JP2000156946A - Permanent magnet field system-type rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet field system-type rotor the work of which is easy, in which stress is hard to concentrate, and which eliminates drawbacks in terms of strength. SOLUTION: A laminated core 30, in which a ring-shaped connection part 32 surrounding a shaft and fan-shaped magnetic pole parts 31 whose number corresponds to the number of magnetic poles are integrally formed, is provided. In addition, square shape permanent magnets 3 which are arranged between the magnetic pole parts are provided. Then, hollow parts 34, whose corners are rounded and which are nearly rectangular, are formed in parts at the inside of the permanent magnets, which are magnetized circumferentially in alternate directions in the connection part. Central parts of the permanent magnets are exposed in the hollow parts. Inside flanges 37 are formed at the laminated core on both sides between the permanent magnets and the hollow parts, so as to come into contact with corners at the inside of the permanent magnets. Joining parts 35 between the adjacent hollow parts are extended radially, so as to connect the fan-shaped magnetic pole parts 31 to the connecting parts 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for a motor having a permanent magnet, and more particularly to a laminated iron core in which a sector-shaped magnetic pole portion is connected to a connecting portion on a rotating shaft side, and between magnetic poles. The present invention relates to a structure of a laminated core in a permanent magnet type rotor having permanent magnets arranged.

[0002]

2. Description of the Related Art When a rotor is provided with a permanent magnet, the efficiency of the motor is increased. However, since it is necessary to fix the permanent magnet to an iron core, various structural measures have been devised. Japanese Utility Model Publication No. 7-36459 filed by the present applicant includes:
Since one example is shown, it will be described with reference to FIG. In the figure, 1 is a rotating shaft, 2 is a laminated iron core, and is formed by forming an annular connecting portion 2a surrounding the rotating shaft 1 and a sector-shaped magnetic pole portion 2b of a number corresponding to the number of poles outside thereof. I have. 2c is a connecting portion between the connecting portion 2a and the magnetic pole portion 2b, 3 is a rectangular permanent magnet inserted between the magnetic pole portions 2b, 4 is a punched hole provided over the connecting portion 2a and the magnetic pole portion 2b. Are each provided with an enlarged portion 4a. Reference numerals 5 and 6 denote end plates, and reference numeral 7 denotes a non-magnetic reinforcing member filled and inserted into the punching hole 4, and may be formed by die-casting aluminum with the horizontal plates 5 and 6, or It may be formed by separately filling a non-magnetic material. Numeral 8 denotes a caulking projection, and a laminated core 2
When the laminate is punched, parallel cuts are provided at appropriate positions, and the cuts are formed in a V-shape between the cuts. As described above, since the punched holes 4 having the enlarged portions 4a are provided at both ends over the connecting portion 2a and the magnetic pole portion 2b,
The magnetic path of the connecting portion 2c between the magnetic pole portion 2b and the connecting portion 2a is reduced, and the leakage magnetic flux passing from the permanent magnet 3 through the connecting portion 2a can be reduced to improve the magnetic characteristics. In addition, since a non-magnetic reinforcing member is filled and inserted into the punched hole 4, the mechanical strength of the connection portion 2c due to the punched hole 4 is prevented from lowering, and sufficient strength against centrifugal force and torque is maintained. Thus, an effect such as a reduced number of parts and a small number of assembly steps can be obtained.

[0003]

However, according to the prior art, since the shape of the punched hole 4 is H-shaped and high precision is required for punching, punching is not easy and the yield is increased. Was a problem. In addition, since the centrifugal force applied to the permanent magnet and the magnetic pole part is received at the connection part, stress concentration easily occurs on the laminated core at the inner corner of the permanent magnet and the corner of the enlarged part of the punched hole, which is not suitable for high speed rotation Had the disadvantage of strength. Therefore, the present invention has been made in view of these problems, and has an object to provide a permanent magnet rotor that has a small leakage magnetic flux, is easy to process, does not easily generate stress concentration, and eliminates a defect in strength. Aim.

[0004]

In the permanent magnet field type rotor of the present invention, an annular connecting portion surrounding the rotating shaft and a fan-shaped magnetic pole portion corresponding to the number of poles outside thereof are integrally formed. It is provided with a formed laminated iron core, and a rectangular permanent magnet disposed between the magnetic pole portions, and inside the permanent magnet which is magnetized in a circumferential direction alternately in the connecting portion. A substantially rectangular hollow portion with rounded corners is formed in the portion, and a central portion of the permanent magnet is exposed in the hollow portion, and inner flanges are provided on both sides between the permanent magnet and the hollow portion. The laminated core is formed in contact with the inner corner of the permanent magnet, and the outer corner of the permanent magnet is formed with an outer collar on the laminated core to contact the outer corner of the permanent magnet. Yes,
The connecting portion of the inner portion of the hollow portion has a substantially cylindrical shape, and a connecting portion between adjacent hollow portions extends in the radial direction to connect the fan-shaped magnetic pole portion and the connecting portion. . Further, a cylindrical shaft is fixed inside the connecting portion, and is connected to a load via the shaft. With such a configuration, processing accuracy is reduced, processing is facilitated, stress concentration hardly occurs, and a rotor suitable for high-speed rotation can be obtained.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial sectional view on a plane perpendicular to the rotation center of the permanent magnet field type rotor of the present invention,
FIG. 2 is a radial cross-sectional view on a radial surface including a central portion and a rotation center of the permanent magnet. In the figure, a permanent magnet field type rotor 10 of the present invention includes a laminated iron core 30 and a permanent magnet 3.
3, a cylindrical shaft 20, and a side plate 24. When the permanent magnet field type rotor 10 of the present invention is used, a stator is arranged outside the rotor to form a permanent magnet type motor, but the stator is omitted.

The laminated core 30 includes a fan-shaped magnetic pole portion 31 having a number corresponding to the number of poles extending outward and a cylindrical connecting portion 32.
It is composed of a radially extending connecting portion 35 connecting the magnetic pole portion 31 and the connecting portion 32, and these are integrated. The permanent magnets 33 are inserted between the magnetic pole portions 31 that are adjacent in the circumferential direction, are magnetized in the circumferential direction, and alternate in the circumferential direction. An outer flange 36 is formed on the laminated core 30 at the outer corner portion of the permanent magnet 33 to abut the outer corner of the permanent magnet 33 to receive the centrifugal force of the permanent magnet. The laminated iron core 30 inside the permanent magnet 33 has a substantially rectangular hollow portion 3 with rounded corners.
4 are formed. A central portion between the hollow portion 34 and the permanent magnet 31 is notched, and the permanent magnet 33 is exposed in the hollow portion 34. Inner flanges 37 are formed in the laminated iron cores 30 on both sides between the hollow portion 34 and the permanent magnet 31 so as to abut against the inner corners of the permanent magnets 33. 33 is fixed by sandwiching it in the radial direction.
A connecting portion 35 extending in the radial direction is formed in the laminated core 30 between the hollow portions 34 adjacent in the circumferential direction, and the magnetic pole portion 31 and the connecting portion 32 are integrated.

The cylindrical shaft 20 comprises a cylindrical shaft cylindrical portion 21 and a cylindrical shaft end face 22. The cylindrical shaft cylindrical portion 21 is inserted inside the connecting portion 32 and fixed to each other, and the cylindrical shaft end face 22 is formed integrally with the end of the cylindrical shaft cylindrical portion 21. The side plate 24 is fixed to the cylindrical shaft end face 22 of the cylindrical shaft 20 by set screws 23 arranged in the circumferential direction, and is connected to a load (not shown). With such a configuration, the torque generated in the laminated core 30 is
Is transmitted to the load via the side plate 24.

[0008] With the above configuration, the flow of the magnetic flux of the permanent magnet 33 is as follows. Part of the magnetic flux of the permanent magnet 33 circulates through a first circulation path formed by the fan-shaped magnetic pole portion 31, the atmosphere outside the magnetic pole surface, and a stator (not shown). The other part is a sector-shaped magnetic pole part 31
And circulate through a second circulation path formed by the connecting portion 35 and the connecting portion 32. In addition, a third circulation path formed by the sector-shaped magnetic pole portion 31, the inner flange 37, and the hollow portion 34, the sector-shaped magnetic pole portion 31, the outer collar 38, and the outside of the permanent magnet 33. Circulates through a fourth circulation path formed with the atmosphere. The first circulation path is related to the torque of the motor, and the magnetic flux in the other circulation paths is a leakage magnetic flux. Third and fourth
The circulation path has a higher magnetic resistance than the first and second circulation paths, so that the leakage flux is small. Although the second circulation path has no gap, the magnetic resistance can be increased by reducing the width of the connecting portion 35, and the leakage magnetic flux of this circulation path can be suppressed to a small value.

The strength around the joint 35 is as follows. The centrifugal force of the permanent magnet 33 is received by the outer collar 36 and transmitted to the magnetic pole portion 31, so that the centrifugal force of the magnetic pole portion 31 is transmitted to the connecting portion 35, and the connecting portion 35 receives only a radial force. At this time, stress concentrates at the corner inside the permanent magnet 33 and the corner of the hollow portion 34. However, since the corners of the substantially rectangular hollow portion 34 are rounded, stress concentration in the vicinity thereof is greatly reduced. The inside corner of the permanent magnet 33 is the laminated core 3
Since there is no hollow portion in the conventional example and the width of the laminated core is larger than the width of the connecting portion, the average stress becomes smaller than the connecting portion and the stress concentration becomes small. When receiving the centrifugal force from the connecting portion 35, a stress in the connecting portion 32 is generated substantially only in the circumferential direction. The connecting portion 32 can be made thicker in the radial direction without being affected by the connecting portion 35 and the like, and the problem of strength at this portion can be easily avoided.

The easiness of working around the hollow portion 34 is as follows. The shape around the hollow portion 34 is rounded, and the stress concentration generated there is not increased. Therefore, even if the shape of the rounded portion is slightly deformed due to a processing error, the shape becomes large enough to cause stress. It will not be. Further, since the width of the laminated core at the inner corner portion of the permanent magnet 33 is wider than that of the connecting portion 35 and the average stress is reduced, the maximum stress does not increase even if the stress is concentrated, and is suppressed to a small value. Further, since the connecting portion is close to the inner corner portion of the permanent magnet 33, the stress line passing through the connecting portion 35 does not easily flow to the corner, which is also a factor that suppresses the stress concentration at the corner. in this way,
Since the stress around the hollow portion 34 is considerably suppressed as compared with the related art, the possibility that the maximum value of the stress which increases due to the processing error is greatly increased is small, and the processing is easy. Moreover, since the hollow portion 34 has a simple shape, it is not necessary to increase the processing accuracy of this portion, and the processing is easy.

[0011]

As described above, according to the present invention, the width of the connecting portion can be reduced, so that the leakage magnetic flux is suppressed, and the width of the inner corner of the permanent magnet is wider than the width of the connecting portion, and the angle of the hollow portion is reduced. Due to the roundness, stress concentration is suppressed. Therefore, the design and processing are easy, and there is an effect that a practical permanent magnet field type rotor can be provided.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a permanent magnet field type rotor of the present invention.

FIG. 2 is a radial sectional view of a permanent magnet field type rotor of the present invention.

FIG. 3 is a sectional view of a conventional permanent magnet field type rotor 10 permanent magnet field type rotor 20 cylindrical shaft 21 cylindrical shaft cylindrical part 22 cylindrical shaft end face 23 set screw 24 side plate 30 laminated iron core 31 magnetic pole part 32 connecting part 33 Permanent magnet 34 Hollow part 35 Joint part 36 Outer brim 37 Inner brim

Claims (2)

[Claims] 1. A laminated core in which an annular connecting portion surrounding a rotating shaft and a fan-shaped magnetic pole portion corresponding to the number of poles outside thereof are integrally formed, and are disposed between the magnetic pole portions. A permanent magnet field-type rotor having a rectangular permanent magnet, wherein an inner part of the permanent magnet, which is magnetized in alternate directions in a circumferential direction, of the connecting portion has a substantially rectangular shape with rounded corners. A hollow portion is formed, and a central portion of the permanent magnet is exposed to the hollow portion. On both sides between the permanent magnet and the hollow portion, inner collars are formed in the laminated core to form the permanent magnet. An outer corner of the laminated core is formed at an outer corner of the permanent magnet to abut on an outer corner of the permanent magnet; and a connection portion of an inner portion of the hollow portion is formed at the outer corner of the permanent magnet. Has a substantially cylindrical shape, and the joint between adjacent hollows extends in the radial direction and Permanent magnet field type rotor, characterized in that connecting the said connecting portion and the shape of the magnetic pole portion. 2. A permanent magnet field type rotor according to claim 1, wherein a cylindrical shaft is fixed inside said connecting portion and connected to a load via said shaft. .