JP2020182358A - Rotor of rotating electric machine - Google Patents

Abstract

To provide a rotor of a rotating electric machine that can reduce torque ripple.SOLUTION: A rotor of a rotating electric machine includes a pair of first magnet embedding holes 34A and a pair of second magnet embedding holes 34B formed for each magnetic pole of a rotor core 24, a pair of first permanent magnets M1, a pair of second permanent magnets M2, and a pair of first groove G1, a pair of second groove G2, and a pair of third groove G3 formed on the outer peripheral surface of the rotor core and extending parallel to the central axis. The first groove, the second groove, and the third groove are provided line-symmetrically with respect to a d-axis, the first groove is located adjacent to the d-axis, and the second groove is provided between the first groove and a second bridge portion B2, and the third groove is provided between the second bridge portion B2 and a third bridge portion B3. An electrical angle between the center in the width direction of the first groove and the d-axis is 3 to 6 degrees, an electrical angle between the center in the width direction of the second groove and the d-axis side end of the second bridge portion is 6 to 11, and an electrical angle θ3 between the center of the third groove in the width direction and the end on the d-axis side of a fourth bridge portion is 9.5 to 12.5.SELECTED DRAWING: Figure 2

Description

An embodiment of the present invention relates to a rotor of a rotating electric machine in which a permanent magnet is provided in the rotor.

In recent years, permanent magnet type rotary electric machines using permanent magnets are being applied as electric motors or generators for trains and automobiles. The permanent magnet type rotary electric machine has a stator wound with armature windings, a rotor core, and a plurality of permanent magnets embedded in the rotor core, and is rotatably provided with respect to the stator. It is equipped with a rotor.
In this type of rotary electric machine, in order to reduce the counter electromotive force and loss, two layers of permanent magnets, that is, a pair of permanent magnets on the outer peripheral side and a pair of permanent magnets on the inner peripheral side, are attached to one magnetic pole of the rotor core. A configuration provided with a magnet has been proposed.
However, when two layers of permanent magnets are provided on one magnetic pole, the surface magnetic flux density of the rotor core can be increased, but the torque ripple on the outer peripheral surface of the rotor core may increase.

JP-A-2007-274798 Japanese Unexamined Patent Publication No. 2014-11303

An object of the embodiment of the present invention is to provide a rotor of a permanent magnet type rotary electric machine capable of reducing torque ripple.

According to the embodiment, the rotary electric machine is formed for each of a shaft that rotates around the central axis, a rotor core that is fixed to the shaft and has a plurality of magnetic poles arranged in the circumferential direction, and a magnetic pole of the rotor core. In the pair of first magnet embedding holes and the pair of second magnet embedding holes, the pair of first permanent magnets loaded and arranged in the pair of first magnet embedding holes, and the pair of second magnet embedding holes. A pair of second permanent magnets loaded and arranged, a pair of first grooves, a pair of second grooves, and a pair of second grooves formed on the outer peripheral surface of the rotor core and extending parallel to the central axis at one magnetic pole, respectively. It includes a pair of third grooves. In the cross section of the rotor core orthogonal to the central axis, the boundary between the adjacent magnetic poles and the axis extending in the radial direction through the central axis are electrically separated from the q-axis by 90 degrees. When the axis is the d-axis, the first magnet embedding hole has a first magnet loading region in which the first permanent magnet is loaded and a first inner circumference extending from the first magnet loading region toward the d-axis side. It has a side gap and a first outer peripheral side gap extending from the first magnet loading region to the vicinity of the outer peripheral surface, and the rotor core is formed between the two first inner peripheral side gaps. It has a first bridge portion and a second bridge portion formed between each of the first outer peripheral side gaps and the outer peripheral surface. The second magnet embedding hole is located on the inner peripheral side of the first magnet loading region and is located on the second magnet loading region on which the second permanent magnet is loaded and from the second magnet loading region to the d-axis side. The second inner peripheral side gap located on the central axis side with respect to the first inner peripheral side gap, and the first outer peripheral side gap overhanging from the second magnet loading region to the vicinity of the outer peripheral surface. The rotor core has a second outer peripheral side gap located between the q-axis and the third bridge portion formed between the two second inner peripheral side gaps, and each of the first. 2. It has a fourth bridge portion formed between the outer peripheral side gap and the outer peripheral surface. The pair of first grooves, the pair of second grooves, and the pair of third grooves are each provided line-symmetrically with respect to the d-axis, and the first groove is located adjacent to the d-axis, and the first groove is located. The two grooves are provided between the first groove and the second bridge portion, the third groove is provided between the second bridge portion and the third bridge portion, and the width of the first groove is wide. The electric angle between the center of the direction and the d-axis is 3 to 6 degrees, and the electric angle between the center in the width direction of the second groove and the d-axis side end of the second bridge portion is 6 to 11 degrees. The electrical angle θ3 between the center in the width direction of the third groove and the d-axis side end of the fourth bridge portion is 9.5 to 12.5 degrees.

FIG. 1 is a cross-sectional view showing a permanent magnet type rotary electric machine according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing one magnetic pole portion of the rotor of the rotary electric machine. FIG. 3 is a diagram showing the relationship between the position of the first groove of the rotor and the torque ripple. FIG. 4 is a diagram showing the relationship between the position of the second groove of the rotor and the torque ripple. FIG. 5 is a diagram showing the relationship between the position of the third groove of the rotor and the torque ripple.

Hereinafter, embodiments will be described with reference to the drawings. It should be noted that the same reference numerals are given to common configurations throughout the embodiment, and duplicate description will be omitted. In addition, each figure is a schematic view for facilitating the understanding of the embodiment, and the shape, dimensions, ratio, etc. of the embodiment are different from those of the actual device, but these are based on the following explanation and known techniques. The design can be changed as appropriate.

FIG. 1 is a cross-sectional view showing a part of a permanent magnet type rotary electric machine according to an embodiment, and FIG. 2 is a cross-sectional view showing an enlarged portion of one magnetic pole of a rotor.
As shown in FIG. 1, the rotary electric machine 10 is configured as, for example, an inner rotor type rotary electric machine, and has an annular or cylindrical stator 12 supported by a fixing frame (not shown) and a central axis C inside the stator. It is provided with a rotor 14 that is rotatable around the stator and is supported coaxially with the stator 12. The rotary electric machine 10 is suitably applied to a drive motor or a generator in, for example, a hybrid electric vehicle (HEV) or an electric vehicle (EV).

The stator 12 includes a cylindrical stator core 16 and an armature winding 18 wound around the stator core 16. The stator core 16 is formed by laminating a large number of magnetic materials, for example, a large number of annular electromagnetic steel plates such as silicon steel, in a concentric manner. A plurality of slots 20 are formed in the inner peripheral portion of the stator core 16. The plurality of slots 20 are arranged at equal intervals in the circumferential direction. Each slot 20 opens on the inner peripheral surface of the stator core 16 and extends in the radial direction from the inner peripheral surface. Further, each slot 20 extends over the entire length of the stator core 16 in the axial direction. By forming the plurality of slots 20, the inner peripheral portion of the stator core 16 constitutes a plurality of (for example, 48 in the present embodiment) stator teeth 21 facing the rotor 14. Armature windings 18 are embedded in the plurality of slots 20 and wound around the stator teeth 21. By passing an electric current through the armature winding 18, a predetermined interlinkage magnetic flux is formed in the stator 12 (stator teeth 21).

As shown in FIGS. 1 and 3, the rotor 14 is fixed to a cylindrical shaft (rotating shaft) 22 whose ends are rotatably supported by bearings (not shown) and substantially at the center of the shaft 22 in the axial direction. It has a cylindrical rotor core 24 and a plurality of permanent magnets 26 embedded in the rotor core 24. The rotor 14 is coaxially arranged with a slight gap (air gap) G inside the stator 12. That is, the outer peripheral surface of the rotor 14 faces the inner peripheral surface of the stator 12 with a slight gap. In one example, the gap length δ of the gap G is 0.6 mm. The rotor core 24 has an inner hole 25 formed coaxially with the central axis C. The shaft 22 is inserted and fitted into the inner hole 25 and extends coaxially with the rotor core 24. The rotor core 24 is configured as a laminated body in which a large number of magnetic materials, for example, a large number of annular electromagnetic steel plates 24a such as silicon steel are laminated concentrically. The shaft 22 and the rotor core 24 are rotatably supported around the central axis C.

In this embodiment, the rotor 14 has a plurality of magnetic poles, for example, eight magnetic poles. In the cross section of the rotor 14 orthogonal to the central axis C, the boundary between the magnetic poles adjacent to each other in the circumferential direction and the axis extending radially or radially through the central axis C are electrically connected to the q-axis and the q-axis. The axes magnetically separated by 90 ° are referred to as the d-axis (magnetic pole center axis). Here, the direction in which the interlinkage magnetic flux formed by the stator 12 easily flows is referred to as the q-axis. The d-axis and the q-axis are provided alternately in the circumferential direction of the rotor core 24 and in a predetermined phase. One magnetic pole portion of the rotor core 24 refers to a region between two adjacent q axes (a circumferential angle region of 1/8 circumference). The center of one magnetic pole in the circumferential direction is the d-axis.

A pair of first permanent magnets M1 and a pair of second permanent magnets M2 are embedded in the rotor core 24 for each magnetic pole. A pair of first magnet embedding holes (first void layer or first flux barrier) (hereinafter, first) accommodating two first permanent magnets M1 on both sides of each d-axis in the circumferential direction of the rotor core 24. 34A (referred to as an embedding hole) is formed. A pair of second magnet embedding holes (second void layer or second flux barrier) (hereinafter referred to as second embedding holes) 34B for accommodating the two second permanent magnets M2 are formed on both sides of the d-axis. The second embedding hole 34B is provided on the inner peripheral side of the rotor core 24 with a distance from the first embedding hole 34A.

At each magnetic pole, the first embedded hole 34A is provided between the d-axis and the q-axis and extends from the vicinity of the d-axis to the vicinity of the outer peripheral surface of the rotor core 24. The second embedding hole 34B is provided between the d-axis and the q-axis at intervals on the inner peripheral side of the rotor core 24 with respect to the first embedding hole 34A, from the vicinity of the d-axis to the vicinity of the outer peripheral surface. It is postponed. In the present embodiment, the two first embedded holes 34A are formed line-symmetrically with respect to the d-axis, and the two second embedded holes 34B are formed line-symmetrically with respect to the d-axis.
The two first permanent magnets M1 are inserted and arranged in the first embedding holes 34A, respectively, and are fixed to the rotor core 24 by, for example, an adhesive or the like. The two second permanent magnets M2 are inserted and arranged in the second embedded hole 34B, respectively, and are fixed to the rotor core 24 by, for example, an adhesive or the like.

As shown in FIG. 2, the first embedding hole 34A and the second embedding hole 34B extend axially through the rotor core 24. The first embedding hole 34A has a substantially rectangular cross-sectional shape and is inclined with respect to the d-axis. When viewed in cross section of the rotor core 24 orthogonal to the central axis C, the two first embedded holes 34A are arranged side by side in a substantially V shape, for example. That is, the inner peripheral side ends (inner peripheral side ends) of the two first embedded holes 34A are adjacent to the d-axis and face each other with a slight gap. In the rotor core 24, a narrow magnetic path narrow portion (first bridge portion) B1 is formed between the inner peripheral side ends of the two first embedding holes 34A. The outer peripheral end (outer peripheral end) of the two first embedded holes 34A is separated from the d-axis along the circumferential direction of the rotor core 24 and is located near the outer peripheral surface of the rotor core 24. .. In the rotor core 24, a narrow magnetic path narrow portion (second bridge portion) B2 is formed between the outer peripheral side end of each first embedding hole 34A and the outer peripheral edge of the rotor core 24. As described above, the outer peripheral side ends of the two first embedding holes 34A are located closer to the outer peripheral surface side of the rotor core 24 than the inner peripheral side end, and from the d-axis toward the outer peripheral side end from the inner peripheral side end. It is arranged so that the distance between them gradually increases.

The first permanent magnet M1 is formed in a flat plate shape having a rectangular cross section, for example, and has a length substantially equal to the axial length of the rotor core 24. The first permanent magnet M1 is inserted into the first magnet embedding hole 34A and is embedded over almost the entire length of the rotor core 24. The cross section of each first permanent magnet M1 has a pair of long sides facing each other in parallel and a pair of short sides facing each other. The first permanent magnet M1 is magnetized in the direction perpendicular to the long side.

Each of the first embedded holes 34A is formed from both ends of a rectangular magnet loading region 35a corresponding to the cross-sectional shape of the first permanent magnet M1 and a longitudinal direction of the magnet loading region 35a (a direction perpendicular to the magnetization direction of the permanent magnet M1). It has two overhanging voids (inner peripheral side void 35b and outer peripheral side void 35c), and a pair of locking protrusions 35d protruding into the first embedding hole 34A at both ends in the longitudinal direction of the magnet loading region 35a. doing. The pair of locking convex portions 35d are provided at diagonal positions of the magnet loading region 35a.
The inner peripheral side gap 35b projects from the magnet loading region 35a toward the d-axis. The inner peripheral side gaps 35b of the two first embedding holes 34A are arranged so as to face each other with the d-axis and the first bridge portion B1 interposed therebetween. The outer peripheral side gap 35c projects from the magnet loading region 35a toward the outer peripheral surface of the rotor core 24. A second bridge portion B2 is formed between the outer peripheral side gap 35c and the outer peripheral edge of the rotor core 24.
The inner peripheral side gap 35b and the outer peripheral side gap 35c function as a flux barrier that suppresses magnetic flux leakage from both ends of the first permanent magnet M1 in the longitudinal direction to the rotor core 24, and also reduces the weight of the rotor core 24. Contribute.

The first permanent magnet M1 is loaded in the magnet loading region 35a and fixed to the rotor core 24 with an adhesive or the like. The pair of corner portions of the first permanent magnet M1 are in contact with the locking convex portions 35d, respectively. As a result, the first permanent magnet M1 is positioned within the magnet loading region 35a. The two first permanent magnets M1 located on both sides of the d-axis are arranged side by side in a substantially V shape. That is, the two first permanent magnets M1 are arranged so that the distance from the d-axis gradually increases from the inner peripheral side end to the outer peripheral side end. The two first permanent magnets M1 located on both sides of each d-axis are arranged so that the magnetization directions are the same. Further, the two first permanent magnets M1 located on both sides of each q-axis are arranged so that the magnetization directions are opposite to each other.

On the other hand, the pair of second embedded holes (second flux barrier) 34B are provided on the inner peripheral side of the rotor core 24 with respect to the first embedded holes 34A. The second embedded hole 34B has a substantially rectangular cross-sectional shape and is inclined with respect to the d-axis. When viewed in a cross section orthogonal to the central axis C of the rotor core 24, the two second embedded holes 34B are arranged side by side in a substantially V shape. That is, the inner peripheral side ends (d-axis side ends) of the two second embedded holes 34B are adjacent to the d-axis and face each other with a slight gap. The inner peripheral side end of the second embedded hole 34B is located between the inner peripheral side end of the first embedded hole 34A and the central axis C. In the rotor core 24, a narrow magnetic path narrow portion (third bridge portion) B3 is formed between the inner peripheral side ends of the two second embedded holes 34B. The outer peripheral side end (the outer peripheral surface side end) of the second embedding hole 34B is separated from the d-axis along the circumferential direction of the rotor core 24, and is near the outer peripheral surface of the rotor core 24 and near the q-axis. positioned. The outer peripheral end of the second embedding hole 34B is located between the outer peripheral end of the first embedding hole 34A and the q-axis. In the rotor core 24, a narrow magnetic path narrow portion (fourth bridge portion) B4 is formed between the outer peripheral side end of each second embedded hole 34B and the outer peripheral edge of the rotor core 24. As described above, the outer peripheral side ends of the two second embedding holes 34B are located closer to the outer peripheral surface side of the rotor core 24 than the inner peripheral side end, and from the d-axis toward the outer peripheral side end from the inner peripheral side end. It is arranged so that the distance between them gradually increases.

The second permanent magnet M2 is formed in a flat plate shape having a rectangular cross section, for example, and has a length substantially equal to the axial length of the rotor core 24. The second permanent magnet M2 is inserted into the second magnet embedding hole 34B and is embedded over almost the entire length of the rotor core 24. The cross section of each second permanent magnet M2 has a pair of long sides facing each other in parallel and a pair of short sides facing each other. The second permanent magnet M2 is magnetized in the direction perpendicular to the long side. In the present embodiment, the second permanent magnet M2 has a width (longitudinal dimension of the cross section) larger than that of the first permanent magnet M1.

Each of the second embedded holes 34B is formed from both ends of a rectangular magnet loading region 37a corresponding to the cross-sectional shape of the second permanent magnet M2 and a longitudinal direction of the magnet loading region 37a (a direction perpendicular to the magnetization direction of the permanent magnet M1). It has an overhanging inner peripheral side gap 37b and an outer peripheral side gap 37c, and a pair of locking protrusions 37d protruding into the second embedding hole 34B at both ends in the longitudinal direction of the magnet loading region 37a. A pair of locking protrusions 37d are provided at both ends of one long side of the magnet loading region 37a.
The inner peripheral side gap 37b projects from the magnet loading region 37a toward the d-axis. The inner peripheral side gaps 37b of the two second embedding holes 34B are arranged so as to face each other with the d-axis and the third bridge portion B3 interposed therebetween. The outer peripheral side gap 37c projects from the magnet loading region 37a toward the outer peripheral surface of the rotor core 24. A fourth bridge portion B4 is formed between the outer peripheral side gap 37c and the outer peripheral edge of the rotor core 24.
The inner peripheral side gap 37b and the outer peripheral side gap 37c function as a flux barrier that suppresses magnetic flux leakage from both ends of the second permanent magnet M2 in the longitudinal direction to the rotor core 24, and also reduces the weight of the rotor core 24. Contribute.

The second permanent magnet M2 is loaded in the magnet loading region 37a and fixed to the rotor core 24 with an adhesive or the like. The pair of corner portions of the second permanent magnet M2 are in contact with the locking convex portions 37d, respectively. As a result, the second permanent magnet M2 is positioned within the magnet loading region 37a. The two second permanent magnets M2 located on both sides of the d-axis are arranged side by side in a substantially V shape. That is, the two second permanent magnets M2 are arranged so that the distance from the d-axis gradually increases from the inner peripheral side end to the outer peripheral side end. The two second permanent magnets M2 located on both sides of each d-axis are arranged so that the magnetization directions are the same. Further, the two second permanent magnets M2 located on both sides of each q-axis are arranged so that the magnetization directions are opposite to each other.

By arranging the first permanent magnet M1 and the second permanent magnet M2 as described above, the rotary electric machine 10 has the front and back sides of the north and south poles of the first and second permanent magnets M1 and M2 for each adjacent magnetic pole. A permanent magnet type rotary electric machine 10 wound with a single-layer distributed winding is configured in 48 slots with 8 poles (4 pole pairs) arranged alternately.

A plurality of void holes (cavities) 40 are formed in the rotor core 24. The gap holes 40 extend axially through the rotor core 24, respectively. The gap holes 40 are located substantially in the radial direction of the rotor core 24 on the q-axis, and are provided between the two second embedded holes 34B of the adjacent magnetic poles. The gap 40 has a polygonal, for example, triangular cross-sectional shape. Each of the gap holes 40 functions as a flux barrier that makes it difficult for the magnetic flux to pass through, and regulates the flow of the interlinkage magnetic flux of the stator 12 and the flow of the magnetic flux of the permanent magnets M1 and M2. Further, by forming the gap holes 40, the weight of the rotor core 24 can be reduced.

As shown in FIG. 2, the rotor core 24 further includes a plurality of grooves provided on the outer peripheral surface. Six grooves are provided on the outer peripheral surface per magnetic pole. That is, the rotor core 24 includes a pair of first grooves G1, a pair of second grooves G2, and a pair of third grooves G3 provided on the outer peripheral surface at one magnetic pole. Each groove G1 to G3 extends parallel to the central axis C over the entire length of the rotor core 24 in the axial direction. The pair of first grooves G1, the pair of second grooves G2, and the pair of third grooves G3 are formed and arranged line-symmetrically with respect to the d-axis, respectively.

The first groove G1 is provided closest to the d-axis. The first groove G1 projects from the outer peripheral surface toward the central axis C side. In the embodiment, the first groove G1 is formed in a groove having an arcuate bottom surface. The first groove G1 has a width W1 in the circumferential direction, and the bottom surface of the first groove G1 is an arc surface having an apex in the center in the width direction, and the position of the apex is the deepest groove. The width W1 of the first groove G1 is about 2.9 to 4.3 degrees in electrical angle, and the depth d1 is about 0.5 × δ (gap length) to about 0.9 × δ mm. The first groove G1 is provided at a position where the angle (electrical angle) θ1 between the apex of the first groove G1 and the d-axis is 3 to 6 degrees.

The second groove G2 is provided between the first groove G1 and the second bridge portion B2 on the outer peripheral surface. The second groove G2 projects from the outer peripheral surface toward the central axis C side. In the embodiment, the second groove G2 is formed in a groove having an arcuate bottom surface. The second groove G2 has a width W2 in the circumferential direction, and the bottom surface of the second groove G2 is an arc surface having an apex in the center in the width direction, and the position of the apex is the deepest groove. The width W2 of the second groove G2 is about 3.5 to 5.3 degrees in electrical angle, and the depth d2 is about 0.1 × δ to 0.5 × δ mm. The second groove G2 is provided at a position where the angle (electrical angle) θ2 between the apex of the second groove G2 and the d-axis side end of the second bridge portion B2 is 9.5 to 12.5 degrees. ..

The third groove G3 is provided on the outer peripheral surface between the second bridge portion B2 and the fourth bridge portion B4 in the vicinity of the fourth bridge portion B4. The third groove G3 projects from the outer peripheral surface toward the central axis C side. In the embodiment, the third groove G3 is formed in a groove having an arcuate bottom surface. The third groove G3 has a width W3 in the circumferential direction, and the bottom surface of the third groove G3 is an arc surface having an apex in the center in the width direction, and the position of the apex is the deepest groove. The width W3 of the third groove G3 is about 9.7 to 14.5 degrees in electrical angle, and the depth d3 is about 0.3 × δ to 0.7 × δ mm. The third groove G3 is provided at a position where the angle (electrical angle) θ3 between the apex of the third groove G2 and the d-axis side end of the fourth bridge portion B4 is 6 to 11 degrees.

The first groove G1, the second groove G2, and the third groove G3 are formed in the relationship of W1 <W2 <W3 and d1 ≦ d2 ≦ d3. Further, only the first, second, and third grooves G1, G2, and G3 are formed on the outer peripheral surface of the rotor core 24, and no other grooves are provided. That is, a continuous arc-shaped outer peripheral surface R1 exists between the pair of first grooves G1, and a continuous arc-shaped outer peripheral surface R2 exists between each first groove G1 and the second groove G2. A continuous arcuate outer peripheral surface R3 exists between the two grooves G2 and the third groove G3, and a continuous arcuate outer peripheral surface R4 exists between each third groove G3 and the q-axis.
Each of the first groove G1, the second groove G2, and the third groove G3 is not limited to a groove having an arc-shaped bottom surface, for example, a V-shaped bottom surface or a groove having a bottom surface having no discontinuity. May be. Further, the groove is not limited to the groove whose deepest portion is located at the center position in the width direction of the groove, and may be a groove whose deepest portion is deviated to one side in the width direction.

As described above, by providing the first, second, and third grooves G1, G2, and G3 on the outer peripheral surface of the rotor core 24, the rotor is provided even when the two layers of permanent magnets M1 and M2 are provided. It is possible to make the magnetic flux density distribution in the circumferential direction uniform and reduce torque ripple.
FIG. 3 is a diagram showing the relationship between the formation position (angle θ1) of the first groove G1 and the torque ripple reduction, and FIG. 4 is a diagram showing the relationship between the formation position (angle θ2) of the second groove G2 and the torque ripple reduction. FIG. 5 is a diagram showing the relationship between the formation position (angle θ3) of the third groove G1 and the reduction of torque ripple.
From FIG. 3, it can be seen that the torque ripple is reduced to about 26 to 33% at the formation position of the first groove G1 when the angle θ1 is in the range of about 3 to 6 degrees. From FIG. 4, it can be seen that the formation position of the second groove G2 is such that the angle θ2 is in the range of about 9.5 to 12.5 degrees and the torque ripple is reduced to about 27 to 30%. From FIG. 5, it can be seen that the formation position of the third groove G3 is such that the angle θ3 is in the range of about 6 to 11 degrees and the torque ripple is reduced to about 28 to 55%.

As described above, according to the present embodiment, even when the two layers of permanent magnets M1 and M2 are provided, the rotating electric machine capable of making the magnetic flux density distribution in the circumferential direction of the rotor uniform and reducing torque ripple. Rotor can be obtained. By reducing the torque ripple, it is possible to realize a rotary electric machine with reduced vibration and noise.

The present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the components can be modified and embodied without departing from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.
For example, the number of magnetic poles, dimensions, shape, and the like of the rotor are not limited to the above-described embodiment, and can be variously changed according to the design. The cross-sectional shapes of the inner peripheral side voids, the outer peripheral side voids, and the void holes are not limited to the shapes of the embodiments, and various shapes can be selected.

10 ... Rotor, 12 ... Stator, 14 ... Rotor, 16 ... Stator iron core,
18 ... armature winding, 20 ... slot, 22 ... rotating shaft, 24 ... rotor core,
34A ... 1st magnet embedding hole (1st flux barrier),
34B ... 2nd magnet embedding hole (2nd flux barrier),
35a, 37a ... Magnet loading area, 35b, 37b ... Inner peripheral gap,
35c, 37c ... Outer peripheral gap, M1 ... 1st permanent magnet, M2 ... 2nd permanent magnet,
B1 ... 1st bridge part, B2 ... 2nd bridge part, B3 ... 3rd bridge part,
B4 ... 4th bridge, G1 ... 1st groove, G2 ... 2nd groove, G3 ... 3rd groove, G4 ... 4th groove

Claims (5)

A shaft that rotates around the central axis and
A rotor core fixed to the shaft and having a plurality of magnetic poles arranged in the circumferential direction,
A pair of first magnet embedding holes and a pair of second magnet embedding holes formed for each magnetic pole of the rotor core,
A pair of first permanent magnets loaded and placed in the pair of first magnet embedding holes,
A pair of second permanent magnets loaded and placed in the pair of second magnet embedding holes,
One magnetic pole includes a pair of first grooves, a pair of second grooves, and a pair of third grooves formed on the outer peripheral surface of the rotor core and extending in parallel with the central axis.
In the cross section of the rotor core orthogonal to the central axis,
When the boundary between the adjacent magnetic poles and the axis extending in the radial direction through the central axis are the q-axis, and the axis electrically 90 degrees away from the q-axis is the d-axis.
The first magnet embedding hole includes a first magnet loading region in which the first permanent magnet is loaded, a first inner peripheral side gap protruding from the first magnet loading region toward the d-axis side, and the first magnet. The rotor core has a first outer peripheral side gap extending from the loading region to the vicinity of the outer peripheral surface, and the rotor core has a first bridge portion formed between the two first inner peripheral side gaps and the said. It has a second bridge portion formed between each first outer peripheral side gap and the outer peripheral surface, and has.
The second magnet embedding hole is located on the inner peripheral side of the first magnet loading region and is located on the second magnet loading region on which the second permanent magnet is loaded and from the second magnet loading region to the d-axis side. The second inner peripheral side gap located on the central axis side with respect to the first inner peripheral side gap, and the first outer peripheral side gap overhanging from the second magnet loading region to the vicinity of the outer peripheral surface. The rotor core has a second outer peripheral side gap located between the q-axis and the third bridge portion formed between the two second inner peripheral side gaps, and each of the first. 2 It has a fourth bridge portion formed between the outer peripheral side gap and the outer peripheral surface, and has.
The pair of first grooves, the pair of second grooves, and the pair of third grooves are each provided line-symmetrically with respect to the d-axis, and the first groove is located adjacent to the d-axis, and the first groove is located. The two grooves are provided between the first groove and the second bridge portion, and the third groove is provided between the second bridge portion and the third bridge portion.
The electric angle between the center in the width direction of the first groove and the d-axis is 3 to 6 degrees, and the electric angle between the center in the width direction of the second groove and the d-axis side end of the second bridge portion. Is 6 to 11 degrees, and the electric angle θ3 between the center in the width direction of the third groove and the d-axis side end of the fourth bridge portion is 9.5 to 12.5 degrees. Claim 1 in which W1 <W2 <W3, where W1 is the circumferential width of the first groove, W2 is the circumferential width of the second groove, and W3 is the circumferential width of the third groove. The rotor of the rotating electric machine described. The rotary electric machine according to claim 1 or 2, wherein when the depth of the first groove is d1, the depth of the second groove is d2, and the depth of the third groove is d3, d1 ≦ d2 ≦ d3. Rotor. On the outer peripheral surface of the rotor core, between the pair of first grooves, between the first groove and the second groove, between the second groove and the third groove, and between the third groove and the q. The rotor of a rotary electric machine according to any one of claims 1 to 3, wherein no other groove is provided between the rotor and the shaft. The pair of first permanent magnets is formed in a rectangular shape having a pair of long sides facing each other and a pair of short sides facing each other, and has an inner peripheral side end adjacent to the d-axis and an outer peripheral surface adjacent to the outer peripheral surface. It has a side end and is arranged line-symmetrically with respect to the d-axis, and the long side is on the d-axis so that the distance from the d-axis gradually increases from the inner peripheral side end to the outer peripheral side end. Arranged at an angle,
The pair of second permanent magnets are formed in a rectangular shape having a pair of long sides facing each other and a pair of short sides facing each other, and are located closer to the central axis side than the inner peripheral side ends of the first permanent magnets. It has an inner peripheral end adjacent to the d-axis and an outer peripheral end adjacent to the outer peripheral surface located on the q-axis side of the outer peripheral end of the first permanent magnet, and is a line with respect to the d-axis. Claims 1 to 4 are arranged symmetrically, and the long side is inclined with respect to the d-axis so that the distance from the d-axis gradually increases from the inner peripheral side end to the outer peripheral side end. The rotor of the rotary electric machine according to any one of the above items.

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