JPH11275783A - Permanent magnet embedded rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a higher efficient permanent magnet motor by fully and effectively utilizing a reluctance torque, without decreasing the magnetic flux by a permanent magnet. SOLUTION: In a rotor 11, a flat part 16 is provided outside an arc of a punched hole for embedding a permanent magnet located at the inner-periphery side of the rotor, and a magnetic path width Xb of a magnetic path 15b that exists between areas near the surface of a rotor core 12 of punched holes 13a and 13b for embedding a permanent magnet in two layers within the same magnetic pole is nearly the same as a magnetic path width X of a magnetic path 15c, that exists between areas near the rotor core surface of the punched hole for embedded a permanent magnet which is located at the inner-periphery side of an adjacent magnetic pole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a permanent magnet embedded rotor for improving motor efficiency by effectively utilizing not only magnet torque but also reluctance torque.

[0002]

2. Description of the Related Art Conventionally, a permanent magnet motor that realizes high efficiency by embedding a permanent magnet in a rotor core and using a magnet torque in combination with a reluctance torque has been known. FIG.
1 is a cross-sectional view of a permanent magnet motor disclosed in Japanese Patent No. 331783. The rotor 51 has a substantially cylindrical shape that is substantially coaxial with a substantially annular stator (not shown), has four magnetic poles facing the inner peripheral surface of the stator, and has a bearing that rotates freely around the shaft 2. Supported by such. The rotor core 52 is made of a high magnetic permeability material such as iron or laminated electromagnetic steel plates, and has a circular arc-shaped punched hole 53a, 53b for embedding permanent magnets on the inner peripheral side of the rotor.
Punch holes 53a, 53b for burying permanent magnets
Are embedded with permanent magnets 54a and 54b, respectively. The rotor 51 is rotated by a magnetic pole of the rotor being attracted or repelled to a rotating magnetic field formed by a current flowing through a winding formed as a three-phase winding on the stator.

In this configuration, since a magnetic path of iron 55b exists between the two layers of punched holes for embedding permanent magnets 53a and 53b in the same magnetic pole, the magnetic flux passing through the rotor magnetic pole at right angles Ld ( Ld <Lq holds between d-axis inductance) and the ease Lq (q-axis inductance) of the magnetic flux passing through the boundary between the rotor magnetic poles. The number of layers per pole of the punched hole for embedding permanent magnets is Lq-L
It is disclosed in Japanese Patent Application Laid-Open No. Hei 8 (1994) that values such as d, torque, and magnet magnetic flux are saturated in two layers and do not increase even in three or more layers.
As described in JP-A-333183.

In general, the torque of a permanent magnet motor is T = Pn ｛ψa ·, where Pn is the number of pole pairs, ψa is the flux linkage, I is the stator winding current, and β is the leading phase angle (electrical angle) of the current I.
I · cosβ + 0.5 (Lq−Ld) I2 · sin2
The first term represents magnet torque (active torque), and the second term represents reluctance torque.
Therefore, when the relationship of Ld <Lq is satisfied, the current advancing control is performed, β> 0, and reluctance torque is generated. By appropriately setting the value of β, the same current can be obtained.
It is possible to generate a larger torque than when only the magnet torque is used.

[0005]

However, the above configuration has the following disadvantages.

In order to increase the pole surface area of the permanent magnet,
Punched hole 53a for embedding permanent magnets located on inner circumferential side of rotor
The arc radii of the permanent magnets are configured to be sufficiently large, and the outsides of the arcs of the permanent magnet burying punched holes 53a located on the inner peripheral side of the rotor of the adjacent magnetic poles are close to each other, and a sufficient magnetic path has not been secured. Therefore, the reluctance torque could not be fully utilized.

The present invention solves the above-mentioned drawbacks, and provides a highly efficient permanent magnet motor that makes full use of reluctance torque effectively without reducing the magnetic flux generated by the permanent magnet.

[0008]

Means for Solving the Problems In a permanent magnet embedded rotor in which two layers of permanent magnets are embedded in the radial direction per pole, a gap between two punched holes for embedding permanent magnets in the same magnetic pole near the surface of the rotor core. The width of the magnetic path of the iron existing in the rotor is substantially the same as the width of the magnetic path of the iron existing between the vicinity of the rotor core surface of the punched hole for embedding the permanent magnet located on the inner circumferential side of the rotor of the adjacent magnetic pole.

[0009]

DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, two layers of permanent magnets are buried radially per pole in a substantially cylindrical rotor core made of a high magnetic permeability material such as iron or laminated electromagnetic steel sheets. A permanent magnet-embedded rotor having at least one permanent magnet embedded in each of the punched holes for embedding permanent magnets, wherein both ends of the punched hole for embedding permanent magnets are near the rotor core surface. To
The magnetic path width of the iron existing between the two cores in the same magnetic pole near the rotor core surface of the punched holes for embedding permanent magnets is equal to the rotor core surface of the punched holes for embedding permanent magnets located on the inner circumferential side of the rotor of adjacent magnetic poles. The permanent magnet embedded rotor which is substantially the same as the narrowest part of the magnetic path width of the iron existing between adjacent parts, and between the two layers near the rotor core surface of the two-layered permanent magnet embedded punched holes in the same magnetic pole. It is possible to effectively use not only the existing magnetic path of iron but also the magnetic path of iron existing between the vicinity of the rotor core surface of the punched hole for embedding permanent magnets located on the inner peripheral side of the rotor of the adjacent magnetic pole. , The reluctance torque can be increased.

According to a second aspect of the present invention, the magnetic pole area of the permanent magnet embedded in the punched hole for embedding the permanent magnet located on the inner peripheral side of the rotor is embedded in the punched hole for embedding the permanent magnet located on the outer peripheral side of the rotor. The permanent magnet-embedded rotor according to claim 1, wherein the permanent magnet has a magnetic pole area larger than the magnetic pole area of the permanent magnet, and has a function of suppressing generation of an ineffective short-circuit magnetic flux at an end face of the permanent magnet located on the outer peripheral side of the rotor.

According to a third aspect of the present invention, there is provided the permanent magnet embedded rotor according to the first aspect, wherein the punched hole for embedding the permanent magnet has an arc shape which is convex on the inner peripheral side of the rotor. Therefore, the amount of magnetic flux generated by the permanent magnet can be increased, and the magnetic path between the punched holes for the two-layer permanent magnet has an arc shape, so that local magnetic saturation can be prevented.

According to a fourth aspect of the present invention, there is provided the permanent magnet embedded rotor according to the third aspect, wherein the permanent magnet has an arc shape which is convex toward the inner peripheral side of the rotor and has a gap large enough to be inserted into the hole for embedding the permanent magnet. Thus, the magnetic flux of the permanent magnet can be effectively used.

According to a fifth aspect of the present invention, there is provided a permanent magnet embedding punched hole located on the inner peripheral side of the rotor of adjacent magnetic poles, and a magnetic path width of iron existing near the surface of the rotor core is constant. 4. The permanent magnet-embedded rotor according to claim 3, wherein a flat portion is provided near an end outside the arc of the punched hole for embedding the permanent magnet, and the magnetic pole area of the adjacent permanent magnet is kept large while keeping the magnetic pole area of the permanent magnet large. The magnetic path width of iron existing between the punched holes for embedding permanent magnets located in the vicinity of the rotor core surface can be secured, and the reluctance torque can be increased.

According to a sixth aspect of the present invention, when the number P of rotor magnetic poles is 4 or more and the outer diameter of the rotor is r, the arc center of the punched hole for embedding the permanent magnet is 0.8 mm from the center of the rotor.
5 r / cos (180 / P) or less 0.7 r / cos (1
80 / P) or higher, wherein the permanent magnet embedded rotor according to claim 5, wherein the amount of magnetic flux can be increased by enlarging the magnetic pole area of the permanent magnet.

According to a seventh aspect of the present invention, there is provided the permanent magnet embedded rotor according to the first aspect, wherein one or more plate-shaped permanent magnets are embedded in the punched holes for embedding the permanent magnets. Therefore, a highly efficient motor can be manufactured at low cost.

According to the present invention, two layers of punched holes for burying permanent magnets in the radial direction per pole are provided inside a substantially cylindrical rotor core made of a high magnetic permeability material such as iron or laminated magnetic steel sheets. In a permanent magnet embedded rotor having an axial direction and one or more permanent magnets embedded in each of the permanent magnet embedded punched holes, both ends of the permanent magnet embedded punched holes extend to near the rotor core surface, and Among the magnetic path widths of the iron existing between the vicinity of the rotor core surface of the two layers of the punched holes for embedding permanent magnets in the magnetic pole, the rotor rotation forward side is Xf, the rotor rotation backward side is Xb, and the rotor of the adjacent magnetic pole is Assuming that Xc is the narrowest part of the magnetic path width of the iron present between the punched holes for embedding permanent magnets located on the inner periphery and near the rotor core surface, Xf>Xc> Xb Among the iron magnetic paths existing between the two surfaces of the punched holes for burying permanent magnets in the same magnetic pole near the rotor core surface, the magnetic saturation on the rotor rotation forward side where the magnetic flux density is particularly high is eliminated, It is possible to effectively use the magnetic path of the iron existing between the punched holes for burying the permanent magnets located on the inner peripheral side of the rotor of the adjacent magnetic pole and near the rotor core surface, thereby increasing the reluctance torque.

According to a ninth aspect of the present invention, the magnetic pole area of the permanent magnet embedded in the punched hole for embedding permanent magnets located on the inner peripheral side of the rotor is embedded in the punched hole for embedding permanent magnets located on the outer peripheral side of the rotor. The permanent magnet-embedded rotor according to claim 8, wherein the rotor has a function of suppressing generation of an invalid short-circuit magnetic flux at an end face of the permanent magnet located on the outer peripheral side of the rotor.

According to a tenth aspect of the present invention, there is provided the permanent magnet embedded rotor according to the eighth aspect, wherein the perforated hole for embedding the permanent magnet has an arc shape that is convex on the inner peripheral side of the rotor. Since the magnetic path between them has an arc shape that is wider toward the rotor rotation forward side, local magnetic saturation can be prevented, and a uniform magnetic flux density distribution can be realized.

According to an eleventh aspect of the present invention, there is provided the permanent magnet embedded rotor according to the tenth aspect, wherein the permanent magnet has a circular arc shape which is convex toward the inner peripheral side of the rotor and has a gap large enough to be inserted into the punched hole for embedding the permanent magnet. Thus, the magnetic flux of the permanent magnet can be effectively used.

According to a twelfth aspect of the present invention, the width of the magnetic path of the iron existing between the punched holes for embedding permanent magnets located on the inner circumferential side of the rotor of adjacent magnetic poles and near the surface of the rotor core is constant. 11. The permanent magnet embedded rotor according to claim 10, wherein a flat portion is provided near an outer end portion of the punched hole for embedding the permanent magnet, wherein the magnetic pole area of the adjacent permanent magnet is kept large while keeping the magnetic pole area of the permanent magnet large. The magnetic path width of iron existing between the punched holes for embedding permanent magnets located in the vicinity of the rotor core surface can be secured, and the reluctance torque can be increased.

According to a thirteenth aspect, the number of rotor magnetic poles P
Is not less than 4 and the outer diameter of the rotor is r, the center of the arc of the perforated hole for embedding the permanent magnet is 0.
85r / cos (180 / P) or less 0.7r / cos
The permanent magnet embedded rotor according to claim 12, which is located at a position of (180 / P) or more, wherein the amount of magnetic flux can be increased by increasing the magnetic pole area of the permanent magnet.

According to a fourteenth aspect of the present invention, there is provided the permanent magnet embedded rotor according to the seventh aspect, wherein one or more plate-shaped permanent magnets are buried in the punched holes for burying the permanent magnets. Therefore, a highly efficient motor can be manufactured at low cost.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) Embodiment 1 will be described with reference to FIG.

FIG. 1 is a sectional view showing a rotor according to the first embodiment of the present invention. The rotor 11 has a substantially cylindrical shape that is substantially coaxial with a substantially annular stator (not shown), has four magnetic poles facing the inner peripheral surface of the stator, and has a bearing that rotates freely around the shaft 2. Supported by such. The rotor core 12 is made of a material having a high magnetic permeability such as iron or laminated electromagnetic steel plates, and has two arc-shaped perforated holes 13a and 13b for embedding permanent magnets, which are convex on the inner peripheral side of the rotor. And the punched holes 13a, 1
Permanent magnets 14a and 14b are buried in 3b so that they can be inserted into the permanent magnet burying holes. Usually, the gap is suitably about 1 to 3% of the width of the permanent magnet.

The rotor is rotated by a magnetic pole of the rotor attracting or repelling to a rotating magnetic field formed by a current flowing through a winding formed as a three-phase winding on the stator.

In this configuration, both ends of the perforated holes 13a and 13b for embedding permanent magnets extend to near the rotor core surface,
Magnetic path width Xb of iron 15b existing between two layers near the surface of the rotor core of punched holes for embedding permanent magnets in the same magnetic pole
Are substantially the same as the magnetic path width Xc of the iron 15c existing between the adjacent punched holes for burying permanent magnets located on the inner circumferential side of the rotor near the rotor core surface. The values of Xb and Xc need not be exactly the same, and a deviation of about ± 10% is allowed.

The magnetic pole area of the permanent magnet 14a buried in the permanent magnet burying hole 13a located on the inner peripheral side of the rotor has the same magnetic pole area as that of the permanent magnet burying hole 13b located on the rotor outer peripheral side. 14b is larger than the magnetic pole area.

Further, assuming that the rotor radius is r, the center of the arc of the punched holes 13a and 13b for embedding the permanent magnets is at a position of 0.85r / cos (180 / P) or less from the center of the rotor, Compared to the case with magnets,
The pole surface area can be increased. If the distance from the center of the arc of the punched hole for embedding the permanent magnet to the center of the rotor is too small, the magnetic pole on the rotor surface becomes narrow and magnetic saturation occurs, so that 0.7 r / cos (180 / P) or more is required. desirable. FIG. 2 shows the distance from the center of the rotor to the center of the arc and the magnetic pole area per unit length calculated for the permanent magnet 14a located on the inner peripheral side of the rotor and the permanent magnet 14b located on the outer peripheral side of the rotor. FIG. 3 shows the distance from the center of the rotor to the center of the arc and the magnetic pole opening angles θa and θb calculated for the permanent magnet 14a located on the inner peripheral side of the rotor and the permanent magnet 14b located on the outer peripheral side of the rotor. In each case,
The permanent magnet thicknesses ta and tb are about 1/6 of the rotor radius,
The magnetic path width Xb between the two layers of punched holes for embedding permanent magnets was set to about 1/14 of that of the rotor, and the radius of the punched holes for embedding permanent magnets was made as large as possible. This is an appropriate value in consideration of demagnetization and the like when a ferrite magnet is used. The magnetic pole area decreases as the distance from the center of the rotor to the center of the arc increases, but the magnetic pole area on the outer peripheral side of the rotor particularly decreases greatly when the distance from the center of the rotor to the center of the arc exceeds 1.2. Further, the magnetic pole opening angle θa of the permanent magnet on the inner diameter side of the rotor is desirably 60 ° (electrical angle 120 °) or more, but it is understood that the distance from the center of the rotor to the center of the arc is 1 or more. Therefore, the distance from the center of the rotor to the center of the arc is optimally 1 or more and 1.2 or less. In this case, since the rotor is a four-pole rotor, if a rotor other than the four-pole rotor is similarly considered, the distance from the rotor center to the arc center is 0.7
r / cos (180 / P) or more and 0.85 r / cos (1
80 / P) or less.

When the arc radius of the punched hole for embedding permanent magnets is increased, the vicinity of the rotor core surface of the punched hole for embedding permanent magnets located on the inner circumferential side of the rotor of the adjacent magnetic pole is close to the inner circumferential side of the rotor. In order to keep the magnetic path width Xc of the iron 15c existing near the surface of the rotor core of the punched hole 13a for embedding the permanent magnet located at a position near the end outside the arc of the punched hole for embedding the permanent magnet, Is provided. As a result, while keeping the magnetic pole area of the permanent magnet large, the magnetic path width Xc of the iron 15c existing between the adjacent magnetic poles near the rotor core surface of the punched holes for burying permanent magnets located on the inner circumferential side of the rotor is secured. In addition, the reluctance torque can be increased.

With this configuration, not only the magnetic path of the iron 15b existing between the two surfaces of the punched holes for embedding permanent magnets in the same magnetic pole near the surface of the rotor core but also on the inner circumferential side of the rotor of the adjacent magnetic pole. The magnetic path of the iron 15c existing between the punched holes for embedding permanent magnets near the rotor core surface can also be effectively used, and Lq-Ld can be increased, so that the reluctance torque can be increased. Since the magnetic pole surface area is large, the magnet torque can be increased. Therefore, a highly efficient permanent magnet motor can be provided.

FIG. 4 shows a result of a magnetic field analysis when a current is applied to the motor using the rotor with embedded permanent magnets in the present embodiment and the motor is operated. The curve shown in FIG. 4 is a magnetic flux line and indicates the flow of magnetic flux. Since there is an iron magnetic path wide enough to prevent magnetic saturation between the punched holes for embedding permanent magnets located on the inner peripheral side of the rotor of adjacent magnetic poles and near the rotor core surface, the magnetic flux between the magnetic poles is smooth. It can be seen that it extends over the stator and effectively contributes to torque generation. In the conventional permanent magnet embedded rotor shown in FIG. 9, magnetic saturation occurs between the magnetic poles, and the magnetic flux between the magnetic poles does not sufficiently contribute to the torque. With this configuration, the torque is increased by 5 to 8% as compared with the conventional example by the same current,
The motor efficiency was improved by about 0.5 to 1%.

The permanent magnet 1 located on the inner peripheral side of the rotor
The arc centers of the permanent magnet 4b and the permanent magnet 14b located on the outer peripheral side of the rotor need not be the same.

(Embodiment 2) Embodiment 2 will be described with reference to FIG.

FIG. 5 is a sectional view showing a rotor according to the second embodiment of the present invention. Punching holes 23a for embedding permanent magnets,
23b, flat permanent magnets 24a1, 24a2, 24b
Two 1, 24b2 are buried. Other configurations and operations are the same as in the first embodiment, and a description thereof will not be repeated. By using a plate magnet with good productivity, the cost can be reduced and an efficient motor can be provided.

(Embodiment 3) Embodiment 3 will be described with reference to FIG. FIG. 6 is a cross-sectional view illustrating a rotor according to the third embodiment of the present invention.

The rotor with embedded permanent magnets in this embodiment has two poles, and the punched holes 33a, 33b for embedding permanent magnets.
The plate-shaped permanent magnets 34a1, 34a2, 34b1, 3
4b2 are buried. Other configurations and operations are the same as in the first embodiment, and a description thereof will not be repeated. By using a plate magnet with good productivity, the cost can be reduced and an efficient motor can be provided. The permanent magnet may be formed in a V shape.

By using two poles, the frequency of the driving current becomes half of that of four poles, so that iron loss can be reduced.

Embodiment 4 Embodiment 4 will be described with reference to FIG.

FIG. 7 is a sectional view showing a rotor according to a fourth embodiment of the present invention. The rotor 41 has a substantially cylindrical shape that is substantially coaxial with a substantially annular stator (not shown), has four magnetic poles facing the inner peripheral surface of the stator, and has a bearing that rotates freely around the shaft 2. Supported by such. The rotor core 42 is made of a magnetically permeable material such as iron or laminated electromagnetic steel plates, and has two arc-shaped perforated holes 43a and 43b for embedding permanent magnets, which are convex on the inner peripheral side of the rotor. And the punched holes 43a, 43 for embedding the permanent magnets.
Permanent magnets 44a and 44b are buried in 3b with gaps enough to be inserted into the permanent magnet burying holes. Usually, the gap is suitably about 1 to 3% of the width of the permanent magnet.

The rotor 41 rotates counterclockwise as the magnetic poles of the rotor are attracted or repelled by a rotating magnetic field formed by a current flowing through a winding formed as a three-phase winding on the stator.

In this configuration, both ends of the punched holes 43a and 43b for embedding permanent magnets extend to near the rotor core surface,
Of the magnetic path widths of the irons 45f and 45b existing between the two surfaces of the punched holes for burying permanent magnets in the same magnetic pole near the surface of the rotor core, the rotor rotation forward side is defined as Xf, and the rotor rotation backward side is defined as Xb. Xf> X, where Xc is the magnetic path width of the iron 45c existing between the punched holes for embedding permanent magnets located on the inner circumferential side of the rotor and the vicinity of the rotor core surface.
c> Xb. In the present embodiment, the center of the arc of the permanent magnet 44a located on the inner peripheral side of the rotor is on the rotor rotation forward side as compared with the center of the arc of the permanent magnet 44b located on the outer peripheral side of the rotor.

The magnetic pole area of the permanent magnet 44a embedded in the punched hole 43a for embedding the permanent magnet located on the inner peripheral side of the rotor is smaller than the permanent magnet embedded in the punched hole 43b for embedding the permanent magnet located on the outer peripheral side of the rotor. 44b is larger than the magnetic pole area. Therefore, the permanent magnet 4 located on the inner circumferential side of the rotor
Not all of the magnetic flux emitted from the inner peripheral side of the arc of 3a goes to the outer peripheral side of the arc of the permanent magnet 43b located on the outer peripheral side of the rotor. Cross the road to the stator. Therefore, since a large amount of magnetic flux passes from the magnetic path between the punched holes for burying permanent magnets on the rotor rotation advance side to the stator, Xf needs to be large. It is appropriate that Xf is 1.5 to 2 times Xc, and Xb can be small because magnetic flux hardly passes therethrough. As a result, local saturation of magnetic flux can be prevented, iron loss of the rotor can be reduced, and reluctance torque can be further increased. It is effective when the rotation direction is one direction. Other configurations and operations are the same as those in the first embodiment, and a description thereof will be omitted.

FIG. 8 shows the results of a magnetic field analysis when a current is applied to the motor using the permanent magnet embedded rotor in this embodiment and the motor is operated.

Among the iron magnetic paths existing between the two layers of the punched holes for burying permanent magnets in the same magnetic pole near the surface of the rotor core, the magnetic flux passing the rotor rotation forward side is the largest, and then the magnetic flux of the adjacent magnetic pole is The punched holes for embedding permanent magnets located on the inner circumferential side of the rotor are iron magnetic paths existing between the surfaces near the rotor core surface. Therefore, it can be seen that the magnetic flux density becomes uniform with the magnetic path to be written, and that magnetic saturation is prevented. According to the present embodiment, the torque is increased by 2 to 3% and the efficiency is improved by about 0.5% as compared with the permanent magnet embedded rotor in the first embodiment.

The present invention is not limited to the above-described embodiment, and various modifications can be made according to the present invention regardless of the number of poles, the shape of the permanent magnet burying hole, the shape of the permanent magnet, and the like. Yes, and they are not excluded from the scope of the present invention.

[0047]

As is apparent from the above description, according to the first aspect of the present invention, two layers of the punched holes for embedding permanent magnets in the same magnetic pole are present between the iron cores existing near the surface of the rotor core. Not only the magnetic path, but also the iron magnetic path existing between the vicinity of the rotor core surface of the punched holes for burying permanent magnets located on the inner peripheral side of the rotor of the adjacent magnetic pole can be effectively used, and the reluctance torque can be increased. can do.

According to the second aspect of the present invention, an effect of suppressing generation of invalid short-circuit magnetic flux on the end face of the permanent magnet located on the outer peripheral side of the rotor is provided.

According to the third aspect of the present invention, the magnetic pole surface area of the permanent magnet can be increased, the amount of magnetic flux by the permanent magnet can be increased, and the magnetic path between the punched holes for the two-layer permanent magnet can be increased. Has an arc shape, so that local magnetic saturation can be prevented.

According to the fourth aspect of the present invention, a highly efficient motor is provided by effectively utilizing the magnetic flux of the permanent magnet.

According to the fifth aspect of the present invention, it is possible to provide a motor with high reluctance torque and high efficiency.

According to the sixth aspect of the present invention, the amount of magnetic flux can be increased by increasing the magnetic pole area of the permanent magnet.

According to the seventh aspect of the present invention, since the permanent magnet is inexpensive flat plate, a highly efficient motor can be manufactured at low cost.

According to the eighth aspect of the invention, the reluctance torque can be increased in the one-way motor.

According to the ninth aspect of the present invention, in a one-way rotating motor, an effect of suppressing generation of an invalid short-circuit magnetic flux at an end face of a permanent magnet located on the outer peripheral side of the rotor is provided.

According to the tenth aspect of the present invention, in the motor rotating in one direction, the magnetic pole surface area of the permanent magnet can be increased, the amount of magnetic flux by the permanent magnet can be increased, and punching for a two-layer permanent magnet can be performed. Since the magnetic path between the holes has an arc shape, local magnetic saturation can be prevented.

According to the eleventh aspect of the present invention, in the one-way motor, the magnetic flux of the permanent magnet is effectively used,
Provide a highly efficient motor.

According to the twelfth aspect of the present invention, in the one-way motor, the reluctance torque is increased,
A highly efficient motor can be provided.

According to the thirteenth aspect of the present invention, in the motor rotating in one direction, the amount of magnetic flux can be increased by increasing the magnetic pole area of the permanent magnet.

According to the fourteenth aspect of the present invention, in the one-way rotating motor, since the permanent magnet is inexpensive flat plate, a highly efficient motor can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a permanent magnet embedded rotor according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a distance from a rotor center to a circular arc center and a magnetic pole area;

FIG. 3 is a diagram showing a relationship between a distance from a rotor center to a circular arc center and a magnetic pole opening angle.

FIG. 4 is a magnetic flux diagram of the permanent magnet embedded rotor according to the first embodiment of the present invention.

FIG. 5 is a sectional view of a permanent magnet embedded rotor according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a permanent magnet embedded rotor according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a permanent magnet embedded rotor according to a fourth embodiment of the present invention.

FIG. 8 is a magnetic flux diagram of a permanent magnet embedded rotor according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view of a conventional permanent magnet embedded rotor.

FIG. 10 is a magnetic flux diagram of a conventional permanent magnet embedded rotor.

[Explanation of symbols]

 2 Shaft 3 Riveted pin 11 Rotor 12 Rotor core 13a, 13b Perforated hole for embedding permanent magnet 14a, 14b Permanent magnet 15b, 15c Magnetic path 16 Flat part

Claims (14)

[Claims] 1. A substantially cylindrical rotor core made of a high magnetic permeability material such as iron or laminated electromagnetic steel sheets, and having two layers of perforated holes for burying permanent magnets in the axial direction in the radial direction per pole, In the permanent magnet embedded rotor in which one or more permanent magnets are embedded in each of the permanent magnet embedded holes, both ends of the permanent magnet embedded holes extend to near the rotor core surface, and two layers of the same magnetic pole are formed. The magnetic path width of the iron present between the punched holes for embedding permanent magnets near the rotor core surface exists between the punched holes for embedding permanent magnets located on the rotor inner peripheral side of the adjacent magnetic poles and near the rotor core surface. A permanent magnet embedded rotor that is almost the same as the magnetic path width of iron. 2. The magnetic pole area of a permanent magnet embedded in a punched hole for embedding permanent magnets located on the inner peripheral side of the rotor is equal to the magnetic pole area of a permanent magnet embedded in a punched hole for embedding permanent magnets located on the outer peripheral side of the rotor. 2. The permanent magnet embedded rotor according to claim 1, which is larger. 3. The permanent magnet embedded rotor according to claim 1, wherein the punched holes for embedding permanent magnets have an arc shape that is convex on the inner peripheral side of the rotor. 4. The permanent magnet embedded rotor according to claim 3, wherein the rotor has a circular arc shape having a gap large enough to allow the permanent magnet to be inserted into the punched hole for embedding the permanent magnet. 5. A perforated hole for burying a permanent magnet so that a magnetic path width of iron existing between adjacent holes near the rotor core of a perforated hole for burying a permanent magnet located on the inner peripheral side of the rotor of the adjacent magnetic pole is constant. 4. The rotor with embedded permanent magnets according to claim 3, wherein a flat portion is provided near an outer end of the arc. 6. When the number P of rotor magnetic poles is 4 or more and the outer diameter of the rotor is r, the arc center of the punched hole for embedding the permanent magnet is 0.85 r / cos (180 / cm) from the center of the rotor.
6. The permanent magnet embedded rotor according to claim 5, wherein the rotor is located at a position of 0.7 r / cos (180 / P) or less. 7. The permanent magnet embedded rotor according to claim 1, wherein one or more plate-shaped permanent magnets are embedded in the punched holes for embedding permanent magnets. 8. A substantially cylindrical rotor core made of a material having high magnetic permeability such as iron or laminated electromagnetic steel sheets, and having two layers of punched holes for burying permanent magnets in a radial direction per pole in the axial direction, In the permanent magnet embedded rotor in which one or more permanent magnets are embedded in each of the permanent magnet embedded holes, both ends of the permanent magnet embedded holes extend to near the rotor core surface, and two layers of the same magnetic pole are formed. Of the iron magnetic path widths existing between the punched holes for embedding permanent magnets near the rotor core surface, the rotor rotation advance side is Xf, the rotor rotation reverse side is Xb, and the magnetic pole width is located on the rotor inner peripheral side of the adjacent magnetic pole. Xf> X, where Xc is the magnetic path width of the iron existing between the punched holes for embedding the permanent magnet and near the rotor core surface.
A permanent magnet embedded rotor in which c> Xb. 9. The magnetic pole area of a permanent magnet embedded in a punched hole for embedding permanent magnets located on the inner peripheral side of the rotor is equal to the magnetic pole area of a permanent magnet embedded in a punched hole for embedding permanent magnets located on the outer peripheral side of the rotor. The permanent magnet embedded rotor according to claim 8, which is larger. 10. The rotor with embedded permanent magnets according to claim 8, wherein the punched holes for embedding permanent magnets have an arc shape that is convex on the inner peripheral side of the rotor. 11. A permanent magnet embedded rotor according to claim 10, wherein the permanent magnet has a circular arc shape having a gap large enough to allow the permanent magnet to be inserted into the permanent magnet embedded hole. 12. A punched hole for burying a permanent magnet so that a magnetic path width of iron existing between adjacent holes near the rotor core surface of the punched hole for burying a permanent magnet located on the inner peripheral side of the rotor is constant. The permanent magnet embedded rotor according to claim 10, wherein a flat portion is provided near an outer end of the circular arc. 13. When the number P of rotor magnetic poles is 4 or more and the outer diameter of the rotor is r, the arc center of the punched hole for embedding the permanent magnet is 0.85 r / cos (180) from the center of the rotor.
13. The permanent magnet embedded rotor according to claim 12, wherein the rotor is located at a position of 0.7 r / cos (180 / P) or less. 14. The permanent magnet embedded rotor according to claim 7, wherein one or more plate-shaped permanent magnets are embedded in the punched holes for embedding permanent magnets.