Rotating electric machines

Abstract

A rotating electrical machine includes a stator and a rotor rotatably arranged relative to the stator, the rotor having a rotor core formed with a plurality of holes arranged in a circumferential direction of the rotor and at least one permanent magnet, the number of magnetic poles of the rotor being an even number p greater than 2, the plurality of holes including p / 2 first holes into which the permanent magnets are inserted and p / 2 second holes into which the permanent magnets are not inserted, the first holes and the second holes being arranged alternately in a circumferential direction, the permanent magnets being magnetized in such a manner that magnetic pole surfaces facing each other in a circumferential direction with the second hole sandwiched therebetween become different poles, and the second hole having a first opening portion opening toward the stator side in a radial direction of the rotor.

Description

Technical Field

[0001] The present invention relates to a rotating electrical machine having an embedded magnet rotor. Background Art

[0002] Patent document 1 describes an embedded magnet motor. In the embedded magnet motor, rectangular slits of 1 / 2 the number of motor poles P and rectangular permanent magnets of the same number as the slits are alternately arranged at predetermined intervals in the circumferential direction on the annular surface of the rotor. P segmented regions are formed between each slit and the permanent magnet. The segmented regions are alternately magnetized into N poles and S poles along the circumferential direction.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-200480 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the rotor of the embedded magnet type motor, two adjacent segmented areas separated by a slit are connected to each other via a connecting portion located on the inner circumference side of the slit and a connecting portion located on the outer circumference side of the slit. Therefore, a closed magnetic circuit is formed in the rotor in which magnetic flux flows in the circumferential direction through these connecting portions. Therefore, there is a problem that the circumferential leakage magnetic flux that does not interlink with the stator increases, so the torque output of the motor decreases.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a rotating electric machine capable of improving torque output.

[0009] Solutions to Solve Problems

[0010] The rotating electric machine of the present invention comprises: a stator; and a rotor rotatably arranged relative to the stator, the rotor having: a rotor core formed with a plurality of holes arranged in the circumferential direction of the rotor; and at least one permanent magnet, the number of magnetic poles of the rotor being p which is an even number greater than 2, the plurality of holes including p / 2 first holes into which the permanent magnets are inserted and p / 2 second holes into which the permanent magnets are not inserted, the first holes and the second holes being arranged alternately in the circumferential direction, the permanent magnets being magnetized in such a manner that magnetic pole surfaces facing each other in the circumferential direction with the second hole sandwiched therebetween become different poles, and the second hole having a first opening portion opening toward the stator side in the radial direction of the rotor.

[0011] Effects of the Invention

[0012] According to the present invention, the torque output of the rotating electric machine can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a cross-sectional view showing the structure of the rotating electrical machine according to the first embodiment of the present invention cut perpendicularly to the axial direction.

[0014] Figure 2 This is a cross-sectional view showing a structure of a rotating electrical machine according to a comparative example of the first embodiment of the present invention, cut perpendicularly to the axial direction.

[0015] Figure 3 Yes Figure 2 A diagram showing an enlarged portion of a portion.

[0016] Figure 4 Yes Figure 1 A diagram showing an enlarged portion of a portion.

[0017] Figure 5 This is a graph showing the torque obtained by the rotating electric machine according to the first embodiment of the present invention and the torque obtained by the rotating electric machine according to the comparative example.

[0018] Figure 6 This is a graph showing the relationship between the magnitude relationship between the opening width Lo1 and the gap Gm and the torque in the rotating electrical machine according to the first embodiment of the present invention.

[0019] Figure 7 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to Modification 1-1 of Embodiment 1 of the present invention, cut perpendicularly to the axial direction.

[0020] Figure 8 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to Modification 1-2 of Embodiment 1 of the present invention, cut perpendicularly to the axial direction.

[0021] Fig. 9 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to Modification 1-3 of Embodiment 1 of the present invention, cut perpendicularly to the axial direction.

[0022] Fig.10 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to Modification 1-4 of Embodiment 1 of the present invention, cut perpendicularly to the axial direction.

[0023] Fig.11 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to a second embodiment of the present invention cut perpendicularly to the axial direction.

[0024] Fig.12 This is a graph showing the relationship between the magnitude relationship between the width L1 and the width L2 and the torque in the rotary electric machine according to the second embodiment of the present invention.

[0025] Fig.13This is a cross-sectional view showing a structure in which a rotor of a rotating electrical machine according to a modification 2-1 of the second embodiment of the present invention is cut perpendicularly to the axial direction.

[0026] Fig.14 This is a cross-sectional view showing a structure in which a rotor of a rotating electrical machine according to a modification 2-2 of the second embodiment of the present invention is cut perpendicularly to the axial direction.

[0027] Fig.15 This is a cross-sectional view showing a structure in which a rotor of a rotating electrical machine according to a modification 2-3 of the second embodiment of the present invention is cut perpendicularly to the axial direction.

[0028] Fig.16 This is a cross-sectional view showing a structure in which a rotor of a rotating electrical machine according to a modification 2-4 of the second embodiment of the present invention is cut perpendicularly to the axial direction.

[0029] Fig.17 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to a third embodiment of the present invention cut perpendicularly to the axial direction.

[0030] Fig.18 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to a modification 3-1 of the third embodiment of the present invention, cut perpendicularly to the axial direction.

[0031] Fig.19 It is an exploded perspective view showing the structure of a rotor of a rotating electrical machine according to Modification 3-2 of Embodiment 3 of the present invention.

[0032] Fig. 20 This is a cross-sectional view showing a structure of a third rotor core of a rotating electrical machine according to a modification 3-2 of the third embodiment of the present invention, cut perpendicularly to the axial direction.

[0033] Fig.21 It is an exploded perspective view showing the structure of a rotor of a rotating electrical machine according to Modification 3-3 of Embodiment 3 of the present invention.

[0034] Fig. 22 This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to a fourth embodiment of the present invention cut perpendicularly to the axial direction.

[0035] Fig.23 This is a cross-sectional view showing a structure in which a rotor of a rotating electrical machine according to a modification 4-1 of the fourth embodiment of the present invention is cut perpendicularly to the axial direction.

[0036] Fig.24 It is a cross-sectional view showing a structure obtained by cutting the rotor of a rotating electrical machine according to Modification 4-2 of Embodiment 4 of the present invention perpendicularly to the axial direction.

[0037] Fig.25This is a cross-sectional view showing a structure of a rotor of a rotating electrical machine according to a fifth embodiment of the present invention cut perpendicularly to the axial direction. DETAILED DESCRIPTION

[0038] Implementation method 1.

[0039] A rotating electrical machine according to Embodiment 1 of the present invention will be described. Figure 1 1 is a cross-sectional view showing a structure of the rotary electric machine 100 of the present embodiment cut perpendicularly to the axial direction. Here, the direction along the axis of the rotor 20 is referred to as the axial direction, the direction along the radius of the rotor 20 in the cross section perpendicular to the axial direction is referred to as the radial direction, and the direction along the rotation direction of the rotor 20 in the cross section is referred to as the circumferential direction.

[0040] like Figure 1 As shown, the rotating electric machine 100 has a stator 10 and a rotor 20 rotatably arranged relative to the stator 10. The stator 10 is arranged so as to surround the outer circumference of the rotor 20 via a gap 15 serving as a magnetic gap. The stator 10 has a stator core 11. The stator core 11 has a core back 12 formed in an annular shape and a plurality of teeth 13 protruding from the core back 12 toward the inner circumference. In addition, the stator 10 has a plurality of windings 14 respectively wound around the plurality of teeth 13 in a concentrated winding manner. Figure 1 In the structure shown, 12 teeth 13 and 12 windings 14 are provided. Figure 2 As shown, the core back 12 may also be formed by a plurality of arc-shaped core blocks.

[0041] The rotor 20 has a rotor core 21 and permanent magnets 22 disposed inside the rotor core 21. The rotor 20 is a longitudinally embedded magnet type rotor in which the permanent magnets 22 are radially arranged inside the rotor core 21. The longitudinally embedded magnet type rotor is sometimes also called a spoke type rotor. In addition, the rotor 20 is a commutation pole type rotor having p / 2 permanent magnets 22 when the number of magnetic poles is set to p. Here, p is an even number greater than 2. Figure 1 In the illustrated structure, the number p of magnetic poles of the rotor 20 is 10, and therefore the number of permanent magnets 22 is five.

[0042] The rotor core 21 has a structure in which a plurality of core plates are stacked in the axial direction. The rotor core 21 is formed with a plurality of holes 30 that penetrate in the axial direction. The plurality of holes 30 are arranged along the circumferential direction of the rotor 20. In a cross section perpendicular to the axial direction, the plurality of holes 30 each have a rectangular shape. In the cross section, the plurality of holes 30 are radially arranged in a manner that the length direction is along the radial direction. The number of holes 30 is p, which is equal to the number of magnetic poles of the rotor 20.

[0043] Permanent magnets 22 are inserted into some of the holes in the plurality of holes 30. That is, the plurality of holes 30 include a plurality of first holes 31 in which the permanent magnets 22 are inserted and a plurality of second holes 32 in which the permanent magnets 22 are not inserted. The number of the first holes 31 and the number of the second holes 32 are both p / 2. The plurality of first holes 31 and the plurality of second holes 32 are arranged alternately in the circumferential direction of the rotor 20. The interior of the second hole 32 may also be a space. Alternatively, a non-magnetic component formed of a non-magnetic material such as a resin or a non-magnetic metal may be inserted into the interior of the second hole 32. In addition, the rotor core 21 may also be held by a non-magnetic component inserted into the second hole 32.

[0044] The plurality of permanent magnets 22 are magnetized so that two magnetic pole faces adjacent to each other in the circumferential direction with the second hole 32 interposed therebetween have different poles. Figure 1 The magnetic pole facing counterclockwise is the N pole. Figure 1 The magnetic pole surface facing clockwise is the S pole.

[0045] The second hole 32 has a first opening portion 33 that opens radially toward the stator 10 side. In the present embodiment, the first opening portion 33 opens radially toward the outside. The first opening portion 33 forms a circumferential magnetic gap at the outer periphery of the rotor core 21. The first opening portion 33 may also be a space. Alternatively, the first opening portion 33 may be filled with a non-magnetic component.

[0046] In addition, the second hole 32 has a second opening portion 34 that opens radially toward the side opposite to the stator 10. In the present embodiment, the second opening portion 34 opens radially inward. The second opening portion 34 forms a circumferential magnetic gap at the inner circumference of the rotor core 21. The second opening portion 34 may also be a space. Alternatively, the second opening portion 34 may be filled with a non-magnetic component.

[0047] Figure 2 2 is a cross-sectional view showing a structure of a rotary electric machine 200 according to a comparative example of the present embodiment cut perpendicularly to the axial direction. Figure 2 As shown, the rotary electric machine 200 of this comparative example is different from the rotary electric machine 200 in that the first opening 33 and the second opening 34 are not formed. Figure 1 That is, in the rotary electric machine 200 of this comparative example, the radial outer side of the second hole 32 is closed by the connecting portion 201, and the radial inner side of the second hole 32 is closed by the connecting portion 202. It should be noted that the core back 12 of this comparative example is formed by a plurality of arc-shaped core blocks, but the core back 12 may also be formed as Figure 1 As shown, it is formed into an integral circular ring shape.

[0048] Figure 3 Yes Figure 2 A diagram showing a portion of the image enlarged. Figure 3In FIG. 1 , the solid arrows represent the effective magnetic flux Φ1 that interlinks with the stator 10 and contributes to the torque, and the dotted arrows represent the circumferential leakage magnetic flux Φ2 that passes through the circumferential closed magnetic circuit in the rotor core 21. Figure 3 As shown, the radial outer side and the radial inner side of the second hole 32 are closed by the connecting portion 201 and the connecting portion 202, respectively. The magnetic resistance of the connecting portion 201 and the connecting portion 202 is very low compared to the magnetic resistance of the gap 15. Therefore, it is difficult to form a magnetic circuit that causes the magnetic flux to interlink with the stator 10 by actively forming a circumferential closed magnetic circuit in the rotor core 21. As a result, the circumferential leakage magnetic flux Φ2 passing through the connecting portion 201 and the connecting portion 202 becomes relatively large relative to the amount of permanent magnets 22 used, and therefore, the effective magnetic flux Φ1 interlinked with the stator 10 through the gap 15 becomes small. Therefore, in a structure such as this comparative example, it is difficult to increase the torque output of the rotating electric machine 200.

[0049] In contrast, in the present embodiment, the first opening 33 and the second opening 34 are formed on the radially outer side and the radially inner side of the second hole 32 , respectively. Figure 4 Yes Figure 1 A diagram showing a portion of the image enlarged. Figure 4 In, with Figure 3 Similarly, the solid arrows represent the effective magnetic flux Φ1, and the dotted arrows represent the circumferential leakage magnetic flux Φ2. Figure 4 As shown, the circumferential closed magnetic circuit closed in the rotor core 21 necessarily passes through the second hole 32, the first opening 33 or the second opening 34, so the magnetic resistance of the closed magnetic circuit becomes higher. As a result, the circumferential leakage magnetic flux Φ2 can be reduced, especially near the outer periphery of the rotor core 21, and the effective magnetic flux Φ1 interlinked with the stator 10 can be increased. Therefore, in the rotary electric machine 100 of this embodiment, the torque output can be improved compared with the rotary electric machine 200 of the comparative example.

[0050] Figure 5 : is a graph showing the torque obtained by the rotary electric machine 100 of the present embodiment and the torque obtained by the rotary electric machine 200 of the comparative example. The vertical axis of the graph represents the torque [pu] obtained by normalizing the torque of the rotary electric machine 100 of the present embodiment to 1. Figure 5 As shown, when the torque obtained by the rotating electric machine 100 of the present embodiment is set to 1, the torque obtained by the rotating electric machine 200 of the comparative example is approximately 0.91. Therefore, it can be seen that the rotating electric machine 100 of the present embodiment can obtain a higher torque than the rotating electric machine 200 of the comparative example.

[0051] Next, the opening width of the first opening 33 will be described. Here, the first opening 33 refers to the opening of the second hole 32 that opens toward the stator 10 in the radial direction. In the present embodiment, the stator 10 is disposed on the outer peripheral side of the rotor 20, so the first opening 33 opens toward the radial outer side. Figure 4 As shown, the opening width of the first opening 33 in the tangential direction along the circumferential direction of the rotor 20 is Lo1. In addition, the interval between the rotor 20 and the stator 10 in the radial direction is Gm. The interval Gm is the radial width of the gap 15 that becomes the magnetic gap between the rotor 20 and the stator 10.

[0052] Figure 6 : is a graph showing the relationship between the magnitude relationship of the opening width Lo1 and the interval Gm and the torque in the rotary electric machine 100 of the present embodiment. The vertical axis of the graph represents the torque [pu] normalized to 1 when the opening width Lo1 and the interval Gm are equal. Figure 6 As shown, if the torque when the opening width Lo1 is equal to the interval Gm (Lo1=Gm) is set to 1, the torque when the opening width Lo1 is larger than the interval Gm (Lo1>Gm) is approximately 1.58. Therefore, it can be seen that when the opening width Lo1 is larger than the interval Gm, a higher torque can be obtained than when the opening width Lo1 is equal to the interval Gm. This is because the magnetic flux coming out of the permanent magnet 22 passes through a path with a smaller magnetic resistance. When the opening width Lo1 is larger than the interval Gm, the magnetic resistance of the path through the first opening portion 33 tends to become larger than the magnetic resistance of the path through the gap 15. Therefore, more of the magnetic flux coming out of the permanent magnet 22 becomes the effective magnetic flux Φ1 that interlinks with the stator 10.

[0053] Figure 7 2 is a cross-sectional view showing a structure of a rotor 20 of a rotary electric machine 100 according to a modification 1-1 of the present embodiment cut perpendicularly to the axial direction. Figure 7 Although the stator 10 is not shown in the drawings and the following drawings, the stator 10 is provided on the outer peripheral side of the rotor 20 . Figure 1 as well as Figure 4 The rotor core 21 shown has a perfect circular shape when viewed perpendicularly to the axial direction. Figure 7 As shown, the rotor core 21 of the rotor 20 of this modification has a non-circular shape when viewed perpendicularly to the axial direction. Figure 7In the figure, a circumscribed circle externally connected to the rotor core 21 is indicated by a dashed line. Let the radius of this circumscribed circle be R0. The outer peripheral surface of the rotor core 21 is formed in an arc shape in the intervals respectively sandwiched by two holes 30 adjacent in the circumferential direction. The centers of curvature of the outer peripheral surfaces 21a of the respective intervals are different from each other, and also different from the center of the circumscribed circle. The radius of curvature R1 of the outer peripheral surfaces 21a of the respective intervals is smaller than the radius R0 of the circumscribed circle (R1 < R0). By forming the shape of the rotor core 21 into Figure 7 the shape shown instead of a perfect circular shape, it is possible to reduce the cogging torque and torque ripple.

[0054] Here, when using Figure 7 the rotor 20 having the non-circular shape shown, the interval Gm between the rotor 20 and the stator 10 varies according to the circumferential position of the rotor 20. In this case, the opening width Lo1 of the first opening 33 is preferably larger than the maximum value Gmmax of the interval Gm (Lo1 > Gmmax).

[0055] Figure 8 is a cross-sectional view showing the structure of the rotor 20 of the rotating electrical machine 100 according to Modification 1-2 of the present embodiment cut perpendicularly to the axial direction. In Figure 1 and Figure 4 the rotor 20 shown, the width of the first hole 31 in the tangential direction along the circumferential direction is the same as the width of the second hole 32 in the tangential direction along the circumferential direction. In contrast, in the rotor 20 of this modification, as Figure 8 shown, the width Lh1 of the first hole 31 in the tangential direction along the circumferential direction is narrower than the width Lh2 of the second hole 32 in the tangential direction along the circumferential direction (Lh1 < Lh2). According to this modification, it is also possible to obtain the same effects as those of the rotor 20 shown in Figure 1 and Figure 4 shown.

[0056] Fig. 9 is a cross-sectional view showing the structure of the rotor 20 of the rotating electrical machine 100 according to Modification 1-3 of the present embodiment cut perpendicularly to the axial direction. As Fig. 9 shown, in the rotor 20 of this modification, the width Lh1 of the first hole 31 in the tangential direction along the circumferential direction is wider than the width Lh2 of the second hole 32 in the tangential direction along the circumferential direction (Lh1 > Lh2). According to this modification, it is also possible to obtain the same effects as those of the rotor 20 shown in Figure 1 and Figure 4 shown.

[0057] Fig.10 is a cross-sectional view showing the structure of the rotor 20 of the rotating electrical machine 100 according to Modification 1-4 of the present embodiment cut perpendicularly to the axial direction. In Figure 1 and Figure 4The second hole 32 of the rotor 20 shown in the figure is formed with a first opening portion 33 opening in the radial direction toward the stator 10 side and a second opening portion 34 opening in the radial direction toward the side opposite to the stator 10. In contrast, in the second hole 32 of the rotor 20 of the present modification, as shown in FIG. Fig.10 As shown in FIG. 1 , only the first opening 33 is formed, and the second opening 34 is not formed. Figure 2 as well as Figure 3 Compared with the structure of the comparative example shown in the figure, the circumferential leakage flux Φ2 of the rotor core 21, especially the part on the radial side of the stator 10, that is, the part on the radial outside, can be reduced. Therefore, according to this modification, the effective magnetic flux Φ1 can also be increased, and the torque output of the rotating electric machine 100 can be improved.

[0058] As described above, the rotary electric machine 100 of the present embodiment includes the stator 10 and the rotor 20 rotatably arranged relative to the stator 10. The rotor 20 has a rotor core 21 formed with a plurality of holes 30 arranged in the circumferential direction of the rotor 20 and at least one permanent magnet 22. The number of magnetic poles of the rotor 20 is an even number p greater than 2. The plurality of holes 30 include p / 2 first holes 31 into which the permanent magnets 22 are inserted and p / 2 second holes 32 into which the permanent magnets 22 are not inserted. The first holes 31 and the second holes 32 are arranged alternately in the circumferential direction. The permanent magnets 22 are magnetized in such a manner that the magnetic pole faces facing each other in the circumferential direction with the second holes 32 sandwiched therebetween become different poles. The second hole 32 has a first opening portion 33 that opens toward the stator 10 side in the radial direction of the rotor 20.

[0059] According to this structure, the magnetic resistance in the circumferential closed magnetic circuit can be increased in at least the portion of the rotor core 21 that is on the stator 10 side in the radial direction. As a result, the circumferential leakage flux Φ2 can be reduced in the portion of the rotor core 21 that is on the stator 10 side in the radial direction, and the effective magnetic flux Φ1 interlinked with the stator 10 can be increased. Therefore, the torque output of the rotating electrical machine 100 can be improved. In addition, according to the above structure, since the p-pole rotor 20 is formed using p / 2 permanent magnets 22, the amount of permanent magnets 22 used can be reduced.

[0060] In the rotary electric machine 100 of the present embodiment, the second hole 32 has a second opening 34 that opens radially to the side opposite to the stator 10. According to this structure, the magnetic resistance in the circumferential closed magnetic circuit can be increased in the portion of the rotor core 21 on the side opposite to the stator 10 in the radial direction. As a result, the circumferential leakage magnetic flux Φ2 can also be reduced in the portion of the rotor core 21 on the side opposite to the stator 10 in the radial direction, and thus the effective magnetic flux Φ1 interlinked with the stator 10 can be further increased.

[0061] In the rotary electric machine 100 of the present embodiment, when the opening width of the first opening 33 is set to Lo1 and the maximum value of the interval between the stator 10 and the rotor 20 in the radial direction is set to Gmmax, the relationship of Lo1>Gmmax is satisfied. According to this structure, the magnetic resistance of the path through the first opening 33 is likely to be larger than the magnetic resistance of the path through the gap 15, so that the effective magnetic flux Φ1 interlinked with the stator 10 can be further increased.

[0062] Implementation method 2.

[0063] A rotating electrical machine according to a second embodiment of the present invention will be described. Fig.11 It is a cross-sectional view showing the structure of the rotor 20 of the rotary electric machine 100 according to the present embodiment cut perpendicularly to the axial direction. Components having the same functions and effects as those of the first embodiment are denoted by the same reference numerals and their description is omitted.

[0064] like Fig.11 As shown, the second hole 32 has a first portion 32a and a second portion 32b located closer to the stator 10 than the first portion 32a in the radial direction. Fig.11 When the width of the first portion 32a in the tangential direction along the circumferential direction is L1 and the width of the second portion 32b in the tangential direction is L2, the relationship L1>L2 is satisfied.

[0065] If used Figure 1 as well as Figure 4 As described above, in the first embodiment, the torque output of the rotating electrical machine 100 can be improved. However, since it is difficult to make the circumferential leakage flux Φ2 zero, Figure 4 As shown by the dashed arrow in , there is also a circumferential leakage flux Φ2 in Embodiment 1. In order to further improve the torque output of the rotating electrical machine 100, it is necessary to further reduce the circumferential leakage flux Φ2. Figure 1 as well as Figure 4 In the rotor 20 of the first embodiment shown, it is considered that the circumferential leakage flux Φ2 is large on the inner circumference side far from the stator 10, and the circumferential leakage flux Φ2 is small on the outer circumference side close to the stator 10. Therefore, the inventors of the present application believe that if the width L1 of the first portion 32a of the second hole 32 is made wider than the width L2 of the second portion 32b located on the outer circumference side of the first portion 32a, the circumferential leakage flux Φ2 on the inner circumference side can be reduced, and therefore the effective magnetic flux Φ1 can be increased.

[0066] Fig.12: is a graph showing the relationship between the magnitude relationship of the width L1 and the width L2 and the torque in the rotary electric machine 100 of the present embodiment. The vertical axis of the graph represents the torque [pu] normalized to 1 when the torque is L1=L2. Fig.12 As shown, if the torque obtained when L1=L2 is set to 1, the torque obtained when L1>L2 is approximately 1.036. Therefore, it can be seen that the torque output of the rotating electrical machine 100 can be further improved by making the width L1 of the first portion 32a wider than the width L2 of the second portion 32b.

[0067] exist Fig.11 In the illustrated structure, the width of the second hole 32 changes in two stages, but other structures are also conceivable. Fig.13 2 is a cross-sectional view showing a structure of a rotor 20 of a rotary electric machine 100 according to a modification 2-1 of the present embodiment cut perpendicularly to the axial direction. Fig.13 In the structure shown, the second hole 32 has a first portion 32a, a second portion 32b located radially outward of the first portion 32a, and a third portion 32c located radially outward of the second portion 32b. When the width of the first portion 32a in the tangential direction along the circumferential direction is L1, the width of the second portion 32b in the tangential direction is L2, and the width of the third portion 32c in the tangential direction is L3, the relationship of L1>L2>L3 is satisfied. In this way, the width of the second hole 32 may also be changed in three or more stages.

[0068] Fig.14 2 is a cross-sectional view showing a structure of a rotor 20 of a rotary electric machine 100 according to a modification 2-2 of the present embodiment cut perpendicularly to the axial direction. Fig.14 In the illustrated structure, the width of the second hole 32 increases monotonically as it moves away from the stator 10 in the radial direction. The second hole 32 is sandwiched in the circumferential direction by a pair of edges 32d and 32e formed on the rotor core 21. The pair of edges 32d and 32e are both formed in a straight line.

[0069] Fig.15 2 is a cross-sectional view showing a structure of a rotor 20 of a rotary electric machine 100 according to a modification 2-3 of the present embodiment cut perpendicularly to the axial direction. Fig.15 In the illustrated structure, the width of the second hole 32 does not necessarily increase monotonically as it moves away from the stator 10 in the radial direction. However, the width of the second hole 32 generally increases as it moves away from the stator 10 in the radial direction. The pair of edges 32d, 32e of the rotor core 21 are both formed in a concave curve shape.

[0070] Fig.16 2 is a cross-sectional view showing a structure of a rotor 20 of a rotating electrical machine 100 according to a modification 2-4 of the present embodiment cut perpendicularly to the axial direction. Fig.16 In the illustrated structure, the width of the second hole 32 increases monotonically as it moves away from the stator 10 in the radial direction. The pair of edge portions 32d and 32e of the rotor core 21 are both formed in a convex curve shape.

[0071] according to Figure 13 to Figure 16 The structure shown can also be Fig.11 The structure shown similarly improves the torque output of the rotating electric machine 100 .

[0072] As described above, in the rotary electric machine 100 of the present embodiment, the second hole 32 has the first portion 32a and the second portion 32b located radially closer to the stator 10 than the first portion 32a. When the width of the first portion 32a in the tangential direction along the circumferential direction is L1 and the width of the second portion 32b in the tangential direction is L2, the relationship of L1>L2 is satisfied. According to this structure, the circumferential leakage flux Φ2 at the portion far from the stator 10 can be reduced, so the torque output of the rotary electric machine 100 can be further improved.

[0073] In the rotary electric machine 100 of the present embodiment, the second hole 32 is formed so that the width in the tangential direction becomes wider as the second hole 32 is radially farther from the stator 10. According to this structure, the circumferential leakage flux Φ2 at a portion far from the stator 10 can be reduced, so the torque output of the rotary electric machine 100 can be further improved.

[0074] Implementation method 3.

[0075] A rotating electrical machine according to a third embodiment of the present invention will be described. Fig.17 It is a cross-sectional view showing the structure of the rotor 20 of the rotary electric machine 100 according to the present embodiment cut perpendicularly to the axial direction. Components having the same functions and effects as those of the first or second embodiment are denoted by the same reference numerals and their description is omitted.

[0076] like Fig.17 As shown in FIG. 1 , the rotor core 21 includes a plurality of core parts 40 sandwiched between two second holes 32 adjacent to each other in the circumferential direction. The permanent magnet 22 is provided for each of the plurality of core parts 40. The permanent magnets 22 are magnetized so that Fig.17 The magnetic pole facing counterclockwise is the N pole. Fig.17 The magnetic pole surface facing clockwise is the S pole.

[0077] The plurality of core parts 40 each include a first core part 41 located on the S-pole side of the permanent magnet 22 and a second core part 42 located on the N-pole side of the permanent magnet 22. Fig.17 In the illustrated rotor core 21 , since five core portions 40 are provided, five first core portions 41 and five second core portions 42 are provided.

[0078] The rotor core 21 includes a connecting portion 43 (hereinafter sometimes referred to as "first connecting portion 43") that connects the plurality of first core portions 41 to each other. The connecting portion 43 is arranged radially inward of the plurality of core portions 40. The connecting portion 43 includes: an annular portion 44 formed in an annular shape; and a plurality of radial portions 45 that extend radially from the annular portion 44 toward the plurality of first core portions 41 and connect the annular portion 44 to the plurality of first core portions 41. Thus, the plurality of first core portions 41 are magnetically connected to each other via the connecting portion 43.

[0079] On the other hand, each of the plurality of second core portions 42 is not directly connected to the radial portion 45 of the connection portion 43. Each of the plurality of second core portions 42 is connected to the connection portion 43 only via the first core portions 41 adjacent to each other with the permanent magnet 22 interposed therebetween.

[0080] According to the present embodiment, the plurality of first core parts 41 of the same pole are connected to each other via the connecting part 43, so that the generation of the circumferential leakage flux Φ2 can be suppressed. In addition, since the plurality of core parts 40 are integrated via the connecting part 43, the mechanical strength of the rotor 20 can be improved, and the productivity of the rotor 20 can be improved.

[0081] Here, in the present embodiment, the width of the second hole 32 increases as the distance from the stator 10 in the radial direction increases. However, similarly to the first embodiment, the width of the second hole 32 may be constant regardless of the radial position.

[0082] Fig.18 2 is a cross-sectional view showing a structure in which the rotor 20 of the rotating electrical machine 100 of the modification 3-1 of the present embodiment is cut perpendicularly to the axial direction. The rotor core 21 of the present modification has a connecting portion 46 (hereinafter sometimes referred to as "second connecting portion 46") that connects the plurality of second core portions 42 to each other. The connecting portion 46 has: an annular portion 44 formed in an annular shape; and a plurality of radial portions 45 that extend radially from the annular portion 44 toward the plurality of second core portions 42, respectively, and connect the annular portion 44 to the plurality of second core portions 42. Thus, the plurality of second core portions 42 are magnetically connected to each other via the connecting portion 46.

[0083] On the other hand, each of the plurality of first core parts 41 is not directly connected to the radial part 45 of the connecting part 46. Each of the plurality of first core parts 41 is connected to the connecting part 46 only via the second core parts 42 adjacent to each other across the permanent magnet 22. According to this modification, it is also possible to obtain the same Fig.17 The structure shown has the same effect.

[0084] In addition, the rotor 20 of this embodiment may also have Fig.17 The rotor core 21 and Fig.18The rotor core 21 shown is a structure in which the rotor core 21 is stacked in the axial direction. Fig.17 The rotor core 21 and Fig.18 The rotor cores 21 shown are alternately stacked in the axial direction, thereby further improving the mechanical strength of the rotor 20 .

[0085] Fig.19 2 is an exploded perspective view showing the structure of the rotor 20 of the rotating electrical machine 100 according to the modification 3-2 of the present embodiment. Fig.19 As shown in FIG. 1 , the rotor 20 of this modified example has a structure in which the first rotor core 51, the second rotor core 52, and the third rotor core 53 are stacked in the axial direction. The first rotor core 51, the second rotor core 52, and the third rotor core 53 are stacked in such a manner that the circumferential positions of the first holes 31 of the first rotor core 51, the second rotor core 52, and the third rotor core 53 are aligned. The permanent magnet 22 is inserted into the first hole 31 of the first rotor core 51, the second rotor core 52, and the third rotor core 53 so as to penetrate the first rotor core 51, the second rotor core 52, and the third rotor core 53.

[0086] When the first rotor core 51 is viewed from the inner side in the axial direction, Fig.17 The second rotor core 52 has the same structure as the rotor core 21 shown in FIG. Fig.18 The rotor core 21 shown has the same structure.

[0087] Fig. 20 2 is a cross-sectional view showing a structure of the third rotor core 53 of the rotating electrical machine 100 of this modified example cut perpendicularly to the axial direction. Fig. 20 As shown, the third rotor core 53 has a plurality of core parts 40 similarly to the first rotor core 51 and the second rotor core 52. The plurality of core parts 40 include a first core part 41 located on the S-pole side of the permanent magnet 22 and a second core part 42 located on the N-pole side of the permanent magnet 22.

[0088] The third rotor core 53 is different from the first rotor core 51 and the second rotor core 52 in that the connecting portion 43 is not provided. Therefore, the plurality of core portions 40 of the third rotor core 53 are separated from each other.

[0089] Return to Fig.19The rotor 20 has a structure in which the first rotor core 51, the third rotor core 53, and the second rotor core 52 are stacked in sequence in the axial direction. When a plurality of first rotor cores 51 or second rotor cores 52 are stacked, for example, the first rotor core 51, the third rotor core 53, the second rotor core 52, the third rotor core 53, the first rotor core 51, the third rotor core 53, the second rotor core 52, ... are stacked in sequence. The third rotor core 53 is sandwiched between the first rotor core 51 and the second rotor core 52. The axial thickness of the first rotor core 51 is thicker than the axial thickness of the third rotor core 53. Similarly, the axial thickness of the second rotor core 52 is thicker than the axial thickness of the third rotor core 53. Thus, the connecting portion 43 provided on the first rotor core 51 and the connecting portion 43 provided on the second rotor core 52 both have a constant thickness.

[0090] According to this modification, it is possible to suppress the leakage magnetic flux of the rotor 20 in the axial direction and to improve the mechanical strength of the rotor 20 .

[0091] Fig.21 3 is an exploded perspective view showing the structure of the rotor 20 of the rotating electrical machine 100 according to the modification 3-3 of the present embodiment. Fig.21 As shown in FIG. 1 , the rotor 20 of this modification further includes a pair of end plates 54 and 55. The end plates 54 and 55 are respectively arranged at both ends of the rotor core in the axial direction on which the first rotor core 51, the second rotor core 52, and the third rotor core 53 are stacked. The end plates 54 and 55 are fastened in the axial direction together with the first rotor core 51, the second rotor core 52, and the third rotor core 53 using a plurality of fastening members such as bolts 56. According to this modification, the mechanical strength of the rotor 20 can be further improved, and the rotor 20 can be formed as one piece.

[0092] As described above, in the rotating electric machine 100 of the present embodiment, the rotor core 21 has a plurality of core parts 40 sandwiched by two second holes 32 adjacent in the circumferential direction. The plurality of core parts 40 respectively have a first core part 41 located on one magnetic pole face side of the permanent magnet 22 and a second core part 42 located on the other magnetic pole face side of the permanent magnet 22. The rotor core 21 also has a connecting part 43 that connects the first core parts 41 of the plurality of core parts 40 to each other. According to this structure, the plurality of first core parts 41 of the same pole are connected to each other via the connecting part 43, so that the generation of the circumferential leakage flux Φ2 can be suppressed. Therefore, the torque of the rotating electric machine 100 can be improved. In addition, since the plurality of core parts 40 are integrated via the connecting part 43, the mechanical strength of the rotor 20 can be improved.

[0093] In the rotating electric machine 100 of the present embodiment, the rotor core 21 includes a first rotor core 51 and a second rotor core 52 which are stacked in the axial direction. The first rotor core 51 and the second rotor core 52 each include a plurality of core portions 40 sandwiched between two second holes 32 adjacent in the circumferential direction. The plurality of core portions 40 each include a first core portion 41 located on one magnetic pole face side of the permanent magnet 22 and a second core portion 42 located on the other magnetic pole face side of the permanent magnet 22. The first rotor core 51 further includes a first connecting portion 43 connecting the first core portions 41 of the first rotor core 51. The second rotor core 52 further includes a second connecting portion 46 connecting the second core portions 42 of the second rotor core 52. According to this structure, in the first rotor core 51, the plurality of first core portions 41 of the same pole are connected to each other via the connecting portion 43, so that the generation of the circumferential leakage flux Φ2 can be suppressed. In addition, in the second rotor core 52, the plurality of second core portions 42 of the same pole are connected to each other via the connection portion 46, so that the generation of the circumferential leakage flux Φ2 can be suppressed. Therefore, the torque of the rotating electric machine 100 can be improved. In addition, since the first rotor core 51 and the second rotor core 52 are stacked in the axial direction, the mechanical strength of the rotor 20 can be further improved.

[0094] In the rotating electric machine 100 of the present embodiment, the rotor core 21 includes a first rotor core 51, a second rotor core 52, and a third rotor core 53 which are stacked in the axial direction. The first rotor core 51, the second rotor core 52, and the third rotor core 53 each include a plurality of core portions 40 sandwiched between two second holes 32 adjacent in the circumferential direction. The plurality of core portions 40 each include a first core portion 41 located on one magnetic pole face side of the permanent magnet 22 and a second core portion 42 located on the other magnetic pole face side of the permanent magnet 22. The first rotor core 51 further includes a first connecting portion 43 connecting the first core portions 41 of the first rotor core 51 to each other. The second rotor core 52 further includes a second connecting portion 46 connecting the second core portions 42 of the second rotor core 52 to each other. The plurality of core portions 40 of the third rotor core 53 are not connected to each other in the third rotor core 53. In the axial direction, the third rotor core 53 is arranged between the first rotor core 51 and the second rotor core 52. According to this structure, in the first rotor core 51, a plurality of first core parts 41 of the same pole are connected to each other via the connecting part 43, so that the generation of circumferential leakage flux Φ2 can be suppressed. In addition, in the second rotor core 52, a plurality of second core parts 42 of the same pole are connected to each other via the connecting part 46, so that the generation of circumferential leakage flux Φ2 can be suppressed. And, between the first rotor core 51 and the second rotor core 53, a third rotor core 53 in which a plurality of core parts 40 are not connected to each other is arranged, so that the generation of axial leakage flux can be suppressed. Therefore, the torque of the rotating electric machine 100 can be improved.

[0095] Implementation method 4.

[0096] A rotating electrical machine according to a fourth embodiment of the present invention will be described. Fig. 22 It is a cross-sectional view showing the structure of the rotor 20 of the rotary electric machine 100 according to the present embodiment cut perpendicularly to the axial direction. Components having the same functions and effects as those in any of the first to third embodiments are denoted by the same reference numerals and their description is omitted.

[0097] like Fig. 22 As shown, in the present embodiment, the first hole 31 into which the permanent magnet 22 is inserted has a third opening 35 which opens radially toward the stator 10 side, that is, radially toward the outside. Since the permanent magnet 22 is not inserted in the third opening 35, the third opening 35 becomes a circumferential magnetic gap in the outer periphery of the rotor core 21. The third opening 35 may also be a space. Alternatively, the third opening 35 may be filled with a non-magnetic component. Fig. 22 In the structure shown, Figure 8 In the illustrated structure, the width of the first hole 31 in the tangential direction along the circumferential direction is similarly narrower than the width of the second hole 32 in the tangential direction along the circumferential direction.

[0098] In the structures of the above-mentioned embodiments 1 to 3, the radially outer side of the first hole 31 is closed. The first core portion 41 located on the S-pole side of the permanent magnet 22 is magnetized to the S-pole, and the second core portion 42 located on the N-pole side of the permanent magnet 22 is magnetized to the N-pole. Therefore, between the second core portion 42 and the first core portion 41, a closed magnetic circuit is formed in which the magnetic flux from the permanent magnet 22 returns to the permanent magnet 22 through the radially outer side of the first hole 31. The magnetic flux passing through the closed magnetic circuit becomes leakage flux that does not interlink with the stator 10. If the leakage flux can be suppressed, the effective magnetic flux Φ1 interlinked with the stator 10 can be increased, and therefore, the torque output of the rotating electric machine 100 can be improved.

[0099] In this embodiment, since the third opening 35 is formed radially outside the first hole 31, the magnetic resistance of the closed magnetic circuit is increased. Fig. 22 The leakage flux shown by the dotted arrow in the middle can be reduced, thereby improving the torque output of the rotating electrical machine 100. When the width of the first hole 31 is narrower than the width of the second hole 32, the leakage flux is likely to occur. However, in the present embodiment, the third opening 35 is formed, so even when the width of the first hole 31 is narrower than the width of the second hole 32, the leakage flux can be effectively suppressed.

[0100] Fig.234-1 is a cross-sectional view showing a structure in which the rotor 20 of the rotating electrical machine 100 according to the modification 4-1 of the present embodiment is cut perpendicularly to the axial direction. Fig.23 As shown in FIG. 1 , the first hole 31 of this modification has a fourth opening 36 that opens radially toward the side opposite to the stator 10, that is, radially toward the inside. A closed magnetic circuit in which the magnetic flux from the permanent magnet 22 returns to the permanent magnet 22 is also formed radially inside the first hole 31. In this modification, the magnetic resistance of the closed magnetic circuit formed radially inside the first hole 31 is increased. This can suppress the Fig.23 The leakage magnetic flux indicated by the broken-line arrow is reduced, and therefore, the torque output of the rotating electrical machine 100 can be improved.

[0101] In the structure of this modification, the width of the first hole 31 is also narrower than the width of the second hole 32. However, in the structure of this modification, since the fourth opening 36 is formed, even when the width of the first hole 31 is narrower than the width of the second hole 32, the leakage flux can be effectively suppressed.

[0102] Fig.24 4 is a cross-sectional view showing a structure in which the rotor 20 of the rotating electrical machine 100 according to the modification 4-2 of the present embodiment is cut perpendicularly to the axial direction. Fig.24 As shown, the first hole 31 of this modification has both the third opening 35 and the fourth opening 36. According to this modification, both of the above-mentioned two effects can be obtained, so the torque output of the rotating electrical machine 100 can be further improved.

[0103] In the structure of this modified example, the width of the first hole 31 is also narrower than the width of the second hole 32. However, in the structure of this modified example, since the third opening 35 and the fourth opening 36 are formed, even when the width of the first hole 31 is narrower than the width of the second hole 32, the leakage magnetic flux can be effectively suppressed.

[0104] As described above, in the rotating electric machine 100 of the present embodiment, the first hole 31 has the third opening portion 35 opened radially toward the stator 10 or the fourth opening portion 36 opened radially toward the side opposite to the stator 10. According to this structure, leakage flux can be suppressed, and thus the torque output of the rotating electric machine 100 can be improved.

[0105] Implementation method 5.

[0106] A rotating electrical machine according to a fifth embodiment of the present invention will be described. Fig.25 It is a cross-sectional view showing the structure of the rotor 20 of the rotary electric machine 100 according to the present embodiment cut perpendicularly to the axial direction. Components having the same functions and effects as those in any of the first to third embodiments are denoted by the same reference numerals and their description is omitted.

[0107] As shown Fig.25 in the figure, the rotor core 21 is separated into a plurality of core portions 40 by the second hole 32. The second hole 32 is circumferentially sandwiched by a flange portion 32d and a flange portion 32e. One flange portion 32d is formed in the core portion 40 adjacent in the counterclockwise direction with respect to the second hole 32 in Fig.25 it. A concave portion 37 is formed in a part of the flange portion 32d by making a cutout in a concave shape. The flange portion 32d other than the concave portion 37 is formed in a straight line shape. The other flange portion 32e is formed in the core portion 40 adjacent in the clockwise direction with respect to the second hole 32 in Fig.25 it. A concave portion 38 is formed in a part of the flange portion 32e by making a cutout in a concave shape. The flange portion 32e other than the concave portion 38 is formed in a straight line shape.

[0108] When the rotor 20 rotates, a centrifugal force directed radially outward is generated. Therefore, the plurality of separated core portions 40 may fly out toward the outer peripheral side during rotation. When the core portion 40 flies out toward the outer peripheral side, there is a possibility that the rotating electrical machine 100 stops due to contact with the stator 10.

[0109] In the present embodiment, a holding member (not shown) formed of a nonmagnetic material such as resin or nonmagnetic metal is inserted into the second hole 32. A convex portion that fits into the concave portion 37 and another convex portion that fits into the concave portion 38 are formed in the holding member. Since each core portion 40 is held by the holding member, it is possible to prevent the core portion 40 from flying out toward the outer peripheral side. In addition, the positioning accuracy of the rotor core 21 in the circumferential direction is improved by the holding member. And, by improving the positioning accuracy of the rotor core 21 using the holding member, an increase in torque ripple due to the influence of rotor deviation can be suppressed.

[0110] In Fig.25 the structure shown in the figure, the opening width Lo1 of the first opening portion 33 in the tangential direction along the circumferential direction is narrower than the opening width Lo2 of the second opening portion 34 in the tangential direction along the circumferential direction (Lo1 < Lo2). However, the opening width Lo1 of the first opening portion 33 may also be the same as the opening width Lo2 of the second opening portion 34 (Lo1 = Lo2). In addition, the width of the second hole 32 may also change stepwise as shown in Fig.11 and Fig.13 the figure.

[0111] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. For example, in the above-mentioned embodiment, a 10-pole rotor 20 is listed, but the present invention is not limited to this. Even if the number of magnetic poles p (wherein p is an even number greater than 2) of the rotor 20 is other than 10, the same effect as in the above-mentioned embodiment can be obtained. In addition, in the above-mentioned embodiment, a stator 10 having 12 teeth 13 and 12 windings 14 is listed, but the present invention is not limited to this. The number of teeth 13 and the number of windings 14 can also be set to appropriate numbers according to the number of magnetic poles of the rotor 20.

[0112] In the above embodiment, the rotary electric machine 100 in which the rotor 20 is arranged on the inner circumference side of the stator 10 is described as an example, but the present invention is also applicable to a rotary electric machine in which the rotor 20 is arranged on the outer circumference side of the stator 10 .

[0113] The above-mentioned embodiments 1 to 5 and the modifications can be implemented in combination with each other.

[0114] Description of Reference Numerals

[0115] 10 stator, 11 stator core, 12 core back, 13 teeth, 14 winding, 15 gap, 20 rotor, 21 rotor core, 21a outer peripheral surface, 22 permanent magnet, 30 hole, 31 first hole, 32 second hole, 32a first part, 32b second part, 32c third part, 32d, 32e edge, 33 first opening, 34 second opening, 35 third opening, 36 fourth opening, 37, 38 recess, 40 core part, 41 first core part, 42 second core part, 43, 46 connecting part, 44 annular part, 45 radial part, 51 first rotor core, 52 second rotor core, 53 third rotor core, 54, 55 end plate, 56 bolt, 100, 200 rotating electrical machine, 201, 202 connecting part, Φ1 effective magnetic flux, Φ2 circumferential leakage magnetic flux.

Claims

1. A rotating electrical machine, wherein: The rotating electrical machine comprises: stator; and a rotor rotatably arranged relative to the stator, The rotor has: a rotor core having a plurality of holes arranged in a circumferential direction of the rotor; as well as at least one permanent magnet, The number of magnetic poles of the rotor is an even number p greater than 2, The plurality of holes include p / 2 first holes into which the permanent magnets are inserted and p / 2 second holes into which the permanent magnets are not inserted. The first holes and the second holes are arranged alternately in the circumferential direction. The permanent magnet is magnetized so that the magnetic pole faces facing each other in the circumferential direction with the second hole interposed therebetween have different poles. The second hole has a first opening portion opened toward the stator in the radial direction of the rotor and a second opening portion opened toward the side opposite to the stator in the radial direction. In a portion of the second hole between the first opening and the second opening, a width of the second hole in a tangential direction along the circumferential direction gradually increases in the radial direction from the stator side toward a side opposite to the stator.

2. The rotating electrical machine according to claim 1, wherein: The second hole includes a first portion and a second portion located closer to the stator than the first portion in the radial direction. When the width of the first portion in the tangential direction along the circumferential direction is L1 and the width of the second portion in the tangential direction is L2, a relationship of L1>L2 is satisfied.

3. The rotating electrical machine according to claim 2, wherein: The second hole is formed so that the width in the tangential direction increases monotonically as the second hole becomes farther away from the stator in the radial direction.

4. The rotating electrical machine according to any one of claims 1 to 3, wherein: When the opening width of the first opening is represented by Lo1 and the maximum value of the interval between the stator and the rotor in the radial direction is represented by Gmmax, the relationship of Lo1>Gmmax is satisfied.

5. The rotating electrical machine according to any one of claims 1 to 3, wherein: The first hole has a third opening portion opened toward the stator in the radial direction or a fourth opening portion opened toward the side opposite to the stator in the radial direction.

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