KR20120084143A - Hydrodynamic bearing assembly and motor including the same - Google Patents

Hydrodynamic bearing assembly and motor including the same Download PDF

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Publication number
KR20120084143A
KR20120084143A KR1020110005507A KR20110005507A KR20120084143A KR 20120084143 A KR20120084143 A KR 20120084143A KR 1020110005507 A KR1020110005507 A KR 1020110005507A KR 20110005507 A KR20110005507 A KR 20110005507A KR 20120084143 A KR20120084143 A KR 20120084143A
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KR
South Korea
Prior art keywords
stopper
shaft
bearing assembly
sleeve
circumferential surface
Prior art date
Application number
KR1020110005507A
Other languages
Korean (ko)
Inventor
노지애
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 KR1020110005507A priority Critical patent/KR20120084143A/en
Publication of KR20120084143A publication Critical patent/KR20120084143A/en

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    • 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
    • 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
    • H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
    • H02K5/163—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields radially supporting the rotary shaft at only one end of the rotor
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/08—Structural association with bearings
    • H02K7/086—Structural association with bearings radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
    • 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
    • F16C2370/00—Apparatus relating to physics, e.g. instruments
    • F16C2370/12—Hard disk drives or the like

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

Abstract

The hydrodynamic bearing assembly according to an embodiment of the present invention includes a sleeve in which a shaft is inserted and supported; A stopper coupled to one end of the shaft and protruding in an outer diameter direction of the shaft to have a constant diameter; And a radial dynamic pressure groove formed on at least one of an outer circumferential surface of the stopper and an inner circumferential surface of the sleeve corresponding to the outer circumferential surface of the stopper.

Figure P1020110005507

Description

Hydrodynamic bearing assembly and motor including the same

The present invention relates to a fluid dynamic bearing assembly and a motor including the same. More particularly, the present invention relates to a fluid dynamic bearing assembly and a motor including the same to improve the durability and impact resistance of the stopper by changing the shape and structure of the stopper. .

A motor for obtaining a driving force is installed in a device of a hard disk drive (HDD) or an optical disc drive (ODD), which is one of information storage devices of a computer.

The motor may provide a space in which the shaft can rotate by the bearing, and such a dynamic hydrodynamic bearing may be used as the bearing.

On the other hand, in order for the shaft to be supported and rotated in the bearing by fluid dynamic pressure, the shaft is inserted into and supported in the sleeve of the bearing.

However, when the shaft is supported by the fluid dynamic pressure, there is a disadvantage in that the shaft is forced to leave under the force in the upper direction of the shaft.

To solve this problem, a stopper may be coupled to the shaft.

However, when the stopper is coupled to the shaft, the space corresponding to the shaft axial length occupied by the stopper cannot play a role in generating fluid dynamic pressure, which is disadvantageous in miniaturization and thinning of the motor.

In addition, since the thickness of the stopper in the axial thickness of the stopper is reduced in order to reduce the space occupied by the motor, there is a problem that the durability and impact resistance of the stopper are deteriorated.

Therefore, there is a need for research to improve the durability or impact resistance of the stopper while efficiently using the space occupied by the stopper in the bearing assembly.

An object of the present invention is to provide a fluid dynamic bearing assembly and a motor including the same by changing the structure of the stopper constituting the hydrodynamic bearing assembly and the formation position of the dynamic pressure generating groove, thereby improving the durability and impact resistance of the stopper. It is done.

The hydrodynamic bearing assembly according to an embodiment of the present invention includes a sleeve in which a shaft is inserted and supported; A stopper coupled to one end of the shaft and protruding in an outer diameter direction of the shaft to have a constant diameter; And a radial dynamic pressure groove formed on at least one of an outer circumferential surface of the stopper and an inner circumferential surface of the sleeve corresponding to the outer circumferential surface of the stopper.

In addition, the stopper of the hydrodynamic bearing assembly according to an embodiment of the present invention may be characterized in that the length in the shaft axial direction is at least 20% or more of the entire length of the shaft.

In addition, the stopper of the hydrodynamic bearing assembly according to an embodiment of the present invention may be formed integrally with the shaft.

In addition, the stopper of the hydrodynamic bearing assembly according to an embodiment of the present invention may be characterized in that the thrust dynamic groove is formed on at least one of the upper surface and the lower surface.

In addition, the stopper of the hydrodynamic bearing assembly according to an embodiment of the present invention may be characterized in that the coupling groove for coupling with the shaft is formed.

In addition, the lower portion of the shaft of the hydrodynamic bearing assembly according to an embodiment of the present invention may be characterized in that the engaging projection of the outer diameter relatively smaller than the outer diameter of the shaft for coupling with the stopper.

In addition, the lower portion of the sleeve of the hydrodynamic bearing assembly according to an embodiment of the present invention may be characterized in that the over-injury prevention portion of the inner diameter is larger than the inner diameter of the sleeve to prevent over-injury of the stopper. .

Motor according to another embodiment of the present invention is a hydrodynamic bearing assembly according to an embodiment of the present invention; A stator coupled to an outer circumferential surface of the sleeve and having a core wound around a coil for generating a rotational driving force; And a rotor mounted on one surface of the magnet facing the winding coil to be rotatable with respect to the stator.

The fluid dynamic bearing assembly and the motor including the same according to the present invention can improve durability and impact resistance of the stopper by changing the structure and the assembly method of the stopper. Accordingly, the effect of preventing the leakage of the fluid also occurs.

On the other hand, by forming a dynamic pressure generating groove in the shaft axial space occupied by the stopper, there is an advantage that the shaft can be rotated stably and the motor can be made smaller and thinner.

1 is a schematic cross-sectional view showing a motor according to an embodiment of the present invention.
FIG. 2 is an enlarged schematic cross-sectional view of part A of FIG. 1.
3 is a cut perspective view schematically showing only the stopper according to an embodiment of the present invention.
4 and 5 are cross-sectional views and cut-away perspective views schematically showing a first embodiment of a modified stopper according to one embodiment of the present invention in correspondence with FIGS. 2 and 3.
6 and 7 are cross-sectional views and cut-away perspective views schematically showing a second embodiment of the modified stopper according to one embodiment of the present invention, corresponding to FIGS. 2 and 3.

Hereinafter, with reference to the drawings will be described in detail a specific embodiment of the present invention. 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 falling within the scope of the inventive concept may readily be suggested, but are also considered to be within the scope of the present invention.

The same reference numerals are used to designate the same components in the same reference numerals in the drawings of the embodiments.

1 is a schematic cross-sectional view illustrating a motor according to an embodiment of the present invention, FIG. 2 is a schematic cross-sectional view showing an enlarged portion A of FIG. 1, and FIG. 3 is a schematic diagram illustrating only a stopper according to an embodiment of the present invention. It is a perspective view of cutting.

1 to 3, a motor according to an embodiment of the present invention may include a fluid dynamic bearing assembly 1, a stator 2, and a rotor 3.

The hydrodynamic bearing assembly 1 may include a shaft 10, a sleeve 20, a base cover 40, and a stopper 30. Specific embodiments of the fluid dynamic bearing assembly 1 will be described below, and the motor according to the present invention may have all the specific features of each embodiment of the fluid dynamic bearing assembly 1.

First, when defining terms for the direction, the outer diameter direction means the direction of the outer end of the rotor 3 relative to the shaft 10, the inner diameter direction of the shaft 10 relative to the shaft 10 Means the central direction. In addition, the axial direction refers to the up and down direction with respect to the shaft 10, as shown in FIG.

The shaft 10 may be inserted into the sleeve 20 to support the rotation of the rotor 3. As a result, the rotor 3 may naturally rotate without friction with the sleeve 20.

The shaft 10 may couple the stopper 30 to the bottom thereof. To this end, the shaft 10 may be coupled to the stopper 30 without deformation of the shape, but may serve as a locking step 12 of the stopper 30 to couple with the stopper 30. It can also be modified.

That is, a coupling protrusion 11 having an outer diameter relatively smaller than the outer diameter of the shaft 10 may be formed below the shaft 10. As a result, the engaging jaw 12 may be formed in the shaft 10 as much as the outer diameter difference from the coupling protrusion 11. The function of this locking step 12 will be described later in the description of the stopper 30.

The sleeve 20 may support the shaft 10 such that an upper end of the shaft 10 protrudes upward in the axial direction.

Here, the shaft 10 is inserted to have a small gap with the shaft hole of the sleeve 20, and the micro gap is filled with lubricating fluid.

The sleeve 20 has a bypass channel formed to communicate the upper and lower portions of the sleeve 20, so that the pressure of the lubricating fluid in the fluid dynamic bearing assembly 1 can be dispersed to maintain equilibrium, Bubbles and the like present in the fluid dynamic bearing assembly 1 may be moved to be discharged by circulation.

On the other hand, the inner circumferential surface of the sleeve 20 may be formed a radial dynamic pressure groove 50 for generating dynamic pressure for supporting the rotation of the shaft 10, the radial dynamic pressure groove 50 is a spiral shape or Herringbone shape and the like.

Such a radial dynamic groove 50 may be formed on the outer circumferential surface of the shaft 10 as well as the sleeve 20. That is, the radial dynamic pressure groove 50 may be formed in at least one of the sleeve 20 and the shaft 10.

In addition, the radial dynamic pressure groove 50 may be formed in two stages in the upper and lower portions of the sleeve 20 or the shaft 10 in the axial direction, thereby generating a balanced radial dynamic pressure of the shaft It becomes possible to support 10 more stably.

The radial dynamic pressure groove 50 may be formed on the outer circumferential surface of the stopper 30 and the inner circumferential surface of the sleeve 20 corresponding to the outer circumferential surface of the stopper 30, and the description thereof will be described with the description of the stopper 30. It will be described later.

On the other hand, the lower portion of the sleeve 20 may be formed with an over-injury prevention portion 21 of an inner diameter relatively larger than the inner diameter of the sleeve 20. As a result, the stopper 30 can be prevented from being injured due to the rotation of the shaft 10.

The base cover 40 may be coupled to the lower end of the sleeve 20 in order to prevent the fluid used to generate dynamic pressure from leaking from the fluid dynamic bearing assembly 1.

Bonding or welding may be used to couple the base cover 40 to the sleeve 20.

Spot welding may be used when joining by welding, and there is an advantage in that the bonding force with the sleeve 20 may be relatively large.

On the other hand, the bonding method having a relatively smaller bonding force than the welding method may increase the bonding force with the sleeve 20 by using a structure and a bonding method that increases the bonding area with the sleeve 20.

In addition, the base cover 40 may function as a bearing for supporting a lower surface of the shaft 10 by receiving lubricating fluid in the gap between the sleeve 20.

The stopper 30 may serve to prevent the shaft 10 from moving upward in the axial direction when the shaft 10 rotates in the sleeve 20.

To this end, the stopper 30 may be coupled to one end of the shaft 10 and protrude in the outer diameter direction of the shaft 10 to have a constant diameter.

On the other hand, the stopper 30 may be characterized in that the length in the axial direction of at least 20% or more of the entire length of the shaft 10.

As a result, the stopper 30 may have a length in the axial direction relatively thicker than that of the existing stopper, thereby improving durability and impact resistance of the stopper 30.

That is, by increasing the thickness of the stopper 30, it is possible to improve the stress of the stopper 30 against the vertical force affecting the axial direction.

In addition, the improvement of durability and impact resistance of the stopper 30 also brings additional advantages of preventing the leakage of fluid due to the breakage of the stopper 30.

The stopper 30 may be combined with the shaft 10 separately after manufacture, or may be integrally formed with the shaft 10 from the beginning.

When the stopper 30 is formed integrally with the shaft 10, there is an advantage in that problems such as assembly failure that may occur when the stopper 30 and the shaft 10 are coupled to each other may be eliminated.

If the stopper 30 is manufactured separately from the shaft 10 and then coupled, a problem such as poor assembly occurs, but such a problem may be solved by the coupling protrusion 11 formed on the shaft 10. .

That is, since the inner diameter of the stopper 30 may be smaller than the outer diameter of the upper portion of the shaft 10 except for the engaging protrusion 11, the upper portion of the shaft 10 having a larger diameter than the stopper 30. Is to be able to act as a locking jaw 12 when the stopper 30 is coupled.

As a result, the locking jaw 12 serves as a reference plane to allow the stopper 30 to be coupled perpendicularly to the axial direction, thereby eliminating the assembly failure of the stopper 30.

Meanwhile, a radial dynamic pressure groove 50 may be formed on at least one of an outer circumferential surface of the stopper 30 and an inner circumferential surface of the sleeve 20 corresponding to the outer circumferential surface of the stopper 30.

As a result, the space in the axial direction of the shaft 10 occupied by the stopper 30 can be utilized, resulting in an advantage that the motor can be made smaller and thinner.

That is, in the past, when the radial dynamic pressure groove 50 is formed, the side of the stopper 30 may not be utilized to utilize the wasted space.

On the other hand, the stopper 30 may be formed with a coupling groove 31 for coupling with the shaft 10, a description thereof will be described later with reference to Figs.

In addition, the stopper 30 may have a thrust dynamic pressure groove 60 formed on at least one of an upper surface and a lower surface thereof, which will be described later with reference to FIGS. 6 and 7.

The stator 2 may be a fixed structure including a coil 5 generating a predetermined magnitude of electromagnetic force when a power is applied and a plurality of cores 4 on which the coil 5 is wound.

The core 4 is fixedly disposed on an upper portion of the base 6 on which a printed circuit board (not shown) on which a pattern circuit is printed is provided, and on the upper surface of the base 6 corresponding to the coil 5. A plurality of coil holes having a predetermined size may be formed to expose the lower portion (5), and the coil 5 may be electrically connected to the printed circuit board (not shown) to supply external power.

The outer circumferential surface of the sleeve 20 is press-fitted and fixed to the base 6, and a core 4 around which the coil 5 is wound may be inserted, and an inner surface of the base 6 or the sleeve 20 may be inserted therein. It may be assembled by applying an adhesive to the outer surface of the assembly or by welding.

The rotor 3 is a rotational structure rotatably provided with respect to the stator 2, and a rotor case having an outer circumferential surface of a ring-shaped magnet 7 corresponding to each other at regular intervals from the core 4 ( 8) may be included.

In addition, the magnet 7 is provided with a permanent magnet in which the N pole and the S pole are alternately magnetized in the circumferential direction to generate a magnetic force of a predetermined intensity.

Here, the rotor case 8 extends in the outer diameter direction from the hub base 8a and the hub base 8a to be press-fitted to the upper end of the shaft 10 and is bent downward in the axial direction to the rotor 3. It may be made of a magnet support (8b) for supporting the magnet (7).

4 and 5 are cross-sectional views and cut-away perspective views schematically showing a first embodiment of a modified stopper according to one embodiment of the present invention in correspondence with FIGS. 2 and 3.

4 and 5, the stopper 30 may be provided with a coupling groove 31 for engaging with the shaft 10. As a result, the stopper 30 may also come into contact with the lower surface of the shaft 10, thereby generating an advantage of improving the bonding force due to an increase in the contact area.

On the other hand, as the area of the lower surface of the stopper 30 increases, the area in which the thrust dynamic pressure grooves 60 formed on the lower surface of the stopper 30 can also be increased, thereby increasing the thrust dynamic pressure. do.

The shape of the shaft 10 does not need to be modified to correspond to the coupling groove 31, but as described above, the coupling protrusion 11 is formed to remove assembly defects with the stopper 30. It is also possible.

6 and 7 are cross-sectional views and cut-away perspective views schematically showing a second embodiment of the modified stopper according to one embodiment of the present invention, corresponding to FIGS. 2 and 3.

6 and 7, the stopper 30 may have a thrust dynamic pressure groove 60 formed on at least one of an upper surface and a lower surface. Thereby, the stopper 30 can also serve as a thrust plate.

That is, the thrust dynamic groove 60 formed on at least one of the upper and lower surfaces of the stopper 30 can function as a bearing for supporting the lower surface of the shaft 10.

The thrust dynamic pressure groove 60 may have a spiral shape or a herringbone shape, such as the radial dynamic pressure groove described above.

1: fluid dynamic bearing assembly 2: stator
3: rotor 4: core
5: coil 6: base
7: magnet 8: rotor case
10: shaft 11: engaging projection
12: engaging jaw 20: sleeve
21: over-injury prevention part 30: stopper
31: engaging groove 40: base cover
50: radial dynamic groove 60: thrust dynamic groove

Claims (8)

A sleeve into which the shaft is inserted and supported;
A stopper coupled to one end of the shaft and protruding in an outer diameter direction of the shaft to have a constant diameter; And
A radial dynamic pressure groove formed in at least one of an outer circumferential surface of the stopper and an inner circumferential surface of a sleeve corresponding to the outer circumferential surface of the stopper;
Fluid dynamic bearing assembly comprising a. The method of claim 1,
And the stopper has a length in the shaft axial direction of at least 20% or more relative to the entire length of the shaft. The method of claim 1,
And the stopper is integrally formed with the shaft. The method of claim 1,
The stopper is a fluid dynamic bearing assembly, characterized in that the thrust dynamic groove is formed on at least one of the upper surface and the lower surface. The method of claim 1,
The stopper is a hydrodynamic bearing assembly, characterized in that the coupling groove is formed for engaging with the shaft. The method of claim 1,
The lower portion of the shaft is a hydrodynamic bearing assembly characterized in that the engaging projection of the outer diameter relatively smaller than the outer diameter of the shaft is formed to engage with the stopper. The method of claim 1,
A hydrodynamic bearing assembly having an overdiameter of an inner diameter relatively larger than the inner diameter of the sleeve is formed in the lower portion of the sleeve to prevent oversurge of the stopper. A fluid dynamic bearing assembly according to any one of claims 1 to 7;
A stator coupled to an outer circumferential surface of the sleeve and having a core wound around a coil for generating a rotational driving force; And
A rotor mounted on one surface of a magnet facing the winding coil so as to be rotatable with respect to the stator;
A motor comprising a.
KR1020110005507A 2011-01-19 2011-01-19 Hydrodynamic bearing assembly and motor including the same KR20120084143A (en)

Priority Applications (1)

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KR1020110005507A KR20120084143A (en) 2011-01-19 2011-01-19 Hydrodynamic bearing assembly and motor including the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110005507A KR20120084143A (en) 2011-01-19 2011-01-19 Hydrodynamic bearing assembly and motor including the same

Publications (1)

Publication Number Publication Date
KR20120084143A true KR20120084143A (en) 2012-07-27

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