JPH09161393A - Spindle motor mounting structure of magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a motor chasses having the small number of components without deteriorating the positional accuracy and the horizontality of a turntable by providing attaching parts which are integrally protruded at least three places as attachings to a main chasses on a motor chasses. SOLUTION: A spindle motor assembly 68 is fixed at the prescribed position of a motor attaching face 71 by an adhesion, etc. A motor chasses 70 is made of metallic plate and on which attaching parts 72 are provided at three places by a drawing work and the attaching parts 72 are fixed to prescribed positions on a main chasses 20 by screws 73. Moreover, a spindle motor 60 is inserted into an inner part from the through-hole 23a provided in the bottom plate 23 of the main chasses 20 and the upper face 64 of a turntable 63 is positioned at a prescribed position. Thus, components for attaching the spindle motor 60 to the main chasses 20 are made smaller as compare with the case of using conventional attaching shafts and production processes are made simple and then the reliability of products is also improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure in which, for example, a spindle motor used in a floppy disk drive is attached and fixed to a main chassis, and particularly, a spindle motor in which a rotor of a spindle and a turntable are integrated. Regarding mounting structure.

[0002]

2. Description of the Related Art A magnetic disk device such as a floppy disk drive has a disk rotation drive mechanism for rotating and driving a magnetic disk, a magnetic head for recording or reproducing information on the magnetic disk, and a magnetic head for this magnetic head. A head transfer mechanism configured to be movable in the radial direction of the magnetic disk for positioning on an arbitrary recording track of the magnetic disk. These are mounted on a highly rigid main chassis formed by aluminum die casting or sheet metal processing. 4 and 5 show first and second examples of a conventional spindle motor mounting structure.

FIG. 4 shows a conventional spindle motor mounting structure in a floppy disk drive, which is not shown in the main chassis 1 in this figure.
A cartridge holder for detachably supporting the magnetic disk, a magnetic head for recording or reproducing information on the magnetic disk, and a head transfer mechanism for transferring the magnetic head in the radial direction of the disk are mounted. . The spindle motor 2 is composed of a rotor 2a and a control circuit board 2b. The control circuit board 2b generally has an insulating layer coated on the surface of an iron plate, an electronic circuit is printed on the surface, and electronic components for controlling the rotation of the spindle motor 2 as well as a stator coil (not shown) are installed. Has been done.
A turntable 3 is integrally provided on the rotor 2a, and a flexible disk 7 having a metal hub 6 is placed on the upper surface of the turntable 3 so as to rotate together with the rotor 2a.

To mount the spindle motor 2 on the main chassis 1 in the prior art as described above, first, the spindle motor 2 is fixed to the motor chassis 4 by adhesion or the like, and in this state, the motor chassis 4 is mounted on at least three mounting shafts 5. It was performed by fixing to the main chassis 1 via. The mounting shaft 5 is formed with a screw portion 5a on the upper side and engages with a screw receiving hole provided on the motor mounting portion 1a of the main chassis 1, and a screw receiving hole 5b is formed on the lower side, and the screw 8 is used to form the motor chassis. 4 is fixed. The spindle motor 2 can accurately determine the mounting position and the levelness with respect to the main chassis 1 by the three mounting shafts 5, and the turntable 3 passes through the motor hole 1c provided at the bottom of the main chassis 1. It is installed accurately and horizontally at a predetermined position inside. Therefore, it is possible to rotate the flexible disk 7 in a horizontal state.

Next, a second example of the conventional spindle motor mounting structure will be described with reference to FIG. It should be noted that the description of the members that are substantially the same as those already described in FIG. 4 will be omitted. The difference from the first conventional technique shown in FIG. 4 is that the first conventional technique uses the mounting shaft 5, while the second conventional technique uses the mounting shaft 5.
In the prior art, the motor chassis 4 is directly screw-fixed to the motor mounting portion 9a provided integrally with the main chassis 9.

[0006]

However, in such a conventional spindle motor mounting structure of the magnetic disk device, in the first example, the motor chassis 4 is used.
Although the mounting position accuracy is good, since the mounting shaft 4 is formed as a separate body, there are problems that the number of parts is large, the assembly process is complicated, and the production cost is increased.
Further, in the second conventional example, while it is advantageous in cost,
Since the mounting portion 9a has to be integrally formed on the large main chassis 9, the processing accuracy is poor, and the mounting position accuracy of the motor chassis 4 is deteriorated.

Therefore, the present invention provides a spindle motor mounting structure for a magnetic disk drive, which has a simple manufacturing process and a low production cost, by reducing the number of parts without deteriorating the positional accuracy and levelness of the turntable. The purpose is to do.

[0008]

In order to achieve the above object, the present invention provides a metallic center hub having a main chassis, a spindle hole, and a drive pin hole eccentric to the spindle hole. A magnetic disk, a cartridge holder that removably supports a disk cartridge that rotatably accommodates the magnetic disk, a spindle that engages with the spindle hole, a drive pin that engages with the drive pin hole, and the center hub. A turntable including a chucking magnet that attracts magnetically, a magnetic head for recording or reproducing information on the magnetic disk, and a head transfer for moving the magnetic head in the radial direction of the magnetic disk. A mechanism and a spindle motor including a rotor integrally formed with the turntable; In a spindle motor mounting structure of a magnetic disk device having a motor chassis for fixing a pindle motor to a predetermined position of the main chassis, the spindle motor is bonded to a motor chassis formed by at least three mounting portions integrally protruding. And the like, and the motor chassis in this state is fixed to the main chassis through the mounting portion.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described.
This will be described together with the illustrated example. FIG. 1 shows a disk cartridge used in a floppy disk drive according to the present invention, FIG. 2 shows a sectional view of an essential part of the floppy disk drive according to the present invention, and FIG. 3 shows an exploded perspective view of the floppy disk drive according to the present invention. Show. Hereinafter, FIGS. 1 to 3
Based on the above, embodiments of the present invention will be described in detail.

In FIG. 1, reference numeral 10 denotes a flexible magnetic disk, and a center hub 1 made of metal is provided at the center thereof.
1 is provided and is made of a hard synthetic resin protective case 12
The disk cartridge 13 is rotatably accommodated in the disk cartridge to form a disk cartridge 13. The center hub 11 has a spindle hole 14 at the center of rotation and a drive pin hole 15 at a position offset from the center of rotation.

In FIG. 3, the main chassis 20 is a stamped product of a metal plate, and has side walls 21 on both sides and a rear wall 22 provided opposite to the side on which the disc cartridge 13 is inserted.
It has a bottom plate 23. Reference numeral 30 denotes a slide plate, groove cams 31 are provided on both sides of the slide plate, and the slide cams are provided so as to be reciprocally slidable in the insertion direction of the disc cartridge 13. Reference numeral 40 denotes a cartridge holder, which supports the disc cartridge 13 in an attachable / detachable manner, and is provided with a vertical groove 24 provided on the side walls 21 on both sides of the main chassis 20 and a pin 41 engaging with a groove cam 31 of the slide plate 30. ing. The disk cartridge 13 has a cartridge insertion port 4
2 is inserted, the slide plate 30 releases the lock mechanism (not shown) and slides toward the side opposite to the insertion direction of the disc cartridge 13 by the biasing spring (not shown), and the pin 41 Moves up and down in the vertical groove 24 along the groove cam 31. Then, the disc cartridge 13 is set to the lower drive position. When removing the disc cartridge 13, the slide plate 30 is pushed in the opposite side of the disc insertion direction, so that the holder 4
It is possible to discharge by moving 0 to the upper mounting position.

Reference numeral 51 denotes a magnetic head, which rotates when the disk cartridge 13 is at the drive position.
Information is recorded or reproduced by sliding contact with the recording surface of 0. The magnetic head 51 is attached to a carriage 52, and the carriage 52 engages with a lead screw 54 connected to a rotor of a stepping motor 53 fixed to the rear wall 22 so that the carriage 52 can be moved in the radial direction of the magnetic disk 10. It is configured.

A spindle motor 60 is composed of a rotor 61 having a rotor magnet 61a therein and a stator coil (not shown) mounted on a control circuit board 62 for controlling the rotation of the spindle motor 60. . The rotor 61 is formed integrally with the turntable 63. Disk mounting surface 64 of the turntable 63
Is provided with a spindle 65 at the center of its rotation, a drive pin 66 at a position eccentric to the spindle 65, and a chucking magnet 67 around these. Disk cartridge 13
Is attached to the drive position, the chucking magnet 67 magnetically attracts the center hub 11 to bring it into close contact with the disk mounting surface 64. Then, the spindle 65 and the drive pin 66 engage with the spindle hole 14 and the drive pin hole 15, respectively, and the magnetic disk 10 is rotationally driven at a predetermined position in the apparatus. In the control circuit board 62, an insulating layer is formed on the surface of a metal plate made of iron, and in addition to the stator coil, electronic parts such as a motor drive IC and a circuit electrically connecting these are formed. The spindle motor 60 constitutes a spindle motor assembly 68 together with the control circuit board 62,
In the manufacturing process, it is handled as one single item.

Reference numeral 70 denotes a motor chassis which is a characteristic configuration of the present invention, and the spindle motor assembly 68 is fixed to a predetermined position of the motor mounting surface 71 by adhesion or the like. The motor chassis 70 is made of a metal plate, and mounting portions 72 are formed at three points by drawing. The mounting portion 72 is fixed to a predetermined position of the main chassis 20 with a screw 73. As shown in FIG. 2, the spindle motor 60 is inserted inside through a through hole 23a provided in the bottom plate 23 of the main chassis 20, and the upper surface 64 of the turntable 63 is horizontally positioned at a predetermined position. Although the control circuit board 62 and the motor chassis 70 are handled as separate bodies in this embodiment, it goes without saying that they may be integrally formed and used.

[0015]

As described above, according to the present invention, in order to attach the spindle motor to the main chassis, the metal motor chassis is provided with three attachment portions integrally by drawing and is fixed by screws. Therefore, compared to the case where the mounting shaft is used, the number of parts can be reduced, the production process can be simplified, the reliability of the product can be improved, and the production cost can be reduced. Further, when the mounting portion is provided integrally with the main chassis, since the main chassis is a large product, the dimensional accuracy of the mounting portion is poor and the position accuracy and levelness of the turntable are poor. It is possible to eliminate such a defect.

[Brief description of the drawings]

FIG. 1 is an external view showing a disc cartridge according to the present invention.

FIG. 2 is a sectional view of a main part of a floppy disk drive according to the present invention.

FIG. 3 is an exploded perspective view of a floppy disk drive according to the present invention.

FIG. 4 is a sectional view of an essential part showing a first example of a conventional spindle motor mounting structure.

FIG. 5 is a cross-sectional view of essential parts showing a second example of the conventional spindle motor mounting structure.

[Explanation of symbols]

 10 Magnetic Disk 11 Center Hub 12 Protective Case 13 Disk Cartridge 14 Spindle Hole 15 Drive Pin Hole 20 Main Chassis 21 Sidewall 22 Rear Wall 23 Bottom Wall 23a Through Hole 30 Slide Plate 31 Groove Cam 40 Cartridge Holder 41 Pin 42 Cartridge Insertion Port 51 Magnetic Head 52 Carriage 53 Stepping motor 54 Lead screw 60 Spindle motor 61 Rotor 61a Rotor magnet 62 Control circuit board 63 Turntable 64 Disk mounting surface 65 Spindle 66 Drive pin 67 Chucking magnet 68 Spindle motor assembly 70 Motor chassis 71 Motor mounting surface 72 mounting part 73 screw

Claims (1)

[Claims] 1. A magnetic disk having a metallic center hub having a main chassis, a spindle hole, and a drive pin hole located at a position offset from the spindle hole, and a disk cartridge rotatably accommodating the magnetic disk. A detachable support cartridge holder, a spindle that engages with the spindle hole, a drive pin that engages with the drive pin hole and a chucking magnet that magnetically attracts the center hub; A magnetic head for recording or reproducing information on a disk, a head transfer mechanism for moving the magnetic head in the radial direction of the magnetic disk, and a spindle including a rotor integrally formed with the turntable. Fix the motor and this spindle motor in place on the main chassis. In a spindle motor mounting structure of a magnetic disk device having a motor chassis for fixing, the motor chassis has mounting portions formed integrally at least at three locations for mounting to the main chassis. Spindle motor mounting structure for magnetic disk drive.