KR20130000785A - Hydrodynamic fluid bearing assembly - Google Patents

Hydrodynamic fluid bearing assembly Download PDF

Info

Publication number
KR20130000785A
KR20130000785A KR1020110061523A KR20110061523A KR20130000785A KR 20130000785 A KR20130000785 A KR 20130000785A KR 1020110061523 A KR1020110061523 A KR 1020110061523A KR 20110061523 A KR20110061523 A KR 20110061523A KR 20130000785 A KR20130000785 A KR 20130000785A
Authority
KR
South Korea
Prior art keywords
shaft
thrust member
sleeve
dynamic
groove
Prior art date
Application number
KR1020110061523A
Other languages
Korean (ko)
Inventor
유창조
Original Assignee
삼성전기주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 삼성전기주식회사 filed Critical 삼성전기주식회사
Priority to KR1020110061523A priority Critical patent/KR20130000785A/en
Publication of KR20130000785A publication Critical patent/KR20130000785A/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C32/00—Bearings not otherwise provided for
    • F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
    • F16C32/0629—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion
    • F16C32/064—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion the liquid being supplied under pressure
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/20—Driving; Starting; Stopping; Control thereof
    • G11B19/2009—Turntables, hubs and motors for disk drives; Mounting of motors in the drive
    • G11B19/2036—Motors characterized by fluid-dynamic bearings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K5/00—Casings; Enclosures; Supports
    • H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
    • H02K5/15—Mounting arrangements for bearing-shields or end plates
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C2380/00—Electrical apparatus
    • F16C2380/26—Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

A hydrodynamic bearing assembly according to an embodiment of the present invention includes a shaft, a sleeve rotatably supporting the shaft, a thrust member having a conical shape installed at a lower end of the shaft, and a lubricating fluid installed at a lower end of the sleeve. It includes a cover member for preventing the leakage of the upper surface of the cover member and the bottom surface of the thrust member may be formed to be flat to suppress the dynamic pressure generated by the dynamic pressure groove during the rotation of the shaft.

Description

Hydrodynamic fluid bearing assembly

The present invention relates to a fluid dynamic bearing assembly, and more particularly, to a fluid dynamic bearing assembly in which a lubricating fluid is filled in a bearing gap.

Small spindle motors, typically used in hard disk drives (HDDs), include a hydrodynamic bearing assembly, and a lubricant such as oil in the bearing clearance formed between the shaft and the sleeve of the hydrodynamic bearing assembly. Sieve is filled. As oil filled in the bearing gap is pumped, fluid dynamic pressure is formed to rotatably support the shaft.

That is, in general, the fluid dynamic bearing assembly generates dynamic pressure through a dynamic groove to achieve stability of motor rotational drive.

On the other hand, with the recent reduction in the recording disk drive apparatus, the spindle motor is also required to be thinner and smaller. However, there is a problem in that sufficient rotational rigidity is not obtained when the spacing between dynamic pressure grooves, that is, the span length, is shortened according to the demand for thinning and miniaturizing the spindle motor.

In order to prevent this, the thickness of each component is generally made thinner to increase the span length.

However, by making the thickness of each component thinner in this way, there is a problem in terms of fastening strength and fastening precision. That is, when an impact is applied from the outside, there is a problem in that the broken or combined components of the respective components are separated.

An object of the present invention is to provide a fluid dynamic bearing assembly capable of improving rotational characteristics.

It is also an object of the present invention to provide a fluid dynamic bearing assembly capable of reducing breakage of a thrust member.

A hydrodynamic bearing assembly according to an embodiment of the present invention includes a shaft, a sleeve rotatably supporting the shaft, a thrust member having a conical shape installed at a lower end of the shaft, and a lubricating fluid installed at a lower end of the sleeve. It includes a cover member for preventing the leakage of the upper surface of the cover member and the bottom surface of the thrust member may be formed to be flat to suppress the dynamic pressure generated by the dynamic pressure groove during the rotation of the shaft.

The sleeve may include an installation part having a shape corresponding to the shape of the thrust member, and a dynamic pressure groove may be formed on at least one of an inclined surface of the installation part and an outer surface of the thrust member disposed opposite to the inclined surface of the installation part.

At least one of an inner surface of the sleeve and an outer circumferential surface of the shaft may have upper and lower radial dynamic grooves for generating fluid dynamic pressure when the shanghai shaft rotates.

The upper radial dynamic pressure groove may have a herringbone shape, and the lower radial dynamic pressure groove may have a spiral shape to more effectively raise the pressure on the lower side of the lower radial dynamic pressure groove.

The sleeve may be provided with a oil storage portion formed to be disposed between the upper and lower radial dynamic pressure grooves.

The dynamic pressure groove may have a herringbone or spiral shape to perform in pumping to prevent excessive pressure increase between the thrust member and the cover member.

According to the present invention, it is possible to prevent the over-injury of the shaft through the thrust member having a conical shape, it is possible to increase the span length has the effect of improving the rotational characteristics.

In addition, by coupling the thrust member having a conical shape to the shaft, the coupling force between the shaft and the thrust member can be increased, and the damage of the thrust member can be reduced even when an impact is applied from the outside.

1 is a schematic cross-sectional view showing a spindle motor having a hydrodynamic bearing assembly according to an embodiment of the present invention.
2 is a partially cutaway exploded perspective view showing a fluid dynamic bearing assembly according to an embodiment of the present invention.
3 to 4 is an operation diagram for explaining the operation of the hydrodynamic bearing assembly according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventive concept. Other embodiments which fall within the scope of the inventive concept may be easily suggested, but are also included within the scope of the present invention.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a schematic cross-sectional view showing a spindle motor having a fluid dynamic bearing assembly according to an embodiment of the present invention, FIG. 2 is a partially cutaway exploded perspective view showing a fluid dynamic bearing assembly according to an embodiment of the present invention, and FIG. 3 to 4 is an operation diagram for explaining the operation of the hydrodynamic bearing assembly according to an embodiment of the present invention.

1 to 4, the hydrodynamic bearing assembly 100 according to an embodiment of the present invention includes a shaft 110, a sleeve 120, a thrust member 130, and a cover member 140. Can be.

On the other hand, the spindle motor 10 is provided with a hydrodynamic bearing assembly 100 according to an embodiment of the present invention as an example, a motor applied to the recording disk drive device for rotating the recording disk, the stator 20 and large It may be made of a rotor (40).

The stator 20 refers to all fixing members except for the rotating member, and may include a base member 22, a sleeve 120, a cover member 140, a stator core 24, and the like.

The rotor 40 refers to a member that is supported and rotated by the stator 20, and may include a rotor case 42, a magnet 44, a thrust member 130, and the like.

Looking briefly about the rotation drive method of the rotor 40, the rotor case 42 is a body 42a is formed with a fastening hole 42c to which the shaft 110 is pressed and fastened, and the annular magnet ( 44 may be composed of a magnet coupling portion (42b) installed on the inner surface.

In addition, the magnet 44 installed on the magnet coupling part 42b may be made of a permanent magnet in which N poles and S poles are alternately magnetized in the circumferential direction to generate a magnetic force of a predetermined intensity.

In addition, the stator core 24 provided in the stator 20 is disposed on the outer circumferential surface of the sleeve housing 22a formed on the base member 22 so as to face the magnet 44 whose tip is installed on the magnet engaging portion 42b. do.

The coil 26 is wound around the stator core 24.

On the other hand, when power is supplied to the coil 26 wound on the stator core 24, the rotor case 42 may be caused by electromagnetic interaction between the stator core 24 on which the coil 26 is wound and the magnet 44. Will rotate.

At this time, the rotor case 42 is rotated in conjunction with the shaft 110, so that the rotor 40 including the rotor case 42 is rotated.

Here, when defining terms for the direction, the axial direction refers to the up and down direction relative to the shaft 110 in Figure 1, the radial direction relative to the shaft 110 or the outer end direction of the rotor case 42 or rotor The center direction of the shaft 110 is referred to the outer end of the case 42, and the circumferential direction means the direction of rotation along the outer circumferential surface of the shaft 110.

The shaft 110 is rotatably installed in the sleeve 120 to rotate in conjunction with the rotor case 42 when the rotor case 42 is rotated. That is, the shaft 110 is rotated in conjunction with the magnet case 44 and the rotor case 42 is rotated by the electromagnetic interaction between the stator core 24, the coil 26 is wound.

On the other hand, when the shaft 110 is installed in the sleeve 120, the outer circumferential surface of the shaft 110 is disposed to be spaced apart from the inner circumferential surface of the sleeve 120 by a predetermined interval, thereby forming a bearing gap. The bearing gap is filled with lubricating fluid.

The sleeve 120 is fixed to the sleeve housing 22a of the base member 22 and rotatably supports the shaft 110. To this end, the sleeve 120 may have a cylindrical shape to form an installation hole 122 in which the shaft 110 is installed.

In addition, the lower end of the sleeve 120 may be provided with a mounting portion 124 is formed indented to the upper side, the cover member 140 is installed.

Meanwhile, an installation part 126 having a shape corresponding to the shape of the thrust member 130 may be provided at the lower end of the sleeve 120. That is, the installation part 126 may be indented upward from the mounting part 124 in the axial direction.

The thrust member 130 is installed at the lower end of the shaft 110 and may have a conical shape. The thrust member 130 may be inserted into the installation portion 126 of the sleeve 120.

That is, the thrust member 130 may be formed so that the outer diameter of the upper side is smaller than the outer diameter of the lower side to have a conical shape. The thrust member 130 may be fixedly installed at the lower end of the shaft 110 so that the thrust member 130 may be inserted into the installation part 126 of the sleeve 120 when the shaft 110 is installed in the sleeve 120.

In addition, since the thrust member 130 has a conical shape, the thickness of the thrust member 130 is thicker than when the thrust member 130 has a disc shape, and thus, the breakage of the thrust member 130 can be reduced when an external impact is applied. have. In addition, deformation of the thrust member 130 may be further reduced due to an increase in the thickness of the thrust member 130.

Furthermore, when the thrust member 130 is installed on the shaft 110, the contact area between the thrust member 130 and the shaft 110 may be increased, and thus the coupling force between the thrust member 130 and the shaft 110 may be increased. Can be.

On the other hand, the installation unit 126 may have a shape corresponding to the shape of the thrust member 130.

The cover member 140 is installed at the lower end of the sleeve 120 to prevent leakage of lubricating fluid. That is, the cover member 140 is fixed to the mounting portion 124 provided at the lower end of the sleeve 120 by adhesive or / and welding to prevent leakage of the lubricating fluid.

On the other hand, the upper surface of the cover member 140 and the bottom surface of the thrust member 130 may be formed to be flat to suppress the generation of dynamic pressure caused by the dynamic groove during the rotation of the shaft (110). That is, the upper surface of the cover member 140 and the lower surface of the thrust member 130 are not formed with a dynamic pressure groove for generating the thrust dynamic pressure.

Accordingly, dynamic pressure may not be generated by the lubricating fluid filled between the upper surface of the cover member 140 and the lower surface of the thrust member 130.

In addition, a dynamic pressure groove 150 may be formed on at least one of the inclined surface of the mounting portion 126 and the outer surface of the thrust member 130 disposed to face the inclined surface of the mounting portion 126. In addition, the dynamic pressure groove 150 may have a herringbone or spiral shape to prevent the pressure between the thrust member 130 and the cover member 140 from being excessively increased.

In addition, the dynamic groove 150 flows a lubricating fluid into a bearing gap formed by the shaft 110 and the sleeve 120 to prevent an excessive increase in pressure between the thrust member 130 and the cover member 140. The pumping function may be performed.

Meanwhile, at least one of an inner surface of the sleeve 120 and an outer circumferential surface of the shaft 110 may have upper and lower radial dynamic grooves 160 and 170 that generate fluid dynamic pressure when the shaft 110 rotates.

In addition, the upper radial dynamic pressure groove 160 may have a herringbone shape, and the lower radial dynamic pressure groove 170 may have a spiral shape so as to efficiently increase the pressure on the lower side of the lower radial dynamic pressure groove 170.

That is, the upper radial dynamic groove 160 may be disposed on an upper side of the shaft 110 and the sleeve 120, and the lower radial dynamic groove 170 may be disposed on a lower side than the upper radial dynamic groove 160. have.

And, as described above, since the upper radial dynamic pressure groove 160 has a herringbone shape, and the lower radial dynamic pressure groove 170 has a spiral shape, the upper surface of the cover member 140 and the bottom surface of the thrust member 130. The lubricating fluid flows through the formed bearing clearances so that the pressure increases more efficiently.

Meanwhile, as shown in FIG. 2, the span length S is disposed to face the region where the maximum dynamic pressure is generated while the lubricating fluid is pumped by the upper radial dynamic groove 160 and the outer circumferential surface of the thrust member 130. The lubricating fluid is pumped by the dynamic pressure groove 150 formed in the installation part 126, and refers to the distance from the region where the maximum dynamic pressure is generated.

However, in the present invention, a dynamic pressure groove 150 is formed in the mounting portion 126 disposed opposite to the thrust member 130, so that the span length may be further increased as compared with the case where only the upper and lower radial dynamic pressure grooves 160 and 170 are formed. It can be.

As a result, the rotation characteristics of the shaft 110 may be improved. That is, the shaft 110 is supported by the dynamic pressure generated while the lubricating fluid is pumped by the upper and lower radial dynamic pressure grooves 160 and 170 and the dynamic pressure groove 150.

On the other hand, as the distance (ie, span length) of the supported portion increases, the shaft 110 may be stably rotated without shaking. However, since the span length may be increased as described above, the rotation characteristics of the shaft 110 may be further improved.

Then, when the shaft 110 is rotated, the lubricating fluid flows from the upper side of the shaft 110 to the bearing gap formed by the thrust member 130 and the cover member 140, wherein the thrust member 130 and the cover member The pressure of the bearing clearance formed by 140 is raised.

However, an excessive increase in pressure may be prevented by the dynamic groove 150 formed in the mounting portion 126 of the sleeve 120, thereby reducing the over-injury of the shaft 110.

On the other hand, when the shaft 110 is raised, the gap between the outer peripheral surface of the thrust member 130 and the bearing gap formed by the inclined surface of the mounting portion 126 is narrowed, so that the outer peripheral surface of the thrust member 130 and the mounting portion 126 The pressure in the bearing clearance formed by the inclined surface is increased.

In this case, a force in the thrust direction downward in the axial direction is generated by the increased pressure, and eventually the shaft 110 can be prevented from being injured.

Furthermore, when the shaft 110 rises, the gap between the bearing gap formed by the outer circumferential surface of the thrust member 130 and the inclined surface of the mounting portion 126 is narrowed and the radial force in the radial direction is increased due to the increased pressure. Can be generated and eventually increase the bearing stiffness.

In addition, the sleeve 120 may be provided with a reservoir 128 formed to be disposed between the upper and lower radial dynamic grooves 160 and 170. The oil reservoir 128 provides a space in which the lubricating fluid is stored when the shaft 110 stops, and then serves to allow the lubricating fluid to flow to the lower side of the shaft 110 more quickly when the shaft 110 is rotated. .

In addition, the sleeve 120 may not be provided with a circulation hole for circulation of the lubricating fluid. Accordingly, the pressure of the bearing gap formed by the thrust member 130 and the cover member 140 may be increased more quickly.

In addition, since the circulation hole is not provided in the sleeve 120, the pressure of the bearing gap formed by the thrust member 130 and the cover member 140 may be prevented from being distributed through the circulation hole, and further, the thrust member ( Although the pressure between the bearing gap formed by the 130 and the cover member 140 is increased and the shaft 110 is inclined, the shaft 110 may be returned to the center position more quickly.

As described above, when the shaft 110 rotates by the thrust member 130 having a conical shape, it is possible to reduce the over-injury of the shaft 110. That is, when the shaft 110 rotates and floats, the gap between the outer circumferential surface of the thrust member 130 and the bearing gap formed by the inclined surface of the mounting portion 126 is narrowed, so that the outer circumferential surface and the mounting portion 126 of the thrust member 130 are narrowed. The pressure of the bearing gap formed by the inclined surface of the is increased.

In this case, a force in the thrust direction toward the lower side in the axial direction is generated by the increased pressure, and an over-injury of the shaft 110 can be reduced by the force in the downward direction in the axial direction.

In addition, radially radial forces are generated at the same time as the radially downward force due to the increased pressure, and the bearing stiffness can be increased by such radial forces.

On the other hand, the overpressure of the shaft 110 is prevented from excessively increasing the pressure of the bearing gap formed by the thrust member 130 and the cover member 140 by the dynamic pressure groove 150 formed in the installation portion 126. Can be further reduced.

In addition, since the span length can be increased by the dynamic groove 150 formed in the mounting portion 126 disposed to face the thrust member 130, the rotational characteristics of the shaft 110 can be improved.

In addition, since the thrust member 130 has a conical shape, the thickness of the thrust member 130 becomes thicker than when the thrust member 130 has a disc shape, and thus, the breakage of the thrust member 130 may be reduced when an external impact is applied. have.

In addition, deformation of the thrust member 130 may be further reduced due to an increase in the thickness of the thrust member 130.

Furthermore, when the thrust member 130 is installed on the shaft 110, the contact area between the thrust member 130 and the shaft 110 may be increased, and thus the coupling force between the thrust member 130 and the shaft 110 may be increased. Can be.

10: spindle motor 100: fluid dynamic bearing assembly
110: shaft 120: sleeve
130: thrust member 140: cover member

Claims (6)

shaft;
A sleeve rotatably supporting the shaft;
A thrust member having a conical shape installed at a lower end of the shaft; And
A cover member installed at a lower end of the sleeve to prevent leakage of lubricating fluid;
Including;
And a top surface of the cover member and a bottom surface of the thrust member are formed to be flat to suppress the generation of dynamic pressure caused by the dynamic groove during rotation of the shaft. The method of claim 1,
The sleeve has a mounting portion having a shape corresponding to the shape of the thrust member, and at least one of the inclined surface of the mounting portion and the outer surface of the thrust member disposed opposite to the inclined surface of the mounting portion is a hydrodynamic bearing formed with a dynamic groove assembly. The method of claim 2,
At least one of an inner surface of the sleeve and an outer circumferential surface of the shaft is formed with upper and lower radial dynamic grooves for generating fluid dynamic pressure when the shanghai shaft rotates. The method of claim 3,
And the upper radial dynamic groove has a herringbone shape, and the lower radial dynamic groove has a spiral shape to more effectively raise the pressure on the lower side of the lower radial dynamic groove. The method of claim 3,
The sleeve has a fluid dynamic bearing assembly is provided with a reservoir formed to be disposed between the upper, lower radial hydrodynamic groove. The method of claim 3,
And said dynamic pressure groove has a herringbone or spiral shape to perform in pumping to prevent excessive increase in pressure between said thrust member and said cover member.
KR1020110061523A 2011-06-24 2011-06-24 Hydrodynamic fluid bearing assembly KR20130000785A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110061523A KR20130000785A (en) 2011-06-24 2011-06-24 Hydrodynamic fluid bearing assembly

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110061523A KR20130000785A (en) 2011-06-24 2011-06-24 Hydrodynamic fluid bearing assembly

Publications (1)

Publication Number Publication Date
KR20130000785A true KR20130000785A (en) 2013-01-03

Family

ID=47834171

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020110061523A KR20130000785A (en) 2011-06-24 2011-06-24 Hydrodynamic fluid bearing assembly

Country Status (1)

Country Link
KR (1) KR20130000785A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108869541A (en) * 2018-01-12 2018-11-23 至玥腾风科技投资集团有限公司 A kind of control method of transverse bearing, rotor-support-foundation system and transverse bearing

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108869541A (en) * 2018-01-12 2018-11-23 至玥腾风科技投资集团有限公司 A kind of control method of transverse bearing, rotor-support-foundation system and transverse bearing
WO2019137025A1 (en) * 2018-01-12 2019-07-18 至玥腾风科技投资集团有限公司 Radial bearing, rotor system and method for controlling radial bearing
CN108869541B (en) * 2018-01-12 2024-04-02 刘慕华 Radial bearing, rotor system and control method of radial bearing

Similar Documents

Publication Publication Date Title
JP2011002024A (en) Bearing apparatus, spindle motor, and disk drive apparatus
KR101422913B1 (en) Hydrodynamic bearing assembly and spindle motor having the same
KR101133419B1 (en) Motor device
KR20130088355A (en) Spindle motor
KR101250624B1 (en) Hydrodynamic bearing assembly and motor including the same
KR20130062636A (en) Spindle motor
KR101197968B1 (en) motor
KR20130123253A (en) Hydrodynamic bearing apparatus and spindle motor having the same
KR101153546B1 (en) Motor and driving device of recording disk including the same
KR20130000785A (en) Hydrodynamic fluid bearing assembly
KR20130102733A (en) Hydrodynamic bearing assembly and motor including the same
KR20120125735A (en) Hyperdynamic fluid bearing assembly and motor having the same
KR20130061258A (en) Spindle motor
KR20130011286A (en) Spindle motor
KR101320278B1 (en) Spindle motor
KR101350601B1 (en) Spindle motor
KR20140003710A (en) Spindle motor
KR20120140068A (en) Spindle motor
KR20130011629A (en) Hydrodynamic bearing assembly and motor including the same
KR20130073672A (en) Hydrodynamic bearing assembly and motor including the same
KR20130011285A (en) Spindle motor
KR20150088341A (en) Spindle Motor
KR20120130506A (en) Motor and driving device of recording disk including the same
KR20130088996A (en) Spindle motor
KR20120126866A (en) hyperdynamic bearing assembly

Legal Events

Date Code Title Description
A201 Request for examination
E601 Decision to refuse application