JP2004176816A - Dynamic pressure bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the distribution of extra adhesive when an adhesive is used as a means for fixing a bearing sleeve to a housing. <P>SOLUTION: A recessed adhesive agent sump U is formed in the inner peripheral surface 7c of the housing 7. The adhesive agent sump U is formed in the inner peripheral surface 7c of the housing 7 in a circumferential groove shape, and its both side areas in the axial direction are formed of tapered surfaces U1. Since the adhesive agent sump U is provided in the inner peripheral surface 7c of the housing 7, even when the extra amount of the adhesive agent T is produced depending upon a coated amount, its extra adhesive agent is caught by the recessed adhesive agent sump U, and the distribution of the adhesive agent T which affects the positioning of the bearing sleeve 8 and affecting a bearing performance is prevented. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dynamic bearing device that rotatably supports a shaft member in a non-contact manner by a dynamic pressure action of lubricating oil generated in a bearing gap. This bearing device is a spindle for information equipment, for example, a magnetic disk device such as an HDD or FDD, an optical disk device such as a CD-ROM, a CD-R / RW, a DVD-ROM / RAM, or a magneto-optical disk device such as an MD or MO. It is suitable for a motor, a polygon scanner motor of a laser beam printer (LBP), or a small motor such as an electric device such as an axial fan.
[0002]
[Prior art]
The above various motors are required to have high speed, low cost, low noise, etc. in addition to high rotational accuracy. One of the components that determine these required performances is a bearing that supports the spindle of the motor, and in recent years, as this type of bearing, the use of a dynamic pressure bearing having characteristics excellent in the required performance has been studied. Or it is actually used.
[0003]
For example, in a hydrodynamic bearing device incorporated in a spindle motor of a disk drive device such as an HDD, a radial bearing portion that rotatably supports a shaft member in a radial direction in a non-contact manner, and a non-contact support rotatably supports a shaft member in a thrust direction. A thrust bearing portion is provided, and as the radial bearing portion, a dynamic pressure bearing in which a groove (dynamic pressure groove) for generating dynamic pressure is provided on the inner peripheral surface of the bearing sleeve or the outer peripheral surface of the shaft member is used. As the thrust bearing portion, for example, a dynamic pressure groove provided on both end surfaces of a flange portion of a shaft member or a surface opposed thereto (an end surface of a bearing sleeve, an end surface of a thrust member fixed to a housing, or the like). A pressure bearing is used (for example, see Patent Document 1).
[0004]
Usually, the bearing sleeve is fixed at a predetermined position on the inner periphery of the housing, and a seal portion is often provided at the opening of the housing to prevent the lubricating oil injected into the internal space of the housing from leaking outside. .
[0005]
[Patent Document 1]
JP-A-2002-061641
[Problems to be solved by the invention]
In such a dynamic pressure bearing device, an adhesive may be used as a means for fixing the bearing sleeve to the housing. In this case, for example, an adhesive is applied in advance to the inner peripheral surface of the housing, and the bearing sleeve is inserted into the inner peripheral surface of the housing to be positioned at a predetermined position, and then the adhesive is solidified. However, depending on the amount of the adhesive applied, when the bearing sleeve is inserted into the inner peripheral surface of the housing and moved to a predetermined position, an excess amount of the adhesive wraps around to the front in the moving direction of the bearing sleeve, and the positioning of the bearing sleeve is performed. And undesired effects on bearing performance.
[0007]
For example, in the dynamic pressure bearing device described in Patent Document 1, the end surface of one end of the bearing sleeve is brought into contact with the inner surface of a seal portion (flange portion) provided at one end of the housing, so that the housing of the bearing sleeve is provided. However, if the surplus adhesive wraps around, when the bearing sleeve is moved to the final position, the adhesive enters between the one end surface of the bearing sleeve and the inner surface of the seal, and The position of the sleeve with respect to the housing may not be determined with high accuracy.
[0008]
In addition, the present applicant has formed a vertical groove on the outer peripheral surface of the bearing sleeve, and formed a horizontal groove on the one end side of the bearing sleeve to communicate the vertical groove with the inner peripheral surface of the bearing sleeve. An application has already been filed for a hydrodynamic bearing device that forms a circulation path for a lubricating fluid filled in a space (Japanese Patent Application No. 2002-117297). In this hydrodynamic bearing device, there is a possibility that the lateral groove may be closed by the adhesive due to the surplus adhesive flowing around.
[0009]
An object of the present invention is to prevent surplus adhesive from wrapping around and to avoid the influence of surplus adhesive wrapping around.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a housing, a bearing sleeve fixed to an inner peripheral surface of the housing with an adhesive, a shaft member, and a shaft member, provided between the bearing sleeve and the shaft member. In a hydrodynamic bearing device provided with a radial bearing portion for supporting a shaft member in a non-contact manner in a radial direction by a dynamic pressure action of generated lubricating oil, a concave adhesive is provided between an inner peripheral surface of a housing and an outer peripheral surface of a bearing sleeve. An arrangement having a reservoir is provided.
[0011]
According to the above configuration, even when an excess amount of the adhesive occurs due to the applied amount, the excess adhesive is captured by the concave adhesive pool, and the adhesive wraps around the bearing, which adversely affects the positioning of the bearing sleeve and the bearing performance. Is prevented.
[0012]
The above-mentioned adhesive reservoir can be formed on the inner peripheral surface of the housing or the outer peripheral surface of the bearing sleeve. Alternatively, concave portions may be formed on both the inner peripheral surface of the housing and the outer peripheral surface of the bearing sleeve so as to face each other, and the concave space formed by the both may be used as the adhesive reservoir. Preferably, the adhesive reservoir is formed on the inner peripheral surface of the housing. The adhesive may be provided at a plurality of locations.
[0013]
The shape of the above-mentioned adhesive reservoir is not particularly limited, but it is preferable that the shape is gradually reduced toward both sides in the axial direction. When the bearing sleeve is inserted into the inner peripheral surface of the housing, an excess amount of the adhesive may be trapped in the adhesive pool, but even in such a case, after the positioning of the bearing sleeve, the adhesive may be removed. Until the solidification occurs, the excess adhesive trapped in the adhesive pool flows to both sides in the axial direction, which has been narrowed by capillary action, and the original fixing portion (the outer peripheral surface of the bearing sleeve and the inner peripheral surface of the housing) And the filling gap between them). For this reason, there is no excess or deficiency in the amount of the adhesive at the fixing portion, and a stable fixing state can be obtained.
[0014]
Further, the present invention provides a housing, a bearing sleeve fixed to an inner peripheral surface of the housing, a shaft member having a shaft portion and a flange portion, a seal portion provided at one end of the housing, and another end portion of the housing. A radial bearing portion, which is provided between the bearing sleeve and the shaft portion and is provided between the bearing sleeve and the shaft portion to support the shaft portion in a non-contact manner in the radial direction by the dynamic pressure action of the lubricating oil generated in the radial bearing gap; A thrust bearing portion provided between the thrust portion and the flange portion for supporting the flange portion in a non-contact manner in the thrust direction by a dynamic pressure action of lubricating oil generated in a thrust bearing gap, and the lubricating fluid is filled in the internal space of the housing. In the hydrodynamic bearing device described above, the inner surface of the seal portion partially contacts the inner diameter region of the one end surface of the bearing sleeve at the inner diameter region, and the outer diameter region thereof Providing a structure that forms a grinding undercut portion away from the one end face of the sleeve.
[0015]
According to the above configuration, the lubricating fluid filled in the internal space of the housing can flow and circulate in the internal space, whereby the pressure of the lubricating oil in the internal space locally becomes negative. Thus, problems such as generation of air bubbles due to the generation of negative pressure, leakage of lubricating oil and generation of vibration due to generation of air bubbles can be solved.
[0016]
In addition, when the bearing sleeve is fixed to the inner peripheral surface of the housing with an adhesive, even if the adhesive wraps around, the outer peripheral side area of the inner surface of the seal portion and the one end side end surface of the bearing sleeve. Since there is a slim part having a required space volume, the adhesive hardly flows in the direction of the radial groove. Thereby, the situation where the radial groove is closed by the adhesive can be avoided.
[0017]
In the above configuration, the bearing sleeve can be formed of a sintered metal.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0019]
FIG. 1 shows an example of a configuration of a spindle motor for information equipment incorporating a hydrodynamic bearing device 1 according to this embodiment. The spindle motor is used in a disk drive device such as an HDD, and includes a hydrodynamic bearing device 1 that rotatably supports a shaft member 2 in a non-contact manner, a rotor (disk hub) 3 mounted on the shaft member 2, For example, a stator 4 and a rotor magnet 5 are provided facing each other via a radial gap. The stator 4 is attached to the outer periphery of the bracket 6, and the rotor magnet 5 is attached to the inner periphery of the disk hub 3. The housing 7 of the hydrodynamic bearing device 1 is mounted on the inner periphery of the bracket 6. The disk hub 3 holds one or more disks D such as magnetic disks. When the stator 4 is energized, the rotor magnet 5 rotates by the electromagnetic force between the stator 4 and the rotor magnet 5, whereby the disk hub 3 and the shaft member 2 rotate integrally.
[0020]
FIG. 2 shows the dynamic pressure bearing device 1. The hydrodynamic bearing device 1 includes a housing 7, a bearing sleeve 8 and a thrust member 10 fixed to the housing 7, and a shaft member 2.
[0021]
A first radial bearing portion R1 and a second radial bearing portion R2 are provided between the inner peripheral surface 8a of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a of the shaft member 2 so as to be separated in the axial direction. Further, a first thrust bearing portion S1 is provided between a lower end surface 8c of the bearing sleeve 8 and an upper end surface 2b1 of the flange portion 2b of the shaft member 2, and an end surface 10a of the thrust member 10 and a lower end surface of the flange portion 2b. The second thrust bearing portion S2 is provided between the second thrust bearing portion S2 and the second thrust bearing portion S2. For the sake of convenience, the description will be made with the side of the thrust member 10 being the lower side and the side opposite to the thrust member 10 being the upper side.
[0022]
The housing 7 is made of, for example, a soft metal material such as brass or a resin material such as a thermoplastic resin, and has a cylindrical side portion 7b and an annular seal portion 7a integrally extending from the upper end of the side portion 7b to the inner diameter side. And An inner peripheral surface 7a1 of the seal portion 7a faces a tapered surface 2a2 provided on an outer periphery of the shaft portion 2a via a predetermined seal space S. The tapered surface 2a2 of the shaft portion 2a gradually decreases in diameter toward the upper side (outside of the housing 7), and also functions as a centrifugal force seal by the rotation of the shaft member 2.
[0023]
The shaft member 2 is formed of, for example, a metal material such as stainless steel, and includes a shaft portion 2a and a flange portion 2b provided integrally or separately at a lower end of the shaft portion 2a.
[0024]
The bearing sleeve 8 is formed of, for example, a porous body made of a sintered metal, particularly a porous body of a sintered metal containing copper as a main component, and is formed in a cylindrical shape, and is fixed at a predetermined position on an inner peripheral surface 7c of the housing 7. .
[0025]
On the inner peripheral surface 8a of the bearing sleeve 8 formed of this sintered metal, two upper and lower regions serving as radial bearing surfaces of a first radial bearing portion R1 and a second radial bearing portion R2 are provided axially separated. In these two regions, for example, herringbone-shaped dynamic pressure grooves 8a1 and 8a2 as shown in FIG. The upper dynamic pressure groove 8a1 is formed asymmetrically in the axial direction with respect to the axial center m (the axial center of the region between the upper and lower inclined grooves), and the axial dimension X1 of the upper region is lower than the axial center m. It is larger than the axial dimension X2 of the side region. One or more axial grooves 8d1 are formed on the outer peripheral surface 8d of the bearing sleeve 8 over the entire length in the axial direction. In this example, three axial grooves 8d1 are formed at equal circumferential intervals. Further, chamfers 8e and 8f are formed at the outer peripheral corners of the upper end face 8b and the lower end face 8c, respectively.
[0026]
For example, a spiral dynamic pressure groove 8c1 as shown in FIG. 3B is formed on the lower end surface 8c of the bearing sleeve 8, which is the thrust bearing surface of the first thrust bearing portion S1. The shape of the dynamic pressure groove may be a herringbone shape, a radial groove shape, or the like.
[0027]
As shown in FIG. 3C, the upper end surface 8b of the bearing sleeve 8 is divided into an inner diameter side region 8b2 and an outer diameter side region 8b3 by a V-shaped cross-sectional circumferential groove 8b1 provided at a substantially central portion in the radial direction. One or more radial grooves 8b21 are formed in the divided inner diameter side region 8b2. In this example, three radial grooves 8b21 are formed at equal circumferential intervals.
[0028]
As shown in FIG. 2, in this embodiment, a concave adhesive reservoir U is formed on the inner peripheral surface 7c of the housing 7. The adhesive reservoir U is formed, for example, in the shape of a circumferential groove on the inner peripheral surface 7c of the housing 7, and both axial regions are each formed of a tapered surface U1. Therefore, the adhesive reservoir U has a shape gradually reduced toward both sides in the axial direction.
[0029]
Further, the inner surface 7a2 of the seal portion 7a partially contacts the inner diameter region 8b2 of the upper end surface 8b of the bearing sleeve 8 at its inner diameter region 7a21, and the outer diameter region 7a22 thereof contacts the upper end surface of the bearing sleeve 8. 8b is formed in a slanted or curved shape so as to be separated from 8b. Therefore, a slim part P having a required space volume is formed between the outer diameter side region 7a22 of the inner side surface 7a2 and the upper end surface 8b (including the chamfer 8e). The inner diameter side of the slim part P communicates with the circumferential groove 8b1, and the outer diameter side has a tapered space formed between the slim part P and the chamfer 8e.
[0030]
The thrust member 10 is formed of, for example, a metal material such as brass, and is fixed to a lower end portion of the inner peripheral surface 7c of the housing 7. As shown in FIG. 4, for example, a herringbone-shaped dynamic pressure groove 10a1 is formed on an end face 10a of the thrust member 10, which serves as a thrust bearing surface of the second thrust bearing portion S2. The dynamic pressure groove may have a spiral shape, a radial groove shape, or the like.
[0031]
The hydrodynamic bearing device 1 of this embodiment is assembled in the following steps, for example.
[0032]
First, a predetermined amount of an adhesive is applied to the inner peripheral surface 7c of the housing 7. Then, the bearing sleeve 8 is inserted into the inner peripheral surface 7c of the housing 7, and its upper end surface 8b is brought into contact with the inner surface 7a2 of the seal portion 7a. Thereby, the bearing sleeve 8 is positioned with respect to the housing 7. When the adhesive is solidified while maintaining this state, the bearing sleeve 8 is fixed while being positioned with respect to the housing 7.
[0033]
In this embodiment, since the adhesive pool U is provided on the inner peripheral surface 7c of the housing 7, even if the adhesive T (see the enlarged view in the circle in FIG. 2) is generated due to the applied amount, the amount of the adhesive T is reduced. Excess adhesive is trapped by the concave adhesive reservoir U, so that the adhesive T, which adversely affects the positioning of the bearing sleeve 8 and the bearing performance, is prevented. Further, the adhesive reservoir U has a shape gradually reduced toward both sides in the axial direction due to the tapered surface U1, so that after the positioning of the bearing sleeve 8, the adhesive T is solidified until the adhesive T is solidified. The excessively trapped adhesive T flows to both sides in the axial direction narrowed by the capillary action, and is originally fixed (the filling gap between the outer peripheral surface 8d of the bearing sleeve 8 and the inner peripheral surface 7c of the housing 7). Is filled. Therefore, the amount of the adhesive at the fixing portion of the bearing sleeve 8 is not excessive or insufficient, and a stable fixing state can be obtained.
[0034]
Further, since a slim part P having a required space volume is formed between the outer diameter side region 7a22 of the inner side surface 7a2 of the seal part 7a and the upper end surface 8b (including the chamfer 8e) of the bearing sleeve 8, Even if the adhesive wraps around, it becomes difficult for the adhesive T to flow in the direction of the radial groove 8b21. In particular, in this embodiment, there is a tapered space (formed between the chamfer 8e) on the outer diameter side of the threaded portion P, and the adhesive T in the threaded portion P is fixed by the capillary action of the tapered space. Since it is drawn in the direction of the portion (the filling gap between the outer peripheral surface 8d of the bearing sleeve 8 and the inner peripheral surface 7c of the housing 7), the flow in the direction of the radial groove 8b21 is more effectively prevented. This avoids the situation where the radial groove 8b21 is closed by the adhesive T.
[0035]
Next, the shaft member 2 is mounted on the bearing sleeve 8. Note that the inner diameter of the bearing sleeve 8 is measured in a state where the bearing sleeve 8 is fixed to the housing 7, and dimension matching with the outer diameter of the shaft portion 2a (measured in advance) is performed to reduce the radial bearing gap. It can be set with high accuracy.
[0036]
After that, the thrust member 10 is mounted on the lower end of the inner peripheral surface 7c of the housing 7, positioned at a predetermined position, and fixed by an appropriate means such as an adhesive.
[0037]
When assembly is completed as described above, the shaft portion 2a of the shaft member 2 is inserted into the inner peripheral surface 8a of the bearing sleeve 8, and the flange portion 2b is connected to the lower end surface 8c of the bearing sleeve 8 and the end surface 10a of the thrust member 10. In the space between them. Thereafter, the internal space of the housing 7 sealed with the seal portion 7a is filled with a lubricating fluid, for example, lubricating oil, including the internal pores of the bearing sleeve 8. The oil level of the lubricating oil is maintained within the range of the seal space S.
[0038]
When the shaft member 2 rotates, the regions (two upper and lower regions) of the inner peripheral surface 8a of the bearing sleeve 8 to be radial bearing surfaces respectively oppose the outer peripheral surface 2a1 of the shaft portion 2a via the radial bearing gap. Further, a region of the lower end surface 8c of the bearing sleeve 8 serving as a thrust bearing surface is opposed to an upper end surface 2b1 of the flange portion 2b via a thrust bearing gap, and a region of the end surface 10a of the thrust member 10 serving as a thrust bearing surface is a flange. It faces the lower end surface 2b2 of the portion 2b via the thrust bearing gap. Then, with the rotation of the shaft member 2, a dynamic pressure of the lubricating oil is generated in the radial bearing gap, and the shaft portion 2a of the shaft member 2 is rotated in the radial direction by an oil film of the lubricating oil formed in the radial bearing gap. Freely supported in a non-contact manner. Thus, a first radial bearing portion R1 and a second radial bearing portion R2 that rotatably support the shaft member 2 in the radial direction in a non-contact manner are configured. At the same time, a dynamic pressure of lubricating oil is generated in the thrust bearing gap, and the flange portion 2b of the shaft member 2 is rotatably and non-contactly supported in both thrust directions by a lubricating oil film formed in the thrust bearing gap. . Thus, a first thrust bearing portion S1 and a second thrust bearing portion S2 that rotatably support the shaft member 2 in the thrust direction in a non-contact manner are configured.
[0039]
As described above, the dynamic pressure groove 8a1 of the first radial bearing portion R1 is formed so as to be asymmetric in the axial direction with respect to the axial center m, and the axial dimension X1 of the region above the axial center m is the lower region. (FIG. 3A). Therefore, when the shaft member 2 rotates, the lubricating oil drawing force (pumping force) by the dynamic pressure groove 8a1 is relatively larger in the upper region than in the lower region. The lubricating oil filled in the gap between the inner peripheral surface 8a of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a flows downward due to the differential pressure of the pulling force, and the lubricating oil of the first thrust bearing portion S1 The gap between the inner peripheral surface 8a of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a circulates through the path of the thrust bearing gap → the axial groove 8d1 → the threaded portion P → the circumferential groove 8b1 → the radial groove 8b21. And is drawn again into the radial bearing gap of the first radial bearing portion R1. In this way, by configuring the lubricating oil to flow and circulate in the internal space of the housing 7, it is possible to prevent a phenomenon in which the pressure of the lubricating oil in the internal space is locally reduced to a negative pressure. Problems such as generation of air bubbles, leakage of lubricating oil and generation of vibration due to the generation of air bubbles can be solved. Further, even if bubbles are mixed in the lubricating oil for some reason, the bubbles are discharged from the oil surface (gas-liquid interface) of the lubricating oil in the seal space S to the outside air when circulating with the lubricating oil. The adverse effects of air bubbles are more effectively prevented.
[0040]
【The invention's effect】
The present invention has the following effects.
(1) Since there is a concave adhesive reservoir between the inner peripheral surface of the housing and the outer peripheral surface of the bearing sleeve, even if an excess amount of adhesive is generated depending on the amount of application, the excess adhesive is deposited in a concave adhesive reservoir. This prevents the adhesive from being entrapped and adversely affecting the positioning of the bearing sleeve and the bearing performance.
(2) By forming the adhesive reservoir into a shape that is gradually reduced toward both sides in the axial direction, the adhesive excessively captured in the adhesive reservoir flows to both sides in the axial direction narrowed by the capillary action, thereby reducing the original size. Since the fixing portion (filling gap between the outer peripheral surface of the bearing sleeve and the inner peripheral surface of the housing) is filled, the amount of the adhesive in the fixing portion of the bearing sleeve is not excessive or insufficient, and a stable fixing state can be obtained.
(3) The lubricating fluid filled in the internal space of the housing is caused to flow and circulate in the internal space by the slim portion, the radial groove, and the axial groove, so that the pressure of the lubricating oil in the internal space is locally reduced. By preventing the phenomenon of negative pressure from being generated, it is possible to solve problems such as generation of bubbles due to the generation of the negative pressure, leakage of lubricating oil and generation of vibration due to the generation of the bubbles. Further, when the bearing sleeve is fixed to the inner peripheral surface of the housing with an adhesive, even if the adhesive wraps around, the adhesive does not easily flow in the direction of the radial groove due to the slim portion, so that the radial direction The situation in which the groove is closed by the adhesive can be avoided.
[Brief description of the drawings]
FIG. 1 is a sectional view of a spindle motor for information equipment using a hydrodynamic bearing device according to the present invention.
FIG. 2 is a cross-sectional view showing one embodiment of a hydrodynamic bearing device according to the present invention.
3 is a sectional view of the bearing sleeve {FIG. 3 (a)}, a lower end surface {FIG. 3 (b)}, and an upper end surface {FIG. 3 (c)}.
FIG. 4 is a view showing an end surface of a thrust member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dynamic-pressure bearing device 2 Shaft member 2a Shaft part 2b Flange part 7 Housing 7a Seal part 7a2 Inner side surface 7a21 Inner diameter side region 7a22 Outer diameter side region 7c Inner peripheral surface 8 Bearing sleeve 8a Inner peripheral surface 8b Upper end surface 8b2 Circular groove 8b2 Inner diameter side region 8b21 Radial groove 8c Lower end surface 8d Outer peripheral surface 8d1 Axial groove R1 Radial bearing portion R2 Radial bearing portion S1 Thrust bearing portion S2 Thrust bearing portion U Adhesive accumulation P Nusumi portion 10 Thrust member

Claims (7)

A housing, a bearing sleeve fixed to an inner peripheral surface of the housing, a shaft member, and a shaft member, and the shaft member is provided between the bearing sleeve and the shaft member by a dynamic pressure action of lubricating oil generated in a radial bearing gap. In a hydrodynamic bearing device having a radial bearing portion for non-contact support in the radial direction,
The bearing sleeve is fixed to an inner peripheral surface of the housing with an adhesive, and a concave adhesive reservoir is provided between an inner peripheral surface of the housing and an outer peripheral surface of the bearing sleeve. Pressure bearing device. The dynamic pressure bearing device according to claim 1, wherein the adhesive reservoir is provided on an inner peripheral surface of the housing. The dynamic pressure bearing device according to claim 1, wherein the adhesive reservoir has a shape that gradually decreases toward both sides in the axial direction. A housing, a bearing sleeve fixed to the inner peripheral surface of the housing, a shaft member having a shaft portion and a flange portion, a seal portion provided at one end portion of the housing, and provided at the other end portion of the housing. A thrust portion, a radial bearing portion provided between the bearing sleeve and the shaft portion and supporting the shaft portion in a non-contact manner in a radial direction by a dynamic pressure action of lubricating oil generated in a radial bearing gap; and A thrust bearing portion provided between the thrust portion and the flange portion for supporting the flange portion in a non-contact manner in the thrust direction by a dynamic pressure action of lubricating oil generated in a thrust bearing gap; In a dynamic bearing device filled with
The inner surface of the seal portion partially contacts the inner diameter region of the one end surface of the bearing sleeve at its inner diameter region, and the outer portion of the outer diameter region is separated from the one end surface of the bearing sleeve. A hydrodynamic bearing device characterized by forming: The dynamic bearing device according to claim 4, wherein the bearing sleeve is fixed to an inner peripheral surface of the housing with an adhesive. The dynamic bearing device according to any one of claims 1 to 5, wherein the bearing sleeve is formed of a sintered metal. A motor comprising the dynamic pressure bearing device according to claim 1.

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