JP2001095182A - Permanent magent electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cut cost by using magnet torque and reluctance torque together and by raising the reluctance torque in a permanent magnet electric motor. SOLUTION: On a rotor 10 inside a stator 1 that generates revolving magnetic field of a permanent magnet electric motor, permanent magnets 11a, 11b of a rectangular shape in cross section are arranged as a pair in an inverted V- shape of an obtuse angle, the point of which is directed to a shaft 4, and embedded at an equal interval in the circumferential direction by the number of poles of the permanent magnet electric motor. The polarity of the d-axis side of each pair of the permanent magnets 11a, 11b is made the same and the neighboring pairs of permanent magnets 11a, 11b are magnetized to the different polarity. Flux barrier holes 12 that are common to the end part of the outside circumference sides of the core corresponding to the permanent magnet 11a, 11b are formed around q-axis, and the outside circumference of the core around the d-axis is cut out in an inverted arcuate shape to form cutout parts 13 of a grooved shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet motor for a motor used in an air conditioner or an electric vehicle, and more particularly to a permanent magnet motor using both a magnet torque and a reluctance torque.

[0002]

2. Description of the Related Art This permanent magnet motor has, for example, the structure shown in FIG. 9, and has a rotor 2 inside a 24-slot stator 1 for generating a rotating magnetic field. The rotor 2 positions a pair of permanent magnets 3 a and 3 b having a rectangular cross section in an inverted V-shape with an obtuse angle and directs the apex side of the obtuse angle toward the shaft 4 by the number of poles (4 poles) of the permanent magnet motor. Only at equal intervals in the circumferential direction.

A pair of permanent magnets 3a, 3b are magnetized at right angles to the long sides of the pair of permanent magnets 3a, 3b so that the side surfaces (d-axis side) of the rectangular cross section are magnetic poles. 3
b is a different polarity. And these permanent magnets 3a, 3b
By using the rotor 2 in which is embedded, a magnet torque as a rotational force is generated.

Further, since the pair of permanent magnets 3a and 3b are arranged in an obtuse V-shape, the path of the magnetic flux from one q-axis to the other q-axis of the magnetic flux from the stator 1 (magnetic flux). Road)
(See the dashed arrow in FIG. 9), and the permanent magnets 3a and 3b are interposed in the magnetic flux path from one d-axis to the other d-axis. Therefore, the difference between the d-axis and q-axis inductances is increased, and reluctance torque can be generated.
Further, since the torque obtained by adding the reluctance torque and the magnet torque becomes the maximum torque of the permanent magnet electric motor, high efficiency and high torque of the motor can be achieved.

[0005]

In the above-described permanent magnet electric motor, the permanent magnets 3a and 3b are rod-shaped with a rectangular cross section. But cheaper.
Further, if the permanent magnets 3a and 3b are made thicker by increasing the thickness of the rectangular cross section to increase the magnet usage, the magnet torque can be increased. Therefore, the maximum torque (total torque) of the permanent magnet motor is increased. Can be. However, in this case, there is a drawback that the cost of the permanent magnet motor increases due to the increase in the magnet usage of the pair of permanent magnets 3a and 3b.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to increase the reluctance torque at low cost without increasing the amount of permanent magnets, while using both magnet torque and reluctance torque. An object of the present invention is to provide a permanent magnet electric motor capable of achieving high torque and high efficiency.

[0007]

In order to achieve the above object, the present invention relates to a permanent magnet motor having a rotor inside a stator for generating a rotating magnetic field, wherein the rotor comprises:
A pair of permanent magnets having a rectangular cross section are positioned in a V-shape at an obtuse angle with the apex of the obtuse angle facing the shaft, and the pair of permanent magnets are equally spaced in the circumferential direction by the number of poles of the permanent magnet motor. Embedded, d for each pair of permanent magnets
A pair of adjacent permanent magnets are magnetized to different polarities on the side surfaces of the shaft, and a pair of adjacent permanent magnets are magnetized to different polarities. The outer periphery of the core is cut out in the vicinity to form a groove-shaped cutout, so that a magnet torque and a reluctance torque are generated.

According to the present invention, there is provided a permanent magnet motor having a rotor inside a stator for generating a rotating magnetic field, wherein the rotor includes a pair of permanent magnets having a rectangular cross section and is positioned in an obtuse V-shape. The apex of the obtuse angle is directed toward the shaft, the pair of permanent magnets are embedded at equal intervals in the circumferential direction by the number of poles of the permanent magnet motor, the d-axis side surfaces of each pair of permanent magnets have the same polarity, and While a pair of adjacent permanent magnets are magnetized to different poles, the space between the pair of adjacent permanent magnets is widened to form a supplementary pole near the q-axis, and the outer periphery of the core is cut off near the d-axis to form a groove. Forming a cutout of the shape,
It is characterized in that a magnet torque and a reluctance torque are generated.

According to the present invention, there is provided a permanent magnet motor having a rotor inside a stator for generating a rotating magnetic field, wherein the rotor includes a pair of permanent magnets having a rectangular cross section and is positioned in an obtuse V-shape. Pointing the apex of the obtuse angle toward the shaft, embedding the pair of permanent magnets at equal intervals in the circumferential direction by the number of poles of the permanent magnet motor, and making the d-axis side surfaces of each pair of permanent magnets have the same polarity, and While a pair of adjacent permanent magnets are magnetized to different poles, the space between the pair of adjacent permanent magnets is widened to form an auxiliary pole near the q axis, and the outer periphery of the core is formed at the end of the permanent magnet. A hole is formed at the cutout or the same end, a hole of a flux burr is formed at the shaft side end of the pair of permanent magnets, and the outer periphery of the core is cut out around the d-axis to form a groove-shaped cutout. Forming a magnet torque and It is characterized in that so as to generate the reluctance torque.

[0010] The cutout portion may have an inverted arc shape or an inverted V shape.
It is preferable to secure a magnetic path from at least one q-axis to the other q-axis of the magnetic flux from the stator at least. As a result, the magnetic path from one d-axis to the other d-axis of the magnetic flux from the stator includes not only the permanent magnet but also the cutout of the air layer, so that the d-axis and q-axis inductance differences increase. As a result, the reluctance torque increases.

It is preferable that a rivet for fixing the core is passed through a region between the pair of permanent magnets and the cutout portion, and the rivet is made of a magnetic material. Thus, the core is fixed, and is not affected by the magnetic flux from one q-axis to the other q-axis, and the generation of the reluctance torque is not adversely affected.

The material of the first and second permanent magnets may be a ferrite magnet or a rare earth magnet. Thereby, an adaptive motor can be realized in consideration of low cost or high torque.

It is preferable that the rotor punches out the electromagnetic steel sheet by an automatic press, and at the same time, automatically laminates the magnetic steel sheet in a mold, and embeds the permanent magnet in a hole punched out by the automatic press.
As a result, the conventional press working can be used, so that the manufacturing cost does not need to be increased.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described in detail with reference to FIG. In the figure, the same parts as those in FIG. 9 are denoted by the same reference numerals, and the duplicate description will be omitted.

FIGS. 1 and 2 show a rotor 10 of a three-phase four-pole permanent magnet motor according to a first embodiment of the present invention.
Is a pair of the permanent magnets 11a and 11b having a rectangular cross section, which are positioned in a V-shape with an obtuse angle, the vertex of the obtuse angle is directed toward the shaft 4, and the pair of permanent magnets 11a and 11b is connected to the pole number (4 Pole), the flux barrier hole 12 is formed at the circumferential end of the permanent magnets 11a and 11b at a regular interval in the circumferential direction, and a hole 12 of the flux barrier to be shared is formed. It is formed by cutting into a shape and forming a groove-shaped cutout 13.

The pair of permanent magnets 1 of the rotor 10
1a and 11b are magnetized in the direction perpendicular to the side of the rectangular cross section, and the opposite side (d-axis side surface) has the same polarity, and the adjacent permanent magnets 11a and 11b have the opposite polarity. I have. Thereby, the four poles of the motor are formed on the d-axis by the permanent magnets 11a and 11b, and when a current in the q-axis direction perpendicular to the d-axis flows, a magnet torque is generated.

Since the holes 12 can prevent short-circuit and leakage of the magnetic flux of the permanent magnets 11a and 11b, the magnet torque increases. Therefore, even if the amount of magnets used for the pair of permanent magnets 11a and 11b is slightly reduced as compared with the conventional example, the magnet torque can be made approximately equal to the conventional one.

The cutout 13 forms a groove by partially cutting the outer periphery of the rotor 10, and secures a path of the magnetic flux from one q-axis to the other q-axis of the magnetic flux from the stator 1. It should be as shallow as possible. In addition, the cutting section 13
May be not only an inverted arc shape but also an inverted V shape or a bathtub shape described later so as to secure at least the magnetic path.

Thus, a magnetic path from one q-axis to the other q-axis is secured, and one d-axis is connected to the other d-axis.
Since the air layer holes 12 are interposed with respect to the magnetic flux to the shaft, d
The difference between the axis and q-axis inductances is larger than in the conventional example, and as a result, the reluctance torque is larger than in the conventional example. Therefore, the maximum torque (total torque) does not decrease even if the magnet usage of the pair of permanent magnets 11a and 11b is reduced by the increase in the reluctance torque.

Further, a ferrite magnet or a rare earth magnet is used as a material for the permanent magnets 11a and 11b. The use of a ferrite magnet is effective in reducing the cost of the motor, and the use of a rare earth magnet is effective in increasing the torque and reducing the size of the motor. Therefore, various adaptive motors can be obtained in consideration of cost, torque, and the like.

Here, the manufacture of the rotor 10 will be described. A core laminating method (automatic laminating method) in which an electromagnetic steel sheet is punched out by an automatic press using a core press die and integrally formed in the die is adopted. I do.

As shown in FIGS. 2 and 3, in this press working step, the core of the rotor 10 is punched out, but the hole (center hole) of the shaft 4, the hole for embedding the permanent magnets 11a and 11b, and the cutout portion 12 are formed. The core sheets 10a thus punched out are laminated, caulked, and fixed. Then, the permanent magnets 11a, 1a are formed by IPM in the holes of the core of the rotor 10 obtained by automatically pressing and laminating by the automatic laminating method.
1b is embedded and magnetized. FIG. 3 is a schematic side view in the q-axis direction of FIG.

The width between the hole 12 and the permanent magnets 11a and 11b is equal to or more than the thickness t of the core sheet 10a (for example, t to 3t), and similarly, the hole 12 and the outer periphery of the rotor 10 (core outer periphery). ) Is equal to or more than the thickness t (for example, t to 3t). As a result, burrs and the like are not generated at the time of core manufacturing described later, the yield of core manufacturing can be improved, and the manufacturing cost can be reduced. In addition, the mechanical strength of the core can be maintained, and particularly, the core strength during rotation is maintained, and the reliability of the motor is improved.

Further, as shown in FIG.
A lid (terminal plate) 14 is attached to both ends of the laminated core, and a rivet 15 for caulking is passed so that the cores a and 11b do not move in the core and the core does not jump out. The rivet 15 is passed through a region between the permanent magnets 11a and 11b, and is made of a material such that a magnetic flux from one q-axis to the other q-axis does not have an adverse effect (for example, disturbance). A magnetic material having good magnetic permeability is used. In addition, when the core is swaged not only through the rivet 15 but also when the core sheet 10a is pressed and laminated, the fixing strength of the core can be further increased.

Further, if the high-torque, high-efficiency motor is used as, for example, a compressor motor of an air conditioner, the cost of the air conditioner can be reduced and the operating efficiency of the air conditioner can be increased. it can. The stator 1 has, for example, a U-phase winding, a W-phase inner diameter winding, and a V-phase intermediate winding. Further, the three-phase (U-phase, V-phase and W-phase) armature windings are applied to the 24-slot stator 1, but the number of slots and the armature windings may be different.

FIG. 4 is a schematic plan view of a rotor constituting a permanent magnet motor according to a second embodiment of the present invention. In the drawings, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted. See FIG. 1 for the stator 1.

In FIG. 4, this rotor 20 has a pair of permanent magnets 21a and 21b embedded at positions where the obtuse angle forming the V-shape is smaller, instead of the permanent magnets 11a and 11b shown in FIGS. It becomes.

In this case, the permanent magnet 21 near the q axis
A predetermined width D1 is ensured between a and the permanent magnet 21b, that is, between the pair of adjacent permanent magnets 21a and 21b. Since the predetermined width D1 secures a magnetic path from one q-axis to the other q-axis of the magnetic flux from the stator 1 (dashed arrow in FIG. 4), an auxiliary pole (auxiliary projection) is provided near the q-axis. Pole) h is formed.

Further, a magnetic path width (predetermined width) D2 from one q-axis to the other q-axis is secured between the pair of permanent magnets 21a and 21b and the cutout portion 13. Thus, the auxiliary pole h is formed in the vicinity of the q-axis, and includes not only the magnetic path width D2 corresponding to the previous embodiment but also a predetermined width D1 as a magnetic path from one q-axis to the other q-axis. Thus, the difference between the d-axis and q-axis inductances becomes larger than in the previous embodiment, and the reluctance torque becomes larger. Therefore, even if the amount of magnets used by the pair of permanent magnets 21a and 21b is reduced as compared with the previous embodiment, the cost can be reduced without reducing the maximum torque of the permanent magnet motor.

In the case of manufacturing the rotor 20 having the above-described structure, the core laminating method (automatic laminating method) is applied as in the previous embodiment. Holes and the permanent magnets 21a,
The hole for embedding 21b and the cutout 13 are punched out, and the core sheet 10a punched out of these is laminated, caulked, and fixed. In the manufacture of the rotor 20, as described in the previous embodiment, in addition to embedding the permanent magnets 21a and 21b,
3, terminal plates 14 are attached to both ends in the same manner as in FIG.
Pass through.

FIG. 5 is a schematic plan view of a rotor showing a modification of the second embodiment of the present invention. In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted. See FIG. 1 for the stator 1.

In FIG. 5, the rotor 30 is formed by forming a groove cutout 31 cut into an inverted V-shape instead of the inverted arc-shaped cutout 13 shown in FIG. This cutout 3
1 is cut out, for example, in a straight line parallel to the long sides of the permanent magnets 21a and 21b, and secures a magnetic path from at least one q-axis of the magnetic flux from the stator 1 to the other q-axis.

As a result, in this modification, at least the same reluctance torque as in the above-described second embodiment is generated. Note that the manufacture of the rotor 30 may be the same as in the second embodiment, and a description thereof will be omitted.

FIG. 6 is a schematic plan view of a rotor showing a modification of the second embodiment of the present invention. In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted. See FIG. 1 for the stator 1.

In FIG. 6, the rotor 40 has a cut-out portion 41 cut out in a bathtub shape instead of the inverted arc-shaped cut portion 13 shown in FIG. Note that the bathtub shape is a curve formed by the bottom side and both oblique sides excluding the top side of the trapezoid. The cutout portion 31 is formed by cutting the hypotenuse, for example, as a straight line along the long sides of the permanent magnets 21a, 21b. At least the magnetic flux from one q-axis to the other q-axis of the magnetic flux from the stator 1 is obtained. Secure the road.

As a result, in this modification, at least the same reluctance torque as in the second embodiment described above is generated. Note that the manufacture of the rotor 30 may be the same as in the second embodiment, and a description thereof will be omitted.

As described above, according to the second embodiment and the two modifications, the reluctance torque can be increased as compared with the previous embodiment (first embodiment). The torque increases. Therefore,
Even if the amount of the permanent magnets 21a and 21b used is smaller than that of the first embodiment, the maximum torque of the permanent magnet motor can be kept as it is, and the cost can be reduced.

FIG. 7 is a schematic plan view of a rotor constituting a permanent magnet motor according to a third embodiment of the present invention. In the drawings, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description will be omitted. See FIG. 1 for the stator 1.

In FIG. 7, the rotor 50 is replaced with a pair of permanent magnets 5 at positions where the V-shaped obtuse angle is smaller, instead of the permanent magnets 11a and 11b shown in FIGS.
1a, 51b are embedded and each of the permanent magnets 51a, 51
hole 52 of the flux barrier and notch 5
3a and 53b are formed.

The hole 52 is formed in a substantially triangular shape at the end of the permanent magnets 51a and 51b on the shaft 4 side, and serves as a flux barrier for the pair of permanent magnets 51a and 51b. The side of the hole 52 is parallel to the short sides of the permanent magnets 51a and 51b. Note that for the same reason as in the first embodiment,
The distance between the hole 52 and the permanent magnets 51a and 51b is equal to or more than the thickness t of the core sheet 10a (for example, t to 3t).

The notches 53a and 53b replace the holes 12 shown in FIG. 1 and FIG.
The flux barrier 51b has a substantially triangular cutout at the outer peripheral end of the core 51b. The sides of the notches 53a and 53b are parallel to the short sides of the permanent magnets 51a and 51b, and the other sides are parallel to the q-axis. For the same reason as in the first embodiment, the notches 53a and 53b and the permanent magnets 51a and 51b are used.
The interval between the core sheet 10a and the core sheet b is equal to or more than the thickness t of the core sheet 10a (for example, t to 3t).

As described above, by forming the flux barrier of the air layer on the short sides of the permanent magnets 51a and 51b, short-circuit and leakage of the magnetic flux of the permanent magnets 51a and 51b can be prevented, and the magnet torque can be reduced. Will increase. Further, similarly to the second embodiment,
An auxiliary pole h is formed near the q-axis, and a magnetic path from one q-axis to the other q-axis of the magnetic flux from the stator 1 is secured.

Accordingly, in the present embodiment, the difference between the d-axis and q-axis inductances is larger than in the first embodiment, and the reluctance torque is larger. Due to the increase in the reluctance torque and the increase in the magnet torque described above, even if the magnet usage of the permanent magnets 51a and 51b is reduced as compared with the previous embodiment, the maximum torque of the permanent magnet motor does not decrease and the permanent magnet motor does not decrease. The cost can be increased, and the torque and efficiency can be increased.

FIG. 8 is a schematic plan view of a rotor of a permanent magnet motor showing a modification of the third embodiment of the present invention. In the drawing, the same parts as those in FIG. 7 are denoted by the same reference numerals, and the duplicate description will be omitted. See FIG. 1 for the stator 1.

In FIG. 8, the rotor 60 has holes 61a, 61b formed at the ends of the permanent magnets 51a, 51b instead of the notches 53a, 53b. The holes 61a, 6
1b is punched into a substantially triangular shape.
The interval between 61b and the outer periphery of the core is set to be equal to or more than the thickness t of the core sheet 10a (for example, t to 3t) for the above-described reason.

As described above, according to this modification, the magnet torque and the reluctance torque can be increased in the same manner as in the previous embodiment (third embodiment), so that the maximum torque of the permanent magnet motor increases. . Therefore, even if the magnet usage of the permanent magnets 21a and 21b is reduced from that of the first embodiment, the maximum torque of the permanent magnet motor can be kept as it is, that is, the cost can be reduced.

When manufacturing the rotor 50 or the rotor 60 having the above-described structure, the core laminating method (automatic laminating method) is applied as in the previous embodiment, and the cores of the rotors 50 and 60 are pressed in the pressing step. When punching the shaft 4
Holes, holes for embedding permanent magnets 51a and 51b, holes 52 and notch portions 53a and 53b serving as flux barriers.
Alternatively, the holes 61a and 61b are punched, and the core sheets 10a obtained by punching the holes are stacked, caulked, and fixed.

In the manufacture of the rotors 50 and 60, as described in the above-described embodiment, the permanent magnets 51a and 51b are used.
3, rivets 15 are passed through with terminal plates 14 attached to both ends as in FIG. 3. In addition, in the third embodiment and the modification of the embodiment, the shape of the cutout portion 13 may be the inverted V shape or the bathtub shape shown in the modification of the second embodiment.

[0049]

According to the present invention described above, the following effects can be obtained. According to the present invention, a pair of permanent magnets having a rectangular cross section are positioned in a V-shape with an obtuse angle on the rotor of the permanent magnet electric motor, and the apex of the obtuse angle is directed toward the shaft. Since the core is embedded at equal intervals in the circumferential direction by the number of poles of the motor and the outer periphery of the core is cut out near the d-axis to form a groove-shaped cutout, the main magnet torque is generated and the reluctance torque is increased. can do.
Therefore, even if the amount of permanent magnet used is reduced by an amount corresponding to the increase in the reluctance torque, the maximum torque of the permanent magnet motor does not decrease, and high torque and high efficiency can be achieved at low cost. This has the effect.

According to the present invention, a pair of adjacent permanent magnets are spaced apart from each other to form an auxiliary pole near the q-axis, and a magnetic path is secured between the pair of permanent magnets and the cutout near the d-axis. Therefore, there is an effect that reluctance torque can be further increased and, consequently, contribute to higher torque and higher efficiency at lower cost.

According to the present invention, since a hole or a cutout of a flux barrier is formed at the end of the pair of permanent magnets to prevent short-circuit leakage of the magnetic flux of the permanent magnet, the magnet torque can be increased. At the same time, even if the magnet usage of the permanent magnet is reduced by the increased amount, the maximum torque of the permanent magnet motor does not decrease. Therefore, there is an effect that it contributes to high torque and high efficiency at low cost.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a permanent magnet electric motor according to a first embodiment of the present invention.

FIG. 2 is a schematic plan view of a rotor for explaining the permanent magnet motor shown in FIG.

FIG. 3 is a schematic side view of a rotor for explaining the permanent magnet electric motor shown in FIG. 1;

FIG. 4 is a schematic plan view of a rotor of a permanent magnet motor showing a second embodiment of the present invention.

FIG. 5 is a schematic plan view of a rotor of a permanent magnet motor showing a modification of the second embodiment shown in FIG. 4;

FIG. 6 is a schematic plan view of a rotor of a permanent magnet motor showing a modification of the second embodiment shown in FIG. 4;

FIG. 7 is a schematic plan view of a rotor of a permanent magnet motor showing a third embodiment of the present invention.

FIG. 8 is a schematic plan view of a rotor of a permanent magnet motor showing a modification of the third embodiment shown in FIG. 7;

FIG. 9 is a schematic plan view of a conventional permanent magnet motor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Stator 4 Shaft 10, 20, 30, 45, 50, 60 Rotor 10a Core sheet 11a, 11b, 21a, 21b, 51a, 51b Permanent magnet 12, 52, 61a, 61b Hole (flux barrier of air layer) 13 , 31, 41 Cutout 53a, 53b Cutout h Complementary pole t Core sheet thickness

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AA05 AB07 AC03 AC06 AE08 5H619 AA01 AA07 BB01 BB06 BB22 BB24 PP02 PP04 PP05 PP08 5H621 AA03 GA01 GA04 GA15 HH01 HH09 JK02 5H622 AA03 CA02 CA07 CA13 CB03 PP01 CB03 PP10 QB05

Claims (7)

[Claims] 1. A permanent magnet motor having a rotor inside a stator that generates a rotating magnetic field, wherein the rotor includes:
A pair of permanent magnets having a rectangular cross section is positioned in a V-shape with an obtuse angle, and the apex of the obtuse angle is directed toward the shaft.
The pair of permanent magnets are embedded at equal intervals in the circumferential direction by the number of poles of the permanent magnet motor, and the d-axis side surfaces of each pair of permanent magnets have the same polarity and adjacent pair of permanent magnets are different. Magnetizing the poles, forming a flux barrier hole near the q-axis at the end of the core outer peripheral side of the core, and cutting the outer periphery of the core near the d-axis to form a groove-shaped cutout. A permanent magnet electric motor characterized by generating a magnet torque and a reluctance torque. 2. A permanent magnet motor having a rotor inside a stator that generates a rotating magnetic field, wherein the rotor includes:
A pair of permanent magnets having a rectangular cross section are positioned in a V-shape at an obtuse angle with the apex of the obtuse angle facing the shaft, and the pair of permanent magnets are equally spaced in the circumferential direction by the number of poles of the permanent magnet motor. Embedded, d for each pair of permanent magnets
The side surfaces of the shaft are made to have the same polarity, and a pair of adjacent permanent magnets are magnetized to different polarities, while the space between the pair of adjacent permanent magnets is widened to form an auxiliary pole near the q axis, A permanent magnet electric motor characterized in that a groove-shaped cut portion is formed by cutting the outer periphery of the core in the vicinity to generate a magnet torque and a reluctance torque. 3. A permanent magnet motor having a rotor inside a stator that generates a rotating magnetic field, wherein the rotor includes:
A pair of permanent magnets having a rectangular cross section are positioned in a V-shape at an obtuse angle with the apex of the obtuse angle facing the shaft, and the pair of permanent magnets are equally spaced in the circumferential direction by the number of poles of the permanent magnet motor. Embedded, d for each pair of permanent magnets
The side surfaces of the shafts have the same polarity, and a pair of adjacent permanent magnets are magnetized to different polarities, while the space between the pair of adjacent permanent magnets is widened to form an auxiliary pole near the q-axis. At the end of the magnet, a hole is formed at the notch or the same end where the outer periphery of the core is cut off, a hole of a flux burr is formed at the shaft side end of the pair of permanent magnets, and the core is formed near the d axis. A permanent magnet electric motor wherein an outer periphery is cut out to form a groove-shaped cutout portion to generate a magnet torque and a reluctance torque. 4. The notch has an inverted arc shape, an inverted V-shape, or a bathtub shape so as to secure a magnetic path from at least one q-axis of the magnetic flux from the stator to the other q-axis. The permanent magnet electric motor according to claim 1, 2 or 3, wherein: 5. A rivet for fixing the core in a region between the pair of permanent magnets and the cutout portion, and the rivet is made of a magnetic material.
The permanent magnet electric motor according to 1. 6. The permanent magnet motor according to claim 1, wherein the material of the first and second permanent magnets is a ferrite magnet or a rare earth magnet. 7. The rotor according to claim 1, wherein the rotor is punched out of an electromagnetic steel plate by an automatic press, and is automatically laminated in a mold, and the permanent magnet is embedded in a hole punched out by the automatic press. 7. The permanent magnet electric motor according to 4, 5, or 6.