JPH08256441A - Permanent magnet rotor - Google Patents

Abstract

PURPOSE: To efficiently utilize the amount of magnetic flux generated from a permanent magnet by arranging one of permanent magnets in the radial- direction of a rotor, arranging the other permanent magnet at a specific angle for the radial direction of the rotor, and specifying the ratio of the number of magnetic poles to the number of permanent magnets. CONSTITUTION: In a permanent magnet rotor 10 where permanent magnets 1a and 1b are buried between an outer cylinder 21 and an inner cylinder 22 consisting of a soft magnetism metal, one magnetic pole of the rotor 10 is formed by two permanent magnets 1a and 1b. Then, one of the permanent magnets 1a and 1b is arranged in radial direction of the rotor 10 and the other is arranged at a specific angle of θ (0<θ<90 degrees) for the radial direction of the rotor 10, and further the ratio of the number of magnetic poles to the number of permanent magnets 1a and 1b is set to 1:1.5. In the rotor 10, the ratio of inner-diameter dimension to outer-diameter dimension is set to 1:1.2-4.0, thus efficiently utilizing the amount of magnetic flux generated from the permanent magnets 1a and 1b in the case of a thin thickness of the rotor 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a so-called internal magnet type permanent magnet rotor used in a brushless DC motor, a generator or the like.

[0002]

2. Description of the Related Art In recent years, brushless DC servo motors, AC servo motors, etc., which combine a high energy product rare earth permanent magnet material such as Sm-Co system or Nd-Fe-B system and a control method using a semiconductor, have been widely used. It is put to practical use.
Particularly in relation to environmental problems, the development of electric vehicles and electric motorcycles has become active. A synchronous motor using a permanent magnet, which can be made smaller than an induction motor, is suitable as a motor used for these propulsion applications. The rotor of the synchronous motor is required to have (1) a high magnetic flux density on the surface of the rotor in order to realize miniaturization, and (2) the permanent magnet should not be demagnetized or destroyed due to a thermal cycle or high-speed rotation. To be done. In addition, the above-mentioned propulsion motor generally generates power called regenerative braking during deceleration. At this time, since a reverse magnetic field is applied to the permanent magnet, it is essential that the permanent magnet is not demagnetized.

Rotor structures used in motors using permanent magnets are roughly classified into the following two types. One is a type in which a permanent magnet is fixed to the outer peripheral portion of a soft magnetic metal rotor with an adhesive (hereinafter referred to as a surface magnet type rotor). FIG.
Shows an example of the surface magnet type rotor. In FIG. 4, 1 is a permanent magnet, 2 is a rotor base made of soft magnetic metal,
Eight permanent magnets 1 are usually adhered to the outer peripheral surface of the rotor base 2 with an adhesive to form an eight-pole surface magnet type rotor.
The other type is a type in which permanent magnets are radially embedded inside the rotor and a magnetic flux is taken out to the outer peripheral portion of the rotor mainly by utilizing homopolar repulsion of the permanent magnets (hereinafter referred to as an internal magnet type rotor). FIG. 5 shows an example of the internal magnet type rotor (Japanese Patent Publication No. 63-41307 discloses a radial magnet embedded type). In FIG. 5, the permanent magnets 1 on both ends of the rotor base 2 forming one arbitrary magnetic pole on the outer peripheral surface of the rotor are
This is a so-called homopolar repulsion type structure in which the same magnetic poles face each other. In order to form a total of 8 poles on the outer peripheral surface of the rotor, FIG.
Uses one permanent magnet.

[0004]

The conventional surface magnet type rotor has the following problems. One is that the permanent magnet is separated from the rotor and the rotor is broken due to the thermal stress caused by the difference in the thermal expansion coefficient between the permanent magnet and the rotor base and the centrifugal force generated by the rotation of the rotor. For example, when a high output of several tens of kW is required as in a motor for an electric vehicle, both the diameter of the rotor and the maximum number of revolutions increase, which results in an increase in centrifugal force and the above-mentioned separation is more likely to occur. Further, the eddy current generated on the surface of the rotor due to the AC magnetic flux of the stator increases as the rotation speed increases, and thus the amount of heat generated by the rotor further increases. in this way,
The surface magnet type rotor has a problem that the rotor is apt to break due to an increase in centrifugal force and heat generation.

Another problem is that in the surface magnet type rotor, when the rotor diameter and the rotor length are determined, the torque constant (the output is proportional to the product of the torque constant, the current and the rotational speed) is almost determined, which is high. There was a problem that it was difficult to improve performance. That is, since the magnet is in direct contact with the gap between the surface magnet type rotor and the stator, there is no magnetic leakage and the magnetic flux can be used effectively, but the magnet cross-sectional area is determined by the rotor outer diameter, and the gap magnetic flux density Is almost determined only by the magnet material properties. As described above, when the surface magnet type rotor is used, the torque constant is proportional to the product of the effective magnetic flux amount per rotor pole and the number of magnetic poles, but even if the number of poles is increased, the area per pole is increased. As a result, the effective magnetic flux amount per one pole decreases, so that an increase in the torque constant can hardly be expected.

On the other hand, in the internal magnet type rotor, if the number of magnetic poles is increased while keeping the rotor diameter, rotor length, and permanent magnet shape constant, the effective magnetic flux amount per pole hardly decreases, and the torque constant increases. From this, the internal magnet type rotor has a feature that it is possible to improve the performance by increasing the number of poles.

However, the conventional internal magnet type rotor has the following problems. First, since the permanent magnets are arranged radially, a short circuit of the magnetic flux occurs in the rotor inner peripheral portion, the magnetic flux generated by the permanent magnet does not concentrate on the rotor outer peripheral portion, and the magnetic flux is relatively small relative to the permanent magnet volume. The generation efficiency is poor. Therefore, there are not many practical examples. Another one
The other problem is that since the magnetic flux generation efficiency is poor, it is necessary to make the inner diameter small, the inertia moment of the rotor is larger than that of the surface magnet type rotor, and the controllability is poor. Also,
As shown in FIG. 6, a method of incorporating the permanent magnet 1 into the rotor base 2 has been proposed. However, in this method, since the magnetic flux short-circuiting portions 21 and 22 formed on the inner and outer peripheral sides of the permanent magnet 1 are the same magnetic body, (1) a part of the magnetic flux does not go out of the magnetic body and is short-circuited. (2) If the widths W ₂₁ and W ₂₂ of the magnetic flux short-circuited portion are reduced to prevent the magnetic flux from being short-circuited, the mechanical strength of the rotor becomes weak and the rotor cannot withstand the centrifugal force.
There is a problem. FIG. 6 is an example in which the number of magnetic poles on the outer peripheral surface of the rotor and the number of permanent magnets used are 1: 1.

Therefore, as a permanent magnet type rotor which solves the above-mentioned problems of the surface magnet type and the internal magnet type, the rotor base is composed of an inner cylinder part and an outer cylinder part made of soft magnetic metal, and There is disclosed a permanent magnet rotor (Japanese Patent Laid-Open No. 6-38415) having four or more magnetic poles, in which a permanent magnet that is magnetically integrated is arranged between the inner tubular portion and the outer tubular portion. This rotor has, for example, a structure in which magnets are embedded in a V shape, and the ratio of the number of magnetic poles on the outer peripheral surface of the rotor to the number of permanent magnets is 1: 2. In the mold, the ratio of the number of magnetic poles on the outer peripheral surface of the rotor to the number of permanent magnets is 1: 1.). In addition,
In FIGS. 7 and 8, reference numerals 21 and 22 respectively denote an outer cylinder portion and an inner cylinder portion of the rotor base 2 made of soft magnetic metal. However, in the case of FIG. 7, although there is an advantage that simple magnets such as rod-shaped, block-shaped, and plate-shaped magnets can be used, the cross-sectional area of the magnets used cannot be effectively used. Moreover, the magnetic flux density of the gap between the rotor and the stator cannot be maximized. Furthermore, the ratio of the number of magnetic poles on the outer peripheral surface of the rotor to the number of permanent magnets is 1:
Therefore, it can be said that the ratio of use of expensive permanent magnets is high.
In the case of FIG. 8, the ratio of the number of magnetic poles on the outer peripheral surface of the rotor to the number of permanent magnets is 1: 1 and the number of magnets used is small, but since an L-shaped magnet is used, for example, in the L-shaped permanent magnet 1. In the magnet manufacturing process, the crystal grain orientation (magnetic anisotropy imparting) process in the thickness t direction in the L-shaped permanent magnet 1 for imparting desired magnetic properties, the machining process for dimensioning, cracks, etc. Extremely complicated magnet manufacturing means such as careful handling over the entire manufacturing process that does not occur is required. Furthermore, in FIG. 7, when the (inner diameter dimension) :( outer diameter dimension) of the permanent magnet rotor is 1: 1.2 to 4.0, that is, the thickness of the permanent magnet rotor that can be used as a magnetic circuit is small. When the cross-sectional area of the permanent magnet is limited, there is a problem that the surface and the gap magnetic flux density of this permanent magnet type rotor cannot be maintained at a predetermined level.

The present invention solves the above-mentioned problems existing in the prior art, and a simple shape permanent magnet can be used in a motor rotor and a generator rotor using permanent magnets.
Especially, (inner diameter): (outer diameter) of the rotor is 1: 1.2
For thin rotor thicknesses such as ~ 4.0,
An object of the present invention is to provide a low-cost, high-performance permanent magnet rotor that is capable of extremely efficiently utilizing the amount of magnetic flux generated from a permanent magnet and has excellent durability that the permanent magnet is not separated from the rotor.

[0010]

In order to achieve the above object, according to the present invention, an outer cylinder part and an inner cylinder part made of a soft magnetic metal and a permanent magnet between the outer cylinder part and the inner cylinder part are provided. A permanent magnet rotor having embedded magnets, wherein one magnetic pole of the rotor is formed by two permanent magnets, and one of the permanent magnets is arranged in the radial direction of the rotor, and At a predetermined angle Θ with respect to the radial direction of the rotor.
(0 <Θ <90 degrees) is provided, and a technical means is adopted in which the ratio of the number of magnetic poles to the number of permanent magnets is 1 pole: 1.5. In the permanent magnet rotor of the present invention, (inner diameter dimension): (outer diameter dimension) =
It is preferable that the ratio is 1: 1.2 to 4.0.

In the present invention, an adhesive, a sealant, a resin molding, a non-magnetic metal (for example, known Al or Al alloy, etc.) is used so that the permanent magnets embedded in the rotor base are tightly fixed when the rotor rotates. ) It is desirable to fix the permanent magnet to the rotor by using a known fixing means such as die casting. This treatment may be carried out at normal temperature, but preferably under heating and heating at a temperature at which the rotor member does not oxidize or does not cause a problem in rotor function even if it oxidizes (in addition to the atmosphere, an inert gas atmosphere such as Ar or N ₂ may be used if necessary. In this case, the residual residual compressive stress remains in the permanent magnet after this treatment, and the permanent magnet is less likely to break. Further, depending on the conditions, it is possible to employ a method of fixing the permanent magnet to the rotor only by the magnetic attraction force of the permanent magnet, without using the above-mentioned fixing means. This method has the advantage that the rotor can be easily assembled.

There are roughly three means for forming the rotor base into a shape having an inner cylinder portion and an outer cylinder portion. One is a method in which thin soft magnetic metals (for example, silicon steel plate or low carbon steel) punched by a press are laminated and fixed to a rotor shaft. The second is a method of casting a soft magnetic metal and processing it if necessary. The third method is a method in which soft magnetic metal powder is formed into a predetermined shape by a known means such as pressing or injection molding, and then sintered, and sizing press is performed if necessary. The rotor forming means described above can be appropriately selected in consideration of the required shape, magnetic characteristics, cost and the like.

In the present invention, one of the permanent magnet type rotors is used.
The magnetic pole is formed by two permanent magnets, one of the permanent magnets is arranged in the radial direction of the rotor, and the other one is arranged at a predetermined angle Θ (0
<Θ <90 degrees), and the ratio of the number of magnetic poles to the number of permanent magnets is 1 pole: 1.5. With this configuration, the total of two magnet width lengths (effective cross-sectional areas) forming one magnetic pole can be maximized as compared with the conventional surface magnet type and internal magnet type rotors. Also, the gap magnetic flux density is maximized, and high performance of the rotor can be realized.

The permanent magnet used in the present invention can be manufactured by a known manufacturing method (eg, powder metallurgy, plastic working (upsetting, extrusion, rolling, etc.), bonded magnet method, casting method, ultraquenching method, etc.). It can be manufactured. A general formula representing the basic composition of the permanent magnet is R-Fe-B system, R
-Co5 system, R2-Co17 system, R-Fe-N system (R is one or more kinds of rare earth elements including Y, and if necessary Co, Al, Nb, Ga, Fe, C
u, Zr, Ti, Hf, Ni, V, Si, Sn, Cr,
Mo, Zn, Pt, Bi, Ta, W, Sb, Ge, Mn
It is possible to contain one or more kinds of elements selected from the above, which are effective for magnetic properties. In addition, O, C, N, H, P,
It may contain one or more unavoidable impurity elements selected from S and the like. 1) or 2 or more kinds of known permanent magnet materials such as a rare earth magnet represented by), a ferrite magnet, an alnico magnet, and a Mn-Al-C magnet can be used. Further, it is mainly composed of powder particles made of one or more of the above-mentioned permanent magnet materials, and a known thermoplastic resin, thermosetting resin or rubber material, or one or more of them. The known permanent magnet material (preferably anisotropic magnet) may be used to form the permanent magnet of the present invention. Of the above, R-Fe-
The B-based permanent magnet has an oxidation-resistant coating layer (for example, Ni, Cu, Al, Zn, Cr, Ni-) on its surface to prevent oxidation.
A plating layer made of one or more of P, Ti, Sn, Pb, Pt, Ag, Au, etc., and formed by a known electroless or electroplating means can be adopted. In addition to this, for example, vacuum deposition (for example, there is a method of uniformly coating a known metal or resin having high oxidation resistance on the entire surface), ion sputtering, ion plating, IVD, E.
One or two or more of known coating layer forming means such as VD can be adopted. Alternatively, an epoxy resin or the like may be electrodeposited. Then, in the case of imparting more excellent oxidation resistance, a combination of the above-mentioned coating layer forming means, for example, Cu
Ni plating (layer thickness of several μm to several tens of μm) is coated on the plating (layer thickness of several μm to several tens of μm), and epoxy resin is further electrodeposited thereon (of several μm to several tens μm). Layer thickness)
It is preferable to adopt the configuration or the like. ) Is preferably formed. Of these, Nd-Fe-B based anisotropic sintered magnets and / or bonded magnets (preferably anisotropic magnets) are particularly preferable.

The soft magnetic metal usable in the present invention includes:
For example, Fe, Ni, Co and ferromagnetic metals containing these as the main components can be used. As an example of this, for example, pure iron,
Soft iron, and known ferromagnetic steel materials such as carbon steel, low alloy steel, structural special steel, tool steel, ferritic and martensitic stainless steels, and known ferromagnetic iron castings such as cast iron and cast steel And Fe-Ni-based alloys such as permalloy; and Fe-Ni-Co-based alloys such as Kovar; and silicon steel sheets and permendur. Furthermore, well-known soft ferrites such as Mn-Zn ferrite can be effectively utilized. And 1 type or 2 types or more of these can be used preferably in this invention.
Furthermore, among these, one or more kinds of low carbon steel, silicon steel sheet, permendur, pure iron and the like are particularly preferable.

[0016]

Since 1.5 permanent magnets are used for each magnetic pole, an inexpensive permanent magnet type rotor can be constructed. Moreover, as a result of efficiently utilizing the cross-sectional area of the embedded permanent magnet, the outer peripheral surface of the rotor and the gap magnetic flux density are maximized, and a high-performance permanent magnet rotor can be constructed. In particular, the ratio of (inner diameter dimension) to (outer diameter dimension) of the permanent magnet rotor is 1: 1.
It is extremely advantageous when it is 2 to 4.0 (the thickness of the permanent magnet type rotor functioning as a magnetic circuit is thin). Also,
Since a permanent magnet having a simple shape can be used, it is advantageous in terms of magnet manufacturing technology and cost.

[0017]

The present invention will be described below with reference to examples. FIG.
FIG. 3 is a cross-sectional view of essential parts of a permanent magnet rotor showing an embodiment of the present invention. In FIG. 1, 1a and 1b are block-shaped permanent magnets (Nd-Fe-B type anisotropic sintered magnets manufactured by Hitachi Metals Ltd., HS-37BH), respectively, for imparting oxidation resistance to the surface. It has a Ni-plated layer. Permanent magnets 1a (4 in total) are arranged along the radial direction of the permanent magnet rotor 10 and permanent magnets 1b (8 in total).
Is a predetermined angle Θ with respect to the radial direction of the permanent magnet rotor 10.
It is arranged so as to give (0 <Θ <90 degrees).
The permanent magnets 1a and 1b have magnetic anisotropy imparted by orienting crystal grains in the thickness t ₁ and t ₂ directions thereof,
After the predetermined magnetization, the N and S polarities shown in FIG. 1 are given. The permanent magnet 1a has a thickness t ₁ of 5 mm and a width W ₁ of 2
1 mm, the length l ₁ in the rotation axis direction (not shown) is 55 mm
Is. The dimensions of the permanent magnet 1b are 5 mm in thickness t ₂ and W ₂ in width.
Is 45 mm, and the length l ₂ in the rotation axis direction (not shown) is 55
mm. The permanent magnets 1a and 1b are respectively embedded in the rotor base 2 of the permanent magnet type rotor 10, and the outer cylinder portion 21 and the inner cylinder portion 22 are formed via the embedded permanent magnets to form the rotor base 2. There is. The rotor base 2 has an inner diameter of 90 mm, an outer diameter of 155 mm, and a length of 110 mm (not including the shaft member of FIG. 3 described later).
It is made of soft magnetic metal (JIS S15C). Therefore, (inner diameter dimension) of rotor 10: (outer diameter dimension) = 1:
It is 1.7. Then, the material for the rotor base 2 is subjected to cutting and wire electric discharge machining to form a total of twelve slots 30 for accommodating the permanent magnets 1a and 1b as shown in FIG. In order to connect and fix the shaft member 15 having the shaft 4 serving as the rotating shaft and the rotor 10 as shown in FIG. 8, eight M8 screw holes 16 are provided in the vicinity of the outer peripheral portion of the rotor base 2. Then, four permanent magnets 1a in which an adhesive (Araldite: AV-138) is applied to the permanent magnet insertion slot 30 (12 in total) are provided.
After burying 2 tiers and 1b in 8 tiers x 2 tiers, fix them,
A permanent magnet rotor 10 having the cross-sectional view of the main part shown in FIG. 1 was manufactured. In order to reduce the eddy current loss generated inside the rotor base body 2, the rotor base body 2 is made of a thin plate (thickness: 0.
It is preferable to stack (01 mm to several mm).

FIG. 3 is a perspective view showing an example of assembly of the rotor 10 according to the present invention. In FIG. 3, the rotor 10 has a cross-sectional view of the form shown in FIG. 1, and is made of stainless steel (for example, S
The permanent magnet type rotor of the present invention is assembled by fastening the shaft member 15 made of US304 or the like) and the rotor 10 incorporating the permanent magnets 1a and 1b with bolts (not shown). Instead of the shaft member 15, after the permanent magnets 1a and 1b are incorporated in the rotor base 2, a rotary shaft in which an adhesive (Araldite: AV-138) or the like is applied to the shaft insertion hole 3 formed in the rotor base 2 is used. Not shown shaft 40 (eg SUS
304) and the rotor base 2 and the shaft 40 are fixed to each other with an adhesive.

Next, after connecting the rotor 10 and the shaft member 15 of the present invention in FIG. 3 described above, a counter weight (not shown) is attached to obtain dynamic balance, and then a dedicated magnetizing yoke (shown in the figure). Built-in pulse magnetization (22kOe × 8m) at room temperature using
sec) was performed to apply a magnetic force to the permanent magnets 1a and 1b incorporated in the rotor 10.

FIG. 2 is an explanatory diagram related to the arrangement of two (two types) permanent magnets forming one magnetic pole of the rotor 10 of the present invention. In FIG. 2, point O is the center of rotation of the rotor, R is the outer radius of the rotor, r is the inner radius of the rotor, and Θ ₁ is the angle of formation of any one magnetic pole formed on the outer peripheral surface of the rotor: angle AOB.
One end of each of the solid line permanent magnet a and the permanent magnet b is located at a point P and a point Q near the outer peripheral surface of the rotor so as to form an angle Θ ₁ . The other end of the permanent magnet a and the permanent magnet b is located at an arbitrary position between the points A and B near the inner peripheral surface of the rotor, for example, the point C, and forms an angle BOC = Θ ₂ . . In addition, the permanent magnet a and the permanent magnet b
Have a predetermined length (not shown) in the rotation axis direction of the rotor 10. Then, the permanent magnet a and the permanent magnet b
When the width length of each is W ₁ and W ₂ , respectively, the total of the permanent magnet width lengths (W ₁ + W ₂ ) is maximum when Θ ₂ = 0 or Θ ₁ . That is, when either the permanent magnet a or the permanent magnet b is located in the radial direction in FIG. 2 (that is, the arrangement configuration of the permanent magnets 1a and 1b shown by the dotted line), (W ₁ + W ₂ ) is the maximum width. As a result, the total effective cross-sectional area of the permanent magnets a and b that can effectively contribute as a magnetic flux source generated on the outer peripheral surface side of the rotor can be maximized.
The surface magnetic flux density and the jacket magnetic flux density of the rotor can be maximized.

A rotor 10 of the present invention (first embodiment) having a cross-sectional view of a main part of FIG. 1 and a conventional rotor having the same inner diameter dimension and outer diameter dimension as the rotor of the first embodiment (FIGS. 4 and 5). Comparative Examples 1 to 3) each corresponding to the cross-sectional view of the main part of FIG. 7 were manufactured, and the stator was arranged with a gap of 0.5 mm. Table 1 shows the results of measuring the surface magnetic flux density and the jacket magnetic flux density of each rotor.

[0022]

[Table 1]

The rotor of the present invention is superior in surface magnetic flux density and gap magnetic flux density as compared with Comparative Examples 1 to 3.
In Comparative Example 2, the permanent magnets 1 are arranged along the radial direction as shown in FIG. 5, but as described above, the ratio of (inner diameter dimension) to (outer diameter dimension) of the rotor is 1: 1. Since it is as small as 7, the surface magnetic flux density and the gap magnetic flux density are extremely small.

Next, in the above-described rotor 10 (embodiment 1) of the present invention, the change in the surface magnetic flux density of the rotor with respect to the (outer diameter / inner diameter) dimension ratio when the outer diameter dimension is changed with respect to the inner diameter dimension. FIG. 9 shows (a). In addition, in each of the rotors of Comparative Examples 1 to 3 described above, the rotor has the same dimension as (a) and the outer diameter is changed with respect to the inner diameter of the rotor with respect to the (outer diameter / inner diameter) dimension ratio. Change in surface magnetic flux density: based on Comparative Example 1 (b), based on Comparative Example 2 (c), and based on Comparative Example 3 (d) are also shown in FIG.

From FIG. 9, (outer diameter / inner diameter) = 1.2 to 4.
In the range of 0, the example (a) is the comparative example (b),
It has a high surface magnetic flux density and is superior to (C) and (D). In (a), (b), (c), and (d),
When the stators were arranged with a gap of 0.5 mm between them and the gap magnetic flux density was measured, the same measured value as the surface magnetic flux density in FIG. 9 was obtained. In addition, in FIG. 9, (outer diameter /
It was found that in the region of (inner diameter)> 4, the surface magnetic flux densities of Example (a) and Comparative Example (d) were almost the same, and the superiority of the rotor of the present invention gradually disappeared.

Next, the durability spin test of Example 1 and Comparative Examples 1 to 3 at 80 ° C. for 1000 hours was conducted to examine the presence or absence of peeling (Table 2). In Table 2, ◯ means no abnormality, x means magnet peeling from the rotor, and-means that the test was not performed.

[0027]

[Table 2]

As shown in Table 2, the rotor of the present invention (Example 1) is less susceptible to peeling at high speed rotation at 80 ° C. than the surface magnet type (Comparative Example 1), and the conventional internal magnet type rotor ( It can be seen that it has durability against peeling equivalent to Comparative Examples 2 and 3).

In the embodiment of the present invention (FIG. 1), the rotor 10 has eight permanent magnets with 12 permanent magnets, and the permanent magnets 1b are arranged line-symmetrically with respect to the permanent magnets 1a.
Although the case where eight magnetic poles N and S poles on the outer peripheral surface of the rotor 10 are formed at equal intervals has been shown, the present invention is not limited to this, and the arrangement angles Θ of the permanent magnets 1b on both sides with respect to the permanent magnet 1a are individually set. May be arranged to give different angles Θ (0 <Θ <90 degrees).
The magnetic pole pattern on the outer peripheral surface can be made asymmetric. Further, for example, when this asymmetric magnetic pole pattern is applied, the rotor 1
The outer diameter of the rotor 10 and //
Alternatively, the substantially cylindrical rotor 10 (for example, the rotor 10) whose inner diameter is partially changed within the configuration range of the present invention
The outer peripheral surface and / or the inner peripheral surface of the rotor has a shape of the rotor 10 having one or more concave portions or convex portions over the entire axial length thereof. ) Is good. Further, the number of magnetic poles of the rotor of the present invention is not limited as long as it satisfies the configuration of the present invention, but it is preferably used for 4 to 100 poles having a particularly high practicality.

[0030]

According to the present invention, in a rotor for a motor and a rotor for a generator using a permanent magnet, a simple permanent magnet can be used, and 1.5 permanent magnets can be used for one magnetic pole of the rotor. In particular, when the rotor thickness is thin, that is, the ratio of the inner diameter dimension to the outer diameter dimension of the rotor is 1: 1.2 to 4.0, the amount of magnetic flux generated from the permanent magnet can be efficiently used, and the permanent magnet is less likely to be separated from the rotor. It is possible to provide a high-performance and inexpensive permanent magnet rotor having excellent durability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of a rotor of the present invention.

FIG. 2 is a diagram illustrating the width of a permanent magnet forming one magnetic pole in the rotor of the present invention.

FIG. 3 is a diagram showing an example of assembly of the rotor of the present invention.

FIG. 4 is a diagram showing a cross-sectional view of a main part of a conventional rotor.

FIG. 5 is a diagram showing a cross-sectional view of a main part of a conventional rotor.

FIG. 6 is a diagram showing a cross-sectional view of a main part of a conventional rotor.

FIG. 7 is a diagram showing a cross-sectional view of a main part of a conventional rotor.

FIG. 8 is a diagram showing a cross-sectional view of a main part of a conventional rotor.

FIG. 9 is a diagram showing a change in surface magnetic flux density with respect to a (outer diameter / inner diameter) dimensional ratio of a rotor.

[Explanation of symbols]

1a permanent magnet, 1b permanent magnet, 2 rotor base, 3
Shaft insertion hole, 4 shaft, 10 rotor, 15
Shaft member, 16 screw holes, 21 outer cylinder part, 22
Inner cylinder, 30 slots, 40 shaft.

Claims (2)

[Claims] 1. A permanent magnet type rotor comprising an outer cylinder part and an inner cylinder part made of soft magnetic metal, and a permanent magnet embedded between the outer cylinder part and the inner cylinder part. One magnetic pole is formed by two permanent magnets, one of the permanent magnets is arranged in the radial direction of the rotor, and the other one is arranged at a predetermined angle Θ (0 <Θ <90 degrees), and the ratio between the number of magnetic poles and the number of permanent magnets is 1
Pole: A permanent magnet rotor characterized by having 1.5 poles. 2. In the rotor, (inner diameter):
The permanent magnet rotor according to claim 1, wherein (outer diameter dimension) = 1: 1.2 to 4.0.