JPH0686487A - Permanent magnet rotor - Google Patents

Abstract

PURPOSE:To provide a permanent magnet rotor having the highly accurate diameter in size, wherein stamped steel plates are fixed as a unitary body at an outer-surface ring part, without the occurrence of the deformation, peeling and breakdown of the outer-surface ring part by the pressure of a cutting tool during the cutting of the outer surface of a rotor. CONSTITUTION:Many stamped steel plates 3 having punched holes 2 are laminated and a laminated core 4 is formed. A permanent magnet piece is inserted into the hollow part of the laminated core formed of the punched holes 2. In this permanent magnet rotor, the stamped steel plates 3 are mutually welded with a laser beam 12 so as to form an outer-surface ring part 10 at the outside of the permanent magnet piece of the laminated core 4 in the radial direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a permanent magnet rotor,
In particular, the present invention relates to a permanent magnet rotor that does not suffer from poor outer diameter dimensional accuracy and peeling or breakage of the outer peripheral ring portion due to the rotor outer periphery cutting process after lamination.

[0002]

2. Description of the Related Art Generally, punched steel sheets punched so as to have a punching hole for inserting a permanent magnet piece are laminated to form a laminated core, and a plurality of permanent magnet pieces are formed in a cavity portion of the laminated iron core. There is known a permanent magnet rotor having a magnet inserted therein. Figure 5
Shows an exploded view of a conventional permanent magnet rotor. The conventional permanent magnet rotor 21 includes a laminated iron core 24 in which a large number of circular punched steel plates 23 having punched holes 22 are laminated, and a plurality of laminated iron cores 24 formed by the punched holes 22 and inserted into cavity portions of the laminated iron core 24. It is composed of a permanent magnet piece 25, end plates 26 arranged at both ends of the laminated iron core, and rivets 27 that tighten the both end plates 26. A rivet through hole 28 is formed between the center portion of the punched steel plate 23 and the punching hole 22 to allow the rivet 27 to pass through. Further, a rotary shaft through hole 29 for inserting the rotary shaft of the motor is provided at the center of the punched steel plate 23. A permanent magnet piece 25 is provided outside the punching hole 22.
Is formed to have a narrow outer peripheral ring portion 30. The punched steel plate 23 has a crimped portion (not shown) that fits between the center portion and the punched hole 22 at a position where it does not overlap the rivet through hole 28, and the punched steel plates 23 are integrated with each other by this crimped portion. It has been crimped. In manufacturing, after stacking the punched steel plates 23, the permanent magnet pieces 25 are inserted into the hollow portions of the punched steel plates 23 by the punching holes 22, and then the end plates 26 are applied to both end faces of the laminated iron core 24. Both end plates 26 are connected to each other by rivets 27. Further, in order to obtain the air gap between the permanent magnet rotor 21 and the magnetic pole surface of the stator and the outer diameter dimensional accuracy of the permanent magnet rotor 21 to keep the air gap constant, after the above-mentioned assembly process, the outer circumference of the permanent magnet rotor 21 is Is cut with a cutting tool.

FIG. 6 is an enlarged view of a part of the permanent magnet rotor 21 showing a cutting process of the outer circumference of the permanent magnet rotor 21.
After assembly, the outer circumference of the permanent magnet rotor 21 is cut by the cutting tool 31 so that the outer diameter dimension falls within a predetermined range. Since the cutting tool 31 moves in the circumferential direction relative to the permanent magnet rotor 21 and also moves in the axial direction P, the punched steel plate 23 is pushed in the axial direction P. In the conventional permanent magnet rotor 21, the punched steel plates 23 are not fixed to each other at the outer peripheral ring portion 30, so that the outer peripheral ring portion 30 of each punched steel plate 23 is easily retracted by the pressure of the cutting bite, as shown in FIG. , (B) as shown in FIG.

[0004]

In the conventional permanent magnet rotor described above, the punched steel sheets are fixed to each other only at the central portion by the caulking portion, and the punched steel sheets are not fixed to each other at the outer peripheral ring portion. During the cutting process, the outer peripheral ring portion may be easily deformed by the pressure of the cutting bite, resulting in poor accuracy of the outer diameter of the permanent magnet rotor, or peeling or breakage of the outer peripheral ring portion. Therefore, an object of the present invention is to solve the problem of the conventional permanent magnet rotor described above, in which punched steel plates are integrally fixed to each other at the outer peripheral ring portion, and the outer peripheral ring portion is deformed or peeled off by the pressure of the cutting tool during the cutting of the rotor outer periphery. Another object of the present invention is to provide a permanent magnet rotor having an outer diameter with high dimensional accuracy without causing any breakage.

[0005]

In order to achieve the above object, the permanent magnet rotor according to the present invention is formed by laminating a large number of punched steel plates having punching holes for inserting permanent magnet pieces to form a laminated core. In the permanent magnet rotor in which the permanent magnet pieces are inserted into the hollow portion of the laminated iron core formed by the punched holes, the peripheral edge portion of the laminated iron core is characterized in that punched steel sheets are welded to each other by a laser beam. To do.

Further, the permanent magnet rotor according to the present invention is characterized in that the punched steel plates are adhered to each other at the peripheral edge portion of the laminated core by an adhesive impregnated from the outer periphery of the laminated core.

Further, the permanent magnet rotor according to the present invention is characterized in that the punched steel sheets have an adhesive coating on the laminated surface, the laminated iron core is heated and fixed after lamination, and the punched steel sheets are fixed to each other. It is a thing.

[0008]

In the permanent magnet rotor according to the present invention, the punched steel sheets are welded to each other by the laser beam at the outer peripheral ring portion, or are adhered to each other by the adhesive impregnated from the outer periphery of the rotor, or they are mutually adhered by the adhesive coating applied beforehand. Since the entire punched steel sheets that have been fixed to each other are subjected to stress due to external force because they are heated and fixed to each other, compared with the case where the punched steel sheets are individually separated, the pressure of the cutting tool causes the permanent magnet rotor to rotate. The outer peripheral ring is less likely to be deformed.

[0009]

EXAMPLE A permanent magnet rotor of the present invention is formed by laminating a large number of punched steel plates having a plurality of punched holes to form a laminated core, and the outer peripheral ring portion of the laminated core on the outer side in the radial direction of the punched hole is welded. It is the one that is fixed together by adhesion. Embodiments of the permanent magnet rotor of the present invention will be described below with reference to the drawings. Although the main part of the present invention is to fix the outer peripheral ring part of the permanent magnet rotor, prior to the description of the main part of the present invention,
The structure of the entire permanent magnet rotor will be described.

FIG. 3 is an exploded view of a permanent magnet rotor according to an embodiment of the present invention. The permanent magnet rotor 1 has a laminated core 4 in which a large number of punched steel plates 3 having a plurality of punched holes 2 are laminated.
A plurality of permanent magnet pieces 5 inserted into the hollow portion of the laminated iron core 4 formed by the punching holes 2, a pair of end plates 6 arranged at both ends of the laminated iron core 4, and both end plates 6. It is composed of a rivet 7 to be connected. The punched steel plate 3 of the laminated iron core 4 is integrally fixed to the outer peripheral surface by a welding line W extending in the axial direction.

FIG. 4 shows a cross section of the laminated core. As shown in FIG. 4, each punched steel plate 3 has a circular shape, and has an even number of arc-shaped punched holes 2 substantially parallel to the circumference at the peripheral edge. A plurality of through holes 8 of the rivet 7 are provided between the central portion and the punching hole 2, and a rotary shaft through hole 9 into which the rotary shaft of the motor is inserted is provided in the central portion. Perforated holes 2 are fitted with permanent magnet pieces 5 each having a circular arc shape in cross section. The radially outer portion of the permanent magnet piece 5 of the laminated iron core 4 forms a thin outer peripheral ring portion 10 that guides the magnetic flux of the permanent magnet piece 5. A portion between the permanent magnet pieces 5 forms a connecting portion 11 that connects the center-side iron core portion of the punched steel plate 3 and the outer peripheral ring portion 10.

FIG. 1 shows one process for manufacturing the laminated core 4 of this embodiment. After the punched steel plates 3 are laminated to form the laminated core 4, the outer periphery of the outer peripheral ring portion 10 of the laminated core 4 is welded in the axial direction P by the laser beam 12. The welding with the laser beam 12 is performed by adjusting the output of the laser beam 12 so that the outer peripheral ring portion 10 is not deformed by the welding heat. Welding line W with laser beam 12
Are spaced apart from each other and are linearly provided in the axial direction. After welding, a permanent magnet piece 5 whose shape matches that of the punched hole 2 is inserted into the hollow portion of the laminated iron core 4 formed by the punched hole 2, and then end plates 6 are arranged on both end faces of the laminated iron core 4. , Both end plates 6 are connected by rivets 7. Next, the outer peripheral surface of the permanent magnet rotor 1 is cut with a cutting tool so that the gap between the magnetic pole surface (not shown) of the stator is within a certain range.

As described above, in the permanent magnet rotor 1 of this embodiment, the outer peripheral ring portion 10 is welded to the punched steel plates 3 by the laser beam 12, so that the outer peripheral ring portion 1 is formed.
The mechanical strength of No. 0 increases, the outer peripheral ring portion 10 retreats due to the cutting pressure during the cutting process of the rotor outer peripheral surface, the outer diameter dimension of the permanent magnet rotor 1 changes, or the outer peripheral ring portion 10 peels off. Does not break. Further, in this embodiment, since the laser beam 12 is used for welding the outer periphery of the laminated core 4, the heat-affected portion due to the welding heat can be limited to a very small amount, and the outer peripheral ring portion 10 is not thermally deformed. Good dimensional accuracy can be maintained even after welding. In the present embodiment, the welding with the laser beam 12 is performed over the entire axial direction of the permanent magnet rotor 1. However, in order to prevent deformation, the outer peripheral ring portion 10 facing the chamfered portions at both axial end portions of the permanent magnet piece 5 is opposed. You may weld only the both axial ends. In this case, it is possible to reduce the welding time and the manufacturing cost. Further, it is obvious that the welding line W is not limited to a linear shape, and can be any welding line shape for integrally welding the outer peripheral ring portion 10, for example, a wavy welding line.

Further, in the above-mentioned embodiment, after the laminated iron core is assembled, the welding is carried out by the laser beam and the permanent magnet pieces are then assembled. However, the assembly of the permanent magnet rotor is completed first, and then the laser is completed. Obviously, beam welding may be performed. An embodiment of the permanent magnet rotor according to this manufacturing method will be described below. FIG. 2 shows one manufacturing process of the permanent magnet rotor in which the laminated core and the end plate are integrally welded by a laser beam after the assembly is completed. Figure 1
According to the present embodiment, the same parts as those in FIG.
The permanent magnet piece 5 is inserted into the hollow portion of the laminated iron core 4 formed by the punching hole 2, the end plates 6 are arranged on both end faces of the laminated iron core 4, and the rivets 7 are tightened in the axial direction.
2. The outer peripheral surface of the rotor including the end plate 6 is welded in the axial direction P by 2. In this case, the output of the laser beam 12 is adjusted so that the permanent magnet piece 5 is not deteriorated by the welding heat. According to this embodiment, since the end plate 6 is integrally welded to the laminated iron core 4, the permanent magnet rotor 1 is more firmly fixed. Further, since laser beam welding is performed after the assembly, there is an advantage that the manufacturing process is convenient without changing the conventional assembly process of the permanent magnet rotor.

In the above embodiment, laser beam welding is used as a method for fixing the outer peripheral ring portions of the permanent magnet rotor to each other, but bonding may be used instead of laser beam welding. Two methods for integrally fixing the outer peripheral ring portion by adhesion will be described below. In the first method by bonding, after the assembly of the permanent magnet rotor is completed, an adhesive is impregnated between the punched steel plates from the outer circumference of the permanent magnet rotor to integrally bond the outer peripheral ring portion of the permanent magnet rotor. According to this method, the outer peripheral ring portion and the permanent magnet piece are not affected by welding heat such as deformation and deterioration.

In the second method of adhesion, a thermosetting adhesive film is applied to the laminated surface of the punched steel sheets in advance and the laminated film is laminated to form a laminated iron core. After the lamination, the entire laminated core is heated and the punched steel sheet is heated and fixed by the adhesive film. According to this method, since the application of the adhesive coating and the heat fixing are part of the assembly process of the permanent magnet rotor, the assembly process can be automated and the manufacturing can be facilitated. Further, since the heat fixing heats the entire laminated core to a relatively low temperature, it is less likely to be adversely affected by deformation or the like.

[0017]

As is apparent from the above description, the permanent magnet rotor of the present invention can be welded by a laser beam or adhesive.
Since the outer peripheral ring part is integrally fixed by the adhesive film,
The mechanical strength of the outer ring increases, and when cutting the outer circumference of the rotor after assembling the permanent magnet rotor, it is possible to prevent the outer ring of the punched steel plate from receding, deforming, or breaking due to the pressure of the cutting tool. A permanent magnet rotor with high dimensional accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing one manufacturing process of performing laser beam welding on an outer peripheral surface of a permanent magnet rotor according to the present invention.

FIG. 2 is a perspective view showing a manufacturing process in which laser beam welding is performed on the outer peripheral surface of the permanent magnet rotor according to the present invention including the assembled rear end plate.

FIG. 3 is an exploded perspective view of a permanent magnet rotor according to the present invention.

FIG. 4 is a cross-sectional view of a permanent magnet rotor according to the present invention.

FIG. 5 is an exploded perspective view of a conventional permanent magnet rotor.

FIG. 6 is a partially enlarged view of a conventional permanent magnet rotor showing one step of cutting the outer peripheral surface.

FIG. 7 is a partially enlarged view of a conventional permanent magnet rotor exemplifying poor outer diameter dimension accuracy.

[Explanation of symbols]

 1 Permanent Magnet Rotor 2 Punching Hole 3 Punching Steel Plate 4 Laminated Iron Core 5 Permanent Magnet Piece 10 Perimeter Ring Part 12 Laser Beam

Claims (3)

[Claims] 1. A laminated iron core is formed by laminating a large number of punched steel plates having punched holes for inserting permanent magnet pieces, and the permanent magnet pieces are inserted into the hollow portions of the laminated iron core formed by the punched holes. In the permanent magnet rotor configured as described above, the punched steel sheets are welded to each other by a laser beam at a peripheral edge portion of the laminated iron core. 2. A laminated iron core is formed by laminating a large number of punched steel plates having punched holes for inserting permanent magnet pieces, and the permanent magnet pieces are inserted into the hollow portions of the laminated iron core formed by the punched holes. In the permanent magnet rotor configured as described above, punched steel sheets are adhered to each other by an adhesive impregnated from the outer periphery of the laminated iron core at the peripheral edge of the laminated iron core. 3. A laminated iron core is formed by laminating a large number of punched steel plates having punched holes for inserting permanent magnet pieces, and the permanent magnet pieces are inserted into the hollow portions of the laminated iron core formed by the punched holes. In the permanent magnet rotor configured as described above, the punched steel sheets have an adhesive coating on a lamination surface, and the punched steel sheets are fixed to each other by heating and fixing the laminated iron core after lamination.