Rotor core, rotor, rotating electrical machine, and method for designing rotor core

Abstract

The rotor iron core (31) is provided with a plurality of third magnetism isolating parts (37), and the third magnetism isolating parts (37) are arranged corresponding to at least one magnetic pole (33) in the plurality of magnetic poles (33). A first insertion hole (34f) is formed in the rotor core (31), and a permanent magnet (32) (front magnet (32f)) disposed closer to the front (F) in each magnetic pole (33) is inserted into the first insertion hole (34f). The third flux barrier section (37) is provided at a position facing a first side surface on the outside in the radial direction of the rotor core (31) among the side surfaces facing the short side direction in the first insertion hole (34f), and is connected to the first side surface.

Description

Technical Field

[0001] This invention relates to rotor cores, rotors, rotating electric machines, and design methods for rotor cores.

[0002] This application claims priority based on Japan Patent Application No. 2023-060098 filed on April 3, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] Rotary motors, such as those described in Patent Document 1 below, are known in the past.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5985358 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In this type of embedded permanent magnet synchronous motor (IPMSM), the goal is to realize the practical application of technology that can suppress torque pulsation (torque fluctuation).

[0009] The present invention was made in view of the foregoing circumstances, and its purpose is to reduce torque ripple.

[0010] Technical means for solving technical problems

[0011] <1> One aspect of the rotor core of the present invention is a rotor core used in a magnet-embedded motor. In the rotor core, a plurality of permanent magnets constituting magnetic poles are arranged in the circumferential direction of the rotor core. A plurality of insertion holes are formed in the rotor core, which penetrate the rotor core in the axial direction and into which the permanent magnets are inserted. In the rotor core, a magnetic shielding portion is formed corresponding to at least one of the plurality of magnetic poles. As the insertion hole, it includes a first insertion hole in which the permanent magnets arranged among the magnetic poles near the front of rotation are inserted. Relative to the first insertion hole, the magnetic shielding portion is disposed on the outer side of the rotor core in the radial direction and is disposed at a position opposite to a first side surface of the rotor core on the side surface facing the short side direction of the first insertion hole, and is connected to the first side surface.

[0012] <2> One aspect of the rotor core of the present invention is a rotor core used in a magnet-embedded motor. In the rotor core, a plurality of permanent magnets constituting magnetic poles are arranged in the circumferential direction of the rotor core. A plurality of insertion holes are formed in the rotor core, which penetrate the rotor core in the axial direction and into which the permanent magnets are inserted. In the rotor core, a magnetic shielding portion is formed corresponding to at least one of the plurality of magnetic poles. The insertion holes include a first insertion hole in which the permanent magnet of each magnetic pole is inserted near the front of rotation. At a position opposite to a first side surface of the rotor core that faces the short side surface of the first insertion hole and is located outside the radial direction of the rotor core, the magnetic shielding portion is provided close to the first insertion hole, such that the magnetic flux generated by the permanent magnet inserted in the first insertion hole is divided in the circumferential direction.

[0013] <3> Alternatively, in the rotor core of <1> or <2> above, the magnetic shielding portion has a portion that increases in the circumferential direction of the rotor core as it moves outward toward the radial direction.

[0014] <4> Alternatively, in any of the above-mentioned <1> to <3> rotor cores, the magnetic shielding part blocks the magnetic flux generated by the permanent magnet inserted into the first insertion hole, specifically the magnetic flux from the poles that moves from near the rear of rotation toward near the front of rotation.

[0015] <5> Alternatively, in any of the above-mentioned <1> to <4>, a bridge portion is provided in the rotor core in the portion located on the outer side of the radial direction relative to the magnetic shielding portion.

[0016] <6> A rotor according to one aspect of the present invention includes: a rotor core as described in any of the aspects <1> to <5>; and permanent magnets embedded in the rotor core and forming magnetic poles, wherein a plurality of sets are arranged in the rotor core in the circumferential direction.

[0017] <7> A rotary electric motor according to one aspect of the present invention includes: an annular stator; and a rotor as described in <6> disposed within the stator.

[0018] <8> Alternatively, in the rotary motor of <7> above, in the magnetic shielding part, on the outer peripheral side located on the outer side of the rotor in the radial direction, the circumferential opening angle θw of the rotor satisfies the following equations (1) and (2).

[0019] In the case that (2 / 5)θs<θm<(3 / 4)θs

[0020] 0<θw<(22 / 7)θm-(44 / 35)θs…(1)

[0021] In the case that (3 / 4)θs≦θm<(9 / 10)θs

[0022] 0<θw<-(22 / 3)θm+(33 / 5)θs…(2)

[0023] θs=2π / Nslot…(3)

[0024] Here, Nslot in equation (3) above represents the number of slots in the stator.

[0025] θm represents the center position in the circumferential direction of the outer peripheral side surface and the shielding center angle formed with the outer end in the radial direction of the magnetic shielding portion extending from the first insertion hole in the front of rotation.

[0026] <9> The rotor core design method of one aspect of the present invention is the rotor core design method described in any of the aspects <1> to <5>, which includes the process of designing the position and shape of the magnetic isolation part based on the magnetic flux near the front of rotation in the magnetic pole.

[0027] <10> In the rotor core design method of <9> above, it is also possible to design the position and shape of the magnetic isolation part in the aforementioned process so that when the torque is extremely large, the magnetic flux that generates the torque in the front of rotation in the magnetic pole is blocked, and when the torque is extremely small, the magnetic flux that generates the torque in the rear of rotation in the magnetic pole is blocked.

[0028] Invention Effects

[0029] According to the present invention, torque ripple is reduced. Attached Figure Description

[0030] Figure 1 This is a diagram illustrating a rotary electric motor according to an embodiment of the present invention, and is a top view including a portion of a cross-section.

[0031] Figure 2 yes Figure 1 An enlarged top view of the stator and rotor of the rotary electric machine shown.

[0032] Figure 3 yes Figure 1 An enlarged top view of the rotor contained in the rotary electric machine shown.

[0033] Figure 4 This is a cross-sectional view of a rotary electric machine including an embodiment of the present invention, and an enlarged top view of the rotor included in the rotary electric machine.

[0034] Figure 5 It is Figure 3 A portion of the rotor is shown in a patterned and enlarged top view.

[0035] Figure 6 This is a top view of a rotary electric motor showing a comparative example.

[0036] Figure 7 This is a graph showing the results of comparing the torque fluctuations of the rotary motor based on the embodiment and the rotary motor of the comparative example through electromagnetic field analysis.

[0037] Figure 8 This is a top view showing the rotor in the rotating electric machine of the embodiment with the most appropriate reduction of torque pulsation.

[0038] Figure 9 This is a top view showing the rotor that maximizes the average torque in the rotating electric machine of the comparative example.

[0039] Figure 10 This is a graph showing the relationship between the electrical angle and torque of the rotary motor based on the embodiment and the rotary motor of the comparative example.

[0040] Figure 11 This is a top view showing the magnetic flux density vector in the rotary electric motor of the embodiment when the rotor is at an electric angle where the torque waveform of the rotary electric motor of the comparative example is extremely small.

[0041] Figure 12 This is a top view showing the magnetic flux density vector in the rotary electric machine of the comparative example when the rotor is at an electric angle where the torque waveform is extremely small.

[0042] Figure 13 This is a top view showing the magnetic flux density vector when the rotor of the rotary electric machine in the embodiment is at an electric angle where the torque waveform of the rotary electric machine in the comparative example is at its maximum.

[0043] Figure 14 This is a top view showing the magnetic flux density vector in the rotary electric machine of the comparative example when the rotor is at an electric angle where the torque waveform is extremely large. Detailed Implementation

[0044] Below, refer to Figures 1 to 14 This invention describes a rotor core, rotor, rotary electric motor, and a design method for the rotor core according to one embodiment of the present invention. The rotary electric motor is an electric motor, specifically an AC electric motor, more specifically a synchronous electric motor, and even more specifically a permanent magnet excitation type electric motor. Such an electric motor is preferably used, for example, in electric vehicles.

[0045] like Figure 1 and Figure 2As shown, the rotary electric motor 10 includes a stator 20, a rotor 30, a housing 50, and a rotating shaft 60. The stator 20 and the rotor 30 are housed in the housing 50. The stator 20 is fixed to the housing 50. The rotary electric motor 10 is an inner rotor type, with the rotor 30 located inside the stator 20.

[0046] Furthermore, in this embodiment, the rotary motor 10 is an 8-pole, 24-slot three-phase AC motor. However, the number of poles or slots, the number of phases, etc., can be appropriately changed, for example.

[0047] Furthermore, in the rotating electric machine 10, the axes of the stator 20 and the rotor 30 lie on a common axis. This common axis will be referred to as the central axis O (the central axis of the rotor 30) in the following text. The direction of the central axis O (the axial direction of the rotor core 31, described later) is called the axial direction, the direction orthogonal to the central axis O (the radial direction of the rotor core 31, described later) is called the radial direction, and the direction around the central axis O (the circumferential direction of the rotor core 31, described later) is called the circumferential direction.

[0048] The stator 20 includes a stator core 21 and windings not shown.

[0049] The stator core 21 includes a cylindrical back 22 (yoke) and multiple teeth 23.

[0050] The back of the core 22 is formed in a ring shape when viewed from above in the axial direction of the rotary motor 10.

[0051] Multiple teeth 23 protrude from the back of the core 22 toward the radially inward side (along the radial direction toward the central axis O of the back of the core 22). The multiple teeth 23 are arranged at equal intervals in the circumferential direction. In this embodiment, 24 teeth 23 are provided at 15-degree intervals around the central axis O. The multiple teeth 23 are formed to have the same shape and size as each other. Grooves 24 are formed between adjacent teeth 23 in the circumferential direction.

[0052] The winding is wound around tooth 23. The winding can be wound in a concentrated manner or in a dispersed manner.

[0053] like Figure 3 As shown, the rotor 30 is positioned inside the stator 20 (stator core 21) in the radial direction. The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32.

[0054] The rotor core 31 is formed into a cylindrical shape coaxially arranged with the stator 20. The rotating shaft 60 is disposed within the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31 in such a way that it rotates together with the rotor core 31.

[0055] Multiple permanent magnets 32 are fixed to the rotor core 31. Multiple magnetic poles 33 are provided in the rotor core 31. In this embodiment, two permanent magnets 32 together constitute one magnetic pole 33. The multiple groups of permanent magnets 32 constituting the multiple magnetic poles 33 are arranged at equal intervals in the circumferential direction. In this embodiment, eight groups (16 in total) of permanent magnets 32 are provided at 45-degree intervals around the central axis O.

[0056] The rotary electric motor 10 is an embedded permanent magnet synchronous motor (IPMSM). Multiple insertion holes 34 are formed in the rotor core 31, extending through the rotor core 31 in the axial direction. Each insertion hole 34 corresponds to a multiple permanent magnet 32. Each permanent magnet 32 ​​is fixed to the rotor core 31 in a state where it is inserted into its corresponding insertion hole 34. That is, the insertion holes 34 form a space for mounting the permanent magnet 32. Figure 3 In the illustrated embodiment, the permanent magnet 32 ​​has a quadrilateral shape along its length, and the insertion hole 34 also has a shape that includes a quadrilateral shape with the same length direction. The permanent magnet 32 ​​can be fixed to the rotor core 31, for example, by bonding the outer surface of the permanent magnet 32 ​​to the inner surface of the insertion hole 34 with an adhesive.

[0057] Furthermore, the stator core 21 and rotor core 31 can be made of laminated cores. Laminated cores are formed by stacking multiple electromagnetic steel plates. The stacked electromagnetic steel plates are fixed to each other, for example, by riveting, bonding, or welding.

[0058] The electromagnetic steel sheets forming the stator core 21 and rotor core 31 are formed, for example, by punching or processing an electromagnetic steel sheet as a base material. Known electromagnetic steel sheets can be used as the electromagnetic steel sheets. The chemical composition of the electromagnetic steel sheets is not particularly limited. In this embodiment, a non-oriented electromagnetic steel sheet is used. For example, a non-oriented electromagnetic steel strip according to JIS C2552:2014 can be used as the non-oriented electromagnetic steel sheet. However, an oriented electromagnetic steel sheet can also be used instead of a non-oriented electromagnetic steel sheet. For example, an oriented electromagnetic steel strip according to JIS C 2553:2012 can be used as the oriented electromagnetic steel sheet.

[0059] To improve the workability of electromagnetic steel sheets and reduce iron loss in laminated cores, insulating films are applied to both sides of the electromagnetic steel sheets. Materials constituting the insulating films can include, for example, (1) inorganic compounds, (2) organic resins, and (3) mixtures of inorganic compounds and organic resins. Examples of inorganic compounds include, for example, (1) complexes of dichromate and boric acid, and (2) complexes of phosphate and silica. Examples of organic resins include epoxy resins, acrylic resins, styrene acrylic resins, polyester resins, silicone resins, and fluororesins.

[0060] The rotor 30 will now be described in detail.

[0061] like Figure 3 As shown, as previously described, permanent magnets 32 are embedded in the rotor core 31, with two magnets forming a pair to constitute a magnetic pole 33. Multiple pairs of permanent magnets 32 are arranged circumferentially in the rotor core 31 (eight pairs in the illustrated example). In the illustrated example, the permanent magnets 32 are cuboid in shape. The permanent magnets 32 appear rectangular in top view.

[0062] In the aforementioned top view, a pair of permanent magnets 32 are configured in a V-shape with inwardly protruding radial direction. In the aforementioned top view, the pair of permanent magnets 32 are arranged linearly symmetrically with respect to the d-axis Ld. In the aforementioned top view, the d-axis Ld passes through the central axis O and the center of the circumferential direction of each magnetic pole 33. Similarly, the insertion hole 34, on which the pair of permanent magnets 32 are disposed, is also arranged approximately linearly symmetrically with respect to the d-axis Ld.

[0063] In the aforementioned top view, the insertion hole 34 is larger on both the q-axis Lq side and the d-axis Ld side compared to the permanent magnet 32. In the aforementioned top view, the q-axis Lq passes between the central axis O and the two adjacent magnetic poles 33 in the circumferential direction. In the aforementioned top view, the q-axis Lq passes through the center of the circumferential direction between the two magnetic poles 33. The q-axis Lq and the d-axis Ld are magnetically and electrically orthogonal. The portions of the insertion hole 34 located on the q-axis Lq side and the d-axis Ld side relative to the permanent magnet 32, respectively, form the magnetic isolation portions 35 and 36. In other words, magnetic isolation portions 35 and 36 are provided at both ends of the permanent magnet 32 ​​on the q-axis Lq side and the d-axis Ld side. The magnetic isolation portions 35 and 36 are magnetic gaps that penetrate the rotor core 31 in the axial direction. The magnetic isolation sections 35 and 36 reduce the magnetic flux (hereinafter also referred to as circulating flux) circulating within the rotor 30 from the permanent magnet 32, or change the inflow path of the magnetic flux from the permanent magnet 32 ​​toward the stator 20. Thus, the magnetic flux (hereinafter simply referred to as magnetic flux) of the permanent magnet 32 ​​is effectively transmitted to the stator 20, resulting in high torque output. It can be considered that the magnetic isolation sections 35 and 36 guide the magnetic flux to the stator 20.

[0064] The rotor 30 includes a first magnetic shielding part 35 and a second magnetic shielding part 36 as magnetic shielding parts 35 and 36.

[0065] The first magnetic shielding part 35 and the second magnetic shielding part 36 clamp the permanent magnet 32 ​​from both ends along its length. This allows the magnetic flux to be effectively transmitted to the stator 20. The first magnetic shielding part 35 is located on the q-axis Lq side relative to each permanent magnet 32. The first magnetic shielding part 35 is located on both sides of the pair of permanent magnets 32 in the circumferential direction (rotation direction). The second magnetic shielding part 36 is located on the d-axis Ld side relative to each permanent magnet 32. The second magnetic shielding part 36 is located at the center of the pair of permanent magnets 32 in the circumferential direction (rotation direction).

[0066] Here, in the following text, the forward direction (rotational forward) of the rotary motor 10 in the circumferential direction will be simply referred to as forward F, and the backward direction in the rotational direction will be simply referred to as backward R. Furthermore, in the case of a rotary motor 10 that can rotate in two directions around its central axis O, the aforementioned rotational direction refers to the main rotational direction of the rotary motor 10. In the illustrated example, counterclockwise rotation when observing the paper is defined as forward F, and clockwise rotation as backward R.

[0067] The plurality of insertion holes 34 includes a plurality of first insertion holes 34f. In each of the plurality of first insertion holes 34f, a permanent magnet 32 ​​is inserted, positioned near the front F among the magnetic poles 33 formed by pairs of permanent magnets 32. Each pair of permanent magnets 32 includes a front magnet 32f and a rear magnet 32r. The front magnet 32f is positioned at the front F relative to the rear magnet 32r. The front magnet 32f is inserted into the first insertion hole 34f.

[0068] The rotor 30 also includes a plurality of third magnetic isolation portions (magnetic isolation sections) 37 and a plurality of bridge sections 38. The plurality of third magnetic isolation portions 37 are respectively provided corresponding to a plurality of magnetic poles 33. In this embodiment, one third magnetic isolation portion 37 is provided for each magnetic pole 33. The third magnetic isolation portion 37 is provided relative to the front magnet 32f, but not relative to the rear magnet 32r. The third magnetic isolation portion 37 is provided only for the front magnet 32f. The plurality of third magnetic isolation portions 37 are magnetic gaps that penetrate the rotor core 31 in the axial direction. The third magnetic isolation portion 37 is provided in the first insertion hole 34f at a position opposite to the radially outer side (hereinafter also referred to as the first side 34f1) among the side surfaces facing the width direction. The third magnetic isolation portion 37 is formed to divide (cut off) the magnetic flux generated by the front magnet 32f in the circumferential direction. The third magnetic isolation portion 37 is connected to the radially outer side of the first insertion hole 34f. In other words, the third magnetic isolation portion 37 is connected to the radially outer side of the first insertion hole 34f. That is, the third magnetic shielding part 37 is connected to the first side surface 34f1. In the illustrated example, the third magnetic shielding part 37 is connected to a portion of the first side surface 34f1 in top view. On the other hand, the third magnetic shielding part 37 is connected along the entire length of the first side surface 34f1 in the axial direction. However, as... Figure 4As shown, the third magnetic shielding portion 37 can also be slightly separated from the first insertion hole 34f in the radial direction. That is, the third magnetic shielding portion 37 can also be close to the radial direction outside the first insertion hole 34f. In other words, the third magnetic shielding portion 37 can also approach the first insertion hole 34f from the radial direction outside. The distance d (mm) between the third magnetic shielding portion 37 and the first insertion hole 34f is, for example, 0.03mm or less. The distance d is the shortest distance between the third magnetic shielding portion 37 and the first insertion hole 34f. At this time, there is a portion between the third magnetic shielding portion 37 and the first insertion hole 34f that can become a path for magnetic flux. However, if the radial length (area) of this portion is sufficiently small, magnetic saturation occurs. Therefore, in essence, the magnetic flux generated by the front magnet 32f is divided in the circumferential direction by the third magnetic shielding portion 37. For example, the third magnetic shielding portion 37 can be a distance less than the radial length (width of the bridge portion 38) of the bridge portion 38 from the radial direction outside the first insertion hole 34f.

[0069] In this embodiment, an example in which the third magnetic isolation portion 37 is provided corresponding to all magnetic poles 33 is described, but the third magnetic isolation portion 37 may also be provided corresponding to at least one of the multiple magnetic poles 33. For example, there may be only one third magnetic isolation portion 37.

[0070] like Figure 5 As shown, in a top view taken from the axial direction, the radially inner portion of the third magnetic shielding part 37 is tapered towards the radially inner side (i.e., the first insertion hole 34f). The radially inner end portion 37a of the third magnetic shielding part 37 is connected to the first insertion hole 34f from the radially outer side. The radially outer side of the third magnetic shielding part 37 is connected to the front magnet 32f inserted into the first insertion hole 34f. The third magnetic shielding part 37 is formed to increase in size in the circumferential direction of the rotor core 31 as it moves towards the radially outer side. The third magnetic shielding part 37 blocks the magnetic flux (magnetic flux) generated when the rotor 30 rotates, specifically the magnetic flux near the front F of the magnetic pole 33.

[0071] The third magnetic shielding section 37 has an outer peripheral side surface 37b located on the outer side in the radial direction. The outer peripheral side surface 37b is located on the inner side in the radial direction relative to the outer peripheral surface 31a of the rotor core 31. The outer peripheral side surface 37b is formed along the outer peripheral surface 31a. The term "outer peripheral side surface 37b along the outer peripheral surface 31a" includes not only the case where the outer peripheral side surface 37b is completely parallel to the outer peripheral surface 31a, but also the case where the outer peripheral side surface 37b is substantially parallel to the outer peripheral surface 31a. "Substantially parallel" means that the radial length of the bridge portion 38 (described later) is substantially equal in the circumferential length of the bridge portion 38. The rotor core 31 has a bridge portion 38 between the outer peripheral surface 31a and the outer peripheral side surface 37b. That is, in the rotor core 31, the bridge portions 38 are respectively provided on the outer side in the radial direction relative to the plurality of third magnetic shielding sections 37.

[0072] Multiple bridge sections 38 can utilize magnetic saturation to prevent magnetic flux from passing through them. Furthermore, while magnetic saturation can prevent magnetic flux from passing through the bridge sections 38 when the rotor 30 operates at a torque above a specified value, magnetic flux can still pass through them when operating at a torque below the specified value. The circumferential length or radial width (radial length) of the bridge sections 38 is appropriately designed based on the rotational speed or shape of the rotary electric machine 10. The radial width of the bridge sections 38 will be described in detail later.

[0073] In this embodiment, the third magnetic shielding part 37 has: an inner end portion 37a that is connected to the first insertion hole 34f (the closest part); a widening portion 37g that widens in the circumferential direction from the inner end portion 37a toward the outer side in the radial direction; and a connecting portion 37h that is connected to the bridge portion 38 formed along the outer peripheral side surface 37b.

[0074] Furthermore, the inner end portion 37a is either dot-shaped or line-shaped. Here, when the inner end portion 37a is large in the circumferential direction, the portion of the third magnetically shielding portion 37 that faces the front magnet 32f from the outer radial direction becomes larger, hindering the magnetic flux generated by the front magnet 32f, and reducing the amount of magnetic flux generated. Therefore, it is preferable for the circumferential length of the inner end portion 37a to be shorter (e.g., less than 5% of the long side of the front magnet 32f).

[0075] Furthermore, the widened portion 37g is a triangular shape that protrudes inward in the radial direction. Here, the widened portion 37g can be widened in a straight line or in a curved line.

[0076] Furthermore, the connecting portion 37h is rectangular in shape and extends radially. The shape of the connecting portion 37h is not particularly limited, and it can be modified to form other configurations where a bridge portion 38 is formed between the outer peripheral side surface 37b and the outer peripheral surface 31a. For example, if the circumferential length of the outer radial side of the widened portion 37g is the same as the circumferential length of the outer peripheral side surface 37b, the circumferential size of the connecting portion 37h can also be equal in length along the radial direction. Furthermore, if, for example, the circumferential length of the outer radial side of the widened portion 37g is greater than the circumferential length of the outer peripheral side surface 37b, part or all of the circumferential size of the connecting portion 37h can narrow in the circumferential direction as it moves outwards along the radial direction.

[0077] The following is a detailed explanation of the third magnetic shielding section 37.

[0078] The third magnetic shielding part 37 determines its position and shape based on the shielding center angle θm (radians), the shielding opening angle θw (radians), and the shielding connection position Xm.

[0079] The shielding center angle θm represents the angle formed in the circumferential direction between the shielding center position 37c and the outer end 35a with the central axis O as the center. The shielding center position 37c represents the center position in the circumferential direction of the outer peripheral side surface 37b of the third magnetic shielding part 37. The outer end 35a represents the outer end in the radial direction of the front F of the first magnetic shielding part 35.

[0080] The shielding opening angle θw represents the angle formed in the circumferential direction by the front end portion 37d and the rear end portion 37e of the shielding with the central axis O as the center. The front end portion 37d represents the end on the front F side of the outer peripheral side surface 37b of the third magnetic shielding part 37. The rear end portion 37e represents the end on the rear R side of the outer peripheral side surface 37b of the third magnetic shielding part 37.

[0081] The center angle θs of the slot represents slot 24 of stator 20 (refer to...). Figure 1 The central angle of each.

[0082] The blocking connection position Xm represents the position of the outer surface of the front magnet 32f in the circumferential direction (length direction) relative to the magnet length Mw.

[0083] In addition, such as Figure 4 As shown, when the third magnetic shielding part 37 is slightly separated from the first insertion hole 34f, the blocking connection position Xm represents the position on the outer surface of the front magnet 32f where the third magnetic shielding part 37 is closest to the first insertion hole 34f, relative to the circumferential direction (length direction) of the magnet length Mw. Furthermore, the blocking connection position Xm is defined as the distance d between the third magnetic shielding part 37 and the first insertion hole 34f.

[0084] Furthermore, these positions, lengths, or angles can be determined, for example, by photographing the rotor 30 as the object from above, based on the photographed image.

[0085] The third magnetic shielding part 37 is positioned and shaped in accordance with equations (1) to (4). That is,

[0086] In the case that (2 / 5)θs<θm<(3 / 4)θs

[0087] 0<θw<(22 / 7)θm-(44 / 35)θs…(1)

[0088] In the case that (3 / 4)θs≦θm<(9 / 10)θs

[0089] 0<θw<-(22 / 3)θm+(33 / 5)θs…(2)

[0090] θs=2π / Nslot…(3)

[0091] Where Nslot represents the number of slots in stator 20.

[0092] 0≦Xm≦Mw…(4)

[0093] Furthermore, the radial length of the third magnetic isolation section 37 is determined such that the magnetic flux density in the bridge section 38 is greater than the saturation magnetic flux density of the soft magnetic material. For example, the radial width of the bridge section 38 is 0.15 mm, and the magnetic flux density at the center of the bridge is 2.45 T. For example, when the saturation magnetic flux density of the rotor core 31 is set to 1.95 T, the magnetic flux density of 2.45 T at the center of the bridge exceeds the saturation magnetic flux density of the rotor core 31.

[0094] Here, the third magnetic isolation section 37 is provided for the purpose of blocking the magnetic flux of the magnet. Therefore, the bridge section 38, which is located on the outer side of the third magnetic isolation section 37 in the radial direction, also needs to be sufficiently narrowed so that the magnetic flux of the magnet cannot pass through.

[0095] On the other hand, from the perspective of the mechanical strength of the rotor core 31, in order to ensure the strength of the bridge portion 38, the radial width of the bridge portion 38 needs to be maintained above a certain level. Therefore, it is considered sufficient to set the width of the bridge portion 38 such that the magnetic flux density exceeds the saturation magnetic flux density. The magnetic flux density of the bridge portion 38 can be obtained, for example, by analyzing the electromagnetic field of the rotating electric machine 10 model.

[0096] Next, according to Figures 5 to 7 Explain the reasons for setting the shielding center angle θm, shielding opening angle θw, and shielding connection position Xm according to equations (1) to (4).

[0097] Figure 5The rotary motor 10 of the embodiment shown has a third magnetic shielding part 37 in the rotor core 31. Figure 6 The rotary motor 100 shown in the comparative example differs from the rotary motor 10 of the embodiment only in that the rotor core 101 does not have a third magnetic shielding part 37; the other configurations are the same as those of the rotary motor 10 of the embodiment. Figure 7 This is a graph showing the results of comparing the torque fluctuations of the rotary motor 10 based on the embodiment and the rotary motor 100 of the comparative example through electromagnetic field analysis.

[0098] Figure 7 The vertical axis shows (obstruction opening angle θw) / (slot center angle θs) (%), and the horizontal axis shows (obstruction center angle θm) / (slot center angle θs) (%). Here, considering that even with small torque fluctuations, a small average torque can limit applications, the rotary motor 10 of the embodiment and the rotary motor 100 of the comparative example are compared using (torque fluctuation) / (average torque) as an evaluation value. The smaller this evaluation value, the better the performance of the rotary motors 10 and 100.

[0099] Curve G1 is a line (contour line) representing the condition that the evaluation value of the rotary motor 10 of the embodiment becomes equal to the evaluation value of the rotary motor 100 of the comparative example. In the inner region E1, which is located further inside than curve G1, the evaluation value of the rotary motor 10 of the embodiment is less than the evaluation value of the rotary motor 100 of the comparative example (excellent).

[0100] Curve G2 is the line defined by equations (1) and (2) described later.

[0101] Furthermore, curve G1 is the result of electromagnetic field analysis when the shielding connection position Xm of the inner end 37a in the third magnetic shielding part 37 is positioned at the center of the magnet length Mw in the front magnet 32f (i.e., Xm = (1 / 2)Mw). The reason for performing electromagnetic field analysis when curve G1 is set to Xm = (1 / 2)Mw is as follows.

[0102] That is, the effect of moving the blocking connection position Xm of the inner end portion 37a of the third magnetic shielding part 37 is limited. Even if the blocking connection position Xm is moved within the range of 0 to (maximum magnet length) of the magnet length Mw, it has no effect on the range of torque ripple reduction. For example, when the blocking connection position Xm is moved within the range of 0 ≤ Mw ≤ (maximum magnet length), the magnetic flux that contributes to torque will change. Corresponding to the change in magnetic flux, the average torque will increase or decrease, but along with the increase or decrease in average torque, torque ripple will also increase or decrease. Therefore, the effect on the evaluation value is offset, and the evaluation value for the reduction of torque ripple will not change significantly.

[0103] The results of electromagnetic field analysis show that in the inner region E1 of curve G1, the torque fluctuation of the rotating motor 10 is smaller than that of the rotating motor 100, and the torque pulsation is reduced. Here, in the region E2 outside curve G2, within curve G1, the reduction in torque fluctuation of the rotating motor 10 is relatively small. That is, the torque fluctuation of the rotating motor 10 in the inner region E3 of curve G2 is appropriately smaller than that of the rotating motor 100. Therefore, in the inner region E3 of curve G2, the torque pulsation of the rotating motor 10 is appropriately reduced compared to the rotating motor 100. The inner region E3 of curve G2 corresponds to the range of the shielding center angle θm and the shielding opening angle θw expressed by equation (1) and equation (2), respectively.

[0104] exist Figure 7 In the graph, 40% of the horizontal axis (shading center angle θm) / (groove center angle θs) corresponds to the position of (2 / 5)θs in equation (1). 75% of the horizontal axis (shading center angle θm) / (groove center angle θs) corresponds to the position of (3 / 4)θs in equations (1) and (2). 90% of the horizontal axis (shading center angle θm) / (groove center angle θs) corresponds to the position of (9 / 10)θs in equation (2).

[0105] In addition, Figure 7 In the chart, when the vertical axis (blocking opening angle θw) / (slot center angle θs) is 45.8% and the horizontal axis (blocking center angle θm) / (slot center angle θs) is 75%, the evaluation value is the smallest, and the torque ripple is reduced optimally.

[0106] Based on the results of the electromagnetic field analysis, the position and properties of the third magnetic isolation part 37 are determined so that equations (1) to (4) are satisfied.

[0107] Next, according to Figures 8 to 10 This section describes an example of comparing the torque pulsation of the rotary motor 10 of the embodiment with that of the rotary motor 110 of the comparative example.

[0108] Figure 8 The rotor 30 shown in the embodiment of the rotary electric motor 10 is the one in which torque pulsation is most appropriately reduced. Figure 9 The rotor 112 shown in the rotary motor 110 of the comparative example maximizes the average torque. Figure 10 This is a graph showing the relationship (torque waveform) between the electrical angle and torque of the rotary motor 10 of the embodiment and the rotary motor 110 of the comparative example. Figure 10 The torque (Nm) is shown on the vertical axis, and the electrical angle (°) is shown on the horizontal axis. Furthermore, the shapes of these rotors 30 and 112 were obtained according to the analytical method described in Japanese Patent Application Publication No. 2021-114099.

[0109] exist Figure 10 In the diagram, curve G3 represents the torque waveform of the rotary motor 10 of the embodiment. Curve G4 represents the torque waveform of the rotary motor 110 of the comparative example. By comparing the torque waveforms of curve G3 and curve G4, it can be confirmed that the torque ripple of curve G3 is much smaller than that of curve G4. Therefore, it can be confirmed that the torque ripple of the rotary motor 10 of the embodiment is much smaller than that of the rotary motor 110 of the comparative example.

[0110] Next, according to Figures 11 to 14 ,illustrate Figure 8 The rotary motor 10 of the illustrated embodiment and Figure 9 The magnetic flux density vector in the rotary electric motor 110 of the comparative example shown.

[0111] First of all, Figure 11 , Figure 12 In the embodiment, the rotor 30 and the rotor 112 of the comparative example are located in... Figure 10 The curve G4 shows the torque waveform of the comparative example rotary motor 110, which generates a magnetic flux density vector when the electrical angle θ1 is extremely small.

[0112] Figure 11 The magnetic flux density vector is shown when the rotor 30 is at an electrical angle θ1 in the rotary motor 10 of the embodiment.

[0113] like Figure 11 As shown, in the rotary motor 10 of this embodiment, the magnetic flux from the rear R-side portion 32fr to the front F-side of the front magnet 32f is blocked by the third magnetic shielding portion 37. The main paths of the magnetic flux, which are divided in the circumferential direction, are directed toward different teeth 23. Therefore, it is possible to prevent the magnetic flux from being directed toward the teeth 23 located on the rear R-side relative to the front magnet 32f. Therefore, it is possible to reduce the negative torque generated by the magnetic flux. Thus, the rotary motor 10 of this embodiment can suppress the torque reduction in electrical angle θ1.

[0114] Figure 12 The magnetic flux density vector is shown in the rotary electric motor 110 of the comparative example when the rotor 112 is at an electrical angle θ1.

[0115] like Figure 12 As shown, in the comparative example rotary motor 110, the magnetic flux from the rear R-side portion 32fr of the front magnet 32f to the front F-side is directed, as indicated by arrow A, to the tooth 23 located rear R-side relative to the front magnet 32f. The magnetic flux directed to the tooth 23 generates a negative torque. Therefore, the torque in the electrical angle θ1 of the comparative example rotary motor 110 becomes a minimum.

[0116] Next, in Figure 13 , Figure 14In the embodiment, the rotor 30 and the rotor 112 of the comparative example are located at... Figure 10 The torque waveform of the comparative example rotary motor 110, shown by curve G4, is used to illustrate the magnetic flux density vector generated when the electric angle θ2 becomes extremely large.

[0117] Figure 13 The magnetic flux density vector is shown when the rotor 30 is at an electrical angle θ2 in the rotary motor 10 of the embodiment.

[0118] like Figure 13 As shown, in the rotary motor 10 of this embodiment, the magnetic flux coming from the rear R-side portion 32fr of the front magnet 32f to the front F-side is blocked by the third magnetic shielding portion 37. Therefore, it is possible to prevent this magnetic flux from heading towards the tooth 23 located on the front F-side relative to the front magnet 32f, as indicated by arrow B. That is, the third magnetic shielding portion 37 functions so that only the magnetic flux coming from the front F-side portion 32ff of the front magnet 32f to the front F-side goes towards the tooth 23 located on the front F-side relative to the front magnet 32f. Therefore, the positive torque generated by the magnetic flux can be reduced. Thus, the rotary motor 10 of this embodiment can suppress the torque in the electrical angle θ2 more effectively.

[0119] Thus, as Figure 10 As shown in curve G3, the rotary motor 10 of the embodiment suppresses the torque reduction at electrical angle θ1 and can suppress the torque at electrical angle θ2 to a lesser extent. As a result, the rotary motor 10 of the embodiment suppresses the difference between the maximum torque and the minimum torque to almost non-existent, and as an IPMSM, the torque ripple of the rotary motor 10 can be reduced.

[0120] Figure 14 The magnetic flux density vector of the rotor 112 in the rotary electric machine 110 of the comparative example is shown when the rotor 112 is at an electric angle θ2.

[0121] like Figure 14 As shown, in the rotor core 31 of the comparative example rotary motor 110, there is no third magnetic isolation section for dividing the magnetic flux from the front magnet 32f as described above. Therefore, in the comparative example rotary motor 110, most of the magnetic flux from the front magnet 32f flows from both the front F-side portion 32ff and the rear R-side portion 32fr of the front magnet 32f to the tooth 23 located on the front F-side relative to the front magnet 32f, as indicated by arrow C. Therefore, the magnetic flux coming from the entire surface of the front magnet 32f to the front F-side contributes to a positive torque. Consequently, the torque at electrical angle θ2 of the comparative example rotary motor 110 reaches a maximum value.

[0122] Thus, the comparative example rotary motor 110, as Figure 10As shown in curve G4, the torque at electrical angle θ1 becomes a minimum, and the torque at electrical angle θ2 becomes a maximum. As a result, according to the rotary motor 110 of the comparative example, the difference between the maximum torque and the minimum torque becomes larger, and the torque pulsation becomes larger.

[0123] The following effects are obtained by designing the rotor core 31, rotor 30, rotary motor 10 and rotor core 31 according to the above-described embodiments.

[0124] Here, the inventors of this application have discovered that by designing the position and shape of the third magnetic isolation part 37 based on the magnetic flux near the front F in the magnetic pole 33, the torque pulsation of the IPMSM can be reduced.

[0125] Therefore, the design method of the rotor core 31 includes a step of designing the position and shape of the third magnetic isolation part 37. Specifically, in the design method of the rotor core 31, when the torque is extremely large, the third magnetic isolation part 37 blocks the magnetic flux in the magnetic pole 33 near the front F that generates the torque at the front F. Furthermore, when the torque is extremely small, the third magnetic isolation part 37 blocks the magnetic flux in the magnetic pole 33 near the front F that generates the torque at the rear R. Thus, in this design method, the position and shape of the third magnetic isolation part 37 are designed based on the magnetic flux in the magnetic pole 33 near the front F.

[0126] In the design process of the rotor core 31, the front magnet 32f of the magnetic poles 33 is inserted into the first insertion hole 34f, and a third magnetic isolation part 37 is provided on the outer side of the rotor core 31 in the radial direction relative to the first insertion hole 34f. Furthermore, the third magnetic isolation part 37 is connected to the first insertion hole 34f from the outer side in the radial direction. Therefore, the magnetic flux emitted from the front magnet 32f and destined for the forward F can be divided into a front F side and a rear R side by the third magnetic isolation part 37. Thus, when the torque is extremely large, by blocking the portion of the magnetic flux on the rear R side (the magnetic flux at part 32fr) destined for the forward F by the third magnetic isolation part 37, a portion of the magnetic flux generating the torque at the front F is blocked. When the torque is extremely small, by blocking the portion of the magnetic flux on the front F side (the magnetic flux at part 32ff) destined for the rear R by the third magnetic isolation part 37, a portion of the magnetic flux generating the torque toward the rear R can be blocked. In this way, by suppressing the torque of the front F when the torque is at its maximum and suppressing the torque of the rear R when the torque is at its minimum, the torque pulsation of the rotary motor 10 can be reduced as an IPMSM.

[0127] Furthermore, the third magnetic shielding portion 37 has a portion that increases in the circumferential direction of the rotor core 31 as it moves outward in the radial direction. Specifically, the portion of the third magnetic shielding portion 37 near the first insertion hole 34f is tapered towards the front end of the first insertion hole 34f, and its inner end portion 37a connects to the first insertion hole 34f from the outer side in the radial direction. Therefore, the area of ​​the inner end portion 37a of the third magnetic shielding portion 37 connected to the first insertion hole 34f can be reduced to a smaller extent. Consequently, magnetic flux can be appropriately generated from the front magnet 32f without being excessively blocked by the third magnetic shielding portion 37.

[0128] Furthermore, by making the third magnetic isolation section 37 larger in the circumferential direction of the rotor core 31 as it moves outward in the radial direction, it is possible to prevent magnetic flux emitted from the front magnet 32f from passing through the third magnetic isolation section 37.

[0129] In this way, magnetic flux can be appropriately generated from the front magnet 32f, and the magnetic flux emitted from the front magnet 32f can be prevented from passing through the front magnet 32f, thereby further reducing torque pulsation appropriately.

[0130] Furthermore, by connecting the front magnet 32f, which is inserted into the first insertion hole 34f, to the third magnetic shielding part 37, magnetic flux emitted from the front magnet 32f can be prevented from passing between the front magnet 32f and the third magnetic shielding part 37. As a result, torque pulsation can be further reduced appropriately.

[0131] Furthermore, the third magnetic shielding part 37 blocks the magnetic flux generated from the front magnet 32f that flows from near the rear R to near the front F. Therefore, when the torque is extremely large, blocking the magnetic flux that generates the torque at the front F can suppress the torque at the front F. Furthermore, when the torque is extremely small, blocking the magnetic flux that generates the torque at the rear R can suppress the torque at the rear R. As a result, torque pulsation can be reduced.

[0132] Furthermore, by setting the magnetic flux density through the bridge section 38 to exceed the saturation flux, it is possible to prevent magnetic flux from passing through the bridge section 38. As a result, torque ripple can be further reduced appropriately.

[0133] Furthermore, when the blocking center angle θm is in the range of (2 / 5)θs < θm < (3 / 4)θs, the third magnetic shielding part 37 is located on the front F side of the front magnet 32f. In this case, the blocking opening angle θw of the third magnetic shielding part 37 is set to 0 < θw < (22 / 7)θm - (44 / 35)θs. Thus, the magnetic flux that generates the torque F in front can be blocked when the torque is extremely large, and the magnetic flux that generates the torque R in rear can be blocked when the torque is extremely small. Therefore, by suppressing the torque F in front when the torque is extremely large and suppressing the torque R in rear when the torque is extremely small, the torque pulsation of the rotary motor 10 can be reduced as an IPMSM.

[0134] Furthermore, when the blocking center angle θm is in the range of (3 / 4)θs≦θm<(9 / 10)θs, the third magnetic shielding part 37 is located on the rear R side of the front magnet 32f. In this case, the blocking opening angle θw of the third magnetic shielding part 37 is set to 0<θw<-(22 / 3)θm+(33 / 5)θs. Thus, it is possible to block the magnetic flux that generates the torque of the front F when the torque is extremely large, and to block the magnetic flux that generates the torque of the rear R when the torque is extremely small. Therefore, by suppressing the torque of the front F when the torque is extremely large and suppressing the torque of the rear R when the torque is extremely small, the torque pulsation of the rotary motor 10 can be reduced as an IPMSM.

[0135] Furthermore, the scope of the present invention is not limited to the foregoing embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0136] The shape of the stator 20 is not limited to the scheme shown in the described embodiment. Specifically, the outer and inner diameters of the stator core 21, the stack thickness, the number of slots, the ratio of the circumferential to radial dimensions of the teeth 23, and the ratio of the radial dimensions of the teeth 23 to the back of the core 22 can be arbitrarily designed according to the desired characteristics of the rotary motor 10.

[0137] The shape of the rotor 30 is not limited to the scheme shown in the embodiment. Specifically, the outer and inner diameters, stack thickness, number of poles, etc. of the rotor core 31 can be arbitrarily designed according to the desired characteristics of the rotary motor 10.

[0138] In the aforementioned embodiments, both the stator core 21 and the rotor core 31 are laminated cores, but they may not be laminated cores.

[0139] The second magnetic shielding part 36 may also be omitted.

[0140] The third magnetic shielding part 37 may not penetrate the rotor core 31 in the axial direction. In this case, the third magnetic shielding part 37 may only be connected to a portion of the first side surface 34f1 in the axial direction.

[0141] In the foregoing embodiments, a magnetic pole 33 is composed of two permanent magnets 32. However, the present invention is not limited thereto. For example, a magnetic pole 33 may be composed of one permanent magnet 32, three permanent magnets 32, or four or more permanent magnets 32. Other schemes comprising one or more permanent magnets 32 may be appropriately adopted as a group of permanent magnets 32.

[0142] For example, in the case where a set of permanent magnets 32 consists of a single permanent magnet 32, this single permanent magnet 32 ​​can be a rectangular shape that is elongated in a direction orthogonal to the d-axis Ld in the aforementioned top view. In this case, the insertion hole 34 into which a single permanent magnet 32 ​​is inserted becomes the first insertion hole 34f.

[0143] For example, when there are three permanent magnets 32 in a set, and these three permanent magnets 32 are arranged in the circumferential direction, the following configuration is possible. In this case, in the aforementioned top view, the permanent magnet 32 ​​located at the center in the circumferential direction can be rectangular in length in a direction orthogonal to the d-axis Ld. Furthermore, in this case, in the aforementioned top view, the two permanent magnets 32 located on either side in the circumferential direction can extend outward in the radial direction from the d-axis Ld side towards the q-axis Lq side. In this case, among the three or more permanent magnets 32, the insertion hole 34 into which the foremost permanent magnet 32 ​​is inserted becomes the first insertion hole 34f.

[0144] Furthermore, without departing from the spirit of the invention, the constituent elements in the embodiments may be appropriately replaced with known constituent elements, and the aforementioned variations may be appropriately combined.

[0145] Industrial availability

[0146] According to the present invention, torque ripple is reduced. Therefore, it has high industrial applicability.

[0147] Explanation of reference numerals in the attached figures

[0148] 10, 100 Rotary Motors

[0149] 20 stators

[0150] 21 Stator Core

[0151] 22-core back

[0152] 23 teeth

[0153] 24 slots

[0154] 30, 112 rotors

[0155] 31 Rotor core

[0156] 31a Outer peripheral surface

[0157] 32 permanent magnets

[0158] 32f Front magnet

[0159] 32ff area

[0160] 32fr location

[0161] 32r rear magnet

[0162] 33 magnetic poles

[0163] 34 Insertion Holes

[0164] 34f First insertion hole

[0165] 34f1 First Side

[0166] 35 First magnetic shielding part (magnetic shielding part extending from the first insertion hole towards the front of rotation)

[0167] 35a Outer end

[0168] 36 Second Magnetic Insulation Section

[0169] 37 Third Magnetic Insulation Section (Magnetic Insulation Part)

[0170] 37a Inner end

[0171] 37b Outer peripheral side

[0172] 37c Center position of the obstruction

[0173] 37d occlusion of the front end

[0174] 37e Rear end shielding

[0175] 37g widened section

[0176] 37h Connection part

[0177] 38. Bridge section

[0178] 50 Housing

[0179] 60 Rotation axis

[0180] Arrow A

[0181] Arrow B

[0182] C arrow

[0183] E1 inner region

[0184] E2 area

[0185] E3 inner area

[0186] F (Front)

[0187] G1 curve

[0188] G2 curve

[0189] G3 curve

[0190] G4 curve

[0191] Ld d-axis

[0192] Lq q-axis

[0193] O Central axis

[0194] R behind

[0195] Xm obstructs connection position

[0196] θm occlusion center angle

[0197] θs center angle of the groove

[0198] θw occlusion angle

Claims

1. A rotor core, used in a magnet-embedded motor, In the rotor core, multiple sets of permanent magnets constituting magnetic poles are arranged in the circumferential direction. Multiple insertion holes are formed in the rotor core, each hole penetrating the rotor core in the axial direction, and into which the permanent magnet is inserted. In the rotor core, a magnetic isolation portion is formed, corresponding to at least one of the plurality of magnetic poles. The insertion hole includes a first insertion hole in which a permanent magnet, one of the respective magnetic poles, positioned near the front of rotation, is inserted. The magnetic shielding part is disposed at a position opposite to the first side surface of the rotor core in the radial direction, which is one of the sides facing the short side in the first insertion hole, and is connected to the first side surface.

2. A rotor core, used in a magnet-embedded motor. In the rotor core, multiple sets of permanent magnets constituting magnetic poles are arranged in the circumferential direction. A plurality of insertion holes are formed in the rotor core, the insertion holes extending through the rotor core in the axial direction, and the permanent magnets are inserted therein. In the rotor core, a magnetic isolation portion is formed, corresponding to at least one of the plurality of magnetic poles. The insertion hole includes a first insertion hole in which a permanent magnet, one of the respective magnetic poles, positioned near the front of rotation, is inserted. The magnetic shielding portion is positioned near the first insertion hole at a location opposite to the first side of the rotor core in the radial direction, which is one of the sides facing the short side of the first insertion hole, so as to divide the magnetic flux generated by the permanent magnet inserted into the first insertion hole in the circumferential direction.

3. The rotor core according to claim 1 or 2, The magnetic shielding portion has a portion that increases in the circumferential direction of the rotor core as it moves outward toward the radial direction.

4. The rotor core according to claim 1 or 2, The magnetic shielding part blocks the magnetic flux generated by the permanent magnet inserted into the first insertion hole, specifically the magnetic flux from the magnetic poles that moves from the rear of the rotation towards the front of the rotation.

5. The rotor core according to claim 1 or 2, In the rotor core, a bridge portion is provided on the portion located on the outer side of the radial direction relative to the magnetic shielding portion.

6. A rotor, comprising: The rotor core as described in claim 1 or 2; as well as Permanent magnets are embedded in the rotor core and form magnetic poles, and multiple sets are arranged in the rotor core in the circumferential direction.

7. A rotary electric motor, comprising: Ring-shaped stator; as well as The rotor of claim 6 is configured within the stator.

8. The rotary motor according to claim 7, In the magnetic shielding part, on the outer peripheral side located on the outer side of the rotor in the radial direction, the circumferential blocking opening angle θw of the rotor satisfies the following equations (1) and (2). In the case that (2 / 5)θs<θm<(3 / 4)θs 0<θw<(22 / 7)θm-(44 / 35)θs…(1) In the case that (3 / 4)θs≦θm<(9 / 10)θs 0<θw<-(22 / 3)θm+(33 / 5)θs…(2) θs=2π / Nslot…(3) Here, Nslot in equation (3) above represents the number of slots in the stator. θm represents the center position in the circumferential direction of the outer peripheral side surface and the shielding center angle formed with the outer end in the radial direction of the magnetic shielding portion extending from the first insertion hole toward the front of rotation.

9. A method for designing a rotor core, which is the method for designing a rotor core as described in claim 1 or 2. The process includes designing the position and shape of the magnetic isolation part based on the magnetic flux near the front of rotation in the magnetic pole.

10. The rotor core design method according to claim 9, In the process described above, the position and shape of the magnetic shielding part are designed such that when the torque is extremely large, the magnetic flux in the magnetic pole near the front of rotation that generates the torque in front of rotation is blocked, and when the torque is extremely small, the magnetic flux in the magnetic pole near the front of rotation that generates the torque in rearward rotation is blocked.

Images