JP3316360B2 - Rotary table drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary table driving device such as an optical disk driver, and more particularly to an integrated structure of a rotary table and a spindle motor.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, a rotary table driving device such as a compact disk (CD) player is made of brass fixed to a rotor shaft 1a of a spindle motor (brushless motor) 1 on a player body side. The rotary table 2, an annular permanent magnet 3 for clamping and clamping which is fitted and fixed in an annular groove 2 b around a boss portion 2 a of the rotary table 2, and a disk hole 4 a fitted in a hub 2 c to form the rotary table 2 The disk medium 4 to be placed on the disk non-slip layer 2d, and the disk medium 4 is pressed down by the magnetic attractive force of the built-in iron disk (yoke) 5a and the clamp permanent magnet 3 in accordance with the disk medium 4. And a disk presser 5. The ring-shaped permanent magnet for clamping attraction 3 is obtained by plating the surface of the ring-shaped magnet with metal, and is fixed with an adhesive applied in the ring-shaped groove 2b.

The spindle motor 1 includes a printed wiring board (attachment base plate) 1b attached to a chassis (not shown) on the player body side, and a cylindrical core retainer (bearing housing) 1c which is fixed by caulking to the printed wiring board. And the core presser 1c
And a laminated core 1d integrally assembled with
d, a sinter bearing (bearing metal) 1f fitted in the core retainer 1c, and a rotor shaft 1a supported by the sinter bearing 1f and fixed to the rotor shaft 1a via a brass spacer 1g. It has an inverted cup-shaped iron rotor case 1h and a rotor magnet 1i bonded and fixed to the inner peripheral surface of the rotor case 1h. 1j is a receiving plate (thrust plate) for receiving the lower end of the rotor shaft 1a, 1k is a Hall element, and 1m is a flexible wiring board.

As shown in FIG. 7A, the rotor-side assembly of the spindle motor 1 integrates the rotor shaft 1a into the shaft hole of the brass spacer 1g by press-fitting, as shown in FIG. 7B. A spacer 1g is accommodated in a press drawing hole of an iron rotor case 1h and fixed by caulking. Thereafter, the rotor shaft 1a of the rotor-side assembly 10 of the spindle motor 1 shown in FIG. 7B is pressed into the shaft hole of the rotary table 2 shown in FIG.
The rotor-side assembly 20 with a rotary table shown in FIG. By inserting the rotor shaft 1a of the rotor-side assembly 20 with the rotary table into the sinter bearing 1f of the stator-side assembly shown in FIG. 6, a rotary table driving device is manufactured.

[0005]

However, the above rotary table driving device has the following problems.

The method of fixing the rotor shaft 1a of the spindle motor 1 and the rotor case 1h is as follows. First, the rotor shaft 1a is press-fitted into a brass spacer 1g for caulking, and then the brass spacer 1g is attached to the rotor case 1h. The spacer 1g is accommodated in the press drawing hole and fixed by caulking. The intermediate part of the brass spacer 1g for caulking is required, and the rotor shaft 1a and the rotor
The degree of perpendicularity to the case 1h is likely to vary, causing a problem in the gap between the rotor and the stator and adversely affecting the motor performance, leading to a reduction in yield.

Further, when the rotor shaft 1a is press-fitted into the shaft hole of the rotary table 2 and integrated therewith, the rotary table 2 must be a cut product made of brass, which necessitates a high manufacturing cost. Even if there is a slight error in the verticality between the rotary table 2 and the rotor shaft 1a after press-fitting,
In order to cause vibration failure due to surface runout of the disk medium, press-fitting accuracy has been increasingly demanded under recent demands for higher rotational speed, which has been a factor of lowering the yield.

In view of the above problems, an object of the present invention is to integrate a rotor side of a spindle motor and a rotary table as an insert molded product, thereby significantly reducing the number of manufacturing steps, and improving the manufacturing efficiency. It is an object of the present invention to provide a rotary table driving device capable of easily improving the verticality between a rotor case and the vertical between a rotor shaft and a rotary table to improve the yield.

[0009]

In order to solve the above-mentioned problems, the present invention provides a rotary table driving apparatus having a spindle motor for driving a rotary table on which a disk medium is to be mounted. The table is a resin molded portion formed by resin molding by inserting the rotor shaft of the spindle motor and the end surface of the rotor case, and the rotor shaft and the rotor case are respectively formed around the indented molding resin. has a stop portion, the detent portion of the rotor case, the table from the end face
Cut-and-raised piece that is cut and raised on the side and buried in the resin molded part
And a front surface side resin layer and an end surface portion of the end surface portion in the resin forming portion
As a resin flow passage connecting the backside resin layer of
And an opening .

Here, it is preferable that the detent part of the rotor shaft is a knurled part. Further, the rotary table may have a two-color resin molding structure including a table body of a first-color resin molding portion and a disk anti-slip layer of a second-color resin molding portion laminated on the table body. . Further, it is preferable that a boundary between the table main body and the disk anti-slip layer is an uneven rough surface. A part of the rotor case may be used also as a back yoke of the attraction permanent magnet for clamping.

[Operation] As described above, since the rotor side of the spindle motor and the rotary table are integrally formed as an insert molded product, the caulking between the rotor shaft, the rotor case and the rotary table can be prevented. Eliminates the need for press fit and secures, greatly reducing the number of manufacturing processes without using costly parts and intermediate parts, as well as the perpendicularity between the rotor shaft and the rotor case and the perpendicularity between the shaft and the rotary table. Can also achieve higher precision. As a result, the yield can be improved, and the cost of the apparatus can be reduced. In addition, the space formed between the rotor case and the rotary table can be eliminated by integration by insert molding, so that the rotary table driving device can be made thinner and the air resistance can be reduced. In particular, the detent part of the rotor case
Is cut and raised from the end face to the front side and embedded in the resin molding.
The cut-and-raised piece that is submerged and the end face of the resin forming part
Resin that connects the front side resin layer and the back side resin layer at the end face
It has a cut-and-raised opening as a flow passage,
When forming the rotor case, insert
Since the opening can be formed at the same time, the cost can be reduced.
And the end face of the rotor case during resin molding.
Using the part as a core material to improve the strength and reduce the thickness of the rotary table
Not only can it be
In addition to the anchoring effect, resin flow through the cut and raised opening
The front side resin layer and the back side resin layer of the resin molded part
It is firmly stopped because it is in linkage and close contact with the end face
Function can be demonstrated and high reliability can be achieved .

Here, since the rotor shaft and the rotor case have a detent part in which the resin is depressed, the anchoring effect is exhibited by the detent part in which the resin is depressed, and the rotor shaft and the rotor case have a detent.
Play is less likely to occur between the shaft or rotor case and the resin molded part.

As the detent part of the rotor case, an uneven surface, an opening or a cut-and-raised opening part can be used. As the detent part of the rotor shaft, a deformed shaft and a D-shaped cut end of the shaft are used. , A surface roughened on the tip end side of the shaft to about 50 μm or more, a shaft having a through hole formed in the peripheral surface of the shaft, and the like.

At the tip of the D-shaped cut, voids often remain in the D-shaped cut during resin molding, which may cause looseness. Also, the unit price of the shaft having the through hole is high. Therefore, in the present invention, a knurled marking portion is used as a detent portion of the rotor shaft, and in particular, a flat knurled marking portion is used. No void remains, and the cost of the rotor shaft can be reduced. Further, the molding portion of the rotary table has a two-color resin molding structure including a table body of the first-color resin molding portion and a disk anti-slip layer of the second-color resin molding portion laminated on the table body. In contrast to the conventional method of forming the disk anti-slip layer which is a coating method, in the present invention,
Since the disk anti-slip layer can be continuously formed immediately after the molding of the table main body, the number of steps and cost can be further reduced.

The molding resin of the table body is a hard resin, and the molding resin of the disk anti-slip layer requires a rubber-like resin. However, in the present invention, the boundary is formed as a rough surface, so that the rubber-like resin is not used. It can be firmly attached to the surface of the hard resin, and peeling or the like can be eliminated.

Since the molded article has the rotor case inserted therein, the end of the rotor case can be used as an aggregate of the resin portion of the rotary table. It can also be used as a back yoke for a permanent magnet. Due to this dual purpose, a dedicated part of the back yoke can be eliminated, and the cost can be further reduced.

[0017]

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

[0019]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a front view with a partial cross section showing a rotor side assembly with a rotary table of a rotary table driving device according to a first embodiment of the present invention.

The rotary table driving device of this embodiment comprises a stator-side assembly of the spindle motor 1 shown in FIG. 6 and a rotor-side assembly with a rotary table shown in FIG. As shown in FIG. 6, the stator-side assembly of the spindle motor 1 includes a printed wiring board (attachment base plate) 1b attached to a chassis (not shown) on the player body side.
A cylindrical core retainer (bearing housing) 1c which is fixed by caulking to the core, a laminated core 1d integrally assembled with the core retainer 1c, a coil winding 1e wound around the laminated core 1d, and a core. And a sinter bearing (bearing metal) 1f fitted in the presser 1c. The rotor-side assembly with a rotary table includes a rotary table 13 of a resin molded portion formed by insert-molding a rotor shaft 11 and an inverted cup-shaped rotor case 12, and an annular groove 13b around a boss 13a of the rotary table 13. Annular back yoke (back magnetic body) 14 fitted and fixed to the back yoke 1 in its annular groove 13b.
An annular permanent magnet for clamping attraction 15 fixed on the base 4 by self-adsorption and a rotor magnet 16 adhesively fixed to the inner peripheral surface of the rotor case 12 are provided.

The end surface of the rotor case 12 is buried in the rotary table 13 of the resin molding portion.
At least one cut-and-raised piece 12a stands on the thick portion of the hub 13c, and the cut-and-raised opening 12b forms a resin flow path at the time of molding and functions as a detent portion after molding. The end face of the rotor case 12 also functions as an aggregate of the turntable 13 of the resin molded part, and contributes to the strength of the turntable 13.

Rotor shaft 1 of spindle motor 1
Reference numeral 1 is not a round bar shaft. As shown in FIG. 2, a flat knurled marking portion 11a is formed on the peripheral surface of the tip. The flat knurled marking portion 11a can be easily provided in the coining process, which contributes to a reduction in the unit price of the rotor shaft 11.
Since the knurled marking portion 11a does not have a deep dent unlike a D-shaped cut, the risk of voids (bubbles) remaining in the cut portion during resin molding can be avoided, and a detent effect without rattling can be exhibited. In addition, a knurled knurled part may be used.

The rotary table 13 of this embodiment has a two-color resin molding structure, and a table body A of a first-color hard resin molding portion mixed with glass powder and the like, and a second-color rubber laminated and formed on the table body A. And a disk-slip-preventing layer B of the resin-like molded part. The boundary between the table body A and the disk anti-slip layer B is formed as a rough surface S.
In addition, in order to impart friction to the loaded disk medium,
The surface of the disc anti-slip layer B may also be formed as a roughened surface.

As described above, since the rotor side of the spindle motor and the rotary table are integrally formed as an insert molded product, the rotor shaft, the rotor case, and the rotary table are fixed to each other by caulking or press-fitting. This eliminates the need for expensive parts and intermediate parts, greatly reducing the number of manufacturing processes, and increasing the verticality between the rotor shaft and the rotor case and between the rotor shaft and the rotary table. High accuracy can also be achieved. As a result, the yield can be improved, and the cost of the apparatus can be reduced. In addition, the space formed between the rotor case and the rotary table can be eliminated by integration by insert molding, so that the rotary table driving device can be made thinner and the air resistance can be reduced.

Embodiment 2 FIG. 3 is a front view with a partial cross section showing a rotor side assembly with a rotary table of a rotary table driving device according to a second embodiment of the present invention.

The difference between the rotary table driving apparatus of the present embodiment and the first embodiment is that the back yoke of the magnet 15 is also used as the reduced diameter top plate 12c of the rotor case 12. An annular permanent magnet 15 for clamp attraction is directly attracted and fixed to the reduced diameter top plate portion 12c.

In this embodiment, in addition to the same effects as those of the first embodiment, a part of the rotor case 12 of the press-formed product is used as the back yoke of the annular magnet 15 for attracting the clamp. The manufacture and assembly of the yoke alone becomes unnecessary.

Embodiment 3 FIG. 4 is a front view with a partial cross section showing a rotor-side assembly with a rotary table of a rotary table driving device according to a third embodiment of the present invention, and FIG. 5 is a bottom view of the same device.

The rotor case 12 of this embodiment has a rotation preventing projection 13 of the turntable 13 at the case end face 12d.
It has a resin passage hole 12e for forming d in a discrete annular shape, and a radiation hole 12g is formed at a corner between the case peripheral wall 12f and the case end face 12d. The radiation hole 12g has a radiation V formed on the lower surface of the turntable 13.
The groove 13f is in communication. Therefore, the rotor case 12
12g of radiation hole and radiation V
It communicates via the groove 13f. When the rotary table 13 is rotated by the formation of such a communication path, an air current is generated from the hollow portion X as shown by a broken line in FIG. 6, so that the hot air generated by the coil winding 1e and the bearing 1f as shown in FIG. It will be transported out of the case with the help of convection, and will exhibit a remarkable heat dissipation effect. Note that the radiation V groove 13f may be formed in a spiral shape.

[0031]

As described above, the present invention is characterized in that the rotor side of the spindle motor and the rotary table are integrally formed as an insert molded product, and has the following effects.

The caulking and press-fitting between the rotor shaft, the rotor case and the rotary table are not required, and the manufacturing process can be significantly reduced without using costly parts or intermediate parts. In addition, the verticality between the rotor shaft and the rotor case and the verticality between the shaft and the rotary table can be improved. As a result, the yield can be improved, and the cost of the apparatus can be reduced. In addition, the space formed between the rotor case and the rotary table can be eliminated by integration by insert molding, so that the rotary table driving device can be made thinner and the air resistance can be reduced. Since the rotor shaft and the rotor case have a detent part in which the resin is depressed, an anchoring effect is exerted by the detent part in which the resin is depressed, and the rotor shaft and the rotor case and the resin molding part are formed. It is difficult for rattling to occur between them. In particular, the rotor
The detent of the case is cut and raised from the end face to the front side.
Cut and raised pieces that are embedded in the resin molding
Surface side resin layer at the end face and back side resin at the end face
The cut-and-raised opening as a resin flow passage connecting the layers
To form the rotor case,
A cut-off piece and a cut-off opening can be formed simultaneously on the surface.
Therefore, cost reduction can be realized, and
The strength of the rotary table with the end of the rotor case as the core material
Not only can it be improved and thinned,
In addition to the anchoring effect on the resin molded part of
Resin layer on the surface side of the resin molded part by resin flow through the part
And the backside resin layer are in a linked state to the end face.
As a result, a strong anti-rotation function can be demonstrated, achieving high reliability
I can .

[0033] In the configuration using the knurled stamped portion as the detent portion of the rotor shaft, there is no case where a gap remains during the molding and rattling occurs, and the yield can be improved.

The molding part of the turntable is 1
In the configuration of the two-color resin molding structure including the table main body of the color resin molding section and the disk anti-slip layer of the second color resin molding section laminated on the table main body, the number of steps can be further reduced and the number of steps can be reduced. Cost can be reduced.

In a configuration in which the boundary of the two-color resin molded structure is formed as a rough surface with irregularities, delamination can be suppressed.

In a configuration in which a part of the rotor case is also used as a back yoke of the attraction permanent magnet for clamping, a dedicated part of the back yoke can be eliminated, and the cost can be further reduced.

[0037]

[Brief description of the drawings]

FIG. 1 is a front view with a partial cross section showing a rotor-side assembly with a rotary table of a rotary table driving device according to a first embodiment of the present invention.

FIG. 2A is a plan view of a rotor shaft in the rotary table driving device according to the first embodiment, and FIG. 2B is a front view thereof.

FIG. 3 is a front view with a partial cross section showing a rotor-side assembly with a rotary table of a rotary table driving device according to a second embodiment of the present invention.

FIG. 4 is a front view with a partial cross section showing a rotor-side assembly with a rotary table of a rotary table driving device according to a third embodiment of the present invention.

FIG. 5 is a bottom view of a rotary table driving device according to a third embodiment.

FIG. 6 is a front view with a partial cross section showing a separated state of a rotary table driving device provided with a conventional magnetic attraction type disk pressing mechanism.

FIG. 7A is a front view with a partial cross section showing a state in which a rotor shaft and a brass spacer are press-fitted and assembled in the same conventional apparatus, and FIG. 7B is a caulking of the rotor case and the brass spacer in the same conventional apparatus. FIG. 3C is a front view with a partial cross section showing a fixed state, and FIG. 4C is a front view with a partial cross section showing a rotary table in the conventional device.

FIG. 8 is a front view with a partial cross section showing a rotor-side assembly with a rotary table in the conventional device.

[Explanation of symbols]

 Reference Signs List 1 spindle motor 1b printed wiring board (mounting base) 1c core holder (bearing housing) 1d laminated core 1e coil winding 11 rotor shaft 11a plain knurl stamp 12 rotor case 12a Piece 12b Cut-and-raised opening 12c Reduced diameter top plate 12d Case end face 12e Resin passage hole 12f Case peripheral wall 12g Radiation hole 13 Rotary table of resin molding portion 13a Boss 13b Annular groove 13d Stop projection 13f ... Radiation V-groove 14 ... Back yoke 15 ... Ring permanent magnet for clamping attraction 16 ... Rotor magnet A ... Table body of the first color hard resin molded part B ... Disc slip prevention layer of the second color rubbery resin molded part S ... Uneven surface.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 64-15355 (JP, U) JP-A 1-116955 (JP, U) JP 2-76362 (JP, U) JP-A 4- 93943 (JP, U) Actually open 1988-10761 (JP, U)

Claims (5)

(57) [Claims] 1. A rotary table driving device including a spindle motor for rotating a rotary table on which a disk medium is to be mounted, wherein the rotary table includes a rotor for the spindle motor.
A resin molded portion formed by resin molding by inserting a shaft and an end surface portion of a rotor case, wherein the rotor shaft and the rotor case each have a detent portion in which molded resin is depressed; A detent part of the case is cut and raised from the end face to the front side and buried in the resin molded part, a surface-side resin layer of the end face in the resin forming part, and the end face. And a cut-and-open opening as a resin flow passage connecting the back surface side resin layer to the rotary table driving device. 2. The rotary table driving device according to claim 1, wherein the detent portion of the rotor shaft is a knurled marking portion. 3. The rotary table according to claim 1, wherein the rotary table includes a table main body of a first-color resin molded portion, and a disk anti-slip layer of a second-color resin molded portion laminated and formed on the table main body. A rotary table driving device having a two-color resin molding structure comprising: 4. The rotary table driving device according to claim 3, wherein a boundary between the table main body and the disk anti-slip layer is a roughened surface. 5. The rotary table driving device according to claim 1, wherein a part of the rotor case is also used as a back yoke of a permanent magnet for clamping.