JPH1032946A - Permanent magnet rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnetic rotor for generating a high magnetic density even if the number of poles is small in a permanent magnet rotor where a permanent magnet is buried inside. SOLUTION: Bolts 8, 8,... are fixed by units 9, 9... through through-holes 1b, 1b,..., 2b, 2b,... 3a, 3a,... so that rotary shafts 1 and 2 where edge plates 1a and 2a are integrally formed so as to sandwich both end faces of a rotor core 3. Also, four flat-plate-shaped permanent magnets is 4, 5, 6, and 7 are provided in the axial direction of the rotor core 3, the four permanent magnets are arranged so that a surface opposing an adjacent permanent magnetic has the same polarity and at the same time an angle formed by the adjacent permanent magnetic is at right angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet rotor used in a rotary motor, in which a permanent magnet is provided inside an iron core and a plurality of magnetic poles are formed on an outer peripheral surface of the iron core.

[0002]

2. Description of the Related Art Among rotors (hereinafter referred to as rotors) used in rotary motors and the like, a rotor using a permanent magnet can obtain a magnetic flux without the need for a field winding. Widely used for motors and the like. Among them, an embedded magnet rotor having a structure in which a permanent magnet is embedded inside an iron core (hereinafter, referred to as a permanent magnet rotor) can have a structure resistant to centrifugal force because the outer peripheral surface of the iron core is a rotor surface. It has the feature that the magnetic resistance of the air gap with the stator (hereinafter referred to as stator) can be reduced. However, when the number of poles is small, there is a disadvantage that it is difficult to obtain a high magnetic flux density structurally.

[0003]

3 and 4 show an example of the basic structure of a conventional permanent magnet rotor. Here, FIG.
(A) is a front view of the rotor core of the permanent magnet rotor, and FIG.
(B) shows a side view of the permanent magnet rotor. FIG. 4 is a perspective view showing the appearance of each component of the permanent magnet rotor shown in FIG. The permanent magnet rotors shown in these figures have four magnetic poles, and permanent magnets 21, 21,... Are inserted and arranged in four slots provided in the axial direction from the end face of the rotor core 20.

[0004] The rotor shaft 22 has permanent magnets 21, 21, 21.
A non-magnetic material is used to prevent the magnetic flux of... From being short-circuited through the shaft 22, and is provided through the shaft hole formed in the central axis of the rotor core 20 described above. Each of the permanent magnets 21, 21,... Is arranged so that the polarities of two adjacent permanent magnets are opposite to each other as shown in FIG. Four magnetic poles are formed on the outer peripheral surface of the rotor core.

[0005] End plates 23, 2 are provided on both end surfaces of the rotor core 20.
, And through holes 25, 25,..., And 26, 26, for passing bolts 24, 24,.
… Is drilled. The bolts 24, 24,... And nuts 27, 27,. The end plates 23 are also made of a non-magnetic material in order to prevent short-circuiting of the magnetic flux of the permanent magnets 21, 21,.

In the permanent magnet rotor having the above-described structure, the outer peripheral surface of the rotor core 20 serves as a magnetic pole surface as a rotor, and the magnetic flux generated from the permanent magnets 21, 21,.
It passes through the rotor core 20 and concentrates on the surface of the rotor. For this reason, each of the permanent magnets 21, 21,... With respect to the magnetic pole surface per one pole of the rotor core 20 (the surface facing the stator).
The ratio of the surface area (radial area of the rotor) may be increased. However, when the number of poles is small, for example, when the number of magnetic poles is two as in the case of the permanent magnet rotor shown in FIG. 5, the area of the permanent magnet 2 is made sufficiently large with respect to the surface area of the magnetic pole per pole. And the magnetic flux density of the rotor becomes a low value.

[0007] The present invention has been made in view of such circumstances, and in a permanent magnet rotor in which a permanent magnet is embedded, it is possible to increase the magnetic flux density of the rotor as compared with the related art. It is an object of the present invention to provide a permanent magnet rotor that can be used. Also, when the number of poles is small, the permanent magnet area can be made sufficiently large even when the number of poles is small, as compared with the conventional permanent magnet rotor where it was difficult to obtain a high magnetic flux density due to its structure. It is an object of the present invention to provide a permanent magnet rotor capable of increasing the magnetic flux density.

[0008]

According to a first aspect of the present invention, there is provided a permanent magnet rotor for use in a rotary motor, wherein the permanent magnet rotor is a cylindrical core having a permanent magnet therein.
An iron core forming a plurality of magnetic poles on an outer peripheral surface, and end plates respectively in contact with both end surfaces of the iron core, each including two rotation shafts integrally formed at one end thereof, and a penetrating hole penetrating the iron core. A plurality of holes are provided, and the iron core and the two rotation shafts are integrally formed by a plurality of bolts penetrating the plurality of through holes and a nut screwed to the plurality of bolts.

According to a second aspect of the present invention, in the permanent magnet rotor according to the first aspect, each of the permanent magnets inside the iron core has a rectangular flat plate shape, and the rectangular front and rear surfaces have polarities different from each other. The permanent magnets of the four permanent magnets have an angle formed by the pole faces of the permanent magnets of each other, and the magnetic pole faces of adjacent permanent magnets face each other with the same polarity. As described above, the longitudinal direction is inserted and arranged along the axial direction of the iron core.

According to a third aspect of the present invention, in the permanent magnet rotor according to the first aspect, the permanent magnet inside the iron core is a rectangular flat plate having at least one set of sides having substantially the same size as the diameter of the iron core. A single permanent magnet having a shape whose front and back surfaces are magnetic pole surfaces having polarities different from each other, wherein the permanent magnet is inserted in the axial direction of the iron core such that the at least one side crosses the central axis of the iron core. It is characterized by being arranged.

According to a fourth aspect of the present invention, in the permanent magnet rotor according to any one of the first to third aspects, the iron core is formed by laminating a plurality of thin plate-shaped iron pieces in the axial direction of the iron core. It is characterized.

[0012]

FIG. 1 shows the basic structure of a four-pole permanent magnet rotor according to one embodiment of the present invention. The permanent magnet rotor shown in this figure does not have a structure in which the rotation axis of the rotor penetrates the center axis of the rotor core, but divides the rotation axis into two parts and attaches one end of each rotation axis to a conventional rotor core. End plates provided at both ends are integrally formed. In FIG. 1, reference numeral 1 denotes one rotating shaft of the permanent magnet rotor in the present embodiment, and an end plate 1a is integrally formed at one end of the rotating shaft 1 on the side in contact with the rotor core 3. Reference numeral 2 denotes the other rotating shaft of the permanent magnet rotor. Like the rotating shaft 1, an end plate 2a is integrally formed at one end on the side in contact with the rotor core 3.

The rotor core 3 is formed by laminating a number of cross-shaped slots in a circular thin iron plate in the axial direction, and each slot has four flat permanent magnets. 4, 5, 6, and 7 are inserted and arranged. As shown, the four permanent magnets 4, 5, 6, and 7 are inserted and arranged such that the surfaces facing the adjacent permanent magnets have the same polarity.

Further, through holes 1b, 1b, ..., 2b, 2b, ..., 3 through which the bolts 8, 8, ... pass through the above-mentioned rotating shafts 1, 2 and rotor core 3, respectively.
a, 3a, ... are perforated. And bolt 8,
Are passed through these through holes and are fixed by nuts 9, 9,..., So that the rotating shafts 1, 2 and the rotor core 3 are integrally formed. At this time, the respective central axes of the rotating shafts 1 and 2 and the rotor core 3 are assumed to coincide.

According to the above-described permanent magnet rotor, since the rotating shaft does not penetrate the center of the rotor core as in the prior art, the width of the permanent magnet inserted and arranged inside the rotor core is extended to the center. become able to. This allows
The area of the surface of the permanent magnet (the surface in the radial direction of the rotor) can be increased, and the magnetic flux density of the magnetic pole formed on the outer peripheral surface of the rotor core 3 can be increased.

[Other Embodiments] As another embodiment, the structure of a rotor core in the case where the number of magnetic poles is two will be described below. FIG. 2 is a front view of the rotor core when the number of magnetic poles is two in the permanent magnet rotor shown in FIG. 1 as viewed from the axial direction. In this figure, a rotor core 10 is formed by providing a single-letter slot passing through the center point of a circular thin-plate iron piece, and laminating a large number of the slots in the axial direction. The permanent magnet 11 is inserted and arranged. In addition, the rotor core 10
In the same manner as the rotor core 3 described above, bolts 8, 8,.
, Through which through holes 10a are passed.

As shown in FIG. 1, both end surfaces of the rotor core 10 are connected to end plates 1a, 2a formed integrally with the rotating shafts 1, 2.
, And the bolts 8, 8,.
, 2b, 2b, ..., and 10a, 10a, ..., and fixed by nuts 9, 9, ..., can form a two-pole permanent magnet rotor.

When the two-pole permanent magnet rotor thus configured is compared with the conventional two-pole permanent magnet rotor shown in FIG. 5, the permanent magnet rotor according to the present embodiment has a rotating shaft penetrating the rotor core. Is not present, the surface area of the permanent magnet can be increased. As a result, even in a permanent magnet rotor having a small number of poles, the magnetic flux density of the magnetic flux appearing on the circumferential surface of the rotor core can be made higher than before.

In this embodiment, the number of magnetic poles is two and four.
Although the pole permanent magnet rotor has been described, the number of magnetic poles is not limited to the above-described embodiment, and a permanent magnet rotor having any other number of magnetic poles can be realized. Further, when configuring the rotor core, it is needless to say that the shape of the laminated sheet iron pieces can take various shapes without departing from the gist thereof.

[0020]

As described above, claim 1 or claim 2
According to the permanent magnet rotor described in (1), the rotating shaft does not penetrate the center axis of the rotor core, so that the surface area of the permanent magnet provided inside the rotor core can be increased, and the conventional permanent magnet rotor If the rotor has the same diameter, the surface area of the permanent magnet per one pole of the rotor core can be increased. As a result, the amount of magnetic flux per pole generated on the outer peripheral surface of the rotor core (the surface facing the stator) can be increased and the magnetic flux density of each pole can be increased, so that the torque generated by the permanent magnet motor can be increased. , And a small-sized motor capable of obtaining a large output can be manufactured.

According to the permanent magnet rotor of the third aspect, even in a permanent magnet rotor having a small number of poles, the surface area of the permanent magnet provided inside the rotor core can be widened, so that the conventional permanent magnet rotor can be used. As compared with the above, the torque generated by the permanent magnet motor can be increased, and a small-sized motor capable of obtaining a large output can be manufactured.

Further, according to the permanent magnet rotor of the present invention, since the rotor iron core is formed by laminating the thin iron pieces, the iron loss can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of each part of a four-pole permanent magnet rotor according to an embodiment of the present invention.

FIG. 2 is a front view showing a structure of a two-pole permanent magnet rotor according to another embodiment of the present invention.

3A and 3B are diagrams illustrating a structure of a conventional four-pole permanent magnet rotor, where FIG. 3A is a front view of a rotor core, and FIG. 3B is a side view of the permanent magnet rotor.

FIG. 4 is a perspective view showing the appearance of each part of the four-pole permanent magnet rotor.

FIG. 5 is a front view showing the structure of a conventional two-pole permanent magnet rotor.

[Explanation of symbols]

 1, 2 Rotating shaft 1a, 2a End plate 1b, 2b, 3a, 10a Through hole 3,10 Rotor core 4,5,6,7,11 Permanent magnet 8 Bolt 9 Nut

Claims (4)

[Claims] 1. A permanent magnet rotor used for a rotary motor, comprising: a cylindrical iron core having a permanent magnet therein and forming a plurality of magnetic poles on an outer peripheral surface; and both ends of the iron core. End plates respectively in contact with the surfaces, each having two rotating shafts integrally formed at one end thereof, a plurality of through holes penetrating the iron core, and a plurality of bolts penetrating the plurality of through holes A permanent magnet rotor, wherein the iron core and the two rotating shafts are integrally formed by a nut screwed to the plurality of bolts. 2. The permanent magnets inside the iron core are four permanent magnets each having a rectangular flat plate shape, and the rectangular front and rear surfaces having magnetic pole surfaces having polarities different from each other. The permanent magnets are inserted and arranged along the axial direction of the iron core such that the angle between the pole faces of the permanent magnets is a right angle and the pole faces of adjacent permanent magnets face each other with the same pole. The permanent magnet rotor according to claim 1, wherein: 3. The permanent magnet inside the iron core has a rectangular flat plate shape in which at least one set of sides has substantially the same size as the diameter of the iron core, and its front and rear surfaces are magnetic pole surfaces having different polarities. 2. The permanent magnet rotor according to claim 1, wherein the at least one set of sides is inserted in an axial direction of the iron core such that the at least one side crosses a central axis of the iron core. 3. . 4. The permanent magnet rotor according to claim 1, wherein the iron core is formed by laminating a plurality of thin iron pieces in the axial direction of the iron core.