JP2000348426A - Rotary table apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary table apparatus that can be expected to reduce the cost of parts and to improve the production yield by making a hub presser itself having a clamp attracting magnet, plastic. SOLUTION: The rotary table apparatus comprises a spindle motor 10, and a rotary table 20' fixed at the tip end portion of an outer rotor case 3 provided with a boss section 22 inserted to the tip side of a rotor shaft 4. The rotary table 20' has a ring-shaped groove 22a formed at the outer periphery of the boss section, and a hub sliding wall section 22b formed integrally. A hub 27 axially slidably fitted outwardly onto the outer peripheral surface of the hub sliding wall section 22b, being biased upward by means of a loading spring 25, and a hub presser 26' made of resin and insert-molded with a back yoke provided integrally at the bottom of a magnetic accommodating hole 26b. The hub is covered with the hub presser with an axial hole of the back yoke being press-fitted into the tip portion of the rotor shaft so as to prevent detachment, and a clamp attracting magnet superposed onto the back yoke in the magnetic accommodation hole. Since the hub sliding wall section is integrally formed on the side to the rotary table side, the hub presser itself can be formed of plastics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary disk device for a disk medium such as an MDD, and more particularly to an integrated rotary disk device having a rotary table and a spindle motor.

[0002]

2. Description of the Related Art For example, a turntable device of an MD player is:
As shown in FIG. 4, an upright bottomless cylindrical bearing housing (core presser) 2 fixed by caulking to a printed wiring board (attachment base plate) 1 attached to a chassis (not shown) on the player body side. A backside 21 is fixed by caulking to the top end of a spindle motor (brushless motor) 10 and its inverted cup-shaped iron outer rotor case 3 to form a boss 2.
2, a brass rotary table 20 press-fitted into the rotor shaft 4, a brass hub press 26 having an umbrella-shaped hub stopper 26a, which is press-fitted onto a boss portion 22 of the rotary table 20, and this hub press. The outer peripheral surface of the shaft 26 is slidable in the axial direction and is urged upward by the loaded coil spring 25 to be prevented from falling off by the hub stopper 26a. An iron-made annular back yoke plate 24 press-fitted into the tip of the rotor shaft 4 and located on the stepped portion 26c; a clamp-suction annular sintered magnet 28 bonded and fixed on the back yoke plate 24; have. The disk medium D is the disk receiving cushion portion 2 on the outer peripheral side of the turntable 20.
When the disk holder is loaded on the hub holder 26a, a disk holder (not shown) is superimposed on the hub holder 26, and an iron disk (magnetic material) with a built-in disk holder, a ring-shaped sintered magnet 28 for clamping and clamping are provided. Are brought into close contact with each other by the magnetic attraction force to clamp the disk medium.

[0003]

However, the above-mentioned rotary disc device has the following problems.

As a material of the rotary table 20, brass is generally used because of its machinability, low weight due to inertial mass, low deformability and low thermal expansion. Brass is also used to make the resin hub 27 slidable up and down smoothly on the outer peripheral surface. If the hub retainer 26 is made of brass, it will be manufactured by cutting, so that high manufacturing costs cannot be avoided.

Further, the hub retainer 26 is connected to the rotary table 2
0, and the back yoke plate 24 is press-fitted into the magnet storage hole 26b of the hub retainer 26, and the hub stopper of the hub retainer 26 depends on the press-fit margin and press fit. There is a difference in the degree to which the 26a slightly expands outward, and variations in sliding of the hub 27 occur for each product, which causes a reduction in yield.

In view of the above problems, it is an object of the present invention to provide a turntable device which can be expected to reduce the cost of parts and improve the yield by making the hub retainer itself having the magnet for clamping attraction plastic. It is in.

[0007]

According to a first aspect of the present invention, there is provided a spindle motor having a boss portion fixed to a top end of an outer rotor case and having a boss at a tip end of a rotor shaft. A rotary table having a press-fitted rotary table, wherein the rotary table integrally has a hub slidable wall portion with an annular groove formed in an outer periphery of the boss portion; A hub, which is externally fitted to the outer peripheral surface of the magnet and is slidable in the axial direction and urged upward by a loading spring, and a back yoke integrally provided at the bottom of the magnet housing hole and made of insert molded resin; A hub retainer, wherein the hub retainer covers the hub in a state where the shaft hole of the back yoke is pressed into the tip of the rotor shaft, and is clamped on the back yoke in the magnet storage hole. For magnet Sleep, characterized in that it consists in.

In such a means, since the hub sliding wall portion is not provided on the hub press side but is provided integrally on the rotary table side, the hub press itself may not be made of brass. Instead of plastic. Therefore, since the hub retainer can be made of a resin molded product, the cost of the component can be reduced. Further, even if the shaft hole of the back yoke is press-fitted into the rotor shaft and the hub retainer slightly expands to the outer peripheral side, the hub retainer does not have a sliding portion of the hub and merely covers the hub. The sliding surface does not have to expand outwards, and there is no variation in the sliding of the hub for each product.Moreover, the hub can be arranged without the intermediation of the hub retainer, realizing high accuracy. Contribute to yield improvement. Further, since the hub retainer is an insert molded product integrally provided with the back yoke, the number of assembling steps can be reduced and the manufacturing cost can be reduced.

Here, the annular groove separates the boss from the hub sliding wall so that when the boss of the rotary table is press-fitted into the rotor shaft, the press-fit distortion does not affect the hub sliding surface. However, the hub retainer has an annular thick portion formed integrally with a back yoke on the back side thereof, and the annular thick portion is fitted into the annular groove of the rotary table with a gap. An annular thick portion can be secured on the hub holding side by the space of the annular groove on the rotary table side, and the integral fixing force of the back yoke can be strengthened, and the detent function can be enhanced.

According to a second aspect of the present invention, there is provided a rotary disk apparatus comprising a spindle motor and a rotary table fixed to a top end of an outer rotor case and having a boss press-fitted to a tip end of a rotor shaft. The rotary table has a hub sliding wall integrally formed with an annular groove in the outer periphery of the boss portion, and is fitted on the outer peripheral surface of the hub sliding wall so as to be slidable in the axial direction. And a hub press made of a plastic magnet integrally formed with a metal shaft press-fitting portion and integrally formed with a metal shaft press-fitting portion. The metal shaft press-fitting portion is attached to the tip of the rotor shaft. The hub presser is formed so as to cover the hub and prevent the hub from being pulled out while being pressed into the portion.

[0011] Also in this means, since the hub slidable wall portion is not provided on the hub press side but is provided integrally on the rotary table side, the hub press itself may not be made of brass. Instead of plastic. Therefore, since the hub retainer can be made of a resin molded product, the cost of the component can be reduced. Also, even if the shaft press-fitting portion is press-fitted into the rotor shaft and the hub presser slightly expands to the outer peripheral side, the hub presser does not have a hub sliding portion,
However, since it merely covers the hub, the sliding surface of the hub does not have to expand outward, there is no variation in the sliding of the hub for each product, and the hub can be moved without going through the hub retainer. Since they can be arranged, high precision can be realized, contributing to an improvement in yield. Since the hub retainer is made of an insert-molded plastic magnet integrally provided with a metal shaft press-fit portion, it is not only necessary to reduce the number of assembling steps, but also it is not necessary to incorporate magnet parts. This contributes to lower manufacturing costs.

Here, if a structure is adopted in which the metal shaft press-fitting portion has an integral fixing portion with the hub press at its lower part, the metal shaft press-fit portion and the plastic magnet hub press are combined. The fixing force is strengthened, and the detent function can be enhanced.

When the metal shaft press-fitting portion is a magnetic material, it simultaneously functions as a back yoke, so that the clamping force can be increased.

The metal shaft press-fitting portion may be an inexpensive iron forged product. However, when an iron sintered alloy is used, an appropriate press-fitting margin can be obtained despite being a magnetic material, so that the press-fit joining force increases. The mounting reliability of the hub retainer can be secured.

According to the present invention, the outer periphery of the disk receiving cushion attached to the rotary table is formed integrally with the rotary table at a height less than the thickness of the disk receiving cushion (for example, half the height). It is preferable to include a formed annular small ridge. There is no problem when the disk medium is loaded from a direction substantially perpendicular to the surface of the disk receiving cushion portion, but the loading direction is substantially parallel to the surface (for example, 10
°), the back surface of the disk medium and the outer peripheral portion of the disk receiving cushion portion are rubbed, so that the outer peripheral portion is worn due to long-term use, and it is difficult for the disk hole of the disk medium to fit in the hub in a normal posture. Become. However, since the small annular ridge is formed on the outer periphery in the vicinity, the small annular ridge functions as a stop for the back surface of the disk medium,
Rubbing of the outer peripheral side portion of the disk receiving cushion portion can be suppressed, and the disk hole of the disk medium always fits in the hub in the normal posture, so that the durability of the turntable device can be enhanced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
5 is a side view showing a state in which a right half of the turntable device of the MD player according to the first embodiment is longitudinally cut.

The rotating disk device of the present embodiment is a cylindrical bearing housing (core holding member) having an upright bottom which is fixed by caulking to a printed wiring board (mounting base plate) 1 mounted on a chassis (not shown) on the player body side. A) a spindle motor (brushless motor) 10 having a 2 'and an inverted cup-shaped iron outer rotor case 3 having its back 21 fixed to the top end thereof and a boss 22 press-fitted into the rotor shaft 4;
A rotary table 20 'made of brass having an annular groove 22a in the outer periphery of the boss portion 22 and integrally having a hub slidable wall portion 22b.
A hub 27 made of a cone-shaped resin which is fitted on the outer peripheral surface of the hub slidable wall portion 22b and is slidable in the axial direction and urged upward by the loaded coil spring 25; The back yoke 24 'made of steel sheet metal with
b, the umbrella-shaped hub stopper 26a
And a hub retainer 26 'made of insert-molded polycarbonate resin. This back yoke 2
The hub retainer 26 'covers the hub 27 while the shaft hole 4' is pressed into the tip end of the rotor shaft 4 to prevent the hub 27 from slipping out. (Sintered magnet) 28 are stacked.

The hub retainer 26 'has an annular thick portion 26d integrally molded with a back yoke 24' on the back side thereof. The annular thick portion 26c is fitted into the annular groove 22a of the rotary table 20 with a gap. I have.

On the outer periphery in the vicinity of the disk receiving cushion portion 20a attached to the rotary table 20, an annular small ridge 20b is formed integrally with the rotary table 20 at a height of about half the thickness of the disk receiving cushion portion 20a. Are formed.

Reference numeral 5 denotes a thrust receiving plate for supporting the lower end of the rotor shaft 4, reference numeral 6 denotes a bearing metal of the rotor shaft 4, reference numeral 7 denotes a laminated core of the stator, reference numeral 8 denotes a winding coil, reference numeral 9 denotes a rotor magnet, and reference numeral 11 denotes a rotor. Rotor stopper stopper press-fitted into the circumferential groove of the shaft 4, 12 is a bearing metal oil guard,
Reference numeral 13 denotes a Hall element.

In this embodiment, since the hub sliding wall portion 22b is not provided on the hub retainer 26 'side but is provided integrally on the brass rotary table 20' side, the hub retainer wall portion 22b is provided. 26 'itself does not have to be made of brass and is a resin molded product. For this reason, cost reduction of parts can be achieved.

Even if the shaft hole of the back yoke 24 'is press-fitted into the rotor shaft 4 and the hub retainer 26' slightly expands to the outer peripheral side, the hub retainer 26 'does not have the hub slidable portion 22b, However, since the lower end of the hub stopper 26a of the hub retainer 26 only abuts on the upper end of the hub 27, the sliding surface of the hub itself does not have to expand outward, and the variation in the sliding of the hub for each product is reduced. It does not occur, and hub presser 2
Since the hub can be arranged without the interposition of 6 ', high precision can be realized, which contributes to improvement in yield.

Further, the hub retainer 26 'is connected to the back yoke 2
Since it is an insert-molded product integrally including 4 ', the number of assembling steps can be reduced, which contributes to a reduction in manufacturing cost.

The annular groove 22a is formed between the boss 22 and the sliding wall of the hub so that when the boss 22 of the rotary table 20 'is pressed into the rotor shaft 4, the press-fit distortion does not affect the hub sliding surface. 22b. The hub retainer 26 'has an annular thick portion 26d on the back side for integrally molding the back yoke 24'.
Are fitted into the annular groove 22a of the rotary table with a gap. The annular thick portion 26d can be secured on the side of the hub retainer 26 'by the space of the annular groove 22a on the turntable 20' side, and the integral fixing force of the back yoke 24 'can be strengthened and the detent function can be enhanced. Further, since the outer notch 24a is formed in the back yoke 24 ', the fixing force of the resin is enhanced, which contributes to the improvement of the rotation preventing function.

Here, the disc receiving cushion portion 20a
No problem occurs when the disk medium D is loaded from a direction substantially perpendicular to the surface of the disk medium D, but when the loading direction is substantially parallel to the surface (for example, 10 °), the back surface of the disk medium D and the disk Since the outer peripheral side portion E of the cushion portion 20a is rubbed, the outer peripheral side portion E is worn out due to long-term use, and it becomes difficult for the disk hole of the disk medium D to fit in the hub 27 in a normal posture. However, in this example, since the small annular ridge 20b is formed on the outer periphery in the vicinity, as shown in FIG.
0b functions as a stop on the back surface of the disk medium D, and the rubbing of the outer peripheral side portion of the disk receiving cushion portion 20a can be suppressed, and the disk hole of the disk medium D always fits in the hub 27 in the normal posture. For this reason, the durability of the turntable device can be improved.

(Embodiment 2) FIG. 2 shows Embodiment 2 of the present invention.
5 is a side view showing a state in which a right half of the turntable device of the MD player according to the first embodiment is longitudinally cut. The same parts as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The rotating disk device of this embodiment is an upright bottomed cylindrical bearing housing (core retainer) fixed by caulking to a printed wiring board (mounting base plate) 1 mounted on a chassis (not shown) on the player body side. A) a spindle motor (brushless motor) 10 having a 2 'and an inverted cup-shaped iron outer rotor case 3 having its back 21 fixed to the top end thereof and a boss 22 press-fitted into the rotor shaft 4;
A rotary table 20 'made of brass having an annular groove 22a in the outer periphery of the boss portion 22 and integrally having a hub slidable wall portion 22b.
A hub 27 made of a cone-shaped resin which is fitted on the outer peripheral surface of the hub slidable wall portion 22b and is slidable in the axial direction and urged upward by the loaded coil spring 25; 29
And a hub retainer 26 ″ made of a plastic magnet and integrally molded with the hub retainer 26 ″. The hub retainer 26 ″ is press-fitted with the metal shaft press-fit portion 29 into the tip of the rotor shaft 4. It is formed so as to prevent the hub 27 from slipping off.

The lower portion of the metal shaft press-fitting portion 29 is a flange-shaped enlarged portion 29a, and through holes 29b are formed at equal intervals around the flange-shaped enlarged portion 29a, so that the resin penetrates. ing.

The function of preventing the insert molded product from rotating is sufficiently achieved by this interpenetrating portion.

The metal shaft press-fitting portion 29 is a magnetic material of an iron sintered alloy or an iron forging, and also has a function of a back yoke. In the case of using an iron sintered alloy, an appropriate press-in allowance can be obtained despite being a magnetic material, so that press-fit joining force increases, and assembling reliability of the hub retainer can be secured.

Also in this embodiment, since the hub slidable wall portion 22b is not provided on the hub retainer 26 "side but is provided integrally on the rotary table 20 'side, the hub retainer 26" itself is provided. May not be made of brass, but can be made of plastic. Therefore, since the hub retainer 26 "can be made of a resin molded product, the cost of parts can be reduced.

Even if the shaft press-fitting portion 29 is press-fitted into the rotor shaft 4 and the hub presser 26 "slightly expands to the outer peripheral side,
The hub retainer 26 ″ does not have a sliding portion of the hub.
, The sliding surface of the hub does not need to be expanded outward, there is no variation in the sliding adjustment of the hub 27 for each product, and the hub does not pass through the hub retainer 26 ". Can be arranged, so that high accuracy can be realized, which contributes to an improvement in yield.

Then, the hub retainer 26 ″ is connected to the metal shaft press-fit portion 2.
Since it is made of an insert-molded plastic magnet integrally provided with No. 9, it is not only necessary to reduce the number of assembling steps, but also it is not necessary to incorporate a magnet part, and the reduction in the number of parts contributes to a further reduction in manufacturing cost. .

[0035]

As described above, according to the present invention, since the hub slidable wall is not provided on the hub holder but is provided integrally on the rotary table side, the hub holder itself is provided. May not be made of brass, but can be made of plastic. Therefore, the following effects are obtained.

Since the hub retainer can be made of a resin molded product, the cost of parts can be reduced. Also, even if the shaft hole of the back yoke is press-fitted into the rotor shaft and the hub presser slightly expands to the outer peripheral side, the sliding surface of the hub does not have to expand outward, and the hub slides for each product. Since there is no variation in adjustment and the hub can be arranged without the intermediation of the hub retainer, high precision can be realized, which contributes to an improvement in yield. Further, since the hub retainer is an insert molded product integrally provided with the back yoke, the number of assembling steps can be reduced and the manufacturing cost can be reduced.

The hub retainer has an annular thick portion on the back side for integrally molding the back yoke, and when the annular thick portion is fitted into the annular groove of the rotary table with a gap, the rotary table is rotated. An annular thick portion can be secured on the hub holding side by the space of the annular groove on the side, the integral fixing force of the back yoke can be strengthened, and the detent function can be enhanced.

When the hub retainer is made of an insert-molded plastic magnet integrally provided with a metal shaft press-fitting portion, it is not only necessary to reduce the number of assembling steps, but also it is not necessary to incorporate a magnet part, and the number of parts is reduced. It contributes to further reduction of manufacturing cost.

If a structure is adopted in which the metal shaft press-fitting portion integrally has an integral fixing portion with the hub press at the bottom side of the hub press, the metal shaft press-fitting portion and the plastic magnet hub press are combined. Becomes stronger and the detent function can be enhanced.

When the metal shaft press-fitting portion is a magnetic material, it simultaneously functions as a back yoke, so that the clamping force can be increased.

When the metal shaft press-fitting portion is made of an iron sintered alloy, an appropriate press-fitting margin can be obtained even though it is a magnetic material, so that the press-fitting joining force increases and the assembling reliability of the hub retainer can be secured.

Further, on the outer periphery in the vicinity of the disk receiving cushion portion stuck on the rotary table, an annular small size integrally formed with the rotary table at a height equal to or less than the thickness of the disk receiving cushion portion (for example, half the height). If the configuration having the ridge is adopted, when the loading direction is substantially parallel to the surface of the disc receiving cushion portion,
The annular small ridge functions as a stop for the back surface of the disk medium, and can suppress the rubbing of the outer peripheral portion of the disk receiving cushion portion. The durability of the device can be increased.

[Brief description of the drawings]

FIG. 1 is a side view showing a state in which a right half of a turntable device of an MD player according to a first embodiment of the present invention is longitudinally cut.

FIG. 2 is a side view showing a loading state in which a disk medium is placed on a rotary table in the MDD rotating disk apparatus.

FIG. 3 is a side view showing a state in which a right half of a turntable device of an MD player according to a second embodiment of the present invention is longitudinally cut.

FIG. 4 is a side view showing a state in which a right half of a conventional turntable device of an MD player is longitudinally cut.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printed wiring board (mounting base plate) 2, 2 '... Bearing housing (core presser) 3 ... Inverted cup-shaped iron outer rotor case 4 ... Rotor shaft 5 ... Thrust receiving plate 6 ... Bearing metal 7 ... Laminated core 8 ... winding coil 9 ... rotor magnet 10 ... spindle motor (brushless motor) 11 ... rotor retaining stopper 12 ... oil guard 13 ... hole element 20,20 '... rotary table 20a ... disk receiving cushion part 20b ... annular small ridge DESCRIPTION OF SYMBOLS 21 ... Back part 22 ... Boss part 22a ... Annular groove 22b ... Hub sliding wall part 24, 24 ', 24 "... Back yoke 24a ... Peripheral notch 25 ... Loaded coil spring 26, 26', 26" ... Hub retainer 26a ... Hub stopper 26b ... Magnet storage hole 26c ... Step 26d ... Thick annular portion 27 ... Hub 28 ... Clamp attraction magnet (sintered magnet) ) 29 ... metal shaft press-fit section 29a ... flanged enlarged diameter portion 29 b ... hole D ... disk medium E ... outer peripheral portion.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoto Shiga 1776 Kawahara Kamimaruko, Marumachi-gun, Nagano Prefecture Inside Sanyo Seimitsu Co., Ltd. Sanyo Seimitsu Co., Ltd. F term (reference) 5D109 BA14 BA16 BA18 BA28 BA34 5H621 BB07 GA01 GA04 GA17 HH02 HH06 JK02 JK08 JK14 JK15 JK19

Claims (7)

[Claims] 1. A rotating disk device comprising: a spindle motor; and a rotary table fixed to a top end of an outer rotor case and having a boss portion press-fitted to a tip end of a rotor shaft, wherein the rotary table has a boss portion. An annular groove is formed in the outer periphery, and a hub sliding wall portion is integrally provided. The hub sliding wall portion is externally fitted to the outer peripheral surface of the hub sliding wall portion, and is slidable in the axial direction and upward by a loading spring. It has a hub to be urged, and a hub made of resin that is integrally provided with a back yoke at the bottom of the magnet housing hole and is formed by insert molding. The shaft hole of the back yoke is provided at the tip of the rotor shaft. The rotating disk device, wherein the hub presser is prevented from slipping over the hub in a press-fit state, and a clamp attraction magnet is superimposed on the back yoke in the magnet housing hole. 2. The hub press according to claim 1, wherein the hub retainer has an annular thick portion on the back side for integrally molding the back yoke, and the annular thick portion is fitted with a gap into an annular groove of the rotary table. A turntable device characterized by being locked. 3. A rotary disk device comprising: a spindle motor; and a rotary table fixed to a top end of an outer rotor case and having a boss portion press-fitted to a tip end side of a rotor shaft, wherein the rotary table has a boss portion. An annular groove is formed in the outer periphery, and a hub sliding wall portion is integrally provided. The hub sliding wall portion is externally fitted to the outer peripheral surface of the hub sliding wall portion, and is slidable in the axial direction and upward by a loading spring. A state in which a hub to be urged and a hub made of insert-molded plastic magnet integrally provided with a metal shaft press-in portion are press-fitted into the tip of the rotor shaft. Wherein the hub retainer covers the hub and prevents the hub from slipping off. 4. The rotating disk device according to claim 3, wherein the metal shaft press-fitting portion integrally has an integral fixing portion with the hub retainer at a lower portion thereof. 5. The rotating disk device according to claim 3, wherein the metal shaft press-fitting portion is a magnetic material. 6. The rotating disk device according to claim 5, wherein the metal shaft press-fitting portion is made of an iron sintered alloy or an iron forged product. 7. The disk drive according to claim 1, wherein the outer periphery of the disk receiving cushion attached to the rotary table has a height equal to or less than the thickness of the disk receiving cushion. A turntable device comprising an annular small ridge formed integrally with a table.