JP2000082252A - Fixed magnetic disk drive and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide a fixed magnetic disk drive capable of reliably sealing a sleeve and a housing of a dynamic pressure bearing. SOLUTION: A sleeve 2 is bonded to a housing 3 with an adhesive 18.
(1) Adhesive 18 for fixing sleeve 2 to housing 3
Is protruded from the bonding gap in the bonding step, and the protruding adhesive is cured by heat or ultraviolet rays. (2) The space other than the adhesive gap is filled and sealed with an adhesive 30 different from the adhesive 18 for fixing the sleeve to the housing. (3) A tapered space is provided on the housing side or the sleeve side so that the adhesive to be sealed can be irradiated with ultraviolet rays. (4) Use a conductive adhesive as an airtight adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal for a bearing in a spindle motor of a fixed magnetic disk (also referred to as a hard magnetic disk or hard disk) drive.

[0002]

2. Description of the Related Art In recent years, these devices used for OA devices have been increasingly reduced in size and performance, and accordingly, spindle motors have also been required to be reduced in size. The components of the spindle motor are also small. For assembling the spindle motor members, there have been many methods of using an adhesive as a method other than press-fitting and caulking in order to prevent deformation of the members. However, in the fixed magnetic disk drive, press-fitting is often used for fixing components because the inclination of the shaft as the temperature becomes higher is extremely restricted for the reliability of magnetic recording. For press-fitting, sufficient press-fitting allowance and press-fitting width are required to secure the fastening strength.

In recent years, in particular, ball bearings cannot achieve sufficient rotational accuracy, and hydrodynamic bearings have begun to be used instead of ball bearings, and spindle motors with higher capacity and higher precision are being developed. .

In the case of a hydrodynamic bearing of a 3.5-inch or 5-inch fixed magnetic disk drive and a shaft outer diameter of 5 mm, the radius clearance between the sleeve and the shaft of the hydrodynamic bearing is 4 μm to 10 μm, and the outer diameter of the sleeve is 10mm-1
When the length is 5 mm, even when the sleeve is pressed into the rotor hub or the housing, the deformation of the sleeve inner diameter is small, and the level is practically acceptable.

In recent years, the capacity per flutter has increased, and the number of disks used in a widespread fixed magnetic disk recording device has been reduced. Therefore, in a 3.5-inch fixed magnetic disk drive or a 2.5-inch fixed magnetic disk drive on which four or less magnetic disks are mounted, the height of the fixed magnetic disk drive is also reduced, and the press-fit width of the sleeve is reduced. Have been. In order to secure the press-fitting strength, a general solution is to increase the press-fitting allowance, but a method of using both press-fitting and bonding has been adopted. The reason for this is that in a small-sized magnetic disk drive using a hydrodynamic bearing device, the radial clearance between the sleeve and the shaft of the hydrodynamic bearing is 1.5 μm to 3 μm in order to secure shaft rigidity. The cylindricity is also 1 μm or less in the bearing having the above clearance. When the sleeve is pressed into the housing with such a bearing, the clearance changes and the cylindricity becomes 2 μm or more, so that the function as a dynamic pressure bearing may not be achieved.

Among such small-sized fixed magnetic disk drives, there has been developed an ultra-small fixed magnetic disk drive which is mounted on a portable terminal device having slightly different specifications from recent notebook personal computers and mobile computers. It is getting. Since it is used for mobile terminals, there are demands for excellent impact resistance and low noise. In response to such demands, magnetic disks have also become smaller and thinner than 2.5 inches, and thinner spindle motors have been developed for such devices.
The length of the bearing is also becoming very short.
In the method of fastening the bearing member to the housing, the deformation of the bearing part is large in press-fitting and bonding, and the reliability is unstable in the configuration with the dynamic pressure bearing, and it is attempted to use the fastening that eliminates the press-fit which is the main cause of deformation Attempts have been made. Simply, it is fastening by adhesion. For hydrodynamic bearings of thin devices,
It is only necessary to use a method that meets the conditions such as the bonding width and the fastening strength of the bearing part of the spindle motor, which will inevitably shorten the bonding width, but in fact, fixed magnetic disk drive used in portable terminal equipment etc. Requires high impact resistance, and the joint strength of the bearing members also requires a value in accordance with the usage form.

Further, a fixed magnetic disk drive (hereinafter referred to as H
The hole with the filter secures air permeability with the outside due to abnormal changes such as internal pressure of the inside (referred to as DD). Since the inside of the HDD is extremely unlikely to be contaminated, a filter is provided in a ventilation part with the outside. As HDDs become smaller and thinner, adhesion is often used to fasten bearings,
Adhesion width is shortened, and depending on the degree of curing of the adhesive and the type of adhesive in the heat cycle evaluation test, etc., there is a communication hole with the outside at the bonding part of the bearing member, and internal contamination conditions deteriorate, Since the bearing portion is located at the center of rotation, a negative pressure is apt to occur, and air is mixed in from the outside through the communication hole provided in the bonding portion. Outside, the contamination condition is bad,
By changing the contamination conditions and pressure conditions inside the HDD,
The gap between the magnetic head and the magnetic disk is disturbed.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an HDD which can reliably seal the sleeve and housing of a dynamic pressure bearing of the HDD.

Ultra-small HDDs of 2.5 inches or less mounted on small notebook personal computers, mobile computers, and portable terminal devices are used for information recording devices of devices that place importance on portability. Demand for low power consumption and low noise. Among them, ball bearings are at a level that cannot be guaranteed against the impact resistance requirements. For that purpose, a hydrodynamic bearing other than a ball bearing is used. The hydrodynamic bearing is configured so that the rotating part and the fixed part are in non-contact with each other via a lubricating fluid, and rotates the rotating part with high precision. The spindle motor of the ultra-small hydrodynamic bearing has a bearing radial gap of about 2 μm. Yes, if the bearing member is fastened by press fitting, the inner diameter of the bearing sleeve will be reduced, and the cylindricity will deteriorate, so that the predetermined dynamic pressure characteristics and the predetermined gap cannot be secured,
Reliability cannot be improved. For this reason, in the case of a hydrodynamic bearing, an adhesive is often used to fix the sleeve and the housing in the shaft-rotating type HDD and to fix the sleeve and the rotor hub in the shaft-fixing type HDD. In the case of a hydrodynamic bearing of a thin device or the like, the bonding width is inevitably shortened. The fastening strength of the bearing portion of the spindle motor can be secured only in accordance with the bonding width. Furthermore, the above-mentioned bonding width is further reduced in order to escape deformation of the swaged part of the thrust bearing part,
For example, there is a length of about 3 mm in the axial direction, but in a configuration in which about 1.5 mm to 2 mm cannot be used with a thrust bearing in consideration of a relief portion due to caulking of a thrust plate (0.5 mm) or the like, the bonding width is It is about 1 mm, and it is difficult to secure an adhesive strength that can withstand a shock resistance of 1000 G. Ensuring the bonding strength is an important issue for ultra-small HDDs.

In particular, in the case of a shaft-rotation type HDD in which a bearing portion is exposed to the outside, it is necessary to ensure sufficient airtightness in addition to the adhesive strength between the housing and the sleeve.

Although the sleeve of the dynamic pressure bearing is fastened to the housing by bonding, the inside of the HDD is kept airtight with respect to the outside by filling the bonding gap with the bonding agent. However, as the spindle motor becomes thinner, the length of its bearing portion also becomes shorter, and the adhesive gap in which the sleeve of the dynamic pressure bearing is fastened to the housing by bonding is not filled with the adhesive. The inside may not be airtight with the outside. Furthermore, H
When the DD becomes smaller and thinner, the adhesive is often used for fastening the bearing, and the bonding width is shortened. When the temperature difference of the usage environment changes greatly, the heat cycle evaluation test, and the curing of the adhesive in a high temperature environment, etc. Depending on the degree of the adhesive and the type of adhesive, the adhesive further cures, and the volatile components contained in the adhesive jump out and change the weight of the adhesive, resulting in a decrease in the amount of the adhesive. In addition, the bonding portion of the bearing member has a communication hole with the outside, and the communication hole connects the inside and the outside without a filter and opens at an unexpected place. Therefore, the reliability of the HDD is deteriorated, for example, due to the deterioration of the contamination condition inside the HDD.

Also, if an unexpected communication hole is formed in the bonding portion,
Since the bearing part is the center of rotation, it tends to be negative pressure,
Air is mixed in from the outside through the communication hole formed in the bonding portion. Externally, contamination conditions are poor, and it becomes impossible to manage environmental conditions inside the HDD, which disturbs a gap between the magnetic head and the magnetic disk, and there is a great possibility that an R / W processing error or the like will occur.

Further, in the fluid bearing, since the shaft and the sleeve are in a non-contact state, the charged electric charge is accumulated on the magnetic disk due to friction with air with the rotation, and is discharged to the magnetic head side. As a result, the magnetic head is electrostatically damaged. In order to eliminate the electrostatic breakdown of the magnetic head, it is necessary to use a conductive material so that electric charges flow toward the housing.

[0014]

When the sleeve is fixed to the housing with an adhesive, (1) the adhesive for fixing the sleeve to the housing is protruded from the bonding gap in the bonding step, and the protruding adhesive is heated. Alternatively, it is cured with ultraviolet light. (2) The space other than the adhesive gap is filled and sealed with an adhesive different from the adhesive fixing the sleeve to the housing. (3) A tapered space is provided on the housing side or the sleeve side so that the adhesive to be sealed can be irradiated with ultraviolet rays.

The space starts to taper from the inner side of the bearing surface of the thrust plate of the sleeve. Alternatively, the taper is started from the inner side, and the taper is formed of two types of taper. When both are caulked and fixed to the thrust plate, obstruction of sleeve insertion due to the bulging of the sleeve outer diameter due to caulking is eliminated. (4) Use a conductive adhesive as an airtight adhesive. It is what it was. (5) A stator assembly in which the stator core around which the coil is wound is fixed to the housing, and a shaft is fastened and fixed to the rotor hub, and a hub assembly in which the magnetized drive magnet is bonded and fixed is formed. Then, a thrust plate is caulked and fixed to the sleeve to form a bearing assembly.Next, a predetermined amount of lubricating fluid is dripped at a predetermined position on the inner peripheral portion of the sleeve of the bearing assembly, and the shaft of the hub assembly is inserted into the sleeve. Then, the retaining plate is fixed to the rotor hub, an adhesive is applied to the inner peripheral portion of the inner cylindrical portion of the housing of the stator assembly, and a sleeve is inserted. The distance between the housing and the sleeve is fixed by adhering and fixing the distance from the disk receiving surface to the specified value. Manufacturing method for performing sexual with adhesive. (6) A stator assembly in which the stator core around which the coils are wound is fixed to the housing, and a shaft is fastened and fixed to the rotor hub, and a hub assembly in which the magnetized drive magnet is bonded and fixed is formed. Then, a thrust plate is caulked and fixed to the sleeve to form a bearing assembly, and then a lubricating fluid is injected into a predetermined position on the inner peripheral portion of the sleeve of the bearing assembly, and the shaft of the hub assembly is inserted into the sleeve. Next, the retaining plate is fixed to the rotor hub, an adhesive (adhesive a) is applied to an inner peripheral portion of the inner cylindrical portion of the housing of the stator assembly, a sleeve is inserted, and a reference surface of the housing is inserted. The distance between the magnetic disk receiving surface of the rotor hub and the fixed magnetic disk receiving surface is fixed to a specified value, and the gap between the sleeve on the thrust plate side and the housing is made of an ultraviolet-curing adhesive (adhesive And b) a is irradiated with ultraviolet rays to be cured, the adhesive b airtightness two adhesive (the adhesive a in the housing and the sleeve manufacturing method carried out in a separate adhesive).

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a housing, a sleeve fixed to the housing, a rotor hub rotatable relative to the housing, and a fastening to the rotor hub. A shaft, a drive magnet directly or indirectly mounted on the rotor hub, and a stator core disposed opposite the drive magnet, wherein the shaft is connected to the sleeve via a lubricating fluid. In the rotating drive, a fixed magnetic disk is mounted on the rotor hub, a thrust plate is fixed to one end of the sleeve, the sleeve and the housing are fastened with an adhesive, and the adhesive protruding toward the thrust plate is irradiated with ultraviolet rays. The fixed magnetic disk drive is characterized in that it is cured and the airtightness between the housing and the sleeve is performed with an adhesive. In the bonding step, the adhesive for fixing the sleeve to the housing is protruded from the bonding gap, and the protruding adhesive is cured by heat or ultraviolet rays. By sealing with the excess adhesive that has protruded even when the air is ventilated, the airtightness of the device can be ensured.

According to a second aspect of the present invention, a housing,
A sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, a drive magnet mounted directly or indirectly on the rotor hub, A drive unit that rotates the shaft via a lubricating fluid with respect to the sleeve, wherein the shaft is a stator assembly in which a stator core around which a coil is wound is fixed to a housing. Make, and also fasten and fix the shaft to the rotor hub,
Make a hub assembly with the magnetized drive magnet bonded and fixed, then crimp a thrust plate to the sleeve to form a bearing assembly, and then place the bearing assembly at a predetermined position on the inner circumference of the sleeve of the bearing assembly. A prescribed amount of lubricating fluid is instilled, the shaft of the hub assembly is inserted into the sleeve, then the retaining plate is fixed to the rotor hub, and an adhesive is applied to the inner peripheral portion of the inner cylindrical portion of the housing of the stator assembly. Apply, insert the sleeve, glue and fix so that the distance between the reference surface of the housing and the fixed magnetic disk receiving surface of the rotor hub is the specified value, and irradiate the adhesive protruding to the thrust plate side with ultraviolet rays and cure. And a method of manufacturing a fixed magnetic disk drive in which airtightness between the housing and the sleeve is performed by using an adhesive. Thereby protrude from the bond gap in step,
The extruded adhesive is cured with heat or ultraviolet rays, and even if the adhesive gap between the sleeve and the housing becomes uneven and the air is ventilated to the outside, it is sealed with the excess adhesive that has protruded. Because of the effect that the property can be secured, near the completion of the motor assembly, the adhesive protruding to the thrust plate side is cured by irradiating it with ultraviolet light,
This is a manufacturing method having an effect of performing airtightness between the housing and the sleeve with an adhesive, improving the fastening strength including a protruding hardened adhesive, and securing the fastening strength that can withstand impact resistance.

According to a third aspect of the present invention, a housing,
A sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, a drive magnet mounted directly or indirectly on the rotor hub, A stator core disposed opposite to the magnet, wherein the shaft rotates with a lubricating fluid with respect to the sleeve, in which a fixed magnetic disk is mounted on a rotor hub, and a thrust plate is provided at one end of the sleeve. After fixing, the sleeve and the housing are fastened with an adhesive (adhesive a), and the gap between the sleeve and the housing on the thrust plate side is irradiated with ultraviolet rays to an ultraviolet curable adhesive (adhesive b). To cure the airtightness between the housing and the sleeve by using two types of adhesives (adhesive a and adhesive b).
Is a fixed magnetic disk drive characterized in that it is performed with another adhesive, and the space other than the adhesive gap is filled and sealed with an adhesive different from the adhesive that fixes the sleeve to the housing. By stopping, the airtightness of the device can be ensured, and furthermore, the adhesive b has the function of also acting as a strength member. In the case of a conventional HDD having a short bonding width, such as a thin device, which has improved fastening strength due to bonding, it is possible to provide an HDD having high impact resistance, and there is no occurrence of a communication hole or the like in a bonding portion of a bearing portion. There is an operational effect that reliability is further improved by increasing airtightness. Portable HDD
Suitable fastening method and sealing method can be provided.

According to a fourth aspect of the present invention, a housing,
A sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, a drive magnet mounted directly or indirectly on the rotor hub, A drive unit that rotates the shaft via a lubricating fluid with respect to the sleeve, wherein the shaft is a stator assembly in which a stator core around which a coil is wound is fixed to a housing. Make, and also fasten and fix the shaft to the rotor hub,
Make a hub assembly with the magnetized drive magnet bonded and fixed, then crimp a thrust plate to the sleeve to form a bearing assembly, and then place the bearing assembly at a predetermined position on the inner circumference of the sleeve of the bearing assembly. Lubricate the lubricating fluid, insert the shaft of the hub assembly into the sleeve, then fix the retaining plate to the rotor hub, and apply an adhesive (adhesive) to the inner peripheral portion of the inner cylindrical portion of the housing of the stator assembly. a), and a sleeve is inserted. The sleeve is bonded and fixed so that the distance between the reference surface of the housing and the fixed magnetic disk receiving surface of the rotor hub becomes a specified value. Is cured by irradiating an ultraviolet-curable adhesive (hereinafter referred to as an adhesive b) with ultraviolet light, and the airtightness between the housing and the sleeve is reduced by two types of adhesives (an adhesive a and an adhesive b).
Is a method of manufacturing a fixed magnetic disk drive, characterized in that it is performed with another adhesive). The adhesive other than the adhesive for fixing the sleeve to the housing is used in a space other than the adhesive gap. By filling and sealing, the airtightness of the device can be ensured, and furthermore, the adhesive b has the function of also acting as a strength member. In the case of an HDD with a short bonding width, such as a thin device, where the bonding strength is improved due to bonding,
In addition to providing an HDD having high impact resistance, there is an effect that the reliability is further improved by increasing the airtightness. A suitable fastening method for a portable HDD can be provided. While increasing the airtightness between the housing and the sleeve,
The two types of adhesives are used for adhesive fixing and sealing, and the two types of adhesives are used to improve the fastening strength, to secure the fastening strength that can withstand impact resistance, and to seal the bearing. Is the way.

According to a fifth aspect of the present invention, there is provided the fixed magnetic disk drive according to the third aspect, wherein the viscosity of the adhesive a is larger than the viscosity of the adhesive b.
The adhesive gap between the sleeve and the housing can be reduced, and the sleeve is easily installed vertically without inclination with respect to the housing. Can be cured. Further, the adhesive b has the function of also acting as a strength member.

According to a sixth aspect of the present invention, there is provided the fixed magnetic disk drive according to the third aspect, wherein the adhesive mainly having airtightness is a conductive adhesive and is of an ultraviolet curing type. The conductive adhesive makes the fixed magnetic disk and the chassis of the apparatus main body conduct at a low resistance, and the electric charge generated in the air is hardly charged on the surface of the magnetic disk.
This has the effect of eliminating electrostatic breakdown of the magnetic head.

According to a seventh aspect of the present invention, in a fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and the sleeve is fixed to a housing by bonding, the thrust plate is The start of the small diameter portion which is fixed by caulking to the bearing surface of the sleeve and which is smaller in diameter than the bonding outer diameter of the sleeve at the caulking side sleeve is located on the motor inner side of the seat surface, and comprises the small diameter portion and the housing. 6. A fixed magnetic disk drive according to claim 1, wherein an airtightness between the housing and the sleeve is ensured by interposing an adhesive in the gap provided. Since the tapered small-diameter portion is provided on the side, the opening is wide toward the outside, so that ultraviolet rays can be stably irradiated. Therefore, the curing of the adhesive proceeds in a short time, and the temperature rise of the parts due to the irradiation of ultraviolet rays can be suppressed,
The change in the gap due to the difference in the thermal expansion coefficient due to the temperature rise of the fluid bearing portion can be kept small, and the outflow of the dynamic pressure fluid due to expansion or the like can be suppressed.

In addition, since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembling process is stabilized.

Further, since the adhesive is hardened in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved.

According to an eighth aspect of the present invention, in a fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and the sleeve is fixed to a housing by bonding, the thrust plate is The start of the small diameter portion which is fixed by caulking to the bearing surface of the sleeve and which is smaller in diameter than the bonding outer diameter of the sleeve at the caulking side sleeve is located on the motor inner side of the seat surface, and comprises the small diameter portion and the housing. 5. The method for manufacturing a fixed magnetic disk drive according to claim 2, wherein airtightness between the housing and the sleeve is ensured by interposing an adhesive in the formed gap. Since the tapered small-diameter portion is provided on the sleeve side, the opening is wide toward the outside, so that ultraviolet rays can be stably emitted. Therefore, the curing of the adhesive proceeds in a short time, the temperature rise of the parts due to the irradiation of ultraviolet rays can be suppressed, and the change in the gap due to the difference in the thermal expansion coefficient due to the temperature rise of the fluid bearing portion is suppressed to a small degree, and the expansion is caused by expansion. Outflow of the hydrodynamic fluid can be suppressed.

In addition, since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, it is possible to reduce the bonding gap and stabilize the assembly process.

Further, since the adhesive hardens in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved.

According to a ninth aspect of the present invention, in a fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing, and the sleeve is fixed to a housing by bonding, the thrust plate is The beginning of the small diameter portion having a diameter smaller than the outer diameter of the sleeve on the caulking side sleeve is fixed to the bearing surface of the sleeve by caulking, and the beginning of the small diameter portion is located closer to the inside of the motor than the seating surface. The caulking portion is formed by another tapered portion facing the side, and an adhesive is interposed in a gap formed by the two tapered portions and the housing to ensure airtightness between the housing and the sleeve. The fixed magnetic disk drive according to any one of claims 1, 3 and 5, wherein the tapered small diameter portion is provided on the sleeve side so that the opening is wide to the outside, so that ultraviolet rays are emitted. It can be irradiated to a constant. Also,
Since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembly process is stabilized. In addition to improving the adhesive strength, even if the temperature changes,
Since the area of the adhesive in contact with air is small, the change in weight after curing is small, and the occurrence of communication holes and the like in the bearing portion can be suppressed.

Further, since the adhesive is hardened in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved.

According to a tenth aspect of the present invention, in a fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and this sleeve is fixed to a housing by bonding, the thrust plate is a sleeve. The beginning of the small diameter portion having a diameter smaller than the outer diameter of the adhesive on the sleeve on the caulking side is located closer to the inside of the motor than the seat surface, and the smaller diameter portion is tapered. In addition, the caulking portion is formed by another tapered portion toward the side, and an adhesive is interposed in a gap formed by the two tapered portions and the housing to ensure airtightness between the housing and the sleeve. The method of manufacturing a fixed magnetic disk drive according to claim 2 or 4, wherein the tapered small diameter portion is provided on the sleeve side so that the opening is wide to the outside, so that ultraviolet rays are cheap. It can be irradiated to. As a result, there is no unevenness in curing, no inclination of the bearing due to variation in curing, etc., and a device with good assembly accuracy can be provided. Further, the adhesive strength by the adhesive is improved. In addition, since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembling process is stabilized.

Further, since the adhesive hardens in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, so that the fastening strength of the bearing device is improved and the airtightness of the bearing portion is improved. This has the effect of providing a highly reliable device without the formation of ventilation holes.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a cross-sectional view of a fixed magnetic disk drive using a hydrodynamic bearing device according to an embodiment of the present invention, and FIG. 2 is an enlarged explanatory view showing a state where a sleeve is bonded and fixed to a housing. is there.

In FIG. 1, 1 is a rotor hub, 2 is a sleeve, 3 is a housing, 4 is a thrust plate, 5 is a stator core, and 6 is a drive magnet. Fixed magnetic disk 7
Is mounted on the rotor hub 1 and the clamper 8 is tightened with the screw 9 to fix the fixed magnetic disk 7. The fixed magnetic disk drive that rotates the fixed magnetic disk 7 has a hermetically sealed structure, and extremely dislikes outgas and dust. Furthermore, to prevent the internal pressure from rising abnormally,
A ventilation hole (also referred to as a ventilation hole) is provided. A filter is installed in the hole so that clean air can be ventilated inside. The inside of the device is provided with a ventilation mechanism to the outside only from the ventilation hole.

A spindle motor section is formed substantially at the center of the fixed magnetic disk drive. The housing 3 of the spindle motor has a configuration of a flange portion 10, an inner cylindrical portion 11, and an outer cylindrical portion 12, and the flange portion 1
0 is attached to the chassis 13 of the HDD, and the outer cylindrical portion 12 and the outer peripheral portion of the rotor hub 1 form a labyrinth with a small gap of about 0.2 mm. The sleeve 2 is attached to the inside of the inner cylindrical portion 11 by bonding. A stator core 5 around which a coil 14 is wound is fixedly adhered to the outer peripheral surface of the inner cylindrical portion 11 of the housing 3. The rotor hub 1 has a cup shape including a fixed magnetic disk receiving surface 16 and a cylindrical portion 17 for regulating the inner diameter of the fixed magnetic disk. A cylindrical drive magnet 6 having N and S poles alternately magnetized in the circumferential direction is bonded and fixed to the inner periphery of the cylindrical portion of the rotor hub 1. The rotor hub 1 is provided with a retaining plate 19 for preventing the rotor hub 1 from falling off. A shaft 20 is press-fitted into the center of the rotor hub 1.

The shaft 20 is rotatably inserted into the inner diameter hole of the sleeve 2 having the first and second cylindrical portions 21 and 22 having herringbone grooves on the inner peripheral surface thereof.
This constitutes a radial hydrodynamic bearing device in which a lubricating fluid is interposed in the gap between the sleeve 0 and the sleeve 2.

One end surface of the shaft 20 has a spherical shape, and a pivot bearing is formed by the spherical surface and the thrust plate 4, and a lubricating fluid is interposed in a gap between the pivot bearings to constitute a thrust pivot bearing. are doing.

Between the first cylindrical portion 21 and the second cylindrical portion 22, a cylindrical fluid holding portion 23 having a large diameter is formed.
When the fluid holding portion 23 and the first cylindrical portion 21 are inclined surfaces,
The fluid holding portion 23 and the second cylindrical portion 22 are also inclined surfaces. Further, a space 24 is provided on the thrust pivot bearing side of the sleeve 2. The lubricating fluid is shaft 20
The fluid holding portion 23 of the sleeve 2 does not contribute to the generation of dynamic pressure, and is a gap for holding a lubricating fluid. The space 24 is a space for holding a lubricating fluid for the thrust bearing and the radial bearing.

Fixed magnetic disk receiving surface 1 of rotor hub 1
A fixed magnetic disk 7 is mounted on 6. The spindle motor of the fixed magnetic disk drive shown in the figure is a radial type brushless motor, and a current is applied to the coil 14 to generate a magnetic field at the salient poles of the stator core 5.
A torque is generated between the field driving magnet 6 facing the stator core 5 and the rotor hub 1 is rotated.
Therefore, the fixed magnetic disk 7 clamped to the rotor hub 1 also rotates with the rotation of the rotor hub 1.

When the shaft 20 rotates, a dynamic pressure is generated by pumping a lubricating fluid by the action of a herringbone groove provided in the cylindrical portions 21 and 22 of the sleeve 2. Therefore, the shaft 20 floats with respect to the sleeve 2 and rotates without contact.

The lubricating fluid is oil to which conductivity has been added, and the shaft 20 and the housing 3 are in a conductive state even during rotation, so that the fixed magnetic disk and the apparatus chassis are in a conductive state. Therefore, static electricity is not charged to the fixed magnetic disk due to friction between the fixed magnetic disk and air during rotation of the fixed magnetic disk, so that a potential difference does not occur between the fixed magnetic disk and the magnetic head.

A flexible printed circuit board 25 is attached to the housing 3, and the terminals of the coil 14 are soldered to the flexible printed circuit board 25 to conduct to the drive circuit.

Next, a method of assembling the fixed magnetic disk drive of this embodiment will be described.

(1) The flexible printed board 25 is attached to the housing 3 with an adhesive. Next, an adhesive is applied to the inner cylindrical portion 11 of the housing 3, a coil 35 is wound around the stator core 5 insulated by the electrodeposition coating film, and the stator core 5 is inserted into the inner cylindrical portion 11 and fixed by adhesion. The processed coil terminals are connected to the flexible printed circuit board 25.
To make a stator assembly.

(2) Next, the shaft 2 is attached to the rotor hub 1.
0 is press-fitted and fixed, and an adhesive is further applied to the rotor hub 1, and the magnetized drive magnet 6 is inserted and bonded and fixed to form a hub assembly.

(3) Next, the thrust plate 4 is
Is caulked and fixed, and a bearing assembly in which the caulked portion is sealed with the adhesive 15 is produced.

(4) Next, a predetermined amount of lubricating fluid is dripped at a predetermined position on the inner peripheral portion of the sleeve 2 of the bearing assembly, and the shaft 20 of the hub assembly is inserted into the sleeve 2.

(5) Next, the retaining plate 19 is fixed to the rotor hub 2 with the rotor hub 1 facing down.
9, a hydrodynamic bearing device that does not come off is obtained.

(6) A predetermined amount of the anaerobic adhesive 18 is applied to the inner peripheral portion of the inner cylindrical portion 11 of the housing 3 of the stator assembly, and the sleeve 2 of the hydrodynamic bearing device is inserted. Adhesive fixing is performed so that the distance between the reference surface of the housing 3 and the fixed magnetic disk receiving surface 16 of the rotor hub 1 becomes a specified value.

As described above, the fixed magnetic disk drive using the hydrodynamic bearing device is assembled.

FIG. 2 is a schematic explanatory view in which the sleeve 2 is bonded and fixed to the housing 3. Internal cylindrical part 1 of housing 3
The adhesive 18 is applied to a predetermined portion of the inner surface of the adhesive surface 1 with a dispenser, and the sleeve 2 of the hydrodynamic bearing device is inserted from the rotor hub side (upper side in FIG. 2). An excess amount of the adhesive 18 that is larger than the amount to be filled in the bonding gap is squeezed into the sleeve 2 at the time of insertion and protrudes outside. Since the excess adhesive 18a that has protruded is anaerobic, it does not cure in the space 26 where the bonding gap is large. The adhesive 18 is, for example, 648 UV manufactured by Nippon Loctite, an ultraviolet-curing anaerobic adhesive, and also has heat curing. By setting the surplus adhesive 18a in an environment of a high temperature of 70 ° C. for 2 hours and curing it, even if an adhesion gap occurs in an adhesion gap between the sleeve 2 and the housing 3 and a ventilation state with the outside occurs, excessive adhesion occurs. Agent 18a
By sealing in this way, the airtightness of the device can be ensured.

Due to the problem of work efficiency, the excess adhesive 18a
May be cured by irradiating ultraviolet rays.

The space 26 is a hollow circular space composed of a tapered small diameter portion 27 and a tapered portion 28 of the housing 3 on the outer peripheral portion of the sleeve 2, and has a wide mouth to the outside, so that ultraviolet rays are stably provided. Can be irradiated.

Further, since the excess adhesive 18a is hardened in the space 26 between the sleeve 2 and the housing 3, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved.

The radial clearance between the sleeve and the shaft of the hydrodynamic bearing is, for example, 2 μm to secure the shaft rigidity, and the inner diameter of the sleeve is 0.3 μm.

In such a bearing, when the sleeve is press-fitted into the housing, the center portion of the inner diameter of the sleeve is protruded inward, and a minimum clearance is generated. The degree becomes 2.5 μm. Since it is not considered that such a bearing can secure sufficient reliability, press fitting is not used for fixing the sleeve and the housing.

Therefore, in the present invention, the sleeve and the housing are fixed by bonding. According to the adhesive fixation, the inner diameter and cylindricity of the sleeve maintain the accuracy of the sleeve alone.
Therefore, the performance of the bearing can be grasped as a single product, and a highly reliable fixed magnetic disk drive having a dynamic bearing specification can be obtained.

The thrust plate 4 is fixed to the seat 29 of the sleeve 2 by caulking. Depending on the shape of the swaging portion of the sleeve 2, the swaging force may be insufficient, and the adhesion between the seat 10 and the thrust plate 3 may be deteriorated. The set position of the biting thrust plate may change, or the inner diameter of the sleeve 2 may be deformed.

When the thrust plate is fixed by caulking, if the caulking portion has a cylindrical outer diameter, the outer diameter is deformed by the caulking effect on the outer periphery of the sleeve. A tapered small diameter portion 28 on the outer periphery of the sleeve near the caulking portion is provided so that the caulking does not affect the outer diameter of the sleeve.

Since the opening is tapered and wide-mouthed so as to be suitable for irradiation with ultraviolet rays, the ultraviolet rays can be stably irradiated. As a result, there is no unevenness in curing, no inclination of the bearing due to variation in curing, etc., and a device with good assembly accuracy can be provided. Further, the adhesive strength by the adhesive is improved. In addition, since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembling process is stabilized.

The positional relationship between the seat 29 of the sleeve 2 and the starting point of the tapered small-diameter portion 28 of the sleeve 2 is as follows. The starting point of the tapered small diameter portion 28 of the sleeve 2 with respect to the seat 29 of the sleeve 2 is on the rotor hub side. FIG.
, The upper direction of the drawing is set to the forward direction,
Is the origin, y ≧ 0 when the start point position y of the tapered small-diameter portion 28 of the sleeve 2 is set as y.

In the above description, the housing is the housing of the driving device and is separated from the chassis of the device main body. However, the housing can be similarly implemented even if it is integrated with the main body chassis.

In an HDD using a thin hydrodynamic bearing, the bonding width is inevitably reduced. As shown in FIG. 1 and the like, the adhesive width is further reduced in order to avoid deformation of the crimped portion of the thrust bearing portion. For example, although there is a length of about 3 mm in the axial direction, caulking of the thrust plate (0.5 mm) is performed. For this reason, there may be a case where about 1.5 mm to 2 mm cannot be used due to a thrust bearing in consideration of a relief portion or the like. In this case, the bonding width is about 1 mm, but one kind of adhesive is protruded, and the protruding adhesive is irradiated from the bottom side of the housing with ultraviolet light, and the adhesive including the ultraviolet curable adhesive is included. By fastening and fixing the bearing part, the bonding strength enough to withstand high impact resistance could be secured.

As the HDD becomes smaller and thinner, the bonding width of the bearing becomes shorter, and the degree of curing of the adhesive and the degree of curing of the adhesive in a case where the temperature difference in the use environment changes greatly, a heat cycle evaluation test, a high temperature environment, etc. Depending on the type of the adhesive, the adhesive further hardens, and the volatile components contained in the adhesive jump out and change the weight of the adhesive, resulting in a decrease in the amount of the adhesive and the bonding of the bearing member. The formation of a communication hole with the outside in the portion can be prevented by irradiating the ultraviolet rays and curing the adhesive so that the adhesive that touches the air can be cured quickly. Therefore, there is no influence due to uneven application of the adhesive, and sufficient airtightness can be maintained.

Since sufficient airtightness is possible, there is no possibility of deterioration in reliability such as deterioration of contamination conditions inside the HDD. The gap between the magnetic head and the magnetic disk is stabilized, and there is no possibility of an R / W processing error.

(Embodiment 2) Embodiment 2 is different from Embodiment 1 only in the configuration of the bonding portion between the sleeve and the housing in the fixed magnetic disk drive of Embodiment 1, and FIG. I do. FIG. 3 is an enlarged explanatory view showing a state where the sleeve is bonded and fixed to the housing.
This is an example using different types of bonding. Since the fixed magnetic disk drive according to the second embodiment is similar to that of the first embodiment, the same reference numerals are used for parts and the like.

A method of assembling the fixed magnetic disk drive in the case of FIG. 3 will be described. See FIG.

(1) The flexible printed circuit board 25 is attached to the housing 3 with an adhesive. Next, an adhesive is applied to the inner cylindrical portion 11 of the housing 3, a coil 35 is wound around the stator core 5 insulated by the electrodeposition coating film, and the stator core 5 is inserted into the inner cylindrical portion 11 and fixed by adhesion. The processed coil terminals are connected to the flexible printed circuit board 25.
To make a stator assembly.

(2) Next, the shaft 2 is attached to the rotor hub 1.
0 is press-fitted and fixed, and an adhesive is further applied to the rotor hub 1, and the magnetized drive magnet 6 is inserted and bonded and fixed to form a hub assembly.

(3) Next, the thrust plate 4 is
Is caulked and fixed, and a bearing assembly in which the caulked portion is sealed with the adhesive 15 is produced.

(4) Next, a predetermined amount of lubricating fluid is dripped at a predetermined position on the inner peripheral portion of the sleeve 2 of the bearing assembly, and the shaft 20 of the hub assembly is inserted into the sleeve 2.

(5) Next, the retaining plate 19 is fixed to the rotor hub 2 with the rotor hub 1 facing down.
9, a hydrodynamic bearing device that does not come off is obtained.

(6) A predetermined amount of the anaerobic adhesive 18 is applied to the inner peripheral portion of the inner cylindrical portion 11 of the housing 3 of the stator assembly, and the sleeve 2 of the hydrodynamic bearing device is inserted. Adhesive fixing is performed so that the distance between the reference surface of the housing 3 and the fixed magnetic disk receiving surface 16 of the rotor hub 1 becomes a specified value.

The above is the assembly procedure of the first embodiment, but the second embodiment has the following additional steps. (7) A space formed by the sleeve 2 and the housing 3 is filled with an adhesive 30 different from the adhesive fixing of the sleeve 2,
It is cured by irradiating ultraviolet rays.

The fixed magnetic disk drive using the hydrodynamic bearing device is assembled as described above.

The steps of applying the adhesive 18 and the adhesive 30 will be described again in detail. Adhesive 18 is applied by a dispenser to a predetermined location on the inner peripheral surface of the inner cylindrical portion 11 of the housing 3 with a dispenser, and the sleeve 2 of the hydrodynamic bearing device is inserted from the rotor hub side (upper side in FIG. 3). The amount of the adhesive 18 is about the amount to be filled in the adhesive gap. Even if the adhesive 18 is squeezed by the sleeve 2 at the time of insertion and protrudes out of the adhesive gap due to variation in the process operation, the amount is small. Adhesive 18
For example, 601M manufactured by Nippon Loctite Co., Ltd. is used. The adhesive 601M is an anaerobic adhesive, has a small viscosity of about 150 cps at a temperature of 25 ° C., and cures quickly at high temperatures.

The distance between the reference surface of the housing 3 and the fixed magnetic disk receiving surface 16 of the rotor hub 1 is set to a specified value.
8 is cured by adhesion. In this state, the fixed magnetic disk drive is completed.
If there is uneven bonding in the adhesive gap and air is ventilated to the outside, external air enters the inside of the apparatus without a filter. The curable adhesive 30 is applied with a dispenser, and the adhesive 30 is irradiated with ultraviolet rays to be cured. The adhesive 30 is made of, for example, 4X623P manufactured by Chemitech Co., Ltd.
Use such as. The adhesive 623P also has a viscosity at a temperature of 25 ° C. of 500 cps. The adhesive 30 is an ultraviolet-curable adhesive, and has thermosetting and anaerobic properties. Therefore, the adhesive 30 is anaerobic even when it enters a gap such as uneven bonding of an adhesive gap, and is cured.

The adhesive 18 and the adhesive 30 have different viscosities at 25 ° C., and the adhesive 18 has a lower viscosity. Housing 3
In order to set the shaft 20 vertically, the adhesive gap between the sleeve 2 and the housing 3 needs to be small, and the adhesive 18 having a small viscosity is used to reduce the adhesive unevenness of the adhesive. . Further, if the viscosity of the adhesive 30 is small, it is conceivable that the adhesive 30 may enter a gap such as uneven bonding and come out of the motor.
Make the viscosity greater than 8. Many of the adhesives 30 having a high viscosity are suitable for sealing a space, and there are many options. When the adhesive 30 having a high hardness after curing is selected, the adhesive 30 also functions as a strength member.

The space 26 is a hollow circular space formed by the tapered small-diameter portions 31 and 32 and the housing 3 on the outer peripheral portion of the sleeve 2 and has a wide opening to the outside, so that ultraviolet rays are stably irradiated. be able to. Since the three corners of the housing are provided with the inclined portion 28 having a tapered shape, it is possible to stably irradiate the ultraviolet rays and to prevent the adhesive 30 from protruding at the time of application.

Since the mouth is tapered and wide-mouthed so as to be suitable for irradiation with ultraviolet rays, ultraviolet rays can be stably emitted. As a result, there is no unevenness in curing, no inclination of the bearing due to variation in curing, etc., and a device with good assembly accuracy can be provided. Furthermore, the adhesive strength is improved by curing the two types of adhesives. In addition, since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembling process is stabilized.

Since the adhesive 30 is hardened in the space 26 between the sleeve 2 and the housing 3, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved.

The thrust plate 4 is fixed to the seat 29 of the sleeve 2 by caulking. When the thrust plate is fixed by caulking, the sleeve 2 cannot be inserted into the inner cylindrical portion 11 of the housing because the outer diameter is deformed due to the caulking on the outer periphery of the sleeve if the caulking portion has a cylindrical outer diameter. In order to eliminate the problem, the tapered small-diameter portions 31 and 32 on the outer periphery of the sleeve near the caulking portion are provided so that the caulking does not affect the outer diameter of the sleeve. In order to improve the impact resistance, the thrust plate needs to be a thrust plate with a smaller outer diameter as much as possible. Since the crimping portion is designed with the thrust plate, the outer diameter of the sleeve becomes larger, and the thrust plate in the first embodiment becomes smaller. Since the taper angle of the portion 27 becomes large and the outer diameter becomes close to that of a cylindrical sleeve, the tapered small diameter portion 32 of the caulking and the tapered small diameter portion 31 from the outer periphery of the sleeve to the small diameter portion 32 are formed. Eliminates deformation of the outer diameter due to the influence of caulking.

The positional relationship between the seat 29 of the sleeve 2 and the starting point of the tapered small diameter portion 31 of the sleeve 2 is as follows. The starting point of the tapered small-diameter portion 31 of the sleeve 2 with respect to the seat 29 of the sleeve 2 is on the rotor hub side.

Even if the intersection of the tapered small diameter portion 31 and the tapered small diameter portion 32 of the sleeve 2 is located outside the seat 29 of the sleeve 2, the influence of the caulking will not affect the sleeve 2. Since it hardly appears at the start point of the small-diameter portion 31, the adhesive width between the sleeve 2 and the housing 3 can be slightly increased by forming the tapered shape in two steps.

When the magnetic disk rotates in the air at high speed, the magnetic disk receives resistance from the air layer, and the friction generated by the resistance causes the charge generated in the air to be charged on the surface of the magnetic disk. In general, a conductive material is used for a general insulating component so as to release electric charges generated in a magnetic disk of a hard magnetic disk device. As a result, electrostatic breakdown of a magnetic head such as an MR element is eliminated.
By using a conductive adhesive as the adhesive 30, the fixed magnetic disk and the chassis 13 of the apparatus main body are conducted with a low resistance value. Therefore, there is no possibility that static electricity is charged.

In the above description, the housing is the housing of the driving device and is separated from the chassis of the device main body. However, the housing can be similarly implemented even if it is integrated with the main body chassis.

In an HDD using a thin hydrodynamic bearing, the bonding width is inevitably reduced. As shown in FIG. 1 and the like, the adhesive width is further reduced in order to avoid deformation of the crimped portion of the thrust bearing portion. For example, although there is a length of about 3 mm in the axial direction, caulking of the thrust plate (0.5 mm) or the like is performed. For this reason, there may be a case where about 1.5 mm to 2 mm cannot be used due to a thrust bearing in consideration of a relief portion or the like. In this case, the bonding width is about 1 mm, but the two types of adhesive are protruded and the protruding adhesive is irradiated from the bottom side of the housing with ultraviolet light to perform the bonding, including the ultraviolet-curable adhesive. By fastening and fixing the bearing part, the bonding strength enough to withstand high impact resistance could be secured.

As the HDD becomes smaller and thinner, the bonding width of the bearing becomes shorter, and the degree of curing of the adhesive and the degree of curing of the adhesive in a case where the temperature difference in the use environment changes greatly, a heat cycle evaluation test, a high temperature environment, etc. Depending on the type of the adhesive, the adhesive further hardens, and the volatile components contained in the adhesive jump out and change the weight of the adhesive, resulting in a decrease in the amount of the adhesive and the bonding of the bearing member. It is possible to prevent the communication hole with the outside from being formed in the portion by irradiating the ultraviolet rays and curing the adhesive so that the adhesive that touches the air can be cured quickly. Therefore, there is no influence due to uneven application of the adhesive, and sufficient airtightness can be maintained.

Since sufficient airtightness is possible, there is no possibility of deterioration in reliability such as deterioration of contamination conditions inside the HDD. The gap between the magnetic head and the magnetic disk is stabilized, and there is no possibility of an R / W processing error.

[0090]

As is clear from the description of the above embodiment,
The following advantageous effects can be obtained. (1) The adhesive for fixing the sleeve to the housing is caused to protrude from the bonding gap in the bonding step, and the protruding adhesive is cured by heat or ultraviolet rays. Even when the device is ventilated, airtightness of the device can be ensured by sealing with excess adhesive that has protruded. (2) The space other than the adhesive gap is filled and sealed with an adhesive different from the adhesive fixing the sleeve to the housing,
The airtightness of the device can be ensured, and the adhesive 30 also functions as a strength member. (3) Since the tapered small-diameter portion is provided on the sleeve side, the opening is wide toward the outside, so that ultraviolet rays can be stably emitted. (4) Since the effect of caulking and fixing the thrust plate does not appear on the outer diameter of the sleeve, the bonding gap can be reduced, and the assembly process is stabilized. (5) Since the adhesive hardens in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved. (6) The fixed magnetic disk is electrically connected to the chassis of the apparatus main body with a low resistance value by the conductive adhesive. (7) Ultra-small HD of 2.5 inches or less mounted on small notebook computers, mobile computers, and portable terminal devices
D uses a dynamic pressure bearing device for an information recording device of a device that attaches importance to portability, so that it is possible to provide an HDD having a high level of impact resistance that cannot be guaranteed by a ball bearing. (8) An HDD using a hydrodynamic bearing with a thin device can be provided. (9) In an HDD using a thin hydrodynamic bearing, the bonding width is inevitably short, and the fastening strength of the bearing portion of the spindle motor can only be secured in accordance with the bonding width. Further, the adhesive width is further reduced in order to escape deformation of the swaged portion of the thrust bearing portion. For example, although there is a length of about 3 mm in the axial direction, the escape width is reduced due to swaging of a thrust plate (0.5 mm) or the like. In the configuration where about 1.5 mm to 2 mm cannot be used due to the thrust bearing in consideration of the above, the bonding width is about 1 mm, but by bonding and fixing the bearing part with two kinds of adhesives, bonding that can withstand high impact resistance Strength can be secured. (10) As HDDs become smaller and thinner, bonding is frequently used for fastening bearings, and the bonding width is shortened.
Depending on the degree of curing of the adhesive and the type of adhesive in a high-temperature environment, etc., the adhesive further cures, and volatile components contained in the adhesive pop out and change the weight of the adhesive. As a result, there is a communication hole with the outside at the bonding part of the bearing member, and the communication hole connects the inside and the outside without a filter, and also opens at unexpected places. There is no such thing. (11) As a result, there is no risk of deterioration in reliability such as deterioration of contamination conditions inside the HDD. The gap between the magnetic head and the magnetic disk is stabilized, and there is no possibility of an R / W processing error. (12) Since the two types of adhesives are hardened in the space between the sleeve and the housing, the fastening length between the sleeve and the housing is increased, and the fastening strength of the bearing device is improved. (13) The above-described effects can be obtained by adopting the manufacturing method as described in claims 2, 4, 5, 8, and 10.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fixed magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is an enlarged explanatory view showing a state in which a sleeve is adhesively fixed to a housing.

FIG. 3 is an enlarged explanatory view of a state in which a sleeve is bonded and fixed to a housing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor hub 2 Sleeve 3 Housing 4 Thrust plate 5 Stator core 6 Drive magnet 7 Fixed magnetic disk 8 Clamper 9 Screw 10 Flange part 11 Internal cylindrical part 12 External cylindrical part 13 Chassis 14 Coil 15, 18, 18a, 30 Adhesive 16 Disk receiving surface Reference Signs List 17 Cylindrical portion for regulating disk inner diameter 19 Retaining plate 20 Shaft 21, 22 Cylindrical portion of sleeve 23 Fluid holding portion 24, 26 Space 25 Flexible printed circuit board 27 Tapered small diameter portion of sleeve 28 Tapered portion of housing 29 Seat 31, 32 Tapered small diameter part of sleeve

Claims (10)

[Claims] 1. A housing, a sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, and mounted directly or indirectly to the rotor hub. And a stator core disposed opposite to the drive magnet, wherein the shaft rotates with a lubricating fluid relative to the sleeve, wherein a fixed magnetic disk is mounted on a rotor hub. , Fix the thrust plate to one end of the sleeve, fasten the sleeve and the housing with adhesive, irradiate the adhesive protruding on the thrust plate side with ultraviolet rays and cure, and use the adhesive to seal the airtightness between the housing and the sleeve. A fixed magnetic disk drive device characterized by being performed. 2. A housing, a sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, and mounted directly or indirectly to the rotor hub. A driving magnet, and a stator core disposed to face the driving magnet, wherein the shaft is a driving device that rotates through a lubricating fluid with respect to the sleeve. A stator assembly fixed to the housing is made, a shaft is fastened and fixed to the rotor hub, and a hub assembly is formed by gluing and fixing the magnetized drive magnet, and then a thrust plate is fixed to the sleeve by swaging. After the assembly is completed, a predetermined amount of lubricating fluid is instilled at a predetermined position on the inner peripheral portion of the sleeve of the bearing assembly. Then, insert the shaft of the hub assembly into the sleeve, then fix the retaining plate to the rotor hub, apply adhesive to the inner peripheral portion of the inner cylindrical portion of the housing of the stator assembly, and insert the sleeve. Then, the distance between the reference surface of the housing and the fixed magnetic disk receiving surface of the rotor hub is adhered and fixed so as to be a specified value, and the adhesive which has protruded to the thrust plate side is irradiated with ultraviolet rays to be hardened, and the housing and the sleeve are bonded together. A method for manufacturing a fixed magnetic disk drive, wherein airtightness is performed with an adhesive. 3. A housing, a sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, and mounted directly or indirectly to the rotor hub. And a stator core disposed opposite to the drive magnet, wherein the shaft rotates with a lubricating fluid relative to the sleeve, wherein a fixed magnetic disk is mounted on a rotor hub. , A thrust plate is fixed to one end of the sleeve, the sleeve and the housing are fastened with an adhesive (adhesive a), and a gap between the sleeve and the housing on the thrust plate side is made of an ultraviolet-curing adhesive (adhesive b). ) Is cured by irradiating the housing with the sleeve with two kinds of adhesives (the adhesive a). The fixed magnetic disk drive is characterized in that the adhesive (b) is made with another adhesive). 4. A housing, a sleeve fixed to the housing, a rotor hub rotatable relative to the housing, a shaft fastened to the rotor hub, and mounted directly or indirectly to the rotor hub. And a stator core disposed opposite to the drive magnet, wherein the shaft is a drive device that rotates via a lubricating fluid with respect to the sleeve. A stator assembly fixed to the housing is made, a shaft is fastened and fixed to the rotor hub, and a hub assembly is formed by gluing and fixing the magnetized drive magnet, and then a thrust plate is fixed to the sleeve by swaging. Build an assembly,
Next, lubricating fluid was injected into a predetermined position of the inner peripheral portion of the sleeve of the bearing assembly, the shaft of the hub assembly was inserted into the sleeve, and then the retaining plate was fixed to the rotor hub,
An adhesive (adhesive a) is applied to the inner peripheral portion of the inner cylindrical portion of the stator assembly housing, a sleeve is inserted, and the distance between the reference surface of the housing and the fixed magnetic disk receiving surface of the rotor hub is defined. And the gap between the sleeve on the thrust plate side and the housing is cured by irradiating ultraviolet rays to an ultraviolet curable adhesive (referred to as adhesive b) to cure the airtightness between the housing and the sleeve. A method for manufacturing a fixed magnetic disk drive, wherein two types of adhesives are used (an adhesive a and an adhesive b are different adhesives). 5. The fixed magnetic disk drive according to claim 3, wherein the viscosity of the adhesive a is greater than the viscosity of the adhesive b. 6. The fixed magnetic disk drive according to claim 3, wherein the adhesive mainly having airtightness is a conductive adhesive and is of an ultraviolet curing type. 7. A fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and the sleeve is fixed to a housing by bonding, the thrust plate is swaged to a seat surface of the sleeve. The beginning of the small diameter portion that is fixed and smaller than the bonding outer diameter of the sleeve on the swaging-side sleeve is located closer to the inside of the motor than the seating surface, and the adhesive is applied to the gap formed by the smaller diameter portion and the housing. 6. The fixed magnetic disk drive according to claim 1, wherein airtightness between the housing and the sleeve is ensured by interposing. 8. A fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and this sleeve is fixed to a housing by bonding, the thrust plate is swaged to a seat surface of the sleeve. The beginning of the small diameter portion that is fixed and smaller than the bonding outer diameter of the sleeve on the swaging-side sleeve is located closer to the inside of the motor than the seating surface, and the adhesive is applied to the gap formed by the smaller diameter portion and the housing. 5. The method according to claim 2, wherein airtightness between the housing and the sleeve is ensured by interposing. 9. A fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing, and the sleeve is fixed to a housing by bonding, the thrust plate is swaged to a bearing surface of the sleeve. The beginning of the small diameter portion which is fixed and has a diameter smaller than the bonding outer diameter of the sleeve on the caulking side is located closer to the inside of the motor than the seating surface, and the smaller diameter portion is tapered. The airtightness between the housing and the sleeve is secured by interposing an adhesive in a gap defined by the two tapered portions and the housing, and by interposing an adhesive therebetween. 6. The fixed magnetic disk drive according to any one of claims 1, 3, and 5. 10. A fixed magnetic disk drive in which a thrust plate is fixed to one end of a sleeve to form a bottomed bearing and the sleeve is fixed to a housing by bonding, the thrust plate is swaged to a bearing surface of the sleeve. The beginning of the small diameter portion which is fixed and has a diameter smaller than the bonding outer diameter of the sleeve on the caulking side is located closer to the inside of the motor than the seating surface, and the smaller diameter portion is tapered. The airtightness between the housing and the sleeve is ensured by interposing an adhesive in a gap formed by the two tapered portions and the housing, with an adhesive interposed therebetween. Or the method of manufacturing the fixed magnetic disk drive according to 4.