JPH0541012A - Disk chucking mechanism - Google Patents

Abstract

PURPOSE:To reduce the space occupied by a chucking mechanism and to make a disk device thinner by providing a protective coating on a part or full area of the upper surface of a chucking magnet. CONSTITUTION:A rotor 112 of spindle motor is pressed and fixed in a groove 120a of spindle 120, and the chucking magnet 132 is stuck on the upper surface of rotor 122. On the upper surface of this magnet 132, a prescribed sheet is stuck so as to have a good sliding. So, although a disk hub, when it is tilted, is possibly brought into contact with the magnet 132, the friction is reduced at this time and the generation of magnetic powder due to a rupture is prevented. By forming such a chucking structure, the space of the chucking part can be reduced without requiring members such as an usual fulcrum, various kinds of springs, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for chucking a spindle motor of a disk device,
More specifically, it relates to a JIS 90 mm flexible disk cartridge.

[0002]

2. Description of the Related Art The conventional technique is as follows.
No. 7, gazette and as shown in FIG.
A disk chucking mechanism has been known in which a chucking magnet 4 for attracting and fixing the disk hub 3 is attached to a rotating plate 2 that rotates together with the disk hub 3, and the disk hub 3 is attracted and fixed.

FIG. 6 is a sectional view of a conventional disk chucking mechanism.

[0004]

In the above-mentioned prior art,
When attempting to reduce the thickness of the disk drive device, a space in the thickness direction (vertical direction in the drawing) of the rotary disk 2 attached to the spindle 1 cannot be secured, and it is difficult to design the disk chucking mechanism.

Therefore, the present invention is intended to reduce the space occupied by the disk chucking mechanism in view of the above-mentioned conventional problems, to simplify the disk chucking mechanism and to further reduce the thickness of the disk device. To aim.

[0006]

In order to solve the above problems, the disk chucking mechanism of the present invention engages with the central hole of a metallic disk hub fixed to the central portion of the disk housed in the jacket. A spindle, a rotating plate fixed to the spindle, a chucking magnet provided on the rotating plate for attracting the disk hub, and a substantially rectangular shape provided on the rotating plate at a position eccentric from the center of the disk hub. In a disk chucking mechanism consisting of a drive pin that engages in a drive hole and rotationally drives a disk, a part of the upper surface of the chucking magnet,
Alternatively, it is characterized in that a protective coating is provided on the entire surface.

[0007]

In the disk chucking mechanism configured as described above, by making the thickness of the disk chucking mechanism as thin as possible, the distance between the receiving surface of the disk hub and the chucking magnet becomes shorter, and the disk hub becomes the chucking magnet. Even if the upper surface is slid and rubbed, normal chucking can be performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a disk chucking mechanism of a spindle motor according to the present invention. 2 is an exploded perspective view of the spindle motor of the present invention.

Referring to FIG. 1, a disk hub 135 made of metal and bonded to the center of the disk housed in the jacket.
There is a spindle 120 which engages with the center hole (shown in FIG. 5) and performs center positioning, and a rotor 122 of a spindle motor for driving the disk is press-fitted and fixed. Due to the recent demand for thinner computers,
It is a common recognition among those involved in the design of disk devices that the thinnest part of the disk device is the spindle motor, which is the part that is required to be the thinnest. Therefore, the thickness of the rotor 122 of the spindle motor is as thin as the design allows, and in this embodiment, a 0.5 mm thick iron plate is used. Even if such a thin iron plate is press-fitted into the spindle 120, since the fitting length in the axial direction is short,
The plane runout of the rotor 122 with respect to the spindle 120 cannot be secured. Therefore, the spindle 120 is provided with a groove 120a for an E-shaped retaining ring, and the groove 120a has an E-shaped groove.
A retaining ring 121 is set. Since the groove 120a is processed by, for example, a lathe or the like, it is possible to minimize the shake with respect to the spindle 120. And in this embodiment,
Since press-fitting is performed until the rotor 122 comes into close contact with the upper surface of the E-shaped retaining ring, if there is no unevenness in the thickness of the E-shaped retaining ring,
The rotor 122 has high accuracy similar to the runout accuracy of the groove 120a.
Can be press-fitted.

Since high deflection accuracy can be secured in this way,
The upper surface of the rotor 122 can be directly used as the receiving surface of the disk hub 135, and the disk and the recording / reproducing head can be
Good contact can be secured.

A rotor magnet 123, which adheres to the rotor 122 and generates a torque of the motor, has a protrusion 123a at one position on the outer peripheral portion, positions the rotor 122 with the notch 122a, and magnetizes two poles. A magnetic sensor (not shown) generates a signal (referred to as an index signal) once per one rotation of the motor. This two-pole magnetization is in phase with the drive magnetization magnetized on the inner surface of the rotor magnet 123, and a stronger magnetic force can be obtained.

Further, the lower surface of the rotor magnet 123 in the figure (the surface facing the motor substrate 124 in FIG. 2) is magnetized for speed detection in multiple poles. By thus partially magnetizing the rotor magnet 123, one magnet can be effectively used.

In FIG. 2, a detection switch 12 for detecting that a jacket (not shown) accommodating a disk is set at the recording / reproducing position on the motor substrate 124.
5. The operation indicator lamp connector 126 is attached. A housing 127 and a stator 128 around which a coil is wound are fixed to the center of the substrate by three countersunk screws 129.

The housing 127 has a metal bearing 130.
And the ball bearing 131 are press-fitted, and the outer diameter of the ball bearing 131 is equal to that of the metal bearing 130.
The outer ring of the ball bearing bearing 131 receives the pressure from the side of the ball bearing bearing 131. In this embodiment, the housing 127 is made of plastic, so that the bearing can be easily press-fitted and the adverse effects (deformation and scratches) due to the press-fitting of the bearing can be minimized. is there. The aforementioned spindle 120 is inserted into these bearings.

Referring back to FIG. 1, chucking will be described. A chucking magnet 132 is attached to the upper surface of the rotor 122, and a hole is partially formed so that the rotor surface can be seen. Inside this hole, a chucking lever 133 for engaging with the drive hole of the disk hub 135 and rotationally driving and centering the disk is attached.

The chucking lever 133 is the rotor 12
2 and the pivoting fulcrum 122b and the chucking lever 1
The rotor 133 is attached to the groove 133b provided in the drive pin portion 133a of the rotor 33 by the rotation guide portion 122c which is a part of the rotor 122.

Rotating fulcrum 1 of chucking lever 133
A disengagement prevention lever portion 133c provided near 33d wraps around the lower part of the disengagement prevention claw 122d of the rotor 122, and prevents the rotation fulcrum portion 133d from being disengaged due to an external impact or the like. The chucking lever 133 has an integral structure of plastic, and the detachment prevention lever portion 133c
Has a structure in which it is slipped under the disengagement preventing claw 122d during assembly. Further, a coating 122e of a material having a good slidability is formed on the upper surface of the rotor 122 for receiving the disk hub 135 (shown in FIG. 5) so as to receive the disk hub 135. This coating 122e
Is coated circumferentially coaxially with the spindle 120.

The chucking of this embodiment will be described in more detail with reference to FIGS. 3, 4 and 5. FIG. 3 shows FIG.
4 is a plan view of FIG. 4, FIG. 4 is a cross-sectional view of AOA of FIG. 3, and FIG. 5 is a cross-sectional view of BOO′B of FIG. In FIG. 3, the hatched portion of the chucking magnet 132 is magnetized. The disk hub 13 is attached to the center of the spindle 120.
The suction force of No. 5 is uniform. The chucking lever 133 has a hole 122 formed in the rotor 122.
It is constructed so that it can be rotated by a necessary amount within the f centering around the rotation fulcrum 122b. On the other hand, in the thrust direction of the drive pin portion 133a of the chucking lever 133, as shown in FIGS. 3 and 4, the drive pin portion 13 of the chucking lever 133 is used.
Since the rotation guide portion 122c, which is a part of the rotor 122, is engaged with the groove 133b provided in 3a, the structure is such that it cannot move in the thrust direction (arrow 139 in FIG. 4).

With such a structure, when the disk hub 135 (shown by the alternate long and short dash line in the figure) is attracted by the chucking magnet 132 as shown in FIG. 5, the drive hole and the drive pin of the disk hub are initially set. Part 133
The disk hub 135 does not align with the position of a
Although it leans on the upper surface of 3a, the disk hub 135 is set by the rotation of the spindle motor so that the drive pin portion 133a and the drive hole of the disk hub 135 are aligned.

At this time, the disk hub 135 and the upper surface of the drive pin portion 133a may slide and wear. Therefore, the upper surface of the drive pin portion 133a is slightly inclined so that the area in contact with the disk hub 135 is small. It is configured to be wider. The optimum inclination was 2 ° ± 1.5 °. Further, the disk hub 135 may come into contact with the chucking magnet 132 when tilted. If a material having a large friction coefficient such as a rubber magnet is used for the chucking magnet 132, the disk hub 135
By contacting the chucking magnet 132,
The frictional force acts on the disc hub 135, the chucking magnet 132 and the disc hub 135 rotate together,
A situation occurs in which the drive pin portion 133a cannot be engaged with the drive hole of the disc hub 135 forever. Therefore, the sheet 134 is attached to the upper surface of the chucking magnet 132 so as to have good slidability. This can prevent the generation of magnetic particles due to the sliding, in addition to the friction between the disk hub 135 and the chucking magnet 132, and can also improve the reliability of the disk device.

Needless to say, the same effect can be obtained by coating the chucking magnet 132.

At this time, in order to reduce the inclination of the hub 132 and perform stable chucking, the engagement amount 140 between the drive pin portion 133a and the disk hub 135 in FIG.
Was 0.7 mm or less in the experiment.

Further, with the above-mentioned chucking structure, the space of the chucking portion can be effectively utilized, and the outer diameter of the motor rotor can be 40 mm and the thickness from the bottom surface of the motor substrate to the upper surface of the rotor can be 4 mm.

The disk chucking mechanism does not require dedicated members such as a fulcrum, a drive pin, and various springs, and can be a chucking lever integrated with a plastic, which is very simple in structure and improves reliability. And the cost can be reduced.

[0025]

According to the disk chucking mechanism of the present invention,
As described above, by providing a protective coating on part or all of the upper surface of the chucking magnet that attracts the disk hub provided on the rotating plate fixed to the spindle,
The space of the disk chucking mechanism can be made small, and the generation of magnetic particles from the chucking magnet can be prevented.It is possible to improve the reliability of the disk device and reduce the size and thickness of the motor. This leads to the great effect of achieving ultra-miniaturization, thinning, and high reliability.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a disk chucking mechanism of a spindle motor according to the present invention.

FIG. 2 is an exploded perspective view of a spindle motor according to the present invention.

FIG. 3 is a plan view of FIG.

FIG. 4 is a sectional view taken along the line AOA in FIG.

FIG. 5 is a sectional view taken along the line BOO′B of FIG.

FIG. 6 is a cross-sectional view of a conventional disc chucking mechanism.

[Explanation of symbols]

 120 Spindle 122 Rotor 122b Rotational fulcrum 122c Rotational guide part 122d Detachment prevention claw 132 Chucking magnet 133 Chucking lever 133a Drive pin part 133b Groove 133c Detachment prevention lever part 133d Rotational fulcrum part 134 Sheet 135 Disc hub

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shirase Go straight 5-8-45 Enami, Yono City, Saitama Prefecture Japan Servo Co., Ltd. Saitama Factory

Claims (2)

[Claims] 1. A spindle engaged with a central hole of a metallic disc hub fixed to the center of a disc housed in a jacket, and a rotary plate fixed to the spindle.
A chucking magnet that is provided on the rotary plate to attract the disk hub, and a drive pin that is provided in the rotary plate and that engages in a substantially rectangular drive hole provided at a position eccentric from the center of the disk hub to drive the disk to rotate. 7. A disk chucking mechanism comprising the above-mentioned chucking magnet, wherein a protective coating is provided on part or all of the upper surface of the chucking magnet. 2. The disk chucking mechanism according to claim 1, wherein the rotary plate is a rotor of a spindle motor that rotationally drives the disk.