JP2021048685A - Rotor of rotary electric machine - Google Patents

Abstract

To provide a rotor of a rotary electric machine capable of obtaining high torque.SOLUTION: A rotor of a rotary electric machine includes a rotor core and permanent magnets disposed in a gap layer formed in each magnetic pole. The gap layer includes a magnet loading region in which the permanent magnet is housed, an inner circumferential side magnetic gap, and an outer circumferential side magnetic gap. In the permanent magnet, an inner end m1 and an outer end m2 of the first long side are located on a q-axis flux line fd (θq3), and the inner end m1 is located at an intersection of a d-axis flux line fd (θd1) and the q-axis flux line fd (θq3). One side edge of the inner peripheral side magnetic gap extends from the inner end m4 of the permanent magnet to an intersection m5 of the q-axis flux line fd (θq1) and the d-axis flux line fd (θq2), and extends from the intersection m5 toward the d-axis side. The θq2 defining the intersection m5 satisfies conditional expression of -3/P<(θd2-θd1)<9/P.SELECTED DRAWING: Figure 3

Description

An embodiment of the present invention relates to a rotor of a permanent magnet type rotary electric machine.

In recent years, due to remarkable research and development of permanent magnets, permanent magnets having a high magnetic energy product have been developed, and permanent magnet type rotary electric machines using such permanent magnets are being applied as electric motors or generators for trains and automobiles. Usually, a permanent magnet type rotary electric machine includes a cylindrical stator and a cylindrical rotor rotatably supported inside the stator. The rotor includes a rotor core and a plurality of permanent magnets embedded in the rotor core.

In such a permanent magnet type rotary electric machine, a technique for reducing iron loss in the rotor core has been proposed by providing a plurality of layers composed of a void layer (flux barrier) and a permanent magnet at each magnetic pole. ing. When the void layer is a single layer and has a permanent magnet inside, a technique is known in which a high torque is obtained by making the layer shape along the flux line due to the armature reaction. Further, when the void layer is a plurality of layers and includes a void layer having no permanent magnet inside, a high torque can be obtained by forming each layer along the flux line.

Japanese Unexamined Patent Publication No. 2012-178921 Japanese Unexamined Patent Publication No. 2012-178922

However, in a rotor having a void layer, if the void layer and the rotor core are not properly shaped and arranged, the magnetic polarity of the rotor is lowered and the reluctance torque is lowered.
The present invention has been made in view of the above points, and an object of the present invention is to provide a rotor of a rotating electric machine capable of realizing a high torque without increasing the amount of magnets.

According to the embodiment, the rotor of the rotary electric machine is provided in a plurality of magnetic poles arranged in a circumferential direction around the central axis, and in the radial direction through the circumferential end of the magnetic pole and the central axis. When the extending axis is the q-axis and the axis electrically 90 degrees apart from the q-axis in the circumferential direction is the d-axis, the inner peripheral side magnetism facing the d-axis via the first bridge portion is used. A void layer including an outer peripheral side magnetic gap facing the outer peripheral surface via the gap and a second bridge portion, and a magnet loading region located between the inner peripheral side magnetic gap and the outer peripheral side magnetic gap is provided. It has a rotor core, a first long side having an inner end m1 on the d-axis side and an outer end m2 on the outer peripheral surface side, an inner end m4 on the d-axis side, and an outer end m3 on the outer peripheral surface side. It is formed in a rectangular cross-sectional shape located on the q-axis side with respect to the first long side and has a second long side facing the first long side at intervals, and is arranged in the magnet loading region. It is equipped with a permanent magnet. In the cross section of the rotor core orthogonal to the central axis, R: the radius of the circumscribed circle centered on the central axis circumscribing the outer periphery of the rotor core, r: the d-axis centered on the central axis. , Radical coordinates of the polar coordinate system sandwiched between the q-axis, θ: The d-axis with the central axis as the center point, and the angular coordinates of the polar coordinate system sandwiched between the q-axis (the d-axis with reference to the q-axis). The direction toward is positive), p: the number of pole pairs (number of magnetic poles / 2), θd: the angular coordinates of an arbitrary point on the circumscribed circle, θq: the angular coordinates of an arbitrary point on the circumscribed circle. The d-axis flux line passing through the coordinates (R, θd) is defined by the formula (1) described later, the q-axis flux line passing through the coordinates (R, θq) is defined by the formula (2) described later, and the d-axis flux line is defined. The coordinates (rdq, θdq) of the intersection of the q-axis flux line and the q-axis flux line are defined by the formula (3) described later, and the angular coordinates of any three points set on the circumscribed circle are θ _q1 , θ _q2 , and θ _q3 (. θ _q3 > θ _q2 > θ _q1 ), and the angular coordinates of any two points set on the circumscribed circle are θ _d1 , θ _d2 (θ _d2 > θ _d1 > θ _q3 ), and the angular coordinates θ _q1 and θ. _The q-axis flux lines passing through the respective points of q2 and θ _{q3 are the q-axis flux line fd (θ q1} ), the q-axis flux line fd (θ _q2 ), and the q-axis flux line fd (θ _q3 ). _Assuming that the _{d-axis flux lines passing through the points d1 and θ d2} are the d-axis flux line fd (θ _d1 ) and the d-axis flux line fd (θ _d2 ), respectively.
The magnet loading region is provided in a region surrounded by the q-axis flux line fd (θ _q2 ) and the q-axis flux line fd (θ _q3 ), and the permanent magnet is provided at the inner end m1 of the first long side. And the outer end m2 is located on the q-axis flux line fd (θ _q3 ), and the inner end m1 is at the intersection of the q-axis flux line fd (θ _q3 ) and the d-axis flux line fd (θ _d1 ). The inner peripheral side magnetic gaps are arranged so as to be located, and the q-axis flux line fd (θ _q1 ) and the d-axis flux line fd (θ _d2 ) are formed from the inner end m4 of the second long side of the permanent magnet. _{The angular coordinate θ d2,} which extends to the intersection m5 with and extends from the intersection m5 to the d-axis side and defines the intersection m5, satisfies the conditional expression (4) described later.

FIG. 1 is a cross-sectional view of a permanent magnet type rotary electric machine according to an embodiment. FIG. 2 is a cross-sectional view showing an enlarged view of one magnetic pole portion of the rotary electric machine. FIG. 3 is a net diagram showing magnetic flux lines for setting the shape and arrangement of the void layer (flux barrier) in the rotor of a rotary electric machine. FIG. 4 is a diagram showing changes in generated torque due to differences in the shape of the void layer. FIG. 5 is a cross-sectional view showing one magnetic pole portion of the rotary electric machine according to the modified example.

Hereinafter, embodiments will be described with reference to the drawings. In addition, 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 of a permanent magnet type rotary electric machine according to an embodiment.
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 traction motor, a drive motor, or a generator in, for example, a railroad vehicle, 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, 36 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).

The rotor 14 includes a cylindrical shaft (rotating shaft) 22, a cylindrical rotor core 24 coaxially fixed to a substantially central portion in the axial direction of the shaft 22, and a plurality of rotors 14 embedded in the rotor core 24. It has a permanent magnet M and. The shaft 22 is rotatably supported around the central axis C by bearings (not shown). The rotor 14 is coaxially arranged with a slight gap (air gap) inside the stator 12. That is, the outer peripheral surface of the rotor core 24 faces the inner peripheral surface of the stator 12 with a slight gap. 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 composed of a laminated body in which a large number of magnetic materials, for example, a large number of annular electromagnetic steel plates such as silicon steel are laminated concentrically.

In this embodiment, the rotor 14 is set to a plurality of magnetic poles, for example, 8 magnetic poles. That is, the rotor core 24 has eight magnetic poles arranged in the circumferential direction around the central axis C. In the cross section of the rotor core 24 orthogonal to the central axis C, the axis extending radially from the central axis C between the adjacent magnetic poles is the q-axis, and the axis electrically separated from the q-axis by 90 ° ( The axis that is electrically and magnetically orthogonal to the q-axis) is referred to as the d-axis. Here, the q-axis is the direction in which the interlinkage magnetic flux formed by the stator 12 easily flows. 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 means a region between two adjacent q-axes (a circumferential angle region of 1/6 circumference). Therefore, the rotor core 24 is configured to have 6 poles (magnetic poles). The center of one magnetic pole in the circumferential direction is the d-axis.

A plurality of permanent magnets M, for example, two permanent magnets M are embedded in the rotor core 24 for each magnetic pole. A pair of embedded holes (void layers or flux barriers) 34A for accommodating permanent magnets M are formed on both sides of each d-axis in the circumferential direction of the rotor core 24. At each magnetic pole, the embedding 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 periphery of the rotor core 24. The two permanent magnets M are inserted and arranged in the embedding holes 34A, respectively, and are fixed to the rotor core 24 by, for example, an adhesive or the like. In the present embodiment, the two embedding holes 34A and the two permanent magnets M are formed and arranged symmetrically with respect to the d-axis.

FIG. 2 is an enlarged cross-sectional view showing a part of the rotor (one magnetic pole portion).
As shown, the embedding hole 34A extends axially through the rotor core 24. The embedding hole 34A has a substantially rectangular cross-sectional shape, and each is inclined by an angle smaller than 90 degrees 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 embedding holes 34A are arranged side by side in a substantially V shape, for example. That is, one end of each of the two embedding holes 34A on the inner peripheral side is adjacent to the d-axis and faces each other with a slight gap. In the rotor core 24, a narrow magnetic path narrow portion (first bridge portion) V1 is formed between the inner ends (ends on the d-axis side) of the two embedding holes 34A. The outer end (end on the outer peripheral surface side) of the embedding hole 34A is located on the outer peripheral side of the rotor core 24 with respect to the inner end, and is located near the outer periphery of the rotor core 24. The outer end of the embedding hole 34A is separated from the inner end in the circumferential direction from the d-axis and is located near the q-axis. In the rotor core 24, a narrow magnetic path narrow portion (second bridge portion) V2 is formed between the outer end of the embedding hole 34A and the outer peripheral surface of the rotor core 24. In this way, the two embedding holes 34A are arranged so that the outer end is located on the outer peripheral side of the inner end and the distance from the d-axis gradually increases from the inner end to the outer end. ..

The embedded hole (void layer) 34A has a rectangular magnet loading region 35a corresponding to the cross-sectional shape of the permanent magnet M, an inner peripheral side magnetic gap 35b extending from both ends in the longitudinal direction of the magnet loading region 35a, and an outer peripheral side, respectively. It has a magnetic gap of 35c.
The magnet loading region 35a is a linear second side located on the inner peripheral side of the linear first side edge 36a and the first side edge 36a and facing the first side edge 36a in parallel through a gap. It is formed between the edge 36b and the edge 36b. As described above, the first side edge 36a and the second side edge 36b are inclined at an angle smaller than 90 degrees with respect to the d-axis.

The inner peripheral side magnetic gap 35b extends from the inner end of the magnet loading region 35a toward the d-axis. The inner peripheral side magnetic gap 35b is formed by a first side edge 44a, a second side edge 44b, and a third side edge 44c. The first side edge 44a extends from one end (d-axis side end) of the magnet loading region 35a first side edge 36a or the inner end m1 of the first long side 37a of the permanent magnet M to the vicinity of the d-axis. ing. The second side edge 44b is the center of the rotor core 24 from one end (d-axis side end) of the magnet loading region 35a second side edge 36b, that is, from the inner end m4 of the second long side 37b of the permanent magnet M. It extends toward the axes C and d to the vicinity of the d axis. The third side edge 44c straddles the extending end of the first side edge 44a and the extending end of the second side edge 44b, and extends substantially parallel to the d-axis. The inner peripheral side magnetic gaps 35b of the two embedding holes 34A are arranged so that the third side edges 44c are opposed to each other with the d-axis and the bridge portion V1 interposed therebetween. The corners at both ends of the third side edge 44c may be rounded in an arc shape. Further, the second inner edge 44b has a linear shape that is bent in the middle portion, but the present invention is not limited to this, and a gently curved side edge may be used.

The outer peripheral side magnetic gap 35c is formed by a first side edge 46a, a second side edge 46b, and a third side edge 46c. The first side edge 46a extends from the other end of the first side edge 36a of the magnet loading region 35a (the end on the outer peripheral surface side of the rotor core 24) toward the outer peripheral surface of the rotor core 24. The second side edge 46b extends from the other end of the second side edge 36b of the magnet loading region 35a (the end on the outer peripheral surface side of the rotor core 24) toward the outer peripheral surface of the rotor core 24. The third side edge 46c straddles the extending end of the first side edge 46a and the extending end of the second side edge 46b, and extends along the outer peripheral surface of the rotor core 24. A bridge portion 38 is provided between the third side edge 46c and the outer peripheral surface of the rotor core 24.
The inner peripheral side magnetic gap 35b and the outer peripheral side magnetic gap 35c function as a flux barrier that suppresses magnetic flux leakage from both ends of the permanent magnet M in the longitudinal direction to the rotor core 24, and also reduces the weight of the rotor core 24. Contribute.

The permanent magnet M is formed in a rectangular elongated flat plate shape, for example, and has a length substantially equal to the axial length of the rotor core 24. The permanent magnet M may be configured by combining magnets divided into a plurality of magnets in the axial direction (longitudinal direction). In this case, the total length of the plurality of magnets is substantially equal to the axial length of the rotor core 24. Is formed to be. The permanent magnet M is inserted into the magnet embedding hole 34A and is embedded over almost the entire length of the rotor core 24.
Further, in the cross section of the permanent magnet M, a permanent magnet divided into a plurality of pieces in the longitudinal direction or a permanent magnet divided into a plurality of pieces in the width direction may be combined to form a permanent magnet having a rectangular cross section. Good.

The permanent magnet M has a rectangular (for example, rectangular) cross-sectional shape, and has a first long side 37a and a second long side 37b that face each other in parallel, and a pair of short sides (first short side) that face each other. And the second short side). The first long side 37a has an inner end (inner angle) m1 located on the d-axis side (an angle at which the first long side and one short side intersect) m1 and an outer end located on the outer peripheral surface side of the rotor core 24. It has an end (outer angle) (angle at which the first long side and the other short side intersect) m2. The second long side 37b is the inner end (inner angle) m4 located on the d-axis side (the angle at which the second long side and one short side intersect) m4, and the outer side located on the outer peripheral surface side of the rotor core 24. It has an end (outer angle) (angle at which the second long side and the other short side intersect) m3.

The permanent magnet M is loaded into the magnet loading region 35a of the embedding hole 34A, the first long side 37a faces or abuts the first side edge 36a, and the second long side 37b faces or abuts the second side edge 36b. ing. In the permanent magnet M, a pair of corner portions are in contact with holding projections (not shown) in the magnet loading region 35a, respectively. As a result, the permanent magnet M is positioned within the magnet loading region 35a. As described above, the permanent magnet M may be fixed to the rotor core 24 with an adhesive or the like. The two permanent magnets M located on both sides of each d-axis in the circumferential direction are arranged so that the distance from the d-axis gradually increases from the inner end to the outer end.
The permanent magnet M is magnetized in a direction intersecting the first long side 37a and the second long side 37b, for example, in a direction orthogonal to each other. The two permanent magnets M located on both sides of the d-axis in the circumferential direction are arranged so that the magnetization directions are the same. Further, the two permanent magnets M located on both sides of the q-axis in the circumferential direction are arranged so that the magnetization directions are opposite to each other.

Next, a method of setting a suitable shape and arrangement of the magnet embedding holes (void layer or flux barrier) in the rotor 14 of the rotary electric machine 10 configured as described above will be described.
FIG. 3 is a diagram schematically showing a flux line used in a method of setting the shape and arrangement of magnet embedding holes (void layers) of a rotary electric machine according to an embodiment. In FIG. 3, R: the radius of the circumscribed circle centered on the central axis C circumscribing the outer circumference of the rotor core 24, r: the radius of the polar coordinate system sandwiched between the d-axis and the q-axis centered on the central axis C. Coordinates, θ: d-axis with center axis C as the center point, angular coordinates of the polar coordinate system sandwiched between q-axis, p: number of pole pairs (number of magnetic poles / 2), θd, θq: any point on the circumscribed circle The angular coordinates (θd: angular coordinates of the d-axis flux line, θq: angular coordinates of the q-axis flux line). The angular coordinates θd and θq are positive in the direction toward the d-axis with respect to the q-axis. The d-axis flux line fd (θd) passing through the point of the angular coordinate θd on the circumscribed circle is defined by the cylindrical coordinate system hyperbolic function as shown in the following equation (1).

ｄ軸フラックスラインとｑ軸フラックスラインとの交点の座標（ｒｄｑ、θｄｑ）は、下記の式（３）を満たすように設定する。

Similarly, the q-axis flux line fq (θq) passing through the point of the angular coordinate θq on the circumscribed circle is defined by the cylindrical coordinate system hyperbolic function as in the following equation (2).

The coordinates (rdq, θdq) of the intersection of the d-axis flux line and the q-axis flux line are set so as to satisfy the following equation (3).

When the void layer (embedded hole) is one layer as in the present embodiment, first, three arbitrary points (angle coordinates θ _q1 and θ _{q2) are placed on the outer circumference (circumscribed circle) of the rotor core 24 per magnetic pole.} , Θ _q3 ), and the first q-axis flux line fq (θ _q1 ), the second q-axis flux line fq (θ _q2 ), and the third _q- axis flux line f q (θ q3), which pass through the points at the respective angular coordinates, are expressed. Obtained from (2). It is assumed that the positions are located on the d-axis side in the order of _{θ q3} , θ _q2 , and θ _{q1 (θ q3} > θ _q2 > θ _q1 ), and θ _q1 and θ _q2 satisfy the following equation (4). Shall be.

_{Similarly, two arbitrary points (angle coordinates θ d1} and θ _d2 ) are given on the circumscribed circle of the rotor core 24, and the first d-axis flux line fd (θ _d1 ) and the second d-axis flux line passing through the respective points are given. Fd (θ _d2 ) is obtained from Eq. (1). Here, coordinate theta _d2, rather than the coordinate theta _d1 and coordinates located on the d-axis side (θ _d2> θ _d1), coordinates theta _d1 is the coordinate located on the d-axis side from the coordinate theta _q3 (theta _d1 > θ _q3 ).
The magnet loading region 35a of the embedding hole (void layer) 34A is provided in a region surrounded by the second _{q- axis flux line fd (θ q2} ) and the third q-axis flux line fd (θ q3).
In the permanent magnet M, the inner end (inner angle) m1 and the outer end (outer angle) m2 of the first long side 37a are located on the third _q- axis flux line f (θ q3), and the inner angle m1 is the third q-axis. It is assumed that the flux line f (θ _q3 ) is arranged and formed so as to be located at the intersection of the first d-axis flux line f (θ _d1).

_{Points b1 and b2 are set on the 2nd q-} axis flux line fq (θ _q2 ) and the 3rd q-axis flux line fq (θ q3), respectively, and the second bridge portion V2 on the outer peripheral side connects these two points with a straight line or an arc. Is formed. That is, the outer peripheral side magnetic gap 35c is formed and arranged so that the third side edge 46c extends between the points b1 and b2. Further, the first side edge 46a of the outer peripheral side magnetic gap 35c extends from the point b1 to the outer end (outer angle) m2 of the first long side 37a of the permanent magnet M along the _{third q-axis flux line fq (θ q3).} ing. The second side edge 46b of the outer peripheral side magnetic gap 35c extends from the point b2 to the outer end (outer angle) m3 of the second long side 37b of the permanent magnet M along the second _{q-axis flux line fq (θ q2).} It shall be.

The inner peripheral side magnetic gap 35b has a shape that extends from the corner portion of the permanent magnet M toward the q-axis side.
That is, at least a part of the second side edge 44b of the inner peripheral side magnetic gap 35b includes the intersection m5 of _{the second d-axis flux line fd (θ d2} ) and the first q-axis flux line f (θ _q1). It is located on the flux line f (θ _q1 ), and the other region of the second side edge 44b is located on the second q-axis flux line (θ q2) side of the _{first q-axis flux line f (θ q1).} Set. In the present embodiment, the second side edge 44b extends from the inner end (inner angle) m4 of the second long side 37b of the permanent magnet M to the intersection m5, and further extends from the intersection m5 to the vicinity of the d-axis. The first side edge 44a of the inner peripheral side magnetic gap 35b _{extends substantially along the third q-} axis flux line fq (θ q3) from the inner end (inner angle) m1 of the first long side 37a to the vicinity of the d-axis. ..

Here, FIG. 2 shows a configuration example in which the shape of the void layer (embedded hole 34A) of the rotor 14 is determined according to the above conditions. The points m1, m2, m3, m4, m5, b1 and b2 in FIG. 2 correspond to the points shown in FIG. 3, respectively. In one example, the second side edge 44b of the inner peripheral side magnetic gap 35b intersects the inner end (inner angle) m4 (the second long side 37b and the short side on the d-axis side) of the second long side 37b of the permanent magnet M. It extends from the corner) to the intersection m5, and extends from the intersection m5 to one end of the third side edge 44c.
The second side edge 44b is not limited to a configuration that extends linearly, and may be a configuration that extends curvedly.

上記の条件に従って内周側磁気空隙３５ｂの形状、配置を設定することにより、回転電機の発生トルクを０．９９７〜１（最大トルク）とすることが可能となる。 FIG. 4 shows a case where the arrangement of the permanent magnet M and the arrangement of the second bridge portion V2 are fixed, and the coordinates θ _q3 , θ _q2 , θ _q1 and θ _d1 in FIG. 3 are fixed and the coordinates θ _d2 are changed. The result of evaluating the influence on the torque generated by the rotating electric machine due to the difference in the shape of the inner peripheral side magnetic gap 35b by using the electromagnetic field analysis is shown. The horizontal axis represents a numerical value obtained by multiplying the coordinate displacement amount Δθ by the pole logarithm p. The vertical axis shows the value of the generated torque with the maximum generated torque as 1. As can be seen from FIG. 4, the generated torque _{becomes maximum near the position (Δθ × P = 0) where the coordinates θ d2} and the coordinates θ _d1 overlap, and the generated torque decreases as the distance from this position increases. (Δθ × P) is in the range of -3 to 9 (torque decrease is in the range of 0.3% or less), preferably in the range of -2 to 6 (torque decrease is in the range of 0.2% or less). It turns out that it can be obtained.
From the above, when the intersection m5 that determines the shape of the inner peripheral side magnetic gap 35b is located at the intersection of the second d-axis flux line fd (θ _d2 ) and the first q-axis flux line fd (θ _{q1), each hyperbola The angular coordinates θ d2} of the points on the circumscribed circle that determine the above are set so as to satisfy the following conditional expression (5).

By setting the shape and arrangement of the inner peripheral side magnetic gap 35b according to the above conditions, the torque generated by the rotary electric machine can be set to 0.997 to 1 (maximum torque).

The permanent magnet type rotary electric machine 10 configured as described above has a magnet torque generated by the action of the magnetic flux of the permanent magnet M and the armature current, and a relaxation torque generated by the magnetic salient pole seen from the armature winding 18. Occurs at the same time. According to the present embodiment, a gap layer including a magnet embedding hole and a permanent magnet is provided for each magnetic pole of the rotor core, and the arrangement and shape of the gap portion of the magnet embedding hole are set so as to satisfy the above-mentioned geometric condition formula. By doing so, a rotor that realizes a high torque without increasing the amount of magnets and a permanent magnet type rotating electric machine can be obtained.

Next, the rotor of the rotary electric machine according to the modified example will be described. In the modification described below, the same parts as those in the above-described embodiment are designated by the same reference numerals, and the detailed description thereof will be omitted or simplified, and the parts different from the embodiments will be mainly described.
(Modification example)
At each magnetic pole of the rotor, the void layer (magnet embedding hole) and the permanent magnet are formed and arranged symmetrically with respect to the d-axis, but the present invention is not limited to this and can be installed asymmetrically. Is.
FIG. 5 is a cross-sectional view showing one magnetic pole portion of the rotary electric machine according to the modified example. According to the modified example, the void layer (magnet embedding hole 34A) and the permanent magnet M are formed and arranged asymmetrically with respect to the d-axis.

As shown in FIG. 5, the magnet embedding hole (void layer) 34A and the permanent magnet M provided on one side of the d-axis are formed in the same shape and arrangement as the magnet embedding hole and the permanent magnet in the above-described embodiment. There is. In the magnet embedding hole (void layer) 34A and the permanent magnet M provided on the opposite side of the d-axis, the magnet loading area 35a, the outer peripheral side magnetic void 35c, and the permanent magnet M are the magnet embedding hole 34A and the permanent magnet on one side. It is formed in a shape and arrangement line-symmetrical with respect to the M and d axes. The inner peripheral side magnetic gap 35b is formed in a shape and arrangement asymmetrical with the inner peripheral side magnetic gap 35b on one side with respect to the d-axis.

The first side edge 44a and the third side edge 44c of the inner peripheral side magnetic gap 35b have a shape and arrangement line-symmetrical with the inner peripheral side magnetic gap 36b on one side, and the second side edge 44b of the inner peripheral side magnetic gap 35b. Only has an asymmetrical shape and arrangement. That is, the positions of the intersections m5 are different. _{The coordinate θ d2} shown in FIG. 3 is set at a position substantially overlapping the coordinate θ _d1, and the second d-axis flux line fd (θ _d2 ) and the first q-axis flux line fd (θ _q1 ) passing through the point of the coordinate θ d2 The intersection is m5. The second side edge 44b of the inner peripheral side magnetic gap 35b extends from the inner angle m4 of the permanent magnet M to the intersection m5, and further extends from the intersection m5 to the lower end (the end on the central axis C side) of the third side edge 44c. ..

Even in the modified example configured as described above, by setting the arrangement and shape of the gap portion of the magnet embedding hole 34A so as to satisfy the above-mentioned geometric condition formula, a high torque can be obtained without increasing the magnet amount. A rotor to be realized and a permanent magnet type rotary electric machine can be obtained.

It should be noted that the present invention is not limited to the above-described embodiments and modifications as they are, and at the implementation stage, the components can be modified and embodied within a range that does not deviate 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, etc. of the rotor are not limited to the above-described embodiment, and can be variously changed according to the design. The cross-sectional shape of the permanent magnet is not limited to a rectangular parallelepiped, and may be another shape, for example, a trapezoid. As the permanent magnet, a magnet obtained by laminating a plurality of permanent magnets to form a desired shape may be used. Further, the void layer of the rotor core is not limited to one layer, and a plurality of layers, for example, two layers or three layers may be provided on one side of the d-axis. In this case, the void layer of the second layer and / or the third layer may be a void layer containing a permanent magnet or a void layer not containing a permanent magnet.

10 ... Rotor, 12 ... Stator, 14 ... Rotor, 16 ... Stator iron core,
18 ... armature winding, 20 ... slot, 22 ... shaft, 24 ... rotor core,
34A ... Magnet embedding hole (void layer), 35a ... Magnet loading area, 35b ... Inner peripheral side magnetic gap,
37a ... 1st long side, 37b ... 2nd long side, 44a, 46a ... 1st inner edge,
44b, 46b ... 2nd inner edge, 44c, 46c ... 3rd inner edge, 35c ... outer peripheral magnetic void,
M ... Permanent magnet, V1, V2 ... Bridge

Claims (3)

A plurality of magnetic poles provided side by side in the circumferential direction around the central axis, an end of the magnetic pole in the circumferential direction, and an axis extending in the radial direction through the central axis are defined as the q-axis, with respect to the q-axis. When the axis electrically separated by 90 degrees in the circumferential direction is defined as the d-axis, the magnetic gap on the inner peripheral side facing the d-axis via the first bridge portion and the outer peripheral surface via the second bridge portion A rotor core including a gap layer including a magnetic gap on the outer peripheral side facing each other, a magnetic gap on the inner peripheral side, and a magnet loading region located between the magnetic gap on the inner peripheral side and the magnetic gap on the outer peripheral side.
The first long side having an inner end m1 on the d-axis side and an outer end m2 on the outer peripheral surface side, an inner end m4 on the d-axis side, and an outer end m3 on the outer peripheral surface side. A permanent magnet formed in a rectangular cross-sectional shape having a second long side facing the first long side at a distance from the first long side located on the q-axis side with respect to the side and arranged in the magnet loading region. With
In the cross section of the rotor core orthogonal to the central axis,
R: The radius of the circumscribed circle centered on the central axis that circumscribes the outer circumference of the rotor core.
r: Radial coordinates of the polar coordinate system sandwiched between the d-axis and the q-axis with the central axis as the center point.
θ: The d-axis with the central axis as the center point, the angular coordinates of the polar coordinate system sandwiched between the q-axis (the direction toward the d-axis is positive with respect to the q-axis),
p: Number of pole pairs (number of magnetic poles / 2),
θd: Angular coordinates of any point on the circumscribed circle,
θq: Angular coordinates of any point on the circumscribed circle,
As a d-axis flux line passing through the coordinates (R, θd) is defined by the following equation (1).

The q-axis flux line passing through the coordinates (R, θq) is defined by the following equation (2).

The coordinates (rdq, θdq) of the intersection of the d-axis flux line and the q-axis flux line are defined by the following equation (3).

The angular coordinates of any three points set on the circumscribed circle are θ _q1 , θ _q2 , θ _q3 (θ _q3 > θ _q2 > θ _q1 ), and the angular coordinates of any two points set on the circumscribed circle. Let θ _d1 and θ _d2 (θ _d2 > θ _d1 > θ _q3 ).
The q-axis flux lines passing through the respective points of the angular coordinates θ _q1 , θ _q2 , and θ _{q3 are the q-axis flux line fd (θ q1} ), the q-axis flux line fd (θ _q2 ), and the q-axis flux line fd (θ _q3). )age,
_{Assuming that} the d-axis flux lines passing through the points of the angular coordinates θ _d1 and θ _{d2 are the d-axis flux line fd (θ d1} ) and the d-axis flux line fd (θ _d2 ), respectively.
The magnet loading region is provided in a region surrounded by the q-axis flux line fd (θ _q2 ) and the q-axis flux line fd (θ _q3).
The permanent magnet, the inner end m1 and an outer end m2 of the first long side is positioned on the q-axis flux lines fd (theta _q3), the inner end m1 is the q-axis flux lines fd and (theta _q3) It is arranged so as to be located at the intersection with the d-axis flux line fd (θ _d1).
The inner peripheral side magnetic gap extends from the inner end m4 of the second long side of the permanent magnet to the intersection m5 of the _{q-axis flux line fd (θ q1} ) and the d-axis flux line fd (θ _d2). It has a side edge extending from the intersection m5 to the d-axis side.
_{The angular coordinate θ d2} that defines the intersection m5 is the following conditional expression (3).

Rotor that meets. The angular coordinates θ _q1 and θ _q2 are the following conditional expressions (4).

The rotor according to claim 1. The rotor according to claim 1, wherein the void layers provided on both sides of the d-axis in the circumferential direction are formed and arranged line-symmetrically or non-symmetrically with respect to the d-axis.

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