Rotating electric machine and manufacturing method thereof

Abstract

To provide a rotary electric machine capable of reducing pulsation of cogging torque and a method for manufacturing a rotary electric machine.SOLUTION: A rotary electric machine 10 includes a stator 11 having a stator core 21 and a coil 22, and a rotor 12 having a plurality of permanent magnets M arranged in a circumferential direction of a rotor core 26. The number S of slots 25 that the stator core 21 has is a multiple of 6 that is 12 or more. For q=S / (the number of poles of the rotor×the number of phases of the coil), q is a fraction and satisfies q<1 / 2. For the plurality of permanent magnets M, the minimum prime factor of S / 6 is represented by z, and the permanent magnets M arranged every (360 / S)×3×Z[°] are set as permanent magnets M belonging to the same group. In at least one group, the surface magnetic fluxes of permanent magnets M belonging to the same group are different. Further, the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same for each group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine and a method for manufacturing a rotating electric machine. [Background technology]

[0002] The rotating electric machine includes a stator and a rotor. The stator has a stator core and a coil. The stator core has a cylindrical yoke, a plurality of teeth, and a plurality of slots. Each tooth extends from the yoke in a radial direction of the yoke. The plurality of teeth are arranged at intervals in the circumferential direction of the yoke. The slot is a space located between adjacent teeth in the circumferential direction of the yoke. The coil is wound around the teeth in a concentrated winding manner. The rotor has a cylindrical rotor core and a plurality of permanent magnets arranged in the circumferential direction of the rotor core. The permanent magnets are S-pole magnets or N-pole magnets whose magnetization direction is different from that of the S-pole magnets. The S-pole magnets and N-pole magnets are arranged alternately in the circumferential direction of the rotor core.

[0003] In general, when q = number of slots / (number of rotor poles × number of coil phases), a rotating electric machine where q is a fraction and q<1 / 2 is called a fractional slot rotating electric machine. For example, the motor in Patent Document 1 has a three-phase, 12-slot stator and a 14-pole rotor. This motor is a fractional slot motor where q = 12 / (14×3) = 2 / 7. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-098791 Summary of the Invention [Problem to be solved by the invention]

[0005] In a rotating electric machine with fractional slots, if there is variation in the surface magnetic flux of the permanent magnets, the torque value changes for each electrical angle during one mechanical angle cycle, causing pulsation in the cogging torque. [Means for solving the problem]

[0006] A rotating electric machine for solving the above problems includes a stator having a cylindrical yoke, a plurality of teeth extending from the yoke in a radial direction of the yoke and arranged at intervals in a circumferential direction of the yoke, and a stator core having slots which are spaces located between adjacent teeth in the circumferential direction of the yoke, and a coil wound in a concentrated winding manner around the teeth; a cylindrical rotor core, and a rotor having a plurality of permanent magnets arranged in the circumferential direction of the rotor core, the permanent magnets being S-pole magnets or N-pole magnets whose magnetization direction is different from that of the S-pole magnets, and the S-pole magnets and the N-pole magnets are arranged in a circumferential direction of the rotor core. The rotating electric machine has slots arranged alternately in the circumferential direction of the rotor core, the number S of the slots being a multiple of 6 that is equal to or greater than 12, and when q = S / (number of poles of the rotor × number of phases of the coil), q is a fraction such that q < 1 / 2, and when the smallest prime factor of S / 6 is Z and the multiple permanent magnets are arranged every (360 / S) × 3 × Z [°] and are considered to belong to the same group, the surface magnetic flux of the permanent magnets belonging to the same group is different in at least one group, and the total value of the surface magnetic flux of the permanent magnets belonging to the same group is the same in each group.

[0007] The total surface magnetic flux of permanent magnets belonging to the same group is the same for each group. As a result, even if the surface magnetic flux of the permanent magnets varies, the interlinkage magnetic flux is the same for each electrical angle cycle, so the difference in interlinkage magnetic flux for each electrical angle cycle is small. This reduces the pulsation of the cogging torque.

[0008] In the above rotating electric machine, each of the plurality of permanent magnets may be formed of two magnet components arranged in a circumferential direction of the rotor core. A method for manufacturing a rotating electric machine for solving the above problems includes a stator having a cylindrical yoke, a stator core having a plurality of teeth extending from the yoke in a radial direction of the yoke and arranged at intervals in the circumferential direction of the yoke, and slots which are spaces located between adjacent teeth in the circumferential direction of the yoke, and a coil wound in concentrated winding around the teeth, a cylindrical rotor core, and a rotor having a plurality of permanent magnets arranged in the circumferential direction of the rotor core, the permanent magnets being S-pole magnets or N-pole magnets whose magnetization direction is different from that of the S-pole magnets, the S-pole magnets and the N-pole magnets being arranged alternately in the circumferential direction of the rotor core, the number S of the slots is a multiple of 6 that is equal to or greater than 12, and q=S / (number of poles of the rotor×front A manufacturing method for a rotating electric machine in which q is a fraction and q<1 / 2, where q is the number of phases of the coils, the manufacturing method includes an acquisition step of acquiring a surface magnetic flux or magnetic flux density for each of the plurality of permanent magnets, and an arrangement step of arranging the plurality of permanent magnets based on the surface magnetic flux or magnetic flux density of the permanent magnet acquired in the acquisition step, wherein, in the arrangement step, the plurality of permanent magnets are arranged every (360 / S)×3×Z [°], where Z is the smallest prime factor of S / 6, and the permanent magnets belong to the same group, such that in at least one group, the surface magnetic flux of the permanent magnets belonging to the same group is different and the total value of the surface magnetic flux of the permanent magnets belonging to the same group is the same in each group.

[0009] In the arrangement process, the permanent magnets are arranged so that the total value of the surface magnetic flux of the permanent magnets belonging to the same group is the same for each group. As a result, even if the surface magnetic flux of the permanent magnets varies, the interlinkage magnetic flux is the same for each electrical angle period, so the difference in interlinkage magnetic flux for each electrical angle period is small. This makes it possible to reduce the pulsation of the cogging torque. Effect of the Invention

[0010] According to the present invention, the pulsation of the cogging torque can be reduced. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Diagram 2] 13 is a graph showing the change in torque over time in Comparative Example 1. [Diagram 3] 13 is a graph showing the change in torque over time in Comparative Example 2. [Figure 4] 4 is a graph showing a change in torque over time in the first embodiment. [Diagram 5] FIG. 11 is a cross-sectional view of a rotating electric machine according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [First embodiment] A first embodiment embodying a rotating electric machine and a manufacturing method thereof will be described below with reference to FIG.

[0013] <<Configuration of a rotating electric machine>> 1, the rotating electric machine 10 includes a cylindrical stator 11 and a cylindrical rotor 12. The stator 11 surrounds the rotor 12. Therefore, the rotor 12 is disposed inside the stator 11.

[0014] <Stator configuration> The stator 11 includes a stator core 21 and U-phase, V-phase, and W-phase coils 22.

[0015] The stator core 21 has a cylindrical yoke 23, a plurality of teeth 24, and a plurality of slots 25. The stator core 21 of the present embodiment has 12 teeth 24 as the plurality of teeth 24, and has 12 slots 25 as the plurality of slots 25.

[0016] The yoke 23 is cylindrical. Each tooth 24 extends from an inner peripheral surface of the yoke 23 radially inward of the stator core 21. The teeth 24 are arranged at intervals in the circumferential direction of the yoke 23. Each slot 25 is a space located between adjacent teeth 24 in the circumferential direction of the yoke 23. The teeth 24 and the slots 25 are arranged alternately in the circumferential direction of the yoke 23.

[0017] The coils 22 are wound in a concentrated manner around the teeth 24. A portion of the coils 22 passes through the slots 25. Note that insulation is provided between the stator core 21 and the coils 22, and between the coils 22 of different phases, by insulating members (not shown).

[0018] <Rotor configuration> The rotor 12 has a cylindrical rotor core 26 and a plurality of permanent magnets M. The rotor 12 of the present embodiment has 14 permanent magnets M as the plurality of permanent magnets M.

[0019] The rotor core 26 is cylindrical. The rotating shaft 13 is inserted into the inside of the rotor core 26. The rotating shaft 13 is fixed to the rotor core 26. The rotating shaft 13 rotates integrally with the rotor 12.

[0020] The multiple permanent magnets M are arranged in the circumferential direction of the rotor core 26. The shape of all the permanent magnets M is the same. Each permanent magnet M is an S-pole magnet or an N-pole magnet. The S-pole magnet is a magnet in which the S-pole exists at the outer portion of the permanent magnet M in the radial direction of the rotor core 26 and the N-pole exists at the inner portion of the permanent magnet M in the radial direction of the rotor core 26. The N-pole magnet is a magnet in which the N-pole exists at the outer portion of the permanent magnet M in the radial direction of the rotor core 26 and the S-pole exists at the inner portion of the permanent magnet M in the radial direction of the rotor core 26. In other words, the magnetization direction of the S-pole magnet and the magnetization direction of the N-pole magnet are different from each other. The S-pole magnets and the N-pole magnets are alternately arranged in the circumferential direction of the rotor core 26. In this embodiment, of the 14 permanent magnets M, there are seven S-pole magnets and seven N-pole magnets.

[0021] In this embodiment, the multiple permanent magnets M are arranged on the outer peripheral surface of the rotor core 26. The rotor 12 in this embodiment is an SPM (Surface Permanent Magnet) type rotor in which the permanent magnets M are arranged on the surface of the rotor 12. The surface of each permanent magnet M facing the outer peripheral surface of the rotor core 26 is curved to fit along the outer peripheral surface of the rotor core 26. In addition, the surface of each permanent magnet M opposite to the surface facing the outer peripheral surface of the rotor core 26 is curved to be convex toward the radially outer side of the rotor core 26.

[0022] The number S of the slots 25 is set to S=6a, where a is a natural number equal to or greater than 2. In other words, the number S of the slots 25 is set to a multiple of 6 equal to or greater than 12. In addition, generally, when q=the number S of the slots 25 / (the number of poles of the rotor 12×the number of phases of the coils 22), a rotating electric machine in which q is a fraction and q<1 / 2 is called a fractional slot rotating electric machine. As described above, the stator 11 of this embodiment is a three-phase, 12-slot stator. The rotor 12 of this embodiment is a rotor with 14 poles (7 pole pairs). Therefore, the rotating electric machine 10 of this embodiment is a fractional slot rotating electric machine in which q=12 / (14×3)=2 / 7.

[0023] For multiple permanent magnets M, permanent magnets M arranged at every angle θv [°] are considered to belong to the same group. Here, angle θv [°] is expressed as θv = (360 / S) x 3 x Z [°], where Z is the smallest prime factor of S / 6. Since S / 6 = 6a / 6 = a, P can also be said to be the smallest prime factor of a. The number of permanent magnets M belonging to each group is the same for all groups.

[0024] In this embodiment, the number of slots 25, S=12. Therefore, S / 6=2, Z=2, and θv=(360 / 12)×3×2=180[°]. Therefore, of the 14 permanent magnets M in this embodiment, the permanent magnets M arranged every 180[°] belong to the same group.

[0025] The 14 permanent magnets M are referred to as first to fourteenth magnets M1 to M14. The first to fourteenth magnets M1 to M14 are lined up in the circumferential direction of the rotor core 26 in the clockwise direction in this order. The eighth magnet M8 is disposed at a position shifted by 180° from the first magnet M1. Therefore, the first magnet M1 and the eighth magnet M8 are permanent magnets belonging to the same group. The group to which the first magnet M1 and the eighth magnet M8 belong is defined as the first group. The ninth magnet M9 is disposed at a position shifted by 180° from the second magnet M2. Therefore, the second magnet M2 and the ninth magnet M9 are permanent magnets belonging to the same group. The group to which the second magnet M2 and the ninth magnet M9 belong is defined as the second group. The tenth magnet M10 is disposed at a position shifted by 180° from the third magnet M3. Therefore, the third magnet M3 and the tenth magnet M10 are permanent magnets belonging to the same group. The group to which the third magnet M3 and the tenth magnet M10 belong is defined as the third group. The eleventh magnet M11 is disposed at a position shifted by 180° from the fourth magnet M4. Therefore, the fourth magnet M4 and the eleventh magnet M11 are permanent magnets belonging to the same group. The group to which the fourth magnet M4 and the eleventh magnet M11 belong is called the fourth group. The twelfth magnet M12 is disposed at a position shifted by 180° from the fifth magnet M5. Therefore, the fifth magnet M5 and the twelfth magnet M12 are permanent magnets belonging to the same group. The group to which the fifth magnet M5 and the twelfth magnet M12 belong is called the fifth group. The thirteenth magnet M13 is disposed at a position shifted by 180° from the sixth magnet M6. Therefore, the sixth magnet M6 and the thirteenth magnet M13 are permanent magnets belonging to the same group. The group to which the sixth magnet M6 and the thirteenth magnet M13 belong is called the sixth group. The fourteenth magnet M14 is disposed at a position shifted by 180° from the seventh magnet M7. Therefore, the seventh magnet M7 and the fourteenth magnet M14 are permanent magnets belonging to the same group. The group to which the seventh magnet M7 and the fourteenth magnet M14 belong is referred to as the seventh group.

[0026] In at least one of the multiple groups, the surface magnetic flux of the permanent magnets M belonging to the same group is different. Note that the surface magnetic flux is the magnetic flux density multiplied by the area. If the shape of all the permanent magnets M is the same, the area is the same for all the permanent magnets M. Therefore, if the shape of all the permanent magnets M is the same, and if the magnetic flux density of the permanent magnets M belonging to the same group is different in at least one of the multiple groups, it can be said that the surface magnetic flux of the permanent magnets M belonging to the same group is different. Also, the total value of the surface magnetic flux of the permanent magnets M belonging to the same group is the same for each group.

[0027] In this embodiment, among the first to seventh groups, the magnetic flux density of the permanent magnets M is different in the first group. In the second to seventh groups, the magnetic flux density of the permanent magnets M belonging to the same group is the same. Specifically, the magnetic flux density B1 of the first magnet M1 belonging to the first group is 1.3 [Wb / m 2 ], whereas the magnetic flux density B8 of the eighth magnet M8 is 1.1 [Wb / m 2 The magnetic flux densities B2 to B7 of the second to seventh magnets M2 to M7 and the magnetic flux densities B9 to B14 of the ninth to fourteenth magnets M9 to M14 are 1.2 [Wb / m 2 ].

[0028] As described above, in this embodiment, the shape of all the permanent magnets M is the same. Therefore, in this embodiment, among the first to seventh groups, the surface magnetic flux of the permanent magnets M is different in the first group. In the second to seventh groups, the surface magnetic flux of the permanent magnets M belonging to the same group is the same. Specifically, when the surface area of ​​each permanent magnet M is defined as A [m 2 ], the surface magnetic flux φ1 of the first magnet M1 is 1.3 A [Wb]. The surface magnetic flux φ8 of the eighth magnet M8 is 1.1 A [Wb]. The surface magnetic fluxes φ2 to φ7 of the second to seventh magnets M2 to M7 and the surface magnetic fluxes φ9 to φ14 of the ninth to fourteenth magnets M9 to M14 are each 1.2 A [Wb].

[0029] The sum Φ1 of the surface magnetic flux φ1 of the first magnet M1 belonging to the first group and the surface magnetic flux φ1 of the eighth magnet M8 is 1.4 A [Wb]. The sum Φ2 of the surface magnetic flux φ2 of the second magnet M2 belonging to the second group and the surface magnetic flux φ9 of the ninth magnet M9 is 1.4 A [Wb]. The sum Φ3 of the surface magnetic flux φ3 of the third magnet M3 belonging to the third group and the surface magnetic flux φ10 of the tenth magnet M10 is 1.4 A [Wb]. The sum Φ4 of the surface magnetic flux φ4 of the fourth magnet M4 belonging to the fourth group and the surface magnetic flux φ11 of the eleventh magnet M11 is 1.4 A [Wb]. The sum Φ5 of the surface magnetic flux φ5 of the fifth magnet M5 belonging to the fifth group and the surface magnetic flux φ12 of the twelfth magnet M12 is 1.4 A [Wb]. The sum Φ6 of the surface magnetic flux φ6 of the sixth magnet M6 belonging to the sixth group and the surface magnetic flux φ13 of the thirteenth magnet M13 is 1.4 A [Wb]. The sum Φ7 of the surface magnetic flux φ7 of the seventh magnet M7 belonging to the seventh group and the surface magnetic flux φ14 of the fourteenth magnet M14 is 1.4 A [Wb]. Therefore, Φ1 = Φ2 = Φ3 = Φ4 = Φ5 = Φ6 = Φ7. In other words, the sum of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same for each of the first to seventh groups.

[0030] <<Manufacturing method for rotating electrical machines>> The manufacturing method of the rotating electric machine 10 includes an acquisition step and an arrangement step. <Acquisition process> The acquisition step is a step of acquiring the magnetic flux density or surface magnetic flux for each of the multiple permanent magnets M used in the rotating electric machine 10. In this embodiment, an operator measures the magnetic flux density for each of the 14 permanent magnets M to acquire the magnetic flux density of each permanent magnet M. In this embodiment, of the 14 permanent magnets M, 1.1 [Wb / m 2 ] permanent magnet M, 1.2 [Wb / m 2 ] permanent magnet M 12 pieces, 1.3 [Wb / m 2 ] the result is one permanent magnet M.

[0031] <Placement process> The arranging step is a step of arranging a plurality of permanent magnets M based on the magnetic flux density or surface magnetic flux of the permanent magnets M acquired in the acquiring step. As described above, for the plurality of permanent magnets M, when the smallest prime factor of S / 6 is Z, the permanent magnets M arranged every (360 / S)×3×Z [°] are regarded as permanent magnets belonging to the same group. In the arranging step, the plurality of permanent magnets M are arranged such that in at least one group, the surface magnetic fluxes of the permanent magnets M belonging to the same group are different, and the total value of the permanent magnets M belonging to the same group is the same in each group.

[0032] Specifically, the multiple permanent magnets M are arranged so that a permanent magnet M having a magnetic flux density or surface magnetic flux greater than the average value of the magnetic flux density or surface magnetic flux of the multiple permanent magnets M and a permanent magnet M having a magnetic flux density or surface magnetic flux less than the average value belong to the same group. As a result, in at least one of the multiple groups, the surface magnetic flux of the permanent magnets M belonging to the same group is different. Also, the total value of the surface magnetic flux of the permanent magnets M belonging to the same group is the same for each group.

[0033] In this embodiment, the average value of the magnetic flux density of the 14 permanent magnets M is 1.2 [Wb / m 2 ]. Therefore, 1.1 [Wb / m 2 ] permanent magnet M is a permanent magnet whose magnetic flux density is smaller than the average value. 1.3 [Wb / m 2 ] is a permanent magnet whose magnetic flux density is greater than the average value. Therefore, in this embodiment, the magnetic flux density of 1.1 [Wb / m 2 ] permanent magnet M and 1.3 [Wb / m 2 The permanent magnets M are arranged so that the permanent magnets M with a magnetic flux density of 1.1 [Wb / m 2 ] permanent magnet M and 1.3 [Wb / m 2 ] belongs to the first group, so that the permanent magnet M of 1.1 [Wb / m 2 ] permanent magnet M is arranged as the first magnet M1 and has a magnetic field of 1.3 [Wb / m 2 ] is placed as the eighth magnet M8. And, 1.2 [Wb / m 2The permanent magnets M in the first to seventh groups are arranged as the second to seventh magnets M2 to M7 and the ninth to fourteenth magnets M9 to M14. As a result, the surface magnetic fluxes of the permanent magnets M belonging to the first group are different. Also, the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same for each of the first to seventh groups.

[0034] The operation of this embodiment will be described. In the case of non-fractional slots, the combination of the teeth 24 and the opposing permanent magnets M is the same for each electrical angle period. Therefore, even if the surface magnetic flux of the permanent magnets M varies, the flux linkage does not change for each electrical angle period.

[0035] On the other hand, in the case of fractional slots, the combination of the teeth 24 and the opposing permanent magnets M varies for each electrical angle period. For this reason, in conventional rotating electric machines, if the surface magnetic flux of the permanent magnets M varies, the flux linkage changes for each electrical angle period. As a result, the torque value differs for each electrical angle during one mechanical angle period, causing pulsation of the cogging torque.

[0036] When the rotor 12 has 5n poles, five electrical angle cycles make up one mechanical angle cycle, and therefore there are five combinations of the teeth 24 and the opposing permanent magnets M. Thus, pulsations corresponding to five electrical angle cycles occur during one mechanical angle cycle. When the rotor 12 has 7n poles, seven electrical angle cycles make up one mechanical angle cycle, and therefore there are seven combinations of the teeth 24 and the opposing permanent magnets M. Thus, pulsations corresponding to seven electrical angle cycles occur during one mechanical angle cycle.

[0037] 2 is a graph showing changes in torque over time in Comparative Example 1. Comparative Example 1 is a case in which the magnetic flux density of the first magnet M1 is higher than the magnetic flux density of each of the second to fourteenth magnets M2 to M14. In this case, as described above, pulsation corresponding to five electrical angle cycles occurs during one mechanical angle cycle.

[0038] 3 is a graph showing the change in torque over time in Comparative Example 2. Comparative Example 2 is a case where the magnetic flux density of each of the first magnet M1 and the eighth magnet M8 is higher than that of each of the second to seventh magnets M2 to M7 and the ninth to fourteenth magnets M9 to M14. In this case, as in Comparative Example 1, pulsation corresponding to seven electrical angle periods occurs during one mechanical angle period. In addition, not only the magnetic flux density of the first magnet M1 but also that of the eighth magnet M8 is higher than that of each of the second to seventh magnets M2 to M7 and the ninth to fourteenth magnets M9 to M14, so the difference in the interlinkage magnetic flux per electrical angle period is larger than that in Comparative Example 1. Therefore, the pulsation of the cogging torque is more prominent than that in Comparative Example 1.

[0039] 4 is a graph showing the change in torque over time in this embodiment. In this embodiment, in the arrangement step, the multiple permanent magnets M are arranged so that the permanent magnets M having a higher magnetic flux density than the average magnetic flux density of the multiple permanent magnets M and the permanent magnets M having a lower magnetic flux density than the average magnetic flux density belong to the same group. Therefore, the surface magnetic fluxes of the permanent magnets M belonging to the same group are different. Furthermore, the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same for each group. Therefore, even if the surface magnetic flux of the permanent magnets M varies, the linkage magnetic flux is the same for each electrical angle period, so the difference in the linkage magnetic flux for each electrical angle period is small. Therefore, the pulsation of the cogging torque is reduced.

[0040] The effects of the first embodiment will be described. (1) For multiple permanent magnets M, when the smallest prime factor of S / 6 is Z, the permanent magnets M arranged every θv=(360 / S)×3×Z [°] are considered to belong to the same group. In at least one group, the surface magnetic flux of the permanent magnets M belonging to the same group is different. The total value of the surface magnetic flux of the permanent magnets M belonging to the same group is the same in each group. As a result, the flux linkage is the same for each electrical angle cycle, and the difference in flux linkage for each electrical angle cycle is small. This makes it possible to reduce the pulsation of the cogging torque.

[0041] (2) For example, when the surface magnetic flux of all permanent magnets M is the same, the pulsation of the cogging torque is reduced the most. However, in this case, it is not possible to use a permanent magnet M with a larger or smaller surface magnetic flux than the other permanent magnets M, which occurs during the manufacture of the permanent magnets M. In contrast, in this embodiment, even if the surface magnetic flux of the permanent magnets M varies, the arrangement of the permanent magnets M is devised to reduce the pulsation of the cogging torque. Therefore, it is possible to reduce the pulsation of the cogging torque while using a permanent magnet M with a larger or smaller surface magnetic flux than the other permanent magnets M.

[0042] [Second embodiment] A second embodiment embodying a rotating electric machine and a manufacturing method thereof will be described below with reference to Fig. 5. Note that the configuration other than the rotor 12 is similar to that of the first embodiment, and therefore description thereof will be omitted.

[0043] As shown in Fig. 5, rotor core 26 has a plurality of magnet insertion holes 27. The plurality of magnet insertion holes 27 are aligned in the circumferential direction of rotor core 26. Each magnet insertion hole 27 penetrates rotor core 26 in the axial direction. Magnet insertion holes 27 are S-pole magnet insertion holes into which an S-pole magnet is inserted, or N-pole magnet insertion holes into which an N-pole magnet is inserted. The S-pole magnet insertion holes and N-pole magnet insertion holes are aligned alternately in the circumferential direction of rotor core 26.

[0044] Each magnet insertion hole 27 is composed of two insertion hole constituent parts 27a. The two insertion hole constituent parts 27a are lined up in the circumferential direction of the rotor core 26. In this embodiment, the two insertion hole constituent parts 27a are arranged in a V shape. More specifically, the distance between the two insertion hole constituent parts 27a in the circumferential direction of the rotor core 26 becomes longer toward the radial outside of the rotor core 26.

[0045] Each permanent magnet M is composed of two magnet constituent bodies Ma. Each magnet constituent body Ma is flat plate-shaped. The magnetization direction of each magnet constituent body Ma coincides with the plate thickness direction of each magnet constituent body Ma. Each magnet constituent body Ma is inserted into the insertion hole constituent portion 27a. Therefore, the rotor 12 of this embodiment is an IPM (Interior Permanent Magnet) type rotor in which the permanent magnets M are embedded inside the rotor core 26.

[0046] The two magnet constituent bodies Ma are arranged in the circumferential direction of the rotor core 26 by being inserted into the magnet insertion holes 27. In this embodiment, the two magnet constituent bodies Ma are arranged in a V-shape by being inserted into the magnet insertion holes 27. In particular, the distance between the two magnet constituent bodies Ma in the circumferential direction of the rotor core 26 becomes longer toward the radially outer side of the rotor core 26. The two magnet constituent bodies Ma constituting the S-pole magnet are arranged such that their S poles face each other in the circumferential direction of the rotor core 26. The two magnet constituent bodies Ma constituting the N-pole magnet are arranged such that their N poles face each other in the circumferential direction of the rotor core 26.

[0047] The second embodiment differs from the first embodiment in that each permanent magnet M is composed of two magnet constituent bodies Ma, but the arrangement of the multiple permanent magnets M is the same as that of the first embodiment. That is, in at least one group, the surface magnetic fluxes of the permanent magnets M belonging to the same group are different. Also, the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same for each group.

[0048] In the second embodiment, "the surface magnetic fluxes of the permanent magnets M belonging to the same group are different" includes cases where the surface magnetic fluxes of two magnet constituent bodies Ma constituting a permanent magnet M are different from the surface magnetic fluxes of two magnet constituent bodies Ma constituting other permanent magnets M belonging to the same group. In other words, as long as the surface magnetic fluxes of two magnet constituent bodies Ma constituting permanent magnets M belonging to the same group are different, the total value of the surface magnetic fluxes of the two magnet constituent bodies Ma constituting permanent magnets M belonging to the same group may be the same.

[0049] For example, if the surface magnetic flux of each of the two magnet constituent bodies Ma constituting the first magnet M1 is 1.3 A [Wb], the total value of the surface magnetic flux of the two magnet constituent bodies Ma constituting the first magnet M1 is 2.6 A [Wb]. Also, if the magnetic flux density of each of the two magnet constituent bodies Ma constituting the eighth magnet M8 is 1.1 A [Wb], the total value of the magnetic flux density of the two magnet constituent bodies Ma constituting the eighth magnet M8 is 2.2 A [Wb]. In this case, it can be said that the surface magnetic flux of the first magnet M1 belonging to the first group is different from the surface magnetic flux of the eighth magnet M8.

[0050] As another example, of the two magnet constituent bodies Ma constituting the first magnet M1, the surface magnetic flux of one magnet constituent body Ma is 1.3 A [Wb], and the surface magnetic flux of the other magnet constituent body Ma is 1.1 A [Wb]. In this case, the total value of the surface magnetic flux of the two magnet constituent bodies Ma constituting the first magnet M1 is 2.4 A [Wb]. Also, of the two magnet constituent bodies Ma constituting the eighth magnet M8, the surface magnetic flux of one magnet constituent body Ma is 1.3 A [Wb], and the surface magnetic flux of the other magnet constituent body Ma is 1.1 A [Wb]. In this case, the total value of the surface magnetic flux of the two magnet constituent bodies Ma constituting the eighth magnet M8 is 2.4 A [Wb]. In this case, the total value of the surface magnetic flux of the two magnet constituent bodies Ma constituting the first magnet M1 is the same as the total value of the surface magnetic flux of the two magnet constituent bodies Ma constituting the eighth magnet M8. However, the surface magnetic flux of the two magnet constituent bodies Ma that make up the first magnet M1 is different from the surface magnetic flux of the two magnet constituent bodies Ma that make up the eighth magnet M8. Therefore, this includes the case where the surface magnetic flux of the first magnet M1 and the surface magnetic flux of the eighth magnet M8 that belong to the first group are different.

[0051] In the second embodiment, it is possible to obtain the same effects as the effects (1) and (2) of the first embodiment. The above embodiment may be modified as follows: The above embodiment and modifications may be combined with each other to the extent that no technical contradiction occurs.

[0052] In the case of a fractional slot rotating electric machine in which the number S of slots 25 is a multiple of 6 that is greater than or equal to 12, and q is a fraction such that q<½, the number of poles of the rotor 12, the number S of slots 25, and the number of phases of the coils 22 may be changed as appropriate.

[0053] For example, the rotating electric machine 10 may include a three-phase 18-slot stator 11 and a 16-pole rotor 12. In this case, q=18 / (16×3)=3 / 8. In addition, since S / 6=3 and Z=3, θv=(360 / 18)×3×3=180[°]. For the 16 permanent magnets M, the permanent magnets M arranged every 180[°] belong to the same group. Therefore, the 16 permanent magnets M are divided into eight groups. Two permanent magnets M belong to each group. The 16 permanent magnets M are arranged such that the surface magnetic fluxes of the permanent magnets M belonging to the same group are different in at least one group, and the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same in all eight groups.

[0054] For example, the rotating electric machine 10 may include a three-phase 24-slot stator 11 and a 20-pole rotor 12. In this case, q=24 / (20×3)=2 / 5. In addition, since S / 6=4 and Z=2, θv=(360 / 24)×3×2=90[°]. For the 20 permanent magnets M, the permanent magnets M arranged every 90[°] belong to the same group. Therefore, the 20 permanent magnets M are divided into five groups. Each group includes four permanent magnets M. The 20 permanent magnets M are arranged such that the surface magnetic fluxes of the permanent magnets M belonging to the same group are different in at least one group, and the total value of the surface magnetic fluxes of the permanent magnets M belonging to the same group is the same in all five groups.

[0055] In the above embodiment, 1.1 [Wb / m 2 ] of permanent magnet M and 1.3 [Wb / m 2 The permanent magnets M in the first group may be arranged in a group other than the first group, so long as they are arranged so as to belong to the same group.

[0056] The number of permanent magnets M having a surface magnetic flux or magnetic flux density greater than the average value of the surface magnetic flux or magnetic flux density of the multiple permanent magnets M, and the number of permanent magnets M having a surface magnetic flux or magnetic flux density less than the average value of the surface magnetic flux or magnetic flux density of the multiple permanent magnets M do not have to be one each. However, it is preferable that the number of permanent magnets M having a surface magnetic flux or magnetic flux density greater than the average value of the surface magnetic flux or magnetic flux density of the multiple permanent magnets M is the same as the number of permanent magnets M having a surface magnetic flux or magnetic flux density less than the average value.

[0057] For example, of the 14 permanent magnets, M, 1.2 [Wb / m 2 ] permanent magnet M 10 pieces, 1.0 [Wb / m 2 ], 1.1 [Wb / m 2 ], 1.3 [Wb / m 2 ], 1.4 [Wb / m 2 In this case, the permanent magnets M are arranged as follows:

[0058] The average magnetic flux density of 14 permanent magnets M is 1.2 [Wb / m 2 ]. Therefore, 1.0 [Wb / m 2 ] of permanent magnet M, and 1.1 [Wb / m 2 ] is a permanent magnet M whose magnetic flux density is lower than the average value. 2 ] of permanent magnet M, and 1.4 [Wb / m 2 ] is a permanent magnet M with a magnetic flux density higher than the average value. Therefore, the permanent magnet M with the lowest magnetic flux density of 1.0 [Wb / m 2 ] permanent magnet M and the highest magnetic flux density of 1.4 [Wb / m 2 ] are arranged so that they belong to the same group as permanent magnet M. The second lowest magnetic flux density is 1.1 [Wb / m 2 ] permanent magnet M, with the second highest magnetic flux density of 1.3 [Wb / m 2 ] are arranged so that they belong to the same group as the permanent magnet M. 1.2 [Wb / m 2 ] are arranged so that they belong to the same group.

[0059] Specifically, 1.0 [Wb / m 2 ] is placed as the first magnet M1, the 2 ] is arranged as the eighth magnet M8. 2 ] is placed as the ninth magnet M9, 1.3 [Wb / m 2 ] permanent magnet M is arranged as the second magnet M2. Furthermore, 1.2 [Wb / m 2 The permanent magnets M in the row 11-13 are arranged as third to sixth magnets M3 to M6 and tenth to fourteenth magnets M10 to M14.

[0060] For example, out of 14 permanent magnets, M, 1.1 [Wb / m 2 ], 1.3 [Wb / m 2 In this case, the permanent magnets M are arranged as follows: The average magnetic flux density of 14 permanent magnets M is 1.2 [Wb / m 2 ]. Therefore, 1.1 [Wb / m 2 ] is a permanent magnet M whose magnetic flux density is smaller than the average value. 1.3 [Wb / m 2 ] permanent magnet M is a permanent magnet M with a magnetic flux density greater than the average value. Therefore, the magnetic flux density of 14 permanent magnets M is 1.1 [Wb / m 2 ] permanent magnet M and 1.3 [Wb / m 2 For example, 1.1 [Wb / m 2 ] are arranged as the first to seventh magnets M1 to M7. 1.3 [Wb / m 2 The permanent magnets M in the row 11 to 14 are arranged as the eighth to fourteenth magnets M8 to M14.

[0061] ○ The total value of the surface magnetic flux of the permanent magnets M belonging to the same group does not have to be completely the same for each group. "The total value of the surface magnetic flux of the permanent magnets belonging to the same group is the same for each group" also includes the case where the total value of the surface magnetic flux of the permanent magnets belonging to the same group is slightly different for each group within the range in which cogging torque pulsation is allowed. For example, it is sufficient that the variation (standard deviation) of the "sum of the surface magnetic flux of the permanent magnets M belonging to the same group" when the permanent magnets M are grouped and arranged so that the total value of the surface magnetic flux of the permanent magnets M belonging to the same group is the same, as in the present invention, is smaller than the variation (standard deviation) of the "sum of the surface magnetic flux of the permanent magnets M belonging to the same group" when the permanent magnets M are arranged randomly regardless of the surface magnetic flux of each permanent magnet M.

[0062] The yoke 23 does not have to be cylindrical. For example, the yoke 23 may be in the shape of a polygonal tube. The rotor core 26 does not have to be cylindrical. The rotor core 26 may be, for example, polygonal tubular.

[0063] In the second embodiment, the two magnet configurations Ma do not have to be arranged in a V-shape as long as they are aligned in the circumferential direction of the rotor core 26. In the obtaining step, for each of the plurality of permanent magnets M, the surface magnetic flux may be measured instead of the magnetic flux density.

[0064] In the obtaining step, the magnetic flux density of each of the plurality of permanent magnets M may be obtained by obtaining data on the magnetic flux density or surface magnetic flux of each permanent magnet M that has been created in advance. [Explanation of symbols]

[0065] Reference Signs List 10: rotating electric machine, 11: stator, 12: rotor, 21: stator core, 22: coil, 23: yoke, 24: teeth, 25: slot, 26: rotor core, M: permanent magnet, Ma: magnet structure.

Claims

1. a stator including a cylindrical yoke, a plurality of teeth extending from the yoke in a radial direction of the yoke and spaced apart in a circumferential direction of the yoke, and a stator core having slots which are spaces between adjacent teeth in the circumferential direction of the yoke, and a coil wound in a concentrated winding manner around the teeth; A rotor having a cylindrical rotor core and a plurality of permanent magnets arranged in a circumferential direction of the rotor core; Equipped with The permanent magnets are S-pole magnets or N-pole magnets whose magnetization direction is different from that of the S-pole magnets, and the S-pole magnets and the N-pole magnets are alternately arranged in the circumferential direction of the rotor core, a number S of the slots being a multiple of 6 that is equal to or greater than 12, and when q=S / (number of poles of the rotor×number of phases of the coil), q is a fraction and q<1 / 2; Let Z be the smallest prime factor of S / 6, and let the permanent magnets arranged every (360 / S)×3×Z [°] belong to the same group. In at least one group, the surface magnetic fluxes of the permanent magnets belonging to the same group are different, A rotating electric machine, characterized in that a total value of surface magnetic flux of the permanent magnets belonging to the same group is the same in each group.

2. 2. The rotating electric machine according to claim 1, wherein each of the plurality of permanent magnets is formed of two magnet components arranged in a circumferential direction of the rotor core.

3. a stator including a cylindrical yoke, a plurality of teeth extending from the yoke in a radial direction of the yoke and spaced apart in a circumferential direction of the yoke, and a stator core having slots which are spaces between adjacent teeth in the circumferential direction of the yoke, and a coil wound in a concentrated winding manner around the teeth; A rotor having a cylindrical rotor core and a plurality of permanent magnets arranged in a circumferential direction of the rotor core; Equipped with The permanent magnets are S-pole magnets or N-pole magnets whose magnetization direction is different from that of the S-pole magnets, and the S-pole magnets and the N-pole magnets are alternately arranged in the circumferential direction of the rotor core, a number S of the slots being a multiple of 6 that is equal to or greater than 12, and q being a fraction such that q<1 / 2 when q=S / (number of poles of the rotor×number of phases of the coils), acquiring a surface magnetic flux or a magnetic flux density for each of the plurality of permanent magnets; an arrangement step of arranging the plurality of permanent magnets based on the surface magnetic flux or the magnetic flux density of the permanent magnets acquired in the acquisition step; having In the placing step, Let Z be the smallest prime factor of S / 6, and let the permanent magnets arranged every (360 / S)×3×Z [°] belong to the same group. A manufacturing method for a rotating electric machine, characterized in that a plurality of permanent magnets are arranged so that, in at least one group, the surface magnetic flux of the permanent magnets belonging to the same group is different, and the total value of the surface magnetic flux of the permanent magnets belonging to the same group is the same in each group.

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