KR20130073672A - 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
KR20130073672A
KR20130073672A KR1020110141638A KR20110141638A KR20130073672A KR 20130073672 A KR20130073672 A KR 20130073672A KR 1020110141638 A KR1020110141638 A KR 1020110141638A KR 20110141638 A KR20110141638 A KR 20110141638A KR 20130073672 A KR20130073672 A KR 20130073672A
Authority
KR
South Korea
Prior art keywords
thrust plate
lubricating fluid
bearing assembly
cap member
shaft
Prior art date
Application number
KR1020110141638A
Other languages
Korean (ko)
Inventor
신현호
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 KR1020110141638A priority Critical patent/KR20130073672A/en
Publication of KR20130073672A publication Critical patent/KR20130073672A/en

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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
    • F16C17/00—Sliding-contact bearings for exclusively rotary movement
    • F16C17/04—Sliding-contact bearings for exclusively rotary movement for axial load only
    • F16C17/045—Sliding-contact bearings for exclusively rotary movement for axial load only with grooves in the bearing surface to generate hydrodynamic pressure, e.g. spiral groove thrust bearings
    • 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
    • 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

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Sliding-Contact Bearings (AREA)

Abstract

PURPOSE: A hydrodynamic bearing assembly and a motor including the same are provided to suppress the movement of the interface of a lubricating fluid formed between a thrust plate and a cap member, thereby preventing leakage of the lubricating fluid. CONSTITUTION: A hydrodynamic bearing assembly (100) comprises a sleeve (120), a thrust plate (130), a cap member (140), and a pressure reduction unit (135). The sleeve supports a shaft (110) to be rotatable. The thrust plate is arranged on the shaft to face the top surface of the sleeve. The cap member is arranged on the top surface of the thrust plate. Lubricating fluid is sealed in a gap between the cap member and the thrust plate. The pressure reduction unit is formed on the top surface of the thrust plate and suppresses the movement of the interface of the lubricating fluid.

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, and more particularly, to a fluid dynamic bearing assembly and a motor including the same to suppress the movement of the gas-liquid interface of the lubricating fluid.

A hard disk drive (HDD), which is one of information storage devices, is a device that reproduces data stored on a disk using a read / write head or records data on a disk.

Such a hard disk drive requires a disk drive capable of driving a disk, and a small spindle motor is used for the disk drive.

In such a compact spindle motor, a fluid dynamic bearing assembly is used, and a lubricating fluid is interposed between a shaft, which is one of the rotating members of the fluid dynamic bearing assembly, and a sleeve, which is one of the fixing members, to form a shaft by the fluid pressure generated in the lubricating fluid. Will be supported.

The amount of lubricating fluid injected into the fluid dynamic bearing assembly may be leaked to the outside by an impact or the amount thereof may be reduced by evaporation. This phenomenon prevents the fluid dynamic bearing from generating pressure, and thus the performance and life of the spindle motor. Will cause problems.

That is, the interface of the lubricating fluid retreats due to an external impact and then rises strongly, thereby exceeding the surface tension at the interface of the lubricating fluid, thereby causing the phenomenon of leakage of the lubricating fluid.

Therefore, in order to increase the driving life of the hydrodynamic bearing and to improve the driving stability, research to prevent the leakage of the lubricating fluid is urgently needed.

Patent Document 1 described in the following prior art document discloses an invention in which a lubricating fluid is sealed between a cap member and a thrust plate.

Republic of Korea Patent Publication No. 2010-0069198

An object according to an embodiment of the present invention is to provide a fluid dynamic bearing assembly capable of preventing leakage of lubricating fluid by suppressing interfacial movement of lubricating fluid in a fluid dynamic bearing assembly and a motor including the same.

A hydrodynamic bearing assembly according to an embodiment of the present invention includes a sleeve rotatably supporting a shaft; A thrust plate provided on the shaft to face an upper surface of the sleeve; A cap member disposed on the thrust plate and configured to seal a lubricating fluid between the thrust plate and the thrust plate; And a pressure reducing part formed on an upper surface of the thrust plate to suppress an interface movement of the lubricating fluid.

The pressure reducing portion of the hydrodynamic bearing assembly according to an embodiment of the present invention may be formed by recessing in the circumferential direction on the upper surface of the thrust plate.

The hydrodynamic bearing assembly according to an embodiment of the present invention may be formed such that both side ends of the pressure reducing part have an inclined surface.

An angle formed between the inclined surface of the pressure reducing unit and the top surface of the thrust plate of the hydrodynamic bearing assembly according to the exemplary embodiment of the present invention may be 15 ° to 45 °.

A gas-liquid interface of the lubricating fluid may be formed between the lower surface of the cap member and the pressure reducing portion of the hydrodynamic bearing assembly according to an embodiment of the present invention.

A motor according to an embodiment of the present invention includes a fluid dynamic pressure bearing assembly; A stator coupled to the cap member and having a core wound around a coil for generating a rotational driving force; And a rotor fixed to the shaft so as to be rotatable with respect to the stator and having a magnet facing the core.

According to the fluid dynamic bearing assembly and the motor including the same according to an embodiment of the present invention, it is possible to prevent the leakage of the lubricating fluid by suppressing the interfacial movement of the lubricating fluid formed between the thrust plate and the cap member. It can improve performance.

1 is a schematic cross-sectional view of a motor including a hydrodynamic bearing assembly in accordance with an embodiment of the present invention.
2 is an enlarged cross-sectional view of portion A of FIG. 1;
3 is a perspective view of a thrust plate according to an embodiment of the present invention.
4 is a partial cross-sectional view of a fluid dynamic bearing assembly according to another embodiment of the present invention.

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 of a motor including a hydrodynamic bearing assembly according to one embodiment of the present invention.

Referring to FIG. 1, the motor 400 according to the first embodiment of the present invention may include a fluid dynamic bearing assembly 100, a rotor 200, and a stator 300.

First, when defining the term for the direction, the axial direction refers to the up and down direction relative to the shaft 110, as shown in Figure 1, the radial outward or inward direction relative to the shaft (110) relative to the rotor ( The center direction of the shaft 110 refers to the outer end direction of the 200 or the outer end of the rotor 200.

The stator 300 may include a coil 320, a core 330, and a base member 310.

The stator 300 is a fixed structure including a core 330 to which a coil 320 for generating a predetermined magnitude of electromagnetic force when power is applied.

The core 330 is fixedly disposed on an upper portion of the base member 310 provided with a printed circuit board (not shown) on which a pattern circuit is printed, and a base corresponding to the core 330 on which the coil 320 is wound. A plurality of coil holes having a predetermined size may be formed in the upper surface of the member 310 to expose the coil 320 downward, and the coil 320 may be provided with an external power supply to the printed circuit board (not shown). Is electrically connected to the

The rotor 200 is a rotating structure rotatably provided with respect to the stator 300. The rotor 200 includes a rotor 300 having a ring-shaped magnet 220 on its outer circumferential surface, (Not shown).

Here, the rotor case 210 extends in the outer diameter direction from the hub base 212 and the hub base 212 to be pressed and fixed to the upper end of the shaft 110 and bent downward in the axial direction the magnet 220 It may be made of a magnet support 214 for supporting.

The magnet 220 is provided as a permanent magnet which alternately magnetizes N and S poles in a circumferential direction to generate magnetic force of a predetermined intensity.

Looking briefly about the rotational drive of the rotor 200, when power is supplied to the coil 320 wound on the core 330, the magnet 220 and the core 330 wound around the coil 320 The electromagnetic force with which the rotor 200 is rotated generates a driving force.

Accordingly, the rotor 200 is rotated, and the shaft 110 to which the rotor 200 is fixedly coupled rotates with the rotor 200.

FIG. 2 is an enlarged cross-sectional view of portion A of FIG. 1, and FIG. 3 is a perspective view of a thrust plate according to an embodiment of the present invention.

2 and 3, the hydrodynamic bearing assembly 100 according to the first embodiment of the present invention includes a shaft 110, a sleeve 120, a thrust plate 130, a cover plate 160, and a cap member. 140 may be included.

The sleeve 120 may support the shaft 110 such that the upper end of the shaft 110 protrudes upward in the axial direction, and forge Cu or Al, or sinter Cu-Fe alloy powder or SUS powder. Can be formed.

Here, the shaft 110 is inserted to have a micro gap with the shaft hole of the sleeve 120, the micro gap is filled with lubricating fluid, at least of the outer diameter of the shaft 110 and the inner diameter of the sleeve 120 The radial dynamic pressure groove (not shown) formed in one may support the rotation of the shaft 110 more smoothly.

The radial dynamic pressure groove may be formed on the inner circumferential surface of the sleeve 120 that is inside the shaft hole of the sleeve 120, the shaft 110 is the inner circumferential surface of the sleeve 120 when the shaft 110 is rotated Pressure is formed so as to rotate smoothly and spaced apart from each other.

However, the radial dynamic pressure groove (not shown) is not limited to being provided on the inner circumferential surface of the sleeve 120 as mentioned above, and may be provided on the outer circumferential surface of the shaft 110, and the number is not limited. Let's find out.

The radial dynamic pressure groove (not shown) may be any one of a herringbone shape, a spiral shape, and a screw shape, and the shape may be any shape as long as it generates a radial dynamic pressure.

The sleeve 120 includes a bypass channel 125 formed to communicate the upper and lower portions of the sleeve 120 to maintain an equilibrium by dispersing the pressure of the lubricating fluid in the fluid dynamic bearing assembly 100. It may be possible, and can be moved to discharge the bubbles and the like existing in the fluid dynamic bearing assembly 100 by circulation.

Here, the cover plate 150 may be coupled to the lower portion of the sleeve 120 to be coupled to the sleeve 120 while maintaining a gap, and to accommodate the lubricating fluid.

The cover plate 150 may serve as a bearing for supporting a lower surface of the shaft 110 by receiving a lubricating fluid in a gap formed between the sleeve 120 and itself.

The cap member 140 is a member to seal the lubricating fluid between the thrust plate 130 to be described later, the cap member 140 may have a disk shape having a ring shape as a whole.

The cap member 140 may have a protrusion 142 formed on a lower surface of the cap member 140 to seal the lubricating fluid. The cap member 140 uses a capillary phenomenon to prevent the lubricating fluid from leaking to the outside when the motor is driven.

In addition, the cap member 140 may be disposed to face the top surface of the thrust plate 130, the cap member 140 is opposed to the top surface of the thrust plate 130 in order to seal the lubricating fluid between the thrust plate 130 The lower surface of the cap member 140 may be provided in a tapered shape.

This uses capillary action and surface tension of the lubricating fluid to prevent leakage of the lubricating fluid to the outside when the motor is driven.

The cap member 140 may have a diameter of an inner circumferential surface in contact with the base member 310 greater than a diameter of an inner circumferential surface in contact with the outer circumferential surface of the thrust plate 130 so as to be seated on the axially upper side of the sleeve 120.

This is to match the outer circumferential surface of the cap member 140 and the outer circumferential surface of the base member 310 in parallel. As a result, the outer circumferential surface of the cap member 140 and the core 210 around which the coil 220 is wound This is to stably press-fit the outer circumferential surface of the base member 310.

Therefore, the shape of the base member 310 also has an outer circumferential surface with a difference in diameter corresponding to the shape of the cap member 140.

In this case, the cap member 140 is press-fitted to the outer circumferential surface of the base member 310 results in the diameter of the sleeve 120 can be substantially reduced.

This relatively reduces the inner diameter of the core 330 pressed into the base member 310, and naturally increases the length of the core 330 teeth to which the coil 320 is wound.

Therefore, the number of turns of the coil 320 wound around the core 330 may be increased, thereby improving performance and dynamic stability of the hydrodynamic bearing assembly 100.

The thrust plate 130 is disposed in the upper axial direction of the sleeve 120, and has a hole corresponding to the cross section of the shaft 110 in the center, the shaft 110 can be inserted into the hole. .

In this case, the thrust plate 130 may be manufactured separately and may be combined with the shaft 110, but may be formed integrally with the shaft 110 from the time of manufacture, and the shaft during the rotational movement of the shaft 110. Rotational movement along 110.

In addition, a thrust dynamic pressure groove for providing a thrust dynamic pressure to the shaft 110 may be formed on an upper surface of the thrust plate 130.

As described above, the thrust dynamic pressure groove is not limited to the upper surface of the thrust plate 130, but may be formed on one surface of the cap member 140 corresponding to the upper surface of the thrust plate 130. .

A gas-liquid interface of the lubricating fluid may be formed between a lower surface of the cap member 140 and an upper surface of the thrust plate 130. Specifically, the gas-liquid interface of the lubricating fluid may include a pressure reducing unit 135 and the following. It may be formed between the lower surface of the cap member 140.

A pressure reducing unit 135 may be formed on the upper surface of the thrust plate 130 to suppress the interface movement of the lubricating fluid.

Specifically, the pressure reducing unit 135 may be formed by recessing in the circumferential direction on the upper surface of the thrust plate 130, and both side ends of the pressure reducing unit 135 may be formed to have an inclined surface.

Due to the strong relative movement between the cap member 140 and the thrust plate 130, the lubricating fluid may be formed in a narrow flow path formed between the protrusion 142 of the cap member 140 and the upper surface of the thrust plate 130. The pressure rises, which risks leakage of the lubricating fluid beyond the surface tension at the interface of the lubricating fluid.

In particular, the leakage of lubricating fluid is a high risk when the interface of the lubricating fluid retracts radially outward and then rises radially inward again, which is instantaneous when the interface of the lubricating fluid retreats and then rises again. This is because strong energy is generated by dissipating energy.

In order to overcome this, a large amount of lubricating fluid must be present between the cap member 140 and the thrust plate 130 so that the interface retreat of the lubricating fluid can be minimized.

A large amount of lubricating fluid may be stored between the pressure reducing unit 135 formed on the upper surface of the thrust plate 130 and the lower surface of the cap member 140. Interfacial movement of the fluid can be suppressed.

The pressure reducing part 135 is recessed in the circumferential direction on the upper surface of the thrust plate 130, and both side ends of the pressure reducing part 135 are formed to have an inclined surface to prevent leakage of the lubricating fluid. Can be.

That is, the lubrication fluid by rapidly reducing the pressure of the lubricating fluid is formed by forming a space that extends widely through the narrow passage formed between the protrusion 142 of the cap member 140 and the top surface of the thrust plate 130. To prevent leakage of fluid.

Here, an angle formed between the inclined surfaces formed at both side ends of the pressure reducing unit 135 and the upper surface of the thrust plate 130 may be 15 ° to 45 °.

When the value of the angle is smaller than 15 °, the effect of stabilizing the interface of the lubricating fluid is insufficient, and when the value of the angle is greater than 45 °, the pressure reducing portion when the interface of the lubricating fluid retreats radially outward. This is because bubbles may be generated at points where the inclined surfaces formed at both side ends of the 135 meet the upper surface of the thrust plate 130.

4 is a partial cross-sectional view of a fluid dynamic bearing assembly according to another embodiment of the present invention.

Referring to FIG. 4, the fluid dynamic bearing assembly 100 according to another embodiment of the present invention is described with reference to FIGS. 1 to 3 except for the pressure reducing unit 135 formed on the thrust plate 130. Since it is the same as the hydrodynamic bearing assembly 100, descriptions other than the pressure reducing unit 135 will be omitted.

The pressure reducing unit 135 may be stepped in an inclined direction in an inner diameter direction at a predetermined position at an outer end of the thrust plate 130.

That is, the thickness of the outer side and the inner side of the thrust plate 130 may be different.

A gas-liquid interface of lubricating fluid may be formed between the pressure reducing unit 135 and the lower surface of the cap member 140.

In the above description of the configuration and features of the present invention based on the embodiment according to the present invention, the present invention is not limited thereto, and various changes or modifications can be made within the spirit and scope of the present invention. It will be apparent to those skilled in the art that such changes or modifications fall within the scope of the appended claims.

100: hydrodynamic bearing assembly 110: shaft
120: Sleeve 130: Thrust plate
140: cap member 150: cover plate
200: rotor 210: rotor case
220: Magnet 300: Stator
310: base member 320: coil
330: Core

Claims (6)

A sleeve for rotatably supporting the shaft;
A thrust plate provided on the shaft to face an upper surface of the sleeve;
A cap member disposed on the thrust plate and configured to seal a lubricating fluid between the thrust plate and the thrust plate; And
And a pressure reducing part formed on an upper surface of the thrust plate to suppress an interface movement of the lubricating fluid.
The method of claim 1,
The pressure reducing part is a fluid dynamic bearing assembly formed by recessing in the circumferential direction from the upper surface of the thrust plate.
The method of claim 2,
Both side ends of the pressure reducing portion is formed with a fluid dynamic bearing assembly.
The method of claim 3,
And an angle formed between the inclined surface of the pressure reducing unit and the upper surface of the thrust plate is 15 ° to 45 °.
The method of claim 2,
And a gas-liquid interface of the lubricating fluid is formed between the lower surface of the cap member and the pressure reducing portion.
A fluid dynamic bearing assembly according to any one of claims 1 to 4;
A stator coupled to the cap member and having a core wound around a coil for generating a rotational driving force; And
And a rotor fixed to the shaft so as to be rotatable with respect to the stator and having a magnet facing the core.
KR1020110141638A 2011-12-23 2011-12-23 Hydrodynamic bearing assembly and motor including the same KR20130073672A (en)

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KR1020110141638A KR20130073672A (en) 2011-12-23 2011-12-23 Hydrodynamic bearing assembly and motor including the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110141638A KR20130073672A (en) 2011-12-23 2011-12-23 Hydrodynamic bearing assembly and motor including the same

Publications (1)

Publication Number Publication Date
KR20130073672A true KR20130073672A (en) 2013-07-03

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102199452B1 (en) 2019-10-17 2021-01-06 안지훈 Leftovers collection apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102199452B1 (en) 2019-10-17 2021-01-06 안지훈 Leftovers collection apparatus

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