JPH0984283A - Structure for arranging rotor magnet to rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a rotor magnet easily with high positioning accuracy to a rotor while sustaining a substantially uniform clearance between the stator and the rotor. SOLUTION: The structure for arranging a rotor magnet to a rotor comprises a plurality of permanent magnets 22a-22h having a plurality of grooves 30 made in the outer circumferential surface of a rotor 16 while extending substantially in parallel with the axis of a shaft 18, substantially flat surfaces 26 being fitted while touching the inner wall face of respective elongated grooves 30, and a curved surface 28 having substantially arcuate cross-section formed oppositely to the substantially flat surfaces 26, and a tubular member 24 for covering the plurality of permanent magnets 22a-22h and holding the permanent magnets 22a-22h in the elongated grooves 30 while pressing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor magnet arrangement structure for a rotor capable of improving the magnetic characteristics of a rotor and a stator constituting a motor.

[0002]

2. Description of the Related Art Generally, a motor includes a stator core (stator core) provided with windings corresponding to a predetermined number of phases,
A plurality of permanent magnets are provided on the outer peripheral surface of the stator core, and the rotor is rotatably disposed in the hollow portion of the stator core. This type of rotor usually has a shaft (rotational axis)
The shaft has a substantially cylindrical yoke that is mounted on the shaft and rotates integrally with the shaft, and a plurality of permanent magnets that are arranged on the outer peripheral surface of the yoke at predetermined intervals.

In this case, the permanent magnet is adhered to the outer peripheral surface of the yoke through the arc-shaped inner peripheral surface, and is further covered with a cylindrical member made of fiber reinforced resin in order to surely press and hold the yoke.

[0004]

However, in the arrangement structure of the permanent magnet, the outer peripheral surface of the permanent magnet and the inner peripheral surface of the stator core are adhered to each other depending on the bonding state between the outer peripheral surface of the yoke and the arc-shaped inner peripheral surface of the permanent magnet. The clearance with the surface becomes non-uniform, which adversely affects the magnetic characteristics of the stator core and the rotor.

If the clearance between the outer peripheral surface of the permanent magnet and the inner peripheral surface of the stator core is not uniform, stress is concentrated on the cylindrical member covering the permanent magnet, which may damage the cylindrical member.

Further, there is a problem that the positioning operation of the permanent magnet is complicated when the permanent magnet is bonded to the outer peripheral surface of the yoke.

The present invention has been made in order to overcome the above-mentioned inconvenience, and the rotor magnet can be easily assembled to the rotor with high positioning accuracy, and the clearance between the stator and the rotor can be made substantially uniform. It is an object of the present invention to provide a rotor magnet disposition structure for a rotor that can be formed.

[0008]

In order to achieve the above object, the present invention provides a plurality of permanent magnets arranged at predetermined angular intervals on the outer peripheral surface of a rotor having a rotating shaft at its center. In the structure, a plurality of long grooves are formed on the outer peripheral surface of the rotor corresponding to the arrangement of the permanent magnets and extend substantially parallel to the axis of the rotating shaft, and contact the inner wall surfaces of the respective long grooves. A plurality of permanent magnets having a substantially flat surface to be inserted and a curved surface having a substantially arcuate cross section formed on the side opposite to the substantially flat surface, and a plurality of permanent magnets covered to form long grooves in the permanent magnets. And a cylindrical member which is pressed and held by.

In this case, it is preferable that the curved surfaces each having a substantially arcuate cross-section formed on each of the plurality of permanent magnets are formed in a concentric shape around the axis of the rotating shaft. Further, it is preferable that the cylindrical member is made of a fiber-reinforced resin made of a non-magnetic material.

According to the present invention, by inserting a plurality of permanent magnets into the long groove of the rotor so that their substantially flat surfaces are in contact with each other, the permanent magnets can be easily assembled to the rotor with high positioning accuracy. It is possible to form the clearance between the stator and the rotor substantially uniformly.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the arrangement structure of rotor magnets for a rotor according to the present invention will be given.
This will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a motor. The motor 10 includes a stator core 14 on which a three-phase winding 12 is mounted, and a rotor rotatably disposed in a hollow portion of the stator core 14. 16 and. The stator core 14 is formed by integrally laminating a plurality of laminated steel plates.

The rotor 16 has a shaft 18 functioning as a rotation shaft, a substantially cylindrical yoke 20 to which the shaft 18 is attached and rotates integrally with the shaft 18, and an outer peripheral surface of the yoke 20 has a predetermined angle. A plurality of permanent magnets 22a to 22h, which are spaced apart from each other, and the permanent magnet 22.
and a cylindrical member 24 for holding the permanent magnets 22a to 22h with respect to the yoke 20 by covering a to 22h. The permanent magnets 22a (22b to 22h) are formed of, for example, Nd-Fe-B based permanent magnets, and the cylindrical member 24 is made of a non-magnetic material, for example, a fiber reinforced resin such as glass fiber. It is formed.

The plurality of permanent magnets 22a to 22h have substantially the same shape, and as shown in FIG.
8 is formed in a long, semi-cylindrical shape that extends substantially parallel to the axis of 8, and one side surface that faces each other is formed into a substantially flat surface 26 having a rectangular shape. The other side surface is formed into a curved surface 28 having a substantially arcuate cross section. The substantially arcuate curved surface 28 is formed concentrically around the axis of the shaft 18.

A plurality of long grooves 30 are formed on the outer peripheral surface of the yoke 20 so as to be separated from each other by a predetermined angle along the circumferential direction and extend along the axial direction of the shaft 18. The long grooves 30 have a substantially flat surface 26. The permanent magnets 22a to 22h are respectively inserted into contact with.

The motor 10 to which the rotor magnet disposition structure for the rotor according to the embodiment of the present invention is applied is basically constructed as described above. Next, its function and effect will be explained. To do.

First, FIG. 4 shows a case where the permanent magnets 22a to 22h are assembled to the outer peripheral surface of the yoke 20 using the jig 32. The jig 32 has a substantially cylindrical shape surrounding the outer peripheral surface of the yoke 20, and a plurality of recesses 34 extending in the axial direction are formed on the hollow inner peripheral surface. By arranging the concave portion 34 and the long groove 30 formed on the outer peripheral surface of the yoke 20 so as to face each other, the permanent magnets 22a (22b to 22b) are provided.
The hole in which the h) is arranged is defined, and the permanent magnets 22a (22b to 22h) are easily and smoothly inserted along the hole.

In this case, a curved surface portion 36 corresponding to the curved surface 28 of the permanent magnets 22a (22b to 22h) is formed on the inner wall surface of the recess 34, and the curved surface portion 36 of the jig 32 and the permanent magnets 22a (22b to 22h) are formed. ), The polarity of the permanent magnets 22a (22b to 22h) on the curved surface 28 side can be accurately assembled without reversing the polarity on the substantially flat surface 26 side.

For example, as a comparative example, when the permanent magnets 22a to 22h are assembled by using the jig 40 in which the inner wall surface of the recess 34 is formed on the substantially flat surface 38, a plurality of permanent magnets 2 are assembled.
2a to 22h can be assembled in a regular arrangement as shown in FIG. 5, but on the other hand, as shown in FIG. 6, the substantially flat surface 26 and the curved surface 28 of the permanent magnet 22a are opposite to each other. There is a possibility that the polarities of the S pole and the N pole of the permanent magnet 22a may be mistakenly reversed.

In this case, as shown in FIG. 7, the corners 42a and 42b of the permanent magnet 22a whose polarities are reversed are projected angularly, so that a plurality of permanent magnets 22a to 22h covered by the cylindrical member 24 are formed. The outer peripheral surface of is not formed concentrically. As a result, stress concentrates on the portion of the cylindrical member 24 that covers the reversely attached permanent magnet 22a, and the cylindrical member 24 is easily damaged. When the rotor 16 including the permanent magnets 22a whose polarities are reversed is incorporated in the hollow portion of the stator core 14 shown in FIG. 1, the stator core 14 and the permanent magnets 22a to 22a.
There is a problem that the clearance with 22h becomes non-uniform and that the corners 42a and 42b contact the inner peripheral surface of the stator core 14 so that the motor cannot be smoothly rotated.

In the present embodiment shown in FIG. 4, the permanent magnet 22 is used.
By using the jig 32 having the curved surface portion 36 corresponding to the curved surface 28 of a to 22h, it is possible to easily position and assemble the permanent magnets 22a to 22h without reversing the polarities of the permanent magnets 22a to 22h. Becomes

Then, a plurality of permanent magnets 22a to 22a are provided on the outer peripheral surface.
The cylindrical member 24 is mounted on the rotor 16 in which 22h is arranged, and the permanent magnets 22a to 22h are attached by the cylindrical member 24.
Is coated. Since the permanent magnets 22a to 22h are pressed and held in the long groove 30 of the yoke 20 by the cylindrical member 24, the permanent magnets 22a to 22h are separated from the long groove 30 by the centrifugal force generated by the rotating action of the rotor 16. Can be stopped.

In this embodiment, the permanent magnets 22a to 22a are formed by contacting the long groove 30 formed in the yoke 20 with the substantially flat surface 26.
By inserting 2h, the clearance between the stator core 14 and the rotor 16, that is, the stator core 14
Inner circumferential surface of the permanent magnets 22a to 22h and the curved surface 2 having a substantially arc shape.
8 can be formed uniformly, and the magnetic characteristics of the stator core 14 and the rotor 16 can be improved.

Further, by inserting and inserting the permanent magnets 22a to 22h along the long groove 30 formed in the yoke 20, the permanent magnets 22a to 22h can be positioned easily and accurately.

Further, the substantially arcuate curved surface 28 of the plurality of permanent magnets 22a to 22h held in the long groove 30 of the yoke 20.
Are formed concentrically around the shaft 18, so that the cylindrical member 2 covering the permanent magnets 22a to 22h is formed.
It is possible to prevent stress from concentrating on 4.

[0026]

According to the arrangement structure of the rotor magnet for the rotor according to the present invention, the following effects can be obtained.

That is, by inserting a permanent magnet into a long groove formed on the outer peripheral surface of the rotor with a substantially flat surface in contact therewith, the clearance between the inner peripheral surface of the stator and the substantially arc-shaped curved surface of the permanent magnet is made uniform. It is possible to improve the magnetic characteristics of the stator and the rotor.

By inserting the permanent magnet along the long groove formed on the outer peripheral surface of the rotor, the permanent magnet can be positioned easily and accurately.

Further, since the substantially arc-shaped curved surfaces of the plurality of permanent magnets held in the long groove are formed concentrically around the rotation axis, stress is concentrated on the cylindrical member covering the permanent magnets. Can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view of a motor to which a rotor magnet disposition structure for a rotor according to an embodiment of the present invention is applied.

FIG. 2 is a perspective view of a rotor incorporated in the motor shown in FIG.

3 is a perspective view of a permanent magnet arranged on the outer peripheral surface of the rotor shown in FIG.

FIG. 4 is a plan view showing a state where the permanent magnet shown in FIG. 3 is assembled to the outer peripheral surface of the rotor by using a jig.

FIG. 5 is a plan view showing a state where the permanent magnet shown in FIG. 3 is assembled to the outer peripheral surface of the rotor by using a jig which is a comparative example.

FIG. 6 is a plan view showing a state where the permanent magnet shown in FIG. 3 is assembled to the outer peripheral surface of the rotor by using a jig which is a comparative example.

FIG. 7 is a perspective view of a rotor including permanent magnets with reversed polarities.

[Explanation of symbols]

10 ... Motor 12 ... Winding 14 ... Stator core 16 ... Rotor 18 ... Shaft 20 ... Yoke 22a-22h ... Permanent magnet 24 ... Cylindrical member 26 ... Substantially flat surface 28 ... Curved surface 30 ... Long grooves 32, 40 ... Jig 34 ... Recessed portion 36 ... Curved part 42a, 42b ... Corner part

Claims (3)

[Claims] 1. A structure in which a plurality of permanent magnets are arranged at predetermined angular intervals on the outer peripheral surface of a rotor having a rotating shaft at the center, and the permanent magnets are arranged on the outer peripheral surface of the rotor. A plurality of long grooves extending substantially parallel to the axis of the rotating shaft, a substantially flat surface inserted into contact with the inner wall surface of each long groove, and a side opposite to the substantially flat surface. A plurality of permanent magnets each having a curved surface having a substantially arcuate cross-section formed in the above; and a cylindrical member that covers the plurality of permanent magnets and presses and holds the permanent magnets in a long groove. Arrangement structure of rotor magnets. 2. The rotor according to claim 1, wherein curved surfaces each having a substantially arcuate cross section formed in each of the plurality of permanent magnets are formed in concentric circles with the axis of the rotating shaft as a center. Arrangement structure of rotor magnets for. 3. The arrangement structure of a rotor magnet for a rotor according to claim 1 or 2, wherein the cylindrical member is formed of a fiber reinforced resin made of a non-magnetic material.