JP2007306735A - Permanent magnet motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet motor which can achieve high responsiveness equivalent to a surface magnet synchronous motor, and high torque not less than that of an embedded permanent magnet synchronous motor, using semihard magnetic material. <P>SOLUTION: The permanent magnet motor has a stator 3 and a rotor 4 opposed via a diametrical air gap to the stator 3, and has a permanent magnet in the rotor main body 41 of the rotor 4. The main body 41 of the rotor is constituted by stacking two or more sheets of roughly circular semihard magnetic plate material 411 in its axial direction, and a rare earth magnet 43 is provided inside. Moreover, the semihard magnetic plate material 411 has a nonconductive film or a nonconductive combined layer by surface processing on each lamination face to be stacked. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a permanent magnet motor having a permanent magnet in a rotor.

Examples of conventional permanent magnet motors include a surface magnet synchronous motor and an embedded magnet synchronous motor (see, for example, Non-Patent Document 1).
FIG. 12 is a view showing an example of a conventional permanent magnet motor showing a rotor structure of a surface magnet synchronous motor and an embedded magnet synchronous motor, which is shown in Non-Patent Document 1, Tables 1 and 1. .
In FIG. 12, the surface magnet synchronous motor has a structure in which a permanent magnet is provided on the outer peripheral surface of the rotor, and the magnetic permeability of the permanent magnet is almost equal to the magnetic permeability in vacuum, so that the magnetic resistance with respect to the armature winding is large. Is as described in Non-Patent Document 1. Therefore, since the inductance of the armature winding is small and the responsiveness is good, the surface magnet synchronous motor is most often used mainly for the servo motor.
On the other hand, since the embedded magnet synchronous motor can use reluctance torque in addition to magnet torque, as described in Non-Patent Document 1, it is possible to increase the torque.
FIG. 13 is a view showing an example of the shape of a magnetic steel sheet constituting a rotor of a conventional embedded magnet synchronous motor, and is shown in FIG.
In FIG. 13, the magnetic steel sheet 5 is provided with a magnet hole 6 that forms a V shape with two holes for each magnetic pole. A plurality of the electromagnetic steel plates 5 are laminated, and permanent magnets (not shown) are inserted into the magnet holes 6 to form the magnetic poles of the rotor 7.
Thus, the permanent magnet motor which has a permanent magnet in the conventional rotor uses the permanent magnet on the outer periphery or the inside of the rotor core according to the use.
By the way, although it is unrelated to two synchronous motors demonstrated above, there exists a semi-hard magnetic material as a conventionally known material (for example, refer nonpatent literature 2).
FIGS. 14 and 15 are examples of hysteresis characteristics of semi-hard magnetic materials that are conventionally known, and are shown in FIGS. 7 and 2 and FIGS. 7 and 6 of Non-Patent Document 2. FIG.
According to the characteristics of the material shown in FIG. 14, the residual magnetic flux density is less than 1.9 T, and the coercive force is about 3.2 kA / m. Further, according to the characteristics of the material shown in FIG. 15B, the residual magnetic flux density is less than 1.5 T, and the coercive force is about 4 kA / m. These values can be said to be a permanent magnet that is very easy to demagnetize, although it has a higher residual magnetic flux density than a rare-earth magnet often used in conventional permanent magnet motors. Alternatively, the semi-hard magnetic material has the characteristics of a weak permanent magnet compared to a rare earth magnet that is a strong permanent magnet.
FIGS. 16 to 18 are examples of metal materials classified into conventionally known semi-hard magnetic materials and their magnetic properties. Tables 7 and 1, Tables 7 and 2 and Table 7 of Non-Patent Document 2 are shown.・ It is shown in 4.
As shown in these figures, metal materials classified as semi-hard magnetic materials have various magnetic properties, but in terms of international units, the residual magnetic flux density is 1.2 T or more and the coercive force is 1 kA / m or more. There are many things.
Yoji Takeda, Nobuyuki Matsui, Shigeo Morimoto, Yukio Honda “Design and Control of Embedded Magnet Synchronous Motor”, published by Ohm Co., Ltd., pages 4-8 Iwama Yoshiro, "Magnetic Engineering Course 3, Hard Magnetic Materials" Maruzen Co., Ltd., pp. 193-205 Japanese Patent Laying-Open No. 2005-57958 (FIG. 1)

A conventional surface magnet synchronous motor, which is a conventional permanent magnet motor, has a structure in which a permanent magnet is provided on the outer peripheral surface of a rotor. Therefore, the gap magnetic flux density is directly limited to the magnetic characteristics of the permanent magnet, and the increase in torque is caused by the magnetism of the permanent magnet. There was a problem that it was difficult without improvement of characteristics.
In addition, an embedded magnet synchronous motor, which is a conventional permanent magnet motor, cannot reductance torque in order to obtain reluctance torque, and abrupt changes in current are limited. There was a problem that it was difficult to seek.
The present invention has been made to solve such problems. A permanent magnet that uses a semi-hard magnetic material and has a high responsiveness comparable to that of a surface magnet synchronous motor and a higher torque than that of an embedded magnet synchronous motor. The object is to provide a motor.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 is a permanent magnet motor having a stator and a rotor facing the stator through a radial gap, and having a permanent magnet in a rotor body of the rotor. The rotor body is formed by laminating a plurality of semi-rigid magnetic plates in the axial direction, and a rare earth magnet is provided inside.
The invention described in claim 2 is characterized in that the rotor body is formed by stacking substantially circular semi-rigid magnetic plates.
The invention according to claim 3 is characterized in that the semi-rigid magnetic plate has a non-conductive compound layer or a non-conductive compound layer by surface treatment on each laminated surface to be laminated.
The invention according to claim 4 is characterized in that the rotor body has a shaft hole at the center and a magnet hole for inserting a plurality of rare earth magnets outside thereof.
The invention according to claim 5 is that the rare earth magnet is plate-shaped and magnetized in the thickness direction, and the sum of the areas of the magnetic pole surfaces that provide magnetic flux to one magnetic pole of the rotor of the rare earth magnet is It is characterized by exceeding the area of one magnetic pole on the outer peripheral surface of the rotor.

According to the first aspect of the present invention, the rotor main body is composed of a laminate of semi-hard magnetic plates that are weak permanent magnets, and the semi-hard magnetic plate near the surface of the rotor main body is in a region where magnetization is substantially saturated. Because it is used, it becomes the same state as that using a permanent magnet on the surface, high responsiveness equivalent to that of a surface magnet synchronous motor is obtained, and a rare earth magnet, which is a strong permanent magnet provided inside, magnetizes the semi-rigid magnetic plate material. In order to further reinforce, it is possible to provide a permanent magnet motor that can achieve higher torque than an embedded magnet synchronous motor.
Further, according to the invention described in claim 2, since the laminated body is formed by laminating substantially circular semi-rigid magnetic plates in the axial direction, the laminated body is rotated by a method similar to that of a conventional embedded magnet synchronous motor. A permanent magnet motor which can manufacture a child and does not require an increase in manufacturing cost by a new construction method can be provided.
According to the invention described in claim 3, the semi-rigid magnetic plate material has a non-conductive compound layer formed by a non-conductive film or surface treatment on each laminated surface to be laminated. A permanent magnet motor with low eddy current loss can be provided because the semi-rigid magnetic plates are non-conductive.
Further, according to the invention of claim 4, the laminate has a hole that fits into the shaft in the center and a hole that inserts a plurality of rare earth magnets outside thereof, so that it is easy to hold the rare earth magnet, A rotor of a permanent magnet motor that can be easily fixed to a shaft can be provided.
According to the invention described in claim 5, since the sum of the areas of the magnetic pole faces that provide magnetic flux to one magnetic pole of the rotor of the rare earth magnet exceeds the area of one magnetic pole of the outer peripheral face of the rotor, The magnetic flux of the rare earth magnet concentrates on the outer peripheral surface of the rotor, and by obtaining a gap magnetic flux density that is higher than the magnetic flux density of the rare earth magnet, higher torque than that of the conventional surface magnet synchronous motor is achieved. It is possible to provide a permanent magnet motor capable of achieving the above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing a permanent magnet motor in a first embodiment of the present invention. FIG. 2 is a perspective view for explaining the structure of the rotor body and the rare earth magnet in FIG.
1 and 2, a permanent magnet motor 1 has a frame 2, a stator 3 fixed to the inner surface of the frame 2, and a rotor 4 that is rotatably arranged inside the stator 3. is doing. The stator 3 includes a stator core 31 and a stator winding 32 wound around the stator core 31.
The rotor 4 is arranged so as to be substantially V-shaped inside the rotor body 41 and outside the shaft 42 inside the rotor body 41, the shaft 42 connected to the rotor body 41, and the rotor 42. The rare earth magnet 43 is provided.
The rotor body 41 is configured by laminating a plurality of semi-rigid magnetic plates 411 having a substantially circular shape in which the distribution of magnetic flux in the gap is appropriately adjusted. The semi-rigid magnetic plate material 411 has a shaft hole 412 in the center and a long magnet hole 413 in the radial direction for inserting a plurality of rare earth magnets 43 on the outside thereof. The magnet hole 413 is formed in a substantially V shape with one hole. After the semi-rigid magnetic plate material 411 is laminated in the axial direction to form the rotor body 41, the rare earth magnet 43 is inserted and fixed in the magnet hole 412, and the shaft 42 is fitted into the shaft hole 412. Are fixed.
Moreover, the semi-hard magnetic plate material 411 has a non-conductive film on each laminated surface, and the laminated semi-hard magnetic plate materials are made non-conductive to reduce eddy current loss.
The rare earth magnet 43 to be inserted and fixed in the magnet hole 413 of the rotor body 41 is plate-shaped, and is magnetized in the thickness direction, and provides magnetic flux to one magnetic pole of the rotor body 41 of the rare earth magnet 43. The sum of the areas of the two magnetic pole surfaces 431 and 432 is designed to be about 1.8 times the area of one magnetic pole of the outer peripheral surface 414 of the rotor body 41. Therefore, each magnetic pole of the rotor 4 having, for example, 10 poles of the present embodiment has a magnetic flux density of the rare earth magnet 43 concentrated on the outer peripheral surface 414 of the rotor main body 41 and a gap magnetic flux density higher than the magnetic flux density of the rare earth magnet 43. Thus, not only the conventional surface magnet synchronous motor but also the torque higher than that of the conventional embedded magnet synchronous motor can be achieved.

FIG. 3 is an image diagram of magnetic flux in an unloaded state constituting the magnetic pole of the rotor in the first embodiment, and shows a state where the magnetic flux of the rare earth magnet is concentrated on the outer peripheral surface of the rotor body.
In FIG. 3, a rotor body 41 configured by laminating a plurality of semi-rigid magnetic plates 411 has a substantially V-shaped magnet hole 413 for each magnetic pole, and is plate-shaped and has a plate thickness direction. Two rare earth magnets 43 magnetized are inserted. For this reason, the surface of the rotor main body 41 with the S pole facing the inside of the V shape is the S pole, and the surface of the rotor main body 41 with the N pole facing the inside of the V shape is the N pole. The sum of the areas of the two magnetic pole surfaces 431 and 432 that provide magnetic flux to one magnetic pole of the rotor 4 of the rare earth magnet 43 is approximately 1.8 times the area of one magnetic pole on the outer peripheral surface of the rotor 4. Therefore, the magnetic flux of the rare earth magnet 43 is concentrated on the outer peripheral surface of the rotor 4 and is shown in FIG. 15 (b), “tempered at 650 ° C. after cold rolling and further 650 after cold rolling. In the present embodiment using the semi-hard magnetic plate material tempered at 0 ° C., a gap magnetic flux density of 1.5 T or more is obtained at the maximum position.
Hereinafter, differences in design and characteristics between a conventional embedded magnet synchronous motor and a permanent magnet motor according to an embodiment of the present invention will be described using a rotor having the same shape as that of the present embodiment.

FIG. 4 is a graph showing hysteresis characteristics of a general electromagnetic steel sheet. As a material characteristic of the electrical steel sheet, it has been developed to reduce the coercive force in order to reduce hysteresis loss. In addition, the residual magnetic flux density with respect to the saturation magnetic flux density is often smaller than that of the semi-hard magnetic material.
Assuming an embedded magnet synchronous motor, when the rotor body 41 of the semi-rigid magnetic plate 411 of the rotor 4 shown in FIG. 3 is replaced with the rotor body of the electromagnetic steel plate having the characteristics shown in FIG. The operating point on the hysteresis characteristics of the electrical steel sheet representing the vicinity of the surface of the magnetic pole of the child body is a point (Hd, Bd). In this case, the largest magnetoresistive part with respect to the magnetomotive force of the rare earth magnet 43 is the gap between the stator 3 and the rotor 4, and the electromagnetic steel sheet has an operating point on a region where the hysteresis characteristic magnetization is not saturated. . Further, the operating point under the armature reaction at the maximum load is subjected to a demagnetizing field of ΔH and becomes a point (Hs, Bs). Since the inductance of the stator winding is greatly influenced by the amount of change ΔB in the magnetic flux density with respect to the demagnetizing field ΔH of the stator winding, the inductance becomes a large value in such a relatively large design of ΔB / ΔH. . Since an embedded magnet synchronous motor that uses reluctance torque does not set the operating point in the region where the magnetization of the hysteresis characteristic of the magnetic steel sheet is almost saturated, the inductance of the stator winding is generally a large value, which is a response as a servo motor. It becomes a bad motor.

On the other hand, FIG. 5 shows the hysteresis characteristics of the semi-rigid magnetic plate material 411 used in this example. The operating point on the hysteresis characteristic of the magnetized semi-hard magnetic plate 411 representing the vicinity of the surface of the magnetic pole of the rotor body 41 shown in FIG. 3 is a point (Hd, Bd). In this case, the largest magnetoresistive portion with respect to the magnetomotive force of the rare earth magnet 43 is the semi-hard magnetic plate 411, and has an operating point on a region in which the magnetization in the first quadrant of the hysteresis characteristic is substantially saturated. Further, the operating point under the armature reaction at the maximum load is subjected to a demagnetizing field of ΔH and becomes a point (Hs, Bs).
The difference in design between the conventional embedded magnet synchronous motor and the permanent magnet motor of the embodiment of the present invention is that the operating point on the hysteresis characteristic of the electromagnetic steel sheet used in the embedded magnet synchronous motor is in the first quadrant. The operating point on the hysteresis characteristic of the semi-rigid magnetic plate material used in the present example is that the magnetization spanning from the first quadrant to the second quadrant is in a substantially saturated region in all operating states of the motor. Therefore, the amount of change ΔB in the magnetic flux density with respect to the demagnetizing field ΔH of the stator winding is reduced as in the conventional surface magnet synchronous motor, and the torque linearity against the armature reaction is improved and the inductance of the stator winding is also reduced. It is as small as a surface magnet synchronous motor.
Further, the design is different from that of the embedded magnet synchronous motor in that the reluctance torque is not used.

FIG. 6 shows an image diagram of the magnetic flux under the armature reaction of the rotor of the embedded magnet synchronous motor using a general electromagnetic steel plate. However, the image diagram of the magnetic flux in the no-load state is described as being the same as FIG.
In FIG. 6, under the armature reaction, a magnetic field acts to weaken the magnetic flux of the rotor 4 or to distort it in the circumferential direction. Since the magnetic steel sheet 415 is not in a state in which magnetization is substantially saturated and is flexible with respect to changes in magnetic flux, its distribution state is easily changed. Further, since the magnetic resistance of the magnetic circuit including the stator 3 is increased with respect to the magnetomotive force of the rare earth magnet 43, the leakage magnetic flux on the outer peripheral side of the rare earth magnet 43 is increased and the operating point of the magnetic flux density is greatly reduced. This is as shown in FIG. Therefore, the linearity of torque is poor and the maximum torque is also small.

On the other hand, FIG. 7 shows an image diagram of magnetic flux under the armature reaction of the rotor of the permanent magnet motor in the first embodiment of the present invention.
In FIG. 7, even if a magnetic field that distorts the magnetic flux of the rotor 4 in the circumferential direction acts under the armature reaction, the semi-rigid magnetic plate 411 is in a state of substantially saturated magnetization and is in a magnet state, Changes are unlikely to occur and the distribution is difficult to change. The decrease in the operating point of the magnetic flux density is small as shown in FIG. Therefore, the linearity of the torque is good and the maximum torque is large.
There are many types of metal materials classified as semi-hard magnetic materials as shown in FIGS. 16 to 18, but the semi-hard magnetic material 411 in the present invention has a residual magnetic flux density of 1.2 T or more and a coercive force of 1 kA. It is intended between / m and 10 kA / m. By using these materials, the operating point as shown in FIG. 5 can be designed. Many of these materials have strengths higher than those of electromagnetic steel plates, and are advantageous in terms of anti-centrifugal force even when the motor is operated at high speed.

As a result of the above, FIG. 8 shows the difference in characteristics between a conventional embedded magnet synchronous motor having the same shape rotor and the permanent magnet motor of the embodiment of the present invention.
FIG. 8 is a graph comparing torque T characteristics with respect to load current I of a conventional embedded magnet synchronous motor and a permanent magnet motor of the present invention. In the small load current range, the gap magnetic flux density of the embedded magnet synchronous motor having a small magnetic resistance relative to the magnetomotive force of the rare earth magnet is higher. Therefore, the magnitude of the torque for the same load current is higher in the embedded magnet synchronous motor. Excellent. However, when the load current increases, the permanent magnet motor of the embodiment of the present invention having excellent torque linearity reverses, and the maximum torque Tph also exceeds the maximum torque Tpi of the embedded magnet synchronous motor.

FIG. 9 shows hysteresis characteristics of a rare earth magnet on the outer peripheral surface of a general conventional surface magnet synchronous motor.
In FIG. 9, the rare earth magnet has an operating point (Hd, Bd) on the region where the magnetization of the demagnetization curve in the second quadrant of the hysteresis characteristic is substantially saturated, and operates under the armature reaction at the maximum load. The point receives a demagnetizing field of ΔH and becomes a point (Hs, Bs). In all operating states of the motor, the operating point is in a region where the magnetization is substantially saturated, so that the change amount ΔB of the magnetic flux density is small and the inductance of the stator winding is also small.

As a result of the above, FIG. 10 shows a difference in characteristics between the conventional surface magnet synchronous motor having the rotor of the same size and the permanent magnet motor of the embodiment of the present invention.
FIG. 10 is a characteristic comparison of torque T with respect to load current I of a conventional surface magnet synchronous motor and a permanent magnet motor of an embodiment of the present invention. In the permanent magnet motor according to the embodiment of the present invention, the magnetic flux of the rare earth magnet is concentrated on the outer peripheral surface of the rotor, and a gap magnetic flux density of 1.5 T or more is obtained at the maximum position. Compared with the magnet synchronous motor, the magnitude of the torque for the same load current is excellent in each stage, and the maximum torque Tph is also superior to the maximum torque Tps of the surface magnet synchronous motor.

  The present invention differs from conventional permanent magnet motors such as embedded magnet synchronous motors and surface magnet synchronous motors in that a half permanent magnet is used instead of a single permanent magnet on the outer periphery or inside of the rotor core. This is a portion in which a rare earth magnet, which is a strong permanent magnet, is inserted into a hard magnetic material to constitute a rotor.

FIG. 11 is a front sectional view of a rotor of a permanent magnet motor showing a second embodiment of the present invention.
In FIG. 11, the rotor 4A has a rotor main body 41A, a shaft 42A connected to the rotor main body 41A, and a rare earth magnet 43A disposed inside the rotor main body 41A and outside the shaft 42A. is doing.
The rotor body 41A is configured by laminating a plurality of semi-rigid magnetic plates 411A having a circular shape. The semi-rigid magnetic plate material 411A has a shaft hole 413A at the center, and has magnet holes 412A into which a plurality of rare earth magnets 43A are inserted radially so as to partition the magnetic poles with respect to each magnetic pole, And it has the hollow hole 416 used as the cavity provided between each magnet hole 412A. The hollow hole 416 has a triangular shape whose bottom is the shaft side. The triangular shape is an isosceles triangle that is long in the radial direction, and each corner is formed in an arc shape.
The semi-rigid magnetic plate material 411A having such a configuration is formed by laminating a plurality of sheets in the axial direction to constitute the rotor main body 41A, and then inserting and fixing the rare earth magnet 43A in the magnet hole 412A, and the shaft in the shaft hole 413A. 42A is fitted and fixed.
Moreover, the semi-hard magnetic plate material 411A has a non-conductive film on each laminated surface, and the laminated semi-hard magnetic plate materials 411A are made non-conductive to reduce eddy current loss.
The rotor main body 41A has one magnet hole 412A which is long in the radial direction so as to partition the magnetic pole with respect to each magnetic pole, and is one plate of the rare earth magnet magnetized in the plate thickness direction. 43A is inserted. Therefore, the surface of the rotor body 41A where the rare earth magnets 43A on both sides of a certain magnetic pole face the south pole is the south pole, and the surface of the rotor body 41A where the north pole faces the north pole is the north pole. The sum of the areas of the two magnetic pole faces that provide magnetic flux to one magnetic pole of the rotor body 41A of the rare earth magnet 43A is designed to be about 1.8 times the area of one magnetic pole on the outer peripheral face of the rotor. is doing. Therefore, each magnetic pole of the rotor 4 having, for example, 10 poles in this embodiment has a magnetic flux density of the rare earth magnet 43A concentrated on the outer peripheral surface 414A of the rotor main body 41A, and has a gap magnetic flux density higher than the magnetic flux density of the rare earth magnet 43A. Thus, not only the conventional surface magnet synchronous motor but also the torque higher than that of the conventional embedded magnet synchronous motor can be achieved.
Further, the hollow hole 415 of the rotor main body 41A prevents the magnetic flux of the rare earth magnet 43A from becoming a leakage magnetic flux toward the shaft side.
In this embodiment, since the number of rare earth magnets 43A is small with respect to the number of magnetic poles, the configuration in the rotor 4 can be simplified. Other features of the motor of this embodiment that are not described are the same as those of the first embodiment.
This embodiment is different from the first embodiment in that each magnetic pole is not provided with a substantially V-shaped magnet hole 412, but a single magnet hole 412 A that is long in the radial direction is provided so as to partition the magnetic pole. It is the point which inserted and comprised the rotor 4A.

  The permanent magnet motor of the present invention has been described above, but when this structure is used as a rotor of a synchronous generator, a generator that can withstand downsizing and high loads can be provided.

It is a front sectional view showing a permanent magnet motor in the first example of the present invention. It is a perspective view explaining the structure of the rotor main body and rare earth magnet in FIG. It is an image figure of the magnetic flux in the no-load state which comprises the magnetic pole of the rotor in 1st Example of this invention. It is a graph which shows the hysteresis characteristic of a general electromagnetic steel plate. It is a graph which shows the hysteresis characteristic of the semi-hard magnetic board | plate material used in 1st Example of this invention. It is an image figure of the magnetic flux under the armature reaction of the rotor of the conventional embedded magnet synchronous motor. It is an image figure of the magnetic flux under the armature reaction of the rotor in 1st Example of this invention. It is the graph which compared the characteristic of the torque T with respect to the load current I of the conventional embedded magnet synchronous motor and the permanent magnet motor of this invention. It is a graph which shows the hysteresis characteristic of the rare earth magnet of the outer peripheral surface of the conventional surface magnet synchronous motor. It is the graph which compared the characteristic of the torque T with respect to the load current I of the conventional surface magnet synchronous motor and the permanent magnet motor of the Example of this invention. It is a front sectional view of a rotor of a permanent magnet motor showing a second embodiment of the present invention. It is a figure which shows the example of the conventional permanent magnet motor which shows the rotor structure of a surface magnet synchronous motor and an embedded magnet synchronous motor (nonpatent literature 1, Table 1-1). It is a figure which shows the example of a shape of the electromagnetic steel plate which comprises the rotor of the conventional embedded magnet synchronous motor (patent document 1, FIG. 1). It is a graph which shows the example of the hysteresis characteristic of the semi-hard magnetic material known conventionally (nonpatent literature 2, FIG. 7 * 2). It is a graph which shows the example of the hysteresis characteristic of the semi-hard magnetic material known conventionally (nonpatent literature 2, FIG. 7 * 6). Examples of metal materials classified into conventionally known semi-hard magnetic materials and their magnetic properties are shown (Non-Patent Document 2, Tables 7 and 1). Examples of metal materials classified into conventionally known semi-hard magnetic materials and their magnetic properties are shown (Non-Patent Document 2, Tables 7 and 2). Examples of metal materials classified into conventionally known semi-hard magnetic materials and their magnetic properties are shown (Non-Patent Document 2, Tables 7 and 4).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Permanent magnet motor 2 Frame 3 Stator 31 Stator iron core 32 Stator winding 4, 4A Rotor 41, 41A Rotor main body 411, 411A Semi-hard magnetic plate material 412, 412A Shaft hole 413, 413A Magnet hole 414, 414A Outer circumference Surface 415 Magnetic steel plate 416 Hollow hole 42, 42A Shaft 43, 43A Rare earth magnet 431, 432 Magnetic pole surface 5 Magnetic steel plate 6 Magnet hole 7 Rotor

Claims (5)

In a permanent magnet motor having a stator and a rotor facing the stator via a radial gap, and having a permanent magnet in a rotor body of the rotor,
A permanent magnet motor, wherein the rotor body is configured by laminating a plurality of semi-rigid magnetic plates in the axial direction, and a rare earth magnet is provided therein.   The permanent magnet motor according to claim 1, wherein the rotor body is configured by stacking substantially circular semi-rigid magnetic plates.   3. The permanent magnet motor according to claim 1, wherein the semi-rigid magnetic plate has a non-conductive film or a non-conductive compound layer formed by surface treatment on each laminated surface to be laminated.   The permanent magnet motor according to claim 1, wherein the rotor body has a shaft hole in the center and a magnet hole into which a plurality of rare earth magnets are inserted outside.   The rare earth magnet is plate-shaped and magnetized in the thickness direction, and the sum of the areas of the magnetic pole faces that provide magnetic flux to one magnetic pole of the rotor of the rare earth magnet is equal to one magnetic pole of the outer peripheral face of the rotor. The permanent magnet motor according to claim 1, wherein the permanent magnet motor exceeds an area of the permanent magnet motor.

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