JP2660745B2 - Spindle motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor, and more particularly to a spindle motor for a disk.

[Conventional technology]

Generally, for finishing the outer portion of a hub of a small-sized spindle motor, after completion of assembly as a spindle motor, the motor itself is rotated to perform cutting or grinding.

[Problems to be solved by the invention]

In recent years, with miniaturization of magnetic disks, optical disks, and the like, spindle motors for driving them have been further miniaturized. For this reason, the rotational driving torque of the motor itself is insufficient, and particularly in a motor using a hard-to-cut material such as stainless steel for the hub, finishing the outer flange portion of the hub has become extremely difficult.

[Means for solving the problem]

In order to solve such a problem, the present invention provides a method of fixing a hub body made of a steel material and a good cutting material fixed to an outer flange portion at one end outer peripheral edge of the hub body from the inside in the axial direction. A flange portion, and a ring body for detachable outer flange attached to the outer peripheral edge side of the other end of the hub body is made of the same material and the same cross-sectional shape as the fixed outer flange portion, and substantially in the axial center of the hub. With respect to a plane, the fixed outer flange portion and the detachable outer flange ring body are symmetrical, and the fixed outer flange portion, the magnetic disk and the spacer, and the detachable outer flange ring body are connected to the other end of the hub body. From the side to one end side, the hub body is successively externally fitted to the hub body to form a laminate, and a disk fixing clamp made of the same material as the hub body is attached to and detached from the other end side of the hub body. Attach freely Holding the laminate sandwiched form between the outer flange portion of the disc fixing clamp and the hub body.

(Operation)

Even with the rotation torque of the motor itself after the assembly is completed, if the fixed outer flange portion is made of a good cutting material of the hub, the finishing can be easily and accurately performed.

With respect to the substantially central plane in the axial direction of the hub, the fixed outer flange and the ring member for the detachable outer flange are symmetrical, so that the motor becomes well-balanced and partially In addition, uneven expansion can be prevented, and adverse effects such as thermal shift can be eliminated.

Since the hub body and the disk fixing clamp are made of the same material, there is no difference in thermal expansion between the hub body and the disk fixing clamp, and the clamp does not distort with respect to the hub body.

In addition, a fixed outer flange portion, a magnetic disk and a spacer, and as a detachable outer flange ring body, a laminated body is sequentially formed as an external fitting from the other end side toward one end side, and
Since the disk fixing clamp may be attached to the other end of the hub body, the assembling work is easy.

〔Example〕

 Hereinafter, the illustrated embodiment will be described.

1 and 2, reference numeral 1 denotes a bracket, which comprises a flange portion 2 and a cylindrical portion 3, in which a rotating shaft 5 is pivotally supported via a pair of bearings 4,4. The hub 6 is fixed to one end of the rotating shaft 5. Reference numeral 7 denotes a stator which is fixed to the outer peripheral surface of the cylindrical portion 3.

The hub 6 has a bottomed bowl shape including a flat portion 8 and a cylindrical portion 9, and surrounds the stator 7 and the cylindrical portion 3. Reference numeral 30 denotes a rotor magnet which is fixed to the inner peripheral surface of the hub 6 and faces the stator 7 with a predetermined minute gap.

The hub 6 has a hub body 10 made of a steel material such as stainless steel or other steel, and an aluminum or other light body which is locked from the inside in the axial direction to an outer flange portion at one outer peripheral edge of the hub body 10. And a fixed outer flange portion 11 of a good cutting material such as an alloy or a steel-based metal. In other words, hub body 10
Has an annular notch 12 near the outer periphery of the upper surface of the plane portion 8 (upper part in the figure), and a small circumferential ridge 13 serving as the outer flange part on the outer periphery of one end (lower part in the figure). It has a flange shape. The fixed outer flange portion 11 has a rectangular shape having a cutout portion 14 having the same shape as that of the small-peripheral ridge 13 in a cross section, and the hub main body 10 is formed in the cutout portion 14 of the fixed outer flange portion 11. The fixed outer flange portion 11 is fitted into the small-circle convex shape 13 and integrally fixed by shrink fitting or press-fitting so that the fixed outer flange portion 11 is attached to one end surface of the fixed outer flange portion 11 with the magnetic disk 15. Receive.

Reference numeral 16 denotes a disk fixing clamp, which is a hub 6.
And the annular cutout 12 of the hub body 10
And is removably fixed by a fixing tool 17 such as a screw. Reference numeral 18 denotes a ring body for the detachable outer flange attached to the outer peripheral edge of the clamp 16, and the material of the ring body 18 is the same as that of the outer flange portion 11 and has the same sectional shape. That is, as is apparent from the drawing, the clamp 16 is provided with a small circumferential ridge 19 having the same cross-sectional shape as the small circumferential ridge 13, and
With a slightly projecting strip from the outer peripheral surface of 10, a ring body
The notch 18 is formed with a notch 20 to be fitted into the small circumferential ridge 19.

Thus, when assembling this spindle motor, the fixed outer flange portion 11, the magnetic disk 15, and the spacers 21 ...
Then, the detachable outer flange ring body 18 is sequentially mounted on the hub main body 10 from the other end side to the one end side of the hub main body 10 to form a laminate. Then, the disk fixing clamp 16 is detachably attached to the other end of the hub body 10.

That is, the laminated body is composed of the disc fixing clamp 16 and the hub body.
It is held in a clamped shape with the ten outer flanges. Magnetic disk 15…
Is held by the outer flange portion 11 and the ring body 18 from both end surfaces in a clamping manner, and the fixed outer flange portion is fixed with respect to the substantially central plane P in the axial direction of the hub 6 (see FIG. 2). The 11 and the detachable outer flange ring 18 have a symmetrical shape not only in terms of shape but also in terms of arrangement of different materials.

After the outer flange portion 11 is fixedly integrated with the hub body 10 by shrink-fitting or press-fitting, and after completion of assembly as a motor, a current is actually passed through the stator 7 to rotate, and the rotation torque is used. Then, the surface Q of the outer flange portion 11 particularly corresponding to the magnetic disk is finished by grinding or cutting. Conventionally, finishing of this part is extremely difficult when the entire hub is made of a difficult-to-cut material such as stainless steel, and dimensional accuracy and surface finish tolerance have not been sufficiently obtained. Since the portion 11 is a good cut of aluminum or the like, sufficient dimensional accuracy and a good finished surface can be obtained. Then, the magnetic disks 15 and the spacers 21 shown in FIG.
It is also preferable that the outer flange portion 11 and the ring body 18 are made of the same material or the same thermal expansion material.

As in the illustrated embodiment, the arrangement and the shape of the different materials are made symmetrical with respect to the substantially central plane P in the axial direction of the hub 6, so that the temperature increases when the motor is used. To prevent partial uneven expansion,
A thermal shift such as a deflection of the surface of the magnetic disks 15 can be effectively prevented.

The present invention can be freely changed in design other than the illustrated embodiment,
Other types of motors can be applied as long as the spindle motor has a rotating hub.For example, when the motor shaft is fixed, or when the rotor magnet or stator is mounted inside the hub. And a type having a driving unit outside may be used.

〔The invention's effect〕

Since the present invention is configured as described above, the following effects can be obtained.

The hub body 10 made of a steel material is
The function of the back yoke described above is not required, and a separate magnetic body is not required between the hub and the rotor magnet, so that the motor can be simplified and downsized.

Since the fixed outer flange portion 11 which receives one end surface of the magnetic disks 15 in a contact state is a good cutting material, the finishing process can be performed sufficiently smoothly and with high precision even with the driving torque of the motor after the assembly is completed.

Since the disk fixing clamp 16 is not distorted with respect to the hub body 10 due to thermal expansion, the mounting state of the clamp 16 is not deformed and does not adversely affect the detachable outer flange ring body 18,
The disc 15 to be mounted does not tilt.

With respect to the substantially central plane P in the axial direction of the hub 6, the fixed outer flange portion 11 and the detachable outer flange ring member 18 have a symmetrical shape, so that the motor becomes well-balanced and the temperature increases when the motor is used. Along with this, it is possible to prevent partial non-uniform expansion from occurring, and it is possible to effectively prevent a thermal shift such as a touch of the surface of the magnetic disks 15.

Fixed outer flange part 11 and removable outer flange ring body 18
Are made of the same material and have the same cross-sectional shape, the components of the fixed outer flange portion 11 and the removable outer flange ring 18 can be shared, and the motor can be easily manufactured.

The fixed outer flange portion 11, the magnetic disks 15 and the spacers 21 and the detachable outer flange ring 18 are sequentially fitted from the other end toward the one end, and the disk fixing clamp 16 is Since it is sufficient to attach the hub body 10 to the other end, the assembly can be performed easily and reliably.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, and FIG. 2 is an explanatory view thereof. 6 ... hub, 10 ... hub body, 11 ... outer flange part, 16
…… Clamp, 18 …… Ring body.

Claims (1)

(57) [Claims] 1. A hub 6 comprising: a hub body 10 made of a steel material;
And a fixed outer flange portion 11 of a good cutting material that is locked from the inside in the axial direction to an outer flange portion at one end outer peripheral edge of the hub body 10, and further attached to the outer peripheral edge side of the other end of the hub body 10. The detachable outer flange ring member 18 is made of the same material and has the same cross-sectional shape as the fixed outer flange portion 11, and the fixed outer flange portion 11 and the detachable outer flange ring member 18 are connected with respect to the substantially central plane P in the axial direction of the hub 6. It is symmetrical, and the fixed outer flange portion 11, the magnetic disk 15 and the spacer 21 are formed.
And the ring body 18 for the detachable outer flange, the hub body 10
The hub body 10 is successively externally fitted from the other end side to the one end side.
And a disc fixing clamp 16 made of the same material as that of the hub main body 10.
A spindle motor which is detachably attached to the other end of the spindle motor and the disc fixing clamp 16 and the outer flange portion of the hub body 10 hold the laminated body in a sandwiched state.