JP3856958B2 - motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnet body and a motor using the magnet body.
[0002]
[Prior art]
As a rotor magnet body used for a motor such as a spindle motor, one made of a plastic magnet is widely used. This type of plastic magnet is formed by compression molding by mixing a magnet material (for example, cobalt, iron, etc.) with a rare earth metal (for example, samarium, neodymium, etc.) and a synthetic resin as a binder.
[0003]
[Problems to be solved by the invention]
The conventional magnet body is entirely formed of a magnet, and is easily chipped and cracked. Care must be taken during transport so that no chipping or the like occurs. Such chipping and cracking are more likely to occur as the magnet body becomes thinner, and in the recent trend toward thinner motors, it is desired to realize a magnet body with less chipping and cracking.
[0004]
Such chipping and cracking problems also exist in the case of an attracting magnet body in a spindle motor that rotates by magnetically attracting a recording medium, and it is desired to realize an attracting magnet body that is less prone to chipping and cracking. ing.
[0006]
The purpose of the present invention, the rotor magnet member is to provide a motor capable of improving the productivity in relation to the adsorption magnet body.
[0007]
[Means for Solving the Problems]
The present invention includes a stationary member, wherein a top surface portion I relatively rotatable der respect to the stationary member and the cup-shaped rotor and a cylindrical portion depending from the ceiling surface portion, of the cylindrical portion of the rotor In a motor including a ring-shaped rotor magnet body mounted on an inner peripheral surface and a stator disposed to face the rotor magnet body, the rotor magnet body includes a magnet body and one of the magnet bodies . It has a reinforcing member which is integrally molded on the end face, towards the reinforcing member to the top portion of said rotor, characterized that you have been mounted on the rotor.
[0008]
According to the present invention, since the rotor magnet body has the magnet body and the reinforcing member integrally formed with the magnet body, the reinforcing member prevents the magnet body from being broken or cracked. In particular, even if the rotor magnet body becomes thinner due to the thinner motor, chipping and cracking of the rotor magnet body can be reduced due to the presence of the reinforcing member .
[0009]
Further, the present invention includes a stationary member, wherein a top surface portion I relatively rotatable in Adair relative to the stationary member and the cup-shaped rotor and a cylindrical portion depending from the ceiling surface portion, of the rotor A rotor magnet mounted on the inner peripheral surface of the cylindrical portion, a stator disposed to face the rotor magnet, and rotated integrally with the rotor and mounted on the upper surface of the top surface portion of the rotor. and, in the motor and a ring-shaped suction magnet body for attracting the recording disk magnetically, the suction magnet body, possess a magnet body and a reinforcing member that is integrally formed on one end surface of the magnet body , toward the reinforcing member to the top portion of said rotor, characterized that you have been mounted on the rotor.
[0010]
According to the present invention, since the attracting magnet body has the magnet body and the reinforcing member integrally formed with the magnet body, the reinforcing body prevents the magnet body from being broken or cracked. In particular, even if the attracting magnet body is thinned due to the thinning of the motor, chipping and cracking of the attracting magnet body can be reduced due to the presence of the reinforcing member. The attracting magnet body can be provided directly on the rotor, or a turntable can be provided so as to rotate integrally with the rotor and can be attached to the turntable .
[0011]
Moreover, the present invention is characterized in that the reinforcing member is made of a magnetic material.
[0012]
According to the present invention, since the reinforcing member is formed of a magnetic material, it can function the reinforcing members rotor magnet member, a magnetic shield and / or the back yoke of the adsorbent magnet body.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, it will be described in more detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing a spindle motor for driving a hard disk as an example of a motor of the present invention having a magnet body according to the present invention, and FIG. 2 is a perspective view showing a rotor magnet body in the spindle motor of FIG. It is.
[0020]
Referring to FIG. 1, the illustrated motor includes a mounting bracket 2 as a stationary member and a rotor hub 4 as a rotor that is rotatable relative to the mounting bracket 2. The mounting bracket 2 has a circular bracket body 6, and a mounting flange 8 projecting radially outward is provided on the outer peripheral portion of the bracket body 6. The mounting bracket 2 is attached to a base member (not shown) of the hard disk drive device.
[0021]
One end (lower end) of the shaft member 10 is fixed to the mounting bracket 2 by, for example, press fitting, and the rotor hub 4 is rotatably supported by the shaft member 10 via a pair of bearings 12 and 14. The rotor hub 4 has a cup-shaped hub body 16, and the inner peripheral portion of the hub body 16 is supported via a pair of bearings 12 and 14. A disc mounting portion 18 is provided on the outer peripheral portion of the hub body 16. For example, a 2.5-inch hard disk 20 as a recording medium is mounted on the disk mounting portion 18, and the mounted disk 20 is attached to the hub body 16 by a mounting screw 22. Thus, the disc is placed between the disc mounting portion 18 and the disc mounting portion 18. The hub body 16 is further provided with a hanging portion 26 that extends below the disk mounting portion 18, and a rotor magnet body 28 is mounted on the inner peripheral surface of the hanging portion 26. The rotor magnet body 28 is fixed by, for example, an adhesive, and the detailed configuration thereof will be described in detail later. The hub body 16 is made of a magnetic material such as iron or stainless steel.
A stator 30 is disposed facing the magnet body 28. The stator 30 includes a stator core 32 formed by stacking core plates and a coil 34 wound around the stator core 32, and the stator core 32 is attached to an outer peripheral surface of an annular support wall 36 formed on the bracket body 6. Has been.
[0022]
In this spindle motor, a cap member 38 is disposed outside the upper bearing 14. The cap member 38 is attached to the inner peripheral portion of the hub body 16 so as to seal the outside of the bearing 14 and prevents the grease of the bearing 14 from scattering to the outside.
[0023]
Next, the illustrated rotor magnet body 28 will be described with reference to FIG. 2 together with FIG. The illustrated magnet body 28 includes a ring-shaped magnet main body 42 and a reinforcing member 44 formed integrally with the magnet main body 42. The ring-shaped magnet main body 28 is alternately magnetized with N and S poles in the circumferential direction. The magnet main body 42 includes a samarium-cobalt magnet (cobalt as a magnet material mixed with samarium as a rare earth metal and a synthetic resin as a binder), a neodymium-iron magnet (iron as a magnet material, as a rare earth metal). Of neodymium and a synthetic resin as a binder and a slight amount of boron).
[0024]
In such a magnet body 28, since the magnet body 42 is formed integrally with the reinforcing member 44, the presence of the reinforcing member 44 reduces the occurrence of chipping and cracking of the magnet body 42, and the handling thereof has been conventionally performed. It becomes easier than that. In this embodiment, the reinforcing member 44 is formed of a thin plate-like member, and is provided so as to cover substantially the entire end surface of the magnet body 42 (upper end surface in FIGS. 1 and 2). By providing the reinforcing member 44 in this manner, when the auxiliary member 44 is placed on the lower side and placed on, for example, a transport tray (not shown) or the like, the reinforcing member 44 comes into contact with the transport tray and the magnet main body 42 is transported. There is no contact. Therefore, it is possible to reliably prevent the occurrence of chipping, cracking, etc. during the conveyance of the magnet body 18.
[0025]
The reinforcing member 44 can be formed of a magnetic material such as iron or stainless steel, or a nonmagnetic material such as aluminum or synthetic resin. When formed from a magnetic material, the magnetic flux from the magnet main body 42 passes through the reinforcing member 44. The reinforcing member 44 also functions as a magnetic shield and / or a back yoke, and the dedicated magnetic shield and back yoke are omitted. be able to. For example, the reinforcing member 44 shown in FIGS. 1 and 2 can mainly have a function of a magnetic shield for the disk 20. Further, it also has a function as a spacer for adjusting the position of the magnet body 8 with respect to the stator 30.
[0026]
The magnet body 18 having such a configuration has a particularly thin overall thickness (height), for example, the magnet body 42 has a thickness (height) a of about 1.5 mm and a thickness b of 1. This is effective when the thickness of the reinforcing member 44 is about 3 mm and the thickness c is about 0.2 to 0.3 mm. The thin magnet body 18 can be prevented from chipping and cracking to improve productivity. it can.
[0027]
Such a magnet body 18 is formed by, for example, compression molding known per se. That is, the reinforcing member 44 is inserted into the mold recess of the lower mold, the lower mold is heated, and the mold recess is filled with a mixed magnet material in which a magnet material, a rare earth metal, and a binder are mixed. Compress the mixed magnet material. Thereafter, through a heat treatment step, the mixed magnet material in the mold recess is heated and compressed to be integrated with the reinforcing member 44, and the above-described magnet body 18 is integrally formed.
[0028]
FIG. 3 is a partial sectional view showing a part of a second embodiment of a spindle motor provided with a magnet body according to the present invention. In the second embodiment, the magnet body is modified. In the following embodiments, substantially the same members as those in the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted.
[0029]
With reference to FIG. 3, in this magnet body 62, an annular recess 66 is formed in most part of the ring-shaped magnet main body 64 except for an inner peripheral portion at one end (upper end in FIG. 3). The reinforcing member 68 is provided by integral molding. Such a magnet body 62 is also formed by compression molding, for example. The other configuration of the motor shown in FIG. 3 is substantially the same as the configuration shown in FIG.
[0030]
When this magnet body 62 is used, the auxiliary member 68 is provided integrally with the magnet body 64, so that the magnet body 64 can be reduced in chipping and cracking. As understood from FIG. 3, the reinforcing member 68 is not exposed on the inner peripheral surface of the magnet body 62, and the inner peripheral portion of the magnet body 64 faces the stator 30. The acting magnetic force can be increased. Further, the reinforcing member 68 functions as a magnetic shield and a back yoke .
[0034]
In the embodiment described above, the magnet body according to the present invention has been described as applied to the rotor magnet body. FIG. 4 is a sectional view showing still another embodiment of a spindle motor as an example of a motor of the present invention provided with a magnet body according to the present invention.
[0035]
Referring to FIG. 4 , the illustrated motor includes a stationary member 102 and a rotor 104 that is rotatable relative to the stationary member 102. The stationary member 102 includes a base member 106 and an annular support member 108 provided on the inner peripheral portion of the base portion 106. The rotor 104 includes a cup-shaped rotor main body 110, a rotation support member 112 provided on the inner peripheral portion of the rotor main body 110, and a rotation shaft 114 fixed to the rotation support member 112.
[0036]
The rotor 104 is rotatably supported by the stationary member 102 via a ball bearing 116 and a sleeve bearing 118. That is, the ball bearing 116 is interposed between the annular support member 108 and the rotation shaft 114, and the sleeve bearing 118 is interposed between the annular support member 108 and the rotation support member 112.
[0037]
The rotor body 110 includes an annular peripheral side wall 120 and an end wall 122 provided at one end of the peripheral side wall 120, and an annular rotor magnet body 124 is provided on the inner peripheral surface of the peripheral side wall 120. The magnet 124 is, overall it is formed from the magnet body, instead of this, the embodiment shown in FIGS. 1 and 2, it is also possible to use a form state shown in FIG.
[0038]
A stator 126 is disposed facing the rotor magnet body 124. The stator 126 includes a stator core 128 attached to the outer peripheral surface of the annular support member 108 and a coil 130 wound around the stator core 128.
[0039]
In this embodiment, the inner peripheral portion of the end wall 122 of the rotor body 110 is provided with an annular mounting recess 132 by deforming the inner peripheral portion toward the annular support member 108, and a recording medium is stored in the mounting recess 132. An attracting magnet body 134 for magnetically attracting is mounted. The attracting magnet body 134 is fixed by, for example, an adhesive.
[0040]
The illustrated attracting magnet body 134 includes a thin ring-shaped magnet main body 136 and a reinforcing member 138 integrally formed with the magnet main body 136, and the reinforcing member 138 is provided on the lower surface of the magnet main body 134. The magnet main body 136 is formed of, for example, the same magnet as described above, and N poles and S poles are alternately magnetized in the circumferential direction.
[0041]
In such an attracting magnet body 134, the magnet main body 136 is formed integrally with the reinforcing member 138. Therefore, the presence of the reinforcing member 138 can reduce the occurrence of chipping and cracking of the magnet main body 136. In this embodiment, the reinforcing member 138 is formed of a thin plate-like member and is provided so as to cover substantially the entire lower surface of the magnet body 136. Therefore, by placing the reinforcing member 138 on the lower side, for example, on a transport tray (not shown) or the like, the reinforcing member 138 comes into contact with the transport tray, and chipping or cracking during the transport of the magnet body 134 may occur. Can be prevented. Further, the reinforcing member 138 can be made of a magnetic material to function as a back yoke.
In this embodiment, the description is applied to the motor in which the attracting magnet 134 is directly provided on the rotor body 110. However, the present invention is not limited to this, and the turn on which the recording medium is placed on the rotating shaft (or the rotor body) The present invention can be similarly applied to a configuration in which a table is provided. In such a case, the attracting magnet body is attached to the housing recess formed in the turntable.
[0042]
The embodiments of the magnet body according to the present invention and the motor according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications and corrections can be made without departing from the scope of the present invention. .
[0043]
For example, the reinforcing member can be made of a nonmagnetic material such as aluminum when the function as the magnetic shield and / or the back yoke is not necessarily required.
[0044]
Further, for example, in the illustrated embodiment, the reinforcing member has a planar shape, but can be formed in a substantially L shape extending from the end surface of the magnet body to the peripheral side surface.
[0046]
【The invention's effect】
According to the motor of the first aspect of the present invention , the reinforcing member is integrally formed with the magnet body of the rotor magnet body, so that the rotor magnet body is prevented from being chipped or cracked .
[0047]
According to the motor of the second aspect of the present invention , since the reinforcing member is integrally formed with the magnet body of the attracting magnet body, the attracting magnet body is prevented from being chipped or cracked .
[0048]
Further, according to the motor according to claim 3 of the present invention, the rotor magnet body reinforcing member, Ru can function as a magnetic shield and / or the back yoke of the adsorbent magnet body.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a spindle motor as an example of a motor of the present invention.
2 is a perspective view showing a rotor magnet body in the spindle motor of FIG. 1. FIG.
FIG. 3 is a partial cross-sectional view showing a part of a second embodiment of a spindle motor as an example of a motor of the present invention.
FIG. 4 is a partial cross-sectional view showing still another embodiment of a spindle motor as an example of the motor of the present invention.
[Explanation of symbols]
2, 102 stationary member 4 rotor hub 10 shaft member 16 the hub body 28,6 2 B over data magnet body 30,126 stator 42, 64, 1 36 magnet body 44, 68, 1 38 reinforcing member 104 rotor 110 rotor body 134 adsorbent magnet body

Claims (3)

A stationary member, wherein a top surface portion I relatively rotatable der respect to the stationary member and the cup-shaped rotor and a cylindrical portion depending from the ceiling surface, the inner peripheral surface of the cylindrical portion of the rotor In a motor comprising a mounted ring-shaped rotor magnet body, and a stator disposed facing the rotor magnet body,
The rotor magnet body, and the magnet body, have a reinforcing member which is integrally formed on one end surface of the magnet body, toward the reinforcing member to the top portion side of the rotor, that is mounted on the rotor A motor characterized by that. A stationary member, wherein a top surface portion I relatively rotatable in Adair relative to the stationary member and the cup-shaped rotor and a cylindrical portion depending from the top surface, an inner periphery of the cylindrical portion of the rotor A rotor magnet mounted on the surface , a stator disposed opposite to the rotor magnet , a recording disk mounted on the top surface of the top surface of the rotor and rotating integrally with the rotor. Motor equipped with a ring-shaped attracting magnet body that attracts automatically,
The suction magnet body, and the magnet body, have a reinforcing member which is integrally formed on one end surface of the magnet body, toward the reinforcing member to the top portion side of the rotor, that is mounted on the rotor A motor characterized by that.   3. The motor according to claim 1, wherein the reinforcing member is made of a magnetic material.

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