Rotating electric machines

Abstract

The rotating electrical machine includes a stator and a rotor, the rotor having a rotor core and a plurality of permanent magnets, a plurality of holes including a plurality of first holes and a plurality of second holes being formed in the rotor core, the plurality of permanent magnets being inserted only into each of the plurality of first holes among the plurality of holes, the rotor core having a plurality of core portions, the rotor core having an annular portion and a plurality of connecting portions, the plurality of connecting portions respectively connecting the annular portion to the first core portion of each of the plurality of core portions, the plurality of connecting portions each having at least one connecting path, the sum of the widths of the narrowest portions in each of the at least one connecting path being shorter than the length of the joining boundary between the annular portion and each of the plurality of connecting portions.

Description

Technical Field

[0001] The present disclosure relates to a rotating electrical machine including a rotor having a rotor core and a plurality of permanent magnets provided on the rotor core. Background Art

[0002] Patent Document 1 describes an embedded-magnet motor. In this embedded-magnet motor, the rotor's annular surface is alternately circumferentially arranged with rectangular slits, each half the number of motor poles, and rectangular permanent magnets, the same number of slits. Segmented regions, equal in number to the number of motor poles, are formed between each slit and the permanent magnet. These segments are magnetized alternately with north and south poles along the circumferential direction.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-200480 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the rotor of the aforementioned embedded-magnet motor, two adjacent segmented regions sandwiching a slit are connected via a connecting portion located inner and outer of the slit. Consequently, a closed magnetic circuit is formed in the rotor, with magnetic flux flowing circumferentially through these connecting portions. This leads to a problem: increased circumferential leakage flux that does not interlink with the stator reduces the motor's torque output.

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

[0009] Means for solving problems

[0010] The rotating electric machine disclosed herein comprises: a stator; and a rotor, the rotor being arranged on the inner circumference side of the stator in a manner rotatable relative to the stator, the rotor having: a rotor core; a plurality of permanent magnets, the plurality of permanent magnets being arranged on the rotor core; and a shaft, the shaft being fixed to a central portion of the rotor core and extending in the axial direction of the rotor, the rotor core being formed with a plurality of holes arranged in a circumferential direction of the rotor, the plurality of holes including a plurality of first holes and a plurality of second holes, the plurality of permanent magnets being respectively inserted only into each of the plurality of first holes among the plurality of holes, the plurality of first holes and the plurality of second holes being alternately arranged one by one in the circumferential direction, the rotor core having a plurality of core parts, the plurality of core parts being arranged in the circumferential direction with each of the plurality of second holes sandwiched therebetween, the plurality of permanent magnets being arranged in a manner such that magnetic pole surfaces facing each other in the circumferential direction have different poles. The cam is magnetized, and the plurality of core parts respectively include: a first core part, the first core part being located on the magnetic pole face side of one side of each of the plurality of permanent magnets; and a second core part, the second core part being located on the magnetic pole face side of the other side of each of the plurality of permanent magnets. The rotor core has a first rotor core in at least a portion of the axial direction, the first rotor core having a first annular part and a plurality of first connecting parts, the first annular part being arranged at a position closer to the inner circumference than the plurality of core parts and being configured for the shaft to be inserted, the plurality of first connecting parts respectively connecting the first annular part to the first core part of each of the plurality of core parts, the plurality of first connecting parts respectively having at least one connecting path, the sum of the widths of the narrowest parts in each of the at least one connecting path being shorter than the length of the arc-shaped joining boundary between the first annular part and each of the plurality of first connecting parts.

[0011] Effects of the Invention

[0012] According to the present disclosure, 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 a structure of a rotating electrical machine serving as a premise of the first embodiment, 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 first comparative example of the first embodiment, cut perpendicularly to the axial direction.

[0015] Figure 3 It is shown enlarged Figure 2 Part of the diagram.

[0016] Figure 4 This is a cross-sectional view showing a structure of a rotating electrical machine according to a second comparative example of the first embodiment, cut perpendicularly to the axial direction.

[0017] Figure 5 It is shown enlarged Figure 4 Part of the diagram.

[0018] Figure 6 This is a cross-sectional view showing a structure of another rotating electrical machine serving as a premise of the first embodiment, cut perpendicularly to the axial direction.

[0019] Figure 7 Graphs showing torque obtained by the rotating electric machine serving as a premise of the first embodiment and torque obtained by the rotating electric machine of the first comparative example.

[0020] Figure 8 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the first embodiment perpendicularly to the axial direction.

[0021] Figure 9 It is shown in Figure 1 The maximum stress generated in the connection part of the rotor with the structure shown in FIG. Figure 8 Graph showing the maximum stress generated in the connection portion during rotation in a rotor having the structure shown.

[0022] Figure 10 This is a cross-sectional view showing a structure obtained by cutting a rotor of a rotating electrical machine according to a third comparative example of the first embodiment perpendicularly to the axial direction.

[0023] Figure 11 It shows that Figure 8 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 10 A graph showing the torque obtained by rotating an electric machine having a rotor having the structure shown.

[0024] Figure 12 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 1-1 of Embodiment 1 perpendicularly to the axial direction.

[0025] Figure 13 It is shown enlarged Figure 12 Part of the diagram.

[0026] Figure 14 This is a cross-sectional view showing a structure obtained by cutting the shaft of the rotating electrical machine according to Modification 1-2 of Embodiment 1 perpendicularly to the axial direction.

[0027] Figure 15 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the second embodiment perpendicularly to the axial direction.

[0028] Figure 16 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 2-1 of Embodiment 2 perpendicularly to the axial direction.

[0029] Figure 17 It shows that Figure 16 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 10 A graph showing the torque obtained by rotating an electric machine having a rotor having the structure shown.

[0030] Figure 18 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 2-2 of Embodiment 2 perpendicularly to the axial direction.

[0031] Figure 19 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 2-3 of Embodiment 2 perpendicularly to the axial direction.

[0032] Figure 20 This is an exploded perspective view showing the structure of a rotor of a rotating electrical machine according to Modification 2-4 of Embodiment 2.

[0033] Figure 21 It is an exploded perspective view showing the structure of a rotor of a rotating electrical machine according to Modification 2-5 of Embodiment 2.

[0034] Figure 22 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 2-6 of Embodiment 2 perpendicularly to the axial direction.

[0035] Figure 23 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 2-7 of Embodiment 2 perpendicularly to the axial direction.

[0036] Figure 24 It shows that Figure 22 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 23 A graph showing the torque obtained by rotating an electric machine having a rotor having the structure shown.

[0037] Figure 25 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the third embodiment perpendicularly to the axial direction.

[0038] Figure 26 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 3-1 of Embodiment 3 perpendicularly to the axial direction.

[0039] Figure 27 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.

[0040] Figure 28 This is a diagram illustrating the width of a connection path. DETAILED DESCRIPTION

[0041] Implementation method 1.

[0042] The rotating electrical machine according to the first embodiment will be described. First, the rotating electrical machine serving as a premise of the first embodiment will be described. Figure 1 This is a cross-sectional view showing the structure of the rotating electrical machine, which is the premise of this embodiment, cut perpendicularly to the axial direction. Here, the direction along the axis O of the rotor 20 is referred to as the axial direction. In a cross section of the rotor 20 perpendicular to the axial direction, the direction along the radius of the rotor 20 is referred to as the radial direction. The direction along the rotational direction of the rotor 20, i.e., the direction along the circumference centered on the axis O in the cross section, is referred to as the circumferential direction.

[0043] like Figure 1 As shown, the rotary electric machine 100 includes a stator 10 and a rotor 20 rotatably provided on the inner circumference of the stator 10. A gap 15 serving as a magnetic gap is formed between the stator 10 and the rotor 20.

[0044] The stator 10 is provided so as to surround the outer periphery of the rotor 20. The stator 10 includes a stator core 11 and a plurality of windings 14. The stator core 11 includes a core back 12 formed in an annular shape and a plurality of teeth 13 protruding from the core back 12 toward the inner periphery. The plurality of windings 14 are respectively wound around the plurality of teeth 13 in a concentrated winding manner. Figure 1 In the structure shown, twelve teeth 13 and twelve windings 14 are provided.

[0045] As described later Figure 2 As shown, the core back 12 may also have a structure in which a plurality of arc-shaped core blocks are connected to form a circular ring. Furthermore, the number of teeth 13 nt and the number of windings 14 nc satisfy the relationship nc ≤ nt, and the numbers of teeth 13 and windings 14 are not limited to the above numbers.

[0046] The rotor 20 includes a rotor core 21, a plurality of permanent magnets 22 disposed within the rotor core 21, and a shaft 23 disposed on the inner circumference of the rotor core 21. The rotor 20 is a longitudinally embedded magnet rotor in which the plurality of permanent magnets 22 are radially arranged within the rotor core 21. This longitudinally embedded magnet rotor is sometimes also referred to as a spoke rotor.

[0047] The rotor 20 is a commutation-pole type rotor in which the number of permanent magnets 22 is less than the number of magnetic poles. When the number of magnetic poles is p, the rotor 20 has p / 2 permanent magnets 22. Here, p is an even number greater than 2. Figure 1 In the illustrated structure, since the number of magnetic poles p of the rotor 20 is 10, the number of permanent magnets 22 is five.

[0048] The rotor core 21 is constructed by stacking multiple core plates made of magnetic material in the axial direction. A plurality of holes 30 are formed in the rotor core 21, extending axially therethrough. These holes 30 are arranged circumferentially around the rotor 20. In a cross-section of the rotor 20 perpendicular to the axial direction, the holes 30 are radially arranged with their longitudinal directions extending radially. The number of holes 30 is p, which is equal to the number of magnetic poles in the rotor 20.

[0049] Permanent magnets 22 are inserted into some of the holes 30. That is, the holes 30 include a plurality of first holes 31 into which permanent magnets 22 are inserted and a plurality of second holes 32 into which no permanent magnets 22 are inserted. Permanent magnets 22 are inserted only into each of the first holes 31 in the holes 30. The number of first holes 31 and the number of second holes 32 are both p / 2. Figure 1 In the structure shown, since the number of magnetic poles p is 10, the number of first holes 31 and the number of second holes 32 are both 5. The plurality of first holes 31 and the plurality of second holes 32 are arranged alternately one by one in the circumferential direction of the rotor 20. In other words, the plurality of first holes 31 and the plurality of second holes 32 are arranged alternately one by one on the circumference centered on the axis O of the rotor 20. Figure 1 In the structure shown, the shape of the first hole 31 and the shape of the second hole 32 are different from each other, but the shape of the first hole 31 and the shape of the second hole 32 may also be the same.

[0050] The first hole 31 has an outer peripheral opening 33 that opens radially outward, i.e., toward the stator 10, and an inner peripheral opening 34 that opens radially inward, i.e., toward the shaft 23. That is, the first hole 31 opens radially both outward and inward.

[0051] The second hole 32 has an outer peripheral opening 35 that opens radially outward, that is, toward the stator 10, and an inner peripheral opening 36 that opens radially inward, that is, toward the shaft 23. That is, the second hole 32 opens radially both outward and inward. The outer peripheral opening 35 forms a magnetic gap along the circumferential magnetic path on the outer periphery of the rotor core 21. The inner peripheral opening 36 forms a magnetic gap along the circumferential magnetic path on the inner periphery of the rotor core 21. The circumferential width of the second hole 32 increases from the outer periphery toward the inner periphery. However, the circumferential width of the second hole 32 may also be constant in the radial direction.

[0052] The interior of the second hole 32 is a space. A non-magnetic member formed of a non-magnetic material such as resin or non-magnetic metal may be inserted into the interior of the second hole 32. The rotor core 21 may be held by the non-magnetic member inserted into the interior of the second hole 32.

[0053] The plurality of permanent magnets 22 inserted into the plurality of first holes 31 are radially arranged in a cross section of the rotor 20 perpendicular to the axial direction. In this cross section, the length direction of the permanent magnets 22 is along the radial direction of the rotor 20. The plurality of permanent magnets 22 are arranged in the circumferential direction. Two permanent magnets 22 adjacent to each other in the circumferential direction with the second hole 32 sandwiched therebetween are magnetized so that the two magnetic pole faces facing each other in the circumferential direction become different poles. For example, the plurality of permanent magnets 22 are magnetized so that: Figure 1 The magnetic pole facing counterclockwise is the N pole. Figure 1 The magnetic pole face facing clockwise is an S pole. The magnetization direction of each permanent magnet 22 is along the circumferential direction of the rotor 20. The permanent magnets 22 are fixed to the rotor core 21 using an adhesive or the like.

[0054] The rotor core 21 has a plurality of core parts 40. In a cross section of the rotor 20 perpendicular to the axial direction, the plurality of core parts 40 are each formed in a fan-shaped shape. The plurality of core parts 40 are arranged in the circumferential direction with each of the plurality of second holes 32 sandwiched therebetween. The number of core parts 40 is p / 2. Figure 1 In the illustrated structure, since the number of magnetic poles p is 10, the number of core portions 40 is 5. One second hole 32 is disposed between two circumferentially adjacent core portions 40. In other words, each core portion 40 is sandwiched between two circumferentially adjacent second holes 32.

[0055] Each of the core sections 40 is provided with a first hole 31. Specifically, each of the core sections 40 is provided with a permanent magnet 22. In a cross section perpendicular to the axial direction, the outer peripheral end of the permanent magnet 22 is positioned within the outer peripheral opening 33 and constitutes the outer peripheral end of the core section 40. In this cross section, the inner peripheral end of the permanent magnet 22 is positioned within the inner peripheral opening 34 and constitutes the inner peripheral end of the core section 40.

[0056] Each of the plurality of core portions 40 includes a first core portion 41 located on one magnetic pole surface side of the permanent magnet 22 and a second core portion 42 located on the other magnetic pole surface side of the permanent magnet 22. Figure 1 In the structure shown, the first core portion 41 is located on the S-pole side of the permanent magnet 22 in each of the plurality of core portions 40, and the second core portion 42 is located on the N-pole side of the permanent magnet 22 in each of the plurality of core portions 40. Figure 1 In the illustrated structure, since five core parts 40 are provided, five first core parts 41 and five second core parts 42 are provided.

[0057] In each of the plurality of core sections 40, the first core section 41 and the second core section 42 are bonded together using an adhesive or the like, with the permanent magnet 22 interposed therebetween. Since the first core section 41 is in contact with the south pole of the permanent magnet 22, it is magnetized to the south pole. Since the second core section 42 is in contact with the north pole of the permanent magnet 22, it is magnetized to the north pole.

[0058] At least Figure 1 In the cross section shown, the rotor core 21 further includes an annular portion 50 and a plurality of connecting portions 51. The annular portion 50 and the plurality of connecting portions 51 are configured to connect the plurality of core portions 40 to each other.

[0059] The annular portion 50 has an annular shape centered on the axis O of the rotor 20 and is provided on the inner circumference of the plurality of core portions 40. The annular portion 50 is configured such that the shaft 23 is inserted therein. The shaft 23 is disposed on the axis O of the rotor 20 and extends in the axial direction.

[0060] The plurality of connecting portions 51 extend radially from the annular portion 50 toward the first core portions 41 of the plurality of core portions 40. One end of each of the plurality of connecting portions 51 is connected to the annular portion 50. The other end of each of the plurality of connecting portions 51 is connected, for example, to the inner circumferential end of the first core portion 41. However, the other end of each of the plurality of connecting portions 51 may be connected to a portion of the first core portion 41 other than the inner circumferential end.

[0061] The plurality of coupling portions 51 couple the annular portion 50 to each of the plurality of first core portions 41 . As a result, the plurality of first core portions 41 are magnetically coupled to one another via the annular portion 50 and the plurality of coupling portions 51 .

[0062] On the other hand, each of the plurality of connecting portions 51 is not directly connected to the second core portion 42 of each of the plurality of core portions 40. In a cross section perpendicular to the axial direction, the second core portion 42 is connected to the connecting portion 51 and the annular portion 50 only via the adjacent first core portion 41 with the permanent magnet 22 interposed therebetween.

[0063] Figure 2 : is a cross-sectional view showing a structure obtained by cutting the rotating electrical machine of the first comparative example of the present embodiment perpendicularly to the axial direction. Figure 2 As shown, the rotor 20 of the rotary electric machine 200 of this comparative example is different from the embodiment in that at least the second hole 32 does not have the outer peripheral opening 35 and the inner peripheral opening 36. Figure 1 The rotor 20 of the illustrated rotating electrical machine 100 is different. In the rotor 20 of this comparative example, the radially outer side of the second hole 32 is closed by a connecting portion 201, and the radially inner side of the second hole 32 is closed by a connecting portion 202. Connecting portions 201 and 202 are part of the rotor core 21 and are formed of a magnetic material.

[0064] Figure 3 It is shown enlarged Figure 2 A portion of the diagram. Figure 3In FIG. 1 , solid arrows indicate effective magnetic flux Φ1 that interlinks with stator 10 and contributes to the torque of rotating electrical machine 200 , and dashed arrows indicate circumferential leakage magnetic flux Φ2 that passes through a circumferential closed magnetic path within rotor core 21 .

[0065] The magnetic resistance of the connection portion 201 that closes the radial outer side of the second hole 32 and the connection portion 202 that closes the radial inner side of the second hole 32 are each very low compared to the magnetic resistance of the gap 15. Therefore, a closed circumferential magnetic circuit is actively formed in the rotor core 21, and it is difficult to form a magnetic circuit that causes the magnetic flux to interlink with the stator 10. Therefore, relative to the amount of permanent magnets 22 used, the circumferential leakage magnetic flux Φ2 passing through the connection portion 202 or the connection portion 201 becomes relatively large, and therefore the effective magnetic flux Φ1 passing through the gap 15 and interlinking with the stator 10 becomes less. Therefore, in Figure 2 and Figure 3 In the structure of the first comparative example shown, it is difficult to increase the torque output of the rotating electric machine 200 .

[0066] Figure 4 : is a cross-sectional view showing a structure obtained by cutting the rotating electrical machine according to the second comparative example of the present embodiment perpendicularly to the axial direction. Figure 4 As shown, in the rotor 20 of the rotary electric machine 300 of this comparative example, Figure 1 The second hole 32 has an outer peripheral opening 35 and an inner peripheral opening 36, similarly to the rotor 20 shown in FIG. Figure 1 The illustrated rotor 20 is different in that the plurality of connection portions 51 that respectively connect the annular portion 50 and the plurality of first core portions 41 are not formed.

[0067] Figure 5 It is shown enlarged Figure 4 A portion of the diagram. Figure 5 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 5 As shown, since the closed circumferential magnetic circuit within the rotor core 21 necessarily passes through the second hole 32, the magnetic resistance of the closed circumferential magnetic circuit is increased. This reduces the circumferential leakage flux Φ2 and increases the effective magnetic flux Φ1 interlinked with the stator 10. In particular, when the circumferential width of the second hole 32 increases toward the inner circumference, the circumferential leakage flux Φ2 near the inner circumference of the rotor core 21 can be effectively reduced.

[0068] However, in Figure 4 and Figure 5 In the structure of the second comparative example shown, since the plurality of connection portions 51 connecting the annular portion 50 and the plurality of first core portions 41 are not formed, it is difficult to transmit torque between the rotor core 21 and the shaft 23 .

[0069] In contrast, in Figure 1 In the illustrated rotating electrical machine 100 , the annular portion 50 and the plurality of first core portions 41 are physically connected via the plurality of connection portions 51 . Therefore, torque can be reliably transmitted between the rotor core 21 and the shaft 23 .

[0070] Figure 6 This is a cross-sectional view showing a structure of another rotating electrical machine serving as a premise of the present embodiment, cut perpendicularly to the axial direction. Figure 6 The shapes of the core portion 40 and the second hole 32 shown are similar to those of Figure 1 The shapes of the core portion 40 and the second hole 32 are shown to be different. Figure 6 In the illustrated structure, the first core portion 41 of the core portion 40 has a partially cylindrical inner circumferential surface 41a at its inner circumferential end, centered on the axis O of the rotor 20. Similarly, the second core portion 42 of the core portion 40 has a partially cylindrical inner circumferential surface 42a at its inner circumferential end, centered on the axis O of the rotor 20. The connecting portion 51 is connected to the inner circumferential surface 41a of the first core portion 41 at a position close to the permanent magnet 22.

[0071] exist Figure 1 In the structure shown, at the joint portion between the connecting portion 51 and the first core portion 41, the angle θ1 formed between the side surface of the connecting portion 51 and the side surface of the first core portion 41 is an obtuse angle. Figure 6 In the structure shown, at the junction of the connecting portion 51 and the first core portion 41, the angle θ2 formed between the side surface of the connecting portion 51 and the inner circumferential surface 41a of the first core portion 41 is an obtuse angle, but smaller than the angle θ1. In order to avoid stress concentration at the junction of the connecting portion 51 and the first core portion 41, as shown in FIG. Figure 1 As in the illustrated structure, it is desirable that the angle θ1 formed between the side surface of the connection portion 51 and the side surface of the first core portion 41 be an obtuse angle and a larger angle.

[0072] exist Figure 6 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 6 As shown in FIG. 1 , the circumferential closed magnetic circuit in the rotor core 21 passes through the connecting portion 51 and the annular portion 50. Figure 1 In the structure shown, the closed circumferential magnetic circuit closed in the rotor core 21 also passes through the connecting portion 51 and the annular portion 50. Figure 1 and Figure 6 The structure shown can reduce the circumferential leakage magnetic flux Φ2 at least near the outer periphery of the rotor core 21. Therefore, the effective magnetic flux Φ1 interlinked with the stator 10 can be increased.

[0073] In addition, Figure 1 and Figure 6 In the structure shown, since the plurality of first core portions 41 magnetized to the same pole are connected to each other via the connecting portion 51 and the annular portion 50, the circumferential leakage flux Φ2 passing through the connecting portion 51 and the annular portion 50 can also be reduced. As a result, the effective magnetic flux Φ1 interlinked with the stator 10 can be further increased. Figure 1 and Figure 6 The rotating electrical machine 100 as shown in the figure, which is the premise of this embodiment, is Figure 2 and Figure 3 Compared with the rotating electrical machine 200 of the first comparative example shown, the torque output can be improved.

[0074] Figure 7 Graph showing torque obtained by the rotating electrical machine serving as the premise of this embodiment and torque obtained by the rotating electrical machine of Comparative Example 1. The vertical axis of the graph represents torque [pu] obtained by normalizing the torque obtained by the rotating electrical machine 200 of Comparative Example 1 to 1. Figure 7 In the Figure 2 The structure of the first comparative example " represents the rotating electrical machine 200," Figure 1 The “structure” indicates the rotating electrical machine 100 that is a premise of the present embodiment.

[0075] like Figure 7 As shown, when the torque obtained by the rotating electric machine 200 of the first comparative example is set to 1, the torque obtained by the rotating electric machine 100, which is the premise of this embodiment, is approximately 3.66. Therefore, it can be seen that the rotating electric machine 100, which is the premise of this embodiment, can obtain a higher torque than the rotating electric machine 200 of the first comparative example.

[0076] Figure 8 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to this embodiment perpendicularly to the axial direction. Figure 8 Although not shown in the figure, the stator 10 is provided on the outer peripheral side of the rotor 20 with a gap 15 therebetween. Figure 8 As shown, in the rotor 20 of the present embodiment, the circumferential width of the connection portion 51 is non-uniform in the radial direction of the rotor 20 .

[0077] exist Figure 8 In the cross section shown, the connecting portion 51 has a connecting path 51a. The connecting path 51a constitutes the path of the magnetic circuit formed in the connecting portion 51. Figure 15 As described above, the connection portion 51 may include a plurality of connection paths 51 a and 51 c provided in parallel with each other.

[0078] Here, refer to Figure 28 ,right Figure 8 The width of the connecting path 51a in the cross section shown will be described. Figure 28 This figure explains the width of the connection path. The width of the connection path 51a is determined at each point on the center line 51a1 of the connection path 51a. The center line 51a1 is a line that passes through the center of the connection path 51a and connects the annular portion 50 and the first core portion 41.

[0079] Let t0 be the width of the connecting path 51a at any point P0 on the center line 51a1. The width t0 of the connecting path 51a at point P0 is the length of the shortest straight line passing through point P0 and connecting one side surface 51a2 of the connecting path 51a with the other side surface 51a3. Let t1a be the narrowest width of the connecting path 51a at all points on the center line 51a1. In other words, width t1a is the width of the narrowest portion of the connecting path 51a.

[0080] The sum of the widths of the narrowest portions of at least one connection path included in the connection portion 51 is t1. Figure 8 In the illustrated structure, since the number of the connecting path 51 a included in the connecting portion 51 is one, the sum of the widths t1 is equal to the width t1 a ( t1 = t1 a ).

[0081] exist Figure 8 In the cross section shown, the arc-shaped boundary between the inner circumference of the connecting portion 51 and the outer circumference of the annular portion 50 is hereinafter referred to as the joint boundary 51b. The circumferential width of the joint boundary 51b, i.e., the length t2 of the joint boundary 51b along the arc, corresponds to the length of the arc of a circle with a radius Rmin centered on the axis O that overlaps with the connecting portion 51. The radius Rmin is the minimum radius of the connecting portion 51 centered on the axis O.

[0082] The sum t1 of the widths of the narrowest portions of each of at least one connection path included in the connection portion 51 is shorter than the length t2 of the joint boundary 51 b ( t1 < t2 ).

[0083] Here, Figure 8 The outer peripheral portion of the rotor 20 shown has a non-circular shape in a cross section perpendicular to the axial direction. The outer peripheral surface of each of the first core portion 41 and the second core portion 42 is formed into an arc shape centered at a position different from the axis of the rotor 20. When the radius of the circumscribed circle circumscribed to the rotor core 21 is set to r1, the radius of the outer peripheral surface of the first core portion 41 is set to r2, and the radius of the outer peripheral surface of the second core portion 42 is set to r3, the relationship r1>r2=r3 is satisfied. By making the rotor 20 have such a shape, the cogging torque and torque ripple are reduced. However, the rotor 20 of this embodiment can also be Figure 1 The rotor 20 shown in FIG. 1 and FIG. 2 similarly has a true circular shape in a cross section perpendicular to the axial direction.

[0084] Figure 9 It is shown in Figure 1 The maximum stress generated in the connection part of the rotor with the structure shown in FIG. Figure 8 The graph shows the maximum stress generated in the connection part of the rotor with the structure shown in FIG. Figure 8 In the rotor 20 of the structure shown, the maximum stress generated in the connection portion 51 during rotation is normalized to a stress [pu] of 1.

[0085] like Figure 9 As shown, in Figure 8 In the rotor 20 of the structure shown in FIG. 1 , when the maximum stress generated in the connection portion 51 during rotation is set to 1, Figure 1 In the rotor 20 of the structure shown, the maximum stress generated in the connection portion 51 during rotation is approximately 2.0. Therefore, it can be seen that Figure 8 In the structure shown, Figure 1 Compared with the structure shown, the maximum stress generated in the connection portion 51 can be reduced, and stress concentration can be alleviated.

[0086] Reducing the circumferential width of the connecting portion 51 increases the magnetic resistance of the connecting portion 51, thereby reducing the circumferential leakage flux Φ2. However, when the rotor 20 rotates, significant stress is generated at the junction 51b between the annular portion 50 and the connecting portion 51, making it difficult to reduce the circumferential width of the junction 51b.

[0087] exist Figure 8 In the structure of the present embodiment shown, the length t2 of the joint boundary 51b is longer than the sum t1 of the widths of the narrowest portions of each of at least one connection path of the connection portion 51. As a result, the circumferential width of the joint boundary 51b between the annular portion 50 and the connection portion 51 can be increased, thereby alleviating stress concentration at the joint boundary 51b. Figure 8 The structure of the present embodiment shown can improve the strength of the rotor 20 .

[0088] On the other hand, the circumferential width of the connecting portion 51 can be narrowed in the portion away from the joint boundary 51b of the connecting portion 51. As a result, the magnetic resistance of the connecting portion 51 can be increased, and thus the circumferential leakage flux Φ2 can be reduced. Figure 8 The structure of this embodiment shown in FIG. Figure 1 and Figure 6 Compared with the rotating electrical machine 100 serving as a premise of the present embodiment as shown, the effective magnetic flux Φ1 can be further increased, and the torque of the rotating electrical machine can be further improved.

[0089] The amount of magnetic flux passing through a magnetic circuit is determined by the narrowest width of the series of paths within that circuit. Specifically, the narrowest portion of the connecting path 51a experiences magnetic flux density saturation, resulting in a low magnetic permeability and, therefore, a difficulty in magnetic flux passing through it. Therefore, to reduce the amount of magnetic flux passing through the connecting portion 51, it is desirable to make the width of the connecting path 51a as narrow as possible.

[0090] On the other hand, in the rotor core 21, the structurally critical section related to strength is the arcuate joint boundary 51b between the outer periphery of the annular portion 50 and the connecting portion 51. Therefore, to improve the strength of the rotor core 21, it is preferable to make the length of the joint boundary 51b as long as possible.

[0091] In summary, by making the length of the joint boundary 51b as long as possible to improve strength, and by narrowing the width of the narrowest portion of the connection path 51a to reduce magnetic flux passing through the connection portion 51, strength can be improved and magnetic flux leakage can be reduced. Therefore, the sum of the widths t1 of the narrowest portion of each of at least one connection path 51a is at least shorter than the length t2 of the joint boundary 51b.

[0092] Furthermore, it is desirable that the width t1a of the narrowest portion of each connecting path 51a is greater than or equal to the thickness of the electromagnetic steel sheets constituting the rotor core 21. Furthermore, when the number of magnetic poles is p, the length t2 of the joint boundary 51b can be extended to a length obtained by dividing the length of a circle having a radius of Rmin by p / 2.

[0093] By comparing the sum t1 of the narrowest widths of each of at least one connecting path 51a with the length t2 of the joint boundary 51b, a structure capable of reducing the circumferential magnetic leakage flux Φ2 and alleviating stress concentration at the joint boundary 51b can be achieved.

[0094] That is, according to Figure 8 The structure of the present embodiment shown can achieve both improvement in the torque of the rotating electrical machine and improvement in the strength of the rotor 20 .

[0095] Figure 10 : is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the third comparative example of the present embodiment perpendicularly to the axial direction. Figure 10 As shown, in the rotor 20 of the third comparative example, the circumferential width of the connection portion 51 increases from the inner peripheral side toward the outer peripheral side.

[0096] Figure 11 It shows that Figure 8 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 10 The vertical axis of the graph represents the torque obtained by the rotating electric machine having the rotor of the structure shown in FIG. Figure 8 The torque obtained by the rotating electric machine of the rotor 20 having the structure shown is normalized to 1 torque [pu].

[0097] like Figure 11 As shown, in the Figure 8 When the torque obtained by the rotating electric machine of the rotor 20 of the structure shown is set to 1, Figure 10 The torque obtained by the rotating motor with the rotor of the structure shown is 0.96. Figure 8 In the rotating electrical machine of this embodiment having the rotor 20 of the structure shown in FIG. Figure 10 Compared with the rotating electrical machine of the third comparative example, the rotor 20 having the structure shown can obtain a higher average torque.

[0098] Figure 12 This is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to Modification 1-1 of the present embodiment perpendicularly to the axial direction. Figure 13 It is shown enlarged Figure 12 A part of the diagram. Figure 12 and Figure 13 As shown, the annular portion 50 of this modified example has a plurality of protrusions 52. The protrusions 52 are formed on the inner circumferential surface of the annular portion 50 and protrude inward. The protrusions 52 each contact the outer circumferential surface of the shaft 23 inserted into the annular portion 50 and are flattened by the shaft 23. The shaft 23 has a true circular cross-section.

[0099] also, Figure 12 and Figure 13 The shapes of the plurality of protrusions 52 shown are those before being flattened by the shaft 23 inserted into the annular portion 50. Before the shaft 23 is inserted into the annular portion 50, each of the plurality of protrusions 52 has, for example, a quadrilateral cross-sectional shape. However, the shapes of the plurality of protrusions 52 may be any other shapes.

[0100] The plurality of protrusions 52 are arranged at positions offset from at least the joint boundary 51b in the circumferential direction of the rotor 20. That is, when viewed in the radial direction of the rotor 20, the plurality of protrusions 52 are arranged so as not to overlap with any of the plurality of joint boundaries 51b.

[0101] The annular portion 50 has a plurality of protrusion groups 53, each of which has at least one protrusion 52. Figure 12 and Figure 13In the structure shown, each of the plurality of protrusion groups 53 has two protrusions 52. The plurality of protrusion groups 53 are arranged in the circumferential direction. When the number of magnetic poles of the rotor 20 is set to p, the number of protrusion groups 53 is p / 2. That is, the number of protrusion groups 53 is the same as the number of connecting portions 51. The plurality of protrusion groups 53 are respectively arranged between two connecting portions 51 adjacent to each other in the circumferential direction. When the angle formed by the center portion of the protrusion group 53 in the circumferential direction and the center portion of the joint boundary 51b in the circumferential direction is set to β, β>0. The plurality of protrusion groups 53 may not necessarily be arranged at equal intervals.

[0102] For example, when the number of pole pairs of the rotor 20 is P (P = 2 × p), the annular portion 50 includes one protrusion group 53 for every 360 / P degrees around the axis O of the rotor 20. In other words, the annular portion 50 includes N protrusions 52 for every 360 / P degrees around the axis O of the rotor 20. Here, N is an integer greater than or equal to 1.

[0103] When the shaft 23 is inserted into the annular portion 50 during the manufacturing process of the rotor 20, the annular portion 50 is subjected to stress from the shaft 23. Furthermore, when the rotor 20 rotates, greater stress is generated at the joint boundary 51b than at other parts. Therefore, when the rotor 20 rotates, there is a possibility that stress exceeding the yield point will be generated at the joint boundary 51b.

[0104] In contrast, in the annular portion 50 of this modified example, the protrusion 52, which is subject to stress from the shaft 23, is positioned offset from the joint boundary 51b. This reduces the stress from the shaft 23 on the joint boundary 51b, thereby alleviating stress concentration on the joint boundary 51b. Consequently, the stress generated at the joint boundary 51b can be reduced below the yield point, thereby improving the strength of the rotor 20.

[0105] Furthermore, in this variation, since multiple protrusions 52 are provided on the inner circumferential surface of the annular portion 50, stress applied to the shaft 23 can be concentrated on each of the multiple protrusions 52. Consequently, the radial thickness of the annular portion 50 can be reduced in the portion where the protrusions 52 are not formed. Consequently, the circumferential leakage magnetic flux Φ2 can be further reduced, while the effective magnetic flux Φ1 can be further increased. Consequently, this variation can further improve the torque of the rotating electrical machine.

[0106] Furthermore, in this modified example, the interference tolerance required when press-fitting the shaft 23 into the annular portion 50 can be relaxed.

[0107] Figure 14 1 is a cross-sectional view showing a structure obtained by cutting the shaft of the rotating electrical machine according to the modification 1-2 of the present embodiment perpendicularly to the axial direction. Figure 14As shown, a plurality of protrusions 24 are formed on the outer peripheral surface of the shaft 23. The plurality of protrusions 24 protrude from the outer peripheral surface of the shaft 23 and are connected to the annular portion 50 (at Figure 14 The inner peripheral surface of the annular portion 50 has, for example, a perfect circular cross-sectional shape.

[0108] Specifically, while in Modification 1-1, protrusions 52 are formed on the inner circumferential surface of annular portion 50, in this Modification, protrusions 24 are formed on the outer circumferential surface of shaft 23. Desirably, the plurality of protrusions 24 are arranged at positions offset from each of the plurality of joint boundaries 51b in the circumferential direction of rotor 20. This Modification also achieves the same effects as Modification 1-1.

[0109] As described above, the rotating electrical machine of this embodiment includes: a stator 10; and a rotor 20 rotatably disposed on the inner circumference of the stator 10. The rotor 20 includes: a rotor core 21; a plurality of permanent magnets 22 disposed on the rotor core 21; and a shaft 23 fixed to the center of the rotor core 21 and extending in the axial direction of the rotor 20. The rotor core 21 is formed with a plurality of holes 30 arranged circumferentially of the rotor 20. The plurality of holes 30 include a plurality of first holes 31 and a plurality of second holes 32. The plurality of permanent magnets 22 are inserted only into each of the plurality of first holes 31 of the plurality of holes 30. The plurality of first holes 31 and the plurality of second holes 32 are arranged alternately in the circumferential direction. The rotor core 21 includes a plurality of core portions 40 circumferentially arranged with each of the plurality of second holes 32 interposed therebetween. The plurality of permanent magnets 22 are magnetized in such a manner that the pole faces facing each other in the circumferential direction become different poles. The plurality of core parts 40 respectively include a first core part 41 located on the pole face side of one side of each of the plurality of permanent magnets 22 and a second core part 42 located on the pole face side of the other side of each of the plurality of permanent magnets 22. The rotor core 21 has a first rotor core in at least a portion of the axial direction. The first rotor core has an annular part 50 and a plurality of connecting parts 51. The annular part 50 is provided at a position closer to the inner circumference than the plurality of core parts 40 and is configured to allow the shaft 23 to be inserted. The plurality of connecting parts 51 respectively connect the annular part 50 with the first core part 41 of each of the plurality of core parts 40. The plurality of connecting parts 51 respectively include at least one connecting path 51a. The sum t1 of the width of the narrowest part in each of the at least one connecting path 51a is shorter than the length t2 of the arc-shaped joint boundary 51b between the annular part 50 and each of the plurality of connecting parts 51. Here, in Figure 8 The rotor core 21 shown in cross section in FIG is an example of a first rotor core. The annular portion 50 is an example of a first annular portion. The plurality of connecting portions 51 are an example of a plurality of first connecting portions.

[0110] According to this configuration, the plurality of first core portions 41 magnetized to the same polarity are connected to each other via the annular portion 50 and the plurality of connecting portions 51. This reduces the circumferential leakage flux Φ2 passing through the annular portion 50 and the plurality of connecting portions 51. Consequently, the torque output of the rotating electrical machine can be improved.

[0111] Furthermore, this configuration allows for a longer length of the joint boundary 51b between the annular portion 50 and the coupling portion 51, thereby alleviating stress concentration at the joint boundary 51b. Consequently, the strength of the rotor 20 can be enhanced.

[0112] Furthermore, this configuration allows the circumferential width of the connection portion 51 to be narrowed in the portion away from the joint boundary 51b, thereby increasing the magnetic resistance of the connection portion 51. Consequently, the circumferential leakage flux Φ2 can be reduced, further improving the torque output of the rotating electrical machine.

[0113] In the rotating electrical machine of this embodiment, the annular portion 50 includes a protrusion 52 formed on its inner circumferential surface and in contact with the outer circumferential surface of the shaft 23. This configuration concentrates stress from the shaft 23 on the protrusion 52, allowing the radial thickness of the annular portion 50 to be reduced. Consequently, the circumferential magnetic flux leakage Φ2 can be further reduced, further improving the torque of the rotating electrical machine. Furthermore, this configuration can alleviate the interference tolerance required when press-fitting the shaft 23 into the annular portion 50.

[0114] In the rotating electrical machine of this embodiment, the protrusion 52 is arranged at a position offset in the circumferential direction from each of the plurality of connecting portions 51. This configuration reduces the stress applied to the joint boundary 51b between the annular portion 50 and the connecting portion 51 by the shaft 23, and the stress generated at the joint boundary 51b can be reduced to below the yield point, thereby improving the strength of the rotor 20.

[0115] In the rotating electrical machine of this embodiment, the annular portion 50 has multiple protrusion groups 53 in a cross-section perpendicular to the axial direction. Each of these protrusion groups 53 includes at least one protrusion 52 formed on the inner circumferential surface of the annular portion 50 and in contact with the outer circumferential surface of the shaft 23. Each of the multiple protrusion groups 53 is circumferentially disposed between adjacent two of the multiple connecting portions 51. This structure reduces stress from the shaft 23 at the junction 51b between the annular portion 50 and the connecting portion 51, allowing stress generated at the junction 51b to be kept below the yield point. Consequently, the strength of the rotor 20 can be improved.

[0116] In the rotating electrical machine of this embodiment, shaft 23 has protrusions 24 formed on its outer circumferential surface and contacting the inner circumferential surface of annular portion 50. This structure can alleviate the interference tolerance required when press-fitting shaft 23 into annular portion 50.

[0117] In the rotating electrical machine of this embodiment, the circumferential width of the second hole 32 increases from the outer circumference toward the inner circumference. This configuration reduces the circumferential leakage flux Φ2 on the inner circumference of the rotor 20, thereby suppressing torque reduction of the rotating electrical machine.

[0118] Implementation method 2.

[0119] The rotating electrical machine according to the second embodiment will be described. Figure 15 This is a cross-sectional view showing the structure of the rotor of the rotating electrical machine according to this embodiment, cut perpendicularly to the axial direction. Although not shown, the stator 10 is provided on the outer circumference of the rotor 20 with a gap 15 therebetween. Components having the same functions and effects as those in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0120] like Figure 15 As shown, the multiple connecting portions 51 each have multiple connecting paths 51a and 51c arranged in parallel with each other. The multiple connecting paths 51a and 51c each constitute multiple paths of the magnetic circuit formed in one connecting portion 51. In a cross-section perpendicular to the axial direction, a non-magnetic hole 54 is formed in each of the multiple connecting portions 51. The non-magnetic hole 54 is formed between two adjacent connecting paths 51a and 51c. The cross-sectional shape of the non-magnetic hole 54 can also be any shape. The interior of the non-magnetic hole 54 can be either empty or filled with non-magnetic material.

[0121] The width t1a of the connecting path 51a is constant in the radial direction. That is, the width of the narrowest portion of the connecting path 51a is t1a. Similarly, the width t1c of the connecting path 51c is constant in the radial direction. That is, the width of the narrowest portion of the connecting path 51c is t1c. The sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is the sum of width t1a and width t1c (t1 = t1a + t1c). The sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is shorter than the length t2 of the joint boundary 51b (t1 < t2).

[0122] Figure 16 : is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 2-1 of the present embodiment perpendicularly to the axial direction. Figure 16 As shown, the two connecting paths 51a and 51c of the connecting portion 51 extend parallel to each other. The non-magnetic hole 54 extends linearly along the extending direction of the connecting portion 51. In this modified example, the sum of the widths t1 of the narrowest portions of each of the multiple connecting paths 51a and 51c is also shorter than the length t2 of the joint boundary 51b.

[0123] As already explained, according to the first embodiment, both improved torque of the rotating electrical machine and increased strength of the rotor 20 can be achieved. However, if the rotating electrical machine is used in a higher-speed rotation range, greater stress will be generated at the joint boundary 51b, and therefore the circumferential width of the connecting portion 51 will need to be further increased. However, increasing the circumferential width of the connecting portion 51 will increase the circumferential magnetic flux leakage Φ2. Therefore, the inventors of the present application have devised a method of providing nonmagnetic holes 54 in the connecting portion 51 to suppress the increase in circumferential magnetic flux leakage Φ2 and increase the circumferential width of the connecting portion 51.

[0124] Figure 17 It shows that Figure 16 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 10 The vertical axis of the graph represents the torque obtained by the rotating electric machine having the rotor of the structure shown in FIG. Figure 16 The torque obtained by the rotating electric machine of the rotor 20 of the structure shown is normalized to 1 torque [pu]. Figure 16 The rotor 20 shown has the same structure as the one shown in FIG. 1 except that a non-magnetic hole 54 is formed in the connecting portion 51. Figure 10 The rotor 20 shown has the same structure.

[0125] like Figure 17 As shown, in the Figure 16 When the torque obtained by the rotating electric machine of the rotor 20 of the structure shown is set to 1, Figure 10 The torque obtained by the rotating motor of the rotor 20 of the structure shown is about 0.98. Figure 16 In the rotating electrical machine of the modified example 2-1 of the rotor 20 having the structure shown in FIG. Figure 10 Compared with the rotating electrical machine of the third comparative example, the rotor 20 having the structure shown can obtain a higher average torque.

[0126] Figure 18 2 is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 2-2 of the present embodiment perpendicularly to the axial direction. Figure 18 As shown, the rotor 20 of this modified example is Figure 16 The difference in the structure shown is that, in a cross section perpendicular to the axial direction, a portion of the non-magnetic hole 54 has a circular fastening hole 55. The fastening hole 55 is configured to allow a fastening member such as a bolt to pass axially therethrough. The non-magnetic hole 54 extends in the direction in which the connecting portion 51 extends.

[0127] In a cross-section perpendicular to the axial direction, the connecting portion 51 has a pair of edges 54a and 54b that oppose each other, sandwiching the non-magnetic hole 54. Each edge 54a and edge 54b are formed linearly along the direction in which the non-magnetic hole 54 extends. In a cross-section perpendicular to the axial direction, a portion of edge 54a is formed with a recessed portion 54c that is recessed into an arc shape. In this cross-section, a portion of edge 54b is formed with a recessed portion 54d that is concentric with recess 54c and has the same radius as recess 54c. Recesses 54c and 54d each constitute a portion of the edge of the circular fastening connecting hole 55.

[0128] In the cross section perpendicular to the axial direction, the connecting portion 51 includes a first auxiliary connecting portion 56 disposed on the edge 54a side of the non-magnetic hole 54 and a second auxiliary connecting portion 57 disposed on the edge 54b side of the non-magnetic hole 54. The first auxiliary connecting portion 56 corresponds to Figure 16 The second auxiliary connection portion 57 corresponds to the connection path 51a of the structure shown. Figure 16 The connection path 51c of the structure shown. The first auxiliary connection part 56 and the second auxiliary connection part 57 extend from the annular part 50 to the first core part 41 respectively along the extension direction of the non-magnetic hole 54, that is, the extension direction of the connection part 51. A part of the first auxiliary connection part 56 is bent outward along the recess 54c. A part of the second auxiliary connection part 57 is bent outward along the recess 54d. That is, a part of the first auxiliary connection part 56 and a part of the second auxiliary connection part 57 are bent to both sides while clamping the fastening connection hole 55 in a manner that bypasses the fastening connection hole 55. As a result, the circumferential width of each of the first auxiliary connection part 56 and the second auxiliary connection part 57 is constant in the radial direction of the rotor 20. Therefore, the magnetic resistance of the magnetic circuit of the circumferential leakage magnetic flux Φ2 is constant with respect to the magnetic resistance of the magnetic circuit of the circumferential leakage magnetic flux Φ2. Figure 16 The structure shown in FIG. 1 is almost unchanged. In this modified example, the same Figure 15 and Figure 16 The same effect as the structure shown.

[0129] Figure 19 : is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 2-3 of the present embodiment perpendicularly to the axial direction. Figure 19 As shown, the rotor 20 of this modified example is Figure 18 The rotor 20 of the illustrated modification 2-2 differs in that the rotor core 21 includes a plurality of connecting portions 58 in place of the plurality of connecting portions 51. The plurality of connecting portions 58 respectively connect the annular portion 50 to the plurality of second core portions 42. That is, in this modification, in a cross section perpendicular to the axial direction, the plurality of second core portions 42 are magnetically connected via the annular portion 50 and the plurality of connecting portions 58.

[0130] On the other hand, each of the plurality of connection portions 58 is not directly connected to the plurality of first core portions 41. In a cross section perpendicular to the axial direction, the first core portion 41 is connected to the connection portion 58 and the annular portion 50 only via the adjacent second core portion 42 with the permanent magnet 22 therebetween.

[0131] In the cross section perpendicular to the axis, Figure 18 Similarly, the connecting portion 51 of Modification 2-2 shown here has a non-magnetic hole 59 formed in the connecting portion 58, and a portion of this non-magnetic hole 59 has a circular fastening hole 60. The relative position of the fastening hole 60 of this modification with respect to the rotor core 21 differs from the relative position of the fastening hole 55 of Modification 2-2 with respect to the rotor core 21. The fastening hole 60 of this modification and the fastening hole 55 of Modification 2-2 are arranged at positions symmetrical to each other with respect to the permanent magnet 22 as the center.

[0132] In addition, similarly to the connection portion 51 of the modification 2-2, the connection portion 58 includes the edge portion 54a, the edge portion 54b, the recessed portion 54c, the recessed portion 54d, the first auxiliary connection portion 56, and the second auxiliary connection portion 57. The circumferential width of each of the first auxiliary connection portion 56 and the second auxiliary connection portion 57 is constant in the radial direction of the rotor 20. This modification can also obtain the same Figure 15 and Figure 16 The same effect as the structure shown.

[0133] Figure 20 : is an exploded perspective view showing the structure of the rotor of the rotating electrical machine according to the modification 2-4 of the present embodiment. Figure 20 As shown, the rotor 20 of this modified example includes: a rotor core 21, in which a first rotor core 21-1 and a second rotor core 21-2 are arranged overlapping each other in the axial direction; and a pair of end plates 70, 80, which are arranged on the outside of the rotor core 21 in the axial direction.

[0134] The first rotor core 21-1 has Figure 18 The second rotor core 21-2 has the same cross-sectional shape as the structure shown. Figure 19 The first rotor core 21-1 and the second rotor core 21-2 have the same cross-sectional shape as the structure shown. The first rotor core 21-1 and the second rotor core 21-2 are stacked in the axial direction of the rotor 20, with their core portions 40 axially overlapping and their fastening holes 55 and fastening holes 60 not axially overlapping. The first rotor core 21-1 and the second rotor core 21-2 are axially sandwiched between a pair of end plates 70 and 80. One axial end of the connecting portion 51 of the first rotor core 21-1 is connected to the end plate 70. One axial end of the connecting portion 58 of the second rotor core 21-2 is connected to the end plate 80.

[0135] Each end plate 70 and end plate 80 has a disc-like shape. A plurality of fastening holes 71 are formed in the end plate 70 and arranged circumferentially. The number of fastening holes 71 is equal to the sum of the number of fastening holes 55 formed in the first rotor core 21-1 and the number of fastening holes 60 formed in the second rotor core 21-2.

[0136] A plurality of fastening holes 81 arranged in the circumferential direction are formed in the end plate 80. The number of the fastening holes 81 is equal to the number of the fastening holes 71. The fastening holes 71 and the fastening holes 81 are each configured to receive a fastening member 82 such as a bolt.

[0137] The end plate 70, the first rotor core 21-1, the second rotor core 21-2 and the end plate 80 are fastened together by a plurality of fastening members 82. Figure 20 In FIG, only one fastening member 82 is shown.

[0138] A fastening member 82 is inserted into the fastening hole 71 of the end plate 70, the fastening hole 55 of the first rotor core 21-1, and the fastening hole 81 of the end plate 80, thereby fastening the end plate 70, the connecting portion 51 of the first rotor core 21-1, and the end plate 80. This fastening member 82 is not inserted into the fastening hole 60 of the second rotor core 21-2.

[0139] Another fastening member 82 is inserted into the fastening hole 71 of the end plate 70, the fastening hole 60 of the second rotor core 21-2, and the fastening hole 81 of the end plate 80, thereby fastening the end plate 70, the connecting portion 58 of the second rotor core 21-2, and the end plate 80. This fastening member 82 is not inserted into the fastening hole 55 of the first rotor core 21-1.

[0140] The end plate 70 , the first rotor core 21 - 1 , the second rotor core 21 - 2 , and the end plate 80 are fastened together using a plurality of fastening members 82 , thereby firmly fixing the rotor 20 in the axial direction.

[0141] exist Figure 20 In the illustrated structure, one first rotor core 21 - 1 and one second rotor core 21 - 2 are stacked in the axial direction. However, one or more first rotor cores 21 - 1 and one or more second rotor cores 21 - 2 may be alternately stacked in the axial direction.

[0142] In this modification, considering the axial structure, all first core portions 41 and all second core portions 42 are connected to the connecting portion 51, the connecting portion 58, and the annular portion 50. This allows the rotor core 21 to be integrated, thereby improving the overall strength of the rotor 20.

[0143] On the other hand, in a cross section perpendicular to the axial direction, only one of the first core portion 41 and the second core portion 42 is connected to the connecting portion 51 or the connecting portion 58. Therefore, the circumferential magnetic leakage flux Φ2 does not increase significantly. Therefore, according to this modified example, it is possible to suppress a decrease in the torque of the rotating electrical machine and improve the strength of the rotor 20.

[0144] Figure 21 : is an exploded perspective view showing the structure of the rotor of the rotating electrical machine according to the modification 2-5 of the present embodiment. Figure 21 As shown, the rotor core 21 of the rotor 20 of this modified example has a structure in which a first rotor core 21-1, a third rotor core 21-3, and a second rotor core 21-2 are arranged one above the other in the axial direction. The end plate 70, the first rotor core 21-1, the third rotor core 21-3, the second rotor core 21-2, and the end plate 80 are stacked in this order in the axial direction.

[0145] The first rotor core 21-1 has Figure 18 The second rotor core 21-2 has the same cross-sectional shape as the structure shown. Figure 19 The third rotor core 21-3 has the same cross-sectional shape as the structure shown. Similar to the first and second rotor cores 21-1 and 21-2, the third rotor core 21-3 includes multiple core portions 40 and an annular portion 50. The third rotor core 21-3 lacks the connecting portion 51 and the connecting portion 58. Therefore, in a cross-section perpendicular to the axial direction, the multiple core portions 40 of the third rotor core 21-3 are spaced apart from the annular portion 50. The first, third, and second rotor cores 21-1, 21-3, and 21-2 are axially sandwiched by a pair of end plates 70 and 80.

[0146] The end plate 70, the first rotor core 21-1, the third rotor core 21-3, the second rotor core 21-2 and the end plate 80 are fastened together using a plurality of fastening members 82. Figure 21 Only one fastening member 82 is shown.

[0147] A fastening member 82 is inserted into the fastening hole 71 of the end plate 70, the fastening hole 55 of the first rotor core 21-1, and the fastening hole 81 of the end plate 80, thereby fastening the end plate 70, the first rotor core 21-1, and the end plate 80. This fastening member 82 is not inserted into the fastening hole 60 of the second rotor core 21-2. No fastening hole for inserting this fastening member 82 is formed in the third rotor core 21-3.

[0148] Another fastening member 82 is inserted into the fastening hole 71 of the end plate 70, the fastening hole 60 of the second rotor core 21-2, and the fastening hole 81 of the end plate 80, thereby fastening the end plate 70, the second rotor core 21-2, and the end plate 80. This fastening member 82 is not inserted into the fastening hole 55 of the first rotor core 21-1. No fastening hole for inserting this fastening member 82 is formed in the third rotor core 21-3.

[0149] By fastening and coupling using the plurality of fastening members 82 , the end plate 70 , the first rotor core 21 - 1 , the third rotor core 21 - 3 , the second rotor core 21 - 2 , and the end plate 80 are firmly fixed in the axial direction.

[0150] exist Figure 21 In the illustrated structure, one first rotor core 21-1, one third rotor core 21-3, and one second rotor core 21-2 are stacked in the axial direction. However, one or more first rotor cores 21-1, one or more third rotor cores 21-3, and one or more second rotor cores 21-2 may be stacked in sequence in the axial direction.

[0151] Desirably, the third rotor core 21-3 is disposed between the axially adjacent first and second rotor cores 21-1, 21-2. This allows the connection portion 51 of the first rotor core 21-1 and the connection portion 58 of the second rotor core 21-2 to be separated in the axial direction, sandwiching the third rotor core 21-3 between them. This reduces axial magnetic flux leakage between the first and second rotor cores 21-1, 21-2.

[0152] In this modification, considering the axial structure, all first core portions 41 and all second core portions 42 are connected to the connecting portion 51, the connecting portion 58, and the annular portion 50. This allows the rotor core 21 to be integrated, thereby improving the overall strength of the rotor 20.

[0153] In the first rotor core 21-1 and the second rotor core 21-2, in a cross section perpendicular to the axial direction, only one of the first core portion 41 and the second core portion 42 is connected to the connecting portion 51 or the connecting portion 58. Furthermore, in the third rotor core 21-3, in a cross section perpendicular to the axial direction, both the first core portion 41 and the second core portion 42 are spaced apart from the annular portion 50. Consequently, circumferential magnetic leakage flux Φ2 can be reduced.

[0154] Therefore, according to this modification, it is possible to improve the strength of the rotor 20 while suppressing a reduction in the torque of the rotating electrical machine.

[0155] Figure 22: is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 2-6 of the present embodiment perpendicularly to the axial direction. Figure 22 As shown, the plurality of connection parts 51 each have a plurality of connection paths 51a, 51c. In a cross section perpendicular to the axial direction, a non-magnetic hole 54 is formed in each of the plurality of connection parts 51. The non-magnetic hole 54 is formed between two adjacent connection paths 51a, 51c.

[0156] The width t1a of the connecting path 51a is constant in the radial direction. That is, the width of the narrowest portion of the connecting path 51a is t1a. Similarly, the width t1c of the connecting path 51c is constant in the radial direction. That is, the width of the narrowest portion of the connecting path 51c is t1c. The sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is the sum of width t1a and width t1c (t1 = t1a + t1c). The sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is shorter than the length t2 of the joint boundary 51b (t1 < t2).

[0157] Figure 23 : is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 2-7 of the present embodiment perpendicularly to the axial direction. Figure 23 As shown, the plurality of connection parts 51 each have a plurality of connection paths 51a, 51c. In a cross section perpendicular to the axial direction, a non-magnetic hole 54 is formed in each of the plurality of connection parts 51. The non-magnetic hole 54 is formed between two adjacent connection paths 51a, 51c.

[0158] The width of the narrowest portion of connecting path 51a is t1a. The width of the narrowest portion of connecting path 51c is t1c. The sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is the sum of width t1a and width t1c (t1 = t1a + t1c). In this modified example, the sum t1 of the widths of the narrowest portions of each of the multiple connecting paths 51a and 51c is also shorter than the length t2 of the joint boundary 51b (t1 < t2).

[0159] Here, in a cross section perpendicular to the axial direction, an inscribed circle centered on the axis O of the rotor 20 and inscribed within the plurality of permanent magnets 22 is referred to as circle C1. In this modification, the non-magnetic holes 54 are positioned on the outer circumference side of circle C1. For example, the non-magnetic holes 54 are not located on the inner circumference side of circle C1, but only on the outer circumference side of circle C1.

[0160] In this modification, the circumferential width of the junction boundary 51b between the connecting portion 51 and the annular portion 50 can be increased, thereby alleviating stress concentration at the junction boundary 51b. Furthermore, the strength of the connecting portion 51 can be increased at a position further inward than the inner circumferential end of the permanent magnet 22.

[0161] Figure 24 It shows that Figure 22 The torque obtained by the rotating motor having the rotor of the structure shown is the same as that obtained by the rotating motor having the Figure 23 The vertical axis of the graph represents the torque obtained by the rotating electric machine having the rotor of the structure shown in FIG. Figure 22 The torque obtained by the rotating electric machine having the rotor of the structure shown is normalized to 1 torque [pu].

[0162] like Figure 24 As shown, in the Figure 22 When the torque obtained by the rotating electric machine of the rotor of the structure shown is set to 1, Figure 23 The torque obtained by the rotating motor of the rotor of the structure shown is about 0.995. Therefore, it can be known that: Figure 23 The rotating electrical machine of this modified example can obtain Figure 22 The average torque of the rotating electrical machine is equivalent to that of the modified examples 2 to 6 shown. That is, according to this modified example, the strength of the rotor 20 can be improved while suppressing a decrease in the torque of the rotating electrical machine.

[0163] As described above, the rotating electrical machine of this embodiment includes: a stator 10; and a rotor 20 rotatably disposed on the inner circumference of the stator 10. The rotor 20 includes: a rotor core 21; a plurality of permanent magnets 22 disposed on the rotor core 21; and a shaft 23 fixed to the center of the rotor core 21 and extending in the axial direction of the rotor 20. The rotor core 21 is formed with a plurality of holes 30 arranged circumferentially of the rotor 20. The plurality of holes 30 include a plurality of first holes 31 and a plurality of second holes 32. The plurality of permanent magnets 22 are inserted only into each of the plurality of first holes 31 of the plurality of holes 30. The plurality of first holes 31 and the plurality of second holes 32 are arranged alternately in the circumferential direction. The rotor core 21 includes a plurality of core portions 40 circumferentially arranged with each of the plurality of second holes 32 interposed therebetween. The plurality of permanent magnets 22 are magnetized so that their circumferentially facing magnetic pole faces have opposite polarities. The plurality of core sections 40 each include a first core section 41 located on one magnetic pole face side of each of the plurality of permanent magnets 22, and a second core section 42 located on the other magnetic pole face side of each of the plurality of permanent magnets 22. The rotor core 21 includes a first rotor core in at least a portion of its axial direction. The first rotor core includes an annular portion 50 and a plurality of connecting portions 51. The annular portion 50 is positioned closer to the inner circumference than the plurality of core sections 40 and is configured to receive the shaft 23. The plurality of connecting portions 51 connect the annular portion 50 to the first core section 41 of each of the plurality of core sections 40. The plurality of connecting portions 51 each include a plurality of connecting paths 51a, 51c. The sum of the widths (t1) of the narrowest portions of each of the plurality of connecting paths 51a, 51c is shorter than the length (t2) of the arc-shaped joining boundary 51b between the annular portion 50 and each of the plurality of connecting portions 51. A non-magnetic hole 54 is formed between two adjacent connection paths 51a and 51c among the plurality of connection paths 51a and 51c. Here, the annular portion 50 is an example of a first annular portion. The plurality of connection portions 51 are an example of a plurality of first connection portions.

[0164] With this configuration, the plurality of first core portions 41 magnetized to the same polarity are connected to each other via the annular portion 50 and the plurality of connecting portions 51. This reduces the circumferential leakage flux Φ2 passing through the annular portion 50 and the plurality of connecting portions 51. Consequently, with this configuration, the torque output of the rotating electrical machine can be improved.

[0165] Furthermore, this configuration, with the nonmagnetic holes 54 formed in the connection portion 51, can suppress the increase in circumferential leakage flux Φ2 passing through the connection portion 51, while expanding the circumferential width of the connection portion 51. Consequently, this configuration increases the effective magnetic flux Φ1, further improving the torque output of the rotating electrical machine. Furthermore, this configuration mitigates stress concentration in the connection portion 51, thereby improving the strength of the rotor 20.

[0166] In the rotating electrical machine of this embodiment, the nonmagnetic hole 54 has a circular fastening hole 55 in a cross section perpendicular to the axial direction, through which the fastening member 82 axially penetrates. This configuration allows the rotor 20 to be fastened in the axial direction using the fastening member 82, thereby improving the strength of the rotor 20.

[0167] In the rotating electrical machine of this embodiment, in a cross-section perpendicular to the axial direction, the non-magnetic hole 54 is positioned on the outer circumference side of a circle C1 centered on the axis O of the rotor 20 and inscribed within the plurality of permanent magnets 22. This configuration increases the circumferential width of the junction 51b between the connecting portion 51 and the annular portion 50, thereby alleviating stress concentration at the junction 51b and improving the strength of the rotor 20. Furthermore, this configuration improves the strength of the connecting portion 51 at a position further inward than the inner circumferential ends of the permanent magnets 22.

[0168] In the rotating electrical machine of this embodiment, the circumferential width of each of the plurality of coupling portions 51 is constant in the radial direction of the rotor 20. This configuration can suppress an increase in the circumferential magnetic flux leakage Φ2 while increasing the circumferential width of the coupling portions 51. Consequently, the torque of the rotating electrical machine can be increased, while also enhancing the strength of the rotor 20.

[0169] In the rotating electrical machine of this embodiment, the rotor 20 further includes an end plate 70 and an end plate 80 arranged axially outside the rotor core 21. The ends of the plurality of connecting portions 51 in the axial direction are connected to the end plate 70 or the end plate 80. With this configuration, the plurality of connecting portions 51 are each supported by the end plate 70 or the end plate 80, thereby improving the strength of the rotor 20.

[0170] In the rotating electrical machine of this embodiment, each of the plurality of coupling portions 51 is fastened to the end plate 70 or the end plate 80 by a fastening member 82 that passes through the non-magnetic hole 54. This configuration allows the rotor 20 to be fastened in the axial direction by the fastening member 82, thereby improving the strength of the rotor 20.

[0171] In the rotating electrical machine of this embodiment, the rotor core 21 further includes a second rotor core 21-2, arranged to overlap the first rotor core 21-1 in the axial direction. The second rotor core 21-2 includes an annular portion 50, which is positioned closer to the inner circumference than the plurality of core sections 40 and into which the shaft 23 is inserted, and a plurality of connecting portions 58, each connecting the annular portion 50 to the second core section 42 of the plurality of core sections 40. The annular portion 50 of the second rotor core 21-2 is an example of a second annular portion. The plurality of connecting portions 58 of the second rotor core 21-2 are an example of a plurality of second connecting portions.

[0172] According to this configuration, considering the axial structure, both the first core portion 41 and the second core portion 42 are connected to the connecting portion 51, the connecting portion 58, and the annular portion 50. This allows the rotor core 21 to be integrated, thereby improving the overall strength of the rotor 20.

[0173] In the rotating electrical machine of this embodiment, the rotor core 21 further includes a third rotor core 21-3, which is arranged to overlap the first rotor core 21-1 and the second rotor core 21-2 in the axial direction. The third rotor core 21-3 includes an annular portion 50, which is located closer to the inner circumference of the plurality of core sections 40 and into which the shaft 23 is inserted. In a cross section perpendicular to the axial direction, the annular portion 50 of the third rotor core 21-3 is spaced apart from either the first core section 41 or the second core section 42 of the plurality of core sections 40. Here, the annular portion 50 of the third rotor core 21-3 is an example of a third annular portion.

[0174] With this configuration, the annular portion 50 is spaced apart from the first core portion 41 and the second core portion 42 in the third rotor core 21-3, which is a portion of the rotor core 21 in the axial direction.

[0175] Implementation method 3.

[0176] The rotating electrical machine according to the third embodiment will be described. Figure 25 This is a cross-sectional view showing the structure of the rotor of the rotating electrical machine according to this embodiment, cut perpendicularly to the axial direction. Although not shown, the stator 10 is provided on the outer circumference of the rotor 20 with a gap 15 therebetween. Components having the same functions and effects as those in the first or second embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0177] like Figure 25 As shown, the plurality of connecting portions 51 connect the annular portion 50 and the plurality of first core portions 41. Each of the plurality of connecting portions 51 is formed separately from the annular portion 50 and the first core portion 41. Each of the plurality of connecting portions 51 has a structure that can be separated from either the annular portion 50 or the first core portion 41.

[0178] The plurality of connecting parts 51 are each formed of a non-magnetic material. Therefore, the circumferential leakage magnetic flux Φ2 passing through the connecting part 51 can be reduced. However, the plurality of connecting parts 51 may also be each formed of a magnetic material. Figure 8 Similarly to the structure shown, the sum of the widths of the narrowest portions of each of at least one connection path included in the connection portion 51 is shorter than the length of the joint boundary 51 b .

[0179] Each of the plurality of connecting portions 51 has an engaging recess 91 at one radial end portion for engaging with the annular portion 50. Furthermore, each of the plurality of connecting portions 51 has an engaging recess 92 at the other radial end portion for engaging with the first core portion 41. Each of the engaging recesses 91 and 92 has, for example, a T-shaped cross-section. Each of the engaging recesses 91 and 92 has a uniform cross-sectional shape along the axial direction of the rotor 20.

[0180] The annular portion 50 has a plurality of engaging protrusions 93 on its outer circumferential surface. Each of these engaging protrusions 93 is axially engaged with the engaging recesses 91 of the connecting portion 51. Each of the engaging protrusions 93 has a T-shaped cross-section that fits into the engaging recesses 91. Each of the engaging protrusions 93 has a uniform cross-sectional shape along the axial direction of the rotor 20.

[0181] Each of the plurality of first core portions 41 has an engagement protrusion 94 on its inner circumferential surface. The engagement protrusion 94 axially engages with the engagement recess 92 of each of the plurality of coupling portions 51. The engagement protrusion 94 has a T-shaped cross-section that fits into the engagement recess 92. The engagement protrusion 94 has a uniform cross-sectional shape along the axial direction of the rotor 20.

[0182] Each of the plurality of connecting parts 51 can be separated from the annular part 50 by being relatively offset in the axial direction with respect to the annular part 50. On the other hand, each of the plurality of connecting parts 51 is firmly fixed to the annular part 50 against a force acting in a plane perpendicular to the axial direction.

[0183] Furthermore, each of the plurality of connecting portions 51 can be separated from each of the plurality of first core portions 41 by being relatively offset in the axial direction relative to each of the plurality of first core portions 41. On the other hand, each of the plurality of connecting portions 51 is firmly fixed to each of the plurality of first core portions 41 against a force acting in a plane perpendicular to the axial direction.

[0184] Since the connection portion 51 can be separated from either the annular portion 50 or the first core portion 41 , the shapes of components of the rotor core 21 can be simplified, and the manufacturability of the rotor 20 can be improved.

[0185] Figure 26 : is a cross-sectional view showing a structure obtained by cutting the rotor of the rotating electrical machine according to the modification 3-1 of the present embodiment perpendicularly to the axial direction. Figure 26 As shown, the rotor 20 of this modified example is Figure 25 The illustrated rotor 20 is different in that the rotor core 21 includes a plurality of connection portions 58 instead of the plurality of connection portions 51 .

[0186] The plurality of connecting portions 58 connect the annular portion 50 and the plurality of second core portions 42. Each of the plurality of connecting portions 58 is formed separately from the annular portion 50 and the second core portion 42. Each of the plurality of connecting portions 58 has a structure that can be separated from either the annular portion 50 or the second core portion 42.

[0187] The plurality of connecting parts 58 are each formed of a non-magnetic material. Therefore, the circumferential leakage magnetic flux Φ2 passing through the connecting parts 58 can be reduced. However, the plurality of connecting parts 58 can also be formed of a magnetic material. Figure 8 Similarly to the illustrated structure, the sum of the widths of the narrowest portions of each of at least one connection path included in the connection portion 58 is shorter than the length of the joint boundary 58 b .

[0188] Similar to each of the plurality of connection portions 51, each of the plurality of connection portions 58 has an engagement recess 91 at one radial end portion and an engagement recess 92 at the other radial end portion. Each of the engagement recesses 91 and 92 has, for example, a T-shaped cross-sectional shape. Each of the engagement recesses 91 and 92 has a uniform cross-sectional shape along the axial direction of the rotor 20.

[0189] The annular portion 50 has a plurality of engaging protrusions 93 on its outer circumferential surface. Each of the engaging protrusions 93 is axially engaged with the engaging recesses 91 of the connecting portion 58. Each of the engaging protrusions 93 has a T-shaped cross-section that fits into the engaging recesses 91. Each of the engaging protrusions 93 has a uniform cross-sectional shape along the axial direction of the rotor 20.

[0190] Each of the plurality of second core portions 42 has an engagement protrusion 94 on its inner circumferential surface. The engagement protrusion 94 axially engages with the engagement recess 92 of each of the plurality of coupling portions 58. The engagement protrusion 94 has a T-shaped cross-section that fits into the engagement recess 92. The engagement protrusion 94 has a uniform cross-section along the axial direction of the rotor 20.

[0191] Each of the plurality of connecting portions 58 can be separated from the annular portion 50 by being relatively offset in the axial direction relative to the annular portion 50. On the other hand, each of the plurality of connecting portions 58 is firmly fixed to the annular portion 50 against a force acting in a plane perpendicular to the axial direction.

[0192] Furthermore, each of the plurality of connecting portions 58 can be separated from each of the plurality of second core portions 42 by being axially offset relative to each of the plurality of second core portions 42. On the other hand, each of the plurality of connecting portions 58 is firmly fixed to each of the plurality of second core portions 42 against a force acting in a plane perpendicular to the axial direction.

[0193] Figure 27: is an exploded perspective view showing the structure of the rotor of the rotating electrical machine according to the modified example 3-2 of the present embodiment. Figure 27 As shown, the rotor 20 of this modification includes a rotor core 21 in which a first rotor core 21 - 1 and a second rotor core 21 - 2 are arranged to overlap each other in the axial direction.

[0194] The first rotor core 21-1 has Figure 25 The second rotor core 21-2 has the same cross-sectional shape as the structure shown. Figure 26 The first rotor core 21 - 1 and the second rotor core 21 - 2 are stacked on each other in the axial direction of the rotor 20 so that their core portions 40 overlap each other in the axial direction.

[0195] exist Figure 25 In the illustrated structure, one first rotor core 21 - 1 and one second rotor core 21 - 2 are stacked in the axial direction. However, one or more first rotor cores 21 - 1 and one or more second rotor cores 21 - 2 may be alternately stacked in the axial direction.

[0196] In this modification, considering the axial structure, all first core portions 41 and all second core portions 42 are connected to the connecting portion 51, the connecting portion 58, and the annular portion 50. This allows the rotor core 21 to be integrated, thereby improving the overall strength of the rotor 20.

[0197] On the other hand, in a cross section perpendicular to the axial direction, only one of the first core portion 41 and the second core portion 42 is connected to the connecting portion 51 or the connecting portion 58. Therefore, the circumferential magnetic leakage flux Φ2 does not increase significantly. Therefore, according to this modified example, it is possible to suppress a decrease in the torque of the rotating electrical machine and improve the strength of the rotor 20.

[0198] Furthermore, the rotor 20 of this modified example may have, in addition to the first rotor core 21-1 and the second rotor core 21-2, Figure 21 The third rotor core 21-3 is shown. In this case, it is desirable to place the third rotor core 21-3 between the axially adjacent first and second rotor cores 21-1, 21-2. This allows the connection portion 51 of the first rotor core 21-1 and the connection portion 58 of the second rotor core 21-2 to be separated in the axial direction, sandwiching the third rotor core 21-3. This reduces axial magnetic flux leakage between the first and second rotor cores 21-1, 21-2.

[0199] As described above, the rotating electrical machine of this embodiment includes: a stator 10; and a rotor 20 rotatably disposed on the inner circumference of the stator 10. The rotor 20 includes: a rotor core 21; a plurality of permanent magnets 22 disposed on the rotor core 21; and a shaft 23 fixed to the center of the rotor core 21 and extending in the axial direction of the rotor 20. The rotor core 21 is formed with a plurality of holes 30 arranged circumferentially of the rotor 20. The plurality of holes 30 include a plurality of first holes 31 and a plurality of second holes 32. The plurality of permanent magnets 22 are inserted only into each of the plurality of first holes 31 of the plurality of holes 30. The plurality of first holes 31 and the plurality of second holes 32 are arranged alternately in the circumferential direction. The rotor core 21 includes a plurality of core portions 40 circumferentially arranged with each of the plurality of second holes 32 interposed therebetween. The plurality of permanent magnets 22 are magnetized so that the magnetic pole faces facing each other in the circumferential direction have different poles. The plurality of core portions 40 each include a first core portion 41 located on the magnetic pole face side of one of the plurality of permanent magnets 22 and a second core portion 42 located on the magnetic pole face side of the other of the plurality of permanent magnets 22. The rotor core 21 includes a first rotor core in at least a portion of the axial direction. The first rotor core includes an annular portion 50 and a plurality of connecting portions 51. The annular portion 50 is provided at a position closer to the inner circumference than the plurality of core portions 40 and is configured to allow the shaft 23 to be inserted. The plurality of connecting portions 51 connect the annular portion 50 to the first core portion 41 of the plurality of core portions 40, respectively. Each of the plurality of connecting portions 51 has a structure that can be separated from either the annular portion 50 or the first core portion 41. Here, the annular portion 50 is an example of a first annular portion. The plurality of connecting portions 51 is an example of a plurality of first connecting portions.

[0200] With this configuration, the plurality of first core portions 41 magnetized to the same polarity are connected to each other via the annular portion 50 and the plurality of connecting portions 51. This reduces the circumferential leakage flux Φ2 passing through the annular portion 50 and the plurality of connecting portions 51. Consequently, with this configuration, the torque output of the rotating electrical machine can be improved.

[0201] Furthermore, according to this configuration, each of the plurality of coupling portions 51 can be separated from either the annular portion 50 or the first core portion 41 , thereby improving the manufacturability of the rotor 20 .

[0202] In the rotating electrical machine of this embodiment, the plurality of coupling portions 51 are each formed of a non-magnetic material. This configuration further reduces the circumferential leakage magnetic flux Φ2 passing through the coupling portions 51, thereby further improving the torque of the rotating electrical machine.

[0203] The above-described first to third embodiments and their variations can be implemented in combination. For example, similar to the second rotor core 21 - 2 of the second or third embodiment, the rotor core 21 of the first embodiment may include a connecting portion 58 connecting the annular portion 50 and the second core portion 42 instead of the connecting portion 51 .

[0204] The rotor core 21 of the first embodiment may include a first rotor core 21-1 having a connecting portion 51 connecting the annular portion 50 and the first core portion 41, and a second rotor core 21-2 having a connecting portion 58 connecting the annular portion 50 and the second core portion 42. Furthermore, the rotor core 21 of the first embodiment may further include a third rotor core 21-3 not having the connecting portion 51 and the connecting portion 58.

[0205] Similar to the structure of the second embodiment, a non-magnetic hole may be formed in the connection portion 51 in the structure of the first embodiment or the connection portions 51 and 58 in the structure of the third embodiment.

[0206] As in the structure of Embodiment 3, the connecting portion 51 in the structure of Embodiment 1 or 2 may be configured to be detachable from either the annular portion 50 or the first core portion 41. As in the structure of Embodiment 3, the connecting portion 58 in the structure of Embodiment 2 may be configured to be detachable from either the annular portion 50 or the second core portion 42.

[0207] Description of Reference Numerals

[0208] 10 stator, 11 stator core, 12 core back, 13 teeth, 14 winding, 15 gap, 20 rotor, 21 rotor core, 21-1 first rotor core, 21-2 second rotor core, 21-3 third rotor core, 22 permanent magnet, 23 shaft, 24 protrusion, 30 hole, 31 first hole, 32 second hole, 33 outer peripheral opening, 34 inner peripheral opening, 35 outer peripheral opening, 36 inner peripheral opening, 40 core part, 41 first core part, 41a inner peripheral surface, 42 second core part, 42a inner peripheral surface, 50 annular part, 51 connecting part, 51a connecting path, 51a1 center line, 51a2, 51a3 side Surface, 51b joining boundary, 51c connecting path, 52 protrusion, 53 protrusion group, 54 non-magnetic hole, 54a, 54b edge, 54c, 54d recess, 55 fastening connection hole, 56 first auxiliary connection part, 57 second auxiliary connection part, 58 connection part, 58b joining boundary, 59 non-magnetic hole, 60 fastening connection hole, 70 end plate, 71 fastening connection hole, 80 end plate, 81 fastening connection hole, 82 fastening connection member, 91, 92 joining recess, 93, 94 joining protrusion, 100 rotating motor, 200 rotating motor, 201, 202 connecting parts, 300 rotating motor, O axis, 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 provided on the inner circumference of the stator so as to be rotatable relative to the stator, The rotor has: rotor core; a plurality of permanent magnets, wherein the plurality of permanent magnets are disposed on the rotor core; as well as a shaft fixed to the center of the rotor core and extending in the axial direction of the rotor, The rotor core is formed with a plurality of holes arranged along the circumferential direction of the rotor. The plurality of holes comprises a plurality of first holes and a plurality of second holes, The plurality of permanent magnets are respectively inserted into only each of the plurality of first holes among the plurality of holes, The plurality of first holes and the plurality of second holes are arranged alternately one by one in the circumferential direction, The rotor core includes a plurality of core parts, and the plurality of core parts are arranged in the circumferential direction with each of the plurality of second holes interposed therebetween. The plurality of permanent magnets are magnetized so that the magnetic pole faces facing each other in the circumferential direction have different poles. The plurality of core parts respectively include: a first core part located on one magnetic pole surface side of each of the plurality of permanent magnets; and a second core part located on the other magnetic pole surface side of each of the plurality of permanent magnets. The rotor core has a first rotor core in at least a portion in the axial direction. The first rotor core includes a first annular portion and a plurality of first connecting portions. The first annular portion is provided at an inner peripheral side relative to the plurality of core portions and is configured to receive the shaft. The plurality of first connecting portions respectively connect the first annular portion to the first core portion of each of the plurality of core portions. Each of the plurality of first connecting portions has at least one connecting path. The sum of the widths of the narrowest portions of each of the at least one connecting path is shorter than the length of the arc-shaped joining boundary between the first annular portion and each of the plurality of first connecting portions. The at least one connection path is a plurality of connection paths, A non-magnetic hole is formed between two adjacent connection paths among the plurality of connection paths. In a cross section perpendicular to the axial direction, the non-magnetic hole is arranged on an outer circumferential side of a circle centered on the axis of the rotor and inscribed in the plurality of permanent magnets.

2. The rotating electrical machine according to claim 1, wherein In a cross section perpendicular to the axial direction, the non-magnetic hole has a circular fastening hole through which a fastening member passes in the axial direction.

3. The rotating electrical machine according to claim 1, wherein The width of each of the at least one connecting path is constant in the radial direction of the rotor.

4. The rotating electrical machine according to claim 2, wherein: The width of each of the at least one connecting path is constant in the radial direction of the rotor.

5. The rotating electrical machine according to any one of claims 1 to 4, wherein The rotor further includes an end plate, which is arranged outside the rotor core in the axial direction. Ends of the plurality of first connection portions in the axial direction are respectively connected to the end plate.

6. The rotating electrical machine according to claim 1, wherein The rotor further includes an end plate, which is arranged outside the rotor core in the axial direction. Each of the plurality of first connection portions is fastened to the end plate by a fastening member that passes through the non-magnetic hole.

7. The rotating electrical machine according to any one of claims 1 to 4, wherein: Each of the plurality of first connection portions has a structure capable of being separated from either the first annular portion or the first core portion.

8. The rotating electrical machine according to claim 7, wherein The plurality of first connection parts are respectively formed of a non-magnetic material.

9. The rotating electrical machine according to any one of claims 1 to 4, wherein: The first annular portion includes a protrusion formed on an inner peripheral surface of the first annular portion and in contact with an outer peripheral surface of the shaft.

10. The rotating electric machine according to claim 9, wherein The protrusion is arranged at a position offset from each of the plurality of first connecting portions in the circumferential direction.

11. The rotating electrical machine according to any one of claims 1 to 4, wherein: In a cross section perpendicular to the axial direction, the first annular portion has a plurality of protrusion groups, each of the plurality of protrusion groups having at least one protrusion formed on the inner circumferential surface of the first annular portion and contacting the outer circumferential surface of the shaft. The plurality of protrusion groups are respectively provided between two adjacent first connection portions among the plurality of first connection portions in the circumferential direction.

12. The rotating electrical machine according to any one of claims 1 to 4, wherein: The shaft has a protrusion formed on an outer peripheral surface of the shaft and in contact with an inner peripheral surface of the first annular portion.

13. The rotating electrical machine according to any one of claims 1 to 4, wherein: The rotor core further includes a second rotor core, and the second rotor core is arranged to overlap with the first rotor core in the axial direction. The second rotor core includes: a second annular portion, which is arranged at a position closer to the inner circumference than the multiple core portions and for the shaft to be inserted into; and multiple second connecting portions, which respectively connect the second annular portion to the second core portions of the multiple core portions.

14. The rotating electric machine according to claim 13, wherein The rotor core further includes a third rotor core, and the third rotor core is arranged to overlap with the first rotor core and the second rotor core in the axial direction. The third rotor core includes a third annular portion, which is provided at an inner peripheral side of the plurality of core portions and into which the shaft is inserted. In a cross section perpendicular to the axial direction, the third annular portion is spaced apart from any one of the first core portion and the second core portion of the plurality of core portions.

15. The rotating electrical machine according to any one of claims 1 to 4, wherein: The circumferential width of the second hole increases from the outer peripheral side toward the inner peripheral side.

Images