JP4716609B2 - Manufacturing method of motor parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a motor component.
[0002]
[Prior art]
Conventionally, in a motor such as a spindle motor provided with a rotor hub that rotates while holding a rotating body such as a magnetic disk, an annular magnet fixed to the rotor hub with an adhesive is used as a rotation drive member for rotating the rotor hub. What is comprised from the stator which wound the coil which electromagnetically interacts between annular magnets is used. When the annular magnet is fixed to the rotor hub with an adhesive, the adhesive is heat-treated and hardened. The heat treatment irreversibly demagnetizes the annular magnet.
[0003]
Therefore, conventionally, as a method of fixing an annular magnet to a rotor hub without an irreversible demagnetization by heat treatment, an unmagnetized annular magnet is attached to the rotor hub with an adhesive, and this is heat-treated. Then, after the adhesive is cured, a method of magnetizing the annular magnet is known. Hereinafter, a method for manufacturing the motor component will be described with reference to FIG.
[0004]
FIG. 2 is an explanatory view showing a method of manufacturing the conventional motor component.
In FIG. 2, first, an adhesive is applied to the outer peripheral surface of the unmagnetized annular magnet 1, and this is inserted into the rotor hub 2 in which the cylindrical bearing support portion 4 is formed. It attaches to the predetermined part of this through the back yoke 3. Next, the rotor hub 2 is accommodated in the heating furnace 5 and heat-treated at a high temperature. This heat treatment cures the adhesive, releases the gas generated with the curing of the adhesive, and removes volatile components contained in the adhesive as gas. After the heat treatment, the rotor hub 2 is inserted so that the inner peripheral surface of the annular magnet 1 faces the magnetizing yoke 7 of the magnetizing device 6, and the annular magnet 1 is magnetized.
[0005]
[Problems to be solved by the invention]
However, since the annular magnet 1 is magnetized after the non-magnetized annular magnet 1 is fixed to the rotor hub 2 in the manufacturing method as described above, demagnetization due to heat treatment is avoided, but the magnetizing device 6 has a problem that the internal shape of the rotor hub 2 is remarkably limited depending on the shape of the magnetized yoke 7. For example, if the magnetized yoke 7 formed in a solid shape such as a column is inserted into the rotor hub 2 in which the cylindrical bearing support portion 4 is formed and the annular magnet 1 is to be magnetized, the magnetized yoke 7 is In some cases, the cylindrical bearing support portion 4 cannot be inserted to an appropriate position by contacting the end surface.
[0006]
In addition, when a pre-magnetized annular magnet is attached to the rotor hub with an adhesive and then heat-treated to cure the adhesive, a general property of magnets is that irreversibly demagnetizing when the magnetized magnet is heated. Therefore, it is necessary to use an expensive magnet using a material with high density and strong magnetic force, such as Neom No. 12, and to have a magnetic force in anticipation of demagnetization, which inevitably increases the product cost. There is a problem of being.
[0007]
Accordingly, the present invention solves the above-described problems, and can magnetize the annular magnet without being restricted by the shape of the rotor hub, and suppress the amount of demagnetization of the annular magnet at a low cost. It is an object of the present invention to provide a method of manufacturing a motor component that can be used.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems, a method of manufacturing a motor component according to the present invention includes rotating a rotor hub by electromagnetic interaction between a rotor hub formed in a cylindrical shape , a stator wound with a coil, and the stator . an annular magnet for a motor component manufacturing method for manufacturing a motor component which holds and rotates the driven rotating body, said annular magnetized the annular magnet unpolarized state, magnetized attached by adhesive magnet to the inner circumferential surface of the rotor hub, the axial direction of the long annular magnetic body than said annular magnet length, the inner peripheral surface facing vital said annular magnet with a predetermined interval between the annular magnet so as to protrude from both axial ends of the insert into the rotor hub with an attached ring magnet, and heat treating the rotor hub inserting the annular magnetic body Characterized by securing the annular magnet to the rotor hub by curing the adhesive.
[0009]
According to the above configuration, since the annular magnetic body is inserted into the rotor hub so as to face the annular magnet and heat treatment is performed, a magnetic circuit is formed between the annular magnetic body and the annular magnet, and the annular magnet is formed during the heat treatment. However, the permeance is kept high under the influence of the magnetic force of the annular magnetic body, and the irreversible demagnetizing action hardly occurs. As a result, the amount of demagnetization of the annular magnet can be significantly suppressed as compared with the conventional method. Further, since the annular magnet is magnetized before being fixed to the rotor hub, the annular magnet can be magnetized without being restricted by the shape of the rotor hub. In addition, since the amount of demagnetization of the annular magnet can be significantly suppressed, it is not necessary to use a magnet material having a high density and a strong magnetic force, and a motor component can be obtained at a low cost.
[0012]
Furthermore, the present invention is characterized in that, in the above configuration, the heat treatment is performed at a temperature of 60 to 80 ° C. According to the above configuration, the heat treatment temperature is appropriate and the amount of demagnetization of the annular magnet is suppressed, while the adhesive is cured, the gas generated as the adhesive is cured, and the volatile components contained in the adhesive Can be reliably removed.
[0013]
When the heat treatment temperature is less than 60 ° C, it takes a long time to cure the adhesive, release the generated gas, and remove the volatile components, which may reduce the production efficiency. It is remarkable. On the other hand, when the heat treatment temperature exceeds 80 ° C., the amount of demagnetization of the annular magnet tends to increase.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a method of manufacturing a motor component according to the present invention will be described with reference to FIG.
[0015]
The same components as those in FIG. 2 showing the conventional example will be described with the same reference numerals.
FIG. 1 is an explanatory view showing a method of manufacturing a motor component in the embodiment of the present invention.
[0016]
In FIG. 1, first, an unmagnetized annular magnet 1 having a predetermined dimension is prepared. The magnetized yoke 7 of the magnetizing device 6 is inserted into the annular magnet 1, and the magnetized device 6 magnetizes the annular magnet 1 to a predetermined magnetic force.
[0017]
Next, a thermosetting adhesive is applied to the outer peripheral surface of the magnetized annular magnet 1. Then, the annular magnet 1 coated with the adhesive is inserted into the rotor hub 2.
The rotor hub 2 is formed in a cylindrical shape and is configured to hold a rotating body such as a magnetic disk on its outer peripheral surface, and a cylindrical bearing support portion 4 for mounting a bearing device is formed in the rotor hub 2. Further, a back yoke 3 is mounted on the inner wall of the rotor hub 2.
[0018]
The annular magnet 1 inserted into the rotor hub 2 is attached to a predetermined portion of the inner peripheral surface of the back yoke 3 with an adhesive. That is, the annular magnet 1 is attached to the inner peripheral surface of the rotor hub 2 via the back yoke 3.
[0019]
Next, in order to suppress the amount of demagnetization of the annular magnet 1 when the adhesive is cured by heat treatment, an annular magnetic body formed so that the axial length is longer than the axial length of the annular magnet 1. 8 is inserted into the rotor hub 2 so as to face the inner peripheral surface of the annular magnet 1 with a predetermined distance and to protrude from both axial ends of the annular magnet 1.
[0020]
And the rotor hub 2 in which the annular magnetic body 8 was inserted is accommodated in the heating furnace 5, and is heat-treated at a predetermined temperature between 60 to 80 ° C. to cure the adhesive. The annular magnetic body 8 is removed from the rotor hub 2 after the heat treatment.
[0021]
As a result, a motor component is obtained in which the annular magnet 1 is fixed to the inner peripheral surface of the rotor hub 2 with a cured adhesive.
Thereafter, a stator 9 wound with a coil for rotating the rotor hub 2 by electromagnetic interaction with the annular magnet 1 is mounted in the rotor hub 2 so as to face the annular magnet 1 and a bearing device (not shown) is provided. The motor is completed by being incorporated in the bearing support 4 and further attaching necessary parts.
[0022]
According to the above configuration, since the annular magnetic body 8 is inserted into the rotor hub 2 so as to face the inner peripheral surface of the annular magnet 1 and protrude from both axial end portions of the annular magnet 1, heat treatment is performed. A wide magnetic circuit longer than the axial length of the annular magnet 1 is formed between the annular magnet 1 and the annular magnet 1, and the permeance of the annular magnet 1 during the heat treatment is kept high. Magnetic quantity can be greatly suppressed. Furthermore, since the adhesive is cured by heat treatment at a predetermined temperature between 60 to 80 ° C., the adhesive can be cured in a short time while suppressing the amount of demagnetization of the annular magnet 1, and the adhesive It is possible to reliably release the gas generated during the curing and remove the volatile components contained in the adhesive.
[0023]
In the present embodiment, the annular magnet 1 is fixed to the inner peripheral surface of the rotor hub 2 via the back yoke 3, but may be directly fixed to the inner peripheral surface of the rotor hub 2 without using the back yoke 3.
[0024]
In this embodiment, the annular magnet 1 is fixed to the inner peripheral surface of the rotor hub 2, but the annular magnet 1 may be fixed to the outer peripheral surface of the rotor hub 2. In this case, the annular magnetic body 8 inserted into the rotor hub 2 during the heat treatment faces the annular magnet 1 through the rotor hub 2.
[0025]
【The invention's effect】
As described above, according to the motor component manufacturing method of the present invention, the amount of demagnetization of the annular magnet can be significantly suppressed. Further, the annular magnet can be magnetized without being restricted by the shape of the rotor hub, and a motor component can be obtained at a low cost.
[0026]
Furthermore , while suppressing the amount of demagnetization of the annular magnet, it is possible to reliably perform the curing of the adhesive, the release of gas generated with the curing of the adhesive, and the removal of volatile components contained in the adhesive.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a method of manufacturing a motor component in an embodiment of the present invention.
FIG. 2 is an explanatory view showing a conventional method of manufacturing a motor component.
[Explanation of symbols]
Reference Signs List 1 annular magnet 2 rotor hub 3 back yoke 4 bearing support 5 heating furnace 6 magnetizing device 7 magnetizing yoke 8 annular magnetic body 9 stator

Claims (2)

A rotor hub which is formed into a cylindrical shape, and rotates while holding a stator wound with a coil, a and an annular magnet driven rotating body for rotating the rotor hub by electromagnetic interaction with the stator A motor part manufacturing method for manufacturing a motor part ,
Magnetizing the annular magnet in an unmagnetized state ,
The annular magnet magnetized attached by adhesive to the inner peripheral surface of the rotor hub,
Axial length of a long annular magnetic body than said annular magnet, so as to protrude from the axial ends of opposing vital said annular magnet while keeping the internal circumferential surface a predetermined distance of the ring magnet, the ring magnet the insert into the rotor hub attached,
A method for manufacturing a motor component, comprising: fixing the annular magnet to the rotor hub by heating the rotor hub into which the annular magnetic body is inserted to cure the adhesive. The method of manufacturing a motor component according to claim 1, wherein the heat treatment is performed at a temperature of 60 to 80 ° C.

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