JP3788186B2 - Electric motor rotor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotor of an electric motor used for various industrial machines.
[0002]
[Prior art]
In recent years, in order to reduce the size, diameter, and performance of electric motors, there is an increasing need for higher density windings and space saving at the ends of the windings. Especially in AC servo motors used for driving robots and NC machine tools as industrial equipment, in order to respond to higher speeds, space savings and higher output of robots and NC machine tools, the rotation of the motor A magnet with an extremely high magnetic flux density is used for the child, and high assembly accuracy is required in terms of imbalance and cogging torque.
[0003]
Hereinafter, a conventional rotor of an electric motor will be described.
[0004]
In FIG. 3, 31 is a rotating shaft of the rotor, 32 is a laminated iron core obtained by laminating and integrating a large number of magnetic plates, 33 is a plurality of segment magnets attached to the laminated iron core 32 by an adhesive, and 34 is a segment. Protrusions 35 for positioning and preventing idling when the magnets are bonded are caulking parts for laminating and fixing a large number of magnetic plates. The rotating shaft 31 is press-fitted and fixed in the center of the laminated iron core 32 to serve as a rotor. Magnetize before installation.
[0005]
[Problems to be solved by the invention]
However, the above conventional rotor has the following problems.
[0006]
First, when stacking and integrating a large number of magnetic plates with pack caulking, the influence of the caulking part pops out to the segment magnet mounting surface (outer peripheral surface) side, and the segment magnet and laminated iron core cannot be brought into close contact with each other. There was a possibility of adversely affecting various characteristics of the motor, such as increasing the unbalance of the child and increasing the cogging torque after magnetization.
[0007]
Also, when laminating a large number of magnetic plates by welding, if the segment magnet mounting surface is welded, the welding marks (beads) may protrude from the magnet mounting surface, which may adversely affect the various characteristics of the motor as with pack caulking. there were. In order to prevent this, it is only necessary to weld the protruding part of the laminated iron core, but if the width of the protruding part is increased, the gap of the pole conversion part between the magnets will become larger, resulting in increased cogging torque. The width of the part could not be increased.
[0008]
In addition, since a magnet having a high magnetic flux density is used to have curved portions on the inside and outside, and polishing processing with different curvatures is necessary and expensive, there has been a demand for an inexpensive rotor.
[0009]
An object of the present invention is to solve the above-described conventional problems, and to provide an inexpensively reliable rotor for an electric motor that can attach a segment magnet with high accuracy and can suppress an increase in unbalance and cogging torque. And
[0010]
[Means for Solving the Problems]
The present invention for solving the above problems is the rotor of the electric motor which is fixed to the segment magnets on the surface of the laminated core and integrated by laminating punched a number of magnetic plates, the segment magnets circumferentially on the outer peripheral portion shape by polyhedral A magnetic plate having a plurality of protrusions arranged at equal intervals, a recess provided between the protrusions, and a segmented magnet having a cross section of the protrusion, and the recess is integrated with a pack caulking. It is the rotor of the electric motor provided in the outer side of the crimping | crimped part to change .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention for solving the above problems is the rotor of the electric motor which is fixed to the segment magnets on the surface of the laminated core and integrated by laminating punched a number of magnetic plates, the segment magnets circumferentially on the outer peripheral portion shape by polyhedral A magnetic plate having a plurality of protrusions arranged at equal intervals, a recess provided between the protrusions, and a segmented magnet having a cross section of the protrusion, and the recess is integrated with a pack caulking. This is a rotor of an electric motor characterized by being provided outside the caulking part to be transformed , and absorbs distortion when the laminated iron core is integrated into the concave part, and at the same time, when adhering the segment magnet, the extra adhesive is concaved. Can be absorbed.
[0012]
In addition, since the mounting surface of the segment magnet to the laminated core can be made flat and the polishing process can be facilitated, the segment magnet can be manufactured at a low cost, and the thickness of the segment magnet becomes non-uniform so that the cogging torque can be reduced. .
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
( Reference Example )
In FIG. 1, 11 is a rotating shaft, 12 is a ring-shaped laminated iron core obtained by laminating and integrating a large number of magnetic plates, 13 is four segment magnets attached to the laminated iron core 12 with an adhesive, and 14 is Four projections for bonding and positioning the segment magnets 13 are provided at equal intervals in the circumferential direction of the magnetic plate. Reference numeral 15 denotes a caulking portion for integrating the laminated magnetic plates by pack caulking, and reference numeral 16 denotes a recess provided outside the caulking portion 15 between the protruding portions of the magnetic plate.
[0015]
First, after forming a ring-shaped laminated iron core 12 integrated with the crimping portion 15 while laminating a large number of magnetic plates, the rotary shaft 11 is press-fitted and fixed to the central portion of the laminated iron core 12. Furthermore, a rotor is obtained by applying an adhesive between the projecting portions 14 and bringing the four segment magnets 13 into contact with the projecting portions 14 in one direction to fix the positioning. .
[0016]
When the laminated iron core 12 is formed, distortion due to caulking can be absorbed by the concave portion 16, and the segment magnet 13 can be attached to the laminated iron core 12 with high accuracy. Therefore, there is no adverse effect on the characteristics of the motor, such as an increase in cogging torque and occurrence of rotor imbalance.
[0017]
Further, when the segment magnet 13 is bonded, the recess 16 also functions as an adhesive guide groove for the adhesive, so that the bonding process can be stabilized. It also serves as a reservoir for absorbing excess adhesive.
[0018]
(Example 1 )
In FIG. 2, 21 is a rotating shaft, 22 is a quadrangular laminated core obtained by laminating and integrating a large number of magnetic plates, and 23 is a segment having four cross sections attached to the laminated core 22 by an adhesive. Magnets 24 are projections for adhering and positioning the segment magnet 23, and are provided at four locations at equal intervals in the circumferential direction of the magnetic plate. Reference numeral 25 denotes a caulking portion for integrating the laminated magnetic plates by pack caulking, and 26 denotes a concave portion provided outside the caulking portion 25 between the protrusions .
[0019]
First, a polyhedral laminated core 22 is obtained in which a large number of magnetic plates are punched and laminated and integrated with a crimping portion 25 . Thereafter, the rotary shaft 21 is press-fitted and fixed in the center of the laminated iron core 22. Further, an adhesive is applied between the projecting portions 24 and the four segment magnets 23 are brought into contact with one direction of the projecting portions 24 to be positioned and fixed to obtain a rotor, which is magnetized before being incorporated into the electric motor.
[0020]
When the laminated iron core is integrally formed by the crimping portion 25 , the concave portion 26 can absorb the distortion caused by the crimping, so that the mounting accuracy of the segment magnet can be ensured. Therefore, as in the reference embodiment , there is no adverse effect on the characteristics of the motor, such as an increase in cogging torque and occurrence of rotor imbalance.
[0021]
As described above, in Example 1 , the shape of the laminated core in the reference example is changed from a ring shape to a polyhedron, and the segment magnet is shaped like a cone, and the mounting surface side can be made flat so that machining is easy. Segment magnets can be manufactured at low cost.
[0022]
Furthermore, since the cross section of the segment magnet is shaped like a cone, the thickness of the magnetic pole conversion part is reduced, and an increase in cogging torque can be suppressed.
[0023]
In addition , when the laminated iron core is integrally formed, the caulking portion of the magnetic plate and the laser welding of the concave portion may be used in combination, and the polyhedron is not limited to a quadrangular shape, and similarly if it is an even polyhedron. Can be implemented.
[0024]
【The invention's effect】
As apparent from the above embodiment, according to the first aspect of the present invention, the segment magnet is attached with high accuracy by the action of the concave portion provided outside the caulking portion where the polyhedral magnetic plate is integrated by pack caulking. In addition, since the motor characteristics such as increase of cogging torque and occurrence of rotor unbalance are not adversely affected, a highly reliable rotor of the motor can be obtained.
[0025]
Further, it is possible to obtain an inexpensive segment magnet mosquito Maboko type, furthermore, since the cross-sectional shape of hog-backed shape thickness is thin at the converter of the pole, it can suppress an increase in cogging torque.
[0026]
Therefore, the segment magnet can be attached with high accuracy, and a highly reliable rotor for an electric motor that can suppress an increase in unbalance and cogging torque can be provided at low cost.
[Brief description of the drawings]
1 is a top view of a rotor in a reference embodiment of the present invention. FIG. 2 is a top view of a rotor in a first embodiment of the present invention. FIG. 3 is a top view of a conventional rotor.
11, 21 Rotating shaft 12, 22 Laminated iron core 13, 23 Segment magmet 14, 24 Protruding part 15 , 25 Caulking part 16, 26 Concave part

Claims (1)

In a rotor of an electric motor in which segment magnets are fixed to the surface of a laminated core obtained by punching and laminating a large number of magnetic plates, a plurality of protrusions that are polyhedral and have segment magnets arranged at equal intervals in the circumferential direction And a magnetic plate having a recess provided between the protrusions, and a segment magnet having a kamaboko-shaped cross section, and the recess is provided outside the caulking portion where the magnetic plate is integrated by pack caulking. An electric motor rotor.

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