JPH05128778A - Recording medium driving device - Google Patents

Abstract

PURPOSE:To surely fix peripheral media and to prevent the trouble by dislodgment of dust, etc., sticking to a tacky adhesive attached and provided on a sealing member and the evaporation of a volatile component by decreasing the angle of deflection of a clamping member by tightening. CONSTITUTION:A rotor hub 16 has a small-diameter annular surface 26 around a screw hole 22 opened in the central part of a base part 18 of the rotor hub and has a recessed part 28 of the base part in its outer peripheral part. The small-diameter annular surface 26 and the circular flat plate part 52 of a clamping member 50 are brought into pressurized contact with each other by screwing with a screw 62. The angle of deflection generated outward the direction isolating from a rotor hub 16 toward outward in the circular flat plate part 52 decreases as the rotor hub 16 and the clamping member 50 do not come into contact with each other in the recessed part 28 of the base part. The sealing part is stuck to the rear of the base part of the rotor hub by the tacky adhesive of a thermosetting type attached and provided to and on the front surface thereof. The tacky adhesive is cured by heating to fix the sealing member, by which the screw hole penetrating the base part is tightly sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium driving device for holding a recording medium fixedly on a rotor hub and driving it to rotate.

[0002]

2. Description of the Related Art FIG. 3 shows a clamp of a recording medium driving device for rotationally driving a recording medium such as a hard disk a fixedly held on an outer peripheral portion of a bowl-shaped rotor hub b of a spindle motor. The member c is fixed to the central portion of the base portion of the rotor hub b by a tightening means such as a screw d so that the hard disk a or the like is pressed and fixed by the clamp member c.

In this case, the clamp member c is fastened to the rotor hub b by the screw d, and the clamp member c is outwardly centered on the portion fastened by the screw d and is separated from the rotor hub b by the deformation caused by the tightening. Deflection occurs in the direction to do. That is, based on FIG. 3, the clamp member c bends upward in the radial direction and the lower end portion of the outer periphery of the clamp member c, that is, the upper surface of the inner peripheral portion of the uppermost hard disk a, should be pressed downward. May be displaced upward and the pressing force against the hard disk a may be insufficient, resulting in uncertain fixation and holding of the hard disk a.

On the other hand, the base portion of the rotor hub is provided with a screw hole for fixing the clamp member to the rotor hub and a hole for preventing rotation of the rotor hub when mounting a hard disk or the like as a through hole. Many. This is because the surface treatment liquid and the like are evenly distributed by forming the through holes, and rust and the like are surely prevented.

However, if lubricant fine particles or dust inside the rotor hub, that is, inside the motor, leaks to the outside through such a through hole, for example, the disk chamber of the hard disk drive may be contaminated, which is inconvenient. It has been practiced to seal a through hole by fixing a seal member such as an aluminum plate having an adhesive on one surface to the inside of the rotor hub with the adhesive.

However, even in such a case, dust such as cutting chips adheres to the portion of the adhesive facing the through hole, and is removed after the device is assembled, or the volatile components contained in the adhesive are not removed. When it is turned into dust, dust or gas may contaminate the inside of the disc or the like through the through hole.

The present invention has been made in view of the above problems existing in the prior art, and an object of the present invention is to reduce the bending angle of the clamp member due to tightening so that A recording medium driving device capable of preventing the pressing force applied to the recording medium from becoming insufficient and securely fixing the recording medium, and a device that adheres to the adhesive after the device is assembled or is being used. It is an object of the present invention to provide a recording medium drive device that can prevent the inconvenience caused by the separation of dust and the like and the vaporization and emission of volatile components contained in an adhesive.

[0008]

In order to achieve the above object, in a recording medium driving apparatus of the present invention, a clamp member for fixing and holding a recording medium on the outer peripheral portion of a bowl-shaped rotor hub has a central portion of the base of the rotor hub. A recording medium driving device in which the recording medium is pressed and fixed by a clamp member by being tightened to a portion by a tightening means, and an outer peripheral portion of the tightening means in a portion where the clamp member and the rotor hub face each other. Of the clamp member and / or the rotor hub, the annular portion of the clamp member and / or the rotor hub on the outer peripheral side of the pressure contact portion does not contact the clamp member and the rotor hub. It is supposed to be formed in.

In order to achieve the above object, the recording medium driving device of the present invention is such that a through hole provided in a rotor hub for holding and rotating a recording medium is provided with a seal member fixed to the rotor hub. In a hermetically-sealed recording medium driving device, it is assumed that the seal member is fixed to the rotor hub by heat curing of a thermosetting adhesive attached to the seal member.

[0010]

According to the first aspect of the invention, the clamp member is outwardly centered on the portion tightened by the tightening means, and is deformed by the tightening so that the clamp member is bent away from the rotor hub. This bending angle is reduced by forming the annular portion on the outer peripheral side of the annular press contact portion where the clamp member and the rotor hub are in pressure contact with each other, in the concave portion where the clamp member and the rotor hub are not in contact with each other. Therefore, it is possible to prevent the pressing force applied from the clamp member to the recording medium from becoming insufficient due to the bending.

According to the second aspect of the present invention, since the adhesive agent attached to the seal member that is fixed to the rotor hub and seals the through hole is hardened by heating, dust and the like to the adhesive agent at the portion facing the through hole is hardened. Adhesion and its detachment are prevented. In addition, since the volatile components contained in the pressure-sensitive adhesive are released in advance by the heat curing, it is possible to prevent the volatile components from being vaporized and diffused later.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view of a recording medium driving device as one embodiment of the present invention.

Reference numeral 10 is a bracket. Bracket 10
A cylindrical bearing holding portion 12 is erected at the center of the bearing holding portion 12, and an annular bracket recess 14 is formed on the outer peripheral portion of the base portion of the bearing holding portion 12.

Reference numeral 16 is a bowl-shaped rotor hub. The base portion 18 of the rotor hub 16 includes a disc-shaped portion 19 and a base portion of the rotating shaft 20 that is press-fitted and fixed to the center portion of the disc-shaped portion 19 so as to project inward of the rotor hub 16, that is, downward in FIG. 1. It is constituted by the end portion 20a. 22
Is a screw hole provided in the central portion of the rotary shaft 20 and opens on the upper surface of the rotary shaft 20. Around the screw hole 22 on the upper surface of the base portion 18, a small-diameter annular surface 26 having an outer diameter equal to that of the rotating shaft 20 is provided, and the outer diameter of the small-diameter annular surface 26 is smaller than that of the bearing holding portion 12. A slightly smaller annular base recess 28 is provided. A large-diameter annular surface 30 is provided on the outer peripheral portion of the base recess 28, and the small-diameter annular surface 2 is provided.
6 and the large diameter annular surface 30 form a plane substantially perpendicular to the axis. An annular overhanging portion 34 is formed on the outer peripheral side of the lower end portion of the outer peripheral wall 32 of the rotor hub 16.

The rotary shaft 20 is rotatably supported by the bracket 10 via upper and lower ball bearings 36 and 38 arranged inside the bearing holder 12. Bearing holder 12
An inward projection 40 is provided at an intermediate position between the upper and lower sides, and this functions as a spacer between the upper and lower ball bearings 36 and 38. The lower opening of the bearing holder 12 has the seal member 4
It is sealed by 2.

Reference numeral 44 is a stator core fixed to the outer peripheral portion of the bearing holding portion 12, and 46 is a stator coil wound around the stator core 44. A cylindrical rotor magnet 48 is fixed to the inner peripheral surface of the outer peripheral wall 32 of the rotor hub 16, and the rotor magnet 48 faces the stator core 44 with a radial gap.

Reference numeral 50 is a clamp member. The clamp member 50 has an insertion hole 54 in the central portion of the circular flat plate portion 52 and an annular downward protrusion 56 in the outer peripheral portion. A hard disk 58, which is an example of a recording medium, is provided on the upper surface of the annular overhanging portion 34 of the outer peripheral wall 32 of the rotor hub 16.
Three pieces are externally fitted with the annular spacer 60 interposed therebetween. The screw 62 is passed through the insertion hole 54 of the clamp member 50 and the screw hole 22.
By tightening the clamp member 50 against the rotor hub 16 by screwing the hard disk 58 and the annular spacer 60, the hard disk 58 and the annular spacer 60 are clamped between the upper surface of the annular protrusion 34 and the lower surface of the lower protrusion 56 of the clamp member 50. It is fixed. The screw 62 and the screw hole 22 are an example of tightening means.

The outer peripheral portion (press contact portion) of the insertion hole 54 on the lower surface of the circular flat plate portion 52 of the clamp member 50 and the rotor hub 1
The small-diameter annular surface 26 (pressure contact portion) is in pressure contact with each other by tightening with the screw 62, but the rotor hub 16 and the clamp member 50 are not in contact with each other in the base recess 28 in the outer peripheral portion of the small-diameter annular surface 26. .. Due to the deformation of the circular flat plate portion 52 of the clamp member 50 due to the tightening, the circular flat plate portion 52 is bent outward in a direction away from the rotor hub 16, that is, in the upper left direction in FIG. Is reduced because the rotor hub 16 and the clamp member 50 are not in contact with each other in the base recess 28. Therefore, the clamp member 50 is flexed.
The insufficient pressing force from the hard disk 58 to the hard disk 58 is prevented, and the hard disk 58 is securely fixed.

The recess formed on the outer peripheral side of the press contact portion is
It may be provided on the lower surface side of the clamp member 50, or may be provided on both the clamp member 50 and the rotor hub 16. However,
If the rotor hub 16 is provided with a recess, the bottom surface of this recess can be used as a contact surface when the rotary shaft 20 is press-fitted into the rotor hub 16, thereby avoiding damage to the top surface of the base portion 18. Further, the recessed portion provided in the rotor hub 16 can also be used to prevent rotation when the hard disk 58 is mounted on the rotor hub 16.

Reference numeral 66 is an extraction hole provided in the bracket 10. Reference numeral 68 denotes a flexible circuit board, one end portion 68a of which is fixed to the bottom surface of the bracket recess 14 and is drawn out below the bracket 10 through the drawing hole 66. The gap between the flexible circuit board 68 and the extraction hole 66 is filled with a sealant 70 and sealed. 7
Reference numeral 2 is an adhesive double-sided tape attached to the upper surface of the one end portion 68a of the flexible circuit board 68 fixed to the bottom surface of the bracket recess 14. Instead of the adhesive double-sided tape 72, an adhesive may be directly provided on the upper surface of the one end portion 68 a of the flexible circuit board 68. 74 is a lead-out portion of the stator coil. The drawn-out portion 74 is temporarily attached to the double-sided adhesive tape 72, and the flexible circuit board 68.
Is soldered to the terminals. The easy-moving pull-out portion 74 is temporarily attached and fixed to the adhesive double-faced tape 72 to facilitate soldering.

FIG. 2 is a half sectional view of a recording medium driving apparatus as another embodiment of the present invention. In this embodiment, the base portion 82 of the rotor hub 80 is provided with a screw hole 84 penetrating in the axial direction.

Reference numeral 86 is a seal member. Seal member 86
Is, for example, a plate or sheet made of a material such as plastic such as polyethylene terephthalate or a metal such as stainless steel or aluminum.

A thermosetting adhesive 88 is attached to the upper surface of the seal member 86. With the sealant 86 adhered to the lower surface of the base portion 18 of the rotor hub 16 by the adhesive 88, the sealant 86 is fixed to the rotor hub 16 by heating to cure the sealant 86 and seal the screw hole 22. It is sealed by the member 86.

Since the adhesive 88 is hardened by heating, adhesion of dust and the like to the portion of the adhesive 88 facing the screw hole 84 is prevented, and the adhesive 88 is hardened by heat.
Volatile components contained in are released in advance. Therefore, for example, after assembly of the device or during use of the device, dust or the like adhering to the adhesive 88 is released, or volatile components contained in the adhesive 88 are vaporized and diffused, so that the disk of the hard disk drive device Inconveniences such as indoor pollution can be prevented. Other than the above description, it is the same as that of FIG.

[0025]

According to the recording medium driving device of the first aspect, the annular portion on the outer peripheral side of the annular press contact portion where the clamp member and the rotor hub are in pressure contact with each other is formed in the concave portion where the clamp member and the rotor hub are not in contact with each other. Therefore, it is possible to prevent the bending angle of the clamp member due to the tightening from being reduced and the pressing force applied from the clamp member to the recording medium becomes insufficient, so that the recording medium can be securely fixed.

In the recording medium driving device of the second aspect, since the adhesive attached to the seal member is hardened by heating, the volatile component contained in the adhesive is released beforehand, and the portion facing the through hole is formed. It is possible to prevent dust and the like from adhering to the adhesive. Therefore, for example, after the device is assembled, or while the device is in use, dust or the like adhering to the adhesive is released, or volatile components contained in the adhesive are vaporized and diffused. In some cases, inconveniences such as contamination of the disk interior of the hard disk drive can be prevented.

[Brief description of drawings]

FIG. 1 is a half cross-sectional view of a recording medium driving device.

FIG. 2 is a half cross-sectional view of another recording medium driving device.

FIG. 3 is a half sectional view of a conventional recording medium driving device.

[Explanation of sign]

 16 rotor hub 22 screw hole 26 small diameter annular surface 28 base recess 50 clamp member 58 hard disk 62 screw 80 rotor hub 84 screw hole 86 seal member 88 adhesive

Claims (2)

[Claims] 1. A clamp member for fixing and holding a recording medium on an outer peripheral portion of a bowl-shaped rotor hub is clamped to a central portion of a base portion of the rotor hub by a clamping means, so that the recording medium is pressed and fixed by the clamp member. A recording medium driving device comprising: a clamp member and / or a rotor hub, each of which has an annular press-contact portion that press-contacts with each other, on an outer peripheral portion of the tightening means, of portions of the clamp member and the rotor hub that face each other. In the recording medium drive device, an annular portion on the outer peripheral side of the press contact portion is formed in a concave portion where the clamp member and the rotor hub are not in contact with each other. 2. A recording medium driving device in which a through hole provided in a rotor hub for holding and holding a recording medium for rotation is sealed by a seal member fixed to the rotor hub. A recording medium driving device, wherein a seal member is fixed to a rotor hub by heat curing of an attached thermosetting adhesive.