JP4754418B2 - Hydrodynamic bearing device - Google Patents

Description

  The present invention relates to a hydrodynamic bearing device that rotatably supports a shaft member with a lubricating film in a bearing gap.

  Due to its high rotational accuracy and quietness, the hydrodynamic bearing device is an information device, for example, a magnetic disk drive device such as HDD, an optical disk drive device such as CD-ROM, CD-R / RW, DVD-ROM / RAM, MD, MO, etc. Suitable for small motors such as fan motors used for spindle motors such as magneto-optical disk drive devices, etc., polygon scanner motors for laser beam printers (LBP), color wheels for projectors, cooling fans for electrical equipment, etc. It can be used.

  For example, the hydrodynamic bearing device (dynamic pressure bearing device) shown in Patent Document 1 is provided with a shaft member and a seal member that protrudes from the shaft member to the outer diameter and forms a seal space on the outer periphery. . The shaft member and the seal member are fixed by a method such as adhesion, press-fitting, or a combination of adhesion and press-fitting.

JP 2005-321089 A

  However, when the sealing member and the shaft member are fixed by bonding, a jig for fixing both members until the adhesive is completely solidified is required. Further, when the seal member is press-fitted into the shaft member, wear powder generated at the time of press-fitting may enter the inside of the bearing as contamination, which may reduce the bearing performance. In addition, when both bonding and press-fitting are used, it is difficult to interpose an adhesive on the mating surfaces of both members. Therefore, the adhesive overflowing from the mating surfaces penetrates into the internal space of the bearing device, and the bearing May adversely affect performance.

  The subject of this invention is providing the hydrodynamic bearing apparatus which can fix another member to the outer peripheral surface of a shaft member easily and firmly.

  In order to solve the above problems, the present invention provides a shaft member, a flange portion fixed to the outer peripheral surface of the shaft member, and a lubricating film formed in a radial bearing gap facing the outer peripheral surface of the shaft member in the radial direction. In a hydrodynamic bearing device having a radial bearing portion to be supported on a thrust bearing and a thrust bearing portion to support the shaft member in a thrust direction with a lubricating film generated in a thrust bearing gap, the inner peripheral surface of the flange portion is fitted to the outer peripheral surface of the shaft member. The two members are combined by caulking and bonding.

  Thus, in this invention, fixation with a shaft member and a flange part is performed using caulking and adhesion | attachment together. Specifically, the inner peripheral surface of the flange portion is fitted to the outer peripheral surface of the shaft member, and both members are temporarily fixed by caulking, and the adhesive is interposed in the gap between the two members. Fix it. As described above, since the flange portion is fitted to the shaft member, no abrasion powder is generated at the time of insertion, and there is no possibility of contamination inside the bearing. Moreover, the jig which fixes both members by a subsequent process becomes unnecessary by crimping both members and temporarily fixing. Moreover, since the places other than the crimped part among the fitting surfaces of both members are in a gap fitting state, an adhesive can be easily interposed.

  The caulking of both members can be performed, for example, at the inner diameter end of the flange portion. Further, the adhesive pool can be formed by a concave portion formed by plastic deformation by caulking, for example, by caulking the inner diameter end of the flange portion.

  When caulking the flange portion, if the flange portion is solid, it is difficult to be deformed by caulking, so that it may not be sufficiently caulked or an unplanned place may be deformed. Therefore, if a concave portion is formed in advance on the inner peripheral surface of the flange portion, deformation of the flange portion due to caulking can be absorbed by this concave portion. As a result, the deformation of the flange portion is facilitated, sufficient caulking is possible, and deformation due to caulking can be concentrated in the vicinity of the recess.

  Further, for example, if a crimped portion is provided on the end surface of the flange portion on the bearing inner side, a space inside the bearing, for example, a portion facing the thrust bearing gap may be deformed, and the bearing performance may be deteriorated. Therefore, it is desirable to provide the to-be-clamped portion on the end surface on the air release side.

  Thus, according to the present invention, a fluid dynamic bearing device capable of easily and firmly fixing other members to the outer peripheral surface of the shaft member is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 conceptually shows a configuration example of a spindle motor for information equipment incorporating a fluid dynamic bearing device 1 according to a first embodiment of the present invention. This spindle motor for information equipment is used in a disk drive device such as an HDD, and includes a dynamic pressure bearing device 1, a rotor (disk hub) 3 attached to a shaft member 2 of the dynamic pressure bearing device 1, and a radius, for example. A stator coil 4a and a rotor magnet 4b that are opposed to each other with a gap in the direction, and a bracket 5 are provided. The stator coil 4 a is attached to the outer periphery of the bracket 5, and the rotor magnet 4 b is attached to the inner periphery of the disk hub 3. The disk hub 3 holds one or more disks D such as magnetic disks on the outer periphery thereof. When the stator coil 4a is energized, the rotor magnet 4b is rotated by an electromagnetic force generated between the stator coil 4a and the rotor magnet 4b, and the disk hub 3 and the shaft member 2 are rotated together therewith.

  FIG. 2 shows a fluid dynamic bearing device 1 used in the spindle motor. The hydrodynamic bearing device 1 includes a shaft member 2, a first seal portion 9 and a second seal portion 10 as flange portions provided so as to protrude from the shaft member 2 to the outer diameter, and the shaft member 2 inserted on the inner periphery. The bearing member 6 is configured as a main component. In the embodiment shown in FIG. 2, the bearing member 6 is composed of a housing 7 and a sleeve portion 8 separately. In the following description, for convenience of description, the description will be given with the side where the end of the shaft member 2 protrudes from the opening of the housing 7 as the upper side and the opposite side in the axial direction as the lower side.

  Between the inner peripheral surface 8a of the sleeve portion 8 and the outer peripheral surface 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 T1 is provided between the upper end surface 8b of the sleeve portion 8 and the lower end surface 9b of the first seal portion 9, and the lower end surface 8c of the sleeve portion 8 and the upper side of the second seal portion 10 are provided. A second thrust bearing portion T2 is provided between the end surface 10b.

  The shaft member 2 is made of a metal material such as stainless steel, or has a hybrid structure of metal and resin. The shaft member 2 as a whole has a shaft shape with substantially the same diameter, and an intermediate portion is provided with a relief portion 2b formed with a slightly smaller diameter than the other portions, and the first and second seal portions 9, 10 A recessed portion, for example, a circumferential groove 2c is formed at the fixed position.

  The housing 7 is formed in a cylindrical shape by, for example, injection molding of a resin material, and the inner peripheral surface 7a is a straight cylindrical surface having the same diameter. The outer peripheral surface of the housing 7 is fixed to the inner peripheral surface of the bracket 5 shown in FIG.

  The resin forming the housing 7 is mainly a thermoplastic resin. For example, as an amorphous resin, polysulfone (PSF), polyethersulfone (PES), polyphenylsulfone (PPSF), polyetherimide (PEI) As the crystalline resin, liquid crystal polymer (LCP), polyether ether ketone (PEEK), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or the like can be used. The type of filler to be filled in the resin is not particularly limited. For example, as the filler, fibrous filler such as glass fiber, whisker-like filler such as potassium titanate, and scaly filler such as mica. A fibrous or powdery conductive filler such as carbon fiber, carbon black, graphite, carbon nanomaterial, or metal powder can be used. These fillers may be used alone or in combination of two or more. In this embodiment, as a material for forming the housing 7, a resin material in which 2 to 8 wt% of a carbon fiber or a carbon nanotube as a conductive filler is mixed with a liquid crystal polymer (LCP) as a crystalline resin is used.

  In addition, the housing 7 can also be formed of a soft metal material such as brass or an aluminum alloy, or other metal materials.

  The sleeve portion 8 is formed in a cylindrical shape, for example, a porous body made of sintered metal, particularly a sintered metal porous body mainly composed of copper, and is press-fitted into a predetermined position on the inner peripheral surface 7a of the housing 7. It is fixed by means such as adhesion or press-fit adhesion. In addition, the sleeve part 8 can also be formed with metal materials, such as a copper alloy, besides a sintered metal.

  The inner peripheral surface 8a of the sleeve portion 8 is provided with two upper and lower regions that are radial bearing surfaces of the first radial bearing portion R1 and the second radial bearing portion R2, and are separated in the axial direction. For example, herringbone-shaped dynamic pressure grooves 8a1 and 8a2 as shown in FIG. 3A are formed. The dynamic pressure grooves 8a1 and 8a2 may be formed continuously in the axial direction in addition to being separated in the axial direction as shown in FIG. Alternatively, only one of the dynamic pressure grooves 8a1 and 8a2 may be formed. Further, an axial groove 8d1 is formed at one or a plurality of locations on the outer peripheral surface 8d of the sleeve portion 8.

  The upper end surface 8b of the sleeve portion 8 is provided with a region serving as a thrust bearing surface of the first thrust bearing portion T1, and in this region, for example, a spiral-shaped dynamic pressure groove 8b1 as shown in FIG. It is formed. The lower end surface 8c of the sleeve portion 8 is provided with a region serving as a thrust bearing surface of the first thrust bearing portion T1, and in this region, for example, a spiral-shaped dynamic pressure as shown in FIG. A groove 8c1 is formed.

  The first seal portion 9 and the second seal portion 10 are formed in a ring shape from a resin material or a metal material.

  The outer peripheral surface 9a of the first seal portion 9 forms a first seal space S1 having a predetermined volume with the inner peripheral surface 7a of the upper end opening of the housing 7, and the outer peripheral surface of the second seal portion 10. 10 a forms a second seal space S <b> 2 having a predetermined volume with the inner peripheral surface 7 a of the lower end opening of the housing 7. In this embodiment, the outer peripheral surface 9a of the first seal portion 9 and the outer peripheral surface 10a of the second seal portion 10 are each formed into a tapered surface shape that gradually increases in diameter toward the outside of the bearing device. Therefore, both the seal spaces S1 and S2 have a tapered shape that is gradually reduced in the direction of approaching each other. When the shaft member 2 is rotated, the lubricating oil in both the seal spaces S1 and S2 is drawn in a direction in which the seal space is narrowed by a drawing action by a capillary force and a drawing action by a centrifugal force at the time of rotation. Thereby, the leakage of the lubricating oil from the inside of the housing 7 is effectively prevented. In order to prevent oil leakage more reliably, the upper end surface 7b and the lower end surface 7c of the housing 7, the upper end surface 9c of the first seal portion 9, and the lower end surface 10c of the second seal portion 10 are respectively coated with an oil repellent coating. It can also be formed.

  The first and second seal spaces S <b> 1 and S <b> 2 have a buffer function that absorbs a volume change amount associated with a temperature change of the lubricating oil filled in the internal space of the housing 7. Within the assumed temperature change range, the oil level is always in both seal spaces S1, S2. In order to achieve this, the sum of the volumes of both the seal spaces S1, S2 is set to be larger than at least the volume change amount associated with the temperature change of the lubricating oil filled in the internal space.

  Hereinafter, a method of fixing the first seal portion 9 to the shaft member 2 will be described with reference to FIG.

  A concave portion is formed in advance on the inner peripheral surface 9d of the first seal portion 9, and in this embodiment, an annular groove 9d1 having a rectangular cross section as shown in FIG. The shape of the recess is not limited to this, and the cross section may be formed in a semicircular shape. Or you may provide a recessed part in the several place spaced apart in the circumferential direction. The diameter of the inner peripheral surface 9 d of the first seal portion 9 is set slightly larger than the outer diameter of the shaft member 2.

  First, the first seal portion 9 is extrapolated from above the shaft member 2, and the lower end surface 9b of the first seal portion 9 is brought into contact with the upper end surface 11a of the fixing jig 11 to be arranged at a predetermined position (FIG. 4). (See (a)). At this time, the fitting between the inner peripheral surface 9d of the first seal portion 9 and the outer peripheral surface 2a of the shaft member 2 is a clearance fit. Therefore, for example, it is possible to avoid a possibility that the fitting surface is damaged as in the case of press-fitting, or that wear powder due to this damage is mixed into the bearing as contamination.

  Next, in a state where the first seal portion 9 is positioned by the fixing jig 11, the inner diameter end of the upper end surface 9c of the first seal portion 9 is caulked from above by the caulking jig 12 (see FIG. 4B). The caulking jig 12 is formed in a columnar shape, and has a spherical surface portion 12a on the inner diameter side of the lower end portion thereof and a tapered surface 12b on the outer diameter side of the lower end portion thereof. This caulking is performed at a plurality of locations separated at substantially equal intervals in the entire circumference or in the circumferential direction. A concave portion 9c1 (a portion to be crimped) is formed by caulking the inner diameter end of the upper end surface 9c of the first seal portion 9 with the arc portion 12a of the caulking jig 12, and at the same time, the inner peripheral surface of the first seal portion 9 The upper end portion of 9d is plastically deformed and crimped to the outer peripheral surface 2a of the shaft member 2. At this time, since plastic deformation due to caulking is absorbed by the annular groove 9d1 of the inner peripheral surface 9d of the first seal portion 9, the inner diameter end of the upper end surface 9c of the first seal portion 9 can be easily plastically deformed. . Further, since plastic deformation due to caulking can be concentrated in the vicinity of the annular groove 9d1, it is possible to prevent other parts, for example, the lower end surface 9b of the first seal portion 9 facing the thrust bearing gap from being deformed. In addition, even if there is no annular groove 9d1 provided on the inner peripheral surface 9d of the first seal portion 9, the annular groove 9d1 can be caulked without any problem and the deformation of other parts due to the caulking can be ignored. May be omitted.

Thus, since the 1st seal part 9 is temporarily fixed to the predetermined position of the outer peripheral surface 2a of the shaft member 2 by crimping the 1st seal part 9, the fixing jig 11 becomes unnecessary after crimping. . In addition, when caulking the inner diameter end of the upper end surface 9c of the first seal portion 9 over the entire circumference, the caulking jig 12 may be formed in an annular shape.

  After temporarily fixing the first seal portion 9 and the shaft member 2, an adhesive is injected with an injection needle 13 between the outer peripheral surface 2a of the shaft member 2 and the inner peripheral surface 9d of the first seal portion 9 (see FIG. 4 (c)). At this time, since the fitting surface of both members is a gap fitting, an adhesive can be easily interposed. Moreover, since the recessed part 9c1 formed in the inner diameter end of the upper end surface 9c of the first seal portion 9 by the above-described caulking can be used as an adhesive injection port, it can be easily injected. Further, the concave portion 9c1 and the annular groove 9d1 formed in the seal portion 9 function as an adhesive reservoir, whereby the adhesion force between the first seal portion 9 and the shaft member 2 is enhanced. Furthermore, by sealing the gap between the fitting surfaces of both members by injecting the adhesive, it is possible to prevent the lubricant filled in the bearing from leaking out of the gap.

  By the way, in this embodiment, as shown in FIG. 2, while the upper end surface 9c of the 1st seal | sticker part 9 is open | released to air | atmosphere, the lower end surface 9b faces a thrust bearing clearance gap. If the lower end face 9b facing the thrust bearing gap is caulked, the accuracy of the gap width of the thrust bearing gap may be reduced, and the supporting force in the thrust direction may be reduced. As described above, by caulking the upper end surface 9c on the atmosphere opening side, it is possible to prevent the possibility of lowering the bearing performance.

  In the present embodiment, the second seal portion 10 is fixed to the shaft member 2 by means such as adhesion, press fitting, or welding. For example, when the second seal portion 10 is fixed by press fitting, the fitting surfaces of both members may be damaged as described above. However, since the second seal portion 10 is fixed to the lower end portion of the shaft member 2, the press-fitting stroke (the distance to be pushed in in the press-fitted state) is relatively short, and both members are not damaged so severely. Of course, the second seal portion 10 may be fixed to the shaft member 2 in the same manner as the first seal portion 9.

  The first and second seal portions 9 and 10 are fixed to the shaft member 2 by fixing either one of the seal portions to the shaft member 2 and then mounting the sleeve portion 8 on the shaft member 2. The other seal part is fixed with the part 8 interposed therebetween. Thereafter, this assembly is inserted into the inner peripheral surface 7 a of the housing 7, and the outer peripheral surface 8 d of the sleeve portion 8 is fixed to the inner peripheral surface 7 a of the housing 7. The sleeve portion 8 can be fixed to the housing 7 by appropriate means such as adhesion, press-fitting, combined use of adhesion and press-fitting, and welding (ultrasonic welding). When the assembly is completed in this way, the internal space of the housing 7 sealed by the seal portions 9 and 10 is filled with, for example, lubricating oil as a lubricating fluid including the internal pores of the sleeve portion 8.

  When the shaft member 2 rotates, the regions (two upper and lower regions) of the inner peripheral surface 8a of the sleeve portion 8 that are opposed to the outer peripheral surface 2a of the shaft member 2 are opposed to each other via a radial bearing gap. Further, a region serving as a thrust bearing surface of the upper end surface 8b of the sleeve portion 8 faces the lower end surface 9b of the first seal portion 9 via a predetermined thrust bearing gap, and the thrust bearing of the lower end surface 8c of the sleeve portion 8 is formed. The surface area is opposed to the upper end surface 10b of the second seal portion 10 via a predetermined thrust bearing gap. With the rotation of the shaft portion, the dynamic pressure of the lubricating oil is generated in the radial bearing gap, and the shaft member 2 is non-contactably supported in the radial direction by the lubricating oil film formed in the radial bearing gap. The 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 shaft member 2 and the seal portions 9 and 10 are supported in a non-contact manner so as to be rotatable in the thrust direction by the lubricating oil film formed in the thrust bearing gap. The Thereby, the 1st thrust bearing part T1 and the 2nd thrust bearing part T2 which non-contact-support the shaft member 2 rotatably in a thrust direction are comprised.

  In the present embodiment, the axial groove 8d1 formed in the outer peripheral surface 8d of the sleeve portion 8 causes the outer diameter end of the thrust bearing clearance of the first thrust bearing portion T1 and the thrust bearing clearance of the second thrust bearing portion T2. Is communicated with the outer diameter end. Thereby, since the pressure balance of the lubricating oil filled in the bearing device can be properly maintained, it is possible to prevent a decrease in bearing performance due to the generation of a local negative pressure. In the present embodiment, the dynamic pressure generating portions of the radial bearing portions R1 and R2 are formed vertically symmetrical with respect to the center in the axial direction. The lubricating oil in the bearing gap can be forced to flow. According to this, since the lubricating oil can be circulated through the radial bearing gap, the thrust bearing gap, and the axial groove 8d1, generation of negative pressure inside the bearing can be more effectively prevented. Further, when the problem due to the generation of the negative pressure does not occur, the axial groove 8d1 can be omitted, and the outer peripheral surface 8d of the sleeve portion 8 can be a cylindrical surface.

  The present invention is not limited to the above embodiment. Hereinafter, other embodiments of the present invention will be described. In the following description, parts having the same configuration and function as those of the above embodiment are given the same reference numerals, and the description thereof is omitted.

  FIG. 5 shows a fluid dynamic bearing device 1 according to a second embodiment of the present invention. In the hydrodynamic bearing device 1, the lower opening of the housing 7 is closed by the lid member 14, and the hook-shaped portion 2 d is provided at the lower end of the shaft member 2. The lid member 14 is formed in a substantially disc shape from a metal material or a resin material. The lid member 14 is inserted into the large-diameter inner peripheral surface 7d of the housing 7, and is fixed in contact with the shoulder surface 7e extending inward from the upper end of the large-diameter inner peripheral surface 7d. A second thrust bearing portion T2 is formed between the upper end surface 2d1 of the flanged portion 2d and the lower end surface 8c of the sleeve portion 8.

  FIG. 6 shows a fluid dynamic bearing device 1 according to a third embodiment of the present invention. In this dynamic pressure bearing device 1, a disk hub 3 as a flange portion is fixed to the upper end portion of the outer peripheral surface 2 a of the shaft member 2. The disk hub 3 includes a disk portion 3a that covers the upper opening of the housing 7, a cylindrical portion 3b that extends downward from the outer diameter end of the disk portion 3a, and a flange portion 3c that protrudes from the cylindrical portion 3b to the outer diameter. And a disk mounting surface 3d provided on the upper end surface of the flange portion 3c. A first thrust bearing portion T1 is formed between the lower end surface 3a1 of the disk portion 3a and the upper end surface 7b of the housing 7. A tapered surface 7f that gradually increases in diameter upward is provided above the outer peripheral surface of the housing 7, and a gap width gradually increases upward between the tapered surface 7f and the inner peripheral surface 3b1 of the cylindrical portion 3b. A reduced seal space S is formed. A rotor magnet 4b is attached to the outer peripheral portion of the cylindrical portion 3b via a yoke 16. A cylindrical surface 7 g provided below the outer peripheral surface of the housing 7 is fixed to the inner periphery of the bracket 5.

  The disk hub 3 and the shaft member 2 are fixed as follows. That is, an annular groove 3a30 is provided in advance on the inner circumferential surface 3a3 of the disk portion 3a, and the inner diameter end of the upper end surface 3a2 of the disk portion 3a is caulked from above at a predetermined position of the shaft member 2, thereby forming the recess 3a20. Both members are temporarily fixed. Thereafter, an adhesive is injected into the gap between the two members from the recess 3a20 to fix the two members.

  In the above embodiment, an example in which the flange portion and the shaft member are temporarily fixed by caulking the flange portion is shown. However, the present invention is not limited thereto, and for example, both the members are temporarily secured by caulking the shaft member. It may be fixed.

  In the above embodiment, the case where the adhesive is injected between the two members after the flange portion has been crimped is shown. On the contrary, the adhesive is interposed between the two members. From the above, the flange portion can be crimped.

  In the above embodiment, the radial bearing portions R1 and R2 are configured to generate a dynamic pressure action on the lubricating oil by the herringbone-shaped dynamic pressure grooves 8a1 and 8a2. However, the present invention is not limited to this. A shaped dynamic pressure groove, a step bearing, or a multi-arc bearing may be formed.

  In addition, the thrust bearing portions T1 and T2 are configured to generate a dynamic pressure action on the lubricating oil by the spiral-shaped dynamic pressure grooves 8b1 and 8c1, but the present invention is not limited thereto, and for example, a herringbone-shaped dynamic pressure groove or A step bearing or a corrugated bearing (a corrugated step bearing) may be formed.

  Furthermore, in the above embodiment, the case where the dynamic pressure grooves 8a1 and 8a2 of the first and second radial bearing portions R1 and R2 are formed in the inner peripheral surface 8a of the sleeve portion 8 is exemplified. It can also form in the surface which opposes, ie, the outer peripheral surface 2a of the shaft member 2. FIG. Further, the case where the dynamic pressure grooves 8b1 and 8c1 of the first and second thrust bearing portions T1 and T2 are formed on both end surfaces 8b and 8c of the sleeve portion or the upper end surface 7b of the housing 7 is illustrated. The surface facing through the thrust bearing gap, that is, the lower end surface 9b of the first seal portion 9, the upper end surface 10b of the second seal portion 10, the upper end surface 2d1 of the bowl-shaped portion 2d, or the disk portion 3a of the disc hub 3 It can also be formed on the lower end surface 3a1.

  In the above embodiment, the lubricating oil is used as the lubricating fluid that fills the internal space of the hydrodynamic bearing device 1. However, the present invention is not limited to this. For example, a gas such as air, lubricating grease, magnetic fluid, etc. Can also be used.

  Further, the hydrodynamic bearing device of the present invention is not limited to the spindle motor used in the disk drive device such as the HDD as described above, but is used for information used under high-speed rotation, such as a spindle motor for driving a magneto-optical disk of an optical disk. It can also be suitably used as a fan motor for rotating shaft support in a small motor for equipment, a polygon scanner motor of a laser beam printer, or a cooling fan for electrical equipment.

It is sectional drawing which shows the spindle motor incorporating the dynamic pressure bearing apparatus. 1 is a cross-sectional view showing a fluid dynamic bearing device 1 according to a first embodiment of the present invention. (A) Axial direction sectional view of sleeve part 8, (b) Top view, (c) Bottom view. FIG. 6 is a cross-sectional view showing a fixing process between the first seal portion 9 and the shaft member 2. It is sectional drawing which shows the hydrodynamic bearing apparatus 1 which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the hydrodynamic bearing apparatus 1 which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dynamic pressure bearing apparatus 2 Shaft member 6 Bearing member 7 Housing 8 Sleeve part 9 1st seal part (flange part)
9c1 Concave part (Casting part)
9d1 annular groove (concave)
DESCRIPTION OF SYMBOLS 10 2nd seal part 11 Fixing jig 12 Clamping jig 13 Injection needle R1, R2 Radial bearing part S1, S2 Seal space T1, T2 Thrust bearing part

Claims (4)

A shaft member, a flange portion fixed to the outer peripheral surface of the shaft member, a radial bearing portion that supports the shaft member in the radial direction with a lubricating film generated in a radial bearing gap facing the outer peripheral surface of the shaft member, and a thrust bearing clearance In a hydrodynamic bearing device including a thrust bearing portion that supports a shaft member in a thrust direction with a generated lubricating film,
The inner peripheral surface of the flange portion is fitted to the outer peripheral surface of the shaft member, both the members are joined by caulking and bonding, and the plastic deformation of the to-be-clamped portion is a recess formed in advance on the inner peripheral surface of the flange portion. Absorbed hydrodynamic bearing device.   The hydrodynamic bearing device according to claim 1, wherein a portion to be crimped is provided at an inner diameter end of the flange portion.   The hydrodynamic bearing device according to claim 1, wherein an adhesive reservoir is formed by plastic deformation by the caulking.   The hydrodynamic bearing device according to claim 1, wherein a crimped portion is provided on an end surface of the flange portion on the air release side.

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