Rotor and rotary electric machine

Abstract

To provide a rotor and a rotary electric machine which allow improvement in strength of a rotor core against vibration in an axial direction.SOLUTION: Each of a plurality of core sheets 30 forming a rotor core 22 has a first magnet through-hole 31 and a second magnet through-hole 32. A magnet housing hole 24 is formed by providing the first magnet through-hole 31 and the second magnet through-hole 32 in a manner overlapping each other in an axial direction. An inner surface of the magnet housing hole 24 is provided with a first recess / protrusion part 43, a second recess / protrusion part 44, and a third recess / protrusion part 45 which are formed by a positional difference between peripheral edges of the first magnet through-hole 31 and the second magnet through-hole 32. The inner surface of the magnet housing hole 24 is also provided with a non-recessed / protruding part 46 where none of the first recess / protrusion part 43, the second recess / protrusion part 44, and the third recess / protrusion part 45 is formed. A permanent magnet 23 has engaging parts each of which enters a recess of each of the first recess / protrusion part 43, the second recess / protrusion part 44, and the third recess / protrusion part 45.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an embedded magnet type rotor and a rotating electric machine. [Background technology]

[0002] In a rotating electric machine, an embedded magnet type rotor in which permanent magnets are embedded inside a rotor core is well known. The embedded magnet type rotor is configured to obtain a reluctance torque from an outer core portion located radially outward of the permanent magnets in addition to a magnet torque from the permanent magnets.

[0003] In such embedded magnet rotors, for example, the rotor described in Patent Document 1 has permanent magnets folded in a V-shape or U-shape, convex toward the inside in the radial direction, when viewed in the axial direction. In this configuration, it is possible to increase the size of the magnet surface of the permanent magnet in contact with the outer core portion and the outer core portion itself. In other words, it is expected that the torque of the rotating electric machine will be increased. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-70032 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the rotor using the permanent magnet having a folded shape that is convex radially inward as described above, the volume of the outer core portion located radially outside the permanent magnet becomes large. In addition, if the radially outer end of the permanent magnet is extended close to the outer peripheral surface of the rotor core in order to increase the torque, the thickness of the bridge portion, which is the part of the rotor core between the radially outer end of the permanent magnet and the outer peripheral surface of the rotor core, becomes thin, and the strength of the bridge portion decreases. For this reason, for example, when an axial vibration force is applied to the rotor due to an external factor, the outer core portion may vibrate in the axial direction with the bridge portion as a fulcrum. If the vibration of the outer core portion becomes large, the rotor core may be deformed. An object of the present invention is to provide a rotor and a rotating electric machine that make it possible to improve the strength of the rotor core against axial vibration. [Means for solving the problem]

[0006] A rotor that solves the above problem is a rotor (20) including a rotor core (22) having a plurality of magnet accommodating holes (24) that form a convex folded shape radially inward, and permanent magnets (23) embedded in the magnet accommodating holes, wherein the rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, each of the plurality of core sheets has a magnet through hole (31, 32), the magnet accommodating holes are formed by the magnet through holes of the plurality of core sheets overlapping in the axial direction, the inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by the difference in position of the peripheral portions of the magnet through holes that overlap in the axial direction, and the permanent magnets have engagement portions (51, 52, 53) that fit into the recesses (43a, 44a, 45a) of the uneven portions.

[0007] A rotating electric machine that solves the above problem is a rotating electric machine (M) that includes a rotor (20) having a rotor core (22) having a plurality of magnet accommodating holes (24) that form a convex folded shape radially inward, and permanent magnets (23) embedded in the magnet accommodating holes, and a stator (10) that imparts a rotating magnetic field to the rotor, wherein the rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, each of the plurality of core sheets has a magnet through hole (31, 32), the magnet accommodating hole is formed by the magnet through holes of the plurality of core sheets overlapping in the axial direction, the inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by the difference in position of the peripheral portions of the magnet through holes that overlap in the axial direction, and the permanent magnets have engagement portions (51, 52, 53) that fit into the recesses (43a, 44a, 45a) of the uneven portions. [Brief description of the drawings]

[0008] [Figure 1] 1 is a configuration diagram of a rotating electric machine having an embedded magnet type rotor according to an embodiment; [Diagram 2] FIG. [Diagram 3] Cross-sectional view taken along line III-III in FIG. 2. [Figure 4] Cross-sectional view taken along line IV-IV in FIG. 2. [Diagram 5] 13(a) and (b) are plan views of a core sheet used in a rotor in the same configuration. [Figure 6] FIG. 11 is a cross-sectional view of a rotor in a modified example. [Figure 7] FIG. 11 is a cross-sectional view of a rotor in a modified example. [Figure 8] FIG. 11 is a cross-sectional view of a rotor in a modified example. [Figure 9] FIG. 11 is a cross-sectional view of a rotor in a modified example. [Figure 10] FIG. 11 is a plan view of a rotor in a modified example. [Figure 11] Cross-sectional view taken along line XI-XI in Figure 10. [Figure 12] FIG. 11 is a plan view of a rotor in a modified example. [Figure 13]Cross-sectional view taken along line XIII-XIII in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the rotor and the rotating electric machine will be described below. The rotating electric machine M of this embodiment shown in Fig. 1 is configured as an embedded magnet type brushless motor. The rotating electric machine M includes a substantially annular stator 10 and a substantially cylindrical rotor 20 rotatably disposed in a radially inner space of the stator 10. The stator 10 applies a rotating magnetic field to the rotor 20.

[0010] The stator 10 includes a stator core 11 having a substantially circular ring shape. The stator core 11 is made of a magnetic metal material, for example, a laminate of a plurality of electromagnetic steel sheets. The stator core 11 has 12 teeth 12 extending radially inward and arranged at equal intervals in the circumferential direction in this embodiment. The teeth 12 have the same shape as each other. The radially inner end of the teeth 12, which is the tip portion, is substantially T-shaped, and the tip surface 12a is an arc shape following the outer circumferential surface of the rotor 20. The windings 13 are wound around the 12 teeth 12 by concentrated winding. That is, the number of magnetic poles of the stator 10 is "12". The windings 13 are connected in a three-phase manner, and function as U-phase, V-phase, and W-phase, respectively, as shown in FIG. 1. When power is supplied to the windings 13, a rotating magnetic field for rotating the rotor 20 is generated in the stator 10. In the stator 10 as described above, the outer peripheral surface of the stator core 11 is fixed to the inner peripheral surface of the housing 14 .

[0011] (Rotor core 22) The rotor 20 includes a rotating shaft 21, a substantially cylindrical rotor core 22 into whose center the rotating shaft 21 is fitted, and eight permanent magnets 23 in this embodiment that are embedded inside the rotor core 22. In other words, the rotor 20 has eight magnetic poles. The rotor 20 is rotatably disposed with respect to the stator 10 with the rotating shaft 21 supported by a bearing (not shown) provided in the housing 14.

[0012] As shown in Fig. 2, the rotor core 22 has magnet accommodating holes 24 for accommodating the permanent magnets 23. In this embodiment, eight magnet accommodating holes 24 are provided at equal intervals in the circumferential direction of the rotor core 22. Each magnet accommodating hole 24 penetrates the rotor core 22 along the axial direction, for example. When viewed from the axial direction, each magnet accommodating hole 24 has a generally V-shaped folded shape that protrudes radially inward. That is, each magnet accommodating hole 24 has, for example, a pair of straight portions 24a that are linear when viewed from the axial direction, and a bent portion 24b that connects radially inner ends of the pair of straight portions 24a.

[0013] In each magnet accommodating hole 24, a radially outer end 24c of each straight portion 24a is located near the outer circumferential surface 22a of the rotor core 22. The bent portion 24b is located near the shaft insertion hole 22b at the center of the rotor core 22, into which the rotating shaft 21 is inserted. The bent portion 24b is located within a reference circle C1 having a diameter half the outer diameter of the rotor core 22. The reference circle C1 is a circle centered on the axis L of the rotor 20. The radially outer end 24c of the straight portion 24a is located outside the reference circle C1. The magnet accommodating holes 24 are provided throughout the entire axial direction of the rotor core 22.

[0014] (Permanent magnet 23) In this embodiment, the permanent magnet 23 is a bonded magnet obtained by molding and solidifying a magnetic material made by mixing magnetic powder with resin. That is, the permanent magnet 23 is formed by using the magnet accommodating hole 24 of the rotor core 22 as a molding die, filling the magnet accommodating hole 24 with unsolidified magnetic material by injection molding without gaps, and solidifying the material in the magnet accommodating hole 24 after filling. Therefore, the hole shape of the magnet accommodating hole 24 is the outer shape of the permanent magnet 23. As the magnetic powder used for the permanent magnet 23 in this embodiment, for example, a samarium iron nitrogen (SmFeN) magnet is used, but other rare earth magnets, etc. may also be used.

[0015] As shown in FIG. 2, the permanent magnet 23 is formed directly in the magnet accommodating hole 24, and therefore has a shape corresponding to the magnet accommodating hole 24, that is, a folded shape of a generally V-shape convex toward the radially inward direction when viewed in the axial direction. The permanent magnet 23 has a pair of straight portions 23a and a bent portion 23b connecting the radially inner ends of the pair of straight portions 23a. The straight portion 23a of the permanent magnet 23 is located within the straight portion 24a of the magnet accommodating hole 24. The bent portion 23b of the permanent magnet 23 is located within the bent portion 24b of the magnet accommodating hole 24. The radially outer end of the straight portion 23a is located near the outer circumferential surface 22a of the rotor core 22. The permanent magnet 23 has, for example, an axisymmetric shape with respect to its own circumferential center line Ls passing through the axis L of the rotor 20.

[0016] As shown in FIG. 1, a portion of the rotor core 22 located inside the V-shaped folded shape of the permanent magnet 23 and radially outside the permanent magnet 23 functions as an outer core portion 25 for obtaining reluctance torque by facing the stator 10. The outer core portion 25 has a substantially triangular shape with one apex facing the center direction of the rotor 20 when viewed in the axial direction. The rotor 20 has a plurality of magnetic pole portions 26 including the permanent magnet 23 and the outer core portion 25. The number of the magnetic pole portions 26 is the same as the number of the permanent magnets 23, and is eight in this embodiment. That is, the rotor 20 has eight poles. The plurality of magnetic pole portions 26 have the same shape as each other. In this embodiment, the magnetic pole opening angle θm of each magnetic pole portion 26 is 45° in mechanical angle. The plurality of magnetic pole portions 26 are arranged at equal intervals in the circumferential direction. The rotor 20 also has eight magnetic pole boundary lines Ld that are boundaries between adjacent magnetic pole portions 26. Each magnetic pole boundary line Ld is a line passing through the axis L of the rotor 20. Each magnetic pole portion 26 functions as an N pole or an S pole, as shown in an example in Fig. 1. The rotor 20 is configured such that both magnet torque and reluctance torque can be obtained at such magnetic pole portions 26.

[0017] The permanent magnets 23, which are provided in a substantially embedded manner in the magnet accommodating holes 24 of the rotor core 22, are magnetized from the outside of the rotor core 22 using a magnetizing device (not shown) so that the magnets function as their original magnets after the magnetic material has solidified. In this case, each permanent magnet 23 is magnetized in its own thickness direction. In this embodiment, eight permanent magnets 23 are provided in the circumferential direction of the rotor core 22, and are magnetized so that the polarities are alternately different in the circumferential direction.

[0018] As shown in FIG. 2, the inner surface of the magnet accommodating hole 24 is in contact with the permanent magnet 23. The inner surface of the magnet accommodating hole 24 includes an inner side surface 41 and an outer side surface 42. The inner side surface 41 is a side surface constituting the outer core portion 25 and is a surface that is in contact with the inside of the V-shaped folded shape of the permanent magnet 23. The outer side surface 42 is a side surface that faces the inner side surface 41 in the hole width direction. The hole width direction of the magnet accommodating hole 24 is a direction perpendicular to the extension direction of the magnet accommodating hole 24 when viewed in the axial direction. The extension direction of the magnet accommodating hole 24 is a direction along the approximately V-shaped folded shape when the magnet accommodating hole 24 is viewed from the axial direction. Each of the inner side surface 41 and the outer side surface 42 is a surface that follows the folded shape of the magnet accommodating hole 24 when viewed in the axial direction.

[0019] The inner side surface 41 has a first uneven portion 43. The outer side surface 42 has a second uneven portion 44. The first uneven portion 43 is provided on the inner side surface 41 at the bent portion 24b. The second uneven portion 44 is provided on the outer side surface 42 at the bent portion 24b. A third uneven portion 45 is provided on the inner surface of the magnet accommodating hole 24 at a portion corresponding to the radially outer end portion 24c of the straight portion 24a. The inner surface of the magnet accommodating hole 24 has a non-uneven portion 46 which is a portion where the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 are not formed. In this embodiment, the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 are formed partially in the extension direction of the magnet accommodating hole 24, and the non-uneven portion 46 is formed at other points in the extension direction of the magnet accommodating hole 24.

[0020] The rotor core 22 has bridge portions 22c located outside the radial outer ends 24c of each straight portion 24a. Each bridge portion 22c connects the outer core portion 25 to a portion of the rotor core 22 other than the outer core portion 25. In this embodiment, when the rotor core 22 is viewed alone, the outer core portion 25 is supported by two bridge portions 22c.

[0021] (Configuration of core sheet 30) The rotor core 22 is formed by stacking a plurality of core sheets 30 made of electromagnetic steel sheets in the axial direction L. The individual core sheets 30 have the same configuration as shown in FIG. 5(a). This makes it possible to manage each core sheet 30 as the same part. Note that the core sheet 30 shown in FIG. 5(b) appears to have a different shape from the core sheet 30 shown in FIG. 5(a), but in fact it is arranged at a second position rotated 45°, which is the amount of one magnet accommodating hole 24, in other words, one magnetic pole, from the first position shown in FIG. 5(a).

[0022] Two types of magnet through holes having different shapes are formed in each core sheet 30. In the following description, one of the two types of magnet through holes is referred to as a first magnet through hole 31, and the other is referred to as a second magnet through hole 32. The first magnet through holes 31 and the second magnet through holes 32 are alternately arranged at 45° intervals in the circumferential direction in each core sheet 30.

[0023] The first magnet through hole 31 and the second magnet through hole 32 each have a generally V-shaped folded shape that protrudes radially inward. That is, the first magnet through hole 31 has a shape in which the radially inner ends of a pair of straight portions 31a are connected to each other by a bent portion 31b. The second magnet through hole 32 has a shape in which the radially inner ends of a pair of straight portions 32a are connected to each other by a bent portion 32b.

[0024] In the process of stacking the core sheets 30 to form the rotor core 22, in this embodiment, the core sheets 30 are stacked one by one so that the core sheets 30 arranged in the first position shown in Fig. 5(a) and the core sheets 30 arranged in the second position rotated by 45° and shown in Fig. 5(b) are alternately stacked. As a result, the first magnet through holes 31 and the second magnet through holes 32 are alternately overlapped in the axial direction. Each magnet accommodating hole 24 is formed by the first magnet through holes 31 and the second magnet through holes 32 that overlap in the axial direction.

[0025] On the inner surface of the magnet accommodating hole 24, the first uneven portion 43, the second uneven portion 44 and the third uneven portion 45 are each formed by the difference in position of the peripheral portions of the first magnet through hole 31 and the second magnet through hole 32.

[0026] (First uneven portion 43 and second uneven portion 44) 3, the first uneven portion 43 and the second uneven portion 44 are formed by the difference in radial position between the bent portion 31b of the first magnet through hole 31 and the bent portion 32b of the second magnet through hole 32. In this embodiment, the radial width of each bent portion 31b is equal. The bent portion 31b of the first magnet through hole 31 is located radially outward of the bent portion 32b of the second magnet through hole 32.

[0027] The first uneven portion 43 has a plurality of recesses 43a in the axial direction. The permanent magnet 23 has an engagement portion 51 that fits into each recess 43a of the first uneven portion 43. Each engagement portion 51 is adapted to be hooked onto each recess 43a in the axial direction.

[0028] The second uneven portion 44 has a plurality of recesses 44a in the axial direction. The permanent magnet 23 has an engagement portion 52 that fits into each recess 44a of the second uneven portion 44. Each engagement portion 52 is adapted to be hooked onto each recess 44a in the axial direction. In this embodiment, the depth D1 of the recesses 43a of the first uneven portion 43 is set to a depth equal to the depth D2 of the recesses 44a of the second uneven portion 44 provided on the outer side surface 42. In addition, each of the depth D1 of the recesses 43a and the depth D2 of the recesses 44a gradually becomes shallower, for example, as it approaches the straight portion 24a.

[0029] (Third uneven portion 45) The third uneven portion 45 is formed by a difference in shape at the radially outer end of each of the straight portions 31a, 32a of the first magnet through hole 31 and the second magnet through hole 32. As shown in FIG. 5(a), a protruding portion 32c that protrudes inward in the hole width direction relative to the straight portion 31a is formed at the radially outer end of the straight portion 32a. The protruding portion 32c is formed at an inner corner portion of a V-shaped turn-back shape at the radially outer end of the straight portion 32a. The protruding portion 32c is formed by tapering the inner corner portion.

[0030] As shown in Fig. 4, the third uneven portion 45 is formed by overlapping a straight portion 32a having a protruding portion 32c and a straight portion 31a having no protruding portion in the axial direction. The third uneven portion 45 has a plurality of recesses 45a in the axial direction. The recesses 45a are composed of the straight portion 31a having no protruding portion. The permanent magnet 23 has an engagement portion 53 that enters each recess 45a of the third uneven portion 45. Each engagement portion 53 is adapted to be hooked onto each recess 45a in the axial direction.

[0031] 2, the non-convexoconcave portion 46 is a portion of the inner surface of the magnet accommodating hole 24 where the first concave-convex portion 43, the second concave-convex portion 44, and the third concave-convex portion 45 are not formed. That is, when the magnet accommodating hole 24 is viewed from the axial direction, in the non-convexoconcave portion 46, the positions of the peripheral portions of the first magnet through hole 31 and the second magnet through hole 32 that overlap in the axial direction are aligned.

[0032] The operation of the rotor 20 of the rotating electric machine M of this embodiment will be described. The permanent magnet 23, which is a bonded magnet filled in the magnet accommodating hole 24, engages with the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 of the magnet accommodating hole 24 in a manner similar to an anchor effect. That is, the outer core portion 25 engages with the V-shaped inner surface of the permanent magnet 23 in the axial direction by the first uneven portion 43 and the third uneven portion 45. Also, the V-shaped outer surface of the permanent magnet 23 engages with a portion of the rotor core 22 other than the outer core portion 25 in the axial direction by the second uneven portion 44. This makes it possible to suppress the outer core portion 25 from vibrating in the axial direction with the bridge portion 22c as a fulcrum, even if an axial vibration force is applied to the rotor 20 due to an external factor, for example.

[0033] Furthermore, a non-uneven portion 46 is provided on the inner surface of the magnet accommodating hole 24. In the non-uneven portion 46, unevenness such as the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 is not formed. This makes it possible to suppress axial leakage magnetic flux that occurs due to the boundary between the magnet accommodating hole 24 and the permanent magnet 23 being uneven, compared to a configuration in which the entire inner surface of the magnet accommodating hole 24 has uneven portions.

[0034] The effects of this embodiment will be described. (1) The inner surface of the magnet accommodating hole 24 is provided with a first uneven portion 43, a second uneven portion 44, and a third uneven portion 45 formed by the difference in the position of the peripheral portion of the first magnet through hole 31 and the second magnet through hole 32. The permanent magnet 23 has engagement portions 51, 52, and 53 that enter the recesses 43a, 44a, and 45a of the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45, respectively. According to this configuration, the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 are engaged with the engagement portions 51, 52, and 53 in the axial direction, respectively. This makes it possible to suppress axial vibration of the outer core portion 25. As a result, it is possible to suppress deformation of the bridge portion 22c and the outer core portion 25 in the rotor core 22. Therefore, it is possible to improve the strength of the rotor core 22 against axial vibration.

[0035] Furthermore, the inner surface of the magnet accommodating hole 24 is provided with a non-uneven portion 46 which is a portion where the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 are not formed. This makes it possible to suppress axial leakage magnetic flux that occurs due to the boundary between the magnet accommodating hole 24 and the permanent magnet 23 being uneven, compared to a configuration in which the entire inner surface of the magnet accommodating hole 24 has uneven portions.

[0036] (2) The inner surface of the magnet accommodating hole 24 includes an inner side surface 41 forming the outer core portion 25, and an outer side surface 42 facing the inner side surface 41. The inner side surface 41 is provided with a first uneven portion 43 and a third uneven portion 45. The outer side surface 42 is provided with a second uneven portion 44. The inner side surface 41 and the outer side surface 42 are each provided with a non-uneven portion 46. According to this configuration, since the inner side surface 41 and the outer side surface 42 of the magnet accommodating hole 24 each have unevenness, the unevenness can more effectively suppress the vibration of the outer core portion 25. In addition, the non-uneven portion 46 is provided on the inner side surface 41 and the outer side surface 42 of the magnet accommodating hole 24. Therefore, the effect of suppressing leakage magnetic flux by providing the non-uneven portion 46 can be more suitably obtained.

[0037] (3) The first uneven portion 43 and the second uneven portion 44 are provided within the range of a reference circle C1 having a diameter that is half the outer diameter of the rotor core 22. The range indicated by the reference circle C1 is a range toward the radially inner side of the rotor core 22, i.e., a range that is unlikely to contribute to output. For this reason, by providing the first uneven portion 43 within the range of the reference circle C1, it is possible to minimize the reduction in output caused by providing the first uneven portion 43.

[0038] (4) The first uneven portion 43 and the second uneven portion 44 are provided on the folded-back bent portion 24b of the magnet accommodating hole 24. With this configuration, the radially inner end portion of the outer core portion 25 located away from the bridge portion 22c can be axially engaged with the permanent magnet 23 by the first uneven portion 43 and the second uneven portion 44. Therefore, the first uneven portion 43 and the second uneven portion 44 can effectively suppress axial vibration of the outer core portion 25 with the bridge portion 22c as a fulcrum.

[0039] (5) The third uneven portion 45 is provided at the radially outer end 24c of the magnet accommodating hole 24. With this configuration, vibrations in the vicinity of the radially outer end of the outer core portion 25 can be suppressed.

[0040] (6) The convex portion of the third uneven portion 45 is configured by a protruding portion 32c that protrudes inward in the hole width direction of the magnet accommodating hole 24. The protruding portion 32c is formed in the second magnet through hole 32. This allows the circumferential length of the bridge portion 22c corresponding to the second magnet through hole 32 to be shortened. As a result, this contributes to improving the moldability of the core sheet 30.

[0041] (7) The protruding portion 32c is formed at the inner corner of the V-shaped turn-back shape at the radially outer end of the straight portion 32a. This makes it possible to form the third uneven portion 45 by the protruding portion 32c while minimizing the magnetic flux loss of the permanent magnet 23. In addition, by providing the protruding portion 32c, the volume of the permanent magnet 23 can be reduced while minimizing the magnetic flux loss, and therefore the output torque per unit volume of the permanent magnet 23 can be improved.

[0042] (8) The multiple core sheets 30 have the same configuration. In each core sheet 30, the first magnet through holes 31 and the second magnet through holes 32 having different shapes are provided in a mixed manner. The first magnet through holes 31 and the second magnet through holes 32 are mixed in the configuration of one magnet accommodating hole 24. With this configuration, the first magnet through holes 31 and the second magnet through holes 32 overlapping in the axial direction can form the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 in the magnet accommodating hole 24 while facilitating parts management by making each core sheet 30 have the same configuration.

[0043] (9) The core sheets 30 are configured such that the through holes 31 for the first magnets and the through holes 32 for the second magnets are alternately arranged in the circumferential direction. When stacking the core sheets 30 into the rotor core 22, the core sheets 30 are stacked alternately between the first position and the second position rotated by 45° so that the first magnet through holes 31 and the second magnet through holes 32 are mixed in the configuration of one magnet accommodating hole 24. This allows for a simple stacking mode in which each core sheet 30 is placed in either the first position or the second position rotated by one magnet accommodating hole 24 from the first position. In addition, it is possible to minimize magnetic imbalance that may occur when the first magnet through holes 31 and the second magnet through holes 32, which are different in shape, are formed in one core sheet 30.

[0044] (10) The radial hole widths of the bent portions 31b, 32b of the first magnet through hole 31 and the second magnet through hole 32 are made equal. The hole widths of the bent portions 31b, 32b correspond to the thickness of the permanent magnet 23. The first uneven portion 43 and the second uneven portion 44 are formed due to the difference in the radial positions of the bent portions 31b, 32b. With this configuration, it is possible to form the first uneven portion 43 and the second uneven portion 44 on the inner surface of the magnet accommodating hole 24 while ensuring that the magnetic properties of the permanent magnets 23 formed in each magnet accommodating hole 24 are not different from each other.

[0045] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction. In the above embodiment, the protruding portion 32c is formed by tapering the inner corner of the V-shaped folded-back shape at the radially outer end of the straight portion 32a. However, the shape of the protruding portion 32c is not limited to this and may be changed as appropriate to a rectangular shape, a curved shape, or the like.

[0046] In the above embodiment, the protruding portion 32c is provided at the inner corner of the V-shaped turn-back shape at the radially outer end of the straight portion 32a, but this is not limited thereto, and the protruding portion 32c may be provided at the outer corner of the V-shaped turn-back shape at the radially outer end of the straight portion 32a. Also, the protruding portion 32c may be formed in the first magnet through hole 31 instead of the second magnet through hole 32.

[0047] Although each core sheet 30 is arranged so that it alternates between the first position and the second position rotated by 45°, it may be arranged so that multiple sheets are arranged so that it alternates between the first and second positions. In this case, it may be arranged so that the same number of sheets alternate, or it may be arranged so that different numbers alternate. FIG. 6 shows, as an example, a configuration in which every two core sheets 30 are stacked so that they alternate between the first position and the second position rotated by 45°. With such a configuration, it is possible to obtain substantially the same effect as the above embodiment.

[0048] In the above embodiment, the first magnet through holes 31 and the second magnet through holes 32 are alternately arranged in the circumferential direction of the core sheet 30, i.e., the first and second magnet through holes 31, 32 are arranged every other one, but this is not particularly limited. For example, either the first or second magnet through holes 31, 32 may be arranged every third or more.

[0049] For example, as shown in FIG. 7, the number of projections and recesses in the first projection and recess portion 43 may be smaller than the number of projections and recesses in the second projection and recess portion 44. With this configuration, it is possible to form the first projection and recess portion 43 on the inner side surface 41 while ensuring a large length of the inner side surface 41 in the extension direction of the magnet accommodating hole 24, and thus a large surface area of ​​the inner side surface 41. In addition, by ensuring a large surface area of ​​the inner side surface 41, it is possible to contribute to improving the output. In addition, between the first projection and recess portion 43 and the second projection and recess portion 44, the leakage magnetic flux at the first projection and recess portion 43 provided on the inner side surface 41 is more likely to affect the output. Therefore, by configuring the number of projections and recesses in the first projection and recess portion 43 to be smaller than the number of projections and recesses in the second projection and recess portion 44, it is possible to achieve a configuration suitable for suppressing a decrease in output due to leakage magnetic flux at the first projection and recess portion 43.

[0050] In the above embodiment, the depth D1 of the recesses 43a of the first uneven portion 43 is set to be equal to the depth D2 of the recesses 44a of the second uneven portion 44, but this is not particularly limited to this.

[0051] For example, as shown in FIG. 8, the depth D1 of the recess 43a of the first uneven portion 43 may be set to be equal to or less than the depth D2 of the recess 44a of the second uneven portion 44. With this configuration, the length of the inner side surface 41 in the extension direction of the magnet accommodating hole 24, and therefore the surface area of ​​the inner side surface 41, can be secured large, while the second uneven portion 44 of the outer side surface 42 can suitably obtain the axial engagement force with the permanent magnet 23. In addition, between the first uneven portion 43 and the second uneven portion 44, the leakage magnetic flux at the first uneven portion 43 provided on the inner side surface 41 is more likely to affect the output. For this reason, by setting the depth D1 of the recess 43a of the first uneven portion 43 to be equal to or less than the depth D2 of the recess 44a of the second uneven portion 44, a configuration suitable for suppressing the output reduction due to the leakage magnetic flux at the first uneven portion 43 is obtained.

[0052] 9, the depth D2 of the recess 44a of the second uneven portion 44 may be set to be equal to or less than the depth D1 of the recess 43a of the first uneven portion 43. The second uneven portion 44 provided on the outer side surface 42 can ensure a longer length in the extension direction of the magnet accommodating hole 24 as viewed in the axial direction compared to the first uneven portion 43 provided on the inner side surface 41. Therefore, even if the depth D2 of the recess 44a is set small to suppress the output reduction, it is easy to ensure an engagement margin between the second uneven portion 44 and the engagement portion 52. That is, by setting the depth D2 of the recess 44a of the second uneven portion 44 to be equal to or less than the depth D1 of the recess 43a of the first uneven portion 43, it is possible to obtain a suitable engagement force in the axial direction between the inner surface of the magnet accommodating hole 24 and the permanent magnet 23 while suppressing the output reduction.

[0053] In the above embodiment, the radial widths of the bent portions 31b, 32b of the first magnet through hole 31 and the second magnet through hole 32 are set to be equal. The first uneven portion 43 and the second uneven portion 44 are formed by the difference in the radial positions of the bent portions 31b, 32b, but this is not particularly limited and may be changed as appropriate.

[0054] For example, as shown in Fig. 10 and Fig. 11, the first uneven portion 43 and the second uneven portion 44 may be formed by differentiating the hole widths of the bent portions 31b, 32b. In the configuration shown in the figures, the hole width of the bent portion 31b of the first magnet through hole 31 is narrower than the hole width of the bent portion 32b of the second magnet through hole 32. The radial center positions of the bent portions 31b, 32b are set at the same position. With such a configuration, it is possible to obtain substantially the same effect as the above embodiment. It is also possible to combine a configuration in which the positions of the bent portions 31b, 32b are different and a configuration in which the hole widths of the bent portions 31b, 32b are different.

[0055] In the rotor core 22 of the above embodiment and modified example, a connecting portion may be provided that connects the peripheral portions facing each other in the hole width direction at an intermediate position of the folded shape corresponding to the magnet accommodating hole 24. An example of a rotor provided with such a connecting portion is shown in Figures 12 and 13. Note that Figures 12 and 13 show, as an example, a configuration in which a connecting portion is added to the configuration shown in Figures 10 and 11.

[0056] 12, rotor core 22 is provided with a connecting portion 61 that connects between peripheral edge portions facing each other in the hole width direction at a midpoint of the folded shape corresponding to magnet accommodating hole 24. Connecting portion 61 is provided at bent portion 24b of magnet accommodating hole 24, for example.

[0057] In this example, the connecting portion 61 is formed only in the first magnet through hole 31 among the first magnet through hole 31 and the second magnet through hole 32. The connecting portion 61 is formed in the bent portion 31b of each first magnet through hole 31. The connecting portion 61 extends in the hole width direction of the bent portion 31b to connect the peripheral portions facing each other in the same direction. In the connecting portion 61 of each first magnet through hole 31, the width in the direction perpendicular to the extending direction of the connecting portion 61 is set to be, for example, equal to each other. In addition, when each core sheet 30 is stacked as the rotor core 22, each connecting portion 61 in one magnet accommodating hole 24 is arranged on a straight line along the axial direction.

[0058] In this example, the hole width of the bent portion 31b of the first magnet through hole 31 is smaller than the hole width of the bent portion 32b of the second magnet through hole 32. Therefore, by providing the connecting portion 61 at the bent portion 31b of the first magnet through hole 31, the length of the connecting portion 61 in the hole width direction can be made shorter than when a connecting portion is provided at the bent portion 32b of the second magnet through hole 32.

[0059] Also, in this example, no connecting portion is formed in the second magnet through hole 32. Therefore, in the bent portion 24b of the magnet accommodating hole 24, there are portions where there is no connecting portion on every other core sheet 30. And, the magnetic material constituting the permanent magnet 23 fills in the portions where there is no connecting portion. The connecting portion 61 is provided between the first uneven portion 43 and the second uneven portion 44. In other words, the connecting portion 61 connects the first uneven portion 43 and the second uneven portion 44.

[0060] 12 and 13, the outer core portion 25 is supported at three points, including the two bridge portions 22c that are necessarily provided due to the configuration of the magnet accommodating hole 24, and the newly added connecting portion 61 located at the bent portion 24b. This improves the centrifugal force strength of the outer core portion 25. In addition, the three support points consisting of the two bridge portions 22c and the connecting portion 61 are arranged in a balanced manner around the outer core portion 25. This contributes to stable support of the outer core portion 25.

[0061] Furthermore, the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 formed on the inner surface of the magnet accommodating hole 24 suppress axial vibration of the outer core portion 25. Therefore, the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 can suppress deformation of the connecting portion 61 caused by axial vibration of the outer core portion 25 due to application of an axial excitation force to the rotor 20. In other words, the configuration of this example can contribute to improving both the centrifugal strength and the axial strength of the outer core portion 25.

[0062] In this example, each core sheet 30 is disposed at the first or second position. As a result, the connecting portions 61 of the first magnet through holes 31 are located at every other core sheet 30 and do not overlap, so that magnetic flux leakage at the connecting portions 61 can be reduced as much as possible.

[0063] The above-described connecting portion 61 may be formed in the first magnet through hole 31 in the above embodiment. 12 and 13, the connecting portion 61 is formed in the first magnet through hole 31, but the connecting portion 61 may be formed in the second magnet through hole 32. The connecting portion 61 may be formed in both the first magnet through hole 31 and the second magnet through hole 32. In this case, the connecting portion 61 is configured to be continuous over the entire axial direction of the magnet accommodating hole 24. That is, the permanent magnet 23, which is V-shaped when viewed in the axial direction, is configured to be divided by the connecting portion 61. In this case, the permanent magnet 23 has a V-shape as a whole by one portion and the other portion divided by the connecting portion 61, that is, a folded shape that is convex radially inward.

[0064] 12 and 13, the first magnet through hole 31 has one connecting portion 61, but two or more may be provided. In this case, the outer core portion 25 has a total of four or more support points in addition to the two bridge portions 22c that are necessarily provided due to the configuration of the magnet accommodating hole 24.

[0065] In the above example, the connecting portion 61 is provided at the bent portion 24b of the magnet accommodating hole 24, but the connecting portion 61 may be provided at a portion other than the bent portion 24b, such as the straight portion 24a. In addition, in the above example, the direction in which the connecting portion 61 extends is the hole width direction of the bent portion 24b of the magnet accommodating hole 24, and the radial direction of the rotor 20, but the direction may be changed as appropriate, for example, to a direction oblique to the hole width direction or a direction extending other than radially.

[0066] In the above embodiment, the number of the first magnet through holes 31 and the second magnet through holes 32 in one core sheet 30 is the same, but this is not particularly limited. That is, the number of the first magnet through holes 31 in one core sheet 30 may be greater or less than the number of the second magnet through holes 32. Regardless of the number of the first magnet through holes 31 and the second magnet through holes 32, the shapes of the first magnet through holes 31 and the second magnet through holes 32 are configured to be point symmetric about the axis L, thereby making it possible to suppress magnetic imbalance in the circumferential direction.

[0067] For example, in the above embodiment, when the number of the first magnet through holes 31 is changed to two and the number of the second magnet through holes 32 is changed to four, the two first magnet through holes 31 are arranged at 180° opposing positions, so that it is possible to suppress magnetic imbalance in the circumferential direction. In the example shown in Figs. 10 to 13, the hole width of the bent portion 31b of the first magnet through hole 31 is narrower than the hole width of the bent portion 32b of the second magnet through hole 32. That is, the thickness of the bent portion 23b of the permanent magnet 23 is thinner in the first magnet through hole 31 than in the second magnet through hole 32. Therefore, by configuring the number of the first magnet through holes 31 to be smaller than the number of the second magnet through holes 32, it is possible to suppress the decrease in output torque. In addition, in the above embodiment, during the process of stacking the core sheets 30, each core sheet 30 is rotated by 45°, which is one magnetic pole, but the rotation angle during stacking is not limited to 45°, which is one magnetic pole, and may be an angle other than 45°, such as two or three magnetic poles.

[0068] The position where the uneven portion is formed on the inner surface of the magnet accommodating hole 24 is not limited to that in the above embodiment and can be changed as appropriate. For example, the uneven portion may be formed on the inner surface of the magnet accommodating hole 24 in the middle of the straight portion 24a when viewed in the axial direction. Also, in the magnet accommodating hole 24 of the above embodiment, for example, any one of the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 may be omitted.

[0069] In the above embodiment, the first uneven portion 43, the second uneven portion 44, and the third uneven portion 45 are formed partially in the extension direction of the magnet accommodating hole 24, and the non-uneven portion 46 is formed at other locations in the extension direction of the magnet accommodating hole 24, but this is not particularly limited. For example, an uneven portion may be formed on the inner surface of the magnet accommodating hole 24 in a part of the axial direction, and a non-uneven portion may be formed at locations in the axial direction other than the uneven portion.

[0070] In the above embodiment, the core sheet 30 is formed with two types of magnet through holes having different shapes, i.e., the first and second magnet through holes 31 and 32, but is not particularly limited thereto. For example, a first core sheet and a second core sheet having magnet through holes having different shapes are prepared as core sheets constituting the rotor core 22. In the first core sheet, only the first magnet through holes 31 are formed in a plurality of positions in the circumferential direction as magnet through holes. In the second core sheet, only the second magnet through holes 32 are formed in a plurality of positions in the circumferential direction as magnet through holes. Then, the first core sheet and the second core sheet may be alternately stacked one by one to form a magnet accommodating hole 24 in which the first magnet through holes 31 and the second magnet through holes 32 are mixed in the axial direction.

[0071] The number of magnetic poles of the rotor 20, i.e., the number of permanent magnets 23 and magnet accommodating holes 24, may be changed as appropriate. Also, the number of magnetic poles of the stator 10 may be changed as appropriate. Other than the above, the configuration of the rotating electric machine M may be changed as appropriate.

[0072] The embodiments and modified examples disclosed herein are illustrative in all respects, and the present invention is not limited to these examples. That is, the scope of the present invention is defined by the claims, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

[0073] The technical concept is described below. [1] A rotor (20) including a rotor core (22) having a plurality of magnet accommodating holes (24) each having a convex folded shape on the radially inward side, and a permanent magnet (23) embedded in the magnet accommodating holes, wherein the rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, each of the plurality of core sheets has a magnet through hole (31, 32), the magnet accommodating holes are formed by the magnet through holes of the plurality of core sheets overlapping in the axial direction, the inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by differences in the positions of the peripheral portions of the magnet through holes that overlap in the axial direction, and a non-uneven portion (46) which is a portion where the uneven portions are not formed, and the permanent magnets have engagement portions (51, 52, 53) that fit into the concave portions (43a, 44a, 45a) of the uneven portions.

[0074] [2] The rotor core has an outer core portion (25) that is radially outer than the permanent magnet, and the inner surface of the magnet accommodating hole includes an inner side surface (41) that forms the outer core portion and an outer side surface (42) that faces the inner side surface, and the uneven portion is provided on each of the inner side surface and the outer side surface, and the non-uneven portion is provided on each of the inner side surface and the outer side surface. The rotor described in [1] above.

[0075] [3] The rotor described in [2] above, wherein a depth (D1) of the recess provided on the inner side surface is set to be equal to or less than a depth (D2) of the recess provided on the outer side surface. [4] The rotor described in [2] above, wherein the depth (D2) of the recess provided on the outer side surface is set to be equal to or less than the depth (D1) of the recess provided on the inner side surface.

[0076] [5] A rotor described in any one of [2] to [4] above, wherein the number of projections and recesses in the projection-recess portion provided on the inner side surface is less than the number of projections and recesses in the projection-recess portion provided on the outer side surface.

[0077] [6] A rotor described in any one of [1] to [5] above, wherein the uneven portion is provided radially inwardly of half the outer diameter of the rotor core. [7] The rotor according to any one of the above [1] to [6], wherein the uneven portion is provided at a radially outer end (24c) of the magnet accommodating hole.

[0078] [8] A rotor described in any one of [1] to [7] above, wherein the multiple core sheets have the same configuration, the magnet through holes have different shapes and include a first magnet through hole (31) and a second magnet through hole (32) that are mixed in one of the core sheets, and the first magnet through hole and the second magnet through hole are mixed in the configuration of one of the magnet accommodating holes.

[0079] [9] The rotor described in [8] above, wherein the core sheet is configured such that the first magnet through holes and the second magnet through holes are arranged alternately in the circumferential direction.

[10] The rotor core is configured such that a predetermined number of the core sheets are arranged in either a first position or a second position rotated by one magnet accommodating hole from the first position.

[10] The rotor core is configured as described in [9] above.

[0080]

[11] The rotor according to any one of the above [1] to

[10] , wherein the uneven portion is provided on a folded-back bent portion (24b) of the magnet accommodating hole.

[12] A rotor as described in any one of [1] to

[11] above, wherein the rotor core has a connecting portion (61) that connects between opposing peripheral portions in the hole width direction at an intermediate position of the folded shape corresponding to the magnet accommodating hole.

[0081]

[13] The rotor according to the above

[12] , wherein the connecting portion is provided at a folded-back bent portion (24b) of the magnet accommodating hole.

[14] A rotating electric machine (M) including a rotor (20) including a rotor core (22) having a plurality of magnet accommodating holes (24) each having a convex folded shape on the radially inward side, and permanent magnets (23) embedded in the magnet accommodating holes, and a stator (10) that applies a rotating magnetic field to the rotor, wherein the rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, each of the plurality of core sheets having magnet through holes (31, 32), a rotating electric machine in which the magnet accommodating hole is formed by the magnet through holes of the multiple core sheets overlapping in the axial direction, and the inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by the difference in position of the peripheral portions of the magnet through holes overlapping in the axial direction, and a non-uneven portion (46) which is a portion where the uneven portions are not formed, and the permanent magnet has engagement portions (51, 52, 53) which fit into the recesses (43a, 44a, 45a) of the uneven portions.

[0082] According to the rotor of [1] and the rotating electric machine of

[14] , the uneven portion of the magnet accommodating hole axially engages with the engaging portion of the permanent magnet, thereby making it possible to suppress axial vibration of the outer core portion, which is the portion of the rotor core radially outward of the permanent magnet. As a result, it is possible to suppress deformation of the rotor core. Therefore, it is possible to improve the strength of the rotor core against axial vibration. In addition, a non-uneven portion is provided on the inner surface of the magnet accommodating hole. As a result, compared to a configuration in which the entire inner surface of the magnet accommodating hole has uneven portions, it is possible to suppress axial leakage magnetic flux generated by the unevenness of the boundary between the magnet accommodating hole and the permanent magnet. [Explanation of symbols]

[0083] M rotating electric machine, 10 stator, 20 rotor, 22 rotor core, 23 permanent magnet, 23b bent portion, 24 magnet accommodating hole, 24b bent portion, 24c radial outer end portion, 25 outer core portion, 30 core sheet, 31 first magnet through hole (magnet through hole), 31b bent portion, 32 second magnet through hole (magnet through hole), 32b bent portion, 41 inner side surface, 42 outer side surface, 43 first uneven portion (uneven portion), 43a recess, 44 second uneven portion (uneven portion), 44a recess, 45 third uneven portion (uneven portion), 45a recess, 46 non-uneven portion, 51 to 53 engaging portions, 61 connecting portions, D1, D2 depth.

Claims

1. A rotor (20) comprising: a rotor core (22) having a plurality of magnet accommodating holes (24) each having a convex folded shape on the radially inward side; and permanent magnets (23) embedded in the magnet accommodating holes, The rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, Each of the plurality of core sheets has a through hole (31, 32) for a magnet, The magnet through holes of the plurality of core sheets are overlapped in the axial direction to form the magnet accommodating hole, The inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by differences in the positions of the peripheral portions of the magnet through holes that overlap in the axial direction, The permanent magnet has engagement portions (51, 52, 53) that fit into the recesses (43a, 44a, 45a) of the uneven portions. Rotor.

2. The rotor core has an outer core portion (25) that is a portion radially outward of the permanent magnet, The inner surface of the magnet accommodating hole includes an inner side surface (41) forming the outer core portion and an outer side surface (42) facing the inner side surface, The uneven portion is provided on each of the inner side surface and the outer side surface. The rotor of claim 1 .

3. The depth (D1) of the recess provided on the inner side surface is set to be equal to or less than the depth (D2) of the recess provided on the outer side surface. A rotor according to claim 2.

4. The depth (D2) of the recess provided on the outer side surface is set to be equal to or less than the depth (D1) of the recess provided on the inner side surface. A rotor according to claim 2.

5. The number of projections and recesses in the projection-recess portion provided on the inner side surface is smaller than the number of projections and recesses in the projection-recess portion provided on the outer side surface. A rotor according to any one of claims 2 to 4.

6. The uneven portion is provided radially inwardly of half the outer diameter of the rotor core. A rotor according to any one of claims 1 to 5.

7. The uneven portion is provided at a radially outer end portion (24c) of the magnet accommodating hole. A rotor according to any one of claims 1 to 6.

8. The plurality of core sheets have the same configuration, The magnet through holes include a first magnet through hole (31) and a second magnet through hole (32) having different shapes and arranged in a mixed manner in one of the core sheets, The first magnet through hole and the second magnet through hole are mixed in one configuration of the magnet accommodating hole. A rotor according to any one of claims 1 to 7.

9. The core sheet is configured such that the first magnet through holes and the second magnet through holes are alternately arranged in a circumferential direction. A rotor as claimed in claim 8.

10. The rotor core is configured such that a predetermined number of the core sheets are arranged in either a first position or a second position rotated by one magnet accommodating hole from the first position. A rotor as claimed in claim 9.

11. The uneven portion is provided on a folded-back bent portion (24b) of the magnet accommodating hole. A rotor according to any one of claims 1 to 10.

12. The rotor core has a connecting portion (61) that connects between peripheral edge portions facing each other in a hole width direction at a midpoint of the folded shape corresponding to the magnet accommodating hole. A rotor according to any one of claims 1 to 11.

13. The connecting portion is provided at a folded-back bent portion (24b) of the magnet accommodating hole. A rotor as claimed in claim 12.

14. A rotor (20) including a rotor core (22) having a plurality of magnet accommodating holes (24) each having a convex folded shape on the radially inward side, and a permanent magnet (23) embedded in the magnet accommodating hole; A stator (10) that applies a rotating magnetic field to the rotor; A rotating electric machine (M) comprising: The rotor core is formed by stacking a plurality of core sheets (30) in the axial direction, Each of the plurality of core sheets has a through hole (31, 32) for a magnet, The magnet through holes of the plurality of core sheets are overlapped in the axial direction to form the magnet accommodating hole, The inner surface of the magnet accommodating hole is provided with uneven portions (43, 44, 45) formed by differences in the positions of the peripheral portions of the magnet through holes that overlap in the axial direction, The permanent magnet has engagement portions (51, 52, 53) that fit into the recesses (43a, 44a, 45a) of the uneven portions. Rotating electric motor.

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