KR101133373B1 - spindle motor and disk driver having the same - Google Patents

Abstract

The present invention relates to a spindle motor and a disk driver having the same. The spindle motor according to the present invention includes a sleeve rotatably supporting a shaft, a bush coupled to an upper portion of the shaft to rotate together with the shaft, and an outer circumferential surface of the bush. A rotor case having a cylindrical wall portion coupled to the rotor, the rotor case being formed in an axially lower portion of the bush and radiating airflow generated between the shaft and the sleeve when the shaft rotates, from the shaft to the outer circumferential surface of the bush; And an airflow diverging portion, and a sealing portion formed under the axial direction of the bush and formed between the cylindrical wall portion and the airflow diverging portion to seal oil when the shaft rotates.

Description

Spindle motor and disk driver having same {spindle motor and disk driver having the same}

The present invention relates to a spindle motor and a disk driver having the same, and more particularly, to adjust the structure of a bush coupled to an outer circumferential surface of a shaft, thereby preventing a turbulence of air flow generated when the shaft rotates and preventing oil leakage. It's about a motor.

An apparatus for driving an optical disc-type recording medium is a device configured to move an optical pickup device while reading and writing a signal while loading and rotating a recording medium.

The optical disk driver uses a slim drive set (12.7mm), an ultra slim drive set (9.5mm), and a super ultra slim drive set (7.0mm) depending on the thickness. In type is used.

As described above, downsizing is also required for a spindle motor that loads and rotates a recording medium according to the slimming of the optical disk driver. To this end, it is necessary to reduce the axial length of components of the spindle motor.

In particular, due to the necessity of making the thickness of the rotating member thin, there is a problem in the assembly process of the rotating member, and there is a problem that the rotation characteristics are deteriorated, such as vertical vibration or bending vibration.

In addition, since the axial gap between the rotating member and the fixing member of the spindle motor becomes small, there is a problem that airflow turbulence occurs between the rotating member and the fixing member when the rotating member is rotated, and thus the noise and vibration levels are increased.

These airflow turbulences cause unstable behavior of the spindle motor and cause the oil to leak out of the bearing member during rotation. In addition, the unstable behavior of the spindle motor generates a lot of heat in the fixing member, and may cause a problem of lowering the efficiency of the spindle motor and increasing power consumption.

Accordingly, the present invention is to solve the above problems of the prior art, to provide a spindle motor and a disk driver having a rigidity reinforced to secure assembly stability and rotational stability while reducing the size, especially thickness of the device Has its purpose.

In addition, another object of the present invention is to secure a sufficient axial gap between the rotating member and the fixing member with ultra-thin device, inducing a stable flow of air flow generated when the rotating member is rotated, thus noise and vibration during rotation It is to suppress the occurrence of.

In addition, another object of the present invention is to stabilize the operation of the device to prevent oil leakage and reduce power consumption.

Spindle motor according to an embodiment of the present invention for achieving the above technical problem, the sleeve rotatably supporting the shaft, the bush coupled to the upper portion of the shaft to rotate with the shaft, coupled to the outer peripheral surface of the bush Rotor case including a cylindrical wall portion, formed in the axial lower portion of the bush and the air flow divergence that radiates the air flow generated between the shaft and the sleeve when the shaft rotates from the shaft to the radially outward direction of the outer peripheral surface of the bush And a sealing portion formed at an axial lower portion of the bush and formed between the cylindrical wall portion and the airflow diverging portion to seal oil when the shaft rotates.

In addition, in the spindle motor according to an embodiment of the present invention, the air flow diverging portion may be formed such that an axial gap between the upper surface of the sleeve increases toward the radially outer side.

In addition, in the spindle motor according to an embodiment of the present invention, the air flow diverging portion may be formed to be inclined upward toward the radially outer side of the bush.

In addition, in the spindle motor according to an embodiment of the present invention, the annular groove portion may be formed in the lower portion of the bush by the air flow diverging portion and the sealing portion. At this time, the annular groove portion may be formed inclined at least one side wall of both side walls.

In addition, in the spindle motor according to an embodiment of the present invention, the outer diameter of the air flow diverging portion may be formed to be the same as the outer diameter of the sleeve.

In addition, in the spindle motor according to an embodiment of the present invention, the sealing portion may be formed to be inclined downward toward the inner circumferential surface of the cylindrical wall portion from the radially outer side of the air flow diverging portion.

In addition, the spindle motor according to an embodiment of the present invention may further include a taper portion formed in the lower axial direction of the bush and formed between the outer circumferential surface of the shaft and the airflow diverging portion.

In addition, in the spindle motor according to an embodiment of the present invention, the tapered portion may be formed to be inclined downward toward the outer circumferential surface of the shaft from the radially inner side of the air flow diverging portion.

On the other hand, the spindle motor according to another embodiment of the present invention is formed in the sleeve rotatably supporting the shaft, the bush coupled to the upper portion of the shaft to rotate with the shaft, and the axial lower portion of the bush, It may include a groove portion including a first inclined surface is formed to be inclined upward toward the radially outward and a second inclined surface is inclined downward toward the radially outward from the first inclined surface.

In addition, in the spindle motor according to another embodiment of the present invention, the first inclined surface may be formed to be inclined more gently than the second inclined surface.

In another aspect, a disk driver according to an embodiment of the present invention is a rotor case coupled to the upper portion of the shaft and the rotation with the shaft, a rotor case including a cylindrical wall fixed to the outer peripheral surface of the bush and the inner of the rotor case A rotor including a magnet mounted to the rotor, a chucking portion mounted to the rotor case to detachably couple a disk, a sleeve rotatably supporting the shaft, a holder supporting the sleeve, and a magnetic material interacting with the magnet. A stator including an airflow diverging portion formed at an axially lower portion of the bush and dissipating airflow generated between the shaft and the sleeve when the shaft rotates from the shaft to a radially outer side in the outer circumferential direction of the bush; It is formed in the lower axial direction of the bush when the shaft rotates To seal the work may include a seal formed between the cylindrical wall and the air stream diverging portion.

Further, in the disk driver according to an embodiment of the present invention, the air flow diverging portion may be formed to be inclined upwardly so that the axial gap between the upper surface of the sleeve and the greater the radially outward.

In addition, in the disk driver according to an embodiment of the present invention, an annular groove portion is formed in the lower portion of the bush by the airflow diverging portion and the sealing portion, and at least one sidewall of both side walls of the annular groove portion is formed to be inclined. Can be.

Further, in the disk driver according to an embodiment of the present invention, the outer diameter of the air flow diverging portion may be formed to be the same as the outer diameter of the sleeve.

In addition, in the disk driver according to an embodiment of the present invention, the sealing portion may be formed to be inclined downward toward the inner circumferential surface of the cylindrical wall portion from the radially outer side of the airflow diverging portion.

According to the spindle motor and the disk driver having the same according to the present invention, the axial gap between the rotating member and the fixing member is sufficiently secured by changing the structure of the bush coupled to the shaft, so that the rotating member is reduced according to the ultra-thin spindle motor. By reducing the turbulence of the airflow generated during rotation, it is possible to secure rotational stability, such as the occurrence of noise and vibration during rotation.

In addition, according to the present invention, by forming a sealing portion in the lower portion of the bush, it is possible to prevent the leakage of oil coming out of the sleeve during high-speed rotation of the spindle motor.

In addition, according to the present invention, by providing a configuration for reinforcing the rigidity of the spindle motor, it is possible to prevent the degradation of the rigidity due to the ultra-thin of the spindle motor, thereby ensuring the assembly and rotational stability.

In addition, according to the improvement of the characteristics of the spindle motor, it is possible to effectively reduce the power consumed for the assembly and rotational drive of the spindle motor.

1 is an axial sectional view of a disk driver according to a first embodiment of the present invention.
FIG. 2 is an enlarged view of a portion A of FIG. 1.
3 is a plan view, an axial sectional view, and a bottom view showing a bush in the spindle motor according to the first embodiment of the present invention.
4 is an upward perspective view of a bush in the spindle motor according to the first embodiment of the present invention.
5 is a plan view, an axial sectional view, and a bottom view showing a bush in the spindle motor according to the second embodiment of the present invention.
6 is an upward perspective view of a bush in the spindle motor according to the second embodiment of the present invention.
7 is a plan view, an axial sectional view and a bottom view of the bush in the spindle motor according to the third embodiment of the present invention.
8 is an upward perspective view of a bush in the spindle motor according to the third embodiment of the present invention.

Hereinafter, with reference to the drawings will be described in detail a specific embodiment of the present invention. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention may further deteriorate other inventions or the present invention by adding, changing, or deleting other elements within the scope of the same idea. Other embodiments included within the scope of the invention can be easily proposed, but it will also be included within the scope of the invention.

In addition, the component with the same function within the range of the same idea shown by the figure of each embodiment is demonstrated using the same or similar reference numeral.

1 is an axial cross-sectional view of a disk driver according to a first embodiment of the present invention, FIG. 2 is an enlarged view of portion "A" of FIG. 1, and FIG. 3 is a plan view, an axial cross-sectional view and a bottom view of the bush. 4 is an upward perspective view of the bush.

1 and 2, the disk driver 100 according to the first embodiment of the present invention includes the spindle motor assemblies 10, 20, and 30, the rotor assembly 40, and the stator assembly 50, which are rotating shafts. And chucking unit 60 may include.

The spindle motor assembly may include a shaft 10, a bush 30 coupled to an outer circumferential surface of the shaft 10 to rotate together with the shaft 10, and a bearing portion 20 rotatably supporting the shaft 10. Can be.

 The shaft 10 may be disposed on the same axis as a predetermined central axis and rotate about a virtual rotation axis when the spindle motor rotates.

The bearing portion 20 is a cylindrical sleeve 21 which supports the shaft 10 in a radially free manner, and a thrust washer disposed below the sleeve 21 and rotatably supporting the shaft 10 in an axial direction. And a cover plate 23 covering the lower portion of the sleeve 21 and the thrust washer 22.

Here, when the direction is defined, the axial direction refers to the direction parallel to the central axis of the shaft 10, and is divided into upper and lower, and the radial direction refers to the direction perpendicular to the axial direction, the inner and outer The circumferential direction refers to the direction along the circumference of the circle.

The sleeve 21 may include an axially penetrating through hole in which the shaft 10 is inserted, and may be made of a sintered-containing material sintered by containing lubricating oil such as oil. The journal bearing may be formed between the outer circumferential surface of the shaft 10 and the inner circumferential surface of the sleeve 21 to radially support the rotation of the shaft 10.

In addition, at least one of the outer circumferential surface of the shaft 10 and the inner circumferential surface of the sleeve 21 may be formed with a dynamic pressure groove to maintain a constant pressure of oil in the journal bearing when the shaft 10 rotates.

The thrust washer 22 is disposed in the lower axial direction of the shaft 10 and can be inserted and fixed in the central groove of the cover plate 23. A thrust bearing may be formed between the thrust washer 22 and the shaft 10 to support the rotation of the shaft 10 in the axial direction.

3 and 4, the bush 30 has a body portion 31 coupled to the upper outer circumferential surface of the shaft 10, an air flow diverging portion 32 and a sealing portion formed under the body 31. 33), the shaft 10 may include a hollow portion 34 penetrating the body portion 31 in the axial direction.

The airflow diverging portion 32 may be formed to be inclined upwardly toward the radially outer side such that an axial gap G between the lower portion of the bush 30 and the upper surface of the sleeve 21 becomes larger toward the radially outer side. That is, the outer diameter side axial gap G2 of the bush 30 may be formed larger than the inner diameter side axial gap G1 of the bush 31.

This makes it possible to prevent the airflow generated between the shaft and the sleeve from being unstable when the spindle motor rotates due to the thinning of the spindle motor. That is, when the spindle motor rotates, the airflow generated between the shaft 10 and the sleeve 21 moves along the airflow diverging portion 32, and since the axial gap becomes larger, the air flows toward the radially outer side. The pressure is lowered to show stable behavior.

The airflow emitted from the airflow diverging portion 32 moves along the sealing portion 33 and exits out of the stator 50.

The airflow diverging part 32 may form a part of the annular groove formed in the circumferential direction at the bottom of the cylindrical bush 30, and at least one surface of the groove may be inclined. The radial length of the airflow divergence 32 may be formed substantially the same as the radial length of the sleeve 21. That is, the outer diameter of the airflow diverging portion 32 may be formed to match the outer diameter of the sleeve 21.

The sealing portion 33 is a cylindrical wall portion of the rotor case 41 in the radially outer side of the airflow diverging portion 32 so that oil coming out of the sleeve 21 made of a sintered-containing material does not leak according to the high speed rotation of the spindle motor. It extends to the outer peripheral surface of 41a.

The sealing part 33 may be formed to be inclined downward toward the outer side in the radial direction, and not only to prevent oil leakage during rotation of the spindle motor, but also as the thickness of the bush 30 becomes thin due to the thinning of the spindle motor, thereby reducing rigidity. It can also serve as a rigid reinforcement to prevent the damage.

At this time, the sealing portion 33 may form a portion excluding the airflow diverging portion 32 in the groove portion formed along the circumferential direction at the lower portion of the cylindrical bush 30. That is, the airflow diverging portion 32 and the sealing portion 33 may form both inclined surfaces of the groove portion having an axial cross section formed in the circumferential direction under the body 31 in an inverted V shape.

A first inclined surface that is formed to be inclined upward toward the radially outer side of the bush 30 has the airflow diverging portion 32, and a second inclined surface that is formed to be inclined downward from the first inclined surface toward the radially outer side thereof is the sealing portion ( 33) can be configured.

The first inclined surface constituting the airflow diverging portion 32 may be formed more smoothly than the second inclined surface constituting the sealing portion 33. In addition, the axial length of the second inclined surface may be formed longer than the axial length of the first inclined surface.

The shaft 10 may be pressed into the hollow part 34, and an adhesive may be applied between the shaft 10 and the bush 30.

The rotor assembly 40 may include a rotor case 41, a driving magnet 42, and a disk mounting portion 43.

The rotor case 41 has a first cylindrical wall portion 41a protruding upward in the center and coupled to an outer circumferential surface of the bush 30, a disc portion 41b extending radially outward from a lower end of the first cylindrical wall portion 41a, And a second cylindrical wall portion 41c protruding downward from the radially outer end of the disc portion 41b.

The first cylindrical wall portion 41a may be formed by bending the center of the rotor case 41, and an outer circumferential surface of the bush 30 may be coupled to an inner surface of the first cylindrical wall portion 41a.

The disk mounting portion 43 on which the disk 70 is seated may be formed on the upper surface of the disc portion 41b, and the attractive force acts on the lower surface of the stator assembly 50 so that the rotor assembly 40 is stable. Suction magnet 45 is formed to be rotated to the rotation and the stopper 44 is caught on the latch 55 formed on the holder 51 so that the rotating member does not escape to the upper axial direction when the spindle motor rotates. .

An annular drive magnet 42 corresponding to the coil 54 of the stator assembly 50 may be formed on the inner circumferential surface of the second cylindrical wall portion 41c. The suction magnet 45 and the driving magnet 42 are permanent magnets that alternately magnetize the N pole and the S pole in the circumferential direction to generate a magnetic force of a predetermined intensity.

The stator assembly 50 includes a holder 51 coupled to an outer circumferential surface of the sleeve 21 to fix and support the spindle motor assembly, a plurality of cores 53 coupled to an outer circumferential surface of the holder 51, and the plurality of cores ( And coil 53 wound around 53.

A base plate 52 may be coupled to a lower outer circumferential surface of the holder 51, and a circuit board may be provided on an upper portion of the base plate 52 to control the rotational drive of the spindle motor.

The upper outer circumferential surface of the holder 51 may be formed with a latch 55 to which the stopper 44 is caught to prevent the axial pull-out of the rotating member when the spindle motor rotates.

The electromagnetic assembly between the coil 54 and the driving magnet 42 causes the rotor assembly 40 to rotate. Specifically, when electricity is supplied to the coil 54 from the circuit board formed on the base plate 52, the plurality of cores 53 on which the coil 54 is wound is magnetized and faces the plurality of cores 53. The rotor assembly 40 is rotated by electromagnetic interaction with the driving magnet 42.

The chucking unit 60 detachably couples the disk 70 to the spindle motor, and may include an elastic member. When the disc 70 is inserted, the chucking part 60 deforms the elastic member by a force applied to the chucking part 60, retreats inward in the radial direction, and the disc 70 rotates in the rotor case. When seated on the 41, the disk 70 is fixed on the spindle motor by pressing the inner peripheral surface of the disk 70 by the restoring force of the elastic member.

5 is a plan view, an axial sectional view, and a bottom view showing a bush in the spindle motor according to the second embodiment of the present invention, and FIG. 6 is an upward perspective view of the bush.

The spindle motor according to the second embodiment of the present invention shown in FIGS. 5 and 6 shows a modification of the bush, and the other configuration is the spindle according to the first embodiment of the present invention shown in FIGS. Since it is substantially the same as the motor, a detailed description of these configurations will be omitted, and the following description will focus on the differences.

5 and 6, in the spindle motor according to the second embodiment of the present invention, the bush 300 includes a body portion 310, a lower portion 320, and a hollow portion 340, and the lower portion thereof. The taper portion 321, the airflow diverging portion 322, and the sealing portion 323 may be formed at the 320.

The taper portion 321 is formed to be inclined downward toward the inner diameter side of the body portion 310, the airflow diverging portion 322 is formed between the taper portion 321 and the sealing portion 323, the sealing portion 323 is the body It may be inclined downward toward the outer diameter side of the part 310.

The lower portion 320 of the bush 300 may have a shape of an annular groove formed in the circumferential direction, in which the taper portion 321 forms one side wall of the groove portion, and the airflow diverging portion 322 is the bottom surface of the groove portion. To achieve this, the sealing portion 323 may form the other side wall of the groove portion.

At this time, both sidewalls of the groove portion may be formed to be inclined toward the inner diameter side and the outer diameter side of the bush 300, respectively, the axial length of both sidewalls sidewalls constituting the sealing portion 323 sidewalls of the tapered portion 321 It can be formed longer.

The tapered portion 321 may serve to reinforce the rigidity of the bush 300 is thinned according to the thinning of the spindle motor, the air flow generated between the shaft and the sleeve is moved to the air flow diverging portion 322 Can be facilitated.

In the present embodiment, the air flow diverging portion 322 is shown and described to be formed parallel to the radial direction, the present invention is not limited to this, the air flow diverging portion 322 may be formed to be inclined toward the radially outer side. have.

7 is a plan view, an axial sectional view, and a bottom view showing a bush in the spindle motor according to the third embodiment of the present invention, and FIG. 8 is an upward perspective view of the bush.

The spindle motor according to the third embodiment of the present invention shown in Figures 7 and 8 shows a modification of the bush, the other configuration is the spindle according to the first embodiment of the present invention shown in Figures 1 to 4 Since it is substantially the same as the motor, a detailed description of these configurations will be omitted, and the following description will focus on the differences.

7 and 8, in the spindle motor according to the third embodiment of the present invention, the bush 500 includes a body portion 510, a lower portion 520, and a hollow portion 540, and the lower portion The airflow diverging portion 522 and the sealing portion 523 may be formed at 520.

The sealing part 523 may be tapered toward the outer circumferential surface of the bush 500.

The airflow diverging part 522 may be stepped toward the radially outer side, and may include a first step part 522a and a second step part 522b.

The second step portion 522b is formed radially outward of the first step portion 522a, and an axial gap of the second step portion 522b is between the sleeve and the axial direction of the first step portion 522a. It may be formed larger than the gap.

The lower portion 320 of the bush 300 may have a shape of an annular groove formed in the circumferential direction, the groove portion may be formed of an outer wall and a bottom portion, the bottom portion of the airflow diverging portion 522, and the outer wall of the sealing portion 523. Can be configured. In this case, the bottom portion may be formed stepped to form the first step portion 522a and the second step portion 522b.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. For example, the components of the spindle motor assembly in the present invention are merely illustrated and may have various shapes, in particular, the thrust washer may have a U shape and the cover plate may be a substantially circular flat plate. Accordingly, the true scope of the present invention should be determined by the appended claims.

100: disk driver
10: shaft 20: bearing part
30, 330, 530: bush 40: rotor assembly
50: stator assembly 60: chucking portion
70: disc

Claims (16)

A sleeve rotatably supporting the shaft;
A bush coupled to an upper portion of the shaft and rotating together with the shaft;
A rotor case including a cylindrical wall portion coupled to an outer circumferential surface of the bush;
An air flow diverging portion formed at an axial lower portion of the bush and dissipating air flow generated between the shaft and the sleeve when the shaft rotates from the shaft to a radially outer side in the direction of the outer circumferential surface of the bush; And
A sealing portion formed in an axial lower portion of the bush and formed between the cylindrical wall portion and the air flow diverging portion to seal oil when the shaft rotates;
Spindle motor comprising a.
The method of claim 1,
And the airflow diverging portion is formed such that an axial gap between the upper surface of the sleeve and the radially outer side becomes larger.
The method of claim 1,
And the airflow diverging portion is formed to be inclined upward toward the radially outer side of the bush.
The method of claim 1,
Spindle motor, characterized in that the annular groove portion is formed in the lower portion of the bush by the air flow diverging portion and the sealing portion.
The method of claim 4, wherein
The annular groove portion is a spindle motor, characterized in that at least one side wall of both side walls are formed to be inclined.
The method of claim 1,
The outer diameter of the air flow diverging portion is formed in the spindle motor, characterized in that the same as the outer diameter of the sleeve.
The method of claim 1,
And said sealing portion is inclined downward toward the inner circumferential surface of said cylindrical wall portion from the radially outer side of said airflow diverging portion.
The method of claim 1,
And a taper formed at an axial lower portion of the bush and formed between an outer circumferential surface of the shaft and the airflow diverging portion.
The method of claim 8,
And the taper portion is inclined downward toward the outer circumferential surface of the shaft from the radially inner side of the airflow diverging portion.
A sleeve rotatably supporting the shaft;
A bush coupled to an upper portion of the shaft and rotating together with the shaft; And
A groove portion formed in an axial lower portion of the bush and including a first inclined surface that is formed to be inclined upward toward a radially outer side of the bush and a second inclined surface that is inclined downward from the first inclined surface to a radially outer side thereof;
Spindle motor comprising a.
The method of claim 10,
The first inclined surface of the spindle motor, characterized in that the inclination is formed more gentle than the second inclined surface.
A bush coupled to an upper portion of the shaft and rotating together with the shaft;
A rotor including a rotor case fixed to an outer circumferential surface of the bush, and a magnet mounted inside the rotor case;
A chucking unit mounted to the rotor case to detachably couple a disk;
A sleeve rotatably supporting the shaft;
A stator including a holder supporting the sleeve and a magnetic material interacting with the magnet;
An air flow diverging portion formed at an axial lower portion of the bush and dissipating air flow generated between the shaft and the sleeve when the shaft rotates from the shaft to a radially outer side in the direction of the outer circumferential surface of the bush; And
A sealing portion formed in an axial lower portion of the bush and formed between the cylindrical wall portion and the air flow diverging portion to seal oil when the shaft rotates;
Disk driver including.
The method of claim 12,
And the airflow diverging portion is formed to be inclined upwardly so that an axial gap between the upper surface of the sleeve and the radially outer side becomes larger.
The method of claim 12,
And an annular groove formed under the bush by the air flow diverging portion and the sealing portion, and at least one sidewall of both side walls of the annular groove portion is inclined.
The method of claim 12,
The outer diameter of the air flow diverging portion is formed to be the same as the outer diameter of the sleeve.
The method of claim 12,
And the sealing portion is formed to be inclined downward toward the inner circumferential surface of the cylindrical wall portion from the radially outer side of the airflow diverging portion.

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