JP7401381B2 - permanent magnet electric motor - Google Patents

Description

The present invention relates to a permanent magnet electric motor in which permanent magnets are inserted into magnet insertion holes formed in a rotor.

Permanent magnet motors are used as drive devices for compressors, air conditioners, on-vehicle equipment, etc. As the permanent magnet, an inexpensive ferrite magnet or a rare earth magnet that is more expensive than a ferrite magnet but has a large residual magnetic flux density and coercive force, such as a neodymium magnet containing neodymium (Nd) and iron (Fe), is used.
As permanent magnet motors, for example, permanent magnet motors disclosed in Patent Document 1 and Non-Patent Document 1 are known. The permanent magnet motor disclosed in Patent Document 1 and Non-Patent Document 1 includes a stator and a rotor. The rotor has a main magnetic pole and an auxiliary magnetic pole, a magnet insertion hole is formed in the main magnetic pole, and a permanent magnet is inserted in the magnet insertion hole. The torque T of such a permanent magnet motor is determined by the amount of magnetic flux due to the permanent magnet Φ, the q-axis current Iq, the d-axis current Id, the q-axis inductance Lq, the d-axis inductance Ld, and the number of pole pairs of the rotor P Then, it is expressed by the following formula.
T=P[Φ×Iq+(Ld-Lq)×Id×Iq]
The first term on the right side of the above equation indicates the magnetic torque due to the magnetic flux of the permanent magnet, and the second term indicates the reluctance torque due to the saliency of the rotor (the difference between the d-axis inductance Ld and the q-axis inductance Lq). There is.
Here, by setting (Lq>Ld) and controlling the advance angle of the current in the stator winding (by passing a negative d-axis current Id), the reluctance torque becomes positive, and the sum of the magnet torque and the reluctance torque , the torque T increases.
Therefore, in conventional permanent magnet motors, in order to increase the torque T of the permanent magnet motor by effectively utilizing reluctance torque, the q-axis inductance Lq is configured to be sufficiently larger than the d-axis inductance Ld. . Note that by effectively utilizing reluctance torque, the number of turns of the stator winding wound around the teeth of the stator can be reduced. As a result, the resistance value of the stator winding is reduced and copper loss is reduced.
The magnetic flux generated by the permanent magnet and the magnetic flux generated by current flowing through the stator windings flow through the teeth of the stator. The magnetic flux generated by current flowing through the stator windings increases as the current increases. That is, the magnetic flux flowing through the teeth increases as the current flowing through the stator windings increases. Therefore, when the current flowing through the stator winding increases, the magnetic flux density of the teeth becomes saturated, and the q-axis inductance Lq decreases.
In order to generate high efficiency and high torque in such a permanent magnet motor, the q-axis inductance Lq is set to be larger than the d-axis inductance Ld in a region where the current is large. Therefore, in the conventional permanent magnet electric motor, the d-axis inductance Ld and the q-axis inductance Lq are configured to have the current characteristics shown in FIG. 3. That is, the d-axis inductance Ld remains approximately the same even if the current increases or decreases. On the other hand, the q-axis inductance Lq is large when the current is small, and decreases as the current increases due to saturation of the magnetic flux density of the teeth.

Japanese Patent Application Publication No. 2002-136011

Proceedings of the Institute of Electrical Engineers of Japan, Vol. 113-D, No. 11, pp. 1330-1331, 1993

In conventional permanent magnet electric motors, thick permanent magnets are used to prevent demagnetization of the permanent magnets. Therefore, as shown in FIG. 3, the d-axis inductance Ld has a current characteristic that remains almost the same even if the current increases or decreases.
In this way, if the d-axis inductance Ld has a current characteristic that is almost the same even when the current increases or decreases, the difference between the q-axis inductance Lq and the d-axis inductance Ld will be increased in the region where the current is large. I can't . The reluctance torque of the permanent magnet motor is determined by the difference between the q-axis inductance Lq and the d-axis inductance Ld, as shown by the above-mentioned formula. For this reason, in conventional permanent magnet motors, it has been impossible to increase reluctance torque in a region where the current is large. In this case, in order to increase the torque, it is necessary to flow a large current through the stator windings, which increases copper loss and reduces efficiency.
The present invention was devised in view of these points, and an object of the present invention is to provide a permanent magnet motor that can reduce the d-axis inductance Ld and increase the reluctance torque in a region where the current is large. .

The first invention relates to a permanent magnet electric motor including a stator and a rotor.
The stator includes a yoke that extends along the circumferential direction, and a tooth tip surface that extends radially inward from the yoke and extends radially inward along the circumferential direction. It has a plurality of teeth, a plurality of slots formed by circumferentially adjacent teeth, and a stator winding wound around each tooth in a concentrated winding method . The tooth tip surfaces form the stator inner peripheral surface.
The rotor is rotatably supported within the stator inner space formed by the stator inner peripheral surface. Further, in the rotor, main magnetic poles and auxiliary magnetic poles are alternately arranged along the circumferential direction, and a magnet insertion hole extending along the axial direction is formed in the main magnetic pole. A permanent magnet is inserted into the magnet insertion hole. Although various permanent magnets can be used as the permanent magnet, neodymium magnets are preferably used. More preferably, a neodymium magnet in which dysprosium (Dy) or terbium (Tb) is diffused is used. The permanent magnet inserted into the magnet insertion hole defines the main magnetic pole and the auxiliary magnetic pole, and also defines the d-axis of the main magnetic pole and the q-axis of the auxiliary magnetic pole. Note that the d-axis is defined as a line connecting the rotation center of the rotor and the circumferential center of the main magnetic pole, and the q-axis is defined as a line connecting the rotation center of the rotor and the circumferential center of the auxiliary magnetic pole.
In the present invention, six main magnetic poles and nine slots are provided. That is, it is configured as a concentrated winding permanent magnet motor with 6 poles and 9 slots.
The outer circumferential surface of the rotor includes a first outer circumferential surface portion that intersects with the d-axis of the main magnetic pole, a second outer circumferential surface portion that intersects with the q-axis of the auxiliary magnetic pole, and a first outer circumferential surface portion and a second outer circumferential surface portion. It has a connecting part that connects the surface parts. The first outer circumferential surface portion is formed into an arc shape with a radius R1 centered around the rotation center. The second outer circumferential surface portion is formed in an arc shape having a radius R2 smaller than the radius R1 (R2<R1) with the center of rotation as the center point.
The diameter D (mm) of the rotor is set to satisfy [58 mm≦D≦ 93 mm ]. Further, the distance G (mm) between the first outer circumferential surface portion and the stator inner circumferential surface is set to satisfy [0.5 mm≦G≦0.6 mm]. Further, the opening angle θ1 (mechanical angle) of the first outer peripheral surface portion with respect to the center of rotation is set to satisfy [16 degrees≦θ1≦19 degrees]. Further, the distance H (mm) along the radial direction between the first outer circumferential surface portion and the second outer circumferential surface portion is set such that it satisfies [2×G<H<2×G×1.1]. is set to . Further, the thickness W (mm) of the permanent magnet is set to satisfy [2×G×0.9<W<2×G×1.1]. Further, the width T of the teeth is set to satisfy [0.2×(D+ 2×G )×π/9<T<0.23×(D+2 ×G )×π/9].
In the present invention, the q-axis inductance Lq is reduced in a region where the current is large, as the q-axis magnetic flux flowing through the teeth is saturated, as in the conventional permanent magnet motor. On the other hand, the d-axis inductance Ld becomes smaller than that of the conventional permanent magnet motor because the d-axis magnetic flux flowing through the teeth is saturated in a region where the current is large. Thereby, the difference between the q-axis inductance Lq and the d-axis inductance Ld in the region where the current is large can be made larger than that of a conventional permanent magnet motor, and the reluctance torque in the region where the current is large can be increased.
In a different embodiment of the first invention, a permanent magnet having a saturation magnetic flux density within a range of 1.4 Tesla and 1.6 Tesla is used as the permanent magnet.
In a different form of the first invention, the stator and the rotor are made of electrical steel sheets whose magnetic flux density transitions from a linear region to a nonlinear region within a range of 1.75 Tesla and 1.9 Tesla.
A second invention relates to a compressor that includes a compression mechanism and an electric motor that drives the compression mechanism. As the electric motor, any of the above-mentioned permanent magnet electric motors is used.
The second invention has the same effects as the first invention.

In the permanent magnet motor and compressor of the present invention, the d-axis inductance can be reduced in the region where the current is large, and the reluctance torque can be increased in the region where the current is large.

1 is a cross-sectional view of a permanent magnet electric motor according to a first embodiment. FIG. 2 is an enlarged view of the main part of FIG. 1. FIG. It is a graph showing the current characteristics of the d-axis inductance Ld and the q-axis inductance Lq of a conventional permanent magnet motor. It is a graph showing the current characteristics of the d-axis inductance Ld and the q-axis inductance Lq of the permanent magnet motor of the first embodiment. FIG. 3 is a sectional view of a rotor of a permanent magnet motor according to a second embodiment. FIG. 7 is a sectional view of a rotor of a permanent magnet motor according to a third embodiment. It is a sectional view of the rotor of the permanent magnet electric motor of a 4th embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
Note that in this specification, the term "axial direction" refers to the direction in which the rotational center line passing through the rotational center of the rotor when the rotor is rotatably arranged relative to the stator. . The term "circumferential direction" refers to the circumferential direction around the rotation center of the rotor when viewed from the axial direction in a state where the rotor is rotatably arranged relative to the stator. The term "radial direction" refers to a direction passing through the center of rotation of the rotor when viewed from the axial direction when the rotor is rotatably arranged relative to the stator.

A first embodiment 100 of a permanent magnet motor of the present invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a sectional view of a permanent magnet motor 100 according to the first embodiment, and FIG. 2 is an enlarged view of the main parts of FIG. 1.
Permanent magnet electric motor 100 includes a stator 110 and a rotor 120.
The stator 110 is constituted by a stator core formed by laminating a plurality of plate-shaped electromagnetic steel plates. The stator 110 has a yoke 111 extending along the circumferential direction and teeth 112 extending radially inward from the yoke 111. The teeth 112 are formed by a tooth base 113 that extends radially inward from the yoke along the radial direction, and a tooth tip 114 that is connected to the radially inner side of the tooth base 113 and extends along the circumferential direction. ing. A tooth tip surface 115 is formed inside the tooth tip portion 114 in the radial direction. The tooth tip surface 115 is formed in an arc shape with the rotation center O as the center point. A stator inner space is formed inside the stator 110 by the tooth tip surface 115 of each tooth 112 . The tooth tip surface 115 corresponds to the "stator inner peripheral surface" of the present invention.
A slot 116 is formed by teeth 112 adjacent in the circumferential direction.
In the permanent magnet motor 100 of this embodiment, nine teeth 112 (slots 116) are provided ( 9-slot permanent magnet motor). The stator winding (not shown) is wound around each tooth 112 (more specifically, around the tooth base 113) using a concentrated winding method .
Various methods can be used to wind the stator winding in a concentrated winding manner .

The rotor 120 is constituted by a rotor core formed by laminating a plurality of plate-shaped electromagnetic steel plates. The rotor 120 has a rotating shaft (not shown) inserted into a rotating shaft insertion hole formed by the inner peripheral surface 210, and is rotatably disposed within the stator inner space of the stator 110. In the present embodiment, the rotor 120 is arranged such that an air gap is maintained between the first outer circumferential surface portion 120a (described later) and the tooth tip surface 115 (stator inner circumferential surface). ing.
The rotor 120 has main magnetic poles [A] to [F] and auxiliary magnetic poles [AB] to [FA] arranged alternately along the circumferential direction. In this embodiment, the number of main magnetic poles (number of poles) of the rotor 120 is set to six . That is, it has a rotor 120 with a six-pole structure ( six-pole permanent magnet motor). Note that a rotor with six poles is called a rotor with three pole pairs P.
A first magnet insertion hole 131 and a second magnet insertion hole 132 are formed in each main magnetic pole, and a first permanent magnet 141 and a second permanent magnet are formed in the first magnet insertion hole 131 and second magnet insertion hole 132. A permanent magnet 142 is inserted. Although various permanent magnets can be used as the first permanent magnet 141 and the second permanent magnet 142, neodymium magnets are preferably used. More preferably, a neodymium magnet in which dysprosium (Dy) or terbium (Tb) is diffused is used.
The first permanent magnet 141 and the second permanent magnet 142 define the main magnetic poles [A] to [F] and the auxiliary magnetic poles [AB] to [FA] , and also the main magnetic poles [A] to [F]. The d-axis and the q-axis of the auxiliary magnetic poles [AB] to [FA] are defined.
The d-axis is defined as a line connecting the rotation center O and the circumferential centers of the main magnetic poles [A] to [F] , and the q-axis is defined as the line connecting the rotation center O and the circumferential centers of the auxiliary magnetic poles [AB] to [FA]. It is defined as a connecting line.

The rotor outer circumferential surface of the rotor 120 includes a first outer circumferential surface portion 120a that intersects with the d-axis, and a second outer circumferential surface that intersects with the q-axis and is formed radially inward from the first outer circumferential surface portion 120a. It has a portion 120b, and connecting portions 120c and 120d that connect the first outer circumferential surface portion 120a and the second outer circumferential surface portion 120b. The second outer circumferential surface portion 120b, the connecting portions 120c and 120d are the bottom surface of the cutout in the first outer circumferential surface portion 120a, the side surface on one side in the circumferential direction (clockwise direction), and the side surface on the other side in the circumferential direction (counterclockwise direction). It can also be called the side of the side.
In this embodiment, the first outer peripheral surface portion 120a has a circular arc shape with a radius R1 (R1=D/2) centered around the rotation center O, and the second outer peripheral surface portion 120b has a circular arc shape with the rotation center O as the center point. It has an arcuate shape with radius R2 smaller than radius R1 (R2<R1) with the center point at . Further, the connecting portions 120c and 120d linearly extend parallel (including "substantially parallel") to the d-axis. The connecting portions 120c and 120d may also be formed to extend linearly in parallel (including “substantially parallel”) to the radial direction passing through the rotation center O. Note that the shapes of the first outer circumferential surface portion 120a, the second outer circumferential surface portion 120b, and the connecting portions 120c and 120d are not limited to these.

In the present embodiment, the main magnetic poles [A] to [F] have a first magnet insertion hole 131 and a second magnet insertion hole 132 that extend linearly on both sides of the d-axis, and are located at the center of rotation. It is formed in a V-shape that protrudes toward the O side.
Between the inner circumference side end wall part 131c of the first magnet insertion hole 131 and the inner circumference side end wall part 132c of the second magnet insertion hole 132, there is a space extending parallel to (including "substantially parallel to") the d-axis. A central bridge portion 125 is formed. Further, an outer bridge portion 126 is formed between the outer circumferential end wall portion 131d of the first magnet insertion hole 131 and the second outer circumferential surface portion 120b, and the outer circumferential end wall portion of the second magnet insertion hole 132 is formed with an outer circumferential bridge portion 126. An outer peripheral bridge portion 127 is formed between 132d and the second outer peripheral surface portion 120b.
A first permanent magnet 141 and a second permanent magnet 142 extending linearly are inserted into the first magnet insertion hole 131 and the second magnet insertion hole 132 . A gap is provided at both ends of the first permanent magnet 141 and the second permanent magnet 142.

Next, in this embodiment, a configuration for reducing the d-axis inductance Ld in a region where the current is large will be described.
In addition, in this embodiment, the diameter D of the rotor 120 is set within the range of [58 mm≦D≦93 mm]. Further, as described above, the number of slots 116 of the stator 110 is set to 9 (9 slots), and the number of main magnetic poles of the rotor 120 is set to 6 (6 poles or the number of pole pairs P is 3). .

As the magnetic flux flowing through the rotor 120 as shown in FIG. 2, d-axis magnetic flux and q-axis magnetic flux can be considered.
The d-axis magnetic flux is the magnetic flux flowing between adjacent main magnetic poles. For example, the flow flows into the rotor 120 from the d-axis side of the main magnetic pole [A] , and the d-axis side of the main magnetic pole [B] that is adjacent to the main magnetic pole [A] on one side in the circumferential direction (clockwise in FIG. 2) This is the magnetic flux flowing out from the The d-axis inductance Ld is determined by the d-axis magnetic flux.
The q-axis magnetic flux is a magnetic flux flowing between adjacent auxiliary magnetic poles. For example , the rotor is 120 and flows out from the auxiliary magnetic pole [ AB ] side between the main magnetic pole [A] and the main magnetic pole [B] adjacent to the main magnetic pole [ A ] on one side in the circumferential direction. The q-axis inductance Lq is determined by the q-axis magnetic flux.

Next, a configuration for reducing the d-axis inductance Ld in a region where the current is large will be described below.
In a conventional permanent magnet electric motor, the d-axis magnetic flux flowing through the teeth is set so as not to be saturated, so the d-axis inductance Ld has a current characteristic that does not change substantially even if the current increases or decreases.
In contrast, in this embodiment, the d-axis magnetic flux flowing through the teeth is set to saturate, so that the current characteristic is such that the d-axis inductance Ld becomes small in a region where the current is large. .
Specifically, we specialized in 6-pole, 9-slot concentrated winding permanent magnet motors.

The gap G is set within the range of 0.5 mm and 0.6 mm (satisfying [0.5 mm≦G≦0.6 mm]).
If the air gap G is smaller than 0.5 mm, high frequency iron loss will increase, efficiency will decrease, and noise and vibration will also increase.
If the air gap G is larger than 0.6 mm, the amount of magnetic flux will decrease and iron loss will increase.

The diameter D of the rotor 120 is set within the range of 58 mm and 93 mm (satisfying [58 mm≦D≦93 mm]).
If the diameter D is smaller than 58 mm, a sufficient magnet surface area cannot be secured because of the notch formed by the second outer peripheral surface portion 120b. Therefore, the amount of magnetic flux decreases, iron loss increases, and efficiency decreases.

The opening angle θ1 of the first outer circumferential surface portion 120a with respect to the rotation center O is set within the range of 16 degrees and 19 degrees (mechanical angle) (satisfying [16 degrees≦θ1≦19 degrees]).
When the opening angle θ1 is smaller than 16 degrees, sufficient magnetic flux cannot be secured, copper loss increases, and efficiency decreases.
When the opening angle θ1 is larger than 19 degrees, high frequency iron loss increases and efficiency decreases.

The distance (depth of the notch) Hmm in the radial direction between the first outer circumferential surface portion 120a and the second outer circumferential surface portion 120b is [2×G<H<2×G×1.1 ] is set to satisfy.

The thickness Wmm of the permanent magnets 141 and 142 is set to satisfy [2×G×0.9<W<2×G×1.1].

The width of the teeth 112 (specifically, the minimum width of the tooth base 113) Tmm is determined by [0.2×(stator inner circumference/9)<T<0.23×(stator inner circumference/9)]. set to your satisfaction. Note that the stator inner circumference (mm) is expressed as [stator inner circumference=(diameter D of rotor 120+ 2×gap G) ×π].
If the width T of the teeth 112 is smaller than [0.2×(stator inner circumference/9)], sufficient magnetic flux will not flow from the teeth 112 to the rotor 120. This increases copper loss and reduces efficiency.
When the width T of the teeth 112 is larger than [0.23×(stator inner circumference/9)], sufficient magnetic flux flows between the teeth 112 and the rotor 120, and the d-axis magnetic flux is not saturated. In this case, the d-axis inductance Ld exhibits the same current characteristics as a conventional permanent magnet motor.

Note that as the permanent magnets 141 and 142, permanent magnets whose saturation magnetic flux density is within the range of 1.4 Tesla and 1.6 Tesla are preferably used.
Preferably, the magnetic steel sheets constituting the stator 110 (stator core) and the rotor 120 (rotor core) have a magnetic flux density within the range of 1.75 Tesla and 1.9 Tesla from the linear region. An electrical steel sheet that transitions to a nonlinear region is used.

The permanent magnet electric motor 100 of the first embodiment has a six-pole structure (number of pole pairs P= 3 ) when viewed in a cross section perpendicular to the axial direction, and each main magnetic pole [A] to [F] extends linearly. The first magnet insertion hole 131 and the second magnet insertion hole 132 are formed in a V-shape protruding toward the rotation center O side, and the first magnet insertion hole 131 and the second magnet insertion hole 132 are formed in a V-shape protruding toward the rotation center O side. , a rotor 120 in which a first permanent magnet 141 and a second permanent magnet 142 that extend linearly are inserted is used, but the arrangement shape of the magnet insertion hole of each main pole of the rotor, etc. can be changed in various ways. It is possible.

A rotor 220 of a second embodiment of a permanent magnet motor is shown in FIG.
The rotor 220 shown in FIG. 5 has a six-pole structure (number of pole pairs P= 3 ), and each main pole has a magnet insertion hole 231 extending linearly in a direction intersecting the d-axis (preferably is formed in a perpendicular direction). A linearly extending permanent magnet 241 is inserted into the magnet insertion hole 231.
The outer circumferential surface of the rotor 220 has a first outer circumferential surface portion 220a that intersects with the d-axis, a second outer circumferential surface portion 220b that intersects with the q-axis, and connection portions 220c and 220d.

A rotor 320 of a permanent magnet motor according to a third embodiment is shown in FIG.
The rotor 320 shown in FIG. 6 has a six-pole structure (number of pole pairs P = 3 ), and each main pole has a magnet insertion hole 331 extending in an arc shape, which intersects the d-axis and is located at the center of rotation . It is formed so as to protrude toward the O side . A permanent magnet 341 extending in an arc shape is inserted into the magnet insertion hole 331 .
The outer circumferential surface of the rotor 320 has a first outer circumferential surface portion 320a that intersects with the d-axis, a second outer circumferential surface portion 320b that intersects with the q-axis, and connection portions 320c and 320d.

A rotor 420 of a permanent magnet motor according to a fourth embodiment is shown in FIG.
The rotor 420 shown in FIG. 7 has a six-pole structure (number of pole pairs P= 3 ), and each main magnetic pole has first to third magnet insertion holes 431 to 433 extending linearly. It is formed into a trapezoidal shape that protrudes toward the center O side. First to third permanent magnets 441 to 443 extending linearly are inserted into the first to third magnet insertion holes 431 to 433, respectively.
The outer circumferential surface of the rotor 420 has a first outer circumferential surface portion 420a that intersects with the d-axis, a second outer circumferential surface portion 420b that intersects with the q-axis, and connection portions 420c and 420d.
Note that it is also possible to form a trapezoidal magnet insertion hole protruding toward the rotation center O side in each main pole, and insert first to third permanent magnets extending linearly into the magnet insertion hole. .

The present invention is not limited to the configuration described in the embodiments, and various changes, additions, and deletions are possible.
Although a permanent magnet motor has been described, the present invention can be configured as various products using a permanent magnet motor as a drive unit. For example, it can be configured as a compressor in which the compression mechanism is driven by a permanent magnet motor.
The shape, number, and arrangement position of the magnet insertion hole formed in each main magnetic pole of the rotor, and the shape, number, and insertion position of the permanent magnets inserted into the magnet insertion hole can be changed as appropriate.
Each configuration described in the embodiment can be used alone, or a plurality of appropriately selected configurations can be used in combination.

100 Permanent magnet electric motor 110 Stator 111 Yoke 112 Teeth 113 Teeth base 114 Teeth tip 115 Teeth tip surface (stator inner peripheral surface)
116 Slots 120, 220, 320, 420 Rotor 120a, 220a, 320a, 420a First outer peripheral surface portion 120b, 220b, 320b, 420b Second outer peripheral surface portion
120c, 120d, 220c, 220d, 320c, 320d, 420c, 420d connection portion 125 central bridge portion 126, 127 outer bridge portion 131, 132, 231, 331, 431, 432, 433 magnet insertion hole 141, 142, 241, 341 , 441, 442, 443 Permanent magnet 210 inner peripheral surface (rotor inner peripheral surface)

Claims (4)

The stator includes a stator and a rotor, and the stator includes a plurality of teeth spaced apart along the circumferential direction, a plurality of slots formed by circumferentially adjacent teeth, and a plurality of slots wound around each tooth. The rotor has a stator winding and a stator inner circumferential surface forming a stator inner space, and the rotor is rotatably disposed within the stator inner space, and a main magnetic pole and an auxiliary magnetic pole are arranged along the circumferential direction. A permanent magnet electric motor in which permanent magnets are arranged alternately, magnet insertion holes are formed in the main magnetic poles, and permanent magnets are inserted in the magnet insertion holes,
The stator winding is wound around the plurality of teeth in a concentrated winding manner,
The main magnetic poles are provided in six pieces,
Nine slots are provided,
The outer circumferential surface of the rotor intersects with the d-axis of the main magnetic pole, and a first outer circumferential surface portion formed in an arc shape with a radius R1 centered on the rotation center intersects with the q-axis of the auxiliary magnetic pole. and connects the first outer circumferential surface portion and the second outer circumferential surface portion with a second outer circumferential surface portion formed in an arc shape with a radius R2 (R2<R1) having the center of rotation as the center point. a connecting part;
The diameter D (mm) of the rotor is set to satisfy [58 mm≦D≦93 mm],
A distance G (mm) between the first outer circumferential surface portion and the stator inner circumferential surface is set to satisfy [0.5 mm≦G≦0.6 mm],
The opening angle θ1 (mechanical angle) of the first outer peripheral surface portion with respect to the rotation center is set to satisfy [16 degrees≦θ1≦19 degrees],
The distance H (mm) along the radial direction between the first outer circumferential surface portion and the second outer circumferential surface portion satisfies [2×G<H<2×G×1.1]. is set to
The thickness W (mm) of the permanent magnet is set to satisfy [2×G×0.9<W<2×G×1.1],
The width T of the teeth is set to satisfy [0.20×(D+2×G)×π/9<T<0.23×(D+2×G)×π/9]. Permanent magnet electric motor. The permanent magnet electric motor according to claim 1,
A permanent magnet electric motor, wherein a permanent magnet having a saturation magnetic flux density within a range of 1.4 Tesla and 1.6 Tesla is used as the permanent magnet. The permanent magnet electric motor according to claim 1 or 2,
A permanent magnet electric motor, wherein the stator and the rotor are made of electromagnetic steel plates whose magnetic flux density transitions from a linear region to a nonlinear region within a range of 1.75 Tesla and 1.9 Tesla. A compressor comprising a compression mechanism section and an electric motor for driving the compression mechanism section, the permanent magnet electric motor according to any one of claims 1 to 3 being used as the electric motor. compressor.

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