KR20140055504A - Spindle motor - Google Patents

Abstract

A spindle motor according to the present invention includes: a rotation unit including a sleeve, a hub coupled to the sleeve, and a magnet coupled to the inner peripheral surface of the hub; and a fixing unit including a shaft supporting the sleeve to enable the sleeve to rotate, a holder rigidly coupled to the shaft, a base coupled to the holder, and an armature which is coupled to the outer peripheral area of the base to face the magnet. A dynamic fluid pressure bearing unit is formed between the rotation unit and the fixing unit by injecting the oil used as a working fluid, and an oil sealing unit is formed on a facing unit of the hub integrated with the sleeve and the shaft. The shaft faces the oil sealing unit to form oil injection holes.

Description

[0001] SPINDLE MOTOR [0002]

The present invention relates to a spindle motor.

2. Description of the Related Art Generally, a spindle motor used as a drive device for a recording disk, such as a hard disk, stores a lubricant such as oil between a rotating portion and a fixed portion at the time of rotation of a motor, It is widely used.

More specifically, a spindle motor equipped with a fluid dynamic pressure bearing that maintains axial rigidity of the shaft only by the moving pressure of the lubricating oil by centrifugal force is based on the thrust force. Therefore, there is no metal friction, And it is mainly applied to high-end optical disc apparatuses and magnetic disc apparatuses, since the high-speed rotation of the rotating object is smoother than the motor having the ball bearing.

The spindle motor according to the prior art, which includes the prior art documents, has a problem in that the oil injected for forming the hydrodynamic pressure bearing is evaporated to the outside and the motor life is shortened Not only unstable motor driving is caused but also oil control and injection are difficult.

Patent Document 1: Korean Patent No. 10-0200598

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide an oil injection hole for an oil pump which is easy to inject and interface with, And a part of the sleeve-integrated hub is supported by the cover part, so that the shake is prevented by the external impact and the spindle motor is more firmly realized. In addition, the stiffness of the spindle motor is increased as the thickness of the upper sealing portion of the shaft is increased. As a result, the shaft includes the function of the cap portion, so that the spindle motor can be realized more efficiently and simpler without including a separate cap or cover, and also provides a stiffer and more stable spindle motor.

A spindle motor according to an embodiment of the present invention includes a sleeve, a hub coupled to the sleeve, a rotating portion including a magnet coupled to an inner circumferential surface of the hub, a shaft rotatably supporting the sleeve, And a fixing part including a coupled holder, a base coupled with the holder, and an armature coupled to an outer periphery of the base so as to be opposed to the magnet, wherein oil as a working fluid is injected, An oil sealing portion is formed at an opposite portion of the shaft and the sleeve-integrated hub, and the shaft is opposed to the oil sealing portion to form an oil injection hole.

In addition, the sleeve and the hub of the spindle motor according to an embodiment of the present invention may be formed of a sleeve-integrated hub integrally formed therewith.

Further, the sleeve-integrated hub of the spindle motor according to an embodiment of the present invention includes a sleeve portion facing the shaft and formed in a cylindrical shape, a disk portion extending radially outward from the sleeve portion, and a radially outer side And a side wall portion extending downward in the axial direction of the shaft at the end portion.

The sleeve portion of the spindle motor according to an embodiment of the present invention is formed with an upper sealing portion on an upper portion in an axial direction of a shaft for oil sealing and a lower sealing portion on a lower portion.

In addition, the upper sealing portion and the lower sealing portion of the spindle motor according to an embodiment of the present invention may be tapered.

Further, the shaft of the spindle motor according to an embodiment of the present invention is formed such that the upper sealing portion for sealing is opposed to the upper sealing portion of the sleeve.

Further, the shaft of the spindle motor according to an embodiment of the present invention may further include a cap portion extending to the upper sealing portion and positioned above the upper sealing portion of the sleeve-integrated hub.

Further, the cap portion of the shaft of the spindle motor according to the embodiment of the present invention is formed with an oil injection hole.

In addition, the oil injection hole of the spindle motor according to the embodiment of the present invention may be formed such that the oil injection hole is wide and the oil discharge hole is narrow.

Further, the upper sealing portion of the shaft of the spindle motor according to an embodiment of the present invention may further include a cover portion surrounding at least a part of the sleeve-integrated hub.

Further, the cover portion of the spindle motor according to an embodiment of the present invention may be formed to surround the upper sealing portion of the sleeve-integrated hub.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to that, terms and words used in the present specification and claims should not be construed in a conventional and dictionary sense, and the inventor may properly define the concept of the term in order to best explain its invention It should be construed as meaning and concept consistent with the technical idea of the present invention.

According to the present invention, an oil injection hole is formed in the shaft to facilitate oil injection and interface maintenance, oil leakage is prevented by the cap portion, and a part of the sleeve-integrated hub is supported by the cover portion, So that the spindle motor is more robustly realized. In addition, the stiffness of the spindle motor is increased as the thickness of the upper sealing portion of the shaft is increased. As a result, since the shaft includes the function of the cap portion, it is possible to provide a spindle motor that is more efficient and simple as well as more rigid and increased in stability without including a separate cap or cover.

1 is a cross-sectional view schematically showing a spindle motor according to a first embodiment of the present invention.
2 is a cross-sectional view schematically showing a spindle motor according to a second embodiment of the present invention;
FIG. 3 is a partial cross-sectional view schematically showing a cap portion of a shaft according to another embodiment of the spindle motor according to the first and second embodiments shown in FIGS. 1 and 2 of the present invention. FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The objectives, specific advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. It will be further understood that terms such as " first, "" second," " one side, "" other," and the like are used to distinguish one element from another, no. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of the present invention, detailed description of related arts which may unnecessarily obscure the gist of the present invention will be omitted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a sealing module of a fluid dynamic pressure bearing and a spindle motor including the sealing module according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing a spindle motor according to a first embodiment of the present invention.

The spindle motor 100 includes a fixed portion including a shaft 110, a holder 120, a base 130, an armature 140 composed of a core 141 and a coil 142, The hydraulic fluid pressure bearing is formed between the rotary part and the fixed part by filling the working fluid with the oil. The shaft 110 and the sleeve-integrated hub 150 , And the shaft is opposed to the oil sealing portion to form an oil injection hole.

The sleeve-integrated hub 150 is rotatably supported by the shaft 120. The inner diameter of the sleeve-integrated hub 150 is larger than the diameter of the outer diameter of the shaft 110, And the radial dynamic pressure bearing portion is filled with oil at the minute intervals. To this end, a dynamic pressure generating groove is optionally formed in the inner diameter portion of the sleeve or the outer diameter portion of the shaft.

The sleeve-integrated hub 150 includes a sleeve 151 which is opposed to the shaft and has a cylindrical shape, a disk 152 extending radially outward from the sleeve 151, And a side wall portion 153 extending downward in the axial direction of the shaft at the radially outer end portion.

The sleeve 151 is formed with an upper sealing portion 151a at the upper portion in the axial direction of the shaft for oil sealing and a lower sealing portion 151b at the lower portion. The upper sealing portion 151a is formed to correspond to the sealing portion 111 and the cap portion 112 of the shaft 110, which will be described later.

In addition, the upper sealing portion 151a and the lower sealing portion 151b may be tapered for oil sealing.

The magnet 160 is mounted on an inner circumferential surface of the side wall part 153 so as to face the armature 140 formed of the core 141 and the coil 142.

In the sealing module of the hydrodynamic pressure bearing according to the first embodiment of the present invention and the spindle motor including the sleeve module, the sleeve-integrated hub may be formed of a sleeve and a hub separately and may be combined with each other.

Next, in the fixing portion, the shaft 110 rotatably supports the sleeve-integrated hub 150 as described above.

An upper sealing portion 111 for oil sealing is formed on the upper portion of the shaft 110, and a cap portion 112 for oil injection and cover is formed on the upper sealing portion.

The upper sealing portion 111 is formed with a minute gap for oil sealing with the upper sealing portion 151a of the sleeve-integrated hub 150 facing the upper sealing portion 111. The upper sealing portion 111 of the shaft and the sleeve- The upper sealing portion 151a of the valve body 150 may be selectively formed with a tapered portion for oil sealing.

The upper sealing part 111 according to the present invention is formed such that the upper sealing part 151a of the sleeve-integrated hub 150 has a thickness equal to or higher than a height that protrudes upward in the axial direction of the shaft. As such, the rigidity of the spindle motor is increased.

The cap portion 112 is positioned above the upper sealing portion to cover the upper portion of the upper sealing portion 151a of the sleeve-integrated hub 150 with respect to the axial direction of the shaft, An injection hole 112a is formed.

In other words, a tapered portion is formed on the upper sealing portion 151a of the sleeve-integrated hub, and the oil interface is formed on the upper surface of the upper sealing portion 151a, so that the oil through the oil injection hole 112a of the cap portion 112 Injection and oil interface management becomes easy.

The lower end of the shaft 110 is fixed to the holder 120 by press-fitting, adhesion, or the like. To this end, the lower end of the shaft is formed to correspond to the inner peripheral portion of the holder.

Next, the holder 120 is fixedly coupled to the lower end of the shaft 110 to support the shaft, thereby forming the sleeve-integrated hub and the lower sealing portion. To this end, the holder is formed to have an opposite surface to the sleeve-integrated hub with respect to the radial direction of the shaft, and the opposing surfaces of the sleeve-integrated hub and the holder facing each other may be configured to have a tapered shape selectively for oil sealing.

The holder 120 is press-fitted into the inner circumference of the base 130 and an armature 140 made of a core 141 and a coil 142 is press-fitted or adhered to the outer circumference of the base 130, And the like.

In addition, in the spindle motor according to the present invention, the holder 120 and the base 130 may be integrally formed.

Accordingly, the sealing module of the hydrodynamic pressure bearing according to the first embodiment of the present invention and the spindle motor including the same provide easy oil injection and interface management by the oil injection hole 112a of the shaft 110 , Leakage of the oil is prevented by the cap portion 112a. Further, the stiffness of the spindle motor is increased as the thickness of the upper sealing portion of the shaft is increased. That is, since the shaft includes the function of the cap portion, the spindle motor can be realized more efficiently and simplerly without including a separate cap or cover, and a stiff and increased spindle motor can be obtained.

2 is a cross-sectional view schematically showing a spindle motor according to a second embodiment of the present invention. The spindle motor 200 includes a stationary portion including a shaft 210, a holder 220, a base 230, an armature 240 composed of a core 241 and a coil 242, The hydraulic fluid pressure bearing is formed between the rotary part and the fixed part by filling the oil as the working fluid and the shaft 210 and the sleeve integrated hub 250 And the shaft is opposed to the oil sealing portion to form an oil injection hole, and a cover portion 213 for covering at least a part of the sleeve-integrated hub is formed.

The sleeve-integrated hub 250 is rotatably supported by the shaft 220. The inner diameter of the sleeve-integrated hub 250 is larger than the diameter of the outer diameter of the shaft 210, And the radial dynamic pressure bearing portion is filled with oil at the minute intervals. To this end, a dynamic pressure generating groove is optionally formed in the inner diameter portion of the sleeve or the outer diameter portion of the shaft.

The sleeve-integrated hub 250 includes a sleeve portion 251 which is opposed to the shaft and has a cylindrical shape, a disc portion 252 extending radially outward from the sleeve portion 251, And a side wall portion 253 extending downward in the axial direction of the shaft at the radially outer end portion.

In the sleeve 251, an upper sealing portion 251a is formed at an upper portion in an axial direction of the shaft for oil sealing, and a lower sealing portion 251b is formed at a lower portion. The upper sealing portion 251a is formed to correspond to the sealing portion 211 and the cap portion 212 of the shaft 210, which will be described later.

The upper sealing portion 251a and the lower sealing portion 251b may be tapered for oil sealing.

The magnet 260 is mounted on the inner circumferential surface of the side wall 253 so as to face the armature 240 composed of the core 241 and the coil 242.

In the spindle motor according to the second embodiment of the present invention, the sleeve-integrated hub may have a sleeve and a hub separately and may be combined with each other.

Next, in the fixing portion, the shaft 210 rotatably supports the sleeve-integrated hub 250 as described above.

An upper sealing portion 211 for sealing the oil is formed on the upper portion of the shaft 210 and a cap portion 212 for oil injection and cover is formed on the upper sealing portion 211. The cap portion 212 is formed to extend from the upper sealing portion 211 in the radial direction of the shaft. A cover portion 213 is formed to cover at least a portion of the upper sealing portion 251a of the sleeve-integrated hub 250. The cover portion 213 is formed to extend downward in the axial direction of the shaft 210 from the cap portion 212. That is, the cover portion 213 surrounds the upper sealing portion 251a of the sleeve-integrated hub 250 to prevent the sleeve-integrated hub from being shaken due to an external impact or the like, thereby realizing a more robust spindle motor.

As described above, the shaft 210 has a groove formed by the upper sealing portion 211, the cap portion 212, and the cover portion 213, and the upper sealing portion 251a of the sleeve- Is inserted.

In addition, the upper sealing portion 211 of the shaft has a small gap for oil sealing with the upper sealing portion 251a of the sleeve-integrated hub 150 facing the upper sealing portion 211, and the upper sealing portion 211 of the shaft and the upper sealing portion 251a of the sleeve- The upper sealing portion 251a of the sleeve-integrated hub 250 may optionally be formed with a tapered portion for oil sealing.

The upper sealing part 211 according to the present invention is formed such that the upper sealing part 251a of the sleeve-integrated hub 250 has a thickness equal to or higher than a height that protrudes upward in the axial direction of the shaft. As such, the rigidity of the spindle motor is increased.

The cap portion 212 is positioned above the upper sealing portion to cover the upper portion of the upper sealing portion 251a of the sleeve-integrated hub 250 with respect to the axial direction of the shaft, An oil injection hole 212a is formed.

In this case, an oil seal is formed on the upper sealing portion 251a of the sleeve-integrated hub, and the oil interface is formed on the upper surface of the upper sealing portion 251a. Accordingly, the oil through the oil injection hole 212a of the cap portion 212 Injection and oil interface management becomes easy.

In addition, the lower end of the shaft 210 is fixed to the holder 220 by press fitting, adhesion, or the like. To this end, the lower end of the shaft 210 is formed to correspond to the inner peripheral portion of the holder 220.

Next, the holder 220 supports the shaft 210 by fixing the lower end of the shaft 210 as described above, and forms a lower sealing portion at the opposite portion to the sleeve-integrated hub 250. To this end, the holder is configured to have an opposite surface to the sleeve-integral hub 250 relative to the radial direction of the shaft 210, and the opposing surfaces of the sleeve-integrated hub and holder 220 facing each other are selectively tapered Shape.

The holder 220 is press-fitted into the inner circumference of the base 230 and the armature 240 including the core 241 and the coil 242 is press-fitted or adhered to the outer circumference of the base 230, And the like.

In addition, in the spindle motor according to the present invention, the holder 220 and the base 230 may be integrally formed.

The spindle motor according to the second embodiment of the present invention is easy to inject oil and interface with the oil injection hole 212a of the shaft 210, And a part of the sleeve-integrated hub is supported by the cover part 213a, the shaking is prevented by the external impact, and the spindle motor is more firmly realized. In addition, the stiffness of the spindle motor is increased as the thickness of the upper sealing portion of the shaft is increased. As a result, since the shaft includes the function of the cap portion, it is possible to provide a spindle motor that is more efficient and simple as well as more rigid and increased in stability without including a separate cap or cover.

3 is a partial cross-sectional view schematically showing a cap portion of a shaft according to another embodiment of the spindle motor according to the first and second embodiments shown in Figs. 1 and 2 of the present invention. As shown in the figure, the cap portion 312 is provided with an oil injection hole 312a, and the oil injection hole 312a is formed to have a wide oil injection area for easy oil injection and management, , And a funnel shape.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification and the modification are possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100, 200: spindle motor
110, 210: shaft 120, 220: holder
130, 230: base 140, 240: armature
141, 241: core 142, 242: coil
150, 250: Sleeve-integrated hub 160, 260: Magnet
151a, 251a: Upper sealing portion 151b, 251b: Lower sealing portion
151, 251: Sleeve portion 152, 252:
153, 253: side wall portion 111, 211: upper sealing portion
112, 212, 312: cap part 213: cover part
112a, 212a, 312a: oil injection hole

Claims (11)

A rotating portion including a sleeve, a hub coupled to the sleeve, and a magnet coupled to an inner circumferential surface of the hub; And
And a fixing unit including a shaft for rotatably supporting the sleeve, a holder to which the shaft is fixedly coupled, a base to which the holder is coupled, and an armature coupled to the outer periphery of the base so as to face the magnet, Fluid as a working fluid is injected to form a fluid dynamic pressure bearing portion between the rotating portion and the fixed portion,
An oil sealing portion is formed at an opposite portion of the shaft and the sleeve-integrated hub, and the shaft is opposed to the oil sealing portion to form an oil injection hole.
The method according to claim 1,
Wherein the sleeve and the hub are integrally formed of a sleeve-integrated hub.
The method of claim 2,
The sleeve-
A sleeve portion facing the shaft and formed into a cylindrical shape;
A disc portion extending radially outward from the sleeve portion; And
And a sidewall portion extending downward in the axial direction of the shaft at a radially outer end of the disk portion.
The method of claim 3,
The sleeve portion
Wherein an upper sealing portion is formed on an upper portion in an axial direction of the shaft for oil sealing and a lower sealing portion is formed on a lower portion.
The method of claim 4,
Wherein the upper sealing portion and the lower sealing portion are tapered.
The method of claim 3,
Wherein the shaft is formed such that the upper sealing portion for sealing is opposed to the upper sealing portion of the sleeve.
The method of claim 6,
Wherein the shaft further comprises a cap portion extending to the upper sealing portion and positioned above the upper sealing portion of the sleeve-integrated hub.
The method of claim 6,
Wherein an oil injection hole is formed in the cap portion of the shaft.
The method of claim 8,
Wherein the oil injection hole is formed so that an injection part into which oil is injected is wide and a discharge port of the oil has a narrow funnel shape.
The method of claim 6,
Wherein the upper sealing portion of the shaft further comprises a cover portion surrounding at least a portion of the sleeve-integrated hub.
The method of claim 10,
Wherein the cover portion surrounds the upper sealing portion of the sleeve-integrated hub.

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