JP2001061245A - Permanent magnet rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify assembling by reducing the number of components and prevent deterioration of motor characteristics by preventing generation of leakage flux. SOLUTION: Three kinds of yokes which are a layer 1, where yoke poles 20 of N poles are connected, a layer 2 where both yoke poles 20 of N poles and yoke poles 20 of S poles are not connected respectively, and a layer 3 where yoke poles 20 of S poles are connected are formed. Poles of a permanent magnet 16 are so inserted that the same poles face each other, sandwiching one pole of the yoke poles 20. The respective members are fixed by using cementing or the like such that the yoke poles 20 of N poles and the yoke poles 20 of S poles, which have sufficient thickness in order so as not to generate leakage flux, sandwitch the layers 2 where both the yoke poles 20 are both not connected, to parts between the layers 1 wherein the yoke poles 20 of N poles are connected and the layers 3 wherein the yoke poles 20 of S poles are connected. Thus a unified permanent magnet/yoke structure body 14 is formed. By forcibly pushing in and fixing a shaft 12 to the permanent magnet/ yoke structural body 14, a rotor main body 10 is formed.

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 in which permanent magnets and yokes are alternately arranged in a circumferential direction.

[0002]

2. Description of the Related Art Examples of a conventional permanent magnet type rotor in which permanent magnets and yokes are alternately arranged in the circumferential direction are disclosed in, for example, JP-A-63-23542 and JP-A-63-23563. JP-A-92246. JP-A-63
The technology disclosed in JP-A-23542 and JP-A-63-92246 is to form a structure by alternately arranging a plurality of permanent magnets and fan-shaped yokes in the circumferential direction, and to form both ends of the structure. A non-magnetic end plate is placed on the surface, the end plate and the structure are connected with bolts, the structure consisting of the permanent magnet and the yoke is fixed to the end plate, and the end plate is fixed to the shaft by shrink fitting. are doing.

[0003] Japanese Patent Application Laid-Open No. 7-31852 has a structure in which permanent magnets and yokes are alternately arranged in the circumferential direction. A method for integrally molding a permanent magnet, a yoke, and a shaft with a resin is disclosed.

[0004]

However, Japanese Patent Application Laid-Open Nos. 63-23542 and 63-9224 describe the above.
The method described in Japanese Patent Publication No. 6 has a problem that assembly is troublesome due to a large number of parts, and a large torque cannot be transmitted due to a small contact area between the end plate and the shaft.

Further, since the number of components is large and assembly is troublesome, the solution has been solved by integrally molding the permanent magnet and the yoke with resin as shown in Japanese Patent Application Laid-Open No. 7-31852.

However, in the technique disclosed in Japanese Patent Application Laid-Open No. Hei 7-31852, when adjacent parts are connected at the inner periphery of the yoke in order to reduce the number of parts, a leakage magnetic flux is generated at the connecting part and an effective magnetic flux is generated. And the motor characteristics deteriorate.

In view of the above problems, the present invention provides a permanent magnet type rotor that reduces the number of parts, simplifies assembly, and prevents generation of magnetic flux leakage to prevent deterioration of motor characteristics. It is intended to provide.

[0008]

According to a first aspect of the present invention, there is provided a permanent magnet type rotor comprising a plurality of permanent magnets arranged at regular intervals in a circumferential direction, and a substantially fan-shaped yoke pole arranged between the permanent magnets. In the permanent magnet type rotor constituted by the yoke main body, the yoke main body includes a first layer provided on the inner periphery with a connecting portion connecting only the yoke poles constituting the N pole, and a yoke of the N pole and the S pole. A third layer provided on the inner periphery with a connecting portion connecting only the second layer to which the poles are not connected to each other and the yoke pole constituting the S pole.
The permanent magnet / yoke structure is constituted by interposing a second layer between the first layer and the third layer to form a permanent magnet / yoke structure. The feature is that the shaft is press-fitted into the shaft.

The permanent magnet type rotor according to the second aspect is characterized in that the shaft is press-fitted into the inner peripheral surface of the joint between the first and third layers.

A permanent magnet type rotor according to a third aspect is characterized in that the surface of the permanent magnet / yoke structure is resin-molded and a boss serving as a shaft is integrally formed.

According to a fourth aspect of the present invention, there is provided the permanent magnet type rotor, wherein a non-magnetic material is used for the shaft.

In the permanent magnet type rotor according to the first aspect of the present invention, three types of layers are laminated to form a permanent magnet / yoke structure, and a shaft is press-fitted into the permanent magnet / yoke structure. Therefore, the number of parts can be reduced, the assembly can be simplified, and further, the generation of leakage magnetic flux can be prevented by the second layer, so that the characteristics of the motor can be prevented from deteriorating.

In the permanent magnet type rotor according to the second aspect, since the shaft is press-fitted into the inner peripheral surface of the connecting portion between the first and third layers, the contact area between the shaft and the yoke main body. Becomes large, and a large torque can be transmitted.

In the permanent magnet type rotor according to the third aspect, since the yoke main body, the permanent magnet and the boss are integrally and firmly adhered to each other, high accuracy and strength can be provided.

In the permanent magnet type rotor according to the fourth aspect, by using a nonmagnetic material for the shaft, the inner diameter of the yoke body can be fixed to the shaft by a method such as knurling or shrink fitting. Since no leakage magnetic flux is generated and the contact area is large, a large torque can be transmitted.

[0016]

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of a rotor main body 10. The rotor main body 10 has a substantially cylindrical permanent magnet / yoke structure 14, and an axial direction of a central portion of the permanent magnet / yoke structure 14. And a shaft 12 that is press-fitted into the shaft.

FIG. 2A is a sectional view of the permanent magnet / yoke structure 14. The permanent magnet / yoke structure 14 is located in the yoke main body 18 and the circumferential direction of the yoke main body 18. A plurality of permanent magnets 16 are arranged between the yoke poles 20 at equal intervals in the circumferential direction so as to alternately have different poles.

The yoke main body 18 is formed by laminating thin steel plates. In the present invention, there are three types of laminated steel plates. That is, as shown in FIGS. 1 and 2, the layer 1 where the N pole of the yoke pole 20 is connected, and the layer 2 where the N pole and the S pole of the yoke pole 20 are not connected as shown in FIG.
And three kinds of yoke structures of a layer 3 in which the S pole of the yoke pole 20 is connected.

As shown in FIG. 2, the layer 1 to which the N pole of the yoke pole 20 is connected is formed by integrally laminating the respective bases of the yoke pole 20 to be the N pole at a ring-shaped connecting portion 22 to form an S pole. The yoke poles 20 are disposed between the N-pole yoke poles 20 and similarly laminated.

As shown in FIG. 3, the layer 2, which is not connected to both the N pole and the S pole, is formed by laminating yoke poles 20 having a substantially sector shape in the circumferential direction.

Further, as shown in FIG. 4, the layer 3 to which the S poles of the yoke poles 20 are connected is formed by laminating the bases of the yoke poles 20 to be the S poles at a ring-shaped connecting portion 24.
The yoke poles 20 serving as the north poles are arranged between the yoke poles 20 of the south pole and are similarly laminated. The inner diameters of the connecting portions 22 and 24 of the yokes are set so that the shaft 12 can be press-fitted.

As described above, the layer 1 where the N pole yoke poles 20 are connected, the layer 2 where the N pole and S pole yoke poles 20 are not connected, and the layer 3 where the S pole yoke pole 20 are connected.
The three types of yokes are formed, and the poles of the permanent magnet 16 are inserted so as to face each other with one pole of the yoke pole 20 interposed therebetween. Then, as shown in FIG. Layer 3 where connected layer 1 and yoke pole 20 of S pole are connected
In the meantime, an integrated permanent magnet in which the N pole and the S pole yoke poles 20 each having a sufficient thickness so as not to generate a leakage magnetic flux are fixed to each other by bonding or the like with the layer 2 sandwiched between the layers 2 not connected to each other. A yoke structure 14 is formed.

Then, as shown in FIG. 1, the rotor body 10 is formed by press-fitting and fixing the shaft 12 whose surface has been knurled into the permanent magnet / yoke structure 14.

Here, since the permanent magnet and yoke structure 14 is fitted to the shaft 12 by the connecting portions 22 and 24, an end plate or the like is not required as in the conventional case, so that the number of parts is reduced and the assembly is reduced. Is simplified. The fitting portion between the outer peripheral surface of the shaft 12 and the inner peripheral surface of the permanent magnet / yoke structure 14 is formed by a layer 1 in which the N pole yoke poles 20 are connected and a layer 3 in which the S pole yoke poles 20 are connected. It is a layer portion of the inner connecting portions 22 and 24, so that the fitting portion to the shaft 12 can have a sufficient axial length.
High accuracy and strength can be ensured, and large torque can be transmitted.

Further, between the layer 1 to which the N-pole yoke pole 20 is connected and the layer 3 to which the S-pole yoke pole 20 is connected, a layer 2 to which both the N-pole and S-pole yoke poles 20 are not connected. Is provided, preventing the occurrence of leakage magnetic flux and without deteriorating the characteristics of the motor.

By using a non-magnetic material such as stainless steel for the shaft 12, even if the inner diameter of the yoke main body 18 is fixed by a method such as knurling or shrink fitting,
No leakage flux is generated, and the shaft 12
The contact area between the shaft and the yoke main body 18 is large, so that a large torque can be transmitted.

(Second Embodiment) FIG. 5 is a sectional view of a rotor body 10 according to a second embodiment.

The permanent magnet / yoke structure 14 having the same structure as that of the first embodiment is molded and fixed with a resin 30. In this case, a boss 32 instead of a shaft is provided.
Are integrally formed. When forming the boss 32, a serration 34 for fixing the shaft 12 is integrally formed inside the boss 32. Then, the small diameter portion 12a at the end of the shaft 12 is inserted through the serration 34,
By screwing the nut 36 through the washer 38,
The shaft 12 and the resin-molded permanent magnet / yoke structure 14 are integrated.

As a result, in addition to the effects of the first embodiment, the rotor body 10 having high accuracy and strength can be formed, in which the yoke body 18 and the permanent magnet 16 and the boss 32 are more firmly adhered to each other. . In addition, by integrally molding the shaft 12 and the boss 32, it is possible to apply to various types of motors.

[0031]

As described above, according to the permanent magnet type rotor of the present invention, the number of parts is reduced, the assembly is simplified, the generation of leakage magnetic flux is prevented, and the characteristics of the motor are deteriorated. And a large torque can be transmitted. In addition, sufficient strength that can withstand molding and handling can be secured, and by being integrally molded with a shaft or a boss, application to various types of motors is possible.

[Brief description of the drawings]

FIG. 1B shows a rotor main body according to an embodiment of the present invention.
FIG. 3 is a sectional view taken along line AA of FIG.

FIGS. 2A and 2B are a cross-sectional view and an arrangement configuration diagram of a layer to which an N-pole yoke pole is connected according to an embodiment of the present invention.

FIGS. 3 (a) and 3 (b) show an N pole and an S pole according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view and an arrangement configuration diagram of a layer to which both yoke poles are not connected.

FIGS. 4A and 4B are a cross-sectional view and an arrangement configuration diagram of a layer to which a yoke pole of an S pole is connected according to an embodiment of the present invention.

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

[Explanation of symbols]

Reference Signs List 1 Layer connected to N pole (first layer) 2 Layer connected to neither N pole or S pole (second layer) 3 Layer connected to S pole (third layer) 10 Rotor body DESCRIPTION OF SYMBOLS 12 Shaft 14 Permanent magnet / yoke structure 16 Permanent magnet 18 Yoke main body 20 Yoke pole 22 Connecting part 24 Connecting part 30 Resin 32 Boss

Claims (4)

[Claims] 1. A permanent magnet type rotor comprising: a plurality of permanent magnets arranged at equal intervals in a circumferential direction; and a yoke main body comprising substantially sector-shaped yoke poles disposed between the permanent magnets. A first layer provided on the inner periphery with a connecting portion that connects only the yoke poles constituting the N pole, a second layer in which both the N pole and the S pole yoke poles are not connected, and a yoke constituting the S pole It is composed of three types of layers, a third layer provided on the inner periphery with a connecting portion connecting only the poles, and a second layer is interposed between the first layer and the third layer. A permanent magnet type rotor comprising a yoke structure, wherein a shaft is press-fitted into the permanent magnet / yoke structure. 2. The permanent magnet type rotor according to claim 1, wherein a shaft is press-fitted into an inner peripheral surface of a connecting portion between the first and third layers. 3. The permanent magnet type rotor according to claim 1, wherein the surface of the permanent magnet / yoke structure is resin-molded and a boss serving as a shaft is integrally formed. 4. The permanent magnet type rotor according to claim 1, wherein a non-magnetic material is used for the shaft.