JPH0528609A - Disk chucking device - Google Patents

Abstract

PURPOSE:To provide a disk chucking device capable of chucking a magnetic disk with a small positioning torque even if the positioning force is set in the large amount. CONSTITUTION:A hub table 30 is mounted on a turntable 3 in the contact state with rolling friction, and a metallic hub 25 and a cover 37 for hub table 30 are rotated and slided in one body against the turntable 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk chucking device used for a disk drive device for recording / reproducing information by chucking and rotationally driving an information recording disk having a metal hub. The present invention relates to a disk chucking device suitable for chucking a 3.5 inch diameter floppy disc.

[0002]

2. Description of the Related Art A disk drive device for driving an information recording medium formed in a disk shape (hereinafter, simply referred to as a disk) has various improvements and improvements in response to an increase in recording density and a reduction in size and weight. A device is proposed. One of them is that the turntable is fitted to the spindle shaft, and the disk is recorded / reproduced by rotating the disk by rotating the disk through the drive pin protruding from the disk mounting surface of the turntable and the chuck magnet. There is.

FIG. 6 is a sectional view of the main part of a conventional disk drive device.

In this figure, the disk drive portion of the disk drive device is a disk drive (spindle) motor 1.
And the spindle (rotation) axis 2 of the disk drive motor 1
A turntable 3 fitted to the tip of the spindle shaft 2 and a drive formed on the turntable 3 supported by a spring member (not shown) as a supporting means attached to the lower surface of the turntable 3 in the figure. It is mainly composed of a drive pin 19 inserted into the pin insertion hole 13.

The disk drive motor 1 comprises a rotor portion 5 and a stator portion 6, and a spindle shaft 2 which is inserted into the central shaft portion of the rotor portion 5 and is fixed thereto is freely rotatable by a bearing 7 provided in the stator portion 6. It is combined together by bearing. In the rotor portion 5, a ring-shaped rotor magnet 9 is magnetized in a circular bowl-shaped rotary yoke 8 formed of a soft magnetic material at equal intervals along the circumferential direction.
Is fixed to the stator portion 6, and the rotor magnet 9 of the substrate 10 formed of a soft magnetic material is attached to the stator portion 6.
A plurality of drive coils 11 are circumferentially arranged at a position facing each other. Then, by passing a current through the drive coil 11, a torque is generated in the rotor magnet 9 which is divided and magnetized at equal intervals along the circumferential direction, and a field magnetic flux is generated between the rotor coil 9 and the substrate 10. Then, the rotor portion 5 is rotationally driven with respect to the stator portion 6.

The turntable 3 is formed so as to project above the center of the rotary yoke 8. The turntable 3 has a central hole 12 into which the spindle shaft 2 of the disk drive motor 1 is inserted, and a drive pin 19. A drive pin insertion hole 13 and a spring member (not shown) are provided,
A plastic sheet 15 also called a polyslider for friction is provided at the center of the surface, and a chuck magnet 16 such as a rubber magnet is provided on the surface except for the central hole 12, the drive pin insertion hole 13, and the plastic sheet 15. It is attached. Further, on the back surface of the turntable 3, the tip end of a drive pin 19 fixed to the tip end of a spring member (not shown) projects to the top surface of the turntable 3 through the drive pin insertion hole 13 formed in the turntable 3. There is.

An opening 41 into which the spindle shaft 2 of the spindle motor 1 is press-fitted is provided in a substantially cylindrical inner ring 40 which constitutes a ball bearing of the spindle motor 1 and is located outside the rotary yoke 8. A substantially cylindrical outer ring 42 is concentrically arranged in the. A plurality of balls 43a and 43b are arranged between the outer peripheral portion of the inner ring 40 and the inner peripheral portion of the outer ring 42 so as to be rollable in the circumferential direction in two rows. Inner ring 40
Two annular recesses 44a, 44b are formed on the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the outer peripheral surface of the inner peripheral surface of the outer peripheral surface of the outer peripheral surface of the inner peripheral surface of the outer peripheral surface of
At the position of the outer ring 42 facing the lower part of the annular recess 44b,
An inclined surface 45 is formed over the entire circumference. And
A plurality of balls 43a are arranged in a first row at predetermined intervals so as to be rollable while being in contact with the annular recess 44b and the inclined surface 45.

Further, a preload ring 46 is fitted and disposed on the inner peripheral portion of the upper portion of the outer ring 42, the annular recess 44a and the preload ring 46 are opposed to each other, and a plurality of balls 43b are rotatably supported. The two rows are arranged at a predetermined interval.
Further, the balls 43b of the second row arranged so as to face the annular recess 44a and the preload ring 46, and the annular recess 44b and the inclined surface 45 face each other as described above. The first balls 43a and the first balls 43a are arranged in a zigzag pattern, and this arrangement makes it possible to make the spindle motor 1 thinner.

FIG. 9 shows an example of the disk 23 having a metal hub. A magnetic recording layer is formed on the surface of this type of disk 23, and the disk 23 is housed in a hard case 24a to form a disk cartridge 24.
A metal hub 25, which is formed of a magnetic thin metal plate, is fixed to the center of 3. This metal hub 2
In the center of 5, there is provided a roughly square checking hole 26 through which the tip 2a of the spindle shaft 2 is inserted.
A substantially rectangular positioning hole 27 into which the tip of the drive pin 19 is fitted and engaged is formed in the outer peripheral portion. This type of disk cartridge 24 is typically 3.5
Known as the Inch Flotspie Disk Cartridge.

When the disk cartridge 24 is placed on the turntable 3, the metal hub 25 is attracted by the chuck magnet 16 as shown in the schematic view of FIG. The tip 2a of the shaft 2 is inserted. At this time, the drive pin 19 is pushed down by the metal hub 25 against the elastic force of the spring member 17 toward the side opposite to the disk mounting side, and is pushed into the drive pin insertion hole 13 of the turntable 3, and as shown in FIG. As shown in (a), it is located on the lower surface of the metal hub 25. Next, when the turntable 3 rotates in the direction of the arrow A and the opening positions of the drive pin 19 and the positioning hole 27 coincide with each other, (b) of FIG.
The drive pin 19 is fitted into the positioning hole 27 as shown in FIG. When the turntable 3 further rotates, the drive pin 19 comes into contact with the inner edge 27a on the outer peripheral side of the positioning hole 27, and the elastic force of the spring member 17 causes the entire disk 23 (metal hub 25) to move from the spindle shaft 2 to the drive pin 19 direction. Of the spindle shaft 2 is pressed to the corner portion 26a of the chucking hole 26, which is farthest from the positioning hole 27, for centering. Then, the metal hub 25 and the disk 23 rotate in the direction of arrow A about the spindle shaft 2,
Recording / playback is performed.

[0011]

In the prior art described above, the metal hub 25 of the disk is sucked by the chucking magnet 16 in order to reliably maintain the chucking, as described above. The metal hub 25 needs to slide smoothly on the turntable (plastic check sheet) 3 until the checking is completed.
If the sliding friction is not reduced in this way, the metal hub 25 of the magnetic disk attracted to the chucking magnet 16 and the contact surface of the turntable 3 do not slide relatively lightly, and the positive contact of the rotary yoke 8 does not occur. Since the tightening torque must be increased, miniaturization of the device is hindered. In this case, if the magnetic force of the chucking magnet 16 is reduced to reduce the positioning force, the metal hub 25 of the magnetic disk and the turntable 3 can be slid relatively lightly with a relatively small positioning torque. You can However, in this case, the positioning force of the chucking magnet 16 is reduced, the magnetic disk may not be stably placed on the turntable 3, and the recording / reproducing operation may become unstable.

The present invention has been made in view of the above-mentioned problems of the prior art, and has been made in order to solve the problems. An object of the present invention is to set a magnetic disk in a rotor with a small positioning torque even if a large positioning force is set. An object of the present invention is to provide a spindle motor capable of positioning with respect to a positioning pin.

[0013]

In order to achieve the above object, the present invention provides a support surface for directly supporting a metal hub in the central portion of an information recording disk, and a chuck disposed on the support surface facing the metal hub. A turntable having a magnetic disk,
It is provided with a drive pin protruding from the drive pin insertion hole and supported by supporting means from the side opposite to the information recording disk supporting surface of the turntable, magnetically checking the metal hub of the information recording disk and fitting it in the center of the turntable. In a disk chucking device for rotationally driving an information recording disk by a rotary driving means via a mounted spindle shaft, a hub base having a thrust ball bearing interposed between the turntable and the metal hub is provided. It has a structure mounted on the top.

[0014]

By such means, the magnetic disk is mounted on the hub base, and the hub base rotates integrally with the magnetic disk while rollingly contacts the turntable, thus driving the motor. The turntable rolls with low friction relative to the hub base. In this way
Even if a large positioning force is set, the magnetic disk can be positioned and rotated with respect to the turntable with a small positioning torque for checking.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Here, FIG. 1 is an explanatory front view showing the configuration of the embodiment, FIG. 2 is a plan view of a main part of the embodiment, and FIGS.
5 is a partially enlarged explanatory view showing an operation state of the embodiment,
(A), (b) is a bottom view and a longitudinal cross-sectional view of the hub base of the embodiment, and FIGS. 6 to 9 already described in these figures.
The same parts as those in FIG.

In the embodiment, as shown in FIGS. 1, 3 and 4, a hub base 30 is mounted on the spindle shaft 2 while being loosely inserted therein and in rolling frictional contact with the turntable 3. The hub base 30 has a thrust ball bearing portion A. As shown in FIGS. 5A and 5B, the bearing portion A has one of the balls 32 on the edge portion of the disc-shaped holding plate 31. Holes 33 for projecting and locking the portions are formed at equal intervals, and the center side of the holding plate 31 of each hole 33 is cut and raised to form a holding piece 34 for holding the ball 32. ing. And the ball 32 has these holes 3
3, a part of the ball 32 is protruded, and the holding piece 3
4 and the peripheral edge holding piece 35 formed by bending the edge portion of the holding plate 31 are held rotatably at the positions of the holes 33.

A mounting hole 36 for loosely inserting the spindle shaft 2 is formed at the center of the holding plate 31, and is covered with a ring-shaped cover 37 which serves as a hub base. That is, the cover 37 is arranged on the turntable 3 via the thrust ball bearing portion A, and is prevented from coming off by the stopper ring 39 fitted in the spindle shaft 2. The cover 37 of the hub base 30 has a clearance d with respect to the spindle shaft 2 as shown in FIG. 3, but in the unload state, as shown in FIG. 4, it is provided with a protrusion 16a of the chucking magnet 16. The cover 37 is sucked in a direction away from the drive pin 19. As shown in FIG. 2, the projection 16a is formed by projecting a part of the inner circumference of the chucking magnet 16 toward the center. The configuration of the other parts of the embodiment is similar to that of the conventional disk chucking device which has already been described with reference to FIGS.

Next, the positioning operation of the magnetic disk in the above-mentioned embodiment constructed as above will be described.

The magnetic disk introduced by the disk feeding means (not shown) is rotatably supported by the spindle shaft 2. In the initial state, as described above, the turntable 3 is provided.
The drive pin 19 is not engaged with the engaging hole of the magnetic disk, and the drive pin 19 is pushed to the same surface as the turntable 3 by the surface of the magnetic disk. When a current is applied to the coil 11 from this state and the rotary yoke 8 (turntable 3) starts to rotate, the hub base 30 rolls with respect to the turntable 3 on which the balls 32 of the thrust ball bearing portion A rotate, On the other hand, the hub base 30 and the disk metal hub 25 are integrally moved or stopped. That is, the turntable 3 and the metal hub 25 are relatively moving. Then, when the rotation of the rotary yoke 8 progresses and reaches the position where the drive pin 19 and the positioning hole of the magnetic disk coincide with each other, the drive pin 19 is positioned as described above to bring the magnetic disk into a normal mounting state. Is recorded / reproduced. When the drive pin 19 is engaged with the positioning hole of the magnetic disk, the hub base 30 slightly moves in the direction of the drive pin 19 against the attraction force of the chucking magnet 16a. As described above, in the above-described embodiment, the hub base 30 is in rolling contact with the turntable 3 by the thrust ball bearing portion A, so even if the positioning force by the chucking magnet 16 is set to a large value, The turntable 3 can be rotated by sliding the disk and the hub base 30 with a small positioning torque. For this reason, the chucking operation of the magnetic disk can be performed quickly and stably, and the positioning torque can be small. Therefore, the rotary yoke 8 can be downsized and the entire size can be greatly reduced. become.

In the above-described embodiment, since the metal hub 25 and the hub base 30 of the disk rotate and slide together, the disk hub 25 as in the conventional case.
There is no friction in itself. Further, since the disk hub 25 and the hub base 30 do not rub, it is not necessary to control the surface roughness of the disk hub and the surface material (Teflon sheet or the like) of the hub base 30. In this way, the problem regarding the friction between the disk hub 25 and the hub base 30, which is the maximum weak point for 3.5 "FDD checking, can be cleared. In addition, when the chucking magnet 16 has a high suction force, Conventionally, it was directly affected, but in the above-mentioned embodiment, there is no influence on the positioning torque and the positioning force, and since there is no hysteresis in the positioning torque and the positioning force, extremely efficient positioning force can be obtained. Further, in the above-described embodiment, since the checking portion can be made extremely thin in the thickness direction, it does not hinder the thinning of the spindle motor, and since the structure is simple, mass production is possible and the cost can be reduced. To ensure reliable checking, even for light torque disks, the Is very advantageous also for de. Further, the flywheel only by the force caulking fitted to the shaft, fixing step of press-fitting the adhesive, etc. is not required.

[0021]

As described above, according to the present invention,
Since the magnetic disk is mounted via the hub base that makes rolling frictional contact on the turntable, even if the positioning force is set to a large value, the magnetic disk can be accurately and stably and swiftly applied to the rotor with a small positioning torque. Therefore, it is possible to reduce the size of the entire device.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is an explanatory view of a main part showing a configuration of an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a main part when a magnetic disk according to an embodiment of the present invention is mounted.

FIG. 4 is an explanatory diagram of a main part of the embodiment of the present invention when the magnetic disk is not attached.

FIG. 5 is an explanatory diagram of a hub base according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a configuration of a conventional spindle motor.

FIG. 7 is a schematic sectional view showing a centering operation.

FIG. 8 is an explanatory diagram showing the centering operation as viewed from above.

FIG. 9 is a bottom view of a driven disk cartridge.

[Explanation of symbols]

 2 Spindle shaft 3 Turntable 8 Rotating yoke 11 Coil 16 Checking magnet 19 Drive pin 30 Hub base A Thrust ball bearing

Claims (1)

Claim: What is claimed is: 1. A turntable having a support surface for directly supporting a metal hub in the central portion of an information recording disk, and a chuck magnet arranged on a surface of the support surface facing the metal hub.
Equipped with a drive pin protruding from the drive pin insertion hole and supported by a supporting means from the side opposite to the information recording disk supporting surface of the turntable, the metal hub of the information recording disk is magnetically chucked and mounted at the center of the turntable. In a disk chucking device for rotationally driving an information recording disk by a rotary drive means via a spindle shaft, the hub base having a thrust ball bearing interposed between the turntable and the metal hub is connected to the turntable. A disk chucking device that is mounted on a table.