JP5582383B2 - Embedded magnet rotor - Google Patents

Description

  The present invention relates to a motor for driving a hybrid vehicle, an elevator, a processing machine, etc., and a generator such as a wind-hydraulic power generator, as well as a magnet embedded rotor used for many rotating machines.

  As shown in FIG. 8, the most common configuration of a conventional magnet-embedded rotor is a magnet hole 102 formed in a rotor core 101 made of a laminate of electromagnetic steel plates constituting the rotor every 90 ° in the circumferential direction. There is known a magnet embedded rotor 100 in which a permanent magnet 103 magnetized in the thickness direction is inserted and arranged. In this magnet-embedded rotor 100, four poles that are alternately different in the circumferential direction are formed on the outer peripheral surface of the rotor core 101 as shown in the figure.

Various configurations other than those shown in FIG. 8 have been proposed for the magnet-embedded rotor in accordance with the number of magnetic poles formed on the outer peripheral surface of the rotor core, the formation position of the magnet hole, and the like. A configuration in which 6-pole and 8-pole magnetic poles are formed on the outer peripheral surface of the rotor core is shown.
As shown in FIG. 9, the rotor core 11 11 having the magnet holes 112 formed every 60 ° in the circumferential direction and the pair of magnet holes 122a and 122b formed every 45 ° in the circumferential direction as shown in FIG. Of the rotor core 121 formed with the V-shaped magnet hole 122 is inserted and arranged in the magnet holes 112 and 122 respectively in the thickness direction, and the former is the outer peripheral surface of the rotor core 111. The latter is an embedded magnet rotor that forms an 8-pole magnetic pole on the outer peripheral surface of the rotor core 121.

  In the magnet-embedded rotor having any of the above-described configurations, the permanent magnet inserted and arranged in the magnet hole is magnetized before being inserted and arranged in the magnet hole, and then inserted (so-called magnetized assembly method), or nothing. A magnetized permanent magnet is magnetized (magnetized) by one of the methods (so-called assembling magnetizing method) in which magnetized permanent magnets are inserted into the magnet holes and then magnetized together with the rotor core.

A magnet embedded rotor constituting a relatively small rotating machine inevitably reduces the outer diameter of the rotor core and restricts the size of the permanent magnet to be used. Even if the method of magnetizing after the permanent magnet is inserted and arranged (the latter method) is selected, the permanent magnet is sufficiently magnetized to generate a desired magnetic flux from the magnetic pole formed on the surface of the rotor core. .
In consideration of handling of permanent magnets after magnetization and automation of the manufacturing process, a method of magnetizing after permanent magnets are inserted into magnet holes formed in the rotor core is generally adopted. Yes.

On the other hand, the magnet embedded rotor constituting a relatively large rotating machine inevitably increases the outer diameter of the rotor core and the size of the permanent magnet to be used. There is a concern that sufficient magnetization cannot be achieved.
In recent years, in a wind power generator exceeding a power generation output of 1 MW, which has been attracting attention from the viewpoint of reducing global warming gas, both the diameter and the axial length of the rotor core are 1 m or more.
In addition, since permanent magnets inserted into the magnet holes are often Nd-Fe-B sintered magnets having excellent magnetic properties, the magnetizing coil not only increases in size but also forms a magnetizing magnetic field. For this reason, the current flowing through the magnetizing coil is extremely large, the power source for generating the magnetizing magnetic field is enlarged, and the assembly magnetizing method is not suitable for production on an industrial scale.

  In a magnet embedded rotor of a rotating machine used for a large generator for wind power generation or the like, the dimensions of the permanent magnet itself are very large, and from the viewpoints of manufacturability, mechanical strength, etc., a plurality of pre-magnetized magnets are used. A method is adopted in which a magnet structure in which block-shaped permanent magnets are bonded and fixed in order while being laminated on a flat magnetic yoke is inserted into a magnet hole formed in the rotor core.

The rotor core uses a laminated body of electromagnetic steel sheets as a countermeasure against eddy currents.
The electromagnetic steel sheet is formed into a predetermined shape by punching, but it is difficult to obtain a high dimensional accuracy compared with general machining, and the size and position of the magnet hole formed in each electromagnetic steel sheet vary. Occur. Also, sufficient dimensional accuracy inside the magnet hole is not always obtained due to the deviation in the laminating direction of each electromagnetic steel sheet in the laminating process. As a result, irregularities occur on the wall surface of the finally obtained magnet hole.
When a permanent magnet is inserted and arranged in a non-magnetized state, even if there are irregularities on the wall surface of the magnet hole, an attractive force (magnetic attraction) is generated between the permanent magnet and the wall surface of the magnet hole. Therefore, even if the permanent magnet and the wall surface of the magnet hole come into contact with each other, the impact received by the permanent magnet is small, and the presence of the unevenness has little influence on the permanent magnet.

However, when a pre-magnetized permanent magnet is inserted and arranged in the magnet hole, the influence on the permanent magnet due to the presence of irregularities present on the wall surface of the magnet hole becomes large. That is, a magnetic attraction force is generated between the permanent magnet and the wall surface of the magnet hole, and the attraction force increases as the permanent magnet is inserted into the magnet hole. A shock will be applied. This impact often damages the permanent magnet and may cause damage. In the rotor embedded in a wind power generator with a rotor core having a diameter of 1 m or more, the magnetic attraction force is very strong, and the work of inserting and arranging the permanent magnet into the magnet hole becomes very complicated. .
Further, when the magnetized permanent magnet is broken inside the magnet hole of the rotor core, it is extremely difficult to remove the broken permanent magnet from the magnet hole and reuse the rotor core.

In an embedded magnet rotor using a rotor core with a large diameter, in addition to the problems caused by the magnetizing method and magnetic attraction force accompanying the increase in the size of the permanent magnet as described above, the size itself is a factor. There are the following problems.
That is, the centrifugal force that acts on a rotor having a large diameter, such as a magnet-embedded rotor for wind power generators, is extremely larger than the centrifugal force that acts on a rotor that has been frequently used in the past and has a small diameter. Therefore, in order to prevent the permanent magnet from jumping out of the rotating rotor core, the mechanical strength is prioritized over the magnetic efficiency, and the structure in which the permanent magnet is arranged inside the rotor core must be adopted. It is the present condition that we do not get.

Patent Document 2 proposes a rotating machine (motor) using a magnet-embedded rotor that solves the problems caused by the centrifugal force, has a simple structure, and is easy to manufacture. The main feature of the magnet-embedded rotor 130 described in Patent Document 2 is that it does not use a conventional rotor core made of a laminated body of electromagnetic steel sheets in which magnet holes are previously formed. As shown in FIG. 11, a configuration in which the permanent magnet 133 is directly attached to the rotating shaft 131 via the attachment member 132 is employed. At the time of attachment, the protruding concave portions 135 formed on both sides of the lower portion of the concave portion 134 provided on the rotating shaft 131 and the protruding convex portions 136 formed on both sides of the mounting member 132 are fitted together with the permanent magnet 133. The mounting member 132 is inserted and disposed in the rotation shaft recess 134.
It is described that when the magnet-embedded rotor rotates, the attachment member 132 can be prevented from coming off due to centrifugal force by the engagement of the protruding concave portion 135 and the protruding convex portion 136.
Although there is no specific description about the magnetization (magnetization) method of the permanent magnet 133, the final magnetization direction is assumed to be the thickness direction of the permanent magnet 133 as shown in the figure.

JP 2008-236890 A JP 2008-154329 A

However, in the configuration of Patent Document 2, the mounting member 132 itself forms a part of the outer peripheral surface of the rotor, so that the protruding recesses prevent the mounting member 132 and the permanent magnet 133 from coming off due to the centrifugal force. In order to achieve this by engaging 135 and the protruding convex portion 136, it is necessary to sufficiently increase the thickness of the protruding concave portion 135 and the protruding convex portion 136 from the viewpoint of securing mechanical strength. As a result, the distance between the permanent magnet 133 and the outer peripheral surface of the rotor core 130 (the rotor core thin wall portion where the permanent magnet 133 and the outer peripheral surface of the rotor core 130 are closest to each other) is increased. Magnetic loss due to the formation of a closed magnetic path as shown in the figure increases.
Therefore, even if the configuration of Patent Document 2 is adopted in a magnet embedded rotor having a rotor core with a large diameter, it is not much different from a conventionally known structure that prioritizes mechanical strength over magnetic efficiency. It is hard to say that the configuration satisfies the above requirements.

  Further, in the configuration of Patent Document 2, when the mounting member 132 to which the permanent magnet 133 previously magnetized (magnetized) in the thickness direction is inserted and disposed in the recess 134 of the rotating shaft 131, the permanent magnet 133 and the rotating shaft 131 are arranged. It is difficult to avoid the influence of the magnetic attractive force generated between the permanent magnet 133 and the permanent magnet 133 cannot be prevented from being damaged or damaged due to direct contact between the permanent magnet 133 and the surface of the concave portion 134.

The object of the present invention is to solve the above-mentioned problems of the prior art, and in particular, to insert a permanent magnet into a magnet hole formed in a rotor core having a relatively large diameter, such as a magnet-embedded rotor for wind power generation. An object of the present invention is to provide a magnet-embedded rotor that is effective in configuration.
In other words, by devising a holding structure in the magnet hole of a previously magnetized (magnetized) permanent magnet, even if the distance between the permanent magnet and the outer peripheral surface of the rotor core is narrow (thinner wall thickness is reduced) The permanent magnet can be prevented from jumping out of the rotor core due to the force, and the increase in the magnetic loss due to the closed magnetic circuit formation (short-circuiting of the magnetic flux generated from the permanent magnet) caused by the increase in the distance can be suppressed. The purpose is to provide a magnet-embedded rotor that can effectively use the potential possessed.
It is another object of the present invention to provide a magnet-embedded rotor that facilitates the insertion and arrangement of pre-magnetized permanent magnets into the magnet holes and can prevent the permanent magnets from being damaged or broken.

  In order to solve the above problems, the inventor has conducted intensive studies, and as a result, in a magnet-embedded rotor, a magnetic structure in which a holding structure of a magnet hole of a previously magnetized permanent magnet is integrally joined to the permanent magnet. As the present invention was completed, it was found that the object could be achieved by fitting the fitting part of the predetermined shape formed on the body yoke with the fitting part of the predetermined shape formed on the magnet hole. is there.

That is, in the magnet-embedded rotor according to the present invention, as described in claim 1, permanent magnets are inserted and arranged in magnet holes formed in the rotor core, and magnetic poles are formed on the outer peripheral surface of the rotor core. A magnet-embedded rotor, wherein a magnetic yoke is integrally joined to a main surface opposite to the main surface of the permanent magnet opposite to the outer peripheral surface of the rotor core, and the magnetic yoke A magnetic yoke fitting portion having a concave shape or a convex shape is formed on the surface opposite to the permanent magnet bonding surface, and the convex shape or the concave shape is formed at a position corresponding to the magnetic yoke fitting portion of the magnet hole. A magnet-embedded rotor, in which a magnet hole fitting portion is formed, the magnetic yoke fitting portion and the magnet hole fitting portion are fitted, and the permanent magnet is fixed to the magnet hole. .
By adopting the above configuration, the mechanical strength can be increased by moving the means for preventing the permanent magnet from jumping out of the rotor core due to centrifugal force substantially inside (center side) of the rotor core compared to the conventional configuration. It can be secured relatively easily, and the permanent magnet can be disposed closer to the outer peripheral surface of the rotor core than in the conventional configuration, and it is possible to provide a magnet-embedded rotor with excellent magnetic efficiency.
Further, by fitting the magnetic yoke fitting portion and the magnet hole fitting portion, it is possible to realize a safe and relatively easy permanent magnet even when a pre-magnetized permanent magnet is inserted into the magnet hole. The collision caused by the magnetic attractive force generated between the magnet and the wall surface of the magnet hole is reduced, and the permanent magnet can be prevented from being scratched or broken.

Further, in the magnet-embedded rotor according to the second aspect of the present invention, the magnetic yoke fitting portion has a dovetail shape, and the magnet hole fitting portion has a dovetail shape. The magnet-embedded rotor according to claim 1.
According to this configuration, a desired fitting can be achieved with the simplest structure.

In the magnet-embedded rotor according to the third aspect of the present invention, the magnetic yoke fitting portion and the magnet hole fitting portion are formed in a plurality of rows in the axial direction of the rotor core. The magnet-embedded rotor according to claim 1 or 2.
According to this structure, the centrifugal force which acts on a fitting part can be disperse | distributed effectively by selecting the number of rows with the shape of a fitting part.

4. The embedded magnet rotor according to claim 1, wherein the permanent magnet according to claim 4 is a bonded magnet obtained by bonding and integrating a plurality of block-shaped permanent magnets. .
According to this configuration, it is particularly effective when the permanent magnet is increased in size, and the mechanical strength is ensured by sequentially joining and arranging block-shaped permanent magnets preliminarily magnetized on the upper surface of the magnetic yoke. The size can be increased, and handling becomes easy.

5. The magnet-embedded rotor according to claim 1, wherein an outer diameter of the rotor core according to claim 5 is 1000 mm or more.
When the present invention is applied to such a magnet-embedded rotor having a large outer diameter, the effect can be most effectively utilized.

According to the present invention, a large centrifugal force of a large (large diameter) rotor can be held not on the outer peripheral surface of the rotor core but on the inside of the magnetic yoke located inside (center side) of the rotor core. Therefore, the thickness on the outer peripheral surface side of the permanent magnet in the rotor core can be reduced, and as a result, the magnetic flux generated by the permanent magnet can be effectively utilized and the magnetic efficiency can be improved.
In addition, even when a pre-magnetized permanent magnet is inserted and placed in the magnet hole, collision due to the magnetic attractive force between the permanent magnet and the wall surface of the magnet hole is reduced, and the permanent magnet can be prevented from being scratched or damaged. It becomes.

It is a fragmentary longitudinal cross-sectional view of the magnet embedded rotor of the present invention. FIG. 2 is a side view showing an arrangement relationship between a permanent magnet and a magnetic yoke in the magnet-embedded rotor of FIG. 1. FIG. 7 is a side view showing the positional relationship between permanent magnets and magnetic yokes according to another embodiment in the magnet-embedded rotor of FIG. 1. It is a fragmentary longitudinal cross-sectional view of the magnet embedded type rotor which consists of other embodiment of this invention. It is a longitudinal cross-sectional view of the magnet embedded rotor which consists of other embodiment of this invention. It is the elements on larger scale of FIG. It is a longitudinal cross-sectional view of the magnet embedded rotor which consists of other embodiment of this invention. It is a longitudinal cross-sectional view of the conventional magnet-embedded rotor. It is the schematic of the rotor core used for the magnet embedding type | mold rotor which consists of another conventional form. It is the schematic of the rotor core used for the magnet embedding type | mold rotor which consists of another conventional form. It is a longitudinal cross-sectional view of the magnet embedded type rotor which consists of another conventional form.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a partial longitudinal sectional view of a magnet-embedded rotor 10 of the present invention. FIG. 2 is a side view showing the positional relationship between the permanent magnet and the magnetic yoke in the magnet-embedded rotor of FIG.
In the figure, reference numeral 1 denotes a rotor core, which is composed of a laminated body of electromagnetic steel plates, and has a magnet hole 2 formed at a predetermined position. Reference numeral 3 denotes a permanent magnet obtained by joining and integrating a plurality of block-shaped permanent magnets magnetized in the thickness direction. The magnetic yoke 4 is provided on the main surface opposite to the main surface facing the outer peripheral surface of the rotor core 1. Are integrally joined. The magnetic yoke 4 has a flat plate-like portion 5 to be joined to the permanent magnet 3 and a magnetic yoke fitting portion 6 having a dovetail-like convex portion formed on the surface opposite to the joining surface of the permanent magnet 3. It consists of. In the configuration shown in the drawing, the axial lengths of the flat plate portion 5 and the magnetic yoke fitting portion 6 are the same, and the magnetic yoke fitting portion 6 not only acts on centrifugal force but also improves mechanical rigidity. A function as a guide at the time of insertion into the magnet hole 2 is provided.
Reference numeral 7 denotes a magnet hole fitting portion comprising a dovetail-like concave portion extending in the axial direction substantially at the center of the bottom surface of the magnet hole 2, and is fitted with the magnetic yoke fitting portion 6.
The size of the magnet hole 2 is such that a so-called magnet structure in which the permanent magnet 3 and the magnetic yoke 4 are integrated can be inserted and arranged, and an adhesive or a buffer is provided between the magnet structure and the wall surface of the magnet hole. It is preferable that the size is such that a clearance capable of arranging the material can be formed. In the drawing, the clearance is exaggerated, but the clearance on the main surface side of the permanent magnet 3 facing the outer peripheral surface of the rotor core 1 also becomes a magnetic gap. It is not preferable from the viewpoint of efficiency, and it is preferable to select an optimum clearance according to the processing accuracy of each component member.
The magnet structure in which the permanent magnet 3 and the magnetic yoke 4 are integrated is inserted and arranged in the magnet hole 2 by fitting the magnetic yoke fitting portion 6 and the magnet hole fitting portion 7. The magnet-embedded rotor is configured.
In such a configuration, a magnetic pole is formed at a predetermined position (in the figure, an N pole is formed) on the outer peripheral surface of the magnet-embedded rotor 10 of the present invention by the magnetic flux generated from the permanent magnet 3.

In a general embedded magnet rotor that has been frequently used, the wall surface of the magnet hole formed in the rotor core receives the centrifugal force (the wall surface on the outer peripheral surface side of the rotor core as viewed from the magnet structure side). However, in the case of the magnet-embedded rotor 10 according to the present invention, the rotor 10 is received at two places of the magnet hole 2 and the fitting portion including the magnetic yoke fitting portion 6 and the magnet hole fitting portion 7. ing.
Therefore, the centrifugal force applied to the magnet structure is distributed and received, and the centrifugal force received by the wall surface of the magnet hole 2 is finally transmitted (between the permanent magnet 3 and the outer peripheral surface of the rotor core). Such stress is reduced, there is no need to increase the strength of this portion, and the position of the magnet structure can be arranged closer to the outer peripheral surface of the rotor core.
Therefore, according to the magnet-embedded rotor 10 of the present invention, the rotor core thin portion 8 where the permanent magnet 3 and the outer peripheral surface of the rotor core 1 are closest can be made narrower (thinner) than in the conventional configuration. The magnetic loss due to the closed magnetic path formed through the rotor core thin portion 8 can be reduced, and the magnetic flux can be efficiently generated in the magnetic pole portion.

  When the magnet structure formed by the pre-magnetized permanent magnet 3 and the magnetic yoke 4 shown in FIG. 2 is inserted into the magnet hole 2 of the rotor core 1, the magnet structure is the magnet hole 2. Although attracted to the wall surface (in particular, the outer peripheral side wall surface of the rotor core), the magnetic yoke fitting portion 6 constituting the magnet structure is fitted with the magnet hole fitting portion 7, so that the magnet structure As a result, a force acts in a direction opposite to the attracting direction, and as a result, the permanent magnet 3 and the wall surface of the magnet hole 2 do not come into contact with each other, and the magnet structure is inserted and disposed at a predetermined position of the magnet hole 2. Even if contact is made, the frictional force accompanying the insertion is reduced, and the problem of scratches and breakage on the surface of the permanent magnet 3 is greatly reduced. Even if irregularities peculiar to the electromagnetic steel sheet laminate exist on the wall surface of the magnet hole 2, the influence is very small.

  In FIG. 1 and FIG. 2, the magnetic yoke fitting portion 6 has been described as having a dovetail-like convex portion having the same axial length as the magnetic flat plate portion 5. According to the centrifugal force acting on the magnet structure, as shown in FIG. 3, the dovetail-like convex portions are provided only at both axial end portions of the magnetic plate-like portion 5. Can be achieved.

Further, the shape of the magnetic yoke fitting portion 6 is not limited to the dovetail-like convex portion, and for example, an inverted T-shaped shape as shown in FIG. 4 can be selected. . In other words, any shape can be selected as long as it can exert a force against the centrifugal force acting on the magnet structure, and the concave portion of the magnet hole fitting portion formed corresponding to the convex portion shape is processed. It can be appropriately selected in consideration of means and the like.
Furthermore, the magnetic yoke fitting portion 6 does not need to be formed integrally with the flat plate-like portion 5, and may be configured to be integrated using a bolt, an adhesive, or the like after being separately processed and created.

  1 and 4 show a configuration in which the magnetic yoke fitting portions 6 are provided in only one row in the axial direction, the number of rows is selected along with the shape of the fitting portion 6. Thereby, the centrifugal force which acts on the fitting part 6 can be disperse | distributed effectively.

  In the above description, the magnetic yoke 4 is formed with a convex fitting portion and the magnet hole 2 is formed with a concave fitting portion. Even if a concave fitting portion is formed in 4 and a convex fitting portion is formed in the magnet hole 2, the same effect can be obtained.

  In the configuration shown in FIG. 1 and FIG. 2, the length of the magnet structure has been described on the assumption that it has the same dimension as the axial length of the rotor core 1. The plurality of divided magnet structures may be sequentially inserted into the magnet holes 2 formed in the rotor core 1 to finally have the same length as the axial length of the rotor core 1. .

It has been described above that the permanent magnet 3 shown in FIG. 1 has a structure in which a plurality of block permanent magnets magnetized (magnetized) in the thickness direction are joined and integrated. Usually, from the viewpoint of the efficiency of the bonding work to the magnetic yoke 4, it is preferable to magnetize in advance after bonding to the magnetic yoke 4. However, it is not easy to magnetize the Nd—Fe—B sintered magnet having excellent magnetic properties together with the magnetic yoke 4. Further, the block-shaped permanent magnets are repelled from each other because the magnetic poles are adjacent to each other.
The inventor forms a small bonded magnet in which a plurality of block magnets are bonded and fixed to a size that can be magnetized, and after magnetizing at once in this state, the small bonded magnet is fixed with a specific jig. Move to the flat plate-like portion 5 of the magnetic yoke 4, and firmly bond and fix these small joined magnets and the magnetic yoke 4, and then sequentially add the other magnetized small joined magnets in the same manner as described above. By the method, it was bonded and fixed to the flat plate-like portion 5 of the magnetic yoke 4 to finally produce a magnet structure constituting the magnet-embedded rotor of the present invention.
A plurality of block-shaped magnets before magnetization are bonded and fixed in advance to the flat plate-like portion 5 of the magnetic yoke 4, and then a pair of magnetized yokes (not shown) that form a magnetic pole surface having a predetermined area with these integrated products. This magnetizing method is repeated a plurality of times while being partially magnetized with the block-shaped magnet interposed therebetween, thereby finally creating a magnet structure constituting the magnet-embedded rotor of the present invention. Also confirmed that it is possible.

As a material of each member constituting the magnet-embedded rotor of the present invention, a conventionally known material can be used.
For example, various known materials can be used as the permanent magnet, but it is most preferable to use a Nd—Fe—B based sintered magnet from the viewpoint of magnetic properties.
As the material of the rotor core, a laminate made of a soft magnetic material such as an electromagnetic steel sheet is preferable from the viewpoint of workability and eddy current countermeasures, but other laminates such as permalloy (an alloy mainly composed of FeNi) can also be used. In addition, it may be formed by cutting out from a block of soft magnetic material such as electromagnetic steel or dust core.
The magnetic yoke can also be made of a soft magnetic material such as a magnetic steel sheet, permalloy, a dust core, or soft iron.

FIG. 5 is a longitudinal sectional view showing another embodiment of the magnet-embedded rotor of the present invention.
The permanent magnet 3 magnetized in the thickness direction is inserted into each of the magnet holes 2a and 2b of the rotor core 1 in which the V-shaped magnet hole 2 composed of a pair of magnet holes 2a and 2b formed every 45 ° in the circumferential direction is inserted. This is a magnet-embedded rotor 30 that is arranged and forms 8-pole magnetic poles having different polarities alternately in the circumferential direction on the outer peripheral surface of the rotor core 1.
In addition, the said permanent magnet 3 consists of a dovetail-like convex part formed in the surface on the opposite side to the flat surface part 5 joined to the permanent magnet 3, and the joining surface of the permanent magnet 3 similarly to FIG. The magnetic yoke 4 comprising the magnetic yoke fitting portion 6 is fixed integrally.
Further, a magnet hole fitting portion 7 (not shown) is formed at a portion corresponding to the magnet yoke fitting portion 6 of the magnet hole 2 and is fitted to each other.
In addition, 9 is a through-hole for rotating shaft arrangement | positioning in the figure.

FIG. 6 is a partially enlarged view of FIG.
Centrifugal force indicated by a thick black arrow acts outward from the axis of the rotor core 1 to each magnet structure composed of the permanent magnet 3 and the magnetic yoke 4 by the rotation of the rotor 30. However, the force that causes the magnet structure due to the centrifugal force to jump out of the rotor core is not only the wall surface of the magnet hole 2 but also the fitting portion with the magnet yoke fitting portion 6 and the magnet hole fitting portion 7. Is suppressed (dispersed).
By the above action, the rotor core thin portion 8 where the permanent magnet 3 and the outer peripheral surface of the rotor core 1 are closest can be made very narrow (thin), and the closed magnetic circuit formed via the thin portion 8 (Indicated by bold solid lines in the figure)
It is possible to reduce the magnetic loss due to.
That is, the magnetic flux generated from the permanent magnet 3 is effectively applied to the magnetic poles formed on the surface of the rotor core 1, and as a result, the magnetic efficiency can be improved.

FIG. 7 is a longitudinal sectional view showing another embodiment of the magnet-embedded rotor of the present invention.
Permanent magnets 3 magnetized in the thickness direction are inserted and arranged in magnet holes 2 formed at intervals of 45 ° in the circumferential direction of the rotor core 1, and the polarity is alternately changed in the circumferential direction on the outer circumferential surface of the rotor core 1. This is a magnet-embedded rotor 40 that forms a magnetic pole.
The permanent magnet 3 is composed of a flat plate-like portion 5 to be joined to the permanent magnet 3 and two rows of dovetail-like convex portions 6 a and 6 b formed on the surface opposite to the joining surface of the permanent magnet 3. The magnetic yoke 4 comprising the magnetic yoke fitting portion 6 is fixed integrally.
Further, the magnet hole 2 corresponding to the magnetic yoke fitting portion 6 has a magnet hole formed of two rows of mortise-like recesses at positions corresponding to the dovetail-like convex portions 6a and 6b. The fitting part 7 (not shown) is formed and is mutually fitted.
In addition, 9 is a through-hole for rotating shaft arrangement | positioning in the figure.
In this configuration, since there are a plurality of fitting portions, centrifugal force is further dispersed, and the degree of freedom in designing the shape and dimensions of each fitting portion is improved.
Even in this configuration, the rotor core thin portion 8 where the permanent magnet 3 and the outer peripheral surface of the rotor core 1 are closest to each other can be made very narrow (thin), and the magnet embedding of the present invention described above can be performed. The magnetic efficiency can be improved in the same manner as the mold rotor.

  The magnet-embedded rotor of the present invention is not limited to the rotor core having the shape, number and arrangement of the magnet holes described above, but a so-called magnet in which permanent magnets are arranged in the magnet holes formed in the rotor core. Any embedded rotor can be used in any configuration.

As the magnet-embedded rotor of the present invention, magnet holes 2 formed at four locations every 90 ° in the circumferential direction of a rotor core 1 having an outer diameter (diameter) of 1000 mm × an axial length of 1000 mm made of a laminate of electromagnetic steel plates. Nd—Fe—B sintered magnet 3 (thickness (magnetization direction) 20 mm × width 400 mm × length 1000 mm, maximum energy product: 300 kJ / m ³ ) composed of a plurality of block permanent magnet bonded magnets The magnet-embedded rotor 10 having the arrangement shown in FIG. 1 was manufactured.
Using a rotor core and a permanent magnet having the same dimensions, a magnet-embedded rotor having the same configuration except for the fitting portion shown in FIG. 1 was manufactured as a comparative example.
Each of the embedded magnet rotors is designed to prevent the permanent magnet 3 from jumping out due to centrifugal force. When the permanent magnet 3 comes closest to the outer peripheral surface of the rotor core 1, the dimension (thickness) of the thin portion 8 and the rotor core When the amount of magnetic flux generated from the magnetic pole formed on the outer peripheral surface is compared, the embedded magnet type rotor 10 of the present invention has a thin portion 8 dimension of about 23 mm, which is about 12 mm, compared with the magnet embedded type rotor of the comparative example. It was confirmed that the amount of magnetic flux was improved by about 10%.

According to the present invention,
The centrifugal force generated in the permanent magnet by the rotation of the magnet-embedded rotor is formed not only on the wall surface of the magnet hole, but also on the magnetic yoke fitting part and magnet hole formed on the magnetic yoke that integrally bonds the permanent magnet. In order to disperse and receive by these fitting parts composed of the magnet hole fitting parts, it is possible to set a narrow interval between the permanent magnet and the outer peripheral surface of the rotor core, and as a result, to improve magnetic efficiency, This is effective not only for relatively small (small-diameter) embedded magnet rotors that are frequently used, but also for large-sized (large-diameter) embedded magnet rotors for wind power generators.

1, 101, 111, 121 Rotor core 2, 2a, 2b, 102, 112, 122, 122a, 122b Magnet holes 3, 103, 133 Permanent magnet 4 Magnetic yoke 5 Flat plate portions 6, 6a of magnetic yoke 6b Magnetic yoke fitting part 7 Magnet hole fitting part 8 Rotor core thin part (space between permanent magnet and rotor core outer peripheral surface)
9 Rotating shaft arrangement through-hole 10, 20, 30, 40, 100, 130 Embedded magnet rotor 135 Overhang recessed portion 136 Overhang convex portion A, B Closed magnetic path 134 Recessed shaft recess

Claims (5)

A magnet embedded rotor in which a permanent magnet is inserted and arranged in a magnet hole formed in the rotor core, and a magnetic pole is formed on the outer peripheral surface of the rotor core,
A magnetic yoke is integrally joined to the main surface of the permanent magnet opposite to the main surface facing the outer peripheral surface of the rotor core, and the magnetic yoke is opposite to the permanent magnet bonding surface. A magnetic yoke fitting portion having a concave or convex shape is formed on the surface, and a magnet hole fitting portion having a convex or concave shape is formed at a position corresponding to the magnetic yoke fitting portion in the magnet hole. The magnetic yoke fitting portion and the magnet hole fitting portion are fitted to fix the permanent magnet to the magnet hole, and the main surface of the permanent magnet facing the outer peripheral surface of the rotor core and the permanent magnet A magnet-embedded rotor having a clearance between magnet wall surfaces .




2. The magnet-embedded rotor according to claim 1, wherein the magnetic yoke fitting portion has a dovetail shape, and the magnet hole fitting portion has a dovetail shape. 3. 3. The magnet-embedded rotor according to claim 1, wherein the magnetic yoke fitting portion and the magnet hole fitting portion are formed in a plurality of rows in the axial direction of the rotor core.   The embedded magnet type rotor according to any one of claims 1 to 3, wherein the permanent magnet is a bonded magnet obtained by bonding and integrating a plurality of block-shaped permanent magnets. 5. The magnet-embedded rotor according to claim 1, wherein an outer diameter of the rotor core is 1000 mm or more.