JP2003161316A - Head stuck assembly and method for mounting bearing unit on the head stuck assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a head stuck assembly excellent in such durability and stability as to have less possibility of variation in mounting-rigidity of a bearing unit and functional damage of a plurality of bearings, and further provide a method for mounting the bearing unit on the head stuck assembly. <P>SOLUTION: There are provided a bearing unit 100 comprising a plurality of bearings preloaded in an axial direction in a state where the bearings are fitted into a shaft 108 and a block body 4 formed with a fitting hole 4a into which the bearing unit can be fitted. The block body is supported in a freely oscillating and freely rotating manner via the bearing unit. After the bearing unit is inserted into the fitting hole in a state in which heat treatment is continuously applied at least to an adjacent section of the fitting hole until an inner diameter of the fitting hole of the block body becomes larger than an outer diameter of the bearing unit and then the predetermined temperature is kept, cooling treatment is applied to the heated section of the block body which has risen in temperature due to heating and thereby the bearing unit is made to be mounted on the block body via the fitting hole. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head stack assembly in which a bearing unit including a plurality of bearings that are axially loaded (preloaded) is mounted, and a method of mounting the bearing unit in the head stack assembly.

[0002]

2. Description of the Related Art For example, a storage device (hard disk drive) of information equipment is provided with a disk for storing information, a spindle motor for rotating the disk, and a head stack assembly. The head stack assembly includes a head for recording and reproducing information on and from a disk, a block body for mounting the head on the head stack assembly, a bearing unit for supporting the block body in a swingable and rotatable manner, and a block body. And a voice coil that swings to a desired position. A bearing unit mounted on such a head stack assembly is composed of a plurality of bearings that are axially loaded (preloaded). FIGS. 6A to 6F show an example of the structure of a generally known bearing unit, each of which is composed of two bearings. Specifically, in the bearing unit 100 shown in FIG. 1A, the two bearings are respectively provided in inner rings 102a and 102b, outer rings 104a and 104b, and a plurality of rolling bearings provided between the inner and outer rings. The rolling element 106 is inserted between the shaft 108 and the housing 110, and the housing 110
Includes a stepped portion 110a protruding inward at the central portion in the axial direction.
Are integrally formed. Then, the outer ring side surfaces of the bearing are brought into contact with the axially opposite side surfaces of the step portion 110a, respectively.
a and 104b are fixed (fitted) to the housing 110 and pressed in the axial direction with the inner rings 102a and 102b fitted to the shaft 108, whereby a predetermined pressing force (preload) is applied to the two bearings. ) Is loaded. In the bearing unit 112 shown in FIG. 7B, according to the improvement of FIG. 3A, an annular spacer 114 is provided instead of integrally forming the step portion 110a in the housing 110. The bearing unit 116 shown in FIG. 7C is modified from that of FIG. 1B and is formed by removing the housing 110. Bearing unit 11 shown in FIG.
8 relates to the improvement of FIG. 7C, and the annular spacer 114 is removed, and the outer rings 104a and 104b of the two bearings are integrated with each other to form one outer ring 120. The bearing unit 122 shown in (e) of FIG.
The inner ring 102b of one of the bearings is removed, and instead the shaft 108 is partially thickened, and the raceway grooves 124 of the plurality of rolling elements 106 are formed on the outer circumference thereof. . Bearing unit 1 shown in FIG.
26 is related to the improvement of FIG.
The outer ring 104 of the two bearings so that the annular spacer 114 is removed to fill the empty area.
Each of a and 104b is extended in the axial direction and abutted against each other. In addition to these configuration examples, for example, the bearing units 118, 122, 1 shown in FIGS.
26 is a housing 11 as shown in FIGS.
It is also known that 0 is fitted.

[0003]

By the way, the bearing units 100, 112, 116, 118, 12 as described above are provided.
2,126 head stack assembly (block body)
As a method of attaching the same to the above, for example, methods such as press fitting, adhesion, screwing and the like are generally used. In the press-fitting method, a fitting hole with a diameter slightly smaller than the outer diameter of the bearing unit is formed in the block body, and the bearing unit is press-fitted into this fitting hole with a interference, and the bearing unit is fitted into the fitting hole of the block body. I am wearing it. In this case, an annular member (for example, a tolerance ring) may be interposed between the bearing unit and the fitting hole. According to such a press-fitting method, when the bearing unit is press-fitted into the fitting hole, the bearing unit slides in the fitting hole to generate abrasion powder, and further, when the tightening margin is large, it becomes powdery. A foreign object of the size of is also generated. And
If dust such as abrasion powder or foreign matter enters the inside of the bearing, it may cause functional damage to the bearing (for example, increase or fluctuation of torque, generation of torque spike, deterioration of durability due to wear of rolling elements or bearing rings). is there. Further, if dust adheres to the disk surface or the head surface, the disk surface or the head surface may be damaged. In the bonding method, a fitting hole with a diameter slightly larger than the outer diameter of the bearing unit is formed in the block body, and an adhesive agent is interposed in the gap between the bearing unit and the fitting hole to fit the bearing unit to the block body. It is attached to the hole. According to such a bonding method, the shaft center of the bearing unit and the center of the fitting hole may deviate during mounting, and in that case, the bearing unit is bonded in a biased state with respect to the fitting hole. . As a result, the mounting rigidity between the bearing unit and the fitting hole (block body) tends to vary, and the reliability of the entire head stack assembly may decrease. In the screwing method, for example, as shown in FIGS. 7 and 8, the block body 130 is provided with the fitting hole 128 having a diameter slightly larger than the outer diameter of the bearing unit 100.
The bearing unit 100 is tightly attached to the fitting hole 128 by pressing or pulling the bearing unit 100 with the screw 132, and the bearing unit 100 is attached to the fitting hole 128 of the block body 130. Note that FIG.
In the screwing method shown in (1), the bearing unit 100 is pressed in the radial direction by the screw 132 to bring the bearing unit 100 into close contact with the inner surface of the fitting hole 128. On the other hand, according to the screw fastening method shown in FIG. 8, the bearing unit 100 is pulled in the radial direction by the screw 132 so that the bearing unit 100 is fitted into the fitting hole 12.
It adheres to the inner surface of 8. Further, although the bearing unit 100 is illustrated in the drawing, another bearing unit 11
It may be 2,116,118,122,126. According to such a screwing method, only one surface of the bearing unit 100 is in contact with the fitting hole 128 (line contact or partial surface contact). In this case, the mounting rigidity between the bearing unit and the fitting hole (block body) is low and unstable, and as a result, the reliability of the entire head stack assembly may decrease. As a measure to solve this, for example, a plurality of convex portions are provided on the inner surface of the fitting hole 128, and a plurality of contact points with the bearing unit 100 for the fitting hole 128 are provided to stabilize the mounting rigidity. Can also be considered. However, in such a measure, the contact force of the bearing unit 100 with respect to the plurality of protrusions causes functional damage (for example, deformation of the bearing) of the bearing, which is one component of the bearing unit 100, and as a result, fluctuations in the torque of the bearing. Or torque spikes may occur. The present invention has been made to solve such a problem, and an object thereof is excellent in durability and stability without causing variations in mounting rigidity of bearing units and functional damage of a plurality of bearings. (EN) A head stack assembly and a method for mounting a bearing unit on the head stack assembly.

[0004]

In order to achieve such an object, the present invention provides a bearing unit comprising a plurality of bearings which are preloaded in the axial direction in a state of being fitted to the shaft, and the bearing unit. In a head stack assembly in which a block body having a fitting hole in which a unit can be mounted is formed, and the block body is rotatably supported by a bearing unit, the inner diameter of the fitting hole of the block body is a bearing. After the bearing unit is inserted into the fitting hole with at least the peripheral area of the fitting hole being heat-treated and kept at a predetermined temperature until it becomes larger than the outer diameter of the unit, the temperature rises due to heating. The bearing unit is attached to the block body through the fitting hole by cooling the heated portion of the block body. Further, the present invention includes a bearing unit including a plurality of bearings that are preloaded in the axial direction in a state of being fitted to the shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In the method of mounting the bearing unit on the head stack assembly, in which the block body is swingably and rotatably supported via the bearing unit, at least until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit. A process of heat-treating the area around the fitting hole and maintaining it at a predetermined temperature, a step of inserting the bearing unit into the fitting hole, and a cooling process on the heating portion of the block body that is heated and the temperature is rising. And a step of applying.
The above invention includes a configuration in which the adhesive is wholly or partially applied to one or both of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit. This configuration also includes a case where a concave adhesive groove for applying an adhesive is formed on one or both of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit. In the above invention, the interference portion is secured on one of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit so that the outer diameter of the bearing unit is larger than the inner diameter of the fitting hole of the block body. Includes configuration. In this configuration, the interference portion is secured by disposing the interposing member on the outer periphery of the bearing unit or the inner periphery of the fitting hole of the block body. In the above invention, as the cooling treatment, a natural cooling treatment for naturally cooling the heated portion of the block body which is heated and the temperature is raised, or a forced heated portion of the block body which is heated and the temperature is raised. It is possible to apply a forced cooling process for cooling the film. In this case, in the forced cooling process, a direct cooling process for directly cooling the heated part of the block body that is heated and the temperature is rising, or an indirect cooling of the heated part of the block body that is heated and the temperature is rising. It is possible to apply an indirect cooling process in which the light is cooled. The indirect cooling process includes a case in which the bearing unit is cooled to indirectly cool the heated portion of the block body which is heated and the temperature of which is increased.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A head stack assembly according to a first embodiment of the present invention will be described below with reference to FIG. In the head stack assembly of this embodiment, the bearing units are the above-mentioned bearing units 100, 112, 116, 118, 122, 12
6 (see FIG. 6) can be applied. In the following description, the case where the bearing unit 100 is applied is assumed as an example.

As shown in FIG. 1, the head stack assembly according to the present embodiment includes a bearing unit 100 composed of a plurality of bearings which are preloaded in the axial direction in a state of being fitted to the shaft 108, and this bearing unit. A block body 4 having a fitting hole 4a into which 100 can be mounted, and the block body 4
And a voice coil 6 that swings and rotates to a desired position. The block body 4 is swingably and rotatably supported about a shaft 108 via a bearing unit 100, and a head (not shown) for recording and reproducing information on, for example, a disc (not shown) can be attached to the block body 4. Has become. Then, by driving the voice coil 6 to swing and rotate the block body 4, the head can be scanned along the recording / reproducing track of the disk. In such a configuration, as a method of mounting the bearing unit 100 in the head stack assembly, at least the peripheral region of the fitting hole 4a is formed until the inner diameter of the fitting hole 4a of the block body 4 becomes larger than the outer diameter of the bearing unit 100. The bearing unit 10 is subjected to heat treatment and kept at a predetermined temperature.
After inserting 0 into the fitting hole 4a, the bearing unit 100 is mounted on the block body 4 through the fitting hole 4a by cooling the heating portion of the block body 4 that is heated and the temperature is rising. Can be made. The materials, shapes, and dimensions of the block body 4 and the voice coil 6 can be arbitrarily set according to the purpose of use, the environment of use, and the like.

The heat treatment is not performed on the bearing unit 100, which requires a highly accurate operation, but is performed on at least the peripheral region of the fitting hole 4a. In this case, block body 4
The heat treatment may be limited to the peripheral area of the fitting hole 4a, or the heat treatment may be uniformly performed on the entire block body 4. Either way, the fitting hole 4a of the block body 4
Is subjected to heat treatment and kept at a predetermined temperature until the inside diameter of the bearing unit 100 becomes larger than the outside diameter of the bearing unit 100. Since the heating temperature is appropriately adjusted according to the material, shape and size of the block body 4, the heating temperature is not particularly limited here. In addition, during the heat treatment, when components such as the voice coil 6 and the head are already attached to the block body 4, the attachment means (adhesive member such as resin) between each of these components and the block body 4 is used. In order to prevent deterioration and functional damage to the head, it is preferable to use a method of lowering the heating temperature, limiting the heating area, or locally heating and forcibly cooling the other area. As the cooling process, the block body 4 that is heated and the temperature is rising
It is possible to apply a natural cooling process of naturally cooling the heated part of the above, or a forced cooling process of forcibly cooling the heated part of the block body 4 which has been heated and whose temperature is rising. As for the heating portion of the block body 4, since the thermal conductivity varies depending on the material, shape and size of the block body 4, for example, even if the heating treatment is performed only in the peripheral region of the fitting hole 4a, the heating portion is not heated. When staying in the area around the fitting hole 4a,
In some cases, the heating portion may spread over the entire block body 4 beyond this region. In any case, in the natural cooling process, the heat-treated head stack assembly is left as it is to be cooled by the heat radiation. On the contrary,
In the forced cooling process, the heating portion of the block body 4 is directly or indirectly cooled by a predetermined cooling device (direct cooling process or indirect cooling process). As the cooling device used for the forced cooling process, various cooling devices that are currently used can be applied, and therefore the cooling device is not particularly limited here. Further, in the forced cooling process, a direct cooling process for directly cooling the heated part of the block body 4 that is heated and the temperature is raised, or a heated part of the block body 4 that is heated and the temperature is raised. An indirect cooling process of indirectly cooling can be applied. And in the indirect cooling process,
By cooling the bearing unit 100, the heated portion of the block body 4 which is heated and whose temperature is rising is indirectly cooled. In this indirect cooling process, the bearing unit 1
When 00 is cooled, the cooling action is transmitted to the block body 4 via the fitting hole 4a, and as a result, the heated portion of the block body 4 is cooled. When such a cooling process is completed, the inner diameter of the fitting hole 4a of the block body 4 which is heated and expanded is contracted, and at that time, the bearing unit 100 is sandwiched by the fitting hole 4a. Becomes As a result, the bearing unit 100 is mounted on the block body 4 through the fitting hole 4a.

As described above, according to the present embodiment, when the bearing unit 100 is mounted on the head stack assembly, only the process of inserting the bearing unit 100 into the fitting hole 4a of the block body 4 is performed. There is no need to slide it. In this case, since no abrasion powder or cutting dust-like foreign matter is generated, functional damage of a plurality of bearings constituting the bearing unit 100 (for example, increase or fluctuation of torque, occurrence of torque spike, wear of rolling elements or races) It does not cause deterioration of durability). As a result, it is possible to realize a head stack assembly having excellent stability without causing functional damage to the bearing. Further, since the shrinkage rate of the fitting hole 4a during cooling is uniform, the inner diameter of the fitting hole 4a shrinks so that the bearing unit 100 is fitted into the fitting hole 4a.
When sandwiched by, the shaft center of the bearing unit 100 and the center of the fitting hole 4a are maintained in a state of being aligned with each other. In this case, the bearing unit 100 is not bonded in a biased state with respect to the fitting hole 4a unlike the conventional case. As a result, it is possible to realize a head stack assembly having excellent durability with little variation in mounting rigidity between the bearing unit 100 and the fitting hole 4a (block body 4).
Further, the inner diameter of the fitting hole 4a shrinks, and the bearing unit 100
The bearing unit 1 when it is sandwiched by the fitting holes 4a.
00 is maintained in a state of being in surface contact with the entire inner surface of the fitting hole 4a. In this case, the mounting rigidity between the bearing unit 100 and the fitting hole 4a (block body 4) can be kept uniform and high. As a result, it is possible to realize a head stack assembly excellent in durability and stability with less variation in mounting rigidity of the bearing unit 100.

The present invention is not limited to the above-described first embodiment, and various modifications can be made. For example, in FIG. 2, the above-mentioned bearing unit 100,
The structure of the head stack assembly to which the bearing unit 116 is applied is shown among 112, 116, 118, 122, 126 (see FIG. 6). Even in this case, it is possible to realize the effects of the first embodiment described above.

Next, a head stack assembly according to a second embodiment of the present invention will be described with reference to FIG. In the head stack assembly of this embodiment, the bearing units are the above-mentioned bearing units 100, 112, 116, 118, 122, 126 (see FIG. 6).
It is possible to apply). In the explanation below,
As an example, it is assumed that the bearing unit 100 is applied. As shown in FIG. 3, in the head stack assembly of the present embodiment, the adhesive 8 is wholly or partially applied to either or both of the inner surface of the fitting hole 4a of the block body 4 and the outer surface of the bearing unit 100. Is applied to.
In the drawings, as an example thereof, the adhesive 8 is provided with the bearing unit 1.
No. 00 is applied to the entire outer surface. With such a configuration, the mounting force of the bearing unit 100 in the head stack assembly (fitting hole 4a of the block body 4) can be improved. As a result,
It is possible to realize a head stack assembly excellent in durability and stability with less variation in mounting rigidity of the bearing unit. Also, the block body 4
It is also preferable to form a concave adhesive groove (not shown) for applying the adhesive 8 on one or both of the inner surface of the fitting hole 4a and the outer surface of the bearing unit 100. By forming such an adhesive groove, the adhesive 8 can be applied stably and surely, so that the mounting force of the bearing unit 100 to the head stack assembly (fitting hole 4a of the block body 4) is further improved. Can be made. The rest of the configuration, functions, and effects are the same as those of the first embodiment described above, so description thereof will be omitted.

Next, a head stack assembly according to a third embodiment of the present invention will be described with reference to FIG. In the head stack assembly of this embodiment, the bearing units are the above-mentioned bearing units 100, 112, 116, 118, 122, 126 (see FIG. 6).
It is possible to apply). In the explanation below,
As an example, it is assumed that the bearing unit 100 is applied. As shown in FIG. 4, in the head stack assembly of the present embodiment, the fitting hole 4a of the block body 4 is formed so that the outer diameter of the bearing unit 100 is larger than the inner diameter of the fitting hole 4a of the block body 4. The interference portion 10 is secured on either the inner surface or the outer surface of the bearing unit 100. The other configuration is the same as that of the first embodiment described above, and therefore its description is omitted. In the present embodiment, the interference portion 10 is secured by disposing an interposing member on the outer periphery of the bearing unit 100. In this case, the material, shape, dimensions, etc. of the interposition member (clamping margin portion) 10 can be arbitrarily selected according to the purpose of use, environment of use, etc., and are not particularly limited here. Further, as a mounting method of the bearing unit 100 in which the interposition member (clamping margin portion) 10 is secured on the outer periphery, the above-described first and second embodiments can be applied,
The operational effects obtained when these embodiments are applied are the same as those of the first and second embodiments, and therefore the description thereof is omitted. In addition, in the present embodiment, the interference portion 10 is secured on the outer periphery of the bearing unit 100, but the invention is not limited to this. For example, as shown in FIG. 5, the block body 4 is used as the interference portion. The interposition member 10 may be arranged on the inner circumference of the fitting hole 4a. In this case, after mounting the interposing member (clamping margin) 10 in the fitting hole 4a, the bearing unit 1
00 may be attached by the same method as in the first and second embodiments. Further, in the case where the tightening margin is not only the interposing member but also the housing such as the bearing units 100 and 112, the housing outer diameter is set to be larger than the inner diameter of the fitting hole 4a of the block body 4. It can also be applied. In addition, the bearing units 116, 118, 122,
In the case where there is no housing such as 126, the outer diameter of the outer ring can be set larger than the inner diameter of the fitting hole 4a of the block body 4 as well.

[0012]

According to the present invention, a head stack assembly and a bearing unit for a head stack assembly which are excellent in durability and stability without causing variations in mounting unit mounting rigidity and functional damage of a plurality of bearings are provided. Can be installed.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a head stack assembly and a mounting method of a bearing unit according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a head stack assembly and a method of mounting a bearing unit according to a modified example of the first embodiment.

FIG. 3 is a diagram showing a configuration of a head stack assembly and a bearing unit mounting method according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a head stack assembly and a bearing unit mounting method according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a head stack assembly and a mounting method of a bearing unit according to a modified example of the third embodiment.

6A to 6F are cross-sectional views showing the configuration of a bearing unit, respectively.

FIG. 7 is a diagram showing a method of mounting the bearing unit to which a screwing method of pressing the bearing unit with a screw is applied.

FIG. 8 is a diagram showing a mounting method of the bearing unit to which a screwing method of pulling the bearing unit with a screw is applied.

[Explanation of symbols]

4: Block body 4a: Fitting hole 100: Bearing unit 108: axis

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J017 AA01 AA06 BA10 CA01 DA10                       DB10                 3J101 AA02 AA42 AA52 AA63 AA72                       AA81 BA53 DA16 FA04 FA31                       FA46 GA53                 5D068 AA01 BB02 CC12 GG03

Claims (18)

[Claims] 1. A bearing unit comprising a plurality of bearings that are preloaded in the axial direction in a state of being fitted to a shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In the head stack assembly, in which the block body is swingably and rotatably supported by the bearing unit, at least the area around the fitting hole is heated until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit. After the treatment is performed and the temperature is kept at a predetermined temperature, the bearing unit is inserted into the fitting hole, and then the heating portion of the block body that is heated and the temperature is increased is cooled.
The head stack assembly, wherein the bearing unit is attached to the block body through a fitting hole. 2. A bearing unit comprising a plurality of bearings which are preloaded in the axial direction in a state of being fitted to a shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In a head stack assembly in which a block body is swingably and rotatably supported via a bearing unit, an adhesive is wholly or partially applied to either or both of an inner surface of a fitting hole of the block body and an outer surface of a bearing unit. Of the bearing unit while applying heat treatment to at least the peripheral area of the fitting hole until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit and the temperature is maintained at a predetermined temperature. After inserting into the fitting hole, the bearing unit is mounted on the block body through the fitting hole by cooling the heated part of the block body that is heated and the temperature is rising. A head stack assembly characterized in that 3. A concave adhesive groove for applying an adhesive is formed on one or both of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit. 2. The head stack assembly according to item 2. 4. A bearing unit comprising a plurality of bearings which are preloaded in the axial direction in a state of being fitted to the shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In a head stack assembly in which the block body is swingably and rotatably supported via a bearing unit, the inner surface of the fitting hole of the block body is adjusted so that the outer diameter of the bearing unit is larger than the inner diameter of the fitting hole of the block body. Also, a fitting margin is secured on one of the outer surfaces of the bearing unit, and at least the peripheral area of the fitting hole is subjected to heat treatment until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit. After the bearing unit is inserted into the fitting hole while keeping it at a predetermined temperature, the heating unit of the block body, which has been heated and the temperature is rising, is subjected to cooling treatment, thereby Is attached to the block body through a fitting hole. 5. The head stack assembly according to claim 4, wherein the interference portion is secured by disposing an interposing member on the outer periphery of the bearing unit. 6. The head stack assembly according to claim 4, wherein the interference portion is secured by disposing an interposing member on the inner circumference of the fitting hole of the block body. 7. As the cooling treatment, a natural cooling treatment for naturally cooling the heated portion of the block body which is heated and the temperature is raised, or a forced heated portion of the block body which is heated and the temperature is raised. The head stack assembly according to any one of claims 1 to 6, wherein a forced cooling process for cooling the head stack is applicable. 8. In the forced cooling treatment, a direct cooling treatment for directly cooling a heated portion of the block body which is heated and the temperature thereof is raised, or a heated portion of the block body which is heated and has a raised temperature. The head stack assembly according to claim 7, wherein an indirect cooling process for indirectly cooling the head stack assembly can be applied. 9. The head according to claim 8, wherein, in the indirect cooling process, the bearing unit is cooled to indirectly cool the heated portion of the block body which is heated and the temperature of which is increased. Stack assembly. 10. A bearing unit comprising a plurality of bearings preloaded in the axial direction in a state of being fitted to a shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In the method of mounting the bearing unit on the head stack assembly, in which the block body is swingably and rotatably supported via the bearing unit, at least until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit. A process of heat-treating the area around the dowel hole and maintaining it at a predetermined temperature, a process of inserting the bearing unit into the fitting hole, and a cooling process on the heated portion of the block body that is heated and the temperature is rising. And a step of applying the bearing unit to the head stack assembly. 11. A bearing unit comprising a plurality of bearings preloaded in the axial direction in a state of being fitted to a shaft, and a block body having a fitting hole into which the bearing unit can be mounted. In the method of mounting the bearing unit to the head stack assembly, in which the block body is swingably and rotatably supported via the bearing unit, the block body is bonded to one or both of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit. Apply the agent in whole or in part, and at least heat the peripheral area of the fitting hole until the inner diameter of the fitting hole of the block becomes larger than the outer diameter of the bearing unit, and keep it at the specified temperature. A holding step, a step of inserting the bearing unit into the fitting hole, and a step of cooling the heated portion of the block body that is heated and whose temperature is rising. How to install the bearing unit in the dead stack assembly. 12. A concave adhesive groove for applying an adhesive is formed on one or both of the inner surface of the fitting hole of the block body and the outer surface of the bearing unit. 11. The method for mounting the bearing unit on the head stack assembly according to item 11. 13. A bearing unit comprising a plurality of bearings preloaded in the axial direction in a state of being fitted to a shaft, and a block body having a fitting hole into which the bearing unit can be mounted. The block body is swingably and rotatably supported via the bearing unit. When mounting the bearing unit on the head stack assembly, the block is arranged so that the outer diameter of the bearing unit is larger than the inner diameter of the fitting hole of the block body. The process of securing the interference area on either the inner surface of the body fitting hole or the outer surface of the bearing unit, and at least until the inner diameter of the fitting hole of the block body becomes larger than the outer diameter of the bearing unit. A process of heat-treating the peripheral region and maintaining it at a predetermined temperature, and after inserting the bearing unit into the fitting hole, cool the heated portion of the block body that is heated and the temperature is rising. Method of mounting the bearing unit to the head stack assembly and having a to process. 14. The method of mounting a bearing unit in a head stack assembly according to claim 13, wherein the interference portion is secured by disposing an interposing member on the outer periphery of the bearing unit. 15. The bearing unit for a head stack assembly according to claim 13, wherein the interference portion is secured by disposing an interposing member on the inner periphery of the fitting hole of the block body. How to wear. 16. The cooling treatment includes a natural cooling treatment for naturally cooling a heated portion of the block body which is heated and the temperature thereof is raised, or a forced heating portion of the block body which is heated and has a raised temperature. 11. It is possible to apply a forced cooling process for cooling the film selectively.
16. A method for mounting the bearing unit on the head stack assembly according to any one of 1 to 15. 17. In the forced cooling treatment, a direct cooling treatment for directly cooling a heated portion of a block body which is heated and the temperature thereof is raised, or a heated portion of a block body which is heated and has a raised temperature. 16. An indirect cooling process for indirectly cooling a can be applied.
A method for mounting the bearing unit on the head stack assembly according to. 18. The head according to claim 17, wherein, in the indirect cooling process, the bearing unit is cooled to indirectly cool the heated portion of the block body which is heated and the temperature of which is increased. How to install the bearing unit in the stack assembly.