JP4309642B2 - Hydrodynamic bearing device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrodynamic bearing device in which a shaft member is rotatably supported in a non-contact manner by a hydrodynamic action of lubricating oil generated in a bearing gap, and a manufacturing method thereof. This bearing device is a spindle of information equipment such as magnetic disk devices such as HDD and FDD, optical disk devices such as CD-ROM, CD-R / RW and DVD-ROM / RAM, and magneto-optical disk devices such as MD and MO. It is suitable for a motor, a polygon scanner motor of a laser beam printer (LBP), or an electric device such as a small motor such as an axial fan.
[0002]
[Prior art]
In addition to high rotational accuracy, the various motors are required to have high speed, low cost, low noise, and the like. One of the components that determine the required performance is a bearing that supports the spindle of the motor, and in recent years, as this type of bearing, the use of a hydrodynamic 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 and a non-contact support that rotates a shaft member in a thrust direction. A dynamic bearing having a dynamic pressure generating groove (dynamic pressure groove) on the inner peripheral surface of the bearing sleeve or the outer peripheral surface of the shaft member is used as the radial bearing portion. As the thrust bearing portion, for example, a motion in which dynamic pressure grooves are provided on both end surfaces of the flange portion of the shaft member, or surfaces facing the flange portion (the end surface of the bearing sleeve, the end surface of the thrust member fixed to the housing, etc.). A pressure bearing is used (for example, refer to Patent Document 1).
[0004]
Usually, the bearing sleeve is fixed at a predetermined position on the inner periphery of the housing, and the thrust member is fixed to the inner peripheral portion on one end side of the housing. Further, in order to prevent the lubricating oil injected into the internal space of the housing from leaking outside, a seal portion is often provided at the other end (opening) of the housing.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-061641
[Problems to be solved by the invention]
In the above hydrodynamic bearing device, press fitting may be employed as means for fixing the thrust member to the inner peripheral portion on one end side of the housing. In some cases, after the thrust member is press-fitted, the press-fitted portion is filled with an adhesive from the outside of the housing, and the press-fitted portion is sealed with the adhesive. However, when press-fitting is employed as a means for fixing the thrust member, the following problem may occur.
[0007]
That is, each component of the hydrodynamic bearing device is cleaned after manufacturing, and fine metal powder such as cutting powder generated during processing is removed. When the thrust member is press-fitted, the outer peripheral portion of the thrust member and the housing There is a possibility that fine metal powder such as abrasion powder (hereinafter referred to as “abrasion powder”) is generated by sliding friction with the inner peripheral portion of the one end side and enters the housing. Wear powder that has entered the housing is mixed with the lubricating fluid and enters the bearing portion, which adversely affects the performance and life of the bearing.
[0008]
An object of the present invention is to prevent the wear powder from entering.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides a housing, a bearing sleeve fixed to the inner periphery of the housing, a shaft member having a shaft portion and a flange portion, and a thrust member fixed to the inner peripheral portion on one end side of the housing. A radial bearing portion provided between the bearing sleeve and the shaft portion and supporting the shaft portion in a non-contact manner in the radial direction by a dynamic pressure action of lubricating oil generated in the radial bearing gap, a bearing sleeve, a thrust member, and a flange portion, And a thrust bearing portion that supports the flange portion in a non-contact manner in the thrust direction by the dynamic pressure action of lubricating oil generated in the thrust bearing gap. A press-fitting surface that is press-fitted and fixed from one end side of the housing to the outer peripheral part of the thrust member with the adhesive interposed between the peripheral part and the inner peripheral part of one end side of the housing. The press-fitting surface has a tapered surface extending from one end on the inner side of the housing to the inner surface side inclining direction and reaching the end surface of the thrust member, and between the tapered surface of the outer peripheral portion of the thrust member and the inner peripheral portion on the one end side of the housing in, while have a inner tapered space adjacent inside side of the housing press-fit portion of the thrust member for holding the adhesive, between the one end side inner periphery of the outer peripheral portion and the housing of the thrust member, The thrust member has an outer tapered space for holding the adhesive adjacent to the press-fitted portion of the housing on the outer side of the housing, and the inner tapered space has a shape gradually reduced toward the thrust-fitted portion of the thrust member. , adhesive is held within the tapered space, solidified within the tapered inner space, the outer tapered space has a shape gradually diminished toward the press-fit portion of the thrust member, the adhesive There the held outside tapered space, provides a configuration that is solidified in the external tapered space.
[0010]
According to the above configuration, even if wear powder is generated when the thrust member is press-fitted, the wear powder is captured by the adhesive and is contained in the adhesive by solidifying the adhesive. Therefore, intrusion of wear powder accompanying press-fitting of the thrust member is prevented. In addition, since the adhesive acts as a lubricant when the thrust member is press-fitted, the generation of wear powder during press-fitting is reduced and the press-fitting operation is facilitated.
[0011]
When the thrust member is press-fitted, there is a phenomenon that the adhesive wraps around the front side of the thrust member in the press-fitting direction. If the wraparound is significant, the adhesive reaches the periphery of the shaft member and the shaft member rotates smoothly. It is also expected that this will cause problems. However, between the outer peripheral portion and the one end side inner periphery of the housing of the thrust member, since the provided internal tapered space adjacent inside side of the housing press-fit portion of the thrust member for holding the adhesive, thrust The adhesive that wraps around the front side of the member in the press-fitting direction is held on the press-fitted portion side by the capillary force of the inner tapered space, and is prevented from flowing toward the shaft member. In addition, as a result of increasing the adhesive holding effect, the effect of capturing and containing the abrasion powder by the adhesive is also increased.
[0012]
The outer peripheral portion of the thrust member has a press-fit surface that is press-fitted into the inner peripheral portion on one end side of the housing, and a tapered surface that extends in an inner diameter side inclined direction from one end of the inner side of the press-fit surface to the end surface of the thrust member. Is provided. The internal tapered space is formed between the tapered surface of the thrust member and the inner peripheral portion on one end side of the housing, and has a shape gradually reduced toward the press-fitted portion of the thrust member. Then, on the inner side of the housing, the adhesive is held in the inner tapered space and solidified in the inner tapered space.
[0013]
In addition to the internal tapered space described above, an external tapered space that holds the adhesive between the outer peripheral portion of the thrust member and the inner peripheral portion on one end side of the housing adjacent to the press-fitted portion of the thrust member on the outer side of the housing. Thus, after the thrust member is press-fitted, the press-fitted portion can be sealed with the lubricant held by the capillary force of the external tapered space. In particular, if a step portion located in the outer tapered space on the one end side of the housing and located on the outer side of the housing is provided, the adhesive remaining in the outer tapered space after the thrust member is press-fitted is provided. Since the amount increases, the sealing effect of the press-fitted portion is further enhanced.
[0014]
The external tapered space can be formed by providing a tapered surface on at least one of the outer peripheral portion of the thrust member and the inner peripheral portion on one end side of the housing. Preferably, a tapered surface is provided on the outer peripheral portion of the thrust member.
[0015]
Further, the present invention is a method for manufacturing the above-described hydrodynamic bearing in order to solve the above-described problem, and includes a step of applying an adhesive to the inner peripheral portion at one end of the housing, and applying the adhesive of the housing And a step of press-fitting a thrust member into the inner peripheral portion on the one end side.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
[0017]
FIG. 1 shows a configuration example of a spindle motor for information equipment incorporating a fluid dynamic bearing device 1 according to this embodiment. This spindle motor is used in a disk drive device such as an HDD, and includes a hydrodynamic bearing device 1 that rotatably supports the 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 to face each other with a gap in the radial direction. 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 attached to 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 is rotated by the electromagnetic force between the stator 4 and the rotor magnet 5, whereby the disk hub 3 and the shaft member 2 are rotated together.
[0018]
FIG. 2 shows the hydrodynamic 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.
[0019]
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, the first radial bearing portion R1 and the second radial bearing portion R2 are provided apart from each other in the axial direction. A first thrust bearing portion S1 is provided between the lower end surface 8c of the bearing sleeve 8 and the upper end surface 2b1 of the flange portion 2b of the shaft member 2, and the lower side of the upper end surface 10a of the thrust member 10 and the flange portion 2b. A second thrust bearing portion S2 is provided between the end surface 2b2. For convenience of explanation, the description will be given with the side of the thrust member 10 as the lower side and the side opposite to the thrust member 10 as the upper side.
[0020]
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. The inner peripheral surface 7a1 of the seal portion 7a is opposed to the tapered surface 2a2 provided on the outer periphery of the shaft portion 2a via a predetermined seal space S. Further, as shown in an enlarged view in FIG. 5, a lower end side inner peripheral portion 7c1 having a larger diameter than the inner peripheral surface 7c to which the bearing sleeve 8 is fixed is formed at the lower end portion of the side portion 7b. A step portion 7c11 facing the outside of the housing 7 is formed on the inner peripheral portion 7c1. In this embodiment, the stepped portion 7c11 has a tapered surface in the direction of gradually increasing the diameter downward.
[0021]
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 the lower end of the shaft portion 2a. The tapered surface 2a2 of the shaft portion 2a gradually decreases in diameter toward the upper side (outside of the housing 7), and functions as a centrifugal force seal by the rotation of the shaft member 2.
[0022]
The bearing sleeve 8 is formed in a cylindrical shape, for example, of a porous body made of sintered metal, particularly a sintered body of sintered metal mainly composed of copper, and is fixed at a predetermined position on the inner peripheral surface 7 c of the housing 7. .
[0023]
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 the first radial bearing portion R1 and the second radial bearing portion R2 are provided apart in the axial direction. In these two regions, for example, herringbone-shaped dynamic pressure grooves 8a1 and 8a2 as shown in FIG. 3A are formed. The upper dynamic pressure groove 8a1 is formed axially asymmetric with respect to the axial center m (the axial center of the upper and lower inclined groove regions), 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. Further, one or a plurality of axial grooves 8d1 are formed on the outer peripheral surface 8d of the bearing sleeve 8 over the entire axial length. In this example, three axial grooves 8d1 are formed at equal intervals around the circumference. 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.
[0024]
A spiral dynamic pressure groove 8c1 as shown in FIG. 3B, for example, is formed on the lower end surface 8c of the bearing sleeve 8 serving as a thrust bearing surface of the first thrust bearing portion S1. In addition, as a shape of the dynamic pressure groove, a herringbone shape, a radiation groove shape, or the like may be adopted.
[0025]
As shown in FIG. 3C, the upper end surface 8b of the bearing sleeve 8 is formed into an inner diameter side region 8b2 and an outer diameter side region 8b3 by a circumferential groove 8b1 having a V-shaped cross section provided at a substantially central portion in the radial direction. One or a plurality of radial grooves 8b21 are formed in the inner diameter side region 8b2. In this example, three radial grooves 8b21 are formed at equal intervals in the circumferential direction.
[0026]
2, the inner side surface 7a2 of the seal portion 7a partially contacts the inner diameter side region 8b2 of the upper end surface 8b of the bearing sleeve 8 at the inner diameter side region 7a21, and the outer diameter thereof. The side region 7a22 is formed in an inclined shape or a curved shape so as to be separated from the upper end surface 8b of the bearing sleeve 8. Therefore, a waste portion 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 Nusumi part P communicates with the circumferential groove 8b1, and the outer diameter side communicates with the axial groove 8d1.
[0027]
The thrust member 10 is formed of a metal material such as brass, for example, and is press-fitted into the lower end side inner peripheral portion 7 c 1 of the housing 7. As shown in FIG. 4, for example, a herringbone-shaped dynamic pressure groove 10 a 1 is formed on the upper end surface 10 a of the thrust member 10 serving as a thrust bearing surface of the second thrust bearing portion S <b> 2. In addition, you may employ | adopt spiral shape, a radiation groove shape, etc. as a shape of a dynamic pressure groove.
[0028]
The outer peripheral portion 10c of the thrust member 10 includes a press-fit surface 10c1 that is press-fitted into the lower-end-side inner peripheral portion 7c1 of the housing 7, a tapered surface 10c2 that extends from the upper end of the press-fit surface 10c1 in the inner diameter side inclination direction and reaches the upper end surface 10a. A tapered surface 10c3 extends from the lower end of the press-fit surface 10c1 in the inner diameter side inclination direction and reaches the lower end surface 10b. The press-fit surface 10c1 is parallel to the axis.
[0029]
The hydrodynamic bearing device 1 of this embodiment is assembled by the following process, for example.
[0030]
First, the bearing sleeve 8 is inserted into the inner peripheral surface 7c of the housing 7, and the upper end surface 8b is brought into contact with the inner side surface 7a2 of the seal portion 7a. Thereby, the bearing sleeve 8 is positioned with respect to the housing 7. The bearing sleeve 8 can be fixed to the inner peripheral surface 7c of the housing 7 by press fitting, bonding, combined use of pressing and bonding, or other appropriate fixing means.
[0031]
Next, the shaft member 2 is mounted on the bearing sleeve 8. 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 the radial bearing clearance is reduced by matching the outer diameter of the shaft portion 2a (measured in advance). It can be set with high accuracy.
[0032]
Thereafter, the thrust member 10 is press-fitted and fixed to a lower end side inner peripheral portion 7c1 of the housing 7 to a predetermined position under the presence of an adhesive. Specifically, as shown in an enlarged view in FIG. 5, an adhesive T is applied to the lower end portion of the lower end side inner peripheral portion 7c1 of the housing 7, and then the thrust member 10 is press-fitted into the lower end side inner peripheral portion 7c1. . Since the adhesive T serves as a lubricant when the thrust member 10 is press-fitted, the generation of wear powder during press-fitting is reduced and the press-fitting operation is facilitated.
[0033]
FIG. 6 shows a state where the press-fitting of the thrust member 10 is completed. The press-fitting surface 10c1 of the outer peripheral portion 10c of the thrust member 10 is press-fitted into the lower end side inner peripheral portion 7c1 of the housing 7 with a predetermined press-fitting allowance, and the inner space Q1 is adjacent to the press-fitted portion on the inner side of the housing 7. An external tapered space Q2 is adjacent to the outside of the housing 7. The internal tape-shaped space Q1 is formed between the upper tapered surface 10c2 of the outer peripheral portion 10c and the lower end side inner peripheral portion 7c1, and has a shape gradually reduced toward the press-fitted portion. The outer tapered space Q2 is formed between the lower tapered surface 10c3 of the outer peripheral portion 10c and the lower end side inner peripheral portion 7c1, and has a shape gradually reduced toward the press-fit portion.
[0034]
When the thrust member 10 is press-fitted, the adhesive T that has come around to the front side of the thrust member 10 in the press-fitting direction is held by the capillary force of the internal tapered space Q1. The abrasion powder M generated when the thrust member 10 is press-fitted is captured by the adhesive T in the internal tapered space Q1 and is contained in the adhesive T by the solidification of the adhesive T. Due to the holding effect of the adhesive T by the internal tapered space Q1, the flow of the adhesive T to the shaft member 2 side is prevented, and the effect of capturing and containing the wear powder M by the adhesive T is enhanced.
[0035]
Further, the lubricant T is held by the capillary force of the external tapered space Q2, and the press-fitted portion of the thrust member 10 is sealed by the lubricant T. In particular, when the step 7c11 is provided on the inner peripheral portion 7c1 at the lower end side of the housing 7 as in this embodiment, the amount of the adhesive T remaining in the external tapered space Q2 after the thrust member 10 is press-fitted increases. Therefore, the sealing effect of the press-fitted portion is further enhanced.
[0036]
When the 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 upper end surface 10a of the thrust member 10. It will be in the state accommodated in the space part between. Thereafter, the internal space of the housing 7 sealed by the seal portion 7 a 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.
[0037]
When the shaft member 2 rotates, the regions (two upper and lower regions) of the inner peripheral surface 8a of the bearing sleeve 8 are opposed to the outer peripheral surface 2a1 of the shaft portion 2a via the radial bearing gap. Further, the region that becomes the thrust bearing surface of the lower end surface 8c of the bearing sleeve 8 faces the upper end surface 2b1 of the flange portion 2b via the thrust bearing gap, and the region that becomes the thrust bearing surface of the upper end surface 10a of the thrust member 10 is It faces the lower end surface 2b2 of the flange portion 2b via a thrust bearing gap. As the shaft member 2 rotates, the 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 the lubricating oil film formed in the radial bearing gap. It is supported non-contact freely. Thus, the first radial bearing portion R1 and the second radial bearing portion R2 that support the shaft member 2 in a non-contact manner so as to be rotatable in the radial direction are configured. At the same time, the dynamic pressure of the lubricating oil is generated in the thrust bearing gap, and the flange portion 2b of the shaft member 2 is rotatably supported in both thrust directions by the oil film of the lubricating oil formed in the thrust bearing gap. . Thereby, the first thrust bearing portion S1 and the second thrust bearing portion S2 that support the shaft member 2 in a non-contact manner so as to be rotatable in the thrust direction are configured.
[0038]
As described above, the dynamic pressure groove 8a1 of the first radial bearing portion R1 is formed to be axially asymmetric with respect to the axial center m, and the axial dimension X1 of the upper region from the axial center m is the lower region. It is larger than the axial dimension X2 of {Fig. 3 (a)}. Therefore, when the shaft member 2 rotates, the lubricating oil pulling force (pumping force) by the dynamic pressure groove 8a1 is relatively larger in the upper region than in the lower region. Then, due to the differential pressure of the pulling force, 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, and the first thrust bearing portion S1 The clearance between the inner peripheral surface 8a of the bearing sleeve 8 and the outer peripheral surface 2a1 of the shaft portion 2a is circulated through the path of the thrust bearing clearance → the axial groove 8d1 → the Nusumi portion P → the circumferential groove 8b1 → the radial groove 8b21. Returning to the radial bearing gap of the first radial bearing portion R1. In this way, the structure in which the lubricating oil flows and circulates in the internal space of the housing 7 prevents a phenomenon in which the pressure of the lubricating oil in the internal space becomes a negative pressure locally, resulting in the generation of negative pressure. Problems such as generation of bubbles, leakage of lubricating oil and generation of vibration due to generation of bubbles can be solved. In addition, even if bubbles are mixed in the lubricating oil for some reason, when the bubbles circulate with the lubricating oil, it is discharged from the oil surface (gas-liquid interface) of the lubricating oil in the seal space S to the outside air. The adverse effects due to the bubbles are more effectively prevented.
[0039]
【The invention's effect】
The present invention has the following effects.
(1) Even if wear powder is generated when the thrust member is press-fitted, the wear powder is captured by the adhesive and is contained in the adhesive by solidifying the adhesive. Therefore, intrusion of wear powder accompanying press-fitting of the thrust member is prevented. In addition, since the adhesive acts as a lubricant when the thrust member is press-fitted, the generation of wear powder during press-fitting is reduced and the press-fitting operation is facilitated.
(2) between the tapered surface and the one end side inner periphery of the housing of the outer peripheral portion of the thrust member, provided inside tapered space adjacent inside side of the housing press-fit portion of the thrust member for holding the adhesive As a result , the adhesive that has slew to the front side of the thrust member in the press-fitting direction is held on the press-fitting portion side by the capillary force of the internal tapered space, and flow to the shaft member side is prevented. Therefore, the situation where the smooth rotation of the shaft member is hindered by the wraparound of the adhesive during press-fitting is avoided. Moreover, as a result of the adhesive holding effect being increased by the internal tapered space, the effect of capturing and containing the abrasion powder by the adhesive is also increased.
(3) An external taper space is provided between the outer peripheral portion of the thrust member and the inner peripheral portion on one end side of the housing so as to hold the adhesive adjacent to the press-fitted portion of the thrust member on the outer side of the housing. The press-fit portion can be sealed with a lubricant held by the capillary force of the tapered space. In particular, if a step portion located in the outer tapered space on one end side of the housing and located on the outer side of the housing is provided, the adhesive remaining in the outer tapered space when the thrust member is press-fitted is provided. Since the amount increases, the sealing effect of the press-fitted portion is further enhanced.
[Brief description of the drawings]
FIG. 1 is a cross-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 an embodiment of a hydrodynamic bearing device according to the present invention.
3 is a cross-sectional view of a bearing sleeve {FIG. 3 (a)}, a lower end face {FIG. 3 (b)}, and an upper end face {FIG. 3 (c)}.
FIG. 4 is a view {FIG. 4 (a)} showing an upper end surface of a thrust member, and a cross-sectional view {FIG. 4 (b)}.
FIG. 5 is a partially enlarged cross-sectional view showing the periphery of the inner peripheral portion on the lower end side of the housing.
FIG. 6 is a partially enlarged cross-sectional view showing a state in which a thrust member is press-fitted into the inner peripheral portion on the lower end side of the housing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dynamic pressure bearing apparatus 2 Shaft member 2a Shaft part 2b Flange part 7 Housing 7c Inner peripheral surface 7c1 Lower end side inner peripheral part 7c11 Step part 8 Bearing sleeve 8a Inner peripheral surface 10 Thrust member 10c Outer peripheral part 10c2 Taper surface 10c3 Taper surface R1 Radial Bearing portion R2 Radial bearing portion S1 Thrust bearing portion S2 Thrust bearing portion T Adhesive Q1 Internal tapered space Q2 External tapered space

Claims (5)

A housing, a bearing sleeve fixed to the inner periphery of the housing, a shaft member having a shaft portion and a flange portion, a thrust member fixed to an inner peripheral portion on one end side of the housing, the bearing sleeve and the shaft portion; A radial bearing portion that supports the shaft portion in a radial direction by a dynamic pressure action of lubricating oil generated in a radial bearing gap, and is provided between the bearing sleeve, the thrust member, and the flange portion, In a hydrodynamic bearing device comprising a thrust bearing portion that non-contact supports the flange portion in the thrust direction by the hydrodynamic action of lubricating oil generated in a thrust bearing gap,
The thrust member is press-fitted and fixed from one end side of the housing to the inner peripheral portion on one end side of the housing under the presence of an adhesive,
A press-fitting surface that is press-fitted into the outer peripheral portion of the housing on one end side inner peripheral portion of the thrust member, and extends from the one end of the press-fitting surface on the inner side of the housing in an inner diameter side inclined direction to the end surface of the thrust member. Has a tapered surface,
An internal tapered space that holds the adhesive adjacent to the press-fitted portion of the thrust member on the inner side of the housing between the tapered surface of the outer peripheral portion of the thrust member and the inner peripheral portion of the one end of the housing. while Yes, it said between the outer peripheral portion of the thrust member and the one end side inner periphery of the housing, an external tapered to hold the adhesive and adjacent the external side of the housing press-fit portion of the thrust member Have space,
The inner tapered space has a shape gradually reduced toward the press-fitted portion of the thrust member, and the adhesive is held in the inner tapered space, and is solidified in the inner tapered space .
The external tapered space has a shape gradually reduced toward the press-fitted portion of the thrust member, and the adhesive is held in the external tapered space and solidified in the external tapered space. The hydrodynamic bearing device. Wherein an outer peripheral portion of the thrust member, the dynamic pressure bearing device according to claim 1, characterized in that it comprises a tapered surface for forming the outer tapered space. One end inner periphery of the housing, the located outside the tapered inner space, a fluid dynamic bearing device according to claim 1, characterized in that it comprises a step portion facing the outer side of the housing. A method of manufacturing a dynamic pressure bearing according to any one of claims 1 to 3, a step of applying an adhesive to one side inner peripheral portion of said housing, one end of the adhesive of the housing has been applied And a step of press-fitting the thrust member into the inner peripheral portion. Motor comprising the fluid dynamic bearing device according to any one of claims 1-3.

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