeth (14) protruding in the inner circumferential direction from the core back (13), and winding slots (15), the number of teeth (14) of the split core (12) is equal, and P < N < 2P is satisfied, where N is the number of split cores of the split core (12).

Description

Technical Field

[0001] The present application relates to a rotating electric machine. Background Art

[0002] In order to reduce the material cost of an electric motor, a stator core formed by combining segmented cores divided in the circumferential direction, which can improve the yield of electromagnetic steel sheets, is widely used. If the stator core is finely divided in the circumferential direction, the yield of the electromagnetic steel sheets will also increase. Therefore, from the viewpoint of reducing the material cost, it is preferable to increase the number of segments of the stator core. However, if a segmented core with a large number of segments is used, the manufacturing cost increases due to the increase in the number of components, and the assembly difficulty increases. Therefore, an electric motor using a segmented core with a small number of segments is being studied.

[0003] An electric motor that reduces the material cost by utilizing the remaining area inside the rotor and co-stamping the segmented cores is disclosed (for example, Patent Document 1). Prior Art Documents Patent Documents

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-186227 Summary of the Invention Technical Problem to be Solved by the Invention

[0005] On the other hand, when the same harmonic components are included in the magnetomotive force and permeance, an axial voltage is generated on the shaft of the rotor. In an actual machine, when the segmented cores are combined, it is difficult to prevent minute gaps from being generated between the segmented cores, which thus causes permeance harmonics and sometimes generates an axial voltage. In the case of an electric motor in which the rotor is supported by a mechanical bearing, since an axial voltage causes discharge between the shaft and the bearing, which leads to electrical erosion of the bearing and becomes a main cause of vibration and noise, a design for reducing the axial voltage is required. Therefore, in an electric motor using a segmented core, it is important to pay attention to the combination of the number of poles of the rotor and the number of segments of the stator. In addition, even when gaps are generated between the segmented cores, the combination of the number of poles of the rotor and the number of segments of the stator where no axial voltage is generated is when the number of segments is an integer multiple of the number of poles, but the torque ripple may increase.

[0006] In Patent Document 1, there is no description of axial voltage and torque ripple. In the disclosed example, there are technical problems of axial voltage generated by the gaps between the segmented cores and increased torque ripple without axial voltage generation.

[0007] The present application discloses a technology for solving the above problems, and an object thereof is to provide a rotating electric machine capable of reducing the material cost, improving the manufacturability, reducing the axial voltage, and suppressing the torque ripple. Technical Solution for Solving the Technical Problem

[0008] The rotating electrical machine disclosed in the present application includes: a stator having a stator core formed by combining a plurality of segmented cores circumferentially segmented into an annular shape, and coils wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located on the central axis of the stator, with magnetic poles having a pole pair number of P disposed on the rotor core. In this rotating electrical machine, the segmented core has an arcuate core back and a plurality of teeth protruding from the core back toward the inner circumferential direction, with winding slots between the teeth, and the number of teeth is equal. If the number of segments of the segmented core is set as N, then P < N < 2P. The rotating electrical machine disclosed in the present application includes: a stator having a stator core formed by combining a plurality of segmented cores circumferentially segmented into an annular shape, and coils wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located on the central axis of the stator, with magnetic poles having a pole pair number of P disposed on the rotor core. In this rotating electrical machine, the segmented core has an arcuate core back and a plurality of teeth protruding from the core back toward the inner circumferential direction, with winding slots between the teeth, and the number of teeth is equal. If the number of segments of the segmented core is set as N, then 2P < N < 4P. Advantages of the Invention

[0009] According to the rotating electrical machine disclosed in the present application, a rotating electrical machine can be obtained that can reduce material costs, improve manufacturability, and at the same time reduce shaft voltage and suppress torque ripple. Description of the Drawings

[0010] Figure 1 It is a cross-sectional view of a 6-segment 8-pole 48-slot double V-shaped buried magnet type motor of the rotating electrical machine of Embodiment 1. Figure 2 It is a cross-sectional view of a segmented core constituting the stator core of the rotating electrical machine of Embodiment 1. Figure 3 It is a perspective view of the stator core of the rotating electrical machine of Embodiment 1. Figure 4 It is analysis data of the maximum value of the shaft voltage with the number of segments of the stator core of the rotating electrical machine of Embodiment 1 as a parameter. Figure 5 It is analysis data of the torque ripple amplitude with the number of segments of the stator core of the rotating electrical machine of Embodiment 1 as a parameter. Figure 6 It is a cross-sectional view of a 12-segment 8-pole 48-slot double V-shaped buried magnet type motor as a modified example of the rotating electrical machine of Embodiment 1. Figure 7 It is a cross-sectional view of a 6-segment 8-pole 72-slot double V-shaped buried magnet type motor as a modified example of the rotating electrical machine of Embodiment 1. Figure 8 It is a cross-sectional view of a 12-segment 8-pole 96-slot double-V buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 9 It is a cross-sectional view of an 8-segment 12-pole 72-slot double-V buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 10 It is a cross-sectional view of a 24-segment 16-pole 96-slot double-V buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 11 It is a cross-sectional view of a 6-segment 8-pole 48-slot flat magnet buried type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 12 It is a cross-sectional view of a 12-segment 8-pole 48-slot single-V buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 13 It is a cross-sectional view of a 6-segment 8-pole 48-slot triple-V buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 14 It is a cross-sectional view of a 12-segment 8-pole 48-slot ▽-type buried magnet type motor, which is a modified example of the rotating electrical machine in Embodiment 1. Figure 15 It is a cross-sectional view of the segmented core that constitutes the stator core of the rotating electrical machine in Embodiment 2. Figure 16 It is a cross-sectional view of a 6-segment 8-pole 48-slot double-V buried magnet type motor of the rotating electrical machine in Embodiment 2. Figure 17 It is a perspective view of a 30-degree rotated 4-pole rotating laminated stator core of the rotating electrical machine in Embodiment 3. Figure 18 It is an explanatory diagram of the rolling direction and tooth direction in the cross-sectional view of the segmented core of the rotating electrical machine in Embodiment 4. Figure 19 It is an explanatory diagram of the tooth numbers in the cross-sectional view of the segmented core of the rotating electrical machine in Embodiment 4. Figure 20 It is an explanatory diagram of the tooth direction component of the rolling direction magnetic characteristics of the teeth at the same circumferential position in each section of the stator core in the comparative example of the rotating electrical machine in Embodiment 4. Figure 21 It is a perspective view of the stator core of the rotating electrical machine in Embodiment 4. Figure 22 It is an explanatory diagram of the tooth direction component of the rolling direction magnetic characteristics of the teeth at the same circumferential position in each section of the stator core of the rotating electrical machine in Embodiment 4. Figure 23It is a cross-sectional view of a segmented core that constitutes the stator core of the rotating electrical machine according to Embodiment 5. Figure 24 It is a cross-sectional view of a 6-segment 8-pole 48-slot double V-shaped buried magnet type motor obtained by dividing the stator core of the rotating electrical machine according to Embodiment 5 at the center of the teeth. Figure 25 It is a perspective view of a 30-degree rotated 6-pole rotating laminated stator core of the rotating electrical machine according to Embodiment 5. Figure 26 It is a cross-sectional view of a 12-segment 8-pole 48-slot double V-shaped buried magnet type motor obtained by dividing at the center of the teeth as a modified example of the rotating electrical machine according to Embodiment 5. Figure 27 It is a cross-sectional view of a segmented core that constitutes the stator core of the rotating electrical machine according to Embodiment 6. Figure 28 It is a cross-sectional view of a 4-segment 6-pole 54-slot double V-shaped buried magnet type motor obtained by dividing the core back and teeth of the rotating electrical machine according to Embodiment 6. Figure 29 It is a perspective view of a 45-degree rotated 2-pole rotating laminated stator core of the rotating electrical machine according to Embodiment 6. Detailed Embodiments

[0011] Embodiment 1. Embodiment 1 is a rotating electrical machine including: a stator having a stator core formed by combining a plurality of segmented cores divided in the circumferential direction into a circular ring shape, and coils wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located at the center axis of the stator, and magnetic poles with a pole pair number of P are arranged on the rotor core. In this rotating electrical machine, the segmented core has an arc-shaped core back and a plurality of teeth protruding from the core back toward the inner circumferential direction, there are winding slots between the teeth, and the number of teeth is equal. If the number of segments of the segmented core is set to N, then P < N < 2P or 2P < N < 4P is satisfied.

[0012] Hereinafter, regarding the rotating electrical machine of Embodiment 1, Figure 1 which is a cross-sectional view of a 6-segment 8-pole 48-slot double V-shaped buried magnet type distributed winding motor, Figure 2 which is a cross-sectional view of a segmented core constituting the stator core, Figure 3 which is a perspective view of the stator core, Figure 4 which is analysis data of the maximum value of the shaft voltage with the number of segments of the stator core as a parameter, Figure 5 which is analysis data of the torque ripple amplitude with the number of segments of the stator core as a parameter, Figures 6 - 14 and which is a cross-sectional view of a buried magnet type distributed winding motor as a modified example of the rotating electrical machine will be described. In addition, in the respective drawings, the same or equivalent parts are denoted by the same reference numerals, and redundant descriptions are omitted.

[0013] In the following description, the direction of the rotation axis is defined as the axial direction (Z), the direction of the rotation axis center (the direction from the outer circumference of the stator toward the rotation axis center) is defined as the radial direction (R), and the direction along the rotation direction centered on the rotation axis is defined as the circumferential direction (P), which are also appropriately described in the drawings. In addition, in the present application, as the rotating electric machine, an interior permanent magnet type distributed winding motor is assumed, and thus, in the description, the interior permanent magnet type distributed winding motor is appropriately described as the interior permanent magnet type motor.

[0014] First, based on Figure 1 which is a cross-sectional view obtained by cutting the entire structure of the rotating electric machine 100 of Embodiment 1 in a plane perpendicular to the axial direction of the rotating electric machine 100, Figure 2 which is a cross-sectional view of the segmental core constituting the stator core, Figure 3 and which is a perspective view of the stator core, the rotating electric machine 100 is coaxially disposed on the inner peripheral side of the stator 10 and the stator 10, and is composed of a rotor 30 that can rotate relative to the stator 10. The stator 10 includes a stator core 11, teeth 14, and coils 16. The stator core 11 is composed of segmental cores 12 having a segmentation number N ( Figure 1 where the segmentation number N is 6 in ), and has a core back 13, teeth 14, and winding slots 15.

[0015] First, based on Figure 2 the basic segmental core 12 of the stator 10 will be described. The segmental core 12 constituting the stator core 11 of the rotating electric machine 100 of Embodiment 1 is formed by laminating a plurality of electromagnetic steel sheets, and is composed of a plurality of teeth 14 protruding from the core back 13 on the arc toward the central axis in the inner circumferential direction, and winding slots 15 which are regions between adjacent teeth 14. Moreover, the segmental core 12 is divided from the circumferential center portion of the winding slot 15 to the core back 13 (core back division), eight teeth 14 are arranged in the circumferential direction, and the arc angle of the segmental core 12 is 60 degrees.

[0016] Return Figure 1 , and the rotating electric machine 100 will be described. The stator core 11 is formed by Figure 2The six segmented cores 12 described in [description] are arranged in a circular ring, and the number of teeth 14 of each segmented core 12 is equal, with 48 teeth 14 evenly distributed in the circumferential direction. In addition, in the stator core 11 of Embodiment 1, in the abutting portions formed between the segmented cores 12 arranged adjacent to each other, a minute gap 21 is formed between the segmented cores 12. In the stator core 11 of Embodiment 1, within the range of manufacturing deviation, the gap 21 is formed at most positions of the abutting portions between the segmented cores 12. In addition, the widths and sizes of the gaps 21 are different from each other in the abutting portions between the segmented cores 12.

[0017] In addition, coils 16 are accommodated in the respective winding slots 15, and the coils 16 are connected in series with the coils 16 accommodated in six adjacent winding slots 15 in the circumferential direction.

[0018] The rotor 30 is composed of a shaft 32 located on the central axis of the stator 10, an annular rotor core 31 fixed to the shaft 32, and permanent magnets 33 arranged in a double-V shape with eight poles in magnet slots 34 provided on the rotor core 31 (double-V buried magnet type).

[0019] As Figure 3 shown, the stator core 11 is configured such that the segmentation positions are the same in all axial cross-sections. In this way, an 8-pole 48-slot distributed winding motor using six segmented cores is configured.

[0020] Next, using Figure 4 、 Figure 5 the electromagnetic field analysis results, the shaft voltage and torque ripple generated by the rotating electrical machine and the method for suppressing them will be described. Figure 4 is the analysis result of the maximum value of the shaft voltage when the stator core 11 is equally divided (0 division, 2 division, 3 division, 4 division, 6 division, 8 division, 12 division, 16 division, 24 division, 48 division) at the core back 13 in an 8-pole 48-slot distributed winding motor, and a gap 21 of 25 μm is generated between the segmented cores 12. Among them, the maximum value of the shaft voltage is normalized by the maximum value of the shaft voltage at the time of 6 division. Figure 5 is the analysis result of the torque ripple amplitude when the stator core 11 is equally divided (0 division, 2 division, 3 division, 4 division, 6 division, 8 division, 12 division, 16 division, 24 division, 48 division) at the core back 13 in an 8-pole 48-slot distributed winding motor, and a gap 21 of 25 μm is generated between the segmented cores 12. Among them, the torque ripple amplitude is normalized by the torque ripple amplitude at the time of 6 division.

[0021] The shaft voltage, which is one of the problems of the present application, is known to be generated when there are the same components in the magnetomotive force harmonics and the permeability harmonics. In a motor in which a segmented core 12 divided in the circumferential direction is used in the stator core 11, minute gaps 21 are generated between adjacent segmented cores, which causes the permeability harmonics. In an 8-pole 48-slot buried magnet type motor, when gaps 21 are respectively generated between the segmented cores 12, shaft voltages are generated when segmented into 2, 3, 4, 6, and 12 segments. In addition, since the permeability harmonics containing the same components as all the magnetomotive force harmonics are included in the 2-segment and 4-segment cases, it is expected that the shaft voltage will increase.

[0022] As Figure 4 shown, shaft voltages are generated when segmented into 2, 3, 4, 6, and 12 segments. Particularly in the 2-segment and 4-segment cases, since the permeability harmonics containing the same components as all the magnetomotive force harmonics exist, it can be confirmed that the shaft voltage increases.

[0023] In addition, when the stator core 11 is segmented into an integer multiple of the number of poles, no shaft voltage is generated. However, when using segmented cores 12 in an integer multiple of the number of poles and gaps 21 are generated between the segmented cores 12, the torque ripple may increase.

[0024] As Figure 5 shown, it can be seen that in the 8-segment buried magnet type motor, the torque ripple is increased by about 5% compared to the 6-segment buried magnet type motor of the rotating electrical machine 100 in Embodiment 1. In addition, in the 16-segment, 24-segment, and 48-segment buried magnet type motors, which are integer multiples of the number of poles, the torque ripple also increases compared to the 6-segment buried magnet type motor.

[0025] Based on the above results, in the 8-pole 48-slot buried magnet type motor, the suitable number of segments judged from both low shaft voltage and low torque ripple is 3, 6, and 12. The number of segments larger than the number of pole pairs P, that is, the 6-segment motor in Embodiment 1, and the 12-segment motor as Figure 6 shown later, can fully exhibit the effect of reducing the material cost of the segmented core 12. These numbers of segments satisfy the relationship of P < N < 2P (Condition A) or 2P < N < 4P (Condition B).

[0026] As described above, in Embodiment 1, by forming the segmented core 12 of the rotating electrical machine 100, the yield rate of the electromagnetic steel sheet of the segmented core 12 is improved, so that the material cost can be reduced. Furthermore, by using the segmented core 12 with a small number of segments, the number of components can be reduced and the manufacturability can be improved. Moreover, since the relationship between the number of pole pairs and the number of divisions satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), it is possible to reduce the shaft voltage generated by the combination of the number of poles and the number of divisions of the stator core 11, and it is also possible to suppress the torque ripple generated by the number of poles and the number of divisions of the stator core 11. In addition, through the core back division structure, it is possible to suppress the strain of the teeth 14, reduce the manufacturing strain of the entire buried magnet type motor, and reduce the motor loss.

[0027] Here, the relationship between the number of divisions N of the divided core 12 and the number of winding slots S will be described. The circumferential division number N of the stator core 11 is a factor of S, whereby it is possible to make all the shapes of the divided cores 12 constituting the stator core 11 the same, and thus it is possible to reduce the manufacturing cost of the divided cores 12.

[0028] Next, regarding the modified example of the 6 - equal - division 8 - pole 48 - slot double V - shaped buried magnet type distributed winding motor described in Embodiment 1, the relationship with P < N < 2P (Condition A) and 2P < N < 4P (Condition B) will also be described. In addition, in each figure, in order to distinguish from Figure 2 the rotating electrical machine (6 - equal - division 8 - pole 48 - slot double V - shaped buried magnet type distributed winding motor) 100, the reference numerals are set to 101, etc.

[0029] Figure 6 is a cross - sectional view of an 8 - pole 48 - slot double V - shaped buried magnet type distributed winding motor (rotating electrical machine 101) in which the stator core 11 is divided into 12 equal parts in the circumferential direction by the core back 13. In this example, 2P < N < 4P (Condition B) is satisfied. Figure 7 is a cross - sectional view of an 8 - pole 72 - slot double V - shaped buried magnet type distributed winding motor (rotating electrical machine 102) in which the stator core 11 is divided into 6 equal parts in the circumferential direction by the core back 13. In this example, P < N < 2P (Condition A) is satisfied. Figure 8 is a cross - sectional view of an 8 - pole 96 - slot double V - shaped buried magnet type distributed winding motor (rotating electrical machine 103) in which the stator core 11 is divided into 12 equal parts in the circumferential direction by the core back 13. In this example, 2P < N < 4P (Condition B) is satisfied. Figure 9 is a cross - sectional view of a 12 - pole 72 - slot double V - shaped buried magnet type distributed winding motor (rotating electrical machine 104) in which the stator core 11 is divided into 8 equal parts in the circumferential direction by the core back 13. In this example, P < N < 2P (Condition A) is satisfied. Figure 10This is a cross-sectional view of a 16-pole 96-slot double V-shaped buried magnet type distributed winding motor (rotating electrical machine 105) in which the stator core 11 is circumferentially divided into 24 equal parts by the core back 13. In this example, 2P < N < 4P (Condition B) is satisfied.

[0030] Figure 11 This is a cross-sectional view of an 8-pole 48-slot flat magnet buried type distributed winding motor (rotating electrical machine 106) in which the stator core 11 is circumferentially divided into 6 equal parts by the core back 13. In this example, P < N < 2P (Condition A) is satisfied. Figure 12 This is a cross-sectional view of an 8-pole 48-slot single V-shaped buried magnet type distributed winding motor (rotating electrical machine 107) in which the stator core 11 is circumferentially divided into 12 equal parts by the core back 13. In this example, 2P < N < 4P (Condition B) is satisfied. Figure 13 This is a cross-sectional view of an 8-pole 48-slot triple V-shaped buried magnet type distributed winding motor (rotating electrical machine 108) in which the stator core 11 is circumferentially divided into 6 equal parts by the core back 13. In this example, P < N < 2P (Condition A) is satisfied. Figure 14 This is a cross-sectional view of an 8-pole 48-slot ▽-shaped buried magnet type distributed winding motor (rotating electrical machine 109) in which the stator core 11 is circumferentially divided into 12 equal parts by the core back 13. In this example, 2P < N < 4P (Condition B) is satisfied.

[0031] Here, the Figures 6 - 14 various buried magnet type distributed winding motors of the modified example are summarized. Figure 6 This is an 8-pole 48-slot distributed winding motor using a 12-segment core, but 2P < N < 4P (Condition B) is satisfied, achieving the same effect as the rotating electrical machine of Embodiment 1. In addition, as Figures 7 - 10 shown, even when the combination of the number of pole pairs and the number of slots is different, if the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effect can be achieved. In addition, as Figures 11 - 14 shown, even for different buried magnet type rotor structures, if the above relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effect as the rotating electrical machine of Embodiment 1 can be achieved. Furthermore, although not shown, even for surface-mounted type and winding excitation structures, as long as the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effect as the rotating electrical machine of Embodiment 1 can be obtained.

[0032] In addition, when the gaps 21 formed at the abutting portions between the mutually adjacent segmented cores 12, which were described as the structure of the stator core 11 in Embodiment 1, are formed to have different widths and sizes from each other, by setting the number of segments to a small number of segments that satisfies P < N < 2P (Condition A), it is possible to reduce the magnetic permeability harmonics generated due to the deviation of the gaps 21, and it is possible to more effectively reduce the shaft voltage.

[0033] As described above, the rotating electric machine of Embodiment 1 includes: a stator having a stator core formed by combining a plurality of segmented cores divided in the circumferential direction into an annular shape, and a coil wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located at the center axis of the stator, and magnetic poles with a pole pair number of P are arranged on the rotor core. In this rotating electric machine, the segmented core has an arc-shaped core back portion and a plurality of teeth protruding from the core back portion toward the inner circumferential direction, and there are winding slots between the teeth, and the number of teeth is equal. If the number of segments of the segmented core is set to N, then P < N < 2P or 2P < N < 4P is satisfied. Therefore, in Embodiment 1, a rotating electric machine can be obtained that can reduce material costs, improve manufacturability, while reducing the shaft voltage and suppressing torque ripple.

[0034] Embodiment 2. Embodiment 2 is a structure in which convex portions and concave portions for embedding are provided at the abutting portions of the segmented cores, and grooves are provided at the outer peripheral portion.

[0035] Regarding the rotating electric machine of Embodiment 2, based on Figure 15 which is a cross-sectional view of the segmented core that constitutes the stator core, and Figure 16 which is a cross-sectional view of a 6-segment 8-pole 48-slot double V-shaped buried magnet type motor, the description will be centered on the differences from Embodiment 1. In Embodiment 2's Figure 15 , Figure 16 the same reference numerals are added to the parts that are the same as or equivalent to those in Embodiment 1. In addition, in order to distinguish from the rotating electric machine 100 and the segmented core 12 of Embodiment 1, they are designated as the rotating electric machine 200 and the segmented core 212.

[0036] As Figure 15 shown, the segmented core 212 that constitutes the stator core 11 of the rotating electric machine 200 of Embodiment 2 is formed by laminating a plurality of electromagnetic steel sheets, and is composed of a plurality of teeth 14 protruding from the core back portion 13 on the arc toward the center axis along the inner circumferential direction, and a winding slot 15 as a region between the adjacent teeth 14. The segmented core 212 is segmented from the circumferential central portion of the winding slot 15 to the core back 13 (core back segmentation). Moreover, a convex portion 23 is provided on one side of the abutting portion of the segmented core 212, a concave portion 24 is provided on the other side, and a groove 22 is provided on the outer peripheral portion. Eight teeth 14 are arranged in the circumferential direction, and the arc angle of the segmented core 212 is 60 degrees.

[0037] In Figure 16 the embedded magnet type motor of the rotating electric machine 200 as the second embodiment is composed of a stator 10 and a rotor 30 coaxially arranged on the inner peripheral side of the stator 10 and capable of rotating relative to the stator 10. The stator 10 includes a stator core 11, teeth 14, and coils 16. The stator core 11 is formed by arranging six of the segmented cores 212 described in Figure 15 in a circular ring shape, and 48 teeth 14 are equally formed in the circumferential direction. The coils 16 are connected in series with the coils 16 housed in six adjacent winding slots 15 in the circumferential direction. Moreover, other structures are the same as those of the first embodiment.

[0038] The respective convex portions 23 and concave portions 24 of the segmented core 212 are assembled to be fitted with adjacent segmented cores 212, and are welded and fixed in the groove 22 on the outer peripheral side of the abutting portion. In addition, in the stator core 11 in the second embodiment, the outer peripheral portions of the abutting portions formed between the mutually adjacent segmented cores 212 are joined without gaps by welding.

[0039] On the other hand, a minute gap 21 is formed on the inner peripheral side of the abutting portion between the segmented cores 212. In the stator core 11 in the second embodiment, within the range of manufacturing deviations, the gap 21 is formed at most positions of the respective abutting portions between the segmented cores 212, and the width and size of the gap of the gap 21 are different for the abutting portions between the respective segmented cores 212. Especially in the case of the structure in which the outer peripheral portion is joined by welding, the intrusion depth of the welded joint region in the radial direction has a relatively large deviation during manufacturing. Therefore, as described above, the deviation of the radial width of the minute gap 21 remaining on the inner peripheral side is large.

[0040] In this way, by adopting the segmented core 212, the yield rate of the electromagnetic steel sheet is improved, and thus the material cost can be reduced. Furthermore, by adopting the segmented core 212 with a small number of segments, the number of components can be reduced and the manufacturability can be improved. Moreover, since the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (condition A) or 2P < N < 4P (condition B), the shaft voltage generated by the combination of the number of poles and the number of segments of the stator core 11 can be reduced. Torque ripple generated by the number of poles and the number of segments of the stator core 11 can also be suppressed.

[0041] By assembling the divided cores 212 with each other using the convex portion 23 and the concave portion 24 of the abutting portion, the positioning accuracy of the divided cores 212 can be improved, and the manufacturability can be enhanced. In addition, by welding the outer peripheral side of the abutting portion between the divided cores 212, the rigidity of the stator core 11 can be increased. In addition, by using the groove 22 as a welding groove to join between the divided cores 212, the welding bead does not protrude from the outer periphery of the stator core 11, and the unevenness on the outer periphery of the stator core 11 can be eliminated. Moreover, when press-fitted into the housing, the assembly of the stator 10 becomes easy. In addition, by the (core back division) structure divided from the circumferential center portion of the winding groove 15 to the core back 13, the strain of the teeth 14 can be suppressed, the manufacturing strain of the entire buried magnet type motor can be reduced, and the motor loss can be decreased.

[0042] In addition, the circumferential division number N of the stator core 11 is a factor of the number S of the winding grooves 15, and the shapes of the divided cores 12 constituting the stator core 11 can be made all the same. Therefore, the manufacturing cost of the divided cores 212 can be reduced.

[0043] On the other hand, as shown in the second embodiment, since the groove 22 exists in the outer peripheral portion of the abutting portion of the divided core 212, it becomes the main cause of the permeability harmonic and an axial voltage is generated. Moreover, by generating a shape deviation in the groove 22, it can be considered that the axial voltage becomes larger. However, by applying the division number that satisfies P < N < 2P (condition A) or 2P < N < 4P (condition B) described in the first embodiment, the axial voltage can be more effectively reduced.

[0044] In addition, although not shown, even when the combination of the number of pole pairs and the number of slots is different, if the relationship between the number of pole pairs and the division number satisfies P < N < 2P (condition A) or 2P < N < 4P (condition B), the same effect can be achieved.

[0045] In addition, although not shown, even for different rotor structures, if the above relationship between the number of pole pairs and the division number satisfies P < N < 2P (condition A) or 2P < N < 4P (condition B), the same effect can be achieved.

[0046] In addition, when the gaps 21 formed in the abutting portions between the mutually adjacent divided cores 212, which are described as the structure of the stator core 11 in the second embodiment, are formed with different widths and sizes from each other, by setting the division number to be a small division number that satisfies P < N < 2P (condition A), the permeability harmonic generated due to the deviation of the gaps 21 can be reduced, and the axial voltage can be more effectively reduced.

[0047] In addition, in Embodiment 2, as a preferred example of the fixing structure between adjacent segmented cores 212, a structure strengthened and fixed by welding was described. However, as the fixing structure between adjacent segmented cores 212, a stator core 11 that is circularly joined only by a structure in which the convex portions 23 and concave portions 24 of the respective segmented cores 212 are engaged can also adopt a structure in which a circular frame is externally inserted on its outer periphery. In this case, the joining based on welding can be omitted. In addition, a structure in which an adhesive such as resin is disposed between adjacent segmented cores 212 and they are adhesively fixed to each other can also be adopted.

[0048] Even when these fixing structures are adopted, especially when a gap 21 is formed in the abutting portion between adjacent segmented cores 212, and further, even when their respective widths and sizes are different from each other, as long as the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the effects described in Embodiment 1 can be obtained.

[0049] As described above, the rotating electric machine of Embodiment 2 is formed by providing convex portions and concave portions for insertion in the abutting portion of the segmented core and providing grooves in the outer peripheral portion, and the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B). Therefore, the rotating electric machine of Embodiment 2 can reduce material costs, improve manufacturability, reduce shaft voltage, and suppress torque ripple at the same time.

[0050] Embodiment 3. Embodiment 3 is formed by axially dividing the stator core into four parts and performing rotational lamination by rotating 30 degrees.

[0051] Regarding the rotating electric machine of Embodiment 3, based on the Figure 17 which is a perspective view of a 30-degree rotating four-pole rotational lamination stator core, the description will be centered on the differences from Embodiment 1. In Embodiment 3 Figure 17 the same reference numerals are added to the parts that are the same as or equivalent to those in Embodiment 1. In addition, in order to distinguish it from Embodiment 1, it is designated as the rotating electric machine 300.

[0052] The stator core 11 of the rotating electric machine 300 of Embodiment 3 is divided into four sections in the axial direction. In Figure 17 section A is denoted as SGA, section B is denoted as SGB, section C is denoted as SGC, and section D is denoted as SGD. It is configured such that with the rotation axis of the rotor 30 as the axis, the section B rotates by a mechanical angle of 30 degrees relative to the section A, the section C rotates by a mechanical angle of 30 degrees relative to the section B, and the section D rotates by a mechanical angle of 30 degrees relative to the section C, and the sections A to D are stacked axially. In addition, each section of the stator core 11 is composed of a segmented core 12 with a segmentation number of 6. Other structures are the same as those of the rotating electrical machine in the first embodiment.

[0053] By adopting such a structure, in addition to the effects of the rotating electrical machine in the first embodiment, the rigidity of the stator core 11 formed by combining the segmented cores 12 can be improved, and the vibration resistance and strength can be enhanced. In addition, since the circumferential positions of the winding slots 15 are the same in each section, the insertion of the coils 16 becomes easy, and the manufacturability is improved. Furthermore, the influence of the magnetic anisotropy in the rolling direction and the direction perpendicular to it of the teeth 14 of the stator core 11, which will be described later, can be reduced, and the losses, shaft voltage, and torque ripple of the buried magnet type motor can be decreased.

[0054] Let the circumferential segmentation number of the stator core 11 be N (an integer), the axial segmentation number of the stator core 11 be t (an integer of 2 or more), let n be an integer, and k be an integer satisfying k = t / n for generalization. If it is configured such that the sections of the stator core 11 axially segmented into t sections rotate by a mechanical angle of 360 / N / k degrees with the rotation axis of the rotor 30 as the axis relative to the axially adjacent sections and are stacked axially, it has the same effects as those of the third embodiment.

[0055] In addition, generalization is performed using the number S of the winding slots 15 of the stator core 11. If it is configured such that the sections of the stator core 11 axially segmented into t sections rotate by a mechanical angle of (360 / S)×n degrees with the rotation axis of the rotor 30 as the axis relative to the axially adjacent sections and are stacked axially, it has the same effects as those of the third embodiment.

[0056] In addition, as in the second embodiment, by arranging concave and convex portions at the abutting portions to assemble the segmented cores 12 with each other, the positioning accuracy of the segmented cores 12 can be improved, and the manufacturability can be enhanced. In addition, by welding the outer peripheral portions of the abutting portions of the segmented cores 12, the rigidity of the stator core 11 can be further improved. Furthermore, by performing welding in the slots of the outer peripheral portion of the segmented core 12, the unevenness on the outer periphery of the stator core 11 is eliminated, and when inserting the stator core 11 into a housing or the like, the assembly of the stator 10 becomes easy.

[0057] As described above, the rotating electrical machine of the third embodiment axially segments the stator core into four parts and rotates and stacks them by 30 degrees. Therefore, the rotating electric machine according to Embodiment 3 can reduce the material cost, improve the manufacturability, simultaneously reduce the shaft voltage, and suppress the torque ripple. Furthermore, it is possible to increase the rigidity of the stator core 11, improve the vibration resistance and strength, and reduce the influence of the magnetic anisotropy in the rolling direction and the direction perpendicular thereto of the teeth 14 of the stator core 11.

[0058] Embodiment 4. Embodiment 4 is configured such that the magnetic anisotropy of the teeth of the stator core is balanced over the entire buried magnet type motor.

[0059] Regarding the rotating electric machine according to Embodiment 4, based on the explanatory diagram of the rolling direction and the tooth direction in the sectional view of the segmented core, Figure 18 the explanatory diagram of the tooth numbers in the sectional view of the segmented core, Figure 19 the explanatory diagram of the tooth direction component of the rolling direction magnetic characteristics of the teeth at the same circumferential position in each section of the stator core in the comparative example, Figure 20 the perspective view of the stator core, Figure 21 and the explanatory diagram of the tooth direction component of the rolling direction magnetic characteristics of the teeth at the same circumferential position in each section of the stator core, Figure 22 the description will be centered on the differences from Embodiment 1. In Embodiment 4, Figure 18 , Figure 19 , Figure 21 parts that are the same as or equivalent to those in Embodiment 1 are assigned the same reference numerals. In addition, in order to distinguish it from the rotating electric machine 100 of Embodiment 1, it is designated as the rotating electric machine 400.

[0060] In Figure 18 , the rolling direction is denoted as "RD", and the tooth direction is denoted as "TD". In addition, the angle formed by the rolling direction vector and the tooth direction vector is set as θ. In the electromagnetic steel sheets constituting the segmented core 12, the magnetic characteristics may be different in the rolling direction and the direction perpendicular thereto. As Figure 18 shown, in all the teeth 14, the rolling direction does not coincide with the tooth direction, which is the direction in which the teeth 14 face the rotation center. To make the following description easier to understand, tooth numbers are described in Figure 19 . The teeth of the segmented core 12 are numbered in the counterclockwise direction along the circumference. The teeth from tooth number 1 to tooth number 8 are denoted as TN1, TN2, TN3, TN4, TN5, TN6, TN7, and TN8.

[0061] When the angle formed by the rolling direction vector and the tooth direction vector is set as θ, the tooth direction component of the rolling direction magnetic characteristic of each tooth 14 is obtained from the cosine of the rolling direction vector. And when combining the segments of the stator core 11 with 4 axial levels, the sum of the tooth direction components of the rolling direction magnetic characteristics of the teeth 14 at the same circumferential position is taken.

[0062] First, as a comparative example, in Figure 20 it is described that the stator core 11 of the rotating electric machine 300 of Embodiment 3 is divided into 4 levels and the respective segments are rotationally laminated by 30 degrees. Figure 17 Figure 20 are the results of calculating the tooth direction components of the rolling direction magnetic characteristics of the respective teeth with tooth numbers 1 to 8 of the stator core 11 at the same circumferential position in each segment. If the sum of the tooth direction components of the rolling direction magnetic characteristics of the teeth 14 at the same circumferential position is taken, there are two values of 3.79 and 3.86. Therefore, it can be understood that in the stator core 11 described in Figure 17 the magnetic characteristics of the tooth direction components are different. Therefore, due to the influence of magnetic anisotropy in the rolling direction and the perpendicular direction in the teeth 14 of the stator core 11, an increase in the loss of the buried magnet type motor, the generation of shaft voltage, and an increase in torque ripple may occur.

[0063] Therefore, as Figure 21 shown, the stator core 11 of the rotating electric machine 400 of Embodiment 4 is divided into 4 segments in the axial direction, and each segment is rotated by a mechanical angle of 15 degrees. That is, it is configured such that with the rotation axis of the rotor 30 as the axis, segment B rotates by a mechanical angle of 15 degrees with respect to segment A, segment C rotates by a mechanical angle of 15 degrees with respect to segment B, and segment D rotates by a mechanical angle of 15 degrees with respect to segment C, and segments A to D are stacked in the axial direction. In addition, each segment of the stator core 11 is composed of a split core 12 with a split number of 6. Other structural elements are the same as those in Embodiment 1.

[0064] Figure 22 Figure 21 are the results of calculating the tooth direction components of the rolling direction magnetic characteristics of the teeth with tooth numbers 1 to 8 of the stator core 11 of the rotating electric machine 400 of Embodiment 4 shown in

[0065] When combining the respective segments of the 4-level stator core 11, the sum of the tooth direction components is all 3.82, and thus it can be understood that it is balanced. Furthermore, it is possible to improve the rigidity of the stator core 11 combined with the segmented core 12, and improve the vibration resistance and strength. In addition, since the circumferential position of the winding slot 15 is the same in each section, the insertion of the coil 16 becomes easy, improving the manufacturability.

[0066] Here, the circumferential segmentation number of the stator core 11 is set to N, the axial segmentation number of the stator core 11 is set to t, n is set as an integer, and t is set to a number satisfying t = 4n for generalization. If each section of the stator core 11 axially segmented into t sections is rotated by a mechanical angle of 360 / N / 4 degrees about the rotation axis of the rotor 30 with respect to the axially adjacent section and stacked in t stages axially, the same effect is obtained.

[0067] In addition, as described in Embodiment 2, by arranging concave and convex portions at the abutting portions to assemble the segmented cores 12 with each other, it is possible to improve the positioning accuracy of the segmented cores 12 and improve the manufacturability. In addition, by welding the outer peripheral portion of the abutting portion, the rigidity of the stator core 11 can be further improved. Furthermore, by performing welding in the groove on the outer peripheral side of the abutting portion of the segmented core 12, the unevenness on the outer periphery of the stator core 11 is eliminated, and when the stator core 11 is inserted into a housing or the like, the assembly of the stator 10 becomes easy.

[0068] As described above, the rotating electric machine of Embodiment 4 balances the magnetic anisotropy of the teeth of the stator core over the entire buried magnet type motor. Therefore, the rotating electric machine of Embodiment 4 can reduce the material cost, improve the manufacturability, reduce the shaft voltage, and suppress the torque ripple at the same time. Furthermore, it is possible to balance the influence of the magnetic anisotropy in the rolling direction and the right-angle direction of the teeth 14 of the stator core 11, improve the rigidity of the stator core 11, and improve the vibration resistance and strength.

[0069] Embodiment 5. Embodiment 5 has a structure in which the segmented core is segmented at the center of the tooth, i.e., tooth segmentation.

[0070] Regarding the rotating electric machine of Embodiment 5, based on Figure 23 which is a cross-sectional view of the segmented core that constitutes the stator core, Figure 24 which is a cross-sectional view of a 6-segment 8-pole 48-slot double V-shaped buried magnet type motor obtained by segmenting the stator core at the center of the tooth, Figure 25 which is a perspective view of a 30-degree rotated 6-pole rotating laminated stator core, Figure 26 and a cross-sectional view of a 12-segment 8-pole 48-slot double V-shaped buried magnet type motor segmented at the center of the tooth in a modified example, In Embodiment 5, Figures 23 - 26In the following, the same reference numerals are given to the parts that are the same as or equivalent to those in Embodiment 1. In addition, in order to distinguish from the rotating electric machine 100 and the segmented core 12 of Embodiment 1, they are designated as a rotating electric machine 500 and a segmented core 512.

[0071] As Figure 23 shown, the segmented core 512 of the stator core 11 constituting the rotating electric machine 500 of Embodiment 5 is formed by laminating a plurality of electromagnetic steel sheets, and is composed of a plurality of teeth 14 protruding from the core back 13 on the arc toward the central axis in the inner circumferential direction, and a winding slot 15 which is a region between adjacent teeth 14. Moreover, the segmented core 512 is segmented (tooth segmentation) from the circumferential center portion of the tooth 14 to the core back 13. Eight teeth 14 are arranged in the circumferential direction in each segmented core 512, and the arc angle of the segmented core 512 is 60 degrees.

[0072] As Figure 24 shown, in the rotating electric machine 500 of Embodiment 5, the stator core 11 is constituted by the segmented core 512 described in Figure 23 , and the other structures are the same as those in Embodiment 1.

[0073] As Figure 25 shown, the stator core 11 is axially segmented into six segments (SGA, SGB, SGC, SGD, SGE, SGF). Each segment of the stator core 11 rotates by a mechanical angle of 30 degrees about the rotation axis of the rotor 30 with respect to the axially adjacent segment, and is stacked axially. In the figure, segment E is denoted as SGE, and segment F is denoted as SGF.

[0074] By configuring in this way, with the segmented core 512, the yield rate of the electromagnetic steel sheets is improved, and thus the material cost can be reduced. Furthermore, by adopting the segmented core 512 with a small number of segments, the number of components can be reduced, and the manufacturability can be improved. In addition, the shaft voltage generated by the combination of the number of poles and the number of segments of the stator core 11 can be reduced. The torque ripple generated by the number of poles and the number of segments of the stator core 11 can also be suppressed.

[0075] In addition, in the tooth segmentation, since the segmentation position is outside the winding slot 15, strain is not easily generated in the winding slot 15, insertion of the coil 16 becomes easy, and the manufacturability can be improved.

[0076] In addition, the circumferential segmentation number N of the stator core 11 is a factor of the number S of winding slots 15, and the shapes of the segmented cores 12 constituting the stator core 11 can all be the same, so that the manufacturing cost of the segmented core 512 can be reduced.

[0077] In addition, Figure 26It is an 8-pole 48-slot distributed winding motor using a 12-segment core. However, when the number of pole pairs is set to P and the number of equal divisions in the circumferential direction of the stator core 11 is set to N, if it is a rotating electrical machine that satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effect as in Embodiment 5 is achieved. In addition, in Figure 26 it is designated as the rotating electrical machine 501 in order to distinguish it from the Figure 24 , Figure 25 rotating electrical machine 500.

[0078] In addition, even when the combination of the number of pole pairs and the number of slots is different, if the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effect can be achieved. In addition, even for different rotor structures, if the above relationship between the number of pole pairs and the number of segments satisfies (P < N < 2P (Condition A) or 2P < N < 4P (Condition B)), the same effect can be achieved.

[0079] In addition, as in Embodiment 2, by arranging the concavo-convex portions at the abutting portions to assemble the segment cores 512 with each other, the positioning accuracy of the segment core 12 can be improved and the manufacturability can be improved. In addition, by welding the outer peripheral portion of the abutting portion of the segment core 512, the rigidity of the stator core 11 can be further improved. Furthermore, by performing welding in the slots in the outer peripheral portion of the segment core 512, the unevenness on the outer periphery of the stator core 11 is eliminated, and when the stator core 11 is inserted into a housing or the like, the assembly of the stator 10 becomes easy. At this time, since there are slots in the outer peripheral portion of the abutting portion of the segment core 512, it becomes the main cause of magnetic permeability harmonics and shaft voltage is generated. Moreover, considering the shape deviation generated in the slots, the shaft voltage becomes larger. However, by applying the number of segments that satisfies the relationship of P < N < 2P (Condition A) or 2P < N < 4P (Condition B) between the number of pole pairs and the number of segments, the shaft voltage can be more effectively reduced.

[0080] In addition, when the gaps 21 formed at the abutting portions between the mutually adjacent segment cores 512, which were described as the structure of the stator core 11 in Embodiment 5, are formed with different widths and sizes respectively, by setting the number of segments to be small and satisfying P < N < 2P (Condition A), the magnetic permeability harmonics generated due to the deviation of the gaps 21 can be reduced, and the shaft voltage can be more effectively reduced.

[0081] Moreover, by setting a structure in which the stator core 11 is stacked by rotating the split core 512 at a mechanical angle of 30 degrees, the rigidity of the stator core 11 combined with the split core 512 can be improved, and the vibration resistance and strength can be improved. In addition, since the circumferential position of the winding slot 15 is the same in each section, the insertion of the coil 16 becomes easy, and the manufacturability is improved. Furthermore, the influence of the magnetic anisotropy of the teeth 14 of the stator core 11 in the rolling direction and the right angle direction can be reduced, and the loss, torque pulsation, and shaft voltage of the embedded magnet type motor can be reduced.

[0082] In addition, when the number of circumferential divisions of the stator core 11 is set to N, the number of axial divisions of the stator core 11 is set to t, n is set to an integer, and k is set to a number satisfying k=t / n, if the segments of the stator core 11 divided into t pieces in the axial direction are rotated by a mechanical angle of 360 / N / k degrees relative to the axially adjacent segments and t levels are stacked axially, the same effect as implementation mode 3 is achieved.

[0083] In addition, when t is a number satisfying t=4n, if the segments of the stator core 11 divided into t pieces in the axial direction are rotated by a mechanical angle of 360 / N / 4 degrees relative to the axially adjacent segments and stacked in t stages in the axial direction, the same effect as implementation mode 4 is achieved.

[0084] As described above, the rotating electrical machine according to the fifth embodiment is configured such that the split core body is split at the center portion of the tooth and the teeth are split. Therefore, the rotating electrical machine of Embodiment 5 can reduce material cost, improve manufacturability, reduce shaft voltage, and suppress torque pulsation. Furthermore, winding slots 15 are less likely to be strained, coils 16 can be easily inserted, and manufacturability can be improved.

[0085] Implementation method 6. Embodiment 6 is an embodiment in which one of the contact portions of the split core is formed as the core back portion and the other is formed as the tooth portion.

[0086] In the rotating electrical machine of the sixth embodiment, based on the cross-sectional view of the split core body Figure 27 , as a cross-sectional view of a 4-segment 6-pole 54-slot double V-shaped embedded magnet type motor divided by core back division and tooth division Figure 28 , and a three-dimensional view of a 45-degree-rotated 2-stage rotating laminated stator core Figure 29 , the description will focus on the differences from Implementation 1. In implementation mode 6 Figures 27 - 29 In the embodiment, the same or corresponding parts as those in Implementation 1 are given the same reference numerals. In order to distinguish from the rotating electrical machine 100 and the split core body 12 of the first embodiment, they are referred to as the rotating electrical machine 600 and the split core body 612 .

[0087] As shown Figure 27 in FIG. 3, the segmented core 612 of the stator core 11 that constitutes the rotating electric machine 600 of Embodiment 6 is formed by laminating a plurality of electromagnetic steel sheets, and includes a plurality of teeth 14 that project from the core back 13 on the arc toward the central axis in the inner circumferential direction, and a winding slot 15 that is a region between adjacent teeth 14. Further, the segmented core 612 has one abutting portion segmented at the core back, and the other abutting portion segmented by the teeth. 13.5 teeth are equally arranged in the circumferential direction, and the arc angle of the segmented core 612 is 90 degrees.

[0088] As shown Figure 28 in FIG. 4, in the rotating electric machine 600 of Embodiment 6, the stator core 11 is constituted by the segmented core 612 described in Figure 27 the above, and the other structures are the same as those of Embodiment 1.

[0089] As shown Figure 29 in FIG. 5, the stator core 11 is divided into two segments in the axial direction, and each segment of the stator core 11 is rotated by a mechanical angle of 45 degrees with respect to the adjacent segment in the axial direction, and is stacked in two stages in the axial direction to be constituted. In this way, a 6-pole 54-slot buried magnet type distributed winding motor using a 4-segmented core is constituted.

[0090] By configuring in this way, the yield rate of the electromagnetic steel sheets of the segmented core 612 is improved, and thus the material cost can be reduced. Further, by adopting the segmented core 612 with a small number of segments, the number of components can be reduced and the manufacturability can be improved. In addition, the shaft voltage generated by the combination of the number of poles and the number of segments of the stator core 11 can be reduced. Torque ripple generated by the number of poles and the number of segments of the stator core 11 can also be suppressed.

[0091] In addition, although not shown, even in a 6-pole 54-slot buried magnet type distributed winding motor, as long as the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B) in the rotating electric machine, the same effects as those of Embodiment 6 can be achieved. At this time, even if only one of the core back segmentation and the tooth segmentation is performed, the same effects can be obtained.

[0092] Further, even when the combination of the number of pole pairs and the number of slots is different, as long as the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effects can be achieved. Further, even for different rotor structures, as long as the relationship between the number of pole pairs and the number of segments satisfies P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the same effects can be achieved.

[0093] In addition, as in Embodiment 2, by arranging concavo-convex portions at the abutting portions to assemble the divided cores 612 to each other, the positioning accuracy of the divided cores 12 can be improved, and the manufacturability can be enhanced. Further, by welding the outer peripheral portions of the abutting portions of the divided cores 612, the rigidity of the stator core 11 can be further increased. Moreover, by performing welding in the grooves in the outer peripheral portions of the divided cores 612, the unevenness on the outer periphery of the stator core 11 is eliminated, and when the stator core 11 is inserted into a housing or the like, the assembly of the stator 10 becomes easy. At this time, since there are grooves in the outer peripheral portions of the abutting portions of the divided cores 612, they become the main cause of magnetic permeability harmonics and shaft voltage is generated. Also, considering that shape deviations occur in the grooves, the shaft voltage increases. However, by applying a division number that satisfies the relationship of the number of pole pairs and the division number: P < N < 2P (Condition A) or 2P < N < 4P (Condition B), the shaft voltage can be more effectively reduced.

[0094] Moreover, by adopting a structure in which layers are stacked by rotating by 45 degrees in mechanical angle, the rigidity of the stator core 11 incorporating the divided cores 612 can be increased, and the vibration resistance and strength can be improved. In addition, since the circumferential positions of the winding slots 15 are the same in each section, the insertion of the coils 16 becomes easy and the manufacturability is enhanced. Furthermore, the influence of the magnetic anisotropy in the rolling direction and the direction perpendicular to the rolling direction of the teeth 14 of the stator core 11 can be reduced, and the losses, torque ripple, and shaft voltage of the buried magnet type motor can be decreased.

[0095] In addition, when the gaps 21 formed at the abutting portions between the mutually adjacent divided cores 612, which were described as the structure of the stator core 11 in Embodiment 6, are formed with different widths and sizes respectively, by setting the division number to be a small division number that satisfies P < N < 2P (Condition A), the magnetic permeability harmonics generated due to the deviation of the gaps 21 can be reduced, and the shaft voltage can be more effectively decreased.

[0096] In addition, when the circumferential division number of the stator core 11 is set to N, the axial division number of the stator core 11 is set to t, n is an integer, and k is a number that satisfies k = t / n, if the structure is such that the sections of the stator core 11 axially divided into t sections are rotated by a mechanical angle of 360 / N / k degrees about the rotation axis of the rotor 30 with respect to the axially adjacent sections and stacked axially in t stages, the same effects as in Embodiment 3 are achieved.

[0097] In addition, when t is a number that satisfies t = 4n, if the structure is such that the sections of the stator core 11 axially divided into t sections are rotated by a mechanical angle of 360 / N / 4 degrees about the rotation axis of the rotor 30 with respect to the axially adjacent sections and stacked axially in t stages, the same effects as in Embodiment 4 are achieved.

[0098] As described above, the rotating electric machine according to the sixth embodiment is a rotating electric machine in which one of the abutting portions of the divided core is set as the core back division and the other is set as the tooth division. Therefore, the rotating electric machine according to the sixth embodiment can reduce material costs, improve manufacturability, reduce shaft voltage, and suppress torque ripple at the same time.

[0099] This application describes various exemplified embodiments and examples, but the various features, forms, and functions described in one or more embodiments are not limited to the application of a specific embodiment, and can be applied to the embodiments alone or in various combinations. Therefore, countless unexemplified variations can be envisioned within the scope of the technology disclosed in this application. For example, assume cases including deforming, adding, or omitting at least one component, and cases of extracting at least one component and combining it with the components of other embodiments. Industrial Applicability

[0100] The rotating electric machine of this application can obtain a rotating electric machine that can reduce material costs, improve manufacturability, reduce shaft voltage, and suppress torque ripple at the same time, and thus can be widely applied to rotating electric machines. Reference Numeral Explanation

[0101] 10 Stator 11 Stator Core 12, 212, 512, 612 Divided Core 13 Core Back 14 Tooth 15 Winding Slot 16 Coil 21 Air Gap 22 Slot 23 Protrusion 24 Recess 30 Rotor 31 Rotor Core 32 Shaft 33 Permanent Magnet 34 Magnet Slot 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 200, 300, 400, 500, 501, 600 Rotating Electric Machine.

Claims

1. A rotating electric machine, comprising: a stator having a stator core formed by combining a plurality of segmented cores segmented in the circumferential direction into an annular shape, and coils wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located on the central axis of the stator, and magnetic poles with a pole pair number of P arranged on the rotor core, wherein the rotating electric machine is characterized in that the segmented core has an arcuate core back and a plurality of teeth protruding from the core back toward the inner circumferential direction, with winding slots between the teeth, the number of the teeth being equal, and when the number of segments of the segmented core is set to N, P < N < 2P is satisfied.

2. A rotating electric machine, comprising: a stator having a stator core formed by combining a plurality of segmented cores segmented in the circumferential direction into an annular shape, and coils wound around the stator core in a distributed winding manner; and a rotor capable of rotating relative to the stator, having a rotor core fixed to a shaft located on the central axis of the stator, and magnetic poles with a pole pair number of P arranged on the rotor core, wherein the rotating electric machine is characterized in that the segmented core has an arcuate core back and a plurality of teeth protruding from the core back toward the inner circumferential direction, with winding slots between the teeth, the number of the teeth being equal, and when the number of segments of the segmented core is set to N, 2P < N < 4P is satisfied.

3. The rotating electric machine according to claim 1 or 2, characterized in that there is a gap in the abutting portion formed between the mutually adjacent segmented cores.

4. The rotating electric machine according to claim 3, characterized in that the width or size of the gap varies according to each abutting portion of the segmented core.

5. The rotating electric machine according to any one of claims 1 to 4, characterized in that the stator core is joined to each other by welding at the outer peripheral portion of the abutting portion of the plurality of segmented cores constituting the stator core.

6. The rotating electric machine according to any one of claims 1 to 4, characterized in that the stator core has grooves respectively at the outer peripheral portions of the abutting portions of the plurality of segmented cores constituting the stator core.

7. The rotating electric machine according to claim 6, characterized in that the groove is used as a welding groove.

8. The rotating electric machine according to any one of claims 1 to 7, characterized in that one circumferential abutting portion of the segmented core has a convex portion, and the other circumferential abutting portion has a concave portion, and the stator core has a structure in which the concave portions and the convex portions of the respective abutting portions of the segmented core are engaged with each other.

9. The rotating electric machine according to any one of claims 1 to 8, characterized in that when the number of winding slots of the stator core is set to an integer S, the circumferential segmentation number N of the stator core is a factor of S.

10. The rotating electric machine according to any one of claims 1 to 9, characterized in that the stator core is composed of the segmented cores segmented from the circumferential central portion of the winding slot to the core back.

11. The rotating electric machine according to any one of claims 1 to 9, characterized in that The stator core is composed of the segmented cores that are segmented from the circumferential central part of the teeth to the back of the core.

12. The rotating electrical machine according to any one of claims 1 to 9, characterized in that the stator core is composed of the segmented cores, one of the segmented cores is segmented from the circumferential central part of the winding slot to the back of the core, and the other is segmented from the circumferential central part of the teeth to the back of the core.

13. The rotating electrical machine according to any one of claims 1 to 12, characterized in that when the number of winding slots of the stator core is set as an integer S, t is an integer of 2 or more, and under the condition that n is an integer, the stator core is formed by stacking t segments in the rotating shaft direction, each of the segments is composed of a plurality of the segmented cores segmented along the circumferential direction, the adjacent segments in the rotating shaft direction are structures obtained by rotating a mechanical angle of (360 / S)×n degrees around the rotating shaft of the rotor and stacking them axially.

14. The rotating electrical machine according to any one of claims 1 to 12, characterized in that when t is an integer of 2 or more, n is an integer, and k satisfies the condition of k = t / n, the stator core is formed by stacking t segments in the rotating shaft direction, each of the segments is composed of a plurality of the segmented cores segmented along the circumferential direction, the adjacent segments in the rotating shaft direction are structures obtained by rotating a mechanical angle of 360 / N / k degrees around the rotating shaft of the rotor and stacking them axially.

15. The rotating electrical machine according to any one of claims 1 to 12, characterized in that when t is an integer of 2 or more, n is an integer, and the condition of t = 4n is satisfied, the stator core is formed by stacking t segments in the rotating shaft direction, each of the segments is composed of a plurality of the segmented cores segmented along the circumferential direction, the adjacent segments in the rotating shaft direction are structures obtained by rotating a mechanical angle of 360 / N / 4 degrees around the rotating shaft of the rotor and stacking them axially.

16. The rotating electrical machine according to any one of claims 1 to 15, characterized in that the rotor core is of the embedded magnet type having a plurality of magnet slots for inserting and fixing magnets and a plurality of permanent magnets for forming magnetic poles.

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