JPH0660531A - Spindle mechanism - Google Patents

Abstract

PURPOSE:To make a size small in an axial direction and to reduce the number of parts and assembling man-hour in a spindle mechanism for a recording medium disk. CONSTITUTION:A motor 15 is constituted of a rotary shaft 7 rotatably supported by the bearing part 11 of a motor base 2, stator coils 9, 9,... arranged around the shaft, and a rotor case 10 having a lower surface on which a rotor magnet 14 opposed to the stator coil is fixed and a center part 13 coupled with the rotary shaft. A centering guide 17 is provided in the center part of the upper surface wall 11 of the rotor case and the center part of the recording medium disk 16 is attachably/detachably placed on the upper surface plate of the rotor case.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel spindle mechanism. More specifically, the present invention relates to a spindle mechanism including a turntable on which a recording medium disc is detachably mounted, and a turntable as a special component can be omitted, which reduces the size in the axial direction considerably. The present invention intends to provide a novel spindle mechanism which can reduce the number of parts and the number of assembling steps.

[0002]

2. Description of the Related Art As a mechanism for rotating a recording medium disc such as an optical disc, a turntable (also referred to as a "chucking table") on which a central portion of the recording medium disc is detachably mounted is a motor. A spindle mechanism having a structure coupled to the rotating shaft of is used.

FIG. 9 shows an example a of a conventional spindle mechanism.

In the figure, b is a motor fixed to the lower surface of the chassis c, and d is its rotating shaft, which projects above the chassis c.

Reference numeral e denotes a disc-shaped turntable having a press-fitting hole f formed in the center thereof, and a portion of the rotary shaft d of the motor b projecting upward from the chassis c is press-fitted into the press-fitting hole f. Thus, the turntable e is coupled so as to be rotated by the motor b.

Reference numeral g denotes a centering guide integrally provided on the upper surface of the turntable e coaxially therewith.

Reference numeral h denotes a recording medium disk, which is detachably mounted on the turntable e so that the centering guide g is fitted in the center hole i thereof.

The recording medium disk h placed on the turntable e is held by a chucking plate (not shown) which is rotatably supported by the fixed member, and is supported so as to rotate together with the catching plate. .

When the motor b is rotated, the turntable e is rotated integrally with the recording medium disc h.

[0010]

In such a conventional spindle mechanism a, since the turntable e and the centering guide g are dedicated parts, the number of parts is large and the dimension in the axial direction is large. There is a problem that it is difficult to reduce the size.

Further, in such a spindle mechanism a, extremely high precision is required for processing and assembling each part of the rotating recording medium disk h in order to prevent the wobbling of the recording medium disk h. It

Particularly, the upper surface of the turntable e and the press-fitting hole f
Needless to say, each part needs to be processed with high precision.
It is important that the upper surface of the turntable e is accurately connected to the rotation axis d of the motor b in a direction orthogonal to the axial direction, which is a major cause of increasing the cost of the spindle mechanism a. Was becoming.

In order to accurately connect the turntable e and the rotary shaft d, it is necessary to increase the contact area between the inner peripheral surface of the press-fitting hole f of the turntable e and the outer peripheral surface of the rotary shaft d. The length of the press-fitting hole f, that is, the axial length (thickness) of the turntable e must be increased, which is one of the causes of increasing the axial dimension of the spindle mechanism a. Was becoming.

[0014]

In order to solve the above-mentioned problems, the spindle mechanism of the present invention has a turntable in which the central portion of the recording medium disk is removably mounted on the upper surface plate of the rotor case of the motor. It is what

[0015]

Therefore, in the spindle mechanism of the present invention, since the turntable as a dedicated part is not necessary, the number of parts and the labor of assembling can be reduced, and the cost can be greatly reduced. You can

Moreover, since the upper plate of the rotor case of the motor serves as a turntable as it is, the dimension in the axial direction can be reduced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the spindle mechanism of the present invention will be described below with reference to the embodiments shown in the accompanying drawings.

1 to 4 show a first embodiment 1 of the spindle mechanism according to the present invention.

Reference numeral 2 denotes a motor base, which is composed of a substantially disk-shaped base portion 3 and a cylindrical bearing portion 4 protruding upward from a central portion thereof, and the base portion 3 is fixed to a chassis 5.

Reference numerals 6 and 6 are ball bearings provided in the upper and lower portions of the hole 4a of the bearing portion 4 so as to be fitted therein.

Reference numeral 7 denotes a rotating shaft, which has a length approximately twice as long as the length of the bearing portion 4 of the motor base 2, and the lower half thereof is supported by the ball bearings 6 and 6 in an internally fitted shape. As a result, the rotary shaft 7 is rotatably supported by the motor base 2.

Reference numeral 8 denotes a stator substrate, on the upper surface of which a large number of flat stator coils 9, 9, ... Arranged at equal intervals in the circumferential direction are arranged.

The stator substrate 8 has an insertion hole 8 formed at the center of the arrangement of the stator coils 9, 9 ,.
is fixed to the upper surface of the base portion 3 with the bearing portion 4 of the motor base 2 being inserted, whereby the stator coils 9, 9, ... Are arranged around the axis of the rotary shaft 7.

Reference numeral 10 denotes a rotor case formed of a magnetic metal such as iron, which is a disc-shaped upper surface plate 1 having a diameter approximately twice the diameter of a center hole of a recording medium disk described later.
1, and an outer peripheral wall 12 that extends downward from the outer peripheral edge thereof,
The boss portion 13 has a substantially cylindrical shape with a small axial dimension, and the boss portion 13 is formed so as to project downward from the central portion of the upper surface plate 11.

The rotor case 10 is integrally formed by pressing, forging or the like.

Reference numeral 14 denotes a rotor magnet having a flat ring shape and having S poles and N poles alternately magnetized in the circumferential direction,
It is fixed to the lower surface of the upper surface plate 11 of the rotor case 10.

The rotor case 10 has the boss portion 1
A position closer to the upper end of the rotary shaft 7 is press-fitted into the rotary shaft 7 from the center in the vertical direction, so that the rotor case 10 and the rotary shaft 7 are integrally coupled, and the rotor magnet 14 and the stator coil 9 are connected. , 9, ... Are placed opposite each other with a predetermined gap.

Thus, the plane-opposed outer rotor type motor 15 is constructed as described above, and when a drive current is supplied to the stator coils 9, 9, ..., Rotational force is applied to the rotor magnet 14. Thus, the rotor case 10 is rotated.

The top plate 1 of the rotor case 10
Reference numeral 1 also serves as a turntable on which the central portion of the recording medium disc 16 is detachably mounted.

Reference numeral 17 denotes a synthetic resin centering guide,
That is, it is a positioning member for positioning the recording medium disc 16 with respect to the turntable, and has a relatively thick disc shape having the same size as the center hole 16a of the recording medium disc 16 or a slightly smaller outer diameter. And a press-fitting hole 1 that is slightly smaller than the shaft diameter of the rotating shaft 7 in the center thereof.
7a is formed, and a portion where the outer peripheral surface and the upper surface are continuous is formed as a conical slope.

In the centering guide 17, the upper end portion of the rotary shaft 7 is press-fitted into the press-fitting hole 17a, and the lower surface thereof is the upper surface 11a of the upper plate 11 of the rotor case 10 (hereinafter referred to as "disk mounting surface"). ) Is glued to.

Then, the recording medium disk 16 is mounted on the disk mounting surface 11a such that the centering guide 17 is fitted in the center hole 16a.

Further, the recording medium disk 16 thus mounted is pressed against the disk mounting surface 11a with the recording medium disk 16 sandwiched therebetween, and by a chucking plate (not shown) rotatably supported with respect to the fixed member. It is held and supported for rotation with the chucking plate.

Therefore, by rotating the rotor case 10, the recording medium disk 16 is rotated integrally with the rotor case 10.

FIG. 3 shows a modification 10 of the rotor case 10.
The rotor case 10A has a boss portion 13 protruding upward.

Therefore, the length of the boss portion 13 in the axial direction can be increased within a range that does not hinder the mounting of the recording medium disc 16 (in the drawing, it is substantially the same as the thickness of the centering guide 17). .), The accuracy of the coupling with the rotary shaft 7 can be increased accordingly.

FIG. 4 shows a modification of the centering guide.

Reference numeral 10B is a rotor case, and a circular mounting hole 18 is formed in the center of the upper surface plate 11 thereof.

Reference numeral 17A denotes a metal centering guide, which is integrally formed with a cylindrical projection 19 projecting downward from the center of the centering guide 17A. The hole 19a of the projection 19 has a center portion of the centering guide 17A. Has been penetrated.

The protrusion 19 is inserted through the mounting hole 18 of the rotor case 10B from above, and the portion protruding from the mounting hole 18 is crimped so as to be expanded in diameter.
The centering guide 17A is fixed to the rotor case 10B.

Thus, such a rotor case 10B
Is press-fitted into the hole 19a of the centering guide 17A at the upper end of the rotary shaft 7 and is integrally connected to the rotary shaft 7.

With this structure, the center of the centering guide 17A and the axis of the rotary shaft 7 can be relatively easily aligned with each other.

FIG. 5 shows a second embodiment 20 of the spindle mechanism according to the present invention.

The spindle mechanism 20 of the second embodiment differs from the spindle mechanism 1 of the first embodiment mainly in the structure of the motor and the rotor case of the centering guide. Only the mounting structure of.

Therefore, the description will be made only for the above-mentioned differences, and for the other parts, the same reference numerals as those for the same parts in the spindle mechanism 1 or the uppercase alphabetical symbols will be attached to the respective parts in the drawings. The description is omitted by attaching the reference numerals.

The usage of such a code and its meaning are the same in the third and fourth embodiments described later.

Denoted by 21, 21, ... are stator coils wound around an iron core (not shown), and are supported by the bearing portion 4 while being arranged around the axis of the bearing portion 4 of the motor base 2.

The vertical width of the outer peripheral wall 12 of the rotor case 10C in this embodiment is the same as the stator coil 2 described above.
1, 21, ... Enclose the entire size, and the annular rotor magnet 22 having a short axial dimension is bonded to the inner peripheral surface of the outer peripheral wall 12 for the size of the diameter. The rotor magnet 22 is magnetized so that the polarities on its inner peripheral surface are alternately different in the circumferential direction.

Thus, the rotary shaft 7 and the rotor case 10C
And the stator coil 21 and the like constitute an iron core coil type outer rotor type motor 23.
When a drive current is supplied to 21, ..., Rotating force is applied to the rotor magnet 22, which causes the rotor case 10C to rotate.

The centering guide 17B is formed integrally with the rotor case 10C by outsert molding of synthetic resin.

That is, first, the mounting holes 24, 2 arranged so as to surround the boss portion 13 on the upper surface plate 11 of the rotor case 10C.
4 are formed, and such a rotor case 10C is positioned in a molding die (not shown) when molding the centering guide 17B.

Next, the molten resin is injected into the molding die, and the upper surface of the upper surface plate 11 of the rotor case 10C, the mounting holes 24 and 2 are attached.
The molten resin is positioned around the mounting holes 24, 24, ...

When the molten resin hardens, the rotor case 10
The synthetic resin on the upper surface of the upper surface plate 11 of C, the partial synthetic resin on the lower surface, and the synthetic resin in the mounting holes 24, 24, ... Are integrally combined with the upper surface plate 11 of the rotor case 10C,
The centering guide 17B is formed.

Since the centering guide 17B is formed in this way, the accuracy of the positional relationship with respect to the rotor case 10C can depend on the accuracy of the centering guide molding die, and the centering guide 1
It is possible to save the trouble of fixing 7B to the rotor case 10C.

In the second embodiment, the rotor case and the centering guide are made of the above-mentioned materials and shapes. However, the present invention is not limited to this, and in the first embodiment, FIG. 1, FIG. 3 or FIG. It is also possible to apply the rotor case or centering guide shown in FIG.

Further, the rotor case and the centering guide shown in the second embodiment can be applied to the spindle mechanism of the first embodiment.

FIG. 6 shows a third embodiment 25 of the spindle mechanism according to the present invention.

Spindle mechanism 2 shown in the third embodiment
5 differs from the spindle mechanism 1 shown in the first embodiment only in that the centering guide is formed integrally with the rotor case, and therefore only the essential parts are shown in the drawings.

Reference numeral 26 is a centering guide, and the centering guide 26 is the upper surface plate 11 of the rotor case 10D.
Is formed by projecting the central part of the above into a circular projecting shape from above the other parts, and its size is the same as that of the centering guide 17.

A boss portion 13 is formed at the center of the centering guide 26, and the rotary shaft 7 is attached to the boss portion 13.
The upper end of is pressed.

Therefore, according to the fourth embodiment, the centering guide as a dedicated part can be omitted, and the number of parts can be further reduced.

7 and 8 show a fourth embodiment 27 of the spindle mechanism according to the present invention.

Spindle mechanism 2 shown in the fourth embodiment
7 differs from the spindle mechanism 1 shown in the first embodiment only in that the disk mounting surface is formed by a member different from the rotor case.
Also in this embodiment, only the main part is shown in the drawing.

Reference numeral 28 denotes a disk receiving plate formed of a free-cutting material such as aluminum so as to have a flat ring shape, and fixed to the upper surface of the upper surface plate 11 of the rotor case 10 other than the centering guide 17. .

Then, after the assembly of the spindle mechanism 27 is completed, the upper surface 28a of the disk receiving plate 28 is accurately cut to make the upper surface 28a the disk mounting surface.

However, according to the fourth embodiment 27 as described above, the accuracy of the angle of the disk mounting surface 28a with respect to the rotating shaft 7 is irrespective of the processing accuracy of the rotor case 10 and the connecting accuracy with the rotating shaft 7. And smoothness can be accurately expressed.

In the fourth embodiment, the rotor case and the centering guide are made of the above-mentioned materials, shapes, etc., but the present invention is not limited to this. The rotor case or centering guide shown in FIG. 1, FIG. 3, FIG. 4 or FIG. 5 can also be applied.

[0068]

As is apparent from what has been described above, the spindle mechanism of the present invention comprises a turntable on which the central portion of the recording medium disk is removably mounted, and a motor for rotating the turntable. The spindle mechanism is characterized in that the upper plate of the rotor case of the motor is a turntable.

Therefore, the spindle mechanism of the present invention does not require a turntable as a dedicated part,
As a result, the number of parts and the labor of assembly can be reduced, and the cost can be greatly reduced.

Moreover, since the upper plate of the rotor case of the motor serves as a turntable as it is, the dimension in the axial direction can be reduced.

The structure of the motor, the rotor case, the centering guide, and the shapes and materials of the other parts shown in each of the above-mentioned embodiments are merely examples of the embodiment of the present invention. The technical scope of the present invention should not be limitedly interpreted by these.

[Brief description of drawings]

1 shows a first embodiment of a spindle mechanism according to the present invention together with FIGS. 2 and 3, and is a perspective view.

FIG. 2 is a central longitudinal sectional view showing a state in which a recording medium disc is placed.

FIG. 3 is a sectional view showing a modified example of a rotor case.

FIG. 4 is a central longitudinal sectional view showing a modified example of the centering guide.

FIG. 5 is a central longitudinal sectional view showing a second embodiment of the spindle mechanism of the present invention.

FIG. 6 is a central longitudinal cross-sectional view of a main part showing a third embodiment of the spindle mechanism of the present invention.

FIG. 7 shows a fourth embodiment of the spindle mechanism according to the present invention together with FIG. 8, and this figure is a central longitudinal sectional view of a main part.

FIG. 8 is an exploded perspective view of a main part.

FIG. 9 is a side view showing an example of a conventional spindle mechanism with a part cut away.

[Explanation of symbols]

 1 Spindle Mechanism 10 Rotor Case 11 Top Plate (Turntable) 15 Motor 16 Recording Medium Disc 16a Center Hole 17 Centering Guide 10A Rotor Case 20 Spindle Mechanism 10B Rotor Case 17A Centering Guide 10C Rotor Case 23 Motor 17B Centering Guide 25 Spindle Mechanism 10D Rotor Case 26 Circular protrusion (centering guide) 27 Spindle mechanism 28 Free-cutting material 28a Disk mounting surface

Claims (4)

[Claims] 1. A spindle mechanism comprising a turntable on which a central portion of a recording medium disk is detachably mounted, and a motor for rotating the turntable, wherein a top plate of a rotor case of the motor is a turntable. The spindle mechanism that is characterized. 2. The spindle mechanism according to claim 1, wherein a centering guide fitted to the center hole of the recording medium disk is provided on the upper surface plate of the rotor case. 3. The spindle mechanism according to claim 2, wherein the rotor case is integrally formed with a circular protrusion that protrudes upward from the center of the upper surface plate, and the circular protrusion serves as a centering guide. 4. A disk mounting surface is formed by fixing a free-cutting material to the upper surface of a portion of the upper plate of the rotor case other than the centering guide, and cutting the free-cutting material. The spindle mechanism according to claim 2 or 3.