JP2005016556A - Conical dynamic pressure bearing device, and recording disk drive device having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize a conical dynamic pressure bearing device, and to excellently enhance the performance thereof at a low cost. <P>SOLUTION: In the conical dynamic pressure bearing device, a fluid pressurizing means 13e to pressurize a lubrication fluid in the pressing direction toward the inner side of an inclined bearing space BS is continuously provided on an opening part located on the outer circumferential side of the substantially conical inclined bearing space BS formed in a space between both inclined dynamic pressure surfaces of a bearing sleeve 13 and a shaft bush 21, the pressurized lubrication fluid is pressed into the inner side from the outer circumferential side of the inclined bearing space BS by the fluid pressurizing means 13e to excellently generate the dynamic pressure in the lubrication fluid in the inclined bearing space BS irrespective of the opening angle of the inclined dynamic pressure surfaces, and the lubrication fluid to flow outwardly from the opening part on the outer circumferential side of the inclined bearing space BS is stably held in the inclined bearing space BS by the rotational centrifugal force. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a conical hydrodynamic bearing device configured to rotatably support a shaft bush formed in a substantially conical shape and a bearing sleeve in a non-contact manner while floating relative to each other by the dynamic pressure of a lubricating fluid. The present invention relates to a recording disk drive device.
[0002]
[Prior art]
In recent years, development of a hydrodynamic bearing device capable of stably supporting various rotating bodies at high speed has been promoted. In the conical type (conical type) hydrodynamic bearing device, a shaft bush having a substantially conical inclined dynamic pressure surface is inserted into a bearing sleeve having a substantially conical inclined dynamic pressure surface so as to be relatively rotatable. In addition, an inclined bearing space having a substantially conical shape is formed in a gap between the inclined dynamic pressure surface of the shaft bush and the inclined dynamic pressure surface of the bearing sleeve, and lubrication made of lubricating oil or the like is formed in the inclined bearing space. Filled with fluid.
[0003]
And, at least one side of the both inclined dynamic pressure surfaces of the shaft bush and the bearing sleeve is provided with dynamic pressure generating means having an appropriately shaped concave groove structure or the like, and the relative rotation between the shaft bush and the bearing sleeve is achieved. Sometimes, the dynamic fluid is pressurized by the dynamic pressure generating means to generate a dynamic pressure in the lubricating fluid, and the dynamic pressure of the lubricating fluid is used to move the shaft bush and the bearing sleeve in both the radial direction and the thrust direction. It is made the structure which carries out rotation support by non-contact by making it float relatively (for example, refer patent documents 1-4).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-7886 [Patent Document 2]
Japanese Patent Laid-Open No. 10-339318 [Patent Document 3]
JP 2002-174226 A [Patent Document 4]
JP 2003-97547 A
As described above, in the conical type (conical type) dynamic pressure bearing device, both dynamic pressure surfaces formed on the bearing sleeve and the shaft bush are formed in a surface inclined substantially conically with respect to the rotation shaft. In order to stably ensure the relative flying height between the fixed member and the rotating member, the above-described opening angle of the inclined dynamic pressure surface, that is, the angle corresponding to the apex angle of the conical shape of the inclined dynamic pressure surface, It is preferable to set as large as possible so that the dynamic pressure in the thrust direction is increased.
[0006]
[Problems to be solved by the invention]
However, the structure in which the opening angle of the inclined dynamic pressure surface is set to be large depends on the size of the entire device in the radial direction. I can't. Moreover, if the opening angle of the inclined dynamic pressure surface is excessively large, the dynamic pressure in the radial direction may be insufficient, leading to a decrease in bearing rigidity.
[0007]
Furthermore, by setting the opening angle of the inclined dynamic pressure surface to be large, the rotational centrifugal force at the outer peripheral side portion of the inclined bearing space increases, and the acting force due to the rotational centrifugal force is greater than the fluid holding force of the fluid seal portion. Even when the fluid seal portion is provided, the lubricating fluid may leak to the outside.
[0008]
Accordingly, the present invention can stably and reliably obtain a good relative flying height without increasing the opening angle of the inclined dynamic pressure surface, and can satisfactorily prevent leakage of lubricating fluid from the inclined bearing space. It is an object of the present invention to provide a conical type (conical type) hydrodynamic bearing device and a recording disk drive device including the same.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, in the conical dynamic pressure bearing device according to claim 1 of the present invention, the inclined bearing space having a substantially conical shape formed in the opposed gap between the inclined dynamic pressure surfaces of the bearing sleeve and the shaft bush is provided. In addition, a fluid seal portion that prevents external leakage of the lubricating fluid in the inclined bearing space is continuously provided, and the lubricating fluid is directed toward the inner side of the inclined bearing space between the inclined bearing space and the fluid seal portion. Fluid pressurizing means for pressurizing in the pushing direction is provided.
According to the conical hydrodynamic bearing device according to claim 1 having such a configuration, the lubricating fluid pressurized by the fluid pressurizing means is pushed from the outer peripheral side of the inclined bearing space toward the inner side. Therefore, the dynamic pressure is generated in the lubricating fluid in the inclined bearing space regardless of the opening angle of the inclined dynamic pressure surface, and it is likely to leak outward from the outer peripheral side opening of the inclined bearing space by the rotational centrifugal force. The lubricant fluid is stably held in the inclined bearing space, and the fluid pressurizing means favorably assists the lubricating fluid holding function of the fluid seal portion.
[0010]
In the conical dynamic pressure bearing device according to claim 2 of the present invention, the fluid pressurizing means according to claim 1 is formed of a number of concave grooves arranged in an annular shape.
According to the conical dynamic pressure bearing device according to claim 2 having such a configuration, the fluid pressurizing means having a simple pressurizing function with a simple configuration is efficiently manufactured.
[0011]
Further, in the conical dynamic pressure bearing device according to claim 3 of the present invention, the fluid pressurizing means in claim 1 is provided on at least one side of both opposing wall surfaces in the radial direction of the bearing sleeve and the shaft bush. In the conical hydrodynamic bearing device according to claim 4 of the present invention, the fluid pressurizing means according to claim 1 is provided on at least one side of both opposing wall surfaces in the axial direction of the bearing sleeve and the shaft bush. It has been.
According to the conical hydrodynamic bearing device according to claim 3 or claim 4 having such a configuration, the fluid pressurizing means having a good pressurizing function utilizes the opposing wall surface of the bearing sleeve or the shaft bush. It is easy to manufacture.
[0012]
On the other hand, in the conical hydrodynamic bearing device according to claim 5 of the present invention, the lubricating fluid that has flowed out of the inclined bearing space is guided to the bearing sleeve of claim 1 so as to return to the inner side of the inclined bearing space. A circulation hole is provided, and one end side opening of the circulation hole is disposed between the inclined bearing space and the fluid pressurizing means.
According to the conical dynamic pressure bearing device of the fifth aspect having such a configuration, the lubricating fluid is smoothly moved through the circulation hole by the pressurizing action of the fluid pressurizing means.
[0013]
On the other hand, in a recording disk drive device according to a sixth aspect of the present invention, the spindle motor having the conical dynamic pressure bearing device according to any one of the first to fifth aspects and a rotor of the spindle motor are mounted. And a recording head for recording or reproducing information on the information recording disk.
According to the recording disk drive apparatus according to the sixth aspect having such a configuration, the above-described good operation can be achieved also in the recording disk drive apparatus.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. Prior to this, a spindle motor for a hard disk drive (HDD) having a conical (conical) hydrodynamic bearing device to which the present invention is applied will be described. The outline of will be explained.
[0015]
The entire shaft rotation / outer rotor type spindle motor shown in FIG. 1 includes a stator assembly 10 as a fixed member and a rotor assembly as a rotation member assembled from the upper side of the stator assembly 10 in the figure. 20 is included.
[0016]
The stator assembly 10 has a base frame 11 that is screwed to a main body plate of a hard disk drive (HDD) (not shown). On the inner peripheral side of a cylindrical sleeve holding portion (bearing member holder) 12 formed in the substantially central portion of the base frame 11, a hollow bearing sleeve 13 is fixed by fixing means such as press fitting or shrink fitting. The base frame 11 is integrally joined. The bearing sleeve 13 is made of a copper-based material such as phosphor bronze in order to facilitate the processing, and has a substantially conical bearing center hole 13a having openings at both ends in the axial direction. Further, on the outer peripheral surface of the sleeve holding portion 12, a stator core portion 15 in which a stator coil 14 is wound around a salient pole portion of a stator core projecting radially is fitted.
[0017]
Further, a shaft bush 21 as a shaft member constituting a part of the rotor set 20 is inserted into the bearing center hole 13a of the bearing sleeve 13 so as to be rotatable around the rotation center axis X. ing. The shaft bush 21 in the present embodiment is formed of stainless steel having a substantially conical shape corresponding to the bearing center hole 13a of the bearing sleeve 13 described above. A substantially conical inclined dynamic pressure surface is formed on the inner peripheral surface of the bearing center hole 13a in the bearing sleeve 13, and a substantially conical inclined dynamic motion is also formed on the outer peripheral surface of the shaft bush 21. Each pressure surface is formed. In addition, on the inclined dynamic pressure surface of the bearing sleeve 13, an annular recess as an oil reservoir is recessed so as to form a belt shape at a substantially central portion.
[0018]
Further, an inclined bearing space BS composed of a minute gap is formed at the opposing portion between the two inclined dynamic pressure surfaces, and the two conical dynamic pressure bearing portions CB and CB are axially arranged in the inclined bearing space BS. Are formed at an appropriate interval. More specifically, the inclined dynamic pressure surface on the bearing sleeve 13 side and the inclined dynamic pressure surface on the shaft bush 21 side constituting the respective conical dynamic pressure bearing portions CB form an inclined bearing space having a gap of several μm. The bearing space BS including the inclined bearing space is continuously filled with a lubricating fluid such as an ester-based or poly-α-olefin-based lubricating oil.
[0019]
At this time, the opening provided at the lower end of the bearing sleeve 13 is closed by the cover 13b, and the cover 13b prevents the lubricating fluid in each of the conical hydrodynamic bearings from leaking to the outside. ing.
[0020]
Further, on at least one side of the both inclined dynamic pressure surfaces of the bearing sleeve 13 and the shaft bush 21, dynamic pressure generating means having a herringbone-shaped concave groove structure (not shown) is divided into two blocks in the axial direction. When the shaft bush 21 is rotationally driven, the lubricating fluid is pressurized by the pumping action of each of the dynamic pressure generating grooves to generate a dynamic pressure. The dynamic pressure of the lubricating fluid causes the shaft to rotate. The bush 21 is lifted relative to the bearing sleeve 13 in the radial direction and the thrust direction, and is held in a non-contact state. Thus, the shaft bush 21 and the shaft bush 21 are integrally formed or fixed integrally. The rotating hub body 22 is configured to be rotatably supported.
[0021]
The lubricating fluid pressurized by the dynamic pressure generating grooves in this way flows out from the end openings at both end portions in the axial direction of the inclined bearing space BS including the conical dynamic pressure bearing portions CB. However, the lubricating fluid that has flowed to the outside returns to the original conical dynamic pressure bearing portion CB through the circulation hole 13c provided so as to penetrate the body portion of the bearing sleeve 13 in an inclined state. It is made the composition which is. That is, the opening on the lower end side of the circulation hole 13c is opened in the internal space of the cover 13b, and the opening on the upper end side is the upper end surface of the bearing sleeve 13, that is, the inclined bearing space BS. And a fluid pressurizing means 13e to be described later.
[0022]
On the other hand, the rotating hub body 22 constituting the rotor set 20 together with the shaft bush 21 is formed in a substantially cup shape so that various information recording medium disks such as a magnetic disk can be mounted. 21 and an integral member.
[0023]
The rotating hub body 22 has an annular body 22a for forming a rotor portion on the outer periphery thereof, and NS alternately on the inner peripheral surface side of the annular body 22a at regular intervals in the circumferential direction. A magnetized cylindrical rotor magnet 22b is mounted and fixed, thereby forming a rotor portion. The rotor magnet 22b is disposed close to the outer circumferential surface of the stator core portion 15 so as to face the ring.
[0024]
The lower end surface in the axial direction of the rotor magnet 22b is in a positional relationship facing the magnetic attraction plate 16 attached on the base frame 11 side in the axial direction, and between the two members 22b and 16 The entire rotating hub body 22 described above is attracted in the axial direction by the magnetic attractive force, and a stable rotational state is obtained.
[0025]
Furthermore, as shown in FIG. 2 in particular, the upper end surface of the bearing sleeve 13 shown in the drawing and the rotating hub 22 extending to the outer peripheral side of the large-diameter portion on the base side of the shaft bush 21 described above. The tilted bearing space BS described above is disposed between the illustrated upper end surface of the bearing sleeve 13 and the illustrated lower end surface of the rotating hub 22. Is formed so as to extend along the radial direction substantially orthogonal to the rotation axis X described above. In addition, a radial clearance RS that is bent substantially at a right angle downward in the drawing and extends in the axial direction is formed in the end opening on the outer peripheral side of the axial facing clearance AS.
[0026]
The radial clearance RS includes an outer peripheral surface of a retaining latch 13d projecting so as to form a flange at the outermost circumferential portion of the upper end portion of the bearing sleeve 13 and the retaining latch 13d. Is formed by bringing the lower end surface of the center side of the rotating hub 22 close to the inner peripheral surface of the annular central base portion 22c protruding substantially downward in the radial direction so as to cover the outer peripheral side from the outer peripheral side. Has been. A composite fluid seal portion CS using both capillary force and rotational centrifugal force is connected to the end opening on the lower end side of the radial gap RS in the drawing so as to extend downward in the drawing. ing.
[0027]
An inner peripheral side inclined wall surface and an outer peripheral side inclined wall surface of the composite fluid seal part CS are the outer peripheral side surface of the bearing sleeve 13 and the retaining member arranged to face the bearing sleeve 13 radially outward. Are formed by the inner peripheral surface of the annular body member 25. The annular body member 25 is formed of an annular member formed in a substantially ring shape, and the plate-shaped hub mounting portion 25a forming the outer peripheral side portion of the annular body member 25 is the above-described rotating hub. It is fixed by a fixing portion 22 d provided on 22.
[0028]
Further, as described above, the upper end portion of the bearing sleeve 13 shown in the drawing is provided with the retaining locking collar portion 13d protruding so as to project outward in the radial direction. A part of 13d is disposed so as to face the upper surface side of the main body portion 25b of the annular body member 25 described above in the axial direction. The two members 13d and 25b are arranged so as to be able to contact in the axial direction, thereby preventing the rotating hub 22 from coming out in the axial direction. In other words, the hub mounting portion 25a of the annular body member 25 described above is disposed on the radially outward side of the retaining locking collar portion 13d provided on the bearing sleeve 13, and the retaining locking collar portion described above. The inner peripheral wall surface of the hub mounting portion 25a of the annular body member 25 is disposed so as to face the outer peripheral wall surface of 13d from the radially outer side.
[0029]
Further, as described above, the composite fluid seal portion CS is formed in the end opening located on the outer peripheral side of the inclined bearing space BS so as to be continuous via the axial facing gap AS and the radial gap RS, The inside of the continuous space is filled with the lubricating fluid in the inclined bearing space BS to be continuous. At this time, as shown in FIG. A fluid pressurizing means 13e is formed on the outer peripheral surface of the retaining locking collar portion 13d of the formed bearing sleeve 13 so as to pressurize the above-described lubricating fluid in the direction of pushing in toward the inner side of the inclined bearing space BS. Yes.
[0030]
The fluid pressurizing means 13e in the present embodiment is formed by a large number of spiral concave grooves arranged in an annular shape, and externally leaks lubricating fluid in the inclined bearing space BS and the inclined bearing space BS. It arrange | positions in the part between the fluid seal | sticker parts CS to prevent. Then, the fluid pressurizing means 13e pressurizes the lubricating fluid toward the upper side in the drawing as indicated by an arrow V in FIG. 2, and pumps the lubricating fluid into the inclined bearing space BS described above. It is made the structure which pressurizes to the side.
[0031]
At this time, the flow direction of the lubricating fluid in the inclined bearing space BS is set to the lower side in the drawing in the present embodiment, but may be set to the upper side in the drawing as shown in FIG. It is.
[0032]
As described above, in the present embodiment, the lubricating fluid pressurized by the fluid pressurizing means 13e is pushed from the outer peripheral side to the inner side of the inclined bearing space BS, thereby affecting the opening angle of the inclined dynamic pressure surface. Therefore, the dynamic pressure is generated satisfactorily in the lubricating fluid in the inclined bearing space BS.
[0033]
Further, the lubricating fluid which is about to leak outward from the outer peripheral side opening of the inclined bearing space BS by the rotational centrifugal force is directed toward the inclined bearing space BS as indicated by an arrow W in FIG. It is pushed in and is held stably. That is, in the present embodiment, since the fluid pressurizing means 13e is disposed between the inclined bearing space BS and the fluid seal portion CS, the fluid pressurizing means 13e holds the lubricating fluid in the fluid seal portion CS. The function is well assisted.
[0034]
Furthermore, since the fluid pressurizing means 13e in the present embodiment is formed from a large number of spiral concave grooves arranged in an annular shape, the fluid pressurizing means 13e having a good pressurizing function with a simple configuration can be obtained. It is designed to be manufactured efficiently.
[0035]
Next, in the embodiment according to FIG. 5, the fluid pressurizing means 13 f is provided on the inner peripheral surface of the annular central base portion 22 c of the rotary hub 22 that forms the aforementioned radial clearance RS. The fluid pressurizing means 13f is formed of a large number of spiral-shaped concave grooves arranged in an annular shape so as to pressurize the lubricating fluid in the direction in which the lubricating fluid is pushed toward the inner side of the inclined bearing space BS. The structure is configured such that the pressure is applied toward the upper side in the figure, and the pressure-in action of the pump-in is performed on the inclined bearing space BS described above. Also in such an embodiment, the same operation and effect as the above-described embodiment can be achieved.
[0036]
On the other hand, in the embodiment shown in FIG. 6, the lubricating fluid is applied to the upper end surface in the drawing of the retaining locking collar portion 13 d of the bearing sleeve 13, that is, the end surface forming the above-described axially facing gap AS. A fluid pressurizing means 13g is formed to pressurize in the direction toward the inside of the inclined bearing space BS. The fluid pressurizing means 13g in the present embodiment is also formed from a large number of spiral-shaped concave grooves arranged in an annular shape, pressurizing the lubricating fluid toward the center side, and with respect to the inclined bearing space BS described above. The pump-in is configured to perform a pressurizing action.
[0037]
Even in such an embodiment, the same operation and effect as in the above-described embodiment can be obtained, but the above-described fluid pressurizing means 13g is formed on the rotary hub 22 side forming the axially opposed gap AS. It is also possible to do.
[0038]
Next, in the embodiment shown in FIG. 7 in which the same reference numerals are given to the components corresponding to the hard disk drive device (HDD) according to FIG. In addition, an annular retaining ring 21a is fixed. The retaining ring 21a is disposed in a storage portion 13h that is recessed in the center portion of the bearing sleeve 13 on the lower end side in the figure, and has a function of preventing the rotor set 20 from being detached by such an arrangement relationship. Yes. Also in such an embodiment, it is possible to adopt the same configuration as the fluid pressurizing means 13e, 13f, and 13g described above, and the same operations and effects as those can be obtained.
[0039]
In addition, the spindle motor in each of the embodiments is used by being mounted inside a hard disk drive (HDD) as shown in FIG. 8, for example. That is, as shown in FIG. 8, the spindle motor M including the conical dynamic pressure bearing device according to each of the above-described embodiments is fixed to the main body plate 100 a constituting the hermetic housing 100. The internal space of the housing 100 including the spindle motor M is formed in the clean space 100c by the sealing lid 100b fitted to the main body plate 100a. An information recording disk 101 such as a hard disk is mounted on the rotating hub (see reference numeral 22 in FIG. 1) of the spindle motor M, and the clamp 103 fixed to the rotating hub with a screw 102 is used to The information recording disk 101 is held in an immobile state.
[0040]
As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.
[0041]
For example, in each of the embodiments described above, the bearing sleeve 13 is provided with the circulation hole 13c for the lubricating fluid. However, the present invention can be similarly applied to an apparatus having no such circulation hole.
[0042]
In each of the above-described embodiments, the present invention is applied to a spindle motor for a hard disk drive (HDD). However, the present invention is applicable to various other conical dynamic bearing devices. The same can be applied.
[0043]
【The invention's effect】
As described above, the conical hydrodynamic bearing device according to claim 1 of the present invention includes the substantially conical inclined bearing space formed in the opposing gap between the inclined dynamic pressure surfaces of the bearing sleeve and the shaft bush, and the inclination thereof. A fluid pressurizing unit that pressurizes the lubricating fluid in the direction of pushing in toward the inner side of the inclined bearing space is provided between the fluid seal portion that prevents external leakage of the lubricating fluid in the bearing space, and is applied by the fluid pressurizing unit. The compressed lubricating fluid is pushed from the outer peripheral side to the inner side of the inclined bearing space to generate a good dynamic pressure in the lubricating fluid in the inclined bearing space regardless of the opening angle of the inclined dynamic pressure surface. Since the lubricating fluid that is about to leak out from the outer peripheral side opening of the inclined bearing space is stably held in the inclined bearing space, the opening angle of the inclined dynamic pressure surface is increased. As a result, it is possible to stably and surely obtain a good relative flying height, and to well prevent the lubricating fluid leakage from the inclined bearing space and to assist the lubricating fluid holding function of the fluid seal portion well. The reliability of the conical type (conical type) hydrodynamic bearing device can be improved while reducing the size.
[0044]
According to a second aspect of the present invention, there is provided a conical type hydrodynamic bearing device, wherein the fluid pressurizing means according to the first aspect is formed from a plurality of concave grooves arranged in an annular shape, and has a good pressurizing function with a simple configuration. Therefore, in addition to the above-described effects, productivity can be improved.
[0045]
Furthermore, the conical type dynamic pressure bearing device according to claim 3 of the present invention is characterized in that the fluid pressurizing means in claim 1 is provided on at least one side of both opposing wall surfaces in the radial direction of the bearing sleeve and the shaft bush. According to a fourth aspect of the present invention, there is provided a conical hydrodynamic bearing device according to the first aspect, wherein the fluid pressurizing means according to the first aspect is provided on at least one side of both opposing wall surfaces in the axial direction of the bearing sleeve and the shaft bush. In addition, since the fluid pressurizing means having a good pressurizing function is configured to be easily manufactured using the opposing wall surface of the bearing sleeve or the shaft bush, the above-described effects can be further improved and the production can be performed. Can increase the sex.
[0046]
A conical hydrodynamic bearing device according to claim 5 of the present invention guides the bearing sleeve in claim 1 so that the lubricating fluid that has flowed out to the outside of the inclined bearing space is returned to the inside of the inclined bearing space. Since the circulation hole is provided so that the lubricating fluid can be smoothly moved by the pressurizing action of the fluid pressurizing means through the circulation hole, the above-described effects can be further enhanced.
[0047]
On the other hand, a recording disk drive device according to a sixth aspect of the present invention is an information recording disk mounted on a rotor of a spindle motor provided with the conical dynamic pressure bearing device according to any one of the first to fifth aspects. Since the information is recorded or reproduced by the recording head, the above-described effects can be obtained also in the disk recording apparatus.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional explanatory view showing an outline of a shaft rotation type HDD spindle motor provided with a conical dynamic pressure bearing device according to an embodiment of the present invention.
FIG. 2 is an explanatory longitudinal sectional view showing an enlarged structure of a conical dynamic pressure bearing portion used in the HDD spindle motor shown in FIG. 1;
3 is an enlarged side view illustrating a bearing sleeve of a conical dynamic pressure bearing portion used in the HDD spindle motor shown in FIG. 1. FIG.
4 is an explanatory longitudinal sectional view showing another structure of a conical dynamic pressure bearing portion used in the HDD spindle motor shown in FIG. 1 in an enlarged manner. FIG.
FIG. 5 is a longitudinal sectional explanatory view showing a rotary member including a shaft bush of a shaft rotation type HDD spindle motor provided with a conical dynamic pressure bearing device according to another embodiment of the present invention.
FIG. 6 is an explanatory plan view showing another embodiment of the bearing sleeve of the conical dynamic pressure bearing portion.
FIG. 7 is a longitudinal cross-sectional explanatory view showing an outline of a shaft rotation type HDD spindle motor provided with a conical dynamic pressure bearing device in still another embodiment of the present invention.
FIG. 8 is a longitudinal sectional explanatory view showing a schematic structure example of a recording disk drive device using a spindle motor provided with a conical dynamic pressure bearing device according to the present invention.
[Explanation of symbols]
13 Bearing sleeve 13a Bearing center hole 13b Cover 13c Circulation hole 13d Detent locking hooks 13e, 13f, 13g Fluid pressurizing means 14 Stator coil 15 Stator core 16 Magnetic suction plate 21 Shaft bush 22 Rotating hub body 22b Rotor magnet 22c Annular center base 25 Annular body member BS Inclined bearing space CB Conical dynamic pressure bearing part AS Axial facing gap RS Radial gap CS Fluid seal part X Rotation center axis

Claims (6)

A shaft bush having the substantially conical inclined dynamic pressure surface on the outer peripheral surface is inserted into the bearing sleeve having the substantially conical inclined dynamic pressure surface on the inner peripheral surface so as to be relatively rotatable.
A substantially conical inclined bearing space is formed in the opposing gap between the inclined dynamic pressure surfaces of the bearing sleeve and the shaft bush,
The inclined bearing space is filled with a lubricating fluid, and appropriate dynamic pressure generating means is formed on at least one side of both inclined dynamic pressure surfaces of the shaft bush and the bearing sleeve,
The dynamic pressure generating means pressurizes the lubricating fluid to generate a dynamic pressure, and the dynamic pressure of the lubricating fluid is used to lift the shaft bush and the bearing sleeve while relatively floating in the radial direction and the thrust direction. In the conical dynamic pressure bearing device configured to be rotationally supported by contact,
The tilt bearing space is provided with a fluid seal portion that prevents external leakage of the lubricating fluid in the tilt bearing space, and
A conical dynamic pressure is provided between the inclined bearing space and the fluid seal portion, wherein fluid pressurizing means is provided to pressurize the lubricating fluid in a direction of pushing the lubricating fluid toward the inner side of the inclined bearing space. Bearing device. 2. The conical hydrodynamic bearing device according to claim 1, wherein the fluid pressurizing means is formed of a plurality of concave grooves arranged in an annular shape. 2. The conical hydrodynamic bearing device according to claim 1, wherein the fluid pressurizing means is provided on at least one side of both opposing wall surfaces in the radial direction of the bearing sleeve and the shaft bush. The conical hydrodynamic bearing device according to claim 1, wherein the fluid pressurizing means is provided on at least one side of both opposing wall surfaces in the axial direction of the bearing sleeve and the shaft bush. The bearing sleeve is provided with a circulation hole for guiding the lubricating fluid that has flowed out to the outside of the inclined bearing space so as to return it to the inner side of the inclined bearing space,
The conical type dynamic pressure bearing device according to claim 1, wherein the opening on one end side of the circulation hole is disposed between the inclined bearing space and the fluid pressurizing means. A spindle motor comprising the conical dynamic pressure bearing device according to any one of claims 1 to 5, an information recording disk mounted on a rotor of the spindle motor, and information is recorded on the information recording disk, Or a recording disk drive having a recording head for reproduction.

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